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Sample records for chelate-modified fenton reaction

  1. Chelate-Modified Fenton Reaction for the Degradation of Trichloroethylene in Aqueous and Two-Phase Systems

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, Scott [Univ of KY, dept of chemical and materials engineering; lynch, Andrew [Univ of KY, dept of chemical and materials engineering; Bachas, Leonidas [Univ of KY, Dept of Chemistry; hampson, Steve [Univ of KY Center for Applied Energy Research - KY Research Consortium of Energy and Environment; Ormsbee, Lindelle [Univ of KY Center for Applied Energy Research - KY Research Consortium of Energy and Environment; Bhattacharyya, Dibakar [Univ of KY, dept of chemical and materials engineering

    2008-06-01

    The Standard Fenton reaction has been used for In-Situ Chemical Oxidation (ISCO) of toxic organics in groundwater. However, it requires low pH operating conditions, and thus has limitations for in situ applications. In addition, hydroxyl radicals are rapidly consumed by hydroxyl scavengers found in the subsurface. These problems are alleviated through the chelate-modified Fenton (hydroxyl radical) reaction, which includes the addition of nontoxic chelate (L) such as citrate or gluconic acid. This chelate allows the reaction to take place at bear neutral pH and control hydrogen peroxide consumption by binding to Fe(II), forming an FeL complex. The chelate also binds to Fe(III), preventing its precipitation as ferric hydroxide and thus prevents problems associated with injection well plugging. The rate of TCE dechlorination in chelate-modified Fenton systems is a function of pH, H2O2 concentration, and FE:L ratio. The primary objective of this research is to model and apply this process to the destruction of trichloroethylene (TCE) present in both the aqueous and organic (in the form of droplets) phases. Experimentation proved the chelate-modified Fenton reaction effectively dechlorinates TCE in both the aqueous and organic phases at near-neutral pH. Other focuses of this work include determining the effect of [L]:[Fe] ratios on H2O2 and TCE degradation as well as reusability of the FE citrate solution under repeated H2O2 injections. Generalized models were developed to predict the concentration of TCE in the aqueous phase and TCE droplet radius as a function of time using established hydroxyl radial kinetics and mass transfer relationships.

  2. Degradation of p-hydroxyphenylacetic acid by photoassisted Fenton reaction.

    Science.gov (United States)

    Acero, L L; Benítez, F J; Real, F J; Leal, A I

    2001-01-01

    The chemical decomposition of p-hydroxyphenylacetic acid, a phenolic pollutant present in agro-industrial plant effluents, has been investigated by means of the Fenton's reaction and the photoassisted Fenton's reaction, the so-called photo-Fenton system. The degradation levels achieved have been compared to those obtained by applying other Advanced Oxidation Processes, such as the combination UV/H2O2. The optimum pH to carry out the decomposition of this organic compound by either Fenton or photo-Fenton systems was found to be pH = 3. The presence of buffers such as phosphate impedes these processes due to the formation of ferric complexes. A reaction mechanism, which allows calculating the contribution of the radical reaction to the global process, has been proposed. According to this mechanism, the dominant way of degradation of p-hydroxyphenylacetic acid is through its reaction with the OH radicals originated in the photolysis of H2O2 and, especially, in the Fenton's reaction. PMID:11695475

  3. Magnetic field assisted Fenton reactions for the enhanced degradation of methyl blue

    Institute of Scientific and Technical Information of China (English)

    Xiao Long Hao; Lu Yi Zou; Guang Sheng Zhang; Yi Bo Zhang

    2009-01-01

    Magnetic field was tentatively introduced into Fenton reactions system for the degradation and discoloration of methyl blue as the represent of organic chemical dye, which was a bio-refractory organic pollutant in industry wastewater. It was found that under optimal Fenton reaction conditions, with the assistant of magnetic field in Fenton reactions, the degradation rate of methyl blue, the decomposition rate of H2O2 and the conversion rate of Fe2+ were accelerated, the extent of them would be improved by the increase of magnetic field intensity. Meanwhile, the mineralization of methyl blue (CODcr) was improved by over 10% with magnetic fiold.

  4. Degradation of Anthraquinone Dye Reactive Blue 4 in Pyrite Ash Catalyzed Fenton Reaction

    Directory of Open Access Journals (Sweden)

    Milena Becelic-Tomin

    2014-01-01

    Full Text Available Pyrite ash (PA is created by burning pyrite in the chemical production of sulphuric acid. The high concentration of iron oxide, mostly hematite, present in pyrite ash, gives the basis for its application as a source of catalytic iron in a modified Fenton process for anthraquinone dye reactive blue 4 (RB4 degradation. The effect of various operating variables such as catalyst and oxidant concentration, initial pH and RB4 concentration on the abatement of total organic carbon, and dye has been assessed in this study. Here we show that degradation of RB4 in the modified Fenton reaction was efficient under the following conditions: pH=2.5; [PA]0=0.2 g L−1; [H2O2]0=5 mM and initial RB4 concentration up to 100 mg L−1. The pyrite ash Fenton reaction can overcome limitations observed from the classic Fenton reaction, such as the early termination of the Fenton reaction. Metal (Pb, Zn, and Cu content of the solution after the process suggests that an additional treatment step is necessary to remove the remaining metals from the water. These results provide basic knowledge to better understand the modified, heterogeneous Fenton process and apply the PA Fenton reaction for the treatment of wastewaters which contains anthraquinone dyes.

  5. In Vivo Lighted Fluorescence via Fenton Reaction: Approach for Imaging of Hydrogen Peroxide in Living Systems.

    Science.gov (United States)

    Liu, Changhui; Chen, Weiju; Qing, Zhihe; Zheng, Jing; Xiao, Yue; Yang, Sheng; Wang, Lili; Li, Yinhui; Yang, Ronghua

    2016-04-01

    By virtue of its high sensitivity and rapidity, Fenton reaction has been demonstrated as a powerful tool for in vitro biochemical analysis; however, in vivo applications of Fenton reaction still remain to be exploited. Herein, we report, for the first time, the design, formation and testing of Fenton reaction for in vivo fluorescence imaging of hydrogen peroxide (H2O2). To realize in vivo fluorescence imaging of H2O2 via Fenton reaction, a functional nanosphere, Fc@MSN-FDNA/PTAD, is fabricated from mesoporous silica nanoparticle (MSN), a Fenton reagent of ferrocene (Fc), ROX-labeled DNA (FDNA), and a cationic perylene derivative (PTAD). The ferrocene molecules are locked in the pore entrances of MSN, and exterior of MSN is covalently immobilized with FDNA. As a key part, PTAD acts as not only the gatekeeper of MSN but also the efficient quencher of ROX. H2O2 can permeate into the nanosphere and react with ferrocene to product hydroxyl radical (·OH) via Fenton reaction, which cleaves FDNA to detach ROX from PTAD, thus in turn, lights the ROX fluorescence. Under physiological condition, H2O2 can be determined from 5.0 nM to 1.0 μM with a detection limit of 2.4 nM. Because of the rapid kinetics of Fenton reaction and high specificity for H2O2, the proposed method meets the requirement for real applications. The feasibility of Fc@MSN-FDNA/PTAD for in vivo applications is demonstrated for fluorescence imaging of exogenous and endogenous H2O2 in cells and mice. We expect that this work will not only contribute to the H2O2-releated studies but also open up a new way to exploit in vivo Fenton reaction for biochemical research. PMID:26948406

  6. A characterization of the two-step reaction mechanism of phenol decomposition by a Fenton reaction

    Science.gov (United States)

    Valdés, Cristian; Alzate-Morales, Jans; Osorio, Edison; Villaseñor, Jorge; Navarro-Retamal, Carlos

    2015-11-01

    Phenol is one of the worst contaminants at date, and its degradation has been a crucial task over years. Here, the decomposition process of phenol, in a Fenton reaction, is described. Using scavengers, it was observed that decomposition of phenol was mainly influenced by production of hydroxyl radicals. Experimental and theoretical activation energies (Ea) for phenol oxidation intermediates were calculated. According to these Ea, phenol decomposition is a two-step reaction mechanism mediated predominantly by hydroxyl radicals, producing a decomposition yield order given as hydroquinone > catechol > resorcinol. Furthermore, traces of reaction derived acids were detected by HPLC and GS-MS.

  7. The Potential Controlled Fenton Reaction at Liquid/Liquid Interfaces as the Source of Hydroxyl Radicals

    Czech Academy of Sciences Publication Activity Database

    Brusová, Z.; Štulík, K.; Mareček, Vladimír

    2004-01-01

    Roč. 563, 1/2 (2004), s. 277-281. ISSN 0022-0728 R&D Projects: GA MŠk ME 510 Institutional research plan: CEZ:AV0Z4040901 Keywords : liquid/liquid interfaces * homogeneous reaction * Fenton reaction Subject RIV: CG - Electrochemistry Impact factor: 2.228, year: 2004

  8. Fenton like reactions of methyl- and ethylhydroperoxide with Fe2+ in Tropospheric liquid aerosols.

    Science.gov (United States)

    Chevallier, E.; Durand Jolibois, R.; Monod, A.; Carlier, P.

    2003-04-01

    The classical reaction of Fe2+ with H_2O_2, known as the Fenton reaction, generates OH radicals according to: Fe2+ + H_2O_2 rightarrow Fe3+ + OH + OH^- with k_0=5.15x10^8exp(-39.3x10^3/RT)M-1s-1 in aqueous solutions at pH = 1. Organic hydroperoxides are ubiquitous compounds in the atmosphere and especially in. The aim of this study is to determine possible reactions of methylhydroperoxide and ethylhydroperoxide with Fe2+, in Fenton like reactions under tropospheric conditions. The experiments were performed in a static inactinique reactor equipped with an oximeter. Analysis of reaction products were performed by specific chromatographic methods (GC-FID, HPLC-UV, HPLC-fluorimetry and IC-conductimetry). Kinetic results and possible mechanisms are presented. The rate constant obtained at 6C^o and pH=2 is respectively (36±11) M-1s-1 and (24±5) M-1s-1. Fe2+ reduction by MHP and EHP produce the associated aldehydes, i.e. formaldehyde and acethaldehyde respectively. The proposed mechanism for is a Fenton like mechanism, producing the corresponding alkoxyl radical (Fenton type radical), i.e. Fe2+ + ROOH rightarrow Fe3+ + OH^- + RO. The impact of these reactions on tropospheric multiphase chemistry is discussed.

  9. Mechanistic aspects of the Fenton reaction under conditions approximated to the extracellular fluid.

    Science.gov (United States)

    Freinbichler, Wolfhardt; Tipton, Keith F; Corte, Laura Della; Linert, Wolfgang

    2009-01-01

    The Fenton reaction was investigated, in a medium approximating to that of the extracellular fluid (ECF), by rapid-mixing stopped flow experiments and HPLC analysis using sodium terephthalate (TA(2-)). The reactive intermediate of the Fenton reaction hydroxylates the essentially nonfluorescent, TA(2-) to the brilliant fluorophor 2-hydroxy-terephthalate (OH-TA), which allows the Fenton reaction to be monitored in stopped-flow experiments. There was no artefactual quenching of the fluorescence by substances present in the Fenton-reaction mixture or in the artificial cerebrospinal fluid (aCSF) that might have influenced OH-TA quantification. A mathematical model based on kinetic considerations was developed. This explains the observed independence of the OH-TA concentration on the amount of TA(2-) present in aCSF as well as its dependence on TA(2-) concentration in potassium acetate buffer. A mechanism based on this model, involving complex formation between Fe(II), TA(2-) and H(2)O(2), followed by an intra-molecular hydroxylation accompanied by an intra-molecular electron transfer was developed. The results are consistent with a reactive intermediate, which causes oxidative stress in vivo, not being a free hydroxyl radical, but a ferryl species or a "crypto" radical. The biological implications of these results are discussed. PMID:18848726

  10. Fenton reaction induced cancer in wild type rats recapitulates genomic alterations observed in human cancer.

    Directory of Open Access Journals (Sweden)

    Shinya Akatsuka

    Full Text Available Iron overload has been associated with carcinogenesis in humans. Intraperitoneal administration of ferric nitrilotriacetate initiates a Fenton reaction in renal proximal tubules of rodents that ultimately leads to a high incidence of renal cell carcinoma (RCC after repeated treatments. We performed high-resolution microarray comparative genomic hybridization to identify characteristics in the genomic profiles of this oxidative stress-induced rat RCCs. The results revealed extensive large-scale genomic alterations with a preference for deletions. Deletions and amplifications were numerous and sometimes fragmented, demonstrating that a Fenton reaction is a cause of such genomic alterations in vivo. Frequency plotting indicated that two of the most commonly altered loci corresponded to a Cdkn2a/2b deletion and a Met amplification. Tumor sizes were proportionally associated with Met expression and/or amplification, and clustering analysis confirmed our results. Furthermore, we developed a procedure to compare whole genomic patterns of the copy number alterations among different species based on chromosomal syntenic relationship. Patterns of the rat RCCs showed the strongest similarity to the human RCCs among five types of human cancers, followed by human malignant mesothelioma, an iron overload-associated cancer. Therefore, an iron-dependent Fenton chemical reaction causes large-scale genomic alterations during carcinogenesis, which may result in distinct genomic profiles. Based on the characteristics of extensive genome alterations in human cancer, our results suggest that this chemical reaction may play a major role during human carcinogenesis.

  11. Applicability of the Photo-Fenton reaction for treating water containing natural phenolic pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Gernjak, W.; Krutzler, T.; Malato, S.; Caceres, J.; Bauer, R.

    2001-07-01

    Phenolic compounds are known to be present in high concentrations in various types of agro-industrial wastes. As they are highly Biorecalcitrant a possible treatment by Advanced Oxidation Processes has to be investigated. Therefore in the present work six phenolic model compounds were chosen and their degradability by means of the Photo-Fenton reaction was proved as well using an UV-Lamp in laboratory experiments in Vienna as using sunlight in pilot-plant experiments at the Plataforma Solar in Spain. All compounds could be mineralized completely. Neither in experiments with single substances nor in a more complex matrix using a mixture of phenols non-degradable intermediates were produced. Comparing the decrease of total organic carbon and total phenol content could prove the expected selectivity to phenolic compounds of the Photo Fenton reaction. (Author) 12 refs.

  12. Fenton reaction-based colorimetric immunoassay for sensitive detection of brevetoxin B.

    Science.gov (United States)

    Lai, Wenqiang; Wei, Qiaohua; Zhuang, Junyang; Lu, Minghua; Tang, Dianping

    2016-06-15

    We designed a new colorimetric immunoassay for sensitive monitoring of brevetoxin B (BTB) using enzyme-controlled Fenton reaction with a high-resolution 3,3',5,5'-tetramethylbenzidine (TMB)-based visual colored system. Upon addition of hydrogen peroxide (H2O2), the equivalent iron(II) could be first converted into iron(III) and free hydroxyl radical (•OH) via the classical Fenton reaction. Then the as-produced iron(III) and •OH could cause a perceptible change from colorless to blue with the increasing H2O2 concentration in the presence of TMB. Based on Fenton reaction-triggered visual colored system, a novel competitive-type colorimetric enzyme immunoassay was developed for the quantitative screening of target BTB on the bovine serum albumin-BTB-modified magnetic bead using glucose oxidase/anti-BTB antibody-labeled gold nanoparticle as the signal-transduction tag. Upon target BTB introduction, the analyte competed with the conjugated BTB on the magnetic bead for anti-BTB antibody on gold nanoparticle. The carried glucose oxidase with the gold nanoparticle could implement the oxidation of glucose to produce H2O2, and the generated H2O2 promoted the above-mentioned Fenton reaction for color development. Under the optimal conditions, the absorbance decreased with the increasing target BTB in the range from 0.1 to 150 ng kg(-1) with a low detection limit (LOD) of 0.076 ng kg(-1). The LOD was 500-fold lower than that of commercialized Abraxis BTB ELISA kit. Non-specific adsorption was not observed. The precision, reproducibility and specificity were acceptable. Finally, the method accuracy was also validated for monitoring spiked seafood samples, giving results well matched with the referenced brevetoxin ELISA kit. PMID:26851583

  13. Iron oxide nanotube layer fabricated with electrostatic anodization for heterogeneous Fenton like reaction

    International Nuclear Information System (INIS)

    Highlights: • Iron oxide nanotube was newly fabricated with potentiostatic anodization of Fe0 foil. • Cyanide was oxidized more effectively with the iron oxide nanotube and H2O2, resulting in fast oxidation of cyanide and cyanate. • This nanotube of Fe2O3 on Fe0 metal can replace conventional particulate iron catalysts in Fenton-like processes. - Abstract: Iron oxide nanotubes (INT) were fabricated with potentiostatic anodization of zero valent iron foil in 1 M Na2SO4 containing 0.5 wt% NH4F electrolyte, holding the potential at 20, 40, and 60 V for 20 min, respectively. Field emission scanning electron microscopy and X-ray diffractometry were used to evaluate the morphology and crystalline structure of the INT film. The potential of 40 V for 20 min was observed to be optimal to produce an optimal catalytic film. Cyanide dissolved in water was degraded through the Fenton-like reaction using the INT film with hydrogen peroxide (H2O2). In case of INT-40 V in the presence of H2O2 3%, the first-order rate constant was found to be 1.7 × 10−2 min−1, and 1.2 × 10−2 min−1 with commercial hematite powder. Degradation of cyanide was much less with only H2O2. Therefore, this process proposed in this work can be an excellent alternative to traditional catalysts for Fenton-like reaction

  14. Accelerated Catalytic Fenton Reaction with Traces of Iron: An Fe-Pd-Multicatalysis Approach.

    Science.gov (United States)

    Georgi, Anett; Velasco Polo, Miriam; Crincoli, Klara; Mackenzie, Katrin; Kopinke, Frank-Dieter

    2016-06-01

    An accelerated catalytic Fenton (ACF) reaction was developed based upon a multicatalysis approach, facilitating efficient contaminant oxidation at trace levels of dissolved iron. Beside the Fe(II)/H2O2 catalyst/oxidant pair for production of OH-radicals, the ACF system contains Pd/H2 as catalyst/reductant pair for fast reduction of Fe(III) back to Fe(II) which accelerates the Fenton cycle and leads to faster contaminant degradation. By this means, the concentration of the dissolved iron catalyst can be reduced to trace levels (1 mg L(-1)) below common discharge limits, thus eliminating the need for iron sludge removal, which is one of the major drawbacks of conventional Fenton processes. ACF provides fast degradation of the model contaminant methyl tert-butyl ether (MTBE, C0 = 0.17 mM) with a half-life of 11 min with 1 mg L(-1) dissolved iron, 500 mg L(-1) H2O2, 5 mg L(-1) Pd (as suspended Pd/Al2O3 catalyst) and 0.1 MPa H2, pH 3. The effects of pH, H2 partial pressure and H2O2 concentration on MTBE degradation rates were studied. Results on kinetic deuterium isotope effect and quenching studies are in conformity with OH-radicals as main oxidant. The heterogeneous Pd/Al2O3 catalyst was reused within six cycles without significant loss in activity. PMID:27167833

  15. Catalytic degradation of methylene blue by Fenton like system:model to the environmental reaction

    Institute of Scientific and Technical Information of China (English)

    Sanjay R. Thakare

    2004-01-01

    To develop more efficient chemical methods for the demineralization of organic pollutants from waterbodies, which one was also mimic to the nature, a degradation of methylene blue by Fe( Ⅲ ) and H2O2 in theabsence of light instead of Fe( Ⅱ ) and H2O2 was studied. Results showed that use of Fe ( Ⅲ ) is more promisingthan Fe( Ⅱ ). The present study reflects that Fenton reaction is more efficient, in the presence of a small amount ofsalicylic acid is added which is a one of the priority pollutant.

  16. A Peptide-mediated Fenton Reaction in Wood-degrading Fungi

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Gt factor is a low-molecular-weight peptide isolated from the extracellular culture of wood-degrading fungus Gloeophyllum trabeum. It is capable of enhancing degradation of cellulose. Its action mechanism was investigated and it was found that Gt factor could reduce Fe3+ to Fe2+. Electron paramagnetic resonance (EPR) spectroscopy revealed in the presence of O2, Gt factor could drive the formation of H2O2 via a superoxide anion O2.- intermediate and mediate the generation of hydroxyl radical HO˙ in a Fenton-type reaction. All these provided evidence for the formation of HO˙ in some wood-degrading fungi.

  17. Kinetics and optimization on discoloration of dyeing wastewater by schorl-catalyzed fenton-like reaction

    Directory of Open Access Journals (Sweden)

    Xu Huan-Yan

    2014-01-01

    Full Text Available Kinetics and optimization on the discoloration of an active commercial dye, Argazol Blue BFBR (ABB by heterogeneous Fenton-like reaction catalyzed by natural schorl were investigated in this study. Kinetic investigations revealed that the first-order kinetic model was more favorable to describe the discoloration of ABB at different reaction conditions than the second-order and Behnajady-Modirshahla-Ghanbery models. The relationship between the reaction rate constant k and reaction temperature T followed the Arrhenius equation, with the apparent activation energy Ea of 51.31kJ•mol-1. The central composite design under the response surface methodology was employed for the experimental design and optimization of the ABB discoloration process. The significance of a second order polynomial model for predicting the optimal values of ABB discoloration was evaluated by the analysis of variance and 3D response surface plots for the interactions between two variables were constructed. Then, the optimum conditions were determined.

  18. Sulfurized limonite as material for fast decomposition of organic compounds by heterogeneous Fenton reaction

    Energy Technology Data Exchange (ETDEWEB)

    Toda, Kei, E-mail: todakei@sci.kumamoto-u.ac.jp [Department of Chemistry, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Tanaka, Toshinori; Tsuda, Yutaka; Ban, Masahiro; Koveke, Edwin P. [Department of Chemistry, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Koinuma, Michio [Department of Chemistry and Biochemistry, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Ohira, Shin-Ichi [Department of Chemistry, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan)

    2014-08-15

    Graphical abstract: - Highlights: • Used limonite degrades organic compounds by heterogeneous Fenton reaction. • Sulfurized limonite removes methylene blue color in seconds. • Recycled limonite can be used for biogas purification and wastewater treatment. - Abstract: Rapid decomposition of wastewater contaminants using sulfurized limonite (S-limonite) was investigated. Limonite is used for desulfurization of biogases, and S-limonite is obtained from desulfurization plants as solid waste. In this work, the profitable use of S-limonite in water treatment was examined. The divalent Fe in S-limonite was expected to produce OH radicals, as Fe{sup 2+} ions and limonite thermally treated with H{sub 2} do. Methylene blue was used for batch-wise monitoring of the decomposition performance. The decomposition rate was fast and the methylene blue solution color disappeared in only 10 s when a small amount of H{sub 2}O{sub 2} was added (1 mM in the sample solution) in the presence of S-limonite. The OH radicals were formed by a heterogeneous reaction on the S-limonite surface and Fenton reaction with dissolved Fe{sup 2+}. The decomposition of pentachlorophenol was also examined; it was successfully decomposed in batch-wise tests. The surfaces of limonite before sulfurization, S-limonite, and S-limonite after use for water treatment were performed using scanning electron microscopy and X-ray photoelectron spectroscopy. The results show that S-limonite reverted to limonite after being used for water treatment.

  19. Sulfurized limonite as material for fast decomposition of organic compounds by heterogeneous Fenton reaction

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Used limonite degrades organic compounds by heterogeneous Fenton reaction. • Sulfurized limonite removes methylene blue color in seconds. • Recycled limonite can be used for biogas purification and wastewater treatment. - Abstract: Rapid decomposition of wastewater contaminants using sulfurized limonite (S-limonite) was investigated. Limonite is used for desulfurization of biogases, and S-limonite is obtained from desulfurization plants as solid waste. In this work, the profitable use of S-limonite in water treatment was examined. The divalent Fe in S-limonite was expected to produce OH radicals, as Fe2+ ions and limonite thermally treated with H2 do. Methylene blue was used for batch-wise monitoring of the decomposition performance. The decomposition rate was fast and the methylene blue solution color disappeared in only 10 s when a small amount of H2O2 was added (1 mM in the sample solution) in the presence of S-limonite. The OH radicals were formed by a heterogeneous reaction on the S-limonite surface and Fenton reaction with dissolved Fe2+. The decomposition of pentachlorophenol was also examined; it was successfully decomposed in batch-wise tests. The surfaces of limonite before sulfurization, S-limonite, and S-limonite after use for water treatment were performed using scanning electron microscopy and X-ray photoelectron spectroscopy. The results show that S-limonite reverted to limonite after being used for water treatment

  20. Iron oxide nanotube layer fabricated with electrostatic anodization for heterogeneous Fenton like reaction

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Jun-Won; Park, Jae-Woo, E-mail: jaewoopark@hanyang.ac.kr

    2014-05-01

    Highlights: • Iron oxide nanotube was newly fabricated with potentiostatic anodization of Fe{sup 0} foil. • Cyanide was oxidized more effectively with the iron oxide nanotube and H{sub 2}O{sub 2}, resulting in fast oxidation of cyanide and cyanate. • This nanotube of Fe{sub 2}O{sub 3} on Fe{sup 0} metal can replace conventional particulate iron catalysts in Fenton-like processes. - Abstract: Iron oxide nanotubes (INT) were fabricated with potentiostatic anodization of zero valent iron foil in 1 M Na{sub 2}SO{sub 4} containing 0.5 wt% NH{sub 4}F electrolyte, holding the potential at 20, 40, and 60 V for 20 min, respectively. Field emission scanning electron microscopy and X-ray diffractometry were used to evaluate the morphology and crystalline structure of the INT film. The potential of 40 V for 20 min was observed to be optimal to produce an optimal catalytic film. Cyanide dissolved in water was degraded through the Fenton-like reaction using the INT film with hydrogen peroxide (H{sub 2}O{sub 2}). In case of INT-40 V in the presence of H{sub 2}O{sub 2} 3%, the first-order rate constant was found to be 1.7 × 10{sup −2} min{sup −1}, and 1.2 × 10{sup −2} min{sup −1} with commercial hematite powder. Degradation of cyanide was much less with only H{sub 2}O{sub 2}. Therefore, this process proposed in this work can be an excellent alternative to traditional catalysts for Fenton-like reaction.

  1. Application of non-thermal plasma reactor and Fenton reaction for degradation of ibuprofen

    Energy Technology Data Exchange (ETDEWEB)

    Marković, Marijana [Center of Chemistry, Institute of Chemistry, Technology and Metallurgy, University of Belgrade, Studentski trg 12-16, 11000 Belgrade (Serbia); Jović, Milica; Stanković, Dalibor [Innovation Center, Faculty of Chemistry, University of Belgrade, P.O. Box 51, 11058 Belgrade 118 (Serbia); Kovačević, Vesna [Faculty of Physics, University of Belgrade, P.O. Box 44, 11000 Belgrade (Serbia); Roglić, Goran [Faculty of Chemistry, University of Belgrade, P.O. Box 51, 11058 Belgrade 118 (Serbia); Gojgić-Cvijović, Gordana [Center of Chemistry, Institute of Chemistry, Technology and Metallurgy, University of Belgrade, Studentski trg 12-16, 11000 Belgrade (Serbia); Manojlović, Dragan, E-mail: manojlo@chem.bg.ac.rs [Faculty of Chemistry, University of Belgrade, P.O. Box 51, 11058 Belgrade 118 (Serbia)

    2015-02-01

    Pharmaceutical compounds have been detected frequently in surface and ground water. Advanced Oxidation Processes (AOPs) were reported as very efficient for removal of various organic compounds. Nevertheless, due to incomplete degradation, toxic intermediates can induce more severe effects than the parent compound. Therefore, toxicity studies are necessary for the evaluation of possible uses of AOPs. In this study the effectiveness and capacity for environmental application of three different AOPs were estimated. They were applied and evaluated for removal of ibuprofen from water solutions. Therefore, two treatments were performed in a non-thermal plasma reactor with dielectric barrier discharge with and without a homogenous catalyst (Fe{sup 2+}). The third treatment was the Fenton reaction. The degradation rate of ibuprofen was measured by HPLC-DAD and the main degradation products were identified using LC–MS TOF. Twelve degradation products were identified, and there were differences according to the various treatments applied. Toxicity effects were determined with two bioassays: Vibrio fischeri and Artemia salina. The efficiency of AOPs was demonstrated for all treatments, where after 15 min degradation percentage was over 80% accompanied by opening of the aromatic ring. In the treatment with homogenous catalyst degradation reached 99%. V. fischeri toxicity test has shown greater sensitivity to ibuprofen solution after the Fenton treatment in comparison to A. salina. - Highlights: • Twelve ibuprofen degradation products were identified in total. • The degradation percentage differed between treatments (DBD/Fe{sup 2+} was 99%). • In DBD/Fe{sup 2+} only aliphatic degradation products were identified. • V. fischeri was sensitive to ibuprofen solution after the Fenton treatment. • A. salina showed no toxic effect when exposed to all post treatment solutions.

  2. Application of non-thermal plasma reactor and Fenton reaction for degradation of ibuprofen

    International Nuclear Information System (INIS)

    Pharmaceutical compounds have been detected frequently in surface and ground water. Advanced Oxidation Processes (AOPs) were reported as very efficient for removal of various organic compounds. Nevertheless, due to incomplete degradation, toxic intermediates can induce more severe effects than the parent compound. Therefore, toxicity studies are necessary for the evaluation of possible uses of AOPs. In this study the effectiveness and capacity for environmental application of three different AOPs were estimated. They were applied and evaluated for removal of ibuprofen from water solutions. Therefore, two treatments were performed in a non-thermal plasma reactor with dielectric barrier discharge with and without a homogenous catalyst (Fe2+). The third treatment was the Fenton reaction. The degradation rate of ibuprofen was measured by HPLC-DAD and the main degradation products were identified using LC–MS TOF. Twelve degradation products were identified, and there were differences according to the various treatments applied. Toxicity effects were determined with two bioassays: Vibrio fischeri and Artemia salina. The efficiency of AOPs was demonstrated for all treatments, where after 15 min degradation percentage was over 80% accompanied by opening of the aromatic ring. In the treatment with homogenous catalyst degradation reached 99%. V. fischeri toxicity test has shown greater sensitivity to ibuprofen solution after the Fenton treatment in comparison to A. salina. - Highlights: • Twelve ibuprofen degradation products were identified in total. • The degradation percentage differed between treatments (DBD/Fe2+ was 99%). • In DBD/Fe2+ only aliphatic degradation products were identified. • V. fischeri was sensitive to ibuprofen solution after the Fenton treatment. • A. salina showed no toxic effect when exposed to all post treatment solutions

  3. Chemical oxidation of anthracite with hydrogen peroxide via the Fenton reaction

    Science.gov (United States)

    Heard, I.; Senftle, F.E.

    1984-01-01

    Solutions of 30% H2O2 ranging from pH = 0 to pH = 11.5 have been used to oxidize anthracite at room temperature. The inorganic impurities, primarily pyrite, catalysed the oxidation and reduction of H2O2 (the Fenton reaction) to form the hydroxyl radical; the oxidation of the organic matter was minimal and was observed only in strong acidic solutions (pH reactions were completed in a much shorter time, the oxidation mechanism must have been of a different nature than that for the untreated anthracite. A qualitative model based on the catalytic decomposition of H2O2 by activated carbon sites in the coal surface is used to explain the oxidation of the demineralized anthracite. ?? 1984.

  4. Synthesis of iron/GAC catalyst for wastewater treatment using heterogeneous Fenton reaction

    Indian Academy of Sciences (India)

    S T T Le; T T Ngo; W Khanitchaidecha; A Nakaruk

    2015-08-01

    Iron catalyst dispersed on granular activated carbon (GAC) was prepared by impregnating Fe(NO3)3 solution on GAC. The mixed solution was annealed at 600°C in muffle furnace under ambient condition for 1 h. The structural property of the catalyst was investigated using X-ray diffraction (XRD). The catalyst’s activity and lifetime were tested using the degradation of 50 ppm methyl orange (MO) solution. In addition, the optimum conditions of the Fenton reaction such as initial pH, initial MO concentration hydrogen peroxide concentration and the amount of catalyst were also investigated. The XRD results showed that magnetite and haematite were two main compositions of the synthesized catalyst. The investigation of optimum conditions suggested that initial pH at 3 provided the highest efficiency of MO removal. In addition, the concentration of hydrogen peroxide at 8 ppm was the most suitable. The optimum condition of amount of catalyst was 5 g l−1. The efficiencies of MO removal reached 95% at 60 min of reaction time at low initial MO concentration (25–500 mg l−1). In the meantime, the removal efficiency was found to decrease with the increase in the initial MO concentration. The efficiency decreased to 70 and 30% at 1000 and 3000 mg l−1 of initial MO concentration, respectively. Additionally, after reuse the synthesized catalyst 3 times the MO removal efficiency still remained over 90%. In conclusion, the iron/GAC catalyst was successfully synthesized and applied to dye treatment using heterogeneous Fenton reaction. The catalyst showed high efficiency of MO removal and could be reused many times.

  5. High level of oxidized nucleosides in thyroid mitochondrial DNA; damaging effects of Fenton reaction substrates

    Directory of Open Access Journals (Sweden)

    Karbownik-Lewińska Małgorzata

    2012-12-01

    Full Text Available Abstract Background The mitochondrial DNA (mtDNA lies in close proximity to the free radical-producing electron transport chain, thus, it is highly prone to oxidative damage. Oxyphilic type of follicular thyroid carcinoma consists of cells filled – almost exclusively – with aberrant mitochondria. In turn, bivalent iron (Fe2+ and hydrogen peroxide (H2O2 are indispensable for thyroid hormone synthesis, therefore being available in physiological conditions presumably at high concentrations. They participate in Fenton reaction (Fe2++H2O2→Fe3++·OH + OH-, resulting in the formation of the most harmful free radical – hydroxyl radical (·OH. The same substrates may be used to experimentally induce oxidative damage to macromolecules. The aim of the study was to evaluate the background level of oxidative damage to mtDNA and the damaging effects of Fenton reaction substrates. Methods Thyroid mtDNA was incubated in the presence of either H2O2 [100, 10, 1.0, 0.5, 0.1, 0.001, 0.00001 mM] or FeSO4 (Fe2+ [300, 150, 30, 15, 3.0, 1.5 μM], or in the presence of those two factors used together, namely, in the presence of Fe2+ [30 μM] plus H2O2 [100, 10, 1.0, 0.5, 0.1, 0.001, 0.00001 mM], or in the presence of H2O2 [0.5 mM] plus Fe2+ [300, 150, 30, 15, 3.0, 1.5 μM]. 8-oxo-7,8-dihydro-2’-deoxyguanosine (8-oxodG concentration, as the index of DNA damage, was measured by HPLC. Results Both Fenton reaction substrates, used separately, increased 8-oxodG level for the highest H2O2 concentration of 100 mM and in Fe2+ concentration-dependent manner [300, 150, and 30 μM]. When Fe2+ and H2O2 were applied together, Fe2+ enhanced H2O2 damaging effect to a higher degree than did H2O2 on Fe2+ effect. Conclusions The level of oxidized nucleosides in thyroid mtDNA is relatively high, when compared to nuclear DNA. Both substrates of Fenton reaction, i.e. ferrous ion and hydrogen peroxide, increase oxidative damage to mtDNA, with stronger damaging effect exerted by

  6. Enhancing enzymolysis and fermentation efficiency of sugarcane bagasse by synergistic pretreatment of Fenton reaction and sodium hydroxide extraction.

    Science.gov (United States)

    Zhang, Teng; Zhu, Ming-Jun

    2016-08-01

    A study on the synergistic pretreatment of sugarcane bagasse (SCB) using Fenton reaction and NaOH extraction was conducted. The optimized process conditions for Fenton pretreatment were 10% (w/w) of H2O2, 20mM of Fe(2+), pH 2.5, pretreatment time 6h, and pretreatment temperature 55°C. Sequential pretreatments were performed in combination with NaOH extraction (NaOH 1% (w/w), 80°C, 5% of solid loading, 1h). Among all the pretreatments, Fenton pretreatment followed by NaOH extraction had the highest efficiency of 64.7% and 108.3% for enzymolysis and simultaneous saccharification fermentation (SSF) with an ethanol concentration of 17.44g/L. The analyses by the scanning electron microscopy, X-ray diffraction and confocal laser scanning microscopy revealed that Fenton pretreatment disrupts the structure of SCB to facilitate the degradation of lignin by NaOH. The overall data suggest that this combinatorial strategy is a promising process for SCB pretreatment. PMID:27213578

  7. Degradation of Corn Oil Wastes by Fenton Reaction and Under Mildly Basic Media in the Presence of Oxidants Assisted with Sun Light

    OpenAIRE

    Josefina V.  Sanchez; Susana S.  Martinez; Maria D.F.T.  Hernandez

    2008-01-01

    The degradation of water soluble corn oil wastes was carried out by Fenton reaction and also under mildly basic media in the presence of oxidants, such as hydrogen peroxide and persulfate, assisted with solar light. The degradation efficiency was obtained by analysis of chemical oxygen demand, carbon dioxide and gas chromatography. Over 90% of both chemical oxygen demand abatement and carbon dioxide recovery was accomplished by Fenton reaction. The presence of oxidants during the photodegrada...

  8. Simultaneous photoinduced generation of Fe(2+) and H2O2 in rivers: An indicator for photo-Fenton reaction.

    Science.gov (United States)

    Mostofa, Khan M G; Sakugawa, Hiroshi

    2016-09-01

    The photo-Fenton reaction is a key source of the highly reactive hydroxyl radical (HO) that is produced by the reaction of simultaneous photo-induced generation of Fe(2)(+)-dissolved organic matter (DOM) with H2O2 in sunlit surface waters as well as in the treatment of organic pollutants in the advanced oxidation processes (AOPs). Concentrations of both H2O2 and Fe(2)(+)-DOM were dependent on time and total solar intensity flux, and their levels were highest in the diurnal samples collected at noon compared with the samples collected during the period before sunrise and after sunset. H2O2 and Fe(2)(+)-DOM concentrations during monthly readings were also found higher in comparison with the diurnal samples, shortly before sunrise or after sunset. A π-electron bonding system is formed between Fe and the functional groups in DOM (Fe-DOM), through electron donation from the functional groups of DOM to an empty d-orbital of Fe. The π-electron is loosely bound and is highly susceptible to a rapid excitation upon light exposure that will provide better understanding of the formation of aqueous electrons, superoxide radical anions, H2O2 and finally, photo-Fenton reactions, too. Our results imply that simultaneous generation of H2O2 and Fe(2)(+)-DOM upon sunlight exposure during the daytime is most likely to be the key photo-Fenton reaction pathway, taking place in surface waters. PMID:27593270

  9. A fluorescence turn on assay for alkaline phosphatase based on the Cu(2+) catalyzed Fenton-like reaction.

    Science.gov (United States)

    Zhang, Qingfeng; Zhang, Cuiyun; Shahzad, Sohail Anjum; Yu, Cong

    2016-09-01

    A fluorescence turn-on assay was established for ALP (alkaline phosphatase) based on Cu(2+) catalyzed Fenton-like reaction and Graphene Oxide (GO). GO was utilized to quench the fluorescence of fluorescein (FAM) labeled single strand DNA (F-DNA). ALP can remove the phosphate group in sodium ascorbyl phosphate (SAP), and convert it into reducing ascorbate. Highly reactive hydroxyl radicals (·OH) were generated in the presence of ascorbate and Cu(2+) through the Fenton-like reaction. The reactive radicals generated in situ caused the cleavage of F-DNA into small fragments. When GO was added, the fluorescence emission of the sample without ALP was quenched and fluorescence emission recovered in the presence of ALP. The intensity of the recovered fluorescence was directly related to the concentration of ALP in the assay solution, and a sensitive and selective facile ALP assay is therefore established. PMID:27343614

  10. Kinetic Analysis of Some Chalcones and Synthetic Chalcone Analogues on the Fenton-Reaction Initiated Deoxyribose Degradation Assay1

    OpenAIRE

    Perjési, Pál; Rozmer, Zsuzsanna

    2011-01-01

    Investigation of in vitro hydroxyl radical scavenging (antioxidant) effect 4-methoxychalcone (1a) and its cyclic analogues (2a-4a), as well as their hydroxyl substituted counterparts (1b-4b) was performed by means of the Fenton-reaction initiated deoxyribose degradation assay in short term (10 minute) and long term (240 minute) experiments. The kinetic deoxyribose method provides possibility to investigate not only the short term antioxidant (hydroxyl radical scavenger) effect but the possibl...

  11. Removal of trace metals and improvement of dredged sediment dewaterability by bioleaching combined with Fenton-like reaction.

    Science.gov (United States)

    Zeng, Xiangfeng; Twardowska, Irena; Wei, Shuhe; Sun, Lina; Wang, Jun; Zhu, Jianyu; Cai, Jianchao

    2015-05-15

    Bioleaching by Aspergillus niger strain SY1 combined with Fenton-like reaction was optimized to improve trace metal removal and dewaterability of dredged sediments. The major optimized parameters were the duration of bioleaching and H₂O₂ dose in Fenton-like process (5 days and 2g H₂O₂/L, respectively). Bioleaching resulted in the removal of ≈90% of Cd, ≈60% of Zn and Cu, ≈20% of Pb, and in decrease of sediment pH from 6.6 to 2.5 due to organic acids produced by A. niger. After addition of H₂O₂, Fenton-like reaction was initiated and further metal removal occurred. Overall efficiency of the combined process comprised: (i) reduction of Cd content in sediment by 99.5%, Cu and Zn by >70% and Pb by 39% as a result of metal release bound in all mobilizable fractions; (ii) decrease of sediment capillary suction time (CST) from 98.2s to 10.1s (by 89.8%) and specific resistance to filtration (SRF) from 37.4×10(12)m/kg to 6.2×10(12)m/kg (by 83.8%), due to reducing amount of extracellular polymeric substances (EPS) by 68.7% and bound water content by 79.1%. The combined process was found to be an efficient method to remove trace metals and improve dewaterability of contaminated dredged sediments. PMID:25682517

  12. Integrated treatment of olive mill wastewater (OMW) by the combination of Fenton's reaction and anaerobic treatment

    International Nuclear Information System (INIS)

    The use of an integrated treatment scheme consisting of wet hydrogen peroxide catalytic oxidation (WHPCO) followed by two-stage upflow anaerobic sludge blanket (UASB) reactor (10 l each) for the treatment of olive mill wastewater was the subject of this study. The diluted wastewater (1:1) was pre-treated using Fenton's reaction. Optimum operating conditions namely, pH, H2O2 dose, Fe+2, COD:H2O2 ratio and Fe+2:H2O2 ratio were determined. The UASB reactor was fed continuously with the pre-treated wastewater. The hydraulic retention time was kept constant at 48 h (24 h for each stage). The conventional parameters such as COD, BOD, TOC, TKN, TP, TSS, oil and grease, and total phenols were determined. The concentrations of polyphenolic compounds in raw wastewater and effluents of each treatment step were measured using HPLC. The results indicated a good quality final effluent. Residual concentrations of individual organic compounds ranged from 0.432 mg l-1 for ρ-hydroxy-benzaldhyde to 3.273 mg l-1 for cinnamic acid

  13. Ultradispersed Cobalt Ferrite Nanoparticles Assembled in Graphene Aerogel for Continuous Photo-Fenton Reaction and Enhanced Lithium Storage Performance

    Science.gov (United States)

    Qiu, Bocheng; Deng, Yuanxin; Du, Mengmeng; Xing, Mingyang; Zhang, Jinlong

    2016-07-01

    The Photo-Fenton reaction is an advanced technology to eliminate organic pollutants in environmental chemistry. Moreover, the conversion rate of Fe3+/Fe2+ and utilization rate of H2O2 are significant factors in Photo-Fenton reaction. In this work, we reported three dimensional (3D) hierarchical cobalt ferrite/graphene aerogels (CoFe2O4/GAs) composites by the in situ growing CoFe2O4 crystal seeds on the graphene oxide (GO) followed by the hydrothermal process. The resulting CoFe2O4/GAs composites demonstrated 3D hierarchical pore structure with mesopores (14~18 nm), macropores (50~125 nm), and a remarkable surface area (177.8 m2 g‑1). These properties endowed this hybrid with the high and recyclable Photo-Fenton activity for methyl orange pollutant degradation. More importantly, the CoFe2O4/GAs composites can keep high Photo-Fenton activity in a wide pH. Besides, the CoFe2O4/GAs composites also exhibited excellent cyclic performance and good rate capability. The 3D framework can not only effectively prevent the volume expansion and aggregation of CoFe2O4 nanoparticles during the charge/discharge processes for Lithium-ion batteries (LIBs), but also shorten lithium ions and electron diffusion length in 3D pathways. These results indicated a broaden application prospect of 3D-graphene based hybrids in wastewater treatment and energy storage.

  14. Ultradispersed Cobalt Ferrite Nanoparticles Assembled in Graphene Aerogel for Continuous Photo-Fenton Reaction and Enhanced Lithium Storage Performance

    Science.gov (United States)

    Qiu, Bocheng; Deng, Yuanxin; Du, Mengmeng; Xing, Mingyang; Zhang, Jinlong

    2016-01-01

    The Photo-Fenton reaction is an advanced technology to eliminate organic pollutants in environmental chemistry. Moreover, the conversion rate of Fe3+/Fe2+ and utilization rate of H2O2 are significant factors in Photo-Fenton reaction. In this work, we reported three dimensional (3D) hierarchical cobalt ferrite/graphene aerogels (CoFe2O4/GAs) composites by the in situ growing CoFe2O4 crystal seeds on the graphene oxide (GO) followed by the hydrothermal process. The resulting CoFe2O4/GAs composites demonstrated 3D hierarchical pore structure with mesopores (14~18 nm), macropores (50~125 nm), and a remarkable surface area (177.8 m2 g−1). These properties endowed this hybrid with the high and recyclable Photo-Fenton activity for methyl orange pollutant degradation. More importantly, the CoFe2O4/GAs composites can keep high Photo-Fenton activity in a wide pH. Besides, the CoFe2O4/GAs composites also exhibited excellent cyclic performance and good rate capability. The 3D framework can not only effectively prevent the volume expansion and aggregation of CoFe2O4 nanoparticles during the charge/discharge processes for Lithium-ion batteries (LIBs), but also shorten lithium ions and electron diffusion length in 3D pathways. These results indicated a broaden application prospect of 3D-graphene based hybrids in wastewater treatment and energy storage. PMID:27373343

  15. Iron and hydroxyl radicals in lipid oxidation: Fenton reactions in lipid and nucleic acids co-oxidized with lipid

    Energy Technology Data Exchange (ETDEWEB)

    Borg, D.C.; Schaich, K.M.

    1987-01-01

    Hydroxyl radicals can initiate lipid peroxidation in liquids, but their high reactivity affords reaction paths so short that they are unlikely to reach lipids in membrane bilayers when formed exteriorly. EPR studies of Fenton-like reactions inducing oxidation in bulk lipids indicate that iron-dependent initiation of lipid oxidation in organelles and vesicles may result from hydroxyl radicals formed within the hydrophobic membrane interiors, where they would be inaccessible to typical hydrophilic radical scavengers. The cytotoxic or cytogenetic results of lipid peroxidation, especially in nuclear membranes, may include radiominetic chemical damage to adjacent DNA or nucleoprotein. Preliminary product analyses of nucleic acid basis cooxidized with lipids in vitro support this view.

  16. Supported Nanosized α-FeOOH Improves Efficiency of Photoelectro-Fenton Process with Reaction-Controlled pH Adjustment for Sustainable Water Treatment

    Directory of Open Access Journals (Sweden)

    Chuan Wang

    2012-01-01

    Full Text Available The overall photoelectro-Fenton (PE-Fenton process for water treatment with neutral initial pH includes three steps of pH reduction, PE-Fenton reaction, and pH elevation. Reaction-controlled pH adjustment (RCpA, which utilizes the intrinsic electrochemical reactions instead of chemical addition, has been employed to lower the pH, maintain the lowered pH for the Fenton reaction, and recover the pH for final effluent discharge. This study demonstrated that the overall efficiency of this sustainable PE-Fenton process was improved by rapidly recycling the iron substance. Nanosized iron oxide was prepared and employed to ensure such rapid recycling. SEM and XRD results showed that the as-prepared iron oxide was α-FeOOH with 20 nm in size. The experimental results of dimethyl phthalate (DMP degradation showed that diatomite-supported α-FeOOH (N-α-FeOOH/diatomite could efficiently reduce the DMP concentration and total organic carbon. Furthermore, compared with Fe3+, the N-α-FeOOH/diatomite saved 160 min for iron settlement at 20 mg L−1 DMP concentration. Also, with the increment in the initial DMP concentration, extra energy consumed by the individual step of PE-Fenton reaction using the N-α-FeOOH/diatomite became negligible compared with that using free iron ions with the increment in the initial DMP concentration. This development is expected to be a major step of the PE-Fenton process with RCpA towards actual water treatment.

  17. Citric Acid-Modified Fenton's Reaction for the Oxidation of Chlorinated Ethylenes in Soil Solution Systems

    Energy Technology Data Exchange (ETDEWEB)

    Seol, Yongkoo; Javandel, Iraj

    2008-03-15

    Fenton's reagent, a solution of hydrogen peroxide and ferrous iron catalyst, is used for an in-situ chemical oxidation of organic contaminants. Sulfuric acid is commonly used to create an acidic condition needed for catalytic oxidation. Fenton's reaction often involves pressure buildup and precipitation of reaction products, which can cause safety hazards and diminish efficiency. We selected citric acid, a food-grade substance, as an acidifying agent to evaluate its efficiencies for organic contaminant removal in Fenton's reaction, and examined the impacts of using citric acid on the unwanted reaction products. A series of batch and column experiments were performed with varying H{sub 2}O{sub 2} concentrations to decompose selected chlorinated ethylenes. Either dissolved iron from soil or iron sulfate salt was added to provide the iron catalyst in the batch tests. Batch experiments revealed that both citric and sulfuric acid systems achieved over 90% contaminant removal rates, and the presence of iron catalyst was essential for effective decontamination. Batch tests with citric acid showed no signs of pressure accumulation and solid precipitations, however the results suggested that an excessive usage of H{sub 2}O{sub 2} relative to iron catalysts (Fe{sup 2+}/H{sub 2}O{sub 2} < 1/330) would result in lowering the efficiency of contaminant removal by iron chelations in the citric acid system. Column tests confirmed that citric acid could provide suitable acidic conditions to achieve higher than 55% contaminant removal rates.

  18. Degradation of Corn Oil Wastes by Fenton Reaction and Under Mildly Basic Media in the Presence of Oxidants Assisted with Sun Light

    Directory of Open Access Journals (Sweden)

    Josefina V.  Sanchez

    2008-01-01

    Full Text Available The degradation of water soluble corn oil wastes was carried out by Fenton reaction and also under mildly basic media in the presence of oxidants, such as hydrogen peroxide and persulfate, assisted with solar light. The degradation efficiency was obtained by analysis of chemical oxygen demand, carbon dioxide and gas chromatography. Over 90% of both chemical oxygen demand abatement and carbon dioxide recovery was accomplished by Fenton reaction. The presence of oxidants during the photodegradation resulted in high chemical oxygen demand abatement of the oil waste with the disappearance of the majority of the initial fatty acids present in the oil waste before treatment.

  19. Ex Vivo Antioxidant Activity of Selected Medicinal Plants against Fenton Reaction-Mediated Oxidation of Biological Lipid Substrates

    Directory of Open Access Journals (Sweden)

    Namratha Pai Kotebagilu

    2015-01-01

    Full Text Available Free radical-mediated oxidation is often linked to various degenerative diseases. Biological substrates with lipids as major components are susceptible to oxygen-derived lipid peroxidation due to their composition. Lipid peroxide products act as biomarkers in evaluating the antioxidant potential of various plants and functional foods. The study focused on evaluation of the antioxidant potential of two extracts (methanol and 80% methanol of four medicinal plants, Andrographis paniculata, Costus speciosus, Canthium parviflorum, and Abrus precatorius, against Fenton reaction-mediated oxidation of three biological lipid substrates; cholesterol, low-density lipoprotein, and brain homogenate. The antioxidant activity of the extracts was measured by thiobarbituric acid reactive substances method. Also, the correlation between the polyphenol, flavonoid content, and the antioxidant activity in biological substrates was analyzed. Results indicated highest antioxidant potential by 80% methanol extract of Canthium parviflorum (97.55%, methanol extract of Andrographis paniculata (72.15%, and methanol extract of Canthium parviflorum (49.55% in cholesterol, low-density lipoprotein, and brain, respectively. The polyphenol and flavonoid contents of methanol extract of Andrographis paniculata in cholesterol (r=0.816 and low-density lipoprotein (r=0.948 and Costus speciosus in brain (r=0.977, polyphenols, and r=0.949, flavonoids correlated well with the antioxidant activity. The findings prove the antioxidant potential of the selected medicinal plants against Fenton reaction in biological lipid substrates.

  20. Ex Vivo Antioxidant Activity of Selected Medicinal Plants against Fenton Reaction-Mediated Oxidation of Biological Lipid Substrates.

    Science.gov (United States)

    Pai Kotebagilu, Namratha; Reddy Palvai, Vanitha; Urooj, Asna

    2015-01-01

    Free radical-mediated oxidation is often linked to various degenerative diseases. Biological substrates with lipids as major components are susceptible to oxygen-derived lipid peroxidation due to their composition. Lipid peroxide products act as biomarkers in evaluating the antioxidant potential of various plants and functional foods. The study focused on evaluation of the antioxidant potential of two extracts (methanol and 80% methanol) of four medicinal plants, Andrographis paniculata, Costus speciosus, Canthium parviflorum, and Abrus precatorius, against Fenton reaction-mediated oxidation of three biological lipid substrates; cholesterol, low-density lipoprotein, and brain homogenate. The antioxidant activity of the extracts was measured by thiobarbituric acid reactive substances method. Also, the correlation between the polyphenol, flavonoid content, and the antioxidant activity in biological substrates was analyzed. Results indicated highest antioxidant potential by 80% methanol extract of Canthium parviflorum (97.55%), methanol extract of Andrographis paniculata (72.15%), and methanol extract of Canthium parviflorum (49.55%) in cholesterol, low-density lipoprotein, and brain, respectively. The polyphenol and flavonoid contents of methanol extract of Andrographis paniculata in cholesterol (r = 0.816) and low-density lipoprotein (r = 0.948) and Costus speciosus in brain (r = 0.977, polyphenols, and r = 0.949, flavonoids) correlated well with the antioxidant activity. The findings prove the antioxidant potential of the selected medicinal plants against Fenton reaction in biological lipid substrates. PMID:26933511

  1. Eco-friendly processing in enzymatic xylooligosaccharides production from corncob: Influence of pretreatment with sonocatalytic-synergistic Fenton reaction and its antioxidant potentials.

    Science.gov (United States)

    Kawee-Ai, Arthitaya; Srisuwun, Aungkana; Tantiwa, Nidtaya; Nontaman, Wimada; Boonchuay, Pinpanit; Kuntiya, Ampin; Chaiyaso, Thanongsak; Seesuriyachan, Phisit

    2016-07-01

    Delignification can be considered as a feasible process to pretreat lignocellulosic biomass in xylooligosaccharides production after the performance and efficiency has been improved through a few modifications. This study compared various pretreatment strategies such as Fenton, sonocatalytic, and sonocatalytic-synergistic Fenton employed on corncob in order to expose lignin content and saccharides to enhance the xylooligosaccharides yield by enzymatic hydrolysis. The dissolution of lignin and xylooligosaccharides production of corncob was enhanced by ultrasound assisted TiO2 and Fenton reaction. The corncob pretreated with a sonocatalytic-synergistic Fenton reaction gave the highest release of the lignin concentration level (1.03g/L), dissolution level (80.25%), and xylooligosaccharides content (46.45mg/g substrate). A two-step pretreatment processes consisting of the alkali treatment (pretreatment) and sonocatalytic-synergistic Fenton process (posttreatment) illustrated that subsequent enzymatic hydrolysis could be enhanced considerably. The release of the lignin concentration and xylooligosaccharides content were 33.20g/L and 174.81mg/g substrate, respectively. The antioxidant potential of xylooligosaccharides showed significant differences regarding the amount of xylooligosaccharides and the phenolic compounds produced. PMID:26964939

  2. Mn(2+)-mediated homogeneous Fenton-like reaction of Fe(III)-NTA complex for efficient degradation of organic contaminants under neutral conditions.

    Science.gov (United States)

    Li, Yifan; Sun, Jianhui; Sun, Sheng-Peng

    2016-08-01

    In this work, we report a novel Mn(2+)-mediated Fenton-like process based on Fe(III)-NTA complex that is super-efficient at circumneutral pH range. Kinetics experiments showed that the presence of Mn(2+) significantly enhanced the effectiveness of Fe(III)-NTA complex catalyzed Fenton-like reaction. The degradation rate constant of crotamiton (CRMT), a model compound, by the Fe(III)- NTA_Mn(2+) Fenton-like process was at least 1.6 orders of magnitude larger than that in the absence of Mn(2+). Other metal ions such as Ca(2+), Mg(2+), Co(2+) and Cu(2+) had no impacts or little inhibitory effect on the Fe(III)-NTA complex catalyzed Fenton-like reaction. The generation of hydroxyl radical (HO) and superoxide radical anion (O2(-)) in the Fe(III)-NTA_Mn(2+) Fenton-like process were suggested by radicals scavenging experiments. The degradation efficiency of CRMT was inhibited significantly (approximately 92%) by the addition of HO scavenger 2-propanol, while the addition of O2(-) scavenger chloroform resulted in 68% inhibition. Moreover, the results showed that other chelating agents such as EDTA- and s,s-EDDS-Fe(III) catalyzed Fenton-like reactions were also enhanced significantly by the presence of Mn(2+). The mechanism involves an enhanced generation of O2(-) from the reactions of Mn(2+)-chelates with H2O2, indirectly promoting the generation of HO by accelerating the reduction rate of Fe(III)-chelates to Fe(II)- chelates. PMID:27070388

  3. The decolorization of Acid Orange II in non-homogeneous Fenton reaction catalyzed by natural vanadium-titanium magnetite

    Energy Technology Data Exchange (ETDEWEB)

    Liang Xiaoliang; Zhong Yuanhong [Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 510640 (China); Graduate University of the Chinese Academy of Sciences, Beijing 100049 (China); Zhu Sanyuan; Zhu Jianxi; Yuan Peng [Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 510640 (China); He Hongping, E-mail: hehp@gig.ac.cn [Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 510640 (China); Zhang Jing [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)

    2010-09-15

    The catalytic activity of natural vanadium-titanium magnetite was investigated in the decolorization of Acid Orange II by non-homogeneous Fenton process. The natural catalysts purified by magnetic separation were characterized using X-ray diffraction (XRD), polarizing microscope, X-ray absorption fine structure (XAFS) analysis and Moessbauer spectroscopy. The obtained results show that the natural samples after magnetic separation mainly contain titanomagnetite, with a small amount of ilmenite and chlorite. Titanomagnetite is doped with vanadium, whose the valency is mainly +3 and occupies the octahedral site. Batch decolorization studies were performed to evaluate the influences of various experimental parameters like initial pH, the amount of catalyst and initial concentration of hydrogen peroxide on the decolorization efficiency of Acid Orange II. The decolorization of the dye mainly relied on degradation. The degradation efficiency was strongly dependent on pH of the medium where it increased as the pH decreased in acid range. The increase of catalyst and hydrogen peroxide could accelerate the degradation. The catalytic property of natural vanadium-titanium magnetite in the degradation of Acid Orange II was stronger than that of synthetic magnetite (Fe{sub 3}O{sub 4}). The catalytic activity of the natural samples was greatly related to the titanomagnetite content. The degradation process was dominated by heterogeneous Fenton reaction, complying with pseudo-first-order rate law. The natural catalyst has a good catalytic stability.

  4. The decolorization of Acid Orange II in non-homogeneous Fenton reaction catalyzed by natural vanadium-titanium magnetite

    International Nuclear Information System (INIS)

    The catalytic activity of natural vanadium-titanium magnetite was investigated in the decolorization of Acid Orange II by non-homogeneous Fenton process. The natural catalysts purified by magnetic separation were characterized using X-ray diffraction (XRD), polarizing microscope, X-ray absorption fine structure (XAFS) analysis and Moessbauer spectroscopy. The obtained results show that the natural samples after magnetic separation mainly contain titanomagnetite, with a small amount of ilmenite and chlorite. Titanomagnetite is doped with vanadium, whose the valency is mainly +3 and occupies the octahedral site. Batch decolorization studies were performed to evaluate the influences of various experimental parameters like initial pH, the amount of catalyst and initial concentration of hydrogen peroxide on the decolorization efficiency of Acid Orange II. The decolorization of the dye mainly relied on degradation. The degradation efficiency was strongly dependent on pH of the medium where it increased as the pH decreased in acid range. The increase of catalyst and hydrogen peroxide could accelerate the degradation. The catalytic property of natural vanadium-titanium magnetite in the degradation of Acid Orange II was stronger than that of synthetic magnetite (Fe3O4). The catalytic activity of the natural samples was greatly related to the titanomagnetite content. The degradation process was dominated by heterogeneous Fenton reaction, complying with pseudo-first-order rate law. The natural catalyst has a good catalytic stability.

  5. Combination of heterogeneous Fenton-like reaction and photocatalysis using Co-TiO2 nanocatalyst for activation of KHSO5 with visible light irradiation at ambient conditions

    Institute of Scientific and Technical Information of China (English)

    Qingkong Chen; Fangying Ji; Qian Guo; Jianping Fan; Xuan Xu

    2014-01-01

    A novel coupled system using Co-TiO2 was successfully designed which combined two different heterogeneous advanced oxidation processes,sulfate radical based Fenton-like reaction (SR-Fenton) and visible light photocatalysis (Vis-Photo),for degradation of organic contaminants.The synergistic effect of SR-Fenton and Vis-Photo was observed through comparative tests of 50 mg/L Rhodamine B (RhB) degradation and TOC removal.The Rhodamine B degradation rate and TOC removal were 100% and 68.1% using the SR-Fenton/Vis-Photo combined process under ambient conditions,respectively.Moreover,based on XRD,XPS and UV-DRS characterization,it can be deduced that tricobalt tetroxide located on the surface of the catalyst is the SR-Fenton active site,and cobalt ion implanted in the TiO2 lattice is the reason for the visible light photocatalytic activity of Co-TiO2.Finally,the effects of the calcination temperature and cobalt concentration on the synergistic performance were also investigated and a possible mechanism for the synergistic system was proposed.This coupled system exhibited excellent catalytic stability and reusability,and almost no dissolution of Co2+ was found.

  6. Hydrogenated Graphene as Metal-free Catalyst for Fenton-like Reaction

    Institute of Scientific and Technical Information of China (English)

    Yi Zhao; Wu-feng Chen; Cheng-fei Yuan; Zi-ye Zhu; Li-feng Yan

    2012-01-01

    Carbonaceous catalysts are potential alternatives to metal catalysts.Graphene has been paid much attention for its high surface area and light weight.Here,hydrogenated graphene has been prepared by a simple gamma ray irradiation of graphene oxide aqueous suspension at room temperature.Transmission electron microscopic,element analysis,X-ray photoelectron spectroscopy,and UV-Vis spectrophotometer studies verified the hydrogenation of graphene.The as-prepared hydrogenated graphene can be used as a metal-free carbonaceous catalyst for the Fenton-like degradation of organic dye in water.

  7. A Histone-Like Protein of Mycobacteria Possesses Ferritin Superfamily Protein-Like Activity and Protects against DNA Damage by Fenton Reaction

    OpenAIRE

    Takatsuka, Masaki; Osada-Oka, Mayuko; Satoh, Eisuke F.; Kitadokoro, Kengo; Nishiuchi, Yukiko; Niki, Mamiko; Inoue, Masayasu; Iwai, Kazuhiro; Arakawa, Tetsuo; SHIMOJI, Yoshihiro; Ogura, Hisashi; Kobayashi, Kazuo; Rambukkana, Anura; Matsumoto, Sohkichi

    2011-01-01

    Iron is an essential metal for living organisms but its level must be strictly controlled in cells, because ferrous ion induces toxicity by generating highly active reactive oxygen, hydroxyl radicals, through the Fenton reaction. In addition, ferric ion shows low solubility under physiological conditions. To overcome these obstacles living organisms possess Ferritin superfamily proteins that are distributed in all three domains of life: bacteria, archaea, and eukaryotes. These proteins minimi...

  8. Synergetic Effect of Ultrasound, the Heterogeneous Fenton Reaction and Photocatalysis by TiO2 Loaded on Nickel Foam on the Degradation of Pollutants

    Directory of Open Access Journals (Sweden)

    Shan Qiu

    2016-06-01

    Full Text Available The synergistic effect of ultrasound, the heterogeneous Fenton reaction and photocatalysis was studied using a nickel foam (NF-supporting TiO2 system and rhodamine B (RhB as a target. The NF-supporting TiO2 system was prepared by depositing TiO2 on the skeleton of NF repeatedly and then calcining it. To optimize the conditions and parameters, the catalytic activity was tested in four systems (ultrasound alone (US, nickel foam (NF, US/NF and NF/US/H2O2. The optimal conditions were fixed at 0.1 g/mL NF, initial 5.00 mg/L RhB, 300 W ultrasonic power, pH = 3 and 5.00 mg/L H2O2. The effects of the dissolution of nickel from NF and quenching of the Fenton reaction were studied on degradation efficiency. When the heterogeneous Fenton reaction is combined with TiO2-photocatalysis, the pollutant removal efficiency is enhanced significantly. Through this synergistic effect, 22% and 80% acetochlor was degraded within 10 min and 80 min, respectively.

  9. The contribution of vanadium and titanium on improving methylene blue decolorization through heterogeneous UV-Fenton reaction catalyzed by their co-doped magnetite

    International Nuclear Information System (INIS)

    Highlights: ► Ti-V co-doped magnetite has strong catalytic activity in UV-Fenton reaction. ► Ti4+ is more positive to adsorption and catalytic activity of magnetite than V3+. ► Mechanism of substitution increasing the adsorption and catalytic activity. ► The obtained results are benefit for application of magnetite in treating wastewater. - Abstract: This study investigated the methylene blue (MB) decolorization through heterogeneous UV-Fenton reaction catalyzed by V-Ti co-doped magnetites, with emphasis on comparing the contribution of V and Ti cations on improving the adsorption and catalytic activity of magnetite. In the well crystallized spinel structure, both Ti4+ and V3+ occupied the octahedral sites. Ti4+ showed a more obvious effect on increasing specific surface area and superficial hydroxyl amount than V3+ did, resulting in a significant improvement of the adsorption ability of magnetite to MB. The UV introduction greatly accelerated MB degradation. And magnetite with more Ti and less V displayed better catalytic activity in MB degradation through heterogeneous UV-Fenton reaction. The transformation of degradation products and individual contribution from vanadium and titanium on improving adsorption and catalytic activity of magnetite were also investigated. These new insights are of high importance for well understanding the interface interaction between contaminants and metal doped magnetites, and the environmental application of natural and synthetic magnetites.

  10. Effect and Cost Research for Leachate Treatment in PAC/Fenton and Fenton/PAC Technology

    Institute of Scientific and Technical Information of China (English)

    JIANG Bao-jun; YIN Jun; WU Xiao-yan; Zhao Yu-xin

    2010-01-01

    To compare the treatment effects and the costs of coagulation/Fenton process and Fenton/coagulation process in leachate treatment,fresh and old leachates were respestively treated with these two techniques.The experimental results indicate that the highest chemical oxygen demand(COD)removal rate of Fenton reaction on leachate can be acquired under the conditions of pH = 3.5,nH2O2/nFe2+= 6,mH2O2/mCOD = 3,and reaction time = 4 h.Polyaluminium chloride(PAC)coagulation has the highest COD removal rate on leachate under the condition of mPAC/mCOD = 0.6.Under the optimum reaction conditions,coagulation/Fenton and Fenton/coagulation processes were respestively adopted to treat raw leachate.The data also show that COD removal rate of coagulation/Fenton process on fresh and old leachates are90.56% and 86.52% respectively and that of Fenton/coagulation process 89.99% and 85.99%,so there is no obvious difference.But the cost of coagulation/Fenton process for leachate treatment is RMB 62.6,lower than that of Fenton/coagulation process.Therefore,coagulation/Fenton process is more optimized than Fenton/coagulation process for leachate treatment.

  11. Electrochemical detection of in situ DNA damage induced by enzyme-catalyzed Fenton reaction. Part I: In phosphate buffer solution

    International Nuclear Information System (INIS)

    We report on a biosensor for the electrochemical detection of the damage of DNA and of antioxidant protecting DNA. The biosensor was constructed by co-immobilization of DNA and glucose oxidase (GOx) on a glassy carbon electrode. Under aerobic conditions, GOx catalyzes the oxidation of glucose, and the hydrogen peroxide produced reacts with ferrous ions in a Fenton-type reaction to generate hydroxy radical. This was validated by UV-vis spectroscopy. The hydroxy radical can cause serious oxidative damage to DNA, and this can be detected by square wave voltammetry of the electroactive indicator Co(bpy)33+. The effects of pH value, incubation time, and the concentration of glucose and ferrous ion were optimized. The effects of the antioxidants ascorbic acid and aloe emodin on DNA damage were also investigated within the concentration range from 0.05 to 200 μM. This work provides an in-vitro model system to mimic the processes in oxidative DNA damage by a simple electrochemical approach. (author)

  12. Using Central Composite Experimental Design to Optimize the Degradation of Tylosin from Aqueous Solution by Photo-Fenton Reaction

    Directory of Open Access Journals (Sweden)

    Abd Elaziz Sarrai

    2016-05-01

    Full Text Available The feasibility of the application of the Photo-Fenton process in the treatment of aqueous solution contaminated by Tylosin antibiotic was evaluated. The Response Surface Methodology (RSM based on Central Composite Design (CCD was used to evaluate and optimize the effect of hydrogen peroxide, ferrous ion concentration and initial pH as independent variables on the total organic carbon (TOC removal as the response function. The interaction effects and optimal parameters were obtained by using MODDE software. The significance of the independent variables and their interactions was tested by means of analysis of variance (ANOVA with a 95% confidence level. Results show that the concentration of the ferrous ion and pH were the main parameters affecting TOC removal, while peroxide concentration had a slight effect on the reaction. The optimum operating conditions to achieve maximum TOC removal were determined. The model prediction for maximum TOC removal was compared to the experimental result at optimal operating conditions. A good agreement between the model prediction and experimental results confirms the soundness of the developed model.

  13. AN ADVANCED OXIDATION PROCESS : FENTON PROCESS

    Directory of Open Access Journals (Sweden)

    Engin GÜRTEKİN

    2008-03-01

    Full Text Available Biological wastewater treatment is not effective treatment method if raw wastewater contains toxic and refractory organics. Advanced oxidation processes are applied before or after biological treatment for the detoxification and reclamation of this kind of wastewaters. The advanced oxidation processes are based on the formation of powerful hydroxyl radicals. Among advanced oxidation processes Fenton process is one of the most promising methods. Because application of Fenton process is simple and cost effective and also reaction occurs in a short time period. Fenton process is applied for many different proposes. In this study, Fenton process was evaluated as an advanced oxidation process in wastewater treatment.

  14. Oxygen Reduction Reaction on Graphene in an Electro-Fenton System: In Situ Generation of H2 O2 for the Oxidation of Organic Compounds.

    Science.gov (United States)

    Chen, Chen-Yu; Tang, Cheng; Wang, Hao-Fan; Chen, Cheng-Meng; Zhang, Xiaoyuan; Huang, Xia; Zhang, Qiang

    2016-05-23

    Fenton oxidation using an aqueous mixture of Fe(2+) and H2 O2 is a promising environmental remediation strategy. However, the difficulty of storage and shipment of concentrated H2 O2 and the generation of iron sludge limit its broad application. Therefore, highly efficient and cost-effective electrocatalysts are in great need. Herein, a graphene catalyst is proposed for the electro-Fenton process, in which H2 O2 is generated in situ by the two-electron reduction of the dissolved O2 on the cathode and then decomposes to generate (.) OH in acidic solution with Fe(2+) . The π bond of the oxygen is broken whereas the σ bond is generally preserved on the metal-free reduced graphene oxide owing to the high free energy change. Consequently, the oxygen is reduced to H2 O2 through a two-electron pathway. The thermally reduced graphene with a high specific surface area (308.8 m(2)  g(-1) ) and a large oxygen content (10.3 at %) exhibits excellent reactivity for the two-electron oxygen reduction reaction to H2 O2 . A highly efficient peroxide yield (64.2 %) and a remarkable decolorization of methylene blue (12 mg L(-1) ) of over 97 % in 160 min are obtained. The degradation of methylene blue with hydroxyl radicals generated in situ is described by a pseudo first-order kinetics model. This provides a proof-of-concept of an environmentally friendly electro-Fenton process using graphene for the oxygen reduction reaction in an acidic solution to generate H2 O2 . PMID:27098063

  15. Fenton-like oxidation of small aromatic acids from biomass burning in atmospheric water and in the absence of light: Identification of intermediates and reaction pathways.

    Science.gov (United States)

    Santos, Patrícia S M; Domingues, M Rosário M; Duarte, Armando C

    2016-07-01

    A previous work showed that the night period is important for the occurrence of Fenton-like oxidation of small aromatic acids from biomass burning in atmospheric waters, which originate new chromophoric compounds apparently more complex than the precursors, although the chemical transformations involved in the process are still unknown. In this work were identified by gas chromatography-mass spectrometry (GC-MS) and by electrospray mass spectrometry (ESI-MS) the organic intermediate compounds formed during the Fenton-like oxidation of three aromatic acids from biomass burning (benzoic, 4-hydroxybenzoic and 3,5-dihydroxybenzoic acids), the same compounds evaluated in the previous study, in water and in the absence of light, which in turns allows to disclose the chemical reaction pathways involved. The oxidation intermediate compounds found for benzoic acid were 2-hydroxybenzoic, 3-hydroxybenzoic, 4-hydroxybenzoic, 2,3-dihydroxybenzoic, 2,5-dihydroxybenzoic, 2,6-dihydroxybenzoic and 3,4-dihydroxybenzoic acids. The oxidation intermediates for 4-hydroxybenzoic acid were 3,4-hydroxybenzoic acid and hydroquinone, while for 3,5-dihydroxybenzoic acid were 2,4,6-trihydroxybenzoic and 3,4,5-trihydroxybenzoic acids, and tetrahydroxybenzene. The results suggested that the hydroxylation of the three small aromatic acids is the main step of Fenton-like oxidation in atmospheric waters during the night, and that the occurrence of decarboxylation is also an important step during the oxidation of the 4-dihydroxybenzoic and 3,5-dihydroxybenzoic acids. In addition, it is important to highlight that the compounds produced are also small aromatic compounds with potential adverse effects on the environment, besides becoming available for further chemical reactions in atmospheric waters. PMID:27088537

  16. A histone-like protein of mycobacteria possesses ferritin superfamily protein-like activity and protects against DNA damage by Fenton reaction.

    Science.gov (United States)

    Takatsuka, Masaki; Osada-Oka, Mayuko; Satoh, Eisuke F; Kitadokoro, Kengo; Nishiuchi, Yukiko; Niki, Mamiko; Inoue, Masayasu; Iwai, Kazuhiro; Arakawa, Tetsuo; Shimoji, Yoshihiro; Ogura, Hisashi; Kobayashi, Kazuo; Rambukkana, Anura; Matsumoto, Sohkichi

    2011-01-01

    Iron is an essential metal for living organisms but its level must be strictly controlled in cells, because ferrous ion induces toxicity by generating highly active reactive oxygen, hydroxyl radicals, through the Fenton reaction. In addition, ferric ion shows low solubility under physiological conditions. To overcome these obstacles living organisms possess Ferritin superfamily proteins that are distributed in all three domains of life: bacteria, archaea, and eukaryotes. These proteins minimize hydroxyl radical formation by ferroxidase activity that converts Fe(2+) into Fe(3+) and sequesters iron by storing it as a mineral inside a protein cage. In this study, we discovered that mycobacterial DNA-binding protein 1 (MDP1), a histone-like protein, has similar activity to ferritin superfamily proteins. MDP1 prevented the Fenton reaction and protects DNA by the ferroxidase activity. The K(m) values of the ferroxidase activity by MDP1 of Mycobacterium bovis bacillus Calmette-Guérin (BCG-3007c), Mycobacterium tuberculosis (Rv2986c), and Mycobacterium leprae (ML1683; ML-LBP) were 0.292, 0.252, and 0.129 mM, respectively. Furthermore, one MDP1 molecule directly captured 81.4±19.1 iron atoms, suggesting the role of this protein in iron storage. This study describes for the first time a ferroxidase-iron storage protein outside of the ferritin superfamily proteins and the protective role of this bacterial protein from DNA damage. PMID:21698192

  17. SIMULTANEOUS DEGRADATION OF SOME PHTHALATE ESTERS UNDER FENTON AND PHOTO-FENTON OXIDATION PROCESSES

    OpenAIRE

    BELDEAN-GALEA M.S.; COZMA A.M.; DIODIU R.

    2015-01-01

    In this study the assessment of the degradation efficiency of five phthalates, DEP, BBP, DEHP, DINP and DIDP, found in a mixture in a liquid phase, using the Fenton and Photo Fenton oxidation processes, was conducted. It was observed that the main parameters that influence the Fenton oxidative processes of phthalates were the concentration of the oxidizing agent, H2O2, the concentration of the catalyst used, Fe2+, the pH value, UV irradiation and the reaction time. For the Fenton oxidative pr...

  18. Treating leachate by Fenton oxidation

    Directory of Open Access Journals (Sweden)

    Roger Iván Méndez Novelo

    2010-05-01

    Full Text Available Leachates are formed from liquids, mainly rainwater, percolating through solid wastes during stabilisation. Their composition is variable and highly toxic; leachate treatment is therefore a complex task. Leachates represent a high risk to health due to the Yucatan Peninsula’s highly permeable soil. The results are presented from applying the Fenton process to treating leachate from the sanitary Merida landfill, Yucatan, Mexico. The Fenton process consists of treating the contaminant load with an H2O2 and FeSO4 combination in acidic conditions. Optimal reaction time, pH value, Fenton reagent dose, post treatment coagulation – flocculation doses and increased biodegradability index were all determined. Optimal oxidation conditions and doses were 202+ minute contact time, 4 pH, 600 mg/L H2O2 concentration and 1,000 mg/L Fe. Average organic matter removal rate, measured as CODS and TOC, were 78% and 87% respectively. The biodegradability index increased from 0.07 to 0.11 during the Fenton process and up to 0.13 when the Fenton process was followed by coagulation-flocculation.

  19. Degradation of the azo dye Acid Red 1 by anodic oxidation and indirect electrochemical processes based on Fenton's reaction chemistry. Relationship between decolorization, mineralization and products

    International Nuclear Information System (INIS)

    Highlights: • Degradation of Acid Red 1 by anodic oxidation, electro-Fenton and photoelectro-Fenton • Quicker and similar decolorization by electro-Fenton and photoelectro-Fenton due to oxidation with ●OH in the bulk • Almost total mineralization by photoelectro-Fenton with Pt or BDD due to fast photolysis of products by UVA light • Detection of 11 aromatic products, 15 hydroxylated compounds, 13 desulfonated derivatives and 7 carboxylic acids • Release of NH4+, NO3− and SO42− ions, and generation of persistent N-products of low molecular mass - Abstract: Solutions of 236 mg dm−3 Acid Red 1 (AR1), an azo dye widely used in textile dying industries, at pH 3.0 have been comparatively treated by anodic oxidation with electrogenerated H2O2 (AO-H2O2), electro-Fenton (EF) and photoelectro-Fenton (PEF) at constant current density (j). Assays were performed with a stirred tank reactor equipped with a Pt or boron-doped diamond (BDD) anode and an air-diffusion cathode for H2O2 generation from O2 reduction. The main oxidizing agents were hydroxyl radicals produced at the anode from water oxidation in all methods and in the bulk from Fenton's reaction between generated H2O2 and 0.5 mmol dm−3 Fe2+ in EF and PEF. For each anode, higher oxidation power was found in the sequence AO-H2O2 < EF < PEF. The oxidation ability of the BDD anode was always superior to that of Pt. Faster and similar decolorization efficiency was achieved in EF and PEF owing to the quicker destruction of aromatics with hydroxyl radicals produced in the bulk. The PEF process with BDD was the most potent method yielding almost total mineralization due to the additional rapid photolysis of recalcitrant intermediates like Fe(III)-carboxylate complexes under UVA irradiation. The increase in j always enhanced the decolorization and mineralization processes because of the greater production of hydroxyl radicals, but decreases the mineralization current efficiency. A total of 11 aromatic

  20. Electrochemical detection of in situ DNA damage induced by enzyme-catalyzed Fenton reaction. Part II in hydrophobic room temperature ionic liquid

    International Nuclear Information System (INIS)

    A hydrophobic room temperature ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]), was applied as nonaqueous solvent for the generation of hydroxy radical (.OH) through glucose oxidase-catalyzed Fenton reaction. The enzyme catalyzes the oxidation of glucose, and the produced H2O2 further reacts with transition metal ions, generating hydroxyl radicals. They attacked DNA and led its damage. This was detected by square wave voltammetry (SWV) of the electroactive indicator Co(bpy)33+. It bound more strongly to intact DNA, and the SWV peak currents decreased at the potential of 0.064 V when DNA was damaged. The experimental results testified that the antioxidants, ascorbic acid, aloe-emodin and rutin, inhibited oxidative DNA damage by hydroxyl radicals. The method is promising for rapid, sensitive, and inexpensive detection of DNA damage. (author)

  1. Alkydic resin wastewaters treatment by fenton and photo-Fenton processes

    International Nuclear Information System (INIS)

    Advanced oxidation processes are an emerging option to treatment of the painting industry effluents. The aim of this study was to compare the effectiveness of the Fenton and photo-Fenton processes in chemical oxygen demand (COD), total organic carbon (TOC) and phenolic compounds removal from wastewaters generated during alkydic resins manufacture. The optimized treatment conditions are the following: pH 3.0, 15.15 x 10-3 mol L-1 FeSO4 and 0.30 mol L-1 H2O2 for a reaction time of 6 h. photo-Fenton experiments were carried out in the presence of sunlight or artificial radiation and complementary additions of H2O2 were made for all experiments. The best results were obtained with photo-Fenton process assisted with solar radiation, with reductions of 99.5 and 99.1% of COD and TOC levels, respectively. Fenton and photo-Fenton (with artificial irradiation) processes presented lower but not insignificant removals, within 60-80% reduction for both COD and TOC. In addition, an excellent removal (95%) of total phenols was obtained using photo-Fenton process assisted with artificial irradiation. This study demonstrated that the use of photo-Fenton process on alkydic resins wastewater treatment is very promising especially when solar light is used

  2. Rapid and facile preparation of zinc ferrite (ZnFe{sub 2}O{sub 4}) oxide by microwave-solvothermal technique and its catalytic activity in heterogeneous photo-Fenton reaction

    Energy Technology Data Exchange (ETDEWEB)

    Anchieta, Chayene G.; Severo, Eric C.; Rigo, Caroline; Mazutti, Marcio A. [Department of Chemical Engineering, Federal University of Santa Maria, 97105-900, Santa Maria (Brazil); Kuhn, Raquel C., E-mail: raquelckuhn@yahoo.com.br [Department of Chemical Engineering, Federal University of Santa Maria, 97105-900, Santa Maria (Brazil); Muller, Edson I.; Flores, Erico M.M. [Department of Chemistry, Federal University of Santa Maria, 97105-900, Santa Maria (Brazil); Moreira, Regina F.P.M. [Department of Chemical Engineering and Food Engineering, Federal University of Santa Catarina, 88040-970, Florianópolis (Brazil); Foletto, Edson L. [Department of Chemical Engineering, Federal University of Santa Maria, 97105-900, Santa Maria (Brazil)

    2015-06-15

    In this work zinc ferrite (ZnFe{sub 2}O{sub 4}) oxide was rapidly and easily prepared by microwave-solvothermal route and its catalytic property in photo-Fenton reaction was evaluated. The effects of microwave heating time and power on the properties of produced particles were investigated. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM) and nitrogen adsorption–desorption isotherms were the techniques used for characterizing the solid products. The synthesized material was tested as a catalyst in the degradation of the textile dye molecule by the heterogeneous photo-Fenton process. Characterization results showed that the microwave heating time and power have significant influences on the formation of the phase spinel as well as on its physical properties. The reaction results showed that the ZnFe{sub 2}O{sub 4} oxide has good photocatalytic activity, which can be attributed to high surface area and pore volume, and large pore size. The ZnFe{sub 2}O{sub 4} oxide produced by the microwave irradiation exhibited promising photocatalytic activity for the removal of textile dye, reaching nearly 100% of decolorization at 40 min and 60% of mineralization at 240 min. Therefore, ZnFe{sub 2}O{sub 4} particles rapidly prepared by the microwave route have the potential for use in treatment of textile wastewater by the heterogeneous photo-Fenton process. - Highlights: • ZnFe{sub 2}O{sub 4} was synthesized by microwave-solvothermal method. • ZnFe{sub 2}O{sub 4} was prepared by different microwave heating times and powers. • ZnFe{sub 2}O{sub 4} was used as heterogeneous photo-Fenton catalyst. • Degradation of Procion red dye using heterogeneous photo-Fenton process. • ZnFe{sub 2}O{sub 4} was highly efficient to degrade textile dye under visible light.

  3. Rapid and facile preparation of zinc ferrite (ZnFe2O4) oxide by microwave-solvothermal technique and its catalytic activity in heterogeneous photo-Fenton reaction

    International Nuclear Information System (INIS)

    In this work zinc ferrite (ZnFe2O4) oxide was rapidly and easily prepared by microwave-solvothermal route and its catalytic property in photo-Fenton reaction was evaluated. The effects of microwave heating time and power on the properties of produced particles were investigated. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM) and nitrogen adsorption–desorption isotherms were the techniques used for characterizing the solid products. The synthesized material was tested as a catalyst in the degradation of the textile dye molecule by the heterogeneous photo-Fenton process. Characterization results showed that the microwave heating time and power have significant influences on the formation of the phase spinel as well as on its physical properties. The reaction results showed that the ZnFe2O4 oxide has good photocatalytic activity, which can be attributed to high surface area and pore volume, and large pore size. The ZnFe2O4 oxide produced by the microwave irradiation exhibited promising photocatalytic activity for the removal of textile dye, reaching nearly 100% of decolorization at 40 min and 60% of mineralization at 240 min. Therefore, ZnFe2O4 particles rapidly prepared by the microwave route have the potential for use in treatment of textile wastewater by the heterogeneous photo-Fenton process. - Highlights: • ZnFe2O4 was synthesized by microwave-solvothermal method. • ZnFe2O4 was prepared by different microwave heating times and powers. • ZnFe2O4 was used as heterogeneous photo-Fenton catalyst. • Degradation of Procion red dye using heterogeneous photo-Fenton process. • ZnFe2O4 was highly efficient to degrade textile dye under visible light

  4. Fenton's reagent as a remediation process in water treatment: application to the degradation of polycyclic aromatic hydrocarbons in waters and sewage sludges; La reaction de fenton comme procede de rehabilitation dans le traitement des eaux: application a la degradation des hydrocarbures aromatiques polycycliques dans les eaux et les boues residuaires

    Energy Technology Data Exchange (ETDEWEB)

    Flotron, V.

    2004-05-15

    This study is related to the application of Fenton's reagent to remedy matrices contaminated by polycyclic aromatic hydrocarbons (PAHs). In aqueous solution, the choice of the reagent implementation is important, in order to generate enough radicals to oxidize pollutants. Degradation of the organic compounds is possible, but a large difference in reactivity is observed between 'alternant' and 'non-alternant' PAHs (with a five carbon atoms cycle). Besides, if a few specific precautions are omitted, the PAHs can sorb onto the flask inside surface, and therefore not undergo oxidation. The results on sewage sludges show that under certain conditions (high reagent concentrations), the pollutants can be oxidised although they are adsorbed. Moreover, it appears that the matrix itself plays an important role, as the iron oxides seem to be able to decompose hydrogen peroxide, and thus initiate Fenton reaction. Its application to contaminated soils and sediments is also possible. (author)

  5. Experimental Design of Photo-Fenton Reactions for the Treatment of Car Wash Wastewater Effluents by Response Surface Methodological Analysis

    Directory of Open Access Journals (Sweden)

    Maha A. Tony

    2014-01-01

    Full Text Available Establishing a treatment process for practical and economic disposal of car wash wastewater has become an urgent environmental concern. Photo-Fenton’s process as one of the advanced oxidation processes is a potentially useful oxidation process in treating such wastewater. Lab-scale experiments with UV source, coupled with Fenton’s reagent, showed that hydrocarbon oil is degradable through such a process. The feasibility of photo-Fenton’s process to treat wastewater from a car wash is investigated in the present study. A factorial design based on the response surface methodology was applied to optimize the photo-Fenton oxidation process conditions using chemical oxygen demand (COD reduction as the target parameter to optimize. The reagent (Fe2+ and H2O2 concentration and pH are used as the controlling factors to be optimized. Maximal COD reduction (91.7% was achieved when wastewater samples were treated at pH 3.5 in the presence of hydrogen peroxide and iron in amounts of 403.9 and 48.4 mg/L, respectively.

  6. Evidence against hydroxyl radical mechanism in photo-Fenton degradation of p-chlorophenol

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    This paper provides evidence for the degradation of organic pollutant by the photo-Fenton complex mechanism. Both the tum yield. The hydroxyl radical involved in the photo-Fenton process can also be generated from the decomposition of H2O2,photolysis of Fe3+ and degradation of hydrated Fe(Ⅵ)-complex, excepting the traditional Fenton reaction.

  7. Sulfate radicals induced from peroxymonosulfate by cobalt manganese oxides (CoxMn3−xO4) for Fenton-Like reaction in water

    International Nuclear Information System (INIS)

    Highlights: • A series of CoxMn3−xO4 particles as Fenton-like solid catalysts were synthesized. • CoMn2O4/PMS exhibits high activity due to synergistic effects of Co and Mn species. • Reaction conditions and degradation mechanism have been analyzed. • Contributions from SO4·− and HO· radicals to the reaction were measured using scavengers. • The catalyst had good stability and reusability during the five successive runs. - Abstract: A series of CoxMn3−xO4 particles as Fenton-like solid catalysts were synthesized, and their catalytic performance in oxidative degradation of organic dye compounds in water was investigated. The surface morphology and structure of the CoxMn3−xO4 catalysts were characterized by field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), powder X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The results showed that, as an oxide composite of Co and Mn elements, CoMn2O4 showed much stronger catalytic activity in peroxymonosulfate (PMS) oxidation than Co3O4, Mn2O3, and their physical mixture. Typically, the uses of 0.02 g/dm3 CoMn2O4 and 0.2 g/dm3 PMS yielded a nearly complete removal of Rhodamine B (0.03 g/dm3) in 80 min at 25 °C. The efficiency of Rhodamine B decomposition increased with increasing temperature (15–55 °C), but decreased with the increase of fulvic acid concentration (0–0.08 g/dm3). Furthermore, CoMn2O4 could maintain its catalytic activity in the repeated batch experiments. Moreover, HO· and SO4·− radicals participating in the process were evidenced using quenching experiments, and a rational mechanism was proposed. PMS oxidation with CoMn2O4 is an efficient technique for remediation of organic contaminants in wastewater

  8. Advanced Treatment of Pesticide-Containing Wastewater Using Fenton Reagent Enhanced by Microwave Electrodeless Ultraviolet

    OpenAIRE

    Gong Cheng; Jing Lin; Jian Lu; Xi Zhao; Zhengqing Cai; Jie Fu

    2015-01-01

    The photo-Fenton reaction is a promising method to treat organic contaminants in water. In this paper, a Fenton reagent enhanced by microwave electrodeless ultraviolet (MWEUV/Fenton) method was proposed for advanced treatment of nonbiodegradable organic substance in pesticide-containing biotreated wastewater. MWEUV lamp was found to be more effective for chemical oxygen demand (COD) removal than commercial mercury lamps in the Fenton process. The pseudo-first order kinetic model can well desc...

  9. Genotoxicity assessment of membrane concentrates of landfill leachate treated with Fenton reagent and UV-Fenton reagent using human hepatoma cell line.

    Science.gov (United States)

    Wang, Guifang; Lu, Gang; Yin, Pinghe; Zhao, Ling; Yu, Qiming Jimmy

    2016-04-15

    Membrane concentrates of landfill leachates contain organic and inorganic contaminants that could be highly toxic and carcinogenic. In this paper, the genotoxicity of membrane concentrates before and after Fenton and UV-Fenton reagent was assessed. The cytotoxicity and genotoxicity was determined by using the methods of methyltetrazolium (MTT), cytokinesis-block micronucleus (CBMN) and comet assay in human hepatoma cells. MTT assay showed a cytotoxicity of 75% after 24h of exposure to the highest tested concentration of untreated concentrates, and no cytotoxocity for UV-Fenton and Fenton treated concentrates. Both CBMN and comet assays showed increased levels of genotoxicity in cells exposed to untreated concentrates, compared to those occurred in cells exposed to UV-Fenton and Fenton reagent treated concentrates. There was no significant difference between negative control and UV-Fenton treated concentrates for micronucleus and comet assay parameters. UV-Fenton and Fenton treatment, especially the former, were effective methods for degradation of bisphenol A and nonylphenol in concentrates. These findings showed UV-Fenton and Fenton reaction were effective methods for treatment of such complex concentrates, UV-Fenton reagent provided toxicological safety of the treated effluent, and the genotoxicity assays were found to be feasible tools for assessment of toxicity risks of complex concentrates. PMID:26780702

  10. SIMULTANEOUS DEGRADATION OF SOME PHTHALATE ESTERS UNDER FENTON AND PHOTO-FENTON OXIDATION PROCESSES

    Directory of Open Access Journals (Sweden)

    BELDEAN-GALEA M.S.

    2015-03-01

    Full Text Available In this study the assessment of the degradation efficiency of five phthalates, DEP, BBP, DEHP, DINP and DIDP, found in a mixture in a liquid phase, using the Fenton and Photo Fenton oxidation processes, was conducted. It was observed that the main parameters that influence the Fenton oxidative processes of phthalates were the concentration of the oxidizing agent, H2O2, the concentration of the catalyst used, Fe2+, the pH value, UV irradiation and the reaction time. For the Fenton oxidative process, the highest degradation efficiencies were 19% for DEP, 50% for BBP, 84% for DEHP, 90% for DINP and 48% for DIDP, when the experiments were carried out using concentrations of 20 mg L-1 phthalate mixture, 100 mg L-1 H2O2, 10 mg L-1 Fe2+ at a pH value of 3, with a total reaction time of 30 minutes. For the Photo-Fenton oxidative process carried out in the same conditions as Fenton oxidative process, it was observed that after an irradiation time of 90 minutes under UV radiation the degradation efficiencies of phthalates were improved, being 22% for DEP, 71% for BBP, 97% for DEHP, 97% for DINP and 81% for DIDP.

  11. Graphene quantum dots from a facile sono-Fenton reaction and its hybrid with a polythiophene graft copolymer toward photovoltaic application.

    Science.gov (United States)

    Routh, Parimal; Das, Sandip; Shit, Arnab; Bairi, Partha; Das, Pradip; Nandi, Arun K

    2013-12-11

    A new and facile approach for synthesizing graphene quantum dots (GQDs) using sono-Fenton reaction in an aqueous dispersion of graphene oxide (GO) is reported. The transmission electron microscopy (TEM) micrographs of GQDs indicate its average diameter as ∼5.6 ± 1.4 nm having a lattice parameter of 0.24 nm. GQDs are used to fabricate composites (PG) with a water-soluble polymer, polythiophene-g-poly[(diethylene glycol methyl ether methacrylate)-co-poly(N,N-dimethylaminoethyl methacrylate)] [PT-g-P(MeO2MA-co-DMAEMA), P]. TEM micrographs indicate that both P and PG possess distinct core-shell morphology and the average particle size of P (0.16 ± 0.08 μm) increases in PG (0.95 ± 0.45 μm). Fourier transform infrared and X-ray photoelectron spectrometry spectra suggest an interaction between -OH and -COOH groups of GQDs and -NMe2 groups of P. A decrease of the intensity ratio of Raman D and G bands (ID/IG) is noticed during GQD and PG formation. In contrast to GO, GQDs do not exhibit any absorption peak for its smaller-sized sp(2) domain, and in PG, the π-π* absorption of polythiophene (430 nm) of P disappears. The photoluminescence (PL) peak of GQD shifts from 450 to 580 nm upon a change in excitation from 270 to 540 nm. PL emission of PG at 537 nm is quenched, and it shifts toward lower wavelength (∼430 nm) with increasing aging time for energy transfer from P to GQDs followed by up-converted emission of GQDs. Both P and PG exhibit semiconducting behavior, and PG produces an almost reproducible photocurrent. Dye-sensitized solar cells (DSSCs) fabricated with an indium-titanium oxide/PG/graphite device using the N719 dye exhibit a short-circuit current (Jsc) of 4.36 mA/cm(2), an open-circuit voltage (Voc) of 0.78 V, a fill factor of 0.52, and a power conversion efficiency (PCE, η) of 1.76%. Extending the use of GQDs to fabricate DSSCs with polypyrrole, both Voc and Jsc increase with increasing GQD concentration, showing a maximum PCE of 2.09%. The PG

  12. Degradation of flumequine by the Fenton and photo-Fenton processes: Evaluation of residual antimicrobial activity

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues-Silva, Caio; Maniero, Milena Guedes [School of Civil Engineering, Architecture and Urbanism, University of Campinas — UNICAMP, P.O. Box 6021, CEP 13083-852, Campinas, SP (Brazil); Rath, Susanne [Chemistry Institute, University of Campinas — UNICAMP, P.O. Box 6154, CEP 13084-971, Campinas, SP (Brazil); Guimarães, José Roberto, E-mail: jorober@fec.unicamp.br [School of Civil Engineering, Architecture and Urbanism, University of Campinas — UNICAMP, P.O. Box 6021, CEP 13083-852, Campinas, SP (Brazil)

    2013-02-15

    Flumequine is a broad-spectrum antimicrobial agent of the quinolone class, and it is widely used as a veterinary drug in food-producing animals. The presence of flumequine in the environment may contribute to the development of drug resistant bacterial strains. In this study, water samples fortified with flumequine (500 μg L{sup −1}) were degraded using the Fenton and photo-Fenton processes. The maximum degradation efficiency for flumequine by the Fenton process was approximately 40% (0.5 mmol L{sup −1} Fe(II), 2.0 mmol L{sup −1} H{sub 2}O{sub 2} and 15 min). By applying UV radiation (photo-Fenton process), the efficiency reached more than 94% in 60 min when 0.25 mmol L{sup −1} Fe(II) and 10.0 mmol L{sup −1} H{sub 2}O{sub 2} were used. Under these conditions, the Fenton process was able to reduce the biological activity, whereas the photo-Fenton process eliminated almost all of the antimicrobial activity because it was not detected. Four byproducts with an m/z of 244, 238, 220 and 202 were identified by mass spectrometry, and a degradation pathway for flumequine was proposed. The byproducts were derived from decarboxylation and defluorination reactions and from modifications in the alkylamino chain of the fluoroquinolone. - Highlights: ► Photo-Fenton process achieved the maximum performance, degrading 94% of flumequine. ► As the flumequine concentration decreased, antimicrobial activity also decreased. ► Four byproducts with m/z of 244, 238, 220 and 202 were identified. ► A degradation pathway for flumequine was proposed.

  13. Removal of Textile Dyes from Aqueous Solution by Heterogeneous Photo-Fenton Reaction Using Modified PAN Nanofiber Fe Complex as Catalyst

    OpenAIRE

    Xueting Zhao; Yongchun Dong; Bowen Cheng; Weimin Kang

    2013-01-01

    The modified PAN nanofiber Fe complex was prepared by the amidoximation and Fe coordination of PAN nanofiber was obtained using electrospinning technique and then used for the heterogeneous Fenton degradation of textile dyes as a novel catalyst. Some main factors affecting dye degradation such as Fe content of catalyst, irradiation intensity, H2O2 initial concentration, the solution pH as well as dye structure, and initial concentration were investigated. UV-Vis spectrum analysis and TOC meas...

  14. Evaluation of Efficacy of Advanced Oxidation Processes Fenton, Fenton-like and Photo-Fenton for Removal of Phenol from Aqueous Solutions

    International Nuclear Information System (INIS)

    Contamination of water, soil and groundwater caused by aromatic compounds induces great concern in most world areas. Among organic pollutants, phenol is mostly considered dangerous due to its high toxicity for human and animal. Advanced oxidation processes (AOPs) is considered as a most efficient method also the best one for purifying organic compounds which are resistant to conventional physical and chemical processes. This experimental study was carried out in laboratory scale. First, a synthetic solution was made of phenol. Then, Fenton, Fenton-like and photo-Fenton processes were applied removing phenol from aquatic solution. The effects of Hydrogen Peroxide concentration, catalyst, pH and time were studied to phenol removal efficiency. Results showed that Photo-Fenton process with removal efficiency (97.5 percentage) is more efficient than Fenton and Fenton-like processes with removal efficiency (78.7 percentage and 82.5 percentage respectively), in pH=3, (H/sub 2/O/sub 2/)= 3mM, (Fe2+)= 0.1 mM, phenol concentration 100 mg L-1 and time reaction 60 min, the phenol removal was 97.5 percentage. (author)

  15. Comparative analysis of trace contaminants in leachates before and after a pre-oxidation using a solar photo-Fenton reaction.

    Science.gov (United States)

    Rocha, Elisangela M R; Mota, Francisco S; Vilar, Vítor J P; Boaventura, Rui A R

    2013-09-01

    Sanitary landfill leachates are a complex mixture of high-strength organic and inorganic persistent contaminants, which constitute a serious environmental problem. In this study, trace contaminants present in leachates were investigated by gas chromatography-mass spectrometry and gas chromatography-flame ionization detector before and after a pre-oxidation step using a solar photo-Fenton process. More than 40 organic compounds were detected and identified as benzene (0.09 ± 0.07 mg L(-1)), trichlorophenol (TCP) (0.18 ± 0.12 mg L(-1)), phthalate esters (Di-n-butyl phthalate (DBP), Butyl benzyl phthalate (BBP), Di(2-ethylhexyl) phthalate (DEHP)) (DBP: 0.47 ± 0.01 mg L(-1); BBP: 0.36 ± 0.02 mg L(-1); DEHP: 0.18 ± 0.01 mg L(-1)), among others. Toluene, pentachlorophenol, dimethyl phthalate, diethyl phthalate, and Di-n-octyl phthalate were never detected in any of the samples. After the photo-Fenton treatment process, TCP decreased to levels below its detection limit, benzene concentration increased approximately three times, and DBP concentration decreased about 77 % comparatively to the raw leachate sample. The solar photo-Fenton process was considered to be very efficient for the treatment of sanitary landfill leachates, leading to the complete elimination of 24 of the detected micropollutants to levels below their respective detection limits and low to significant abatement of seven other organic compounds, thus resulting in an increase of the leachate biodegradability. PMID:23519479

  16. Effect of Particles on Fenton Oxidation of Organic Contaminated Groundwater

    Science.gov (United States)

    Lee, J.; Kim, Y.; Gwak, J.; Lee, C.; Ha, J.

    2009-12-01

    Fenton oxidation has been widely applied for a variety of water treatment due to non-selectively oxidative capability at a high reaction rate and cost effectiveness. Even though wide and deep range of studies were conducted for understanding the Fenton reaction with various contaminants, effect of particles on Fenton reaction has been little studied. This study explored the performance of Fenton oxidation for organic contaminated groundwater treatment in the presence of particles. The contaminated groundwater was a free oil separated groundwater obtained from a pilot scale bioslurping process for LNAPL treatment. The groundwater was characterized by a high suspended solid (SS) concentration relative to total organic carbon (TOC) concentration varying from 4 to 7.3. It was found that the optimum ratio of Fenton’s reagent (Fe2+:H2O2) was 1:10 in terms of TOC removal efficiency. Presence of solid particles significantly affected the TOC removal efficiency by Fenton’s reaction accounting for 37% for raw groundwater and 61% for soluble groundwater. Particles larger than 5 µm could be effectively settled out by a quiescent settling for 3 hr based on particle size distribution analysis. The TOC removal efficiency for the supernatant after settling was a similar to that of soluble sample. Total petroleum hydrocarbon (TPH) was mostly present in the adsorbed form to the particles in the groundwater and was potentially persistent to Fenton oxidation. TPH removal efficiency by Fenton oxidation was 24% which was less than that of the total groundwater indicating that hydroxyl radicals generated from Fenton oxidation did not directly attack the adsorbed organic carbon and removal of the adsorbed organic carbon was dependent on its mass transfer to bulk region. The concept for particle effect on Fenton oxidation was confirmed in another experiment spiking washed soil to the soluble groundwater. TOC removal efficiency was lowered by addition of the soil probably because the

  17. Pretreatment of furfural industrial wastewater by Fenton, electro-Fenton and Fe(II)-activated peroxydisulfate processes: a comparative study.

    Science.gov (United States)

    Yang, C W; Wang, D; Tang, Q

    2014-01-01

    The Fenton, electro-Fenton and Fe(II)-activated peroxydisulfate (PDS) processes have been applied for the treatment of actual furfural industrial wastewater in this paper. Through the comparative study of the three processes, a suitable pretreatment technology for actual furfural wastewater treatment was obtained, and the mechanism and dynamics process of this technology is discussed. The experimental results show that Fenton technology has a good and stable effect without adjusting pH of furfural wastewater. At optimal conditions, which were 40 mmol/L H₂O₂ initial concentration and 10 mmol/L Fe²⁺ initial concentration, the chemical oxygen demand (COD) removal rate can reach 81.2% after 90 min reaction at 80 °C temperature. The PDS process also has a good performance. The COD removal rate could attain 80.3% when Na₂S₂O₈ initial concentration was 4.2 mmol/L, Fe²⁺ initial concentration was 0.1 mol/L, the temperature remained at 70 °C, and pH value remained at 2.0. The electro-Fenton process was not competent to deal with the high-temperature furfural industrial wastewater and only 10.2% COD was degraded at 80 °C temperature in the optimal conditions (2.25 mA/cm² current density, 4 mg/L Na₂SO₄, 0.3 m³/h aeration rate). For the Fenton, electro-Fenton and PDS processes in pretreatment of furfural wastewater, their kinetic processes follow the pseudo first order kinetics law. The pretreatment pathways of furfural wastewater degradation are also investigated in this study. The results show that furfural and furan formic acid in furfural wastewater were preferentially degraded by Fenton technology. Furfural can be degraded into low-toxicity or nontoxic compounds by Fenton pretreatment technology, which could make furfural wastewater harmless and even reusable. PMID:25098869

  18. Niobian iron oxides as heterogeneous Fenton catalysts for environmental remediation

    International Nuclear Information System (INIS)

    Heterogeneous Fenton or Fenton-like reagents consist of a mixture of an iron-containing solid matrix and a liquid medium with H2O2. The Fenton system is based on the reaction between Fe2+ and H2O2 to produce highly reactive intermediate hydroxyl radicals (. OH), which are able to oxidize organic contaminants, whereas the Fenton-like reaction is based on the reaction between Fe3+ and H2O2. These heterogeneous systems offer several advantages over their homogeneous counterparts, such as no sludge formation, operation at near-neutral pH and the possibility of recycling the iron promoter. Some doping transition cations in the iron oxide structure are believed to enhance the catalytic efficiency for the oxidation of organic substrates in water. In this work, goethites synthesized in presence of niobium served as precursors for the preparation of magnetites (niobian magnetites) via chemical reduction with hydrogen at 400 deg. C. These materials were used as Fenton-like catalysts. Both groups of (Nb, Fe)-oxide samples were characterized by 57Fe Moessbauer spectroscopy at 298 K. The results show that increasing niobium contents raise the catalytic potential for decomposition of methylene blue, which was, in this work, used as a model molecule for organic substrates in water.

  19. Chemical oxidation of sulfadiazine by the Fenton process: kinetics, pathways, toxicity evaluation.

    Science.gov (United States)

    Yang, Ji-Feng; Zhou, Shi-Biao; Xiao, An-Guo; Li, Wen-Jun; Ying, Guang-Guo

    2014-01-01

    This paper investigated sulfadiazine oxidation by the Fenton process under various reaction conditions. The reaction conditions tested in the experiments included the initial pH value of reaction solutions, and the dosages of ferrous ions and hydrogen peroxide. Under the reaction conditions with pH 3, 0.25 mM of ferrous ion and 2 mM of hydrogen peroxide, a removal efficiency of nearly 100% was achieved for sulfadiazine. A series of intermediate products including 4-OH-sulfadiazine/or 5-OH-sulfadiazine, 2-aminopyrimidine, sulfanilamide, formic acid, and oxalic acid were identified. Based on these products, the possible oxidation pathway of sulfadiazine by Fenton's reagent was proposed. The toxicity evaluation of reaction solutions showed increased antimicrobial effects following the Fenton oxidation process. The results from this study suggest that the Fenton oxidation process could remove sulfadiazine, but also increase solution toxicity due to the presence of more toxic products. PMID:25310806

  20. Avaliação da reação foto-fenton na decomposição de resíduos de carrapaticida Evaluation of the photo-fenton reaction in the decomposition of tick residues

    Directory of Open Access Journals (Sweden)

    Caio Fernando Gromboni

    2007-04-01

    Full Text Available Experimental procedures based on factorial design and surface response methodology were applied to establishe experimental conditions for the decomposition of a 1:400 (v/v Supocade® (chlorfenvinphos 13.8% and cypermethrin 2.6% solution, used to control cattle ticks. Experiments exploring photo-oxidative reactions were performed with and without UV radiation, fixing exposition time and pesticide volume, and varying the oxidant mixture. The use of 3.6 mmol L-1 Fe2+ plus 1.9 mol L-1 H2O2 plus UV radiation provided destruction of 94% of the original carbon content and reduction of aromatic, aliphatic and carbinolic compounds, evaluated by determination of residual carbon content by ICP OES and NMR analysis.

  1. Tertiary treatment of pulp mill wastewater by solar photo-Fenton

    International Nuclear Information System (INIS)

    Highlights: ► We firstly report a real pulp mill wastewater treatment by solar photo-Fenton in a CPC reactor. Fenton reagent experiments were tested firstly. ► Solar photo-Fenton presents excellent ability to treat the pulp mill wastewater. ► Experimental conditions were optimised. ► Biodegradability and toxicity tests (respirometry assays and BOD5/COD ratio) were performed during the wastewater treatment. ► A way to reduce the economic and environmental impact was evaluated. - Abstract: This work reports on pulp mill wastewater (PMW) tertiary treatment by Fenton (Fe2+/H2O2) and solar photo-Fenton (Fe2+/H2O2/UV) processes in a pilot plant based on compound parabolic collectors (CPCs). Solar photo-Fenton reaction is much more efficient than the respective dark reaction under identical experimental conditions. It leads to DOC mineralisation, COD and total polyphenols (TP) removal higher than 90%. The solar photo-Fenton experiment with 5 mg Fe L−1 reaches 90% of DOC mineralisation with 31 kJ L−1 of UV energy and 50 mM of H2O2. The initial non-biodegradability of PMW, as shown by respirometry assays and BOD5/COD ratio, can be changed after a solar photo-Fenton treatment. Experiments with 20 and 50 mg Fe L−1 revealed that solar photo-Fenton can reach the same DOC degradation (90%), however, consuming less H2O2 and time. Diluting the initial organic load to 50% also diminishes the dosage of H2O2 and the necessary reaction time to achieve high DOC removals. Accordingly, solar photo-Fenton can be considered an alternative or complementary process to improve the performance of a biologic treatment and, subsequently, achieve legal limits on discharge into natural waters.

  2. Mineralization of herbicide 3,6-dichloro-2-methoxybenzoic acid in aqueous medium by anodic oxidation, electro-Fenton and photoelectro-Fenton

    International Nuclear Information System (INIS)

    The mineralization of acidic aqueous solutions with 230 and 115 ppm of herbicide 3,6-dichloro-2-methoxybenzoic acid (dicamba) in 0.05 M Na2SO4 of pH 3.0 has been studied by electro-Fenton and photoelectro-Fenton using a Pt anode and an O2-diffusion cathode, where oxidizing hydroxyl radicals are produced from Fenton's reaction between added Fe2+ and H2O2 generated by the cathode. While electro-Fenton only yields 60-70% mineralization, photoelectro-Fenton allows a fast and complete depollution of herbicide solutions, even at low currents, by the action of UV irradiation. In both treatments, the initial chlorine is rapidly released to the medium as chloride ion. Comparative electrolyses by anodic oxidation in the absence and presence of electrogenerated H2O2 give very poor degradation. The dicamba decay follows a pseudo-first-order reaction, as determined by reverse-phase chromatography. Formic, maleic and oxalic acids have been detected in the electrolyzed solutions by ion-exclusion chromatography. In electro-Fenton, all formic acid is transformed into CO2, and maleic acid is completely converted into oxalic acid, remaining stable Fe3+-oxalato complexes in the solution. The fast mineralization of such complexes by UV light explains the highest oxidative ability of photoelectro-Fenton

  3. Preparation and application of cellulose acetate/Fe films in the degradation of Reactive Black 5 dye through photo-Fenton reaction.

    Science.gov (United States)

    Ribeiro, Karine; de Andrade, Tamara Maria; Fujiwara, Sérgio Toshio

    2016-07-01

    In this study, the Reactive Black 5 dye degradation and textile effluent were investigated using the photo-Fenton process employing immobilized Fe(3+) in acetate cellulose films. The films prepared were characterized through Fourier transform infrared spectroscopy, atomic absorption spectroscopy, scanning electron microscopy - energy-dispersive spectroscopy and ultraviolet visible spectroscopy. The factorial design revealed that the best conditions for the Reactive Black 5 dye degradation were obtained using the film containing 5% Fe (w/w), 100 mg L(-1) H2O2 and pH 4.0. In studies using artificial light, the dye degradation was 99.29% and the chemical oxygen demand (COD) reduction was 90% after 45 min of treatment. In the process assisted by sunlight, the degradation was 86% and the COD reduction was 70% considering the same time of treatment. At pH 6.0 and artificial light, the dye degradation was 98.90% and the COD reduction was 78%, indicating that the material prepared can be used at pH values greater than 3 without the occurrence of hydrated ferric oxides precipitation. It was also observed that the material can be reused seven consecutive times without substantial loss of efficacy in dye degradation. Furthermore, the proposed material reduces the COD of a textile effluent by 72% after 300 min of treatment. PMID:26675986

  4. Sulfate radicals induced from peroxymonosulfate by cobalt manganese oxides (Co{sub x}Mn{sub 3−x}O{sub 4}) for Fenton-Like reaction in water

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Yunjin, E-mail: yaoyunjin@gmail.com [Anhui Key Lab of Controllable Chemical Reaction & Material Chemical Engineering, School of Chemistry and Chemical Engineering, Hefei University of Technology, Tunxi Road 193, Hefei 230009 (China); State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology, Nanjing 210009 (China); School of Chemistry and Materials Science, University of Science and Technology of China, Hefei, Anhui 230026 (China); Cai, Yunmu; Wu, Guodong; Wei, Fengyu [Anhui Key Lab of Controllable Chemical Reaction & Material Chemical Engineering, School of Chemistry and Chemical Engineering, Hefei University of Technology, Tunxi Road 193, Hefei 230009 (China); Li, Xingya [School of Chemistry and Materials Science, University of Science and Technology of China, Hefei, Anhui 230026 (China); Chen, Hao [Anhui Key Lab of Controllable Chemical Reaction & Material Chemical Engineering, School of Chemistry and Chemical Engineering, Hefei University of Technology, Tunxi Road 193, Hefei 230009 (China); Wang, Shaobin, E-mail: shaobin.wang@curtin.edu.au [Department of Chemical Engineering, Curtin University, G.P.O. Box U1987, Perth, Western Australia 6845 (Australia)

    2015-10-15

    Highlights: • A series of Co{sub x}Mn{sub 3−x}O{sub 4} particles as Fenton-like solid catalysts were synthesized. • CoMn{sub 2}O{sub 4}/PMS exhibits high activity due to synergistic effects of Co and Mn species. • Reaction conditions and degradation mechanism have been analyzed. • Contributions from SO{sub 4}·{sup −} and HO· radicals to the reaction were measured using scavengers. • The catalyst had good stability and reusability during the five successive runs. - Abstract: A series of Co{sub x}Mn{sub 3−x}O{sub 4} particles as Fenton-like solid catalysts were synthesized, and their catalytic performance in oxidative degradation of organic dye compounds in water was investigated. The surface morphology and structure of the Co{sub x}Mn{sub 3−x}O{sub 4} catalysts were characterized by field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), powder X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The results showed that, as an oxide composite of Co and Mn elements, CoMn{sub 2}O{sub 4} showed much stronger catalytic activity in peroxymonosulfate (PMS) oxidation than Co{sub 3}O{sub 4}, Mn{sub 2}O{sub 3,} and their physical mixture. Typically, the uses of 0.02 g/dm{sup 3} CoMn{sub 2}O{sub 4} and 0.2 g/dm{sup 3} PMS yielded a nearly complete removal of Rhodamine B (0.03 g/dm{sup 3}) in 80 min at 25 °C. The efficiency of Rhodamine B decomposition increased with increasing temperature (15–55 °C), but decreased with the increase of fulvic acid concentration (0–0.08 g/dm{sup 3}). Furthermore, CoMn{sub 2}O{sub 4} could maintain its catalytic activity in the repeated batch experiments. Moreover, HO· and SO{sub 4}·{sup −} radicals participating in the process were evidenced using quenching experiments, and a rational mechanism was proposed. PMS oxidation with CoMn{sub 2}O{sub 4} is an efficient technique for remediation of organic contaminants in

  5. Sulfate radicals induced from peroxymonosulfate by cobalt manganese oxides (Co(x)Mn(3-x)O4) for Fenton-Like reaction in water.

    Science.gov (United States)

    Yao, Yunjin; Cai, Yunmu; Wu, Guodong; Wei, Fengyu; Li, Xingya; Chen, Hao; Wang, Shaobin

    2015-10-15

    A series of CoxMn3-xO4 particles as Fenton-like solid catalysts were synthesized, and their catalytic performance in oxidative degradation of organic dye compounds in water was investigated. The surface morphology and structure of the CoxMn3-xO4 catalysts were characterized by field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), powder X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The results showed that, as an oxide composite of Co and Mn elements, CoMn2O4 showed much stronger catalytic activity in peroxymonosulfate (PMS) oxidation than Co3O4, Mn2O3, and their physical mixture. Typically, the uses of 0.02 g/dm(3) CoMn2O4 and 0.2 g/dm(3) PMS yielded a nearly complete removal of Rhodamine B (0.03 g/dm(3)) in 80 min at 25 °C. The efficiency of Rhodamine B decomposition increased with increasing temperature (15-55 °C), but decreased with the increase of fulvic acid concentration (0-0.08 g/dm(3)). Furthermore, CoMn2O4 could maintain its catalytic activity in the repeated batch experiments. Moreover, HO· and SO4(·-) radicals participating in the process were evidenced using quenching experiments, and a rational mechanism was proposed. PMS oxidation with CoMn2O4 is an efficient technique for remediation of organic contaminants in wastewater. PMID:25913679

  6. Magnetic minerals from volcanic Ultisols as heterogeneous Fenton catalysts

    International Nuclear Information System (INIS)

    This study was devoted to the evaluation of the effectiveness of Fenton catalysts, based on magnetically-concentrated portions of iron oxide-rich sand fractions from two magnetic Ultisols, derived from volcanic materials of southern Chile. The samples were labeled according to the municipality where the sample sites are geographically located, namely Metrenco and Collipulli, and were characterized with Moessbauer spectroscopy at 298 K and saturation magnetization (σ) measurements. Moessbauer data revealed a complex magnetic hyperfine structure for these magnetic portions from both soil-sand materials, suggesting relatively complex mineral assemblages. The monitored rate of H2O2 decomposition via heterogeneous Fenton reaction revealed that materials from the Collipulli soil are more efficient Fenton catalyst than are those from the Metrenco soil. The reasons for these differences are from now on being explored on basis of a more detailed chemical investigation of these samples.

  7. Municipal solid waste landfill leachate treatment by fenton, photo-fenton and fenton-like processes: Effect of some variables

    Directory of Open Access Journals (Sweden)

    Zazouli Mohammad

    2012-08-01

    Full Text Available Abstract Advanced oxidation processes like Fenton and photo-Fenton have been effectively applied to oxidize the persistent organic compounds in solid waste leachate and convert them to unharmful materials and products. However, there are limited data about application of Fenton-like process in leachate treatment. Therefore, this study was designed with the objective of treating municipal landfill leachate by Fenton, Fenton-like and photo–Fenton processes to determine the effect of different variables, by setting up a pilot system. The used leachate was collected from a municipal unsanitary landfill in Qaem-Shahr in the north of Iran. Fenton and Fenton-like processes were conducted by Jar-test method. Photo-Fenton process was performed in a glass photo-reactor. In all processes, H2O2 was used as the oxidant. FeSO4.7H2O and FeCl3.6H2O were used as reagents. All parameters were measured based on standard methods. The results showed that the optimum concentration of H2O2 was equal to 5 g/L for the Fenton-like process and 3 g/L for the Fenton and photo-Fenton processes. The optimum ratio of H2O2: Fe+2/Fe+3 were equal to 8:1 in all processes. At optimum conditions, the amount of COD removal was 69.6%, 65.9% and 83.2% in Fenton, Fenton-like and photo–Fenton processes, respectively. In addition, optimum pH were 3, 5 and 3 and the optimum contact time were 150, 90 and 120 minutes, for Fenton, Fenton-like and photo–Fenton processes, respectively. After all processes, the biodegradability (BOD5/COD ratio of the treated leachate was increased compared to that of the raw leachate and the highest increase in BOD5/COD ratio was observed in the photo-Fenton process. The efficiency of the Fenton-like process was overally less than Fenton and photo-Fenton processes, meanwhile the Fenton-like process was at higher pH and did not show problems.

  8. Advanced Treatment of Pesticide-Containing Wastewater Using Fenton Reagent Enhanced by Microwave Electrodeless Ultraviolet.

    Science.gov (United States)

    Cheng, Gong; Lin, Jing; Lu, Jian; Zhao, Xi; Cai, Zhengqing; Fu, Jie

    2015-01-01

    The photo-Fenton reaction is a promising method to treat organic contaminants in water. In this paper, a Fenton reagent enhanced by microwave electrodeless ultraviolet (MWEUV/Fenton) method was proposed for advanced treatment of nonbiodegradable organic substance in pesticide-containing biotreated wastewater. MWEUV lamp was found to be more effective for chemical oxygen demand (COD) removal than commercial mercury lamps in the Fenton process. The pseudo-first order kinetic model can well describe COD removal from pesticide-containing wastewater by MWEUV/Fenton, and the apparent rate constant (k) was 0.0125 min(-1). The optimal conditions for MWEUV/Fenton process were determined as initial pH of 5, Fe(2+) dosage of 0.8 mmol/L, and H2O2 dosage of 100 mmol/L. Under the optimal conditions, the reaction exhibited high mineralization degrees of organics, where COD and dissolved organic carbon (DOC) concentration decreased from 183.2 mg/L to 36.9 mg/L and 43.5 mg/L to 27.8 mg/L, respectively. Three main pesticides in the wastewater, as Dimethoate, Triazophos, and Malathion, were completely removed by the MWEUV/Fenton process within 120 min. The high degree of pesticides decomposition and mineralization was proved by the detected inorganic anions. PMID:26347877

  9. Fenton Oxidation of Methyl Violet in Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Saeedeh Hashemian

    2013-01-01

    Full Text Available In this study, oxidative discoloration of methyl violet (MV dye in aqueous solution has been studied using Fenton (Fe2+/H2O2 process. The parameters such as concentration of Fe2+, H2O2, MV, temperature, and Cl− and ions that affected of discoloration in Fenton process were investigated. The rate of degradation is dependent on initial concentration of Fe2+ ion, initial concentration of H2O2, and pH of media. Discoloration of MV was increased by increasing the temperature of reaction. Optimized condition was determined and it was found that the obtained efficiency was about 95.5% after 15 minutes of reaction at pH 3. TOC of dye sample, before and after the oxidation process, was determined. TOC removal indicates partial and significant mineralization of MV dye. The results of experiments showed that degradation of MV dye in Fenton oxidation can be described with a pseudo-irst-order kinetic model. The thermodynamic constants of the Fenton oxidation process were evaluated. The results implied that the oxidation process was feasible, spontaneous, and endothermic.

  10. Electrochemical dissolution of steel as a typical catalyst for electro-Fenton oxidation

    OpenAIRE

    Kočanová, Veronika; Dušek, Libor

    2016-01-01

    Abstract Although traditional Fenton reaction is known for a long time, it is still a perspective method for removal of pollution from wastewater. Applications of electro-Fenton oxidation are commonly used in wastewater treatment. These methods are classified into groups—electrochemical advanced oxidation processes. Typical catalysts for these technologies are Fe2+ ions. Comparison between two material types of steel was investigated in this paper. Alloy steel Cr–Ni and non-alloy steel were u...

  11. Combined UV/ Fenton and SBR Treatment of a Semi-aerobic Landfill Leachate

    International Nuclear Information System (INIS)

    This study examined the combined UV/ Fenton and sequencing batch biological reactor (SBR) treatment of a semi-aerobic landfill leachate. Fenton pretreatment of the leachate was optimized by the response surface methodology (RSM). UV/ Fenton pretreatment of the leachate was performed under the optimum operating conditions of the Fenton pretreatment (H2O2/ COD molar ratio 2.25, H2O2/ Fe2+ molar ratio 10.0 and reaction/ irradiation time 1.5 h). The characteristics of the UV/ Fenton pretreated leachate were: COD 390 mg/ L, sCOD 330 mg/L, BOD5 136 mg/L, BOD5/ COD ratio 0.35, NH3-N 112 mg/ L, TKN 157 mg/ L, NO3--N 6.8 mg/ L and colour 99 Pt-Co Unit. SBR treatment of the UV/ Fenton pretreated leachate resulted in sCOD, BOD5 and NH3-N removal of 78 %, 81 % and 88 %, respectively. The final effluent characteristics were: COD 92 mg/ L, sCOD 71 mg/L, BOD5 26 mg/ L, NH3-N 7 mg/ L, NO3--N 27 mg/ L, TKN 13 mg/ L and TSS 38 mg/ L. The effluent met the Malaysian discharge standard (B) - COD 100 mg/ L, BOD5 50 mg/ L and TSS 100 mg/ L. Combined UV/ Fenton and SBR is an effective treatment for mature leachate from semi-aerobic landfill. (author)

  12. Removal of citrate and hypophosphite binary components using Fenton, photo-Fenton and electro-Fenton processes

    Institute of Scientific and Technical Information of China (English)

    Yao-Hui Huang; Hsiao-Ting Su; Li-Way Lin

    2009-01-01

    Both citrate and hypophosphite in aqueous solution were degraded by advanced oxidation processes (Fe2+/H2O2, UV/Fe2+/H2O2, and electrolysis/ Fe2+/H2O2) in this study. Comparison of these techniques in oxidation efficiency was undertaken. It was found that Fenton process could not degrade completely citrate in the presence of hypophosphite since it caused a series inhibition. Therefore, UV light (photo-Fenton) or electron current (electro-Fenton) was applied to improve the degradation efficiency of the Fenton process. Results showed that both photo-Fenton and electro-Fenton processes could overcome the inhibition of hypophosphite, especially the electro-Fenton.

  13. Microcystin-LR degradation by solar photo-Fenton, UV-A/photo-Fenton and UV-C/H2O2: a comparative study.

    Science.gov (United States)

    de Freitas, Adriane M; Sirtori, Carla; Lenz, Cesar A; Peralta Zamora, Patricio G

    2013-04-01

    This work assessed the effectiveness of several methods on degradation of microcystin-LR (MC-LR) by different Advanced Oxidation Processes, like solar photo-Fenton, UV-A/photo-Fenton and UV-C/H2O2. UV-C/H2O2 and UV-A/photo-Fenton processes were carried out in a bench scale photochemical apparatus and the solar photo-Fenton treatment was performed in a CPC photoreactor. MC-LR degradation was monitored by LC-ESI-MS/MS and kinetic parameters were calculated for all systems evaluated. The results demonstrated that UV-C/H2O2 was the most efficient method, showing a reduction of over 90% of initial MC-LR after 5 min of reaction. Solar and photo-Fenton/UVA had a rate decrease of 88 and 76% after the same time, respectively. The kinetic study indicated that the solar photo-Fenton and artificial radiation (UV-A) processes were very similar in their efficiency. The use of sunlight instead of artificial UV radiation significantly reduced the cost of photocatalytic treatment systems; it is also an environmentally friendly method, since it utilizes renewable energy. PMID:23178743

  14. Avaliação da potencialidade de processos pseudo-fenton para remediação de solos contaminados por diesel Evaluation of potencial fenton-like process to the remediation of contaminated soils by diesel

    Directory of Open Access Journals (Sweden)

    Carolina Acioli Pereira

    2009-01-01

    Full Text Available The use of the Fenton's reagent process has been investigated for the remediation of a Brazilian soil contaminated by diesel. Laboratory experiments were conducted in batch experiments. Slurries, consisting of 10 g of diesel-contaminated soil and 30 mL of Fenton's Reagent (0.41 mol L-1 H(20(2 and 0.18 mol L-1 FeSO4. The experiments were monitored during 24, 48 and 72 h. The efficiency of the Fenton treatment was dependent on the time of contact between soil and Fenton's reagents and matrix characteristics, probably iron content. Data suggested that no iron addition is needed for the application of Fenton-like treatment for the remediation of diesel-contaminated iron rich soils after 72 h reaction.

  15. Effect of Hydrogen Peroxide Induced Fenton Reaction on Biomass of Rice in Soil Contaminated by Cd and As%H2O2介导的Fenton反应对砷镉污染下水稻生物量的影响

    Institute of Scientific and Technical Information of China (English)

    黎俏文; 秦俊豪; 陈桂葵; 黎华寿

    2015-01-01

    A pot experiment using a rhizo-bag system filled with soil and sand was conducted to investigate if rice growth was influenced by Fenton Reaction induced by hydrogen peroxide at micro molar level from simulated rain water in arsenic and/or cadmium contaminated pad-dy soil under all-time flooding and partial flooding. Results show that the Fenton Reaction significantly improved the dry weight and fresh weight of rice at tillering stage in the treatment with 30 mg As·kg-1 soil, and at maturing stage in the treatment with both 30 mg As·kg-1 soil and 0.3 mg Cd·kg-1 soil. Fenton Reaction also improved the weight of rice grain in treatments with 0.3 mg Cd·kg-1 soil and 3 mg Cd·kg-1 soil. These findings prove that Fenton Reaction could reduce the negative impacts of arsenic and cadmium contamination on rice growth and increase rice biomass and yield.%采用土壤-石英砂根袋法,研究了淹水和干湿交替两种水分条件下,模拟天然降雨中微摩尔级浓度H2O2介导Fenton反应对砷镉污染土壤上水稻生长的影响。结果表明,添加砷浓度30 mg·kg-1处理组在有Fenton反应的情况下显著提高了水稻在分蘖期的干重和鲜重,在添加砷浓度30 mg·kg-1和镉浓度0.3 mg·kg-1的复合污染处理组Fenton反应也提高了水稻在成熟期的干重和鲜重,同时Fenton反应增加了添加镉浓度为0.3、3 mg·kg-1处理组的稻谷产量。模拟研究证明,H2O2介导的Fenton反应可以缓解砷、镉污染对水稻的胁迫作用,提高水稻的生物量和产量。

  16. Potential of Ceria-Based Catalysts for the Oxidation of Landfill Leachate by Heterogeneous Fenton Process

    Directory of Open Access Journals (Sweden)

    E. Aneggi

    2012-01-01

    Full Text Available In this study, ceria and ceria-zirconia solid solutions were tested as catalyst for the treatment of landfill leachate with a Fenton-like process. The catalysts considered in this work were pure ceria and ceria-zirconia solid solutions as well as iron-doped samples. All the catalysts were extensively characterized and applied in batch Fenton-like reactions by a close batch system, the COD (chemical oxygen demand and TOC (total organic carbon parameters were carried out before and after the treatments in order to assay oxidative abatement. Results show a measurable improvement of the TOC and COD abatement using ceria-based catalysts in Fenton-like process and the best result was achieved for iron-doped ceria-zirconia solid solution. Our outcomes point out that heterogeneous Fenton technique could be effectively used for the treatment of landfill leachate and it is worth to be the object of further investigations.

  17. An aromatic hydroxylation assay for hydroxyl radicals utilizing high-performance liquid chromatography (HPLC). Use to investigate the effect of EDTA on the Fenton reaction.

    Science.gov (United States)

    Grootveld, M; Halliwell, B

    1986-01-01

    A highly sensitive HPLC method for the separation of hydroxylation products derived from the attack of hydroxyl radical upon phenol is described. Catechol and hydroquinone are the major hydroxylation products formed, with little resorcinol. The effect of EDTA upon hydroxyl radical generation from an iron (II)-H2O2 system is shown to depend upon the order of addition of chelator and metal ion to the reaction mixture, the ratio [iron salt]/[chelator] and the presence or absence of a phosphate buffer. Reasons for these different effects are discussed. PMID:2849582

  18. Photo-Fenton treatment of water containing natural phenolic pollutants.

    Science.gov (United States)

    Gernjak, Wolfgang; Krutzler, Thomas; Glaser, Andreas; Malato, Sixto; Caceres, Julia; Bauer, Rupert; Fernández-Alba, A R

    2003-01-01

    Phenolic compounds are known to be present in high concentrations in various types of agro-industrial wastes. As they are highly biorecalcitrant, the possibility of treatment by advanced oxidation processes should be investigated. In this work, six model phenolic compounds (vanillin, protocatechuic acid, syringic acid, p-coumaric acid, gallic acid and L-tyrosine) were chosen for a demonstration of degradation by photo-Fenton reaction, under artificial light in laboratory experiments in Vienna and under sunlight in pilot-plant experiments at the Plataforma Solar de Almería in Spain. All compounds were completely mineralised. No non-degradable intermediates were produced, either in experiments with single substances or in a more complex matrix of a mixture of phenolic compounds. The expected selectivity of the photo-Fenton reaction for aromatic compounds was proven by comparison of the decrease in total organic carbon with the removal of total phenolic content. PMID:12656231

  19. Enhancement of activated sludge disintegration and dewaterability by Fenton process

    Science.gov (United States)

    Heng, G. C.; Isa, M. H.

    2016-06-01

    Municipal and industrial wastewater treatment plants produce large amounts of sludge. This excess sludge is an inevitable drawback inherent to the activated sludge process. In this study, the waste activated sludge was obtained from the campus wastewater treatment plant at Universiti Teknologi PETRONAS (UTP), Malaysia. Fenton pretreatment was optimized by using the response surface methodology (RSM) to study the effects of three operating conditions including the dosage of H2O2 (g H2O2/kg TS), the molar ratio of H2O2/Fe2+ and reaction time. The optimum operating variables to achieve MLVSS removal 65%, CST reduction 28%, sCOD 11000 mg/L and EPS 500 mg/L were: 1000 g H2O2/kg TS, H2O2/Fe2+ molar ratio 70 and reaction time 45 min. Fenton process was proved to be able to enhance the sludge disintegration and dewaterability.

  20. Electrochemical treatment of Acid Red 1 by electro-Fenton and photoelectro-Fenton processes

    Directory of Open Access Journals (Sweden)

    Camilo González-Vargas

    2014-12-01

    Full Text Available Small volumes (100 mL of acidic aqueous solutions with 30-200 mg L-1 TOC of the toxic azo dye Acid Red 1 (AR1 have been comparatively treated by various electrochemical advanced oxidation processes (EAOPs. The electrolytic system consisted of a BDD anode able to produce ·OH and an air-diffusion cathode that generated H2O2, which subsequently reacted with added Fe2+ to yield additional ·OH from Fenton’s reaction. Under optimized conditions (i.e., 1.0 mM Fe2+, 60 mA cm-2, pH 3.0, 35 ºC, the analysis of the initial rates for decolourization and AR1 decay assuming a pseudo-first-order kinetics revealed a much higher rate constant for photoelectro-Fenton (PEF, ~ 2.7x10-3 s-1 compared to electro-Fenton (EF, ~ 0.6x10-3 s-1. Mineralization after 180 min was also greater in the former treatment (90 % vs 63 %. The use of UV radiation in PEF contributed to Fe(III photoreduction as well as to photodecarboxylation of refractory intermediates, yielding a mineralization current efficiency as high as 85% during the treatment of solutions of 200 mg L-1 TOC. Primary reaction intermediates included three aromatic derivatives with the initial naphthalenic structure and four molecules only featuring benzenic rings, which were totally mineralized in PEF. 

  1. Electro-Fenton, UVA photoelectro-Fenton and solar photoelectro-Fenton degradation of the drug ibuprofen in acid aqueous medium using platinum and boron-doped diamond anodes

    Energy Technology Data Exchange (ETDEWEB)

    Skoumal, Marcel; Rodriguez, Rosa Maria; Cabot, Pere Lluis; Centellas, Francesc; Garrido, Jose Antonio; Arias, Conchita [Laboratori d' Electroquimica dels Materials i del Medi Ambient, Departament de Quimica Fisica, Facultat de Quimica, Universitat de Barcelona, Marti i Franques 1-11, 08028 Barcelona (Spain); Brillas, Enric [Laboratori d' Electroquimica dels Materials i del Medi Ambient, Departament de Quimica Fisica, Facultat de Quimica, Universitat de Barcelona, Marti i Franques 1-11, 08028 Barcelona (Spain)], E-mail: brillas@ub.edu

    2009-02-28

    The degradation of a 41 mg dm{sup -3} ibuprofen (2-(4-isobutylphenyl)propionic acid) solution of pH 3.0 has been comparatively studied by electrochemical advanced oxidation processes (EAOPs) like electro-Fenton, UVA photoelectro-Fenton and solar photoelectro-Fenton at constant current density. Experiments were performed in a one-compartment cell with a Pt or boron-doped diamond (BDD) anode and an O{sub 2}-diffusion cathode. Heterogeneous hydroxyl radical ({center_dot}OH) is generated at the anode surface from water oxidation, while homogeneous {center_dot}OH is formed from Fenton's reaction between Fe{sup 2+} and H{sub 2}O{sub 2} generated at the cathode, being its production strongly enhanced from photo-Fenton reaction induced by sunlight. Higher mineralization is attained in all methods using BDD instead Pt, because the former produces greater quantity of {center_dot}OH enhancing the oxidation of pollutants. The mineralization rate increases under UVA and solar irradiation by the rapid photodecomposition of complexes of Fe(III) with acidic intermediates. The most potent method is solar photoelectro-Fenton with BDD giving 92% mineralization due to the formation of a small proportion of highly persistent final by-products. The effect of Fe{sup 2+} content, pH and current density on photoelectro-Fenton degradation has been studied. The ibuprofen decay always follows a pseudo-first-order kinetics and its destruction rate is limited by current density and UV intensity. Aromatics such as 1-(1-hydroxyethyl)-4-isobutylbenzene, 4-isobutylacetophenone, 4-isobutylphenol and 4-ethylbenzaldehyde, and carboxylic acids such as pyruvic, acetic, formic and oxalic have been identified as oxidation by-products. Oxalic acid is the ultimate by-product and the fast photodecarboxylation of its complexes with Fe(III) under UVA or solar irradiation explains the higher oxidation power of photoelectro-Fenton methods in comparison to electro-Fenton procedures.

  2. Tertiary treatment of pulp mill wastewater by solar photo-Fenton

    Energy Technology Data Exchange (ETDEWEB)

    Lucas, Marco S., E-mail: mlucas@utad.pt [Centro de Quimica de Vila Real, Universidade de Tras-os-Montes e Alto Douro, Apartado 1013, 5001-801 Vila Real (Portugal); Peres, Jose A.; Amor, Carlos [Centro de Quimica de Vila Real, Universidade de Tras-os-Montes e Alto Douro, Apartado 1013, 5001-801 Vila Real (Portugal); Prieto-Rodriguez, Lucia; Maldonado, Manuel I.; Malato, Sixto [Plataforma Solar de Almeria (CIEMAT), Carretera de Senes, Km 4, 04200, Tabernas, Almeria (Spain)

    2012-07-30

    Highlights: Black-Right-Pointing-Pointer We firstly report a real pulp mill wastewater treatment by solar photo-Fenton in a CPC reactor. Fenton reagent experiments were tested firstly. Black-Right-Pointing-Pointer Solar photo-Fenton presents excellent ability to treat the pulp mill wastewater. Black-Right-Pointing-Pointer Experimental conditions were optimised. Black-Right-Pointing-Pointer Biodegradability and toxicity tests (respirometry assays and BOD{sub 5}/COD ratio) were performed during the wastewater treatment. Black-Right-Pointing-Pointer A way to reduce the economic and environmental impact was evaluated. - Abstract: This work reports on pulp mill wastewater (PMW) tertiary treatment by Fenton (Fe{sup 2+}/H{sub 2}O{sub 2}) and solar photo-Fenton (Fe{sup 2+}/H{sub 2}O{sub 2}/UV) processes in a pilot plant based on compound parabolic collectors (CPCs). Solar photo-Fenton reaction is much more efficient than the respective dark reaction under identical experimental conditions. It leads to DOC mineralisation, COD and total polyphenols (TP) removal higher than 90%. The solar photo-Fenton experiment with 5 mg Fe L{sup -1} reaches 90% of DOC mineralisation with 31 kJ L{sup -1} of UV energy and 50 mM of H{sub 2}O{sub 2}. The initial non-biodegradability of PMW, as shown by respirometry assays and BOD{sub 5}/COD ratio, can be changed after a solar photo-Fenton treatment. Experiments with 20 and 50 mg Fe L{sup -1} revealed that solar photo-Fenton can reach the same DOC degradation (90%), however, consuming less H{sub 2}O{sub 2} and time. Diluting the initial organic load to 50% also diminishes the dosage of H{sub 2}O{sub 2} and the necessary reaction time to achieve high DOC removals. Accordingly, solar photo-Fenton can be considered an alternative or complementary process to improve the performance of a biologic treatment and, subsequently, achieve legal limits on discharge into natural waters.

  3. Electro-Fenton degradation of antimicrobials triclosan and triclocarban

    International Nuclear Information System (INIS)

    The antimicrobials triclosan (2,4,4'-trichloro-2'-hydroxydiphenyl ether) and triclocarban (N-(4-chlorophenyl)-N'-(3,4-dichlorophenyl)urea) have been degraded by four electro-Fenton systems using undivided electrolytic cells with a Pt or boron-doped diamond (BDD) anode and a carbon felt or O2 diffusion cathode. The main oxidant is hydroxyl radical (·OH) produced both on the anode surface from water oxidation and in the medium by Fenton's reaction, which takes place between electrogenerated H2O2 and Fe2+ coming from cathodic reduction of O2 and Fe3+, respectively. Triclosan from saturated aqueous solutions of pH 3.0 is completely removed in all cells, decreasing its decay rate in the order: Pt/carbon felt > BDD/carbon felt > Pt/O2 diffusion > BDD/O2 diffusion, in agreement with their ·OH generation ability from Fenton's reaction. Glyoxylic, maleic and oxalic acids are identified as aliphatic intermediates. Complexes between oxalic acid and iron ions persist largely in solution, although Fe2+-oxalato complexes are mineralized by ·OH in the medium and Fe3+-oxalato complexes are destroyed by ·OH on BDD. Analogous treatments of more concentrated triclosan solutions using a 20:80 (v/v) acetonitrile/water mixture as solvent evidence the role of hydroxyl radicals along the degradation. In this hydroorganic medium hydroxylated derivatives such as 2,4-dichlorophenol, 4-chlorocatechol, chlorohydroquinone and chloro-p-benzoquinone, and carboxylic acids such as maleic, oxalic, formic and acetic acids are detected as products. Complete destruction of iron-oxalato complexes and released Cl- ion involves some oxidizing species coming from parallel acetonitrile oxidation. The same electro-Fenton systems also yield the overall removal of triclocarban in acetonitrile/water mixtures, giving rise to urea, hydroquinone, chlorohydroquinone, 1-chloro-4-nitrobenzene and 1,2-dichloro-4-nitrobenzene as primary intermediates

  4. Fenton-Like Oxidation of Malachite Green Solutions: Kinetic and Thermodynamic Study

    OpenAIRE

    Saeedeh Hashemian

    2013-01-01

    Oxidation by Fenton-like (Fe3+/H2O2) reactions is proven to be an economically feasible process for destruction of a variety of hazardous pollutants in wastewater. In this study, the degradation and mineralization of malachite green dye are reported using Fenton-like reaction. The effects of different parameters like pH of the solution, the initial concentrations of Fe3+, H2O2, and dye, temperature, and added electrolytes (Cl− and ) on the oxidation of the dye were investigated. Optimized con...

  5. 2-chlorophenol oxidation kinetic by photo-assisted Fenton process

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Experimental data are presented to test and validate a kinetic model for the oxidation of 2-chlorophenol wastewater by photo-assistedFenton process. The data showed that this process had produced good effects under acidic conductions. Up to 90% 2-chlorophenol was removedafter 90-minute reaction time with H2 O2 of 25 % CODcr in while in UV/H2 O2 system only 16.8% 2-chlorophenol was removed after one hourtreatment. The optimal pH in this reaction occurred between pH 3.0 and pH 4.0. The reaction kinetics for photo-assisted Fenton processexperimented in this research was investigated. Kinetic models were proposed for the treatment of 2-chlorophenol wastewater. The reaction wasfound to follow the 2nd order. The equations of reaction kinetics are as follows: - dt/d[RH]= KRH [ RH] [ H2O2 ]0exp(-KH2O2t); -dt/d[CODcr]= KCODCr[CODCr][ H2O2 ]0exp( - K't). The prediction of the models was found to be in a good agreement with experimentalresults, thus confirming the proposed reaction mechanism.

  6. Biosynthetic Schwertmannite as Catalyst in Fenton-liKe Reactions for Degradation of Methyl Orange%生物合成施氏矿物作为类芬顿反应催化剂降解甲基橙的研究

    Institute of Scientific and Technical Information of China (English)

    汪快兵; 方迪; 徐峙晖; 施瑛; 郑冠宇; 周立祥

    2015-01-01

    应用生物合成施氏矿物作为光助类芬顿反应催化剂促进甲基橙的降解.施氏矿物通过A. f-LX5细胞悬浮液在初始pH值2.5和28℃时氧化FeSO43d生成,并进行X射线衍射和扫描电子显微镜表征.本研究分析了不同初始pH、H2 O2浓度及催化剂装载量对在光助类芬顿反应中甲基橙氧化降解效率的影响.结果表明,生物合成施氏矿物具有较高的催化活性,并且通过羟基自由基机制使甲基橙降解.在近中性、较高Cl-、SO2-4及NO3-浓度条件下,施氏矿物仍然能保持较高催化甲基橙降解的效率.本研究验证了以生物合成施氏矿物作为催化剂的异相光助类芬顿反应是一种处理含甲基橙废水有应用前景的高级氧化技术.%Biosynthesized schwertmannite was used as catalyst in photo-Fenton-like reaction to facilitate the degradation of methyl orange ( MO) . Schwertmannite was synthesized through the oxidation of FeSO4 by Acidithiobacillus ferrooxidans LX5 cell suspension at an initial pH 2. 5 and 28℃ for 3 days and characterized using X-ray diffraction spectroscopy and scanning electron microscope. The oxidative degradation of MO in the photo-Fenton-like reaction was studied at different initial pH values of suspension, concentrations of H2 O2 and dosages of catalyst. The results suggested that the biosynthetic schwertmannite showed a good catalytic activity in the MO degradation via ·OH radical mechanism. Considerable degradation efficiency of MO was still obtained in approximately neutral condition or in the presence of high concentrations of chloride, sulfate and nitrate. This work demonstrated that the heterogeneous photo-Fenton-like reaction catalyzed by the biosynthetic schwertmannite is a promising advanced oxidation technology for the treatment of wastewater containing MO.

  7. Glutamic acid modified fenton system for degradation of BTEX contamination

    Energy Technology Data Exchange (ETDEWEB)

    Yehia, Fatma Z.; Badawi, Abdelfatah M.; Mady, Amr H. [Department of Petrochemicals, Egyptian Petroleum Research Institute, Nasr City, Cairo (Egypt); Kandile, Nadia G. [Faculty of Women, Department of Chemistry, Ain Shams University, Heliopolis, Cairo (Egypt)

    2012-07-15

    The present study employed a modified Fenton system that aims to extend the optimum pH range towards neutral conditions for studying the oxidation of benzene, toluene, ethyl benzene, xylenes (BTEX) using glutamic acid (Glu) as an iron chelator. Addition of 20 mM Glu greatly enhanced the oxidation rate of BTEX in modified Fenton system at pH 5-7. A rapid mass destruction (>97% after 1 h) of BTEX as a water contaminant carried out in the presence of 500 mM H{sub 2}O{sub 2}, 10 mM Fe{sup 2+}, and 20 mM Glu at pH 5 could be shown. The efficiency of this modified Fenton's system for mass destruction of BTEX in contaminated water was measured to estimate the impact of the major process variables that include initial concentrations of soluble Fe, H{sub 2}O{sub 2}, Glu (as metal chelating agent), and reaction time. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. Photo-Fenton and Fenton Oxidation of Recalcitrant Industrial Wastewater Using Nanoscale Zero-Valent Iron

    OpenAIRE

    Henrik Hansson; Fabio Kaczala; Marcia Marques; William Hogland

    2012-01-01

    There is a need for the development of on-site wastewater treatment technologies suitable for “dry-process industries,” such as the wood-floor sector. Due to the nature of their activities, these industries generate lower volumes of highly polluted wastewaters after cleaning activities. Advanced oxidation processes such as Fenton and photo-Fenton, are potentially feasible options for treatment of these wastewaters. One of the disadvantages of the Fenton process is the formation of large amoun...

  9. Fundamentos e aplicações ambientais dos processos fenton e foto-fenton Fundaments and environmental applications of fenton and photo-fenton processes

    Directory of Open Access Journals (Sweden)

    Raquel F. Pupo Nogueira

    2007-04-01

    Full Text Available Wastewater and soil treatment processes based on Fenton's reagent have gained great attention in recent years due to its high oxidation power. This review describes the fundaments of the Fenton and photo-Fenton processes and discusses the main aspects related to the degradation of organic contaminants in water such as the complexation of iron, the use of solar light as the source of irradiation and the most important reactor types used. An overview of the main applications of the process to a variety of industrial wastewater and soil remediations is presented.

  10. Optimizing the treatment of landfill leachate by conventional Fenton and photo-Fenton processes

    International Nuclear Information System (INIS)

    Landfill, a matured and economically appealing technology, is the ultimate approach for the management of municipal solid wastes. However, the inevitable generation of leachate from landfill requires further treatment. Among the various leachate treatment technologies available, advanced oxidation processes (AOPs) are among powerful methods to deal with the refractory organic constituents, and the Fenton reagent has evolved as one promising AOPs for the treatment of leachates. Particularly, the combination of UV-radiation with Fenton's reagent has been reported to be a method that allows both the photo-regeneration of Fe2+ and photo-decarboxylation of ferric carboxylates. In this study, Fenton and photo-Fenton processes were fine tuned for the treatment of leachates from the Colmenar Viejo (Madrid, Spain) Landfill. Results showed that it is possible to define a set of conditions under which the same COD and TOC removals (approx 70%) could be achieved with both the conventional and photo-Fenton processes. But Fenton process generated an important quantity of iron sludge, which will require further disposal, when performed under optimal COD removal conditions. Furthermore conventional Fenton process was able to achieve slightly over an 80% COD removal from a 'young' leachate, while for 'old' and 'mixed' leachates was close to a 70%. The main advantage showed by the photo-assisted Fenton treatment of landfill leachate was that it consumed 32 times less iron and produced 25 times less sludge volume yielding the same COD removal results than a conventional Fenton treatment.

  11. Degradação de poluentes emergentes por processos Fenton e foto-Fenton

    Directory of Open Access Journals (Sweden)

    Marco A. Benedetti Durigan

    2012-01-01

    Full Text Available A continuous photochemical treatment system was developed for aiming the treatment of aqueous solutions containing relevant micro-pollutants (microcystin-LR, sulfamethoxazole and 17-b estradiol. The continuous photo-Fenton process provided high degradation efficiency. However, contact time between samples and the irradiated region is short relative to total treatment time, indicating that observed changes are predominantly due to the Fenton process. Higher degradation efficiency was observed in systems operated using two treatment cycles, the first involving a batch Fenton process and the second a continuous photo-Fenton treatment.

  12. Application of Fenton-like oxidation as pre-treatment for carbamazepine biodegradation

    OpenAIRE

    Monsalvo, VM.; Pedro, ZM. de; M. Muñoz; Casas, JA; Mohedano, AF.; Rodríguez, JJ

    2015-01-01

    Degradation of carbamazepine (CBZ) upon Fenton-like oxidation has been investigated analyzing the effect of H2O2 dose and temperature at a very low catalyst concentration (2mgL-1 of Fe3+). Fenton-like oxidation allowed complete conversion of CBZ, the oxidation rate depending on the amount of H2O2 used. The addition of the theoretical stoichiometric amount of H2O2 led to the complete conversion of CBZ in 1h reaction time. The reduction of the H2O2 initial concentration down to 10% of the stoic...

  13. The Effect and its Influence Factors of the Fenton Process on the Old Landfill Leachate

    OpenAIRE

    Long Tengrui; Anas Al-Harbawi; Zhai Jun; Lin Ming Bo

    2007-01-01

    An experiment study on landfill leachate treatment using Fenton's reagents has been introduced. The effect of operating conditions such as reaction time, pH, H2O2 to Fe(II) ratio (W/W) and temperature on the efficacy of Fenton process was investigated. The monitored sample taken from the Chang Sheng bridge landfill site in Chongqing city-China, has its concentrations of COD, BOD5 and NH3-N about 1500, 75 and 920 mg L-1, respectively. The oxidation of organic materials in the leachate i...

  14. Decolorizing textile wastewater with Fenton's reagent electrogenerated with a solar photovoltaic cell.

    Science.gov (United States)

    Figueroa, Sandra; Vázquez, Leticia; Alvarez-Gallegos, A

    2009-02-01

    In this work it is demonstrated that Fenton's reagent can be electroproduced with abundant and cheap feedstock: oxygen saturated wastewater and solar energy. Experiments were carried out in a divided electrochemical flow cell using two electrodes: a three dimensional reticulated vitreous carbon cathode and stainless steel anode. Fenton's reagent is produced by oxygen reduction on the cathode in the presence of 1mM Fe(2+). The influence of electrolyte nature and its concentration and potential difference on the current efficiency, as well as the rate of Fenton's reagent electroproduction is discussed and it is concluded that over this extended range of conditions the current efficiency, for Fenton's reagent production, fell within the range 50-70%. It is possible to electroproduce a stoichiometric amount of Fenton reagent for the oxidation of 0.061mM Reactive Black 5 (in tap water+0.05M Na(2)SO(4), approximately pH 2.8). Similar results were obtained for solutions containing 0.1mM Acid Green 25. Some practical applications in the field of water treatment are included. The energy required for drive electrochemical reaction is supplied to the flow cell by means of a commercial solar panel. PMID:18977506

  15. Treatment of oilfield wastewater by Fenton's process.

    Science.gov (United States)

    Gao, Y X; Yang, M; Zhang, Y; Hu, J Y

    2004-01-01

    A combination of coagulation and Fenton's process was used for the removal of total oxygen carbon (TOC) from oilfield wastewater. Compared with aluminium sulfate, ferric coagulant had better TOC removal efficiency at the same mass dosage. In Fenton's process, the effect of H2O2 and Fe2+ dose on the removal of TOC was studied. The optimum conditions required for TOC removal were an Fe3+ concentration of 40-50 mg/L, an H2O2 dose of 50 mmol/L and an Fe2+ concentration of 1.0 mmol/L. GC-MS chromatographic analysis indicated that most of the alkyl hydrocarbons of carbon numbers < 21 were removed in the first minute of Fenton's process mainly through adsorption. Alkyl hydrocarbons and phenols were oxidized almost completely following 120 min of treatment. The pathway of newly formed intermediates in Fenton's process was proposed on the basis of the GC/MS chromatogram. PMID:15077956

  16. AN ADVANCED OXIDATION PROCESS : FENTON PROCESS

    OpenAIRE

    Engin GÜRTEKİN; Nusret ŞEKERDAĞ

    2008-01-01

    Biological wastewater treatment is not effective treatment method if raw wastewater contains toxic and refractory organics. Advanced oxidation processes are applied before or after biological treatment for the detoxification and reclamation of this kind of wastewaters. The advanced oxidation processes are based on the formation of powerful hydroxyl radicals. Among advanced oxidation processes Fenton process is one of the most promising methods. Because application of Fenton process is simple ...

  17. Fenton-Like Oxidation of Malachite Green Solutions: Kinetic and Thermodynamic Study

    Directory of Open Access Journals (Sweden)

    Saeedeh Hashemian

    2013-01-01

    Full Text Available Oxidation by Fenton-like (Fe3+/H2O2 reactions is proven to be an economically feasible process for destruction of a variety of hazardous pollutants in wastewater. In this study, the degradation and mineralization of malachite green dye are reported using Fenton-like reaction. The effects of different parameters like pH of the solution, the initial concentrations of Fe3+, H2O2, and dye, temperature, and added electrolytes (Cl− and on the oxidation of the dye were investigated. Optimized condition was determined. The efficiency of 95.5% degradation of MAG after 15 minutes of reaction at pH 3 was obtained. TOC removal indicates partial and insignificant mineralization of malachite green dye. The results of experiments showed that degradation of malachite green dye in Fenton-like oxidation process can be described with a pseudo-second-order kinetic model. The thermodynamic constants of the Fenton oxidation process were evaluated. The results implied that the oxidation process was feasible, spontaneous, and endothermic. The results will be useful for designing the treatment systems of various dye-containing wastewaters.

  18. Exploitation of Fenton and Fenton-like reagents as alternative conditioners for alum sludge conditioning

    Institute of Scientific and Technical Information of China (English)

    Maha A. Tony; Y. Q. Zhao; Aghareed M. Tayeb

    2009-01-01

    The use of Fenton's reagent (Fe2+/H2O2) and Fenton-like reagents containing transition metals of Cu(II), Zn(II), Co(II), and Mn(II) for an alum sludge conditioning to improve its dewaterability was investigated in this study. The results obtained were compared with those obtained from conditioning the same alum sludge using cationic and anionic polymers. Experimental results show that Fenton's reagent was the best among the Fenton and Fenton-like reagents for the alum sludge conditioning. A considerable effectiveness of capillary suction time (CST) reduction efficiency of 47% can be achieved under test conditions of Fe2+/H2O2 = 20/125 mg/gDS (dry solid) and pH = 6.0. The observation of floc-like particles after Fenton's reagent conditioning of alum sludge suggests that the mechanism of Fenton's reagent conditioning was different with that of polymer conditioning. In spite of the less efficiency in the CST reduction of Fenton's reagent in alum sludge conditioning compared with that of polymer conditioning, is less than that of polymer conditioning.[b1] This study provided an example of proactive treatment engineering, which is aimed at seeking a safe alternative to the use of polymers in sludge conditioning towards achieving a more sustainable sludge management strategy.

  19. Electro-Fenton degradation of antimicrobials triclosan and triclocarban

    Energy Technology Data Exchange (ETDEWEB)

    Sires, Ignasi [Laboratori d' Electroquimica dels Materials i del Medi Ambient, Departament de Quimica Fisica, Facultat de Quimica, Universitat de Barcelona, Marti i Franques 1-11, 08028 Barcelona (Spain); Oturan, Nihal [Universite de Marne la Vallee, Laboratoire des Geomateriaux et Geologie de l' Ingenieur, 5 Boulevard Descartes, Champs-sur-Marne, 77454 Marne-la-Vallee Cedex 2 (France); Oturan, Mehmet A. [Universite de Marne la Vallee, Laboratoire des Geomateriaux et Geologie de l' Ingenieur, 5 Boulevard Descartes, Champs-sur-Marne, 77454 Marne-la-Vallee Cedex 2 (France); Rodriguez, Rosa Maria [Laboratori d' Electroquimica dels Materials i del Medi Ambient, Departament de Quimica Fisica, Facultat de Quimica, Universitat de Barcelona, Marti i Franques 1-11, 08028 Barcelona (Spain); Garrido, Jose Antonio [Laboratori d' Electroquimica dels Materials i del Medi Ambient, Departament de Quimica Fisica, Facultat de Quimica, Universitat de Barcelona, Marti i Franques 1-11, 08028 Barcelona (Spain); Brillas, Enric [Laboratori d' Electroquimica dels Materials i del Medi Ambient, Departament de Quimica Fisica, Facultat de Quimica, Universitat de Barcelona, Marti i Franques 1-11, 08028 Barcelona (Spain)]. E-mail: brillas@ub.edu

    2007-05-05

    The antimicrobials triclosan (2,4,4'-trichloro-2'-hydroxydiphenyl ether) and triclocarban (N-(4-chlorophenyl)-N'-(3,4-dichlorophenyl)urea) have been degraded by four electro-Fenton systems using undivided electrolytic cells with a Pt or boron-doped diamond (BDD) anode and a carbon felt or O{sub 2} diffusion cathode. The main oxidant is hydroxyl radical ({center_dot}OH) produced both on the anode surface from water oxidation and in the medium by Fenton's reaction, which takes place between electrogenerated H{sub 2}O{sub 2} and Fe{sup 2+} coming from cathodic reduction of O{sub 2} and Fe{sup 3+}, respectively. Triclosan from saturated aqueous solutions of pH 3.0 is completely removed in all cells, decreasing its decay rate in the order: Pt/carbon felt > BDD/carbon felt > Pt/O{sub 2} diffusion > BDD/O{sub 2} diffusion, in agreement with their {center_dot}OH generation ability from Fenton's reaction. Glyoxylic, maleic and oxalic acids are identified as aliphatic intermediates. Complexes between oxalic acid and iron ions persist largely in solution, although Fe{sup 2+}-oxalato complexes are mineralized by {center_dot}OH in the medium and Fe{sup 3+}-oxalato complexes are destroyed by {center_dot}OH on BDD. Analogous treatments of more concentrated triclosan solutions using a 20:80 (v/v) acetonitrile/water mixture as solvent evidence the role of hydroxyl radicals along the degradation. In this hydroorganic medium hydroxylated derivatives such as 2,4-dichlorophenol, 4-chlorocatechol, chlorohydroquinone and chloro-p-benzoquinone, and carboxylic acids such as maleic, oxalic, formic and acetic acids are detected as products. Complete destruction of iron-oxalato complexes and released Cl{sup -} ion involves some oxidizing species coming from parallel acetonitrile oxidation. The same electro-Fenton systems also yield the overall removal of triclocarban in acetonitrile/water mixtures, giving rise to urea, hydroquinone, chlorohydroquinone, 1-chloro-4

  20. Phenanthrene and pyrene oxidation in contaminated soils using Fenton's reagent

    International Nuclear Information System (INIS)

    Fenton's reagent has shown its applicability to oxidizing these biorefractory organic contaminants. The purpose of this contribution was to investigate the influence of operating parameters on the process efficiency for soil highly contaminated by PAHs. Five variables were selected: pH, reaction time, UV irradiation, hydrogen peroxide concentration and Fe (II) amendment. Their effects on the oxidation of (i) phenanthrene and on (ii) phenanthrene and pyrene present in freshly contaminated soil samples were studied through batch reactor experiments following factorial designs. For phenanthrene oxidation run with a soil contaminated at 700 mg kg-1, one set of variables enabled us to reach a residual concentration lower than 40 mg kg-1 (Dutch legislation threshold). The most important factor was the reaction time, followed at a certain distance by UV irradiation, Fe (II), H2O2 concentration and pH, this last variable being the least significant. The possibility of operating without pH adjustment is of importance in the treatment at the field scale. This shows the feasibility of photo-Fenton-like oxidation for the treatment of soil highly contaminated with PAH and the relative importance of the process variables

  1. Treatment of mature landfill leachate by chemical precipitation and Fenton advanced oxidation process

    Directory of Open Access Journals (Sweden)

    Nemat Alah Jaafarzadeh Haghighi Fard

    2016-03-01

    Full Text Available Background: Mature landfill leachate is a complicated mixture which is resistant to biological treatment processes. The treatment of mature landfill leachate by struvite precipitation and Fenton oxidation was the main objective of the current research. Methods: Struvite with the phosphate/ammonia/magnesium molar ratio of 1/1/1.05 was considered during all experiments. Five initial pHs of 3, 4, 5, 6, and 7, four different H2O2/Fe mass ratios of 50, 100, 200, and 400, and reaction times of 20, 40, 80, 120, and 160 minutes were examined for the Fenton oxidation process. Results: A leachate sample with average chemical oxygen demand (COD, BOD5, and NH4 concentrations of 7350, 2220, and 2280 mg L-1, respectively, and a BOD5/COD ratio of 0.3 was introduced to the chemical precipitation unit. An NH4 removal efficiency of 87% was obtained at pH 8.5 for struvite precipitation. Under optimum conditions of Fenton oxidation, including pH 3, an H2O2/Fe2+ mass ratio of 200, and a reaction time of 160 min, more than 95% COD and BOD5 removal was observed. Conclusion: Struvite precipitation and Fenton oxidation are reliable and efficient alternatives for mature landfill treatment.

  2. Oxidation of AOX and organic compounds in pharmaceutical wastewater in RSM-optimized-Fenton system.

    Science.gov (United States)

    Xie, Yawei; Chen, Lujun; Liu, Rui

    2016-07-01

    Adsorbable organic halogens (AOX) and total organic carbon (TOC) removal efficiencies in pharmaceutical wastewater treated by Fenton process under response surface methodology (RSM) optimized conditions were studied. High regression coefficient value R(2) (R(2) = 0.9680, 0.9040 for AOX and TOC removal efficiency, respectively) and low value coefficient of variation (2.21%, 2.04% for AOX and TOC, respectively) of the quadratic model indicated that the model was accurate in predicting the experimental results. The desirability function was used to optimize AOX and TOC removal efficiencies simultaneously. The optimal pH, Fe(2+) concentration, molar ratio of H2O2/Fe(2+) and reaction time were found to be 3.3, 19.05 mM, 20.16 and 2.2 h, respectively, and 91.78% AOX and 75.01% TOC were removed under these conditions, which was validated. Furthermore, gas chromatography-mass spectrometer (GC-MS) results revealed that 28 out of 33 kinds of organic compounds, including 11 kinds of AOX were completely removed by the Fenton process while one new AOX compound, 4,5,6,7-tetrachlorophthalide, was produced which was the result of the carbonyl of 4,5,6,7-tetrachloro-1,3-isobenzofurandione being attacked in the Fenton reaction. These results indicated that analysis of organics was important since new AOX compounds could be produced in Fenton process despite the value of AOX decreasing. PMID:27115846

  3. Exploitation of Fenton and Fenton-like reagents as alternative conditioners for alum sludge conditioning

    OpenAIRE

    Tony, Maha A.; Zhao, Y. Q.; Tayeb, Aghareed M.

    2009-01-01

    The use of Fenton’s reagent (Fe2+/H2O2) and Fenton-like reagents containing transition metals of Cu(II), Zn(II), Co(II) and Mn(II) for an alum sludge conditioning to improve its dewaterability was investigated in this study. The results obtained were compared with those obtained from conditioning the same alum sludge using cationic and anionic polymers. Experimental results show that Fenton’s reagent was the best among the Fenton and Fenton-like reagents for the alum sludge conditioning. A co...

  4. Use of Enzymatic Bio-Fenton as a New Approach in Decolorization of Malachite Green

    Directory of Open Access Journals (Sweden)

    Afzal Karimi

    2012-01-01

    Full Text Available An enzymatic reaction using glucose oxidase was applied for in situ production of hydrogen peroxide for use in simultaneously Fenton's reaction in decolorization of malachite green. It was found that decolorization rate increased by increasing of glucose concentration from 0.2 g/L to 1.5 g/L. Decolorization rate showed different behaviors versus temperature changes. Initial rate of decolorization process was increased by increasing of temperature; after 30 minutes, especially at temperatures above 30°C, the decolorization rate was gradually reduced. The pH value in the reaction media was decreased from natural to about pH=3 which had synergic effect on the Fenton process by stabilizing of Fe2+ ions.

  5. Treatment of Actual Chemical Wastewater by a Heterogeneous Fenton Process Using Natural Pyrite.

    Science.gov (United States)

    Sun, Liang; Li, Yan; Li, Aimin

    2015-11-01

    Wastewater from chemical plants has remarkable antibiotic effects on the microorganisms in traditional biological treatment processes. An enhanced Fenton system catalyzed by natural pyrite was developed to degrade this kind of wastewater. Approximately 30% chemical oxygen demand (COD) was removed within 120 min when 50 mmol/L H₂O₂ and 10 g/L natural pyrite were used at initial pH from 1.8 to 7. A BOD₅/COD enhancement efficiency of 210% and an acute biotoxicity removal efficiency of 84% were achieved. The COD removal efficiency was less sensitive to initial pH than was the classic Fenton process. Excessive amounts of pyrite and H₂O₂ did not negatively affect the pyrite Fenton system. The amount of aniline generated indicated that nitrobenzene reduction by pyrite was promoted using a low initial concentration of H₂O₂ (<5 mmol/L). Fluorescence excitation emission matrix analyses illustrated that H₂O₂ facilitated the reduction by natural pyrite of organic molecules containing an electron-withdrawing group to electron-donating group. Thus, the Fenton-like process catalyzed by pyrite can remediate wastewater containing organic pollutants under mild reaction conditions and provide an alternative environmentally friendly method by which to reuse natural pyrite. PMID:26516893

  6. Effects of inorganic anions on carbon isotope fractionation during Fenton-like degradation of trichloroethene.

    Science.gov (United States)

    Liu, Yunde; Zhou, Aiguo; Gan, Yiqun; Li, Xiaoqian

    2016-05-01

    Understanding the magnitude and variability in isotope fractionation with respect to specific processes is crucial to the application of stable isotopic analysis as a tool to infer and quantify transformation processes. The variability of carbon isotope fractionation during Fenton-like degradation of trichloroethene (TCE) in the presence of different inorganic ions (nitrate, sulfate, and chloride), was investigated to evaluate the potential effects of inorganic anions on carbon isotope enrichment factor (ε value). A comparison of ε values obtained in deionized water, nitrate solution, and sulfate solution demonstrated that the ε values were identical and not affected by the presence of nitrate and sulfate. In the presence of chloride, however, the ε values (ranging from -6.3±0.8 to 10±1.3‰) were variable and depended on the chloride concentration, indicating that chloride could significantly affect carbon isotope fractionation during Fenton-like degradation of TCE. Thus, caution should be exercised in selecting appropriate ε values for the field application of stable isotope analysis, as various chloride concentrations may be present due to naturally present or introduced with pH adjustment and iron salts during Fenton-like remediation. Furthermore, the effects of chloride on carbon isotope fractionation may be able to provide new insights about reaction mechanisms of Fenton-like processes. PMID:26835895

  7. Treatability assessment of polycyclic aromatic hydrocarbons contaminated marine sediments using permanganate, persulfate and Fenton oxidation processes.

    Science.gov (United States)

    Shih, Yu-Jen; Binh, Nguyen Thanh; Chen, Chiu-Wen; Chen, Chih-Feng; Dong, Cheng-Di

    2016-05-01

    Various chemical oxidation techniques, such as potassium permanganate (KMnO4), sodium persulfate (Na2S2O8), Fenton (H2O2/Fe(2+)), and the modified persulfate and Fenton reagents (activated by ferrous complexes), were carried out to treat marine sediments that were contaminated with polycyclic aromatic hydrocarbons (PAHs) and dredged from Kaohsiung Harbor in Taiwan. Experimental results revealed that KMnO4 was the most effective of the tested oxidants in PAH degradation. Owing to the high organic matter content in the sediment that reduced the efficiencies of Na2S2O8 and regular Fenton reactions, a large excess of oxidant was required. Nevertheless, KH2PO4, Na4P2O7 and four chelating agents (EDTA, sodium citrate, oxalic acid, and sodium oxalate) were utilized to stabilize Fe(II) in activating the Na2S2O8 and Fenton oxidations, while Fe(II)-citrate remarkably promoted the PAH degradation. Increasing the molecular weight and number of rings of PAH did not affect the overall removal efficiencies. The correlation between the effectiveness of the oxidation processes and the physicochemical properties of individual PAH was statistically analyzed. The data implied that the reactivity of PAH (electron affinity and ionization potential) affected its treatability more than did its hydrophobicity (Kow, Koc and Sw), particularly using experimental conditions under which PAHs could be effectively oxidized. PMID:26915591

  8. Photo-Fenton-like treatment of K-acid: assessment of treatability, toxicity and oxidation products.

    Science.gov (United States)

    Olmez-Hanci, Tugba; Arslan-Alaton, Idil; Gelegen, Ozlem

    2014-01-01

    Photo-Fenton-like treatment of the commercially important naphthalene sulphonate K-acid (2-naphthylamine-3,6,8-trisulphonic acid) was investigated using UV-C, UV-A and visible light irradiation. Changes in toxicity patterns were followed by the Vibrio fischeri bioassay. Rapid and complete degradation of K-acid accompanied with nearly complete oxidation and mineralization rates (>90%) were achieved for all studied irradiation types. On the other hand, detoxification was rather limited and did not change significantly during photo-Fenton-like treatment. Several oxidation products could be identified via liquid chromatograph-mass spectrometer analyses, such as desulphonated and hydroxylated naphthalene derivatives, quinones, and ring-opening as well as dimerization products. Photo-Fenton-like treatment of K-acid with UV-C, UV-A and visible light irradiation occurred through a series of hydroxylation and desulphonation reactions, followed by ring cleavage. A common degradation pathway for photo-Fenton-like treatment of K-acid using different irradiation types was proposed. PMID:25259495

  9. Review of iron-free Fenton-like systems for activating H2O2 in advanced oxidation processes

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Elements with multiple redox states efficiently decompose H2O2 at neutral pH. • Activation of H2O2 is entirely governed by solution pH and catalyst composition. • Metal leaching and toxicity is an important factor for practical applications. • Iron-free Fenton systems work only in specialized reaction conditions. - Abstract: Iron-catalyzed hydrogen peroxide decomposition for in situ generation of hydroxyl radicals (HO• ) has been extensively developed as advanced oxidation processes (AOPs) for environmental applications. A variety of catalytic iron species constituting metal salts (in Fe2+ or Fe3+ form), metal oxides (e.g., Fe2O3, Fe3O4), and zero-valent metal (Fe0) have been exploited for chemical (classical Fenton), photochemical (photo-Fenton) and electrochemical (electro-Fenton) degradation pathways. However, the requirement of strict acidic conditions to prevent iron precipitation still remains the bottleneck for iron-based AOPs. In this article, we present a thorough review of alternative non-iron Fenton catalysts and their reactivity towards hydrogen peroxide activation. Elements with multiple redox states (like chromium, cerium, copper, cobalt, manganese and ruthenium) all directly decompose H2O2 into HO• through conventional Fenton-like pathways. The in situ formation of H2O2 and decomposition into HO• can be also achieved using electron transfer mechanism in zero-valent aluminum/O2 system. Although these Fenton systems (except aluminum) work efficiently even at neutral pH, the H2O2 activation mechanism is very specific to the nature of the catalyst and critically depends on its composition. This review describes in detail the complex mechanisms and emphasizes on practical limitations influencing their environmental applications

  10. Acetaminophen degradation by electro-Fenton and photoelectro-Fenton using a double cathode electrochemical cell

    International Nuclear Information System (INIS)

    Highlights: ► The electro-Fenton reactor using a double cathode electrochemical cell was applied. ► The initial Fe2+ concentration was the most significant parameter for the acetaminophen degradation. ► Thirteen intermediates were identified and a degradation pathway was proposed. - Abstract: Acetaminophen is a widely used drug worldwide and is one of the most frequently detected in bodies of water making it a high priority trace pollutant. This study investigated the applicability of the electro-Fenton and photoelectro-Fenton processes using a double cathode electrochemical cell in the treatment of acetaminophen containing wastewater. The Box–Behnken design was used to determine the effects of initial Fe2+ and H2O2 concentrations and applied current density. Results showed that all parameters positively affected the degradation efficiency of acetaminophen with the initial Fe2+ concentration being the most significant parameter for both processes. The acetaminophen removal efficiency for electro-Fenton was 98% and chemical oxygen demand (COD) removal of 43% while a 97% acetaminophen removal and 42% COD removal were observed for the photoelectro-Fenton method operated at optimum conditions. The electro-Fenton process was only able to obtain 19% total organic carbon (TOC) removal while the photoelectro-Fenton process obtained 20%. Due to negligible difference between the treatment efficiencies of the two processes, the electro-Fenton method was proven to be more economically advantageous. The models obtained from the study were applicable to a wide range of acetaminophen concentrations and can be used in scale-ups. Thirteen different types of intermediates were identified and a degradation pathway was proposed.

  11. Acetaminophen degradation by electro-Fenton and photoelectro-Fenton using a double cathode electrochemical cell

    Energy Technology Data Exchange (ETDEWEB)

    Luna, Mark Daniel G. de [Department of Chemical Engineering, University of the Philippines, 1011 Diliman, Quezon City (Philippines); Environmental Engineering Graduate Program, University of the Philippines, 1011 Diliman, Quezon City (Philippines); Veciana, Mersabel L. [Environmental Engineering Graduate Program, University of the Philippines, 1011 Diliman, Quezon City (Philippines); Su, Chia-Chi [Department of Environmental Resources Management, Chia Nan University of Pharmacy and Science, Tainan 717, Taiwan (China); Lu, Ming-Chun, E-mail: mmclu@mail.chan.edu.tw [Department of Environmental Resources Management, Chia Nan University of Pharmacy and Science, Tainan 717, Taiwan (China)

    2012-05-30

    Highlights: Black-Right-Pointing-Pointer The electro-Fenton reactor using a double cathode electrochemical cell was applied. Black-Right-Pointing-Pointer The initial Fe{sup 2+} concentration was the most significant parameter for the acetaminophen degradation. Black-Right-Pointing-Pointer Thirteen intermediates were identified and a degradation pathway was proposed. - Abstract: Acetaminophen is a widely used drug worldwide and is one of the most frequently detected in bodies of water making it a high priority trace pollutant. This study investigated the applicability of the electro-Fenton and photoelectro-Fenton processes using a double cathode electrochemical cell in the treatment of acetaminophen containing wastewater. The Box-Behnken design was used to determine the effects of initial Fe{sup 2+} and H{sub 2}O{sub 2} concentrations and applied current density. Results showed that all parameters positively affected the degradation efficiency of acetaminophen with the initial Fe{sup 2+} concentration being the most significant parameter for both processes. The acetaminophen removal efficiency for electro-Fenton was 98% and chemical oxygen demand (COD) removal of 43% while a 97% acetaminophen removal and 42% COD removal were observed for the photoelectro-Fenton method operated at optimum conditions. The electro-Fenton process was only able to obtain 19% total organic carbon (TOC) removal while the photoelectro-Fenton process obtained 20%. Due to negligible difference between the treatment efficiencies of the two processes, the electro-Fenton method was proven to be more economically advantageous. The models obtained from the study were applicable to a wide range of acetaminophen concentrations and can be used in scale-ups. Thirteen different types of intermediates were identified and a degradation pathway was proposed.

  12. Degradação de poluentes emergentes por processos Fenton e foto-Fenton

    OpenAIRE

    Marco A. Benedetti Durigan; Sergio Renato Vaz; Patricio Peralta-Zamora

    2012-01-01

    A continuous photochemical treatment system was developed for aiming the treatment of aqueous solutions containing relevant micro-pollutants (microcystin-LR, sulfamethoxazole and 17-b estradiol). The continuous photo-Fenton process provided high degradation efficiency. However, contact time between samples and the irradiated region is short relative to total treatment time, indicating that observed changes are predominantly due to the Fenton process. Higher degradation efficiency was observed...

  13. Removal of benzene from wastewater via Fenton pre-treatment followed by enzyme catalyzed polymerization.

    Science.gov (United States)

    Saha, Beeta; Taylor, K E; Bewtra, J K; Biswas, N

    2011-01-01

    This study investigated the feasibility of a two-step process for the removal of benzene from buffered synthetic wastewater. Benzene is outside the scope of enzymatic removal. In order to remove it from wastewater using enzyme, its pretreatment by modified Fenton reaction was employed to generate the corresponding phenolic compounds. In the first phase, the optimum pH, H2O2 and Fe2+ concentrations and reaction time for the Fenton reaction were determined to maximize the conversion of benzene to phenolic compounds without causing significant mineralization. The pretreatment process was followed by oxidative polymerization of the phenolic compounds catalyzed by a laccase from Trametes villosa. Factors of interest for the three-hour enzymatic treatment were pH and laccase concentration. Under optimum Fenton reaction conditions, 80% conversion of the initial benzene concentration was achieved, giving a mixture containing oxidative dimerization product (biphenyl) and hydroxylation products (phenol, catechol, resorcinol, benzoquinone and hydroquinone). Enzymatic removal of biphenyl and benzoquinone was not possible but 2.5 U/mL laccase was successful in removal of the rest of the phenolic PMID:21866766

  14. Industrial detergent wastewater treatment via fenton reagent

    International Nuclear Information System (INIS)

    Production of detergent can generates wastewater containing an organic matter with will consume an oxidation demand, surfactants, suspended solids, fat and oil. Besides, sulfate concentration is high in the most detergent plant effluent because of the sulphonation process that has physiological and toxic effects on marine organisms. Therefore, a research must be conducted to find the solution for this problem. The feasibility of Fentons reagent to treat detergent waste was investigated in this study. The sample of detergent wastewater was taken from FPG Oleo chemicals Sdn. Bhd. This experiment studied the effect of temperature towards the feasibility of Fentons reagent process besides the dosage between hydrogen peroxide (H2O2) and ferrous ion (Fe2+) in the reagent. While, evaluated efficiency of Fentons reagent in term of chemical oxygen demand (COD), total suspended solid (TSS) and the turbidity reduction within the experimental design. The result found that overall removal was achieved until 96.2 % in term of COD, 98.1 % in term of TSS and 99.6 % in term of turbidity using Fentons reagent process. Besides, also found that this process is optimum at temperature 35 degree Celsius are able to achieve the Standard A of Parameter Limit of Effluent of Standard A and Standard B were outlined by Department of Environment Malaysia (DOE) based on Environment Quality Act 1974. (author)

  15. Impact of Fenton and ozone on oxidation of wastewater containing nitroaromatic compounds

    Institute of Scientific and Technical Information of China (English)

    Fares Al Momani; Mo'ayyad Shawaqfah; Ahmad Shawaqfeh; Mohammad Al-Shannag

    2008-01-01

    Fenton and ozone treatment was investigated at laboratory scale for the degradation of aqueous solutions of nitrobenzene (NB).Effects of reactants concentration (O3,H2O2,and Fe(II)),temperature,and pH on NB degradation were monitored.Reaction kinetic of these processes was also assessed.A rapid reaction took place for Fenton process at higher initial concentration of H2O2,higher temperatures,and more acidic conditions(pH 3).Similarly, ozonation reaction exhibited rapid rates for higher ozone dose,higher temperatures,and more basic conditions(pH 11).Complete NB degradation in 65 min Was achieved using Fenton process.The conditions of complete elimination of 100 mg/L of initial NB concentration,were 250 mg/L of H2O2 concentration,pH 3,and 10 mg/L of Fe(Ⅱ) concentration.Under these conditions,55% organic carbon elimination Was achieved.Total organic carbon mineralization Was attained in 240 min reaction time by Fenton process with 900 mg/L of H2O2 concentration,and 30 mg/L of Fe(II) concentration.Fenton reaction showed a pseudo-first order kinetic;the reaction rate constant Was ranged from 0.0226 to 0.0658 min-1.Complete NB degradation wag also achieyed for an ozone dose of the order of 2.5 g/L.The ozonation Was studied at different ozone doses.different initial pH(7-11)and at difierent temperatures(15-35℃).NB ozonation kinetic Was represented by a bi-molecular kinetic model which was reduced to pseudo-first order kinetic.The pseudo-first order reaction rate constant was determined to increase at 20℃ from 0.004 to 0.020 min-1 as the used ozone increased from 0.4 to 1.9g/L.

  16. Heterogeneous photo-assisted Fenton catalytic removal of tetracycline using Fe-Ce pillared bentonite

    Institute of Scientific and Technical Information of China (English)

    张亚平; 贾成光; 彭然; 马丰; 欧光南

    2014-01-01

    In the present work, a novel heterogeneous photo-Fenton catalyst was prepared by iron and cerium pillared bentonite. The catalyst Fe-Ce/bentonite was characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), Brunauer-Emmett-Teller (BET) and scanning electron microscopy (SEM) methods. It is found that Fe and Ce intercalate into the silicate layers of bentonite successfully. Tetracycline was removed by heterogeneous photo-Fenton reaction using the catalyst in this work. The effects of different reaction systems, hydrogen peroxide concentration, initial pH, catalyst dosage, UV power and introduction of different anions on degradation were investigated in details. The stability of catalyst was investigated through recycling experiment. The results show that removal rate of tetracycline is 98.13%under the conditions of 15 mmol/L H2O2, 0.50 g/L catalyst dosage, initial pH 3.0, 11 W UV lamp power and 60 min reaction time. However, the removal rate decreases after adding some anions. The hydroxyl radical plays an important role in heterogeneous photo-assisted Fenton degradation of tetracycline. The catalyst is very stable and can be recycled many times.

  17. Pyrite nanoparticles as a Fenton-like reagent for in situ remediation of organic pollutants

    Directory of Open Access Journals (Sweden)

    Carolina Gil-Lozano

    2014-06-01

    Full Text Available The Fenton reaction is the most widely used advanced oxidation process (AOP for wastewater treatment. This study reports on the use of pyrite nanoparticles and microparticles as Fenton reagents for the oxidative degradation of copper phthalocyanine (CuPc as a representative contaminant. Upon oxidative dissolution in water, pyrite (FeS2 particles can generate H2O2 at their surface while simultaneously promoting recycling of Fe3+ into Fe2+ and vice versa. Pyrite nanoparticles were synthesized by the hot injection method. The use of a high concentration of precursors gave individual nanoparticles (diameter: 20 nm with broader crystallinity at the outer interfaces, providing a greater number of surface defects, which is advantageous for generating H2O2. Batch reactions were run to monitor the kinetics of CuPc degradation in real time and the amount of H2O2. A markedly greater degradation of CuPc was achieved with nanoparticles as compared to microparticles: at low loadings (0.08 mg/L and 20 h reaction time, the former enabled 60% CuPc removal, whereas the latter enabled only 7% removal. These results confirm that the use of low concentrations of synthetic nanoparticles can be a cost effective alternative to conventional Fenton procedures for use in wastewater treatment, avoiding the potential risks caused by the release of heavy metals upon dissolution of natural pyrites.

  18. Advanced treatment of pharmaceutical wastewater by Fenton reagent oxidation process

    Directory of Open Access Journals (Sweden)

    Yanan YANG

    2015-12-01

    Full Text Available Avermectin-salinomycin waster is hard to be further biodegraded after treated by anaerobic-aerobiotic process, so Fenton oxidation process is studied for its advanced treatment. Influencing factors of pH, reaction time, H2O2 dosage and H2O2/Fe2+ on COD removal are investigated, respectively. When pH value is 3.0, the dosage of H2O2 is 1.5 mL/L, and the mole ratio of H2O2/Fe2+ is 5∶1, the effluent COD mass concentrations decreases from 224 to 64.3 mg/L, namely the COD removal efficiency reaches 71.3%.

  19. Photo-Fenton degradation of the insecticide esfenvalerate in aqueous medium using a recirculation flow-through UV photoreactor

    Energy Technology Data Exchange (ETDEWEB)

    Colombo, Renata, E-mail: colombo@iqsc.usp.br [Instituto de Quimica de Sao Carlos, Universidade de Sao Paulo, Caixa Postal 780, 13560-970 Sao Carlos, SP (Brazil); Ferreira, Tanare C.R.; Alves, Suellen A.; Lanza, Marcos R.V. [Instituto de Quimica de Sao Carlos, Universidade de Sao Paulo, Caixa Postal 780, 13560-970 Sao Carlos, SP (Brazil)

    2011-12-30

    Highlights: Black-Right-Pointing-Pointer The photo-Fenton reaction provides an efficient process by which to degrade esfenvalerate in aqueous suspensions. Black-Right-Pointing-Pointer Photo-Fenton oxidation with Fe{sup 3+} is more efficient in degrading esfenvalerate than the Fe{sup 2+}-based reaction. Black-Right-Pointing-Pointer Esfenvalerate was degraded most efficiently by photo-Fenton reaction in the presence of 5 mM Fe{sup 3+} complex and 25 mM hydrogen peroxide at pH 2.5. Black-Right-Pointing-Pointer The degradation of esfenvalerate by photo-Fenton (Fe{sup 3+}) generates organic by-products. Black-Right-Pointing-Pointer Organic compounds present in commercial esfenvalerate-based insecticides affect the degradation process. - Abstract: The aim of the study was to evaluate the efficiencies of photo-Fenton (Fe{sup 2+}) and (Fe{sup 3+}) processes in the degradation of high-concentrations of esfenvalerate (in the form of aqueous emulsion of a commercial formulation) using a recirculation flow-through photoreactor irradiated with UV light from a 15 W lamp (254 nm emission peak). The results obtained using a basic photo-Fenton (Fe{sup 2+}) reaction (esfenvalerate 17 mg L{sup -1}; ferrous sulphate 1 mM; hydrogen peroxide 25 mM; pH 2.5) were compared with those acquired when ferrioxalate (1, 3 or 5 mM) served as the iron source. Degradation of the active component of the commercial formulation was significantly greater, and the rate of oxidation more rapid, using a photo-Fenton (Fe{sup 3+}) process compared with its Fe{sup 2+} counterpart. The most efficient degradation of the insecticide (75% in 180 min) was achieved with a reaction mixture containing 5 mM ferrioxalate. However, under the same experimental conditions, degradation of pure esfenvalerate preceded much faster (99% in 60 min) and was 100% complete within 180 min reaction time.

  20. Using single-chamber microbial fuel cells as renewable power sources of electro-Fenton reactors for organic pollutant treatment

    KAUST Repository

    Zhu, Xiuping

    2013-05-01

    Electro-Fenton reactions can be very effective for organic pollutant degradation, but they typically require non-sustainable electrical power to produce hydrogen peroxide. Two-chamber microbial fuel cells (MFCs) have been proposed for pollutant treatment using Fenton-based reactions, but these types of MFCs have low power densities and require expensive membranes. Here, more efficient dual reactor systems were developed using a single-chamber MFC as a low-voltage power source to simultaneously accomplish H2O2 generation and Fe2+ release for the Fenton reaction. In tests using phenol, 75±2% of the total organic carbon (TOC) was removed in the electro-Fenton reactor in one cycle (22h), and phenol was completely degraded to simple and readily biodegradable organic acids. Compared to previously developed systems based on two-chamber MFCs, the degradation efficiency of organic pollutants was substantially improved. These results demonstrate that this system is an energy-efficient and cost-effective approach for industrial wastewater treatment of certain pollutants. © 2013 Elsevier B.V.

  1. Using single-chamber microbial fuel cells as renewable power sources of electro-Fenton reactors for organic pollutant treatment.

    Science.gov (United States)

    Zhu, Xiuping; Logan, Bruce E

    2013-05-15

    Electro-Fenton reactions can be very effective for organic pollutant degradation, but they typically require non-sustainable electrical power to produce hydrogen peroxide. Two-chamber microbial fuel cells (MFCs) have been proposed for pollutant treatment using Fenton-based reactions, but these types of MFCs have low power densities and require expensive membranes. Here, more efficient dual reactor systems were developed using a single-chamber MFC as a low-voltage power source to simultaneously accomplish H2O2 generation and Fe(2+) release for the Fenton reaction. In tests using phenol, 75 ± 2% of the total organic carbon (TOC) was removed in the electro-Fenton reactor in one cycle (22 h), and phenol was completely degraded to simple and readily biodegradable organic acids. Compared to previously developed systems based on two-chamber MFCs, the degradation efficiency of organic pollutants was substantially improved. These results demonstrate that this system is an energy-efficient and cost-effective approach for industrial wastewater treatment of certain pollutants. PMID:23523911

  2. Optimal Condition of Fenton's Reagent to Enhance the Alcohol Production from Palm Oil Mill Effluent (POME

    Directory of Open Access Journals (Sweden)

    Supawadee Sinnaraprasat

    2011-07-01

    Full Text Available Application of Fenton's reaction for a proper hydrolysis step is an essential and important step in obtaining a higher level of readily biodegradable sugars from palm oil mill effluent (POME for improving the alcohol production by using immobilized Clostridium acetobutylicum. The objective of this research was, therefore, to investigate the optimum condition of Fenton's reaction in terms of COD: H2O2 ratios (w/w and H2O2: Fe2+ ratios (molar ratio used to oxidize carbohydrate and high molecular organic compounds into simple sugars, which are further fermented into alcohol. The experiments were carried out at H2O2: Fe2+ ratios (molar ratios of 5, 10, 20, 30 and 40 and the COD: H2O2 ratios (w/w of 50, 70, 100 and 130 (initial COD about 50,000 mg/L. The total sugar concentrations and organic compounds biodegradability (BOD5/COD ratios were also used for investigating suitable conditions for Fenton's reaction. The concentration of Fenton's reagent at H2O2:Fe2+ and COD:H2O2 ratio of 20 and 130 was identified as the optimum operating condition for the highest simple sugars of about 0.865% and BOD5/COD ratios of 0.539. The alcohol productions were carried out in the continuous stirred tank reactors (CSTR under an anaerobic continuous immobilization system. At a hydraulic retention time of 12 hours and POME pH of 4.8, the maximum total ABE concentration of 495 mg/L and the ABE yield of 0.236 grams of ABE produced/gram of reducing sugars were achieved at the mixed polyvinyl alcohol (PVA and palm oil ash (POA ratio of 10 : 3.

  3. Remediation of polluted soils contaminated with Linear Alkyl Benzenes using Fenton's reagent

    Directory of Open Access Journals (Sweden)

    Douglas do Nascimento Silva

    2005-06-01

    Full Text Available Linear Alkyl Benzenes (LABs are used as insulating oil for electric cables. When it happens a spill, LABs they are basically sorbed in the soil, because, these compounds have high hidrophobicity and low vapor pressure. The conventional methods of treatment of soils are not efficient. The Fenton's reaction (reaction between a solution of iron II and hydrogen peroxide it generates hydroxyl radicals, not selective, and capable of oxidize a great variety of organic compounds. A study was conducted to evaluate the viability of use of the Fenton's reagents to promote the remediation of polluted soils with Linear Alkyl Benzenes. A column was especially projected for these experiments, packed with a sandy and other soil loamy. The pH of the soil was not altered. The obtained results demonstrated the technical viability of the process of injection of the Fenton's reagents for the treatment of polluted areas with LABs.Os Linear Alquilbenzenos (LABs são usados como fluido refrigerante de cabos elétricos. Quando ocorre um vazamento, os LABs ficam basicamente adsorvidos no solo, pois, são compostos bastante hidrofóbicos e com baixa pressão de vapor. Os métodos convencionais de tratamento de solos não são eficientes. A reação de Fenton (solução de ferro II e peróxido de hidrogênio gera radicais hidroxila, não seletivos, e capazes de oxidar uma grande variedade de compostos orgânicos, chegando a mineralização dos mesmos. Neste trabalho foi estudada a viabilidade de utilização dos reagentes de Fenton para promover a remediação de solos contaminados com LABs. Utilizou-se uma coluna especialmente projetada para estes experimentos, empacotada com um solo arenoso e outro argiloso. O pH do solo não foi alterado. Os resultados obtidos demonstram a viabilidade técnica do processo de injeção dos reagentes de Fenton para o tratamento de áreas contaminadas com LABs.

  4. Treatment of Effluent from a Factory of Paints Using Solar Photo-Fenton Process

    Directory of Open Access Journals (Sweden)

    Alam Gustavo Trovó

    2013-01-01

    Full Text Available We evaluated the use of Fenton reactions induced by solar radiation in the treatment of effluent from a factory of paints for buildings, after prior removal of the suspended solids. The increase of H2O2 concentration from 100 to 2500 mg L−1 for a [Fe2+] = 105 mg L−1 contributed to the reduction of DOC, COD, and toxicity. Our best results were achieved using 1600 mg L−1 H2O2, with 90% of DOC and COD removal and a complete removal of the toxicity with respect to Artemia salina. Additionally, through increasing Fe2+ concentration from 15 to 45 mg L−1, the DOC removal rate increased 11 times, remaining almost constant in the range above 45 until 105 mg L−1. Under our best experimental conditions, 80% of DOC removal was achieved after an accumulated dose of 130 kJ m−2 of UVA radiation (82±17 min of solar irradiation under an average UVA irradiance of 34.1±7.3 W m−2, while 40% of DOC removal was reached after 150 min under only thermal Fenton reactions. The results suggest the effectiveness of implementation of solar photo-Fenton process in the decontamination and detoxification of effluents from factories of paints for buildings.

  5. Fenton's Reagent. Innovative Technology Summary Report

    International Nuclear Information System (INIS)

    The Fenton's Reagent DNAPL treatment process is an in situ oxidation method to destroy DNAPLs in groundwater. Residual industrial solvents, primarily Dense Non-Aqueous Phase Liquids (DNAPLs), are currently the most significant barrier to successful completion of most large groundwater and soil cleanup efforts. DNAPL pools and residues slowly dissolve into surrounding groundwater to create large plumes of organic solvent contamination with concentration levels far above regulatory limits

  6. Heterogeneous fenton process using the mineral hematite for the discolouration of a reactive dye solution

    Directory of Open Access Journals (Sweden)

    F. V. F. Araujo

    2011-12-01

    Full Text Available This work reports a study on the heterogeneous Fenton reaction using hematite powder (Fe2O3 in suspension for the discolouration of the reactive dye Drimarene Red X-6BN in aqueous solutions. The efficiency of the process was studied as a function of the experimental conditions: initial pH; H2O2 dose; and hematite powder concentration; all of which showed a strong effect on the reaction kinetics. Under the best experimental conditions: pH = 2.5; H2O2 dose = 800 mg/L; and [Hematite] = 20 g/L, it was possible to remove about 99% of the initial colour in 120 minutes in a batch reaction at 25ºC. The analysis of the kinetic results suggests that the reaction is initiated by heterogeneous generation of free radicals on the hematite surface, but as soluble iron (III and iron (II species are released into the solution during the course of the reaction, a simultaneous homogeneous Fenton reaction step propagates and contributes to the overall reaction.

  7. Study of the Development of Fenton and Fenton Like Oxidation in High Concentration and Non-degradation Organic Wastewater Treatment%Fenton及类Fenton氧化在高浓度难降解有机废水处理中的研究进展

    Institute of Scientific and Technical Information of China (English)

    赖亦桂

    2012-01-01

    随着工业的迅速发展,越来越多的有机物被广泛运用于工业生产,高浓度难降解的有机废水成为工业水处理的一个难点。阐述了Fenton试剂及光助Fenton、电Fenton以及超声Fenton氧化法处理有机废水的特性,概述了羟基自由基(·OH)的产生机理,对Fenton试剂及类Fenton试剂在有机废水处理上的应用状况进行了总结。%With the rapid development of industry,more and more organics were widely utilized in industry,high concentration and non-degradation organic wastewater became to be a difficult point in industrial water conditioning.Expounded the features of organic wastewater treated with Fenton reagent,Photo-Fenton,Electro-Fenton,US-Fenton reagent;summarized the produced mechanism of ·OH and applied status of organic wastewater treated with Fenton and Fenton Like Reaction.

  8. Treatment of Color Filter Wastewater by Fresnel Lens Enhanced Solar Photo-Fenton Process

    OpenAIRE

    Wen-shiuh Kuo; Chia-ling Wu

    2012-01-01

    Treatment of color filter wastewater using solar photo-Fenton process enhanced by high-concentrating Fresnel lens was investigated in this paper. Optimal reaction conditions based on response surface methodology (RSM) were established as under an initial pH of 5, a [H2O2]0/COD0 ratio of 1~1.35 and a [H2O2]0/[Fe2+]0 ratio of 15 for a reaction time of 60 min, which could reach a readily biodegradable level, that is, the biodegradability (BOD5/COD) of wastewater was more than 0.3. With the assis...

  9. Evaluation of the resin oxidation process using Fenton's reagent

    International Nuclear Information System (INIS)

    The ion exchange resin is considered radioactive waste after its final useful life in nuclear reactors. Usually, this type of waste is treated with the immobilization in cement Portland, in order to form a solid monolithic matrix, reducing the possibility of radionuclides release in to environment. Because of the characteristic of expansion and contraction of the resins in presence of water, its incorporation in the common Portland cement is limited in 10% in direct immobilization, causing high costs in the final product. A pre-treatment would be able to reduce the volume, degrading the resins and increasing the load capacity of this material. This paper is about a method of degradation of ion spent resins from the nuclear research reactor of Nuclear and Energy Research Institute (IPEN/CNEN-SP), Brazil, using the Fenton's reagent. The resin evaluated was a mixture of cationic and anionic resins. The reactions were conducted by varying the concentration of the catalyst (25 to 80 mM), with and without external heat. The time of reaction was two hours. The concentration of 50 mM of catalyst was the most effective in degrading approximately 99%. The resin degradation was confirmed by the presence of CaCO3 as a white precipitate resulting from the reaction between the Ca(OH)2 and the CO2 from the resin degradation. It was possible to degrade the resins without external heating. The calcium carbonates showed no correlation with the residual resin mass. (author)

  10. Self-catalytic degradation of ortho-chlorophenol with Fenton's reagent studied by chemiluminescence

    Institute of Scientific and Technical Information of China (English)

    Zhen Lin; HuiChen; Yun Zhou; Nobuaki Ogawa; Jin-Ming Lin

    2012-01-01

    The degradation of ortho-chlorophenol using Fenton's reagent was studied by chemiluminescence(CL).Without a special CL reagent,a weak CL emission from the mixture of ferrous ion and hydrogen peroxide was observed at room temperature.The CL intensity was increased by the addition of ortho-chlorophenol into the mixed solution.When the temperature was raised to 65℃,the CL intensity was enhanced strongly.The CL mechanisms for the system H2O2-Fe2+ with and without ortho-chlorophenol were studied by examining the CL spectrum,gas chromatography-mass spectrometry and electron spin resonance spectrum.The effects of various free radical scavengers,surfactants and fluorescence compounds on the CL intensity were also investigated.A self-catalytic oxidation mechanism was proposed.The results showed that singlet oxygen was the main emitter for the system H2O2-Fe2+.The strong CL from the system H2O2-Fe2+-ortho-chlorophenol was due to singlet oxygen and electronically excited quinone.The benzenediol-like intermediate product formed during the phenol oxidation process greatly promoted the Fenton's reaction and led to higher CL intensity.Chemiluninescence is a novel approach for the investigation of the oxidation of some organic pollutants by Fenton's reagent.

  11. Fenton's treatment as an effective treatment for elderberry effluents: economical evaluation.

    Science.gov (United States)

    Amaral-Silva, Nuno; Martins, Rui C; Castro-Silva, Sérgio; Quinta-Ferreira, Rosa M

    2016-05-01

    The utilization of Fenton's oxidation for the depuration of elderberry juice wastewater was studied. The aim was to select the adequate cost-effective operating conditions suitable to lead to an effluent within the legal thresholds to be discharged into the natural water courses. The treatment efficacy was assessed by chemical oxygen demand (COD), colour, phenolic content and total solids removal besides its ability to improve biodegradability (biochemical oxygen demand (BOD5)/COD). Moreover, the costs of the applied reactants were also considered. Fenton's reaction was able to abate at least 70% of COD (corresponding to a final value below 150 mg O2 L(-1)). Besides, total phenolic content degradation was always achieved. Within these conditions, the resulting effluent is able to be directly discharged into the natural hydric channels. Fenton oxidation could be successfully applied as a single treatment method with a reactant cost of 4.38 € m(-3) ([Fe(2+)] = 20 mmol L(-1), [H2O2] = 100 mmol L(-1), pH = 3 and 4 h of oxidation procedure). PMID:26507382

  12. Paracetamol degradation intermediates and toxicity during photo-Fenton treatment using different iron species.

    Science.gov (United States)

    Trovó, Alam G; Pupo Nogueira, Raquel F; Agüera, Ana; Fernandez-Alba, Amadeo R; Malato, Sixto

    2012-10-15

    The photo-Fenton degradation of paracetamol (PCT) was evaluated using FeSO(4) and the iron complex potassium ferrioxalate (FeOx) as iron source under simulated solar light. The efficiency of the degradation process was evaluated considering the decay of PCT and total organic carbon concentration and the generation of carboxylic acids, ammonium and nitrate, expressed as total nitrogen. The results showed that the degradation was favored in the presence of FeSO(4) in relation to FeOx. The higher concentration of hydroxylated intermediates generated in the presence of FeSO(4) in relation to FeOx probably enhanced the reduction of Fe(III) to Fe(II) improving the degradation efficiency. The degradation products were determined using liquid chromatography electrospray time-of-flight mass spectrometry. Although at different concentrations, the same intermediates were generated using either FeSO(4) or FeOx, which were mainly products of hydroxylation reactions and acetamide. The toxicity of the sample for Vibrio fischeri and Daphnia magna decreased from 100% to less than 40% during photo-Fenton treatment in the presence of both iron species, except for D. magna in the presence of FeOx due to the toxicity of oxalate to this organism. The considerable decrease of the sample toxicity during photo-Fenton treatment using FeSO(4) indicates a safe application of the process for the removal of this pharmaceutical. PMID:22863025

  13. Photochemically enhanced degradation of phenol using heterogeneous Fenton-type catalysts

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The degradation of phenol was carried out using heterogeneous Fenton-type catalysts in the presence of H2O2 and UV. Catalysts were prepared by exchanging and immobilizing Fe2+ in zeolite 13X, silica gel or Al2O3. The concentration of phenol solution was 100 mg/L. The amount of H2O2 added was the stoichiometric amount of H2O2 required for the total oxidation of phenol. Under the irradiation of medium pressure light (300W) phenol was mineralized within 1h in the presence of Fe2+/zeolite 13X. The COD removal rate was enhanced in the presence of Fe2+/zeolite13X compared to that of Fe2+/silica gel or Fe2+/Al2O3. Analogous homogenous photo-Fenton reaction with equivalent Fe2+ was also carried out to evaluate the catalysis efficiency of Fe2+/zeolite 13X. Results showed that the COD removal rate was near to that of homogeneous Fenton, while heterogeneous Fe2+/zeolite 13X catalyst could be recycled.

  14. Fenton process for degradation of selected chlorinated aliphatic hydrocarbons exemplified by trichloroethylene, 1,1-dichloroethylene and chloroform

    Institute of Scientific and Technical Information of China (English)

    Zhimin QIANG; Weiwei BEN; ChinPao HUANG

    2008-01-01

    The degradation of selected chlorinated ali-phatic hydrocarbons (CAHs) exemplified by trichloroethy-lene (TCE), 1,1-dichloroethylene (DCE), and chloroform (CF) was investigated with Fenton oxidation process. The results indicate that the degradation rate was primarily affected by the chemical structures of organic contami-nants. Hydroxyl radicals (·OH) preferred to attack the organic contaminants with an electron-rich structure such as chlorinated alkenes (i.e., TCE and DCE). The dosing mode of Fenton's reagent, particularly of Fe2+, significantly affected the degradation efficiency of studied organic compound. A new "time-squared" kinetic model, C = Coexp(-kobst2), was developed to express the degrada-tion kinetics of selected CAHs. This model was applicable to TCE and DCE, but inapplicable to CF due to their varied reaction rate constants towards ·OH. Chloride release was monitored to examine the degree of dechlorina- tion during the oxidation of selected CAHs. TCE was more easily dechlorinated than DCE and CF. Dichloroacetic acid (DCAA) was identified as the major reaction intermediate in the oxidation of TCE, which could be completely removed as the reaction proceeded. No reaction intermedi- ates or byproducts were identified in the oxidation of DCE and CF. Based on the identified intermediate, the reaction mechanism of TCE with Fenton's reagent was proposed.

  15. Fenton-like oxidation of 2,4-DCP in aqueous solution using iron-based nanoparticles as the heterogeneous catalyst.

    Science.gov (United States)

    Li, Renchao; Gao, Ying; Jin, Xiaoying; Chen, Zuliang; Megharaj, Mallavarapu; Naidu, Ravendra

    2015-01-15

    In this report, various iron-based nanoparticles (nZVI, n-Ni/Fe, n-Pd/Fe) were used for both heterogeneous Fenton oxidation of 2,4-dichlorophenol (2,4-DCP) and reductive dechlorination of 2,4-DCP in order to understand their roles in the Fenton oxidation and the reductive degradation of 2,4-DCP. The dechlorination efficiency of 2,4-DCP using nZVI, n-Ni/Fe, n-Fe/Pd and Fe(2)(+) was 6.48%, 6.80%, 15.95%, 5.02%, while Fenton oxidation efficiency of 2,4-DCP was 57.87%, 34.23%, 27.94%, 19.61% after 180 min, respectively. The new findings included a higher dechlorination using n-Fe/Pd due to Pd effective catalysis and the effective heterogeneous Fenton oxidation using nZVI depending on reductive dechlorination and heterogeneous Fenton oxidation occurs simultaneously. However, nZVI as the potential catalyst for heterogeneous Fenton was observed, and SEM, EDS and XRD demonstrate that change on the nZVI surface occurred due to the Fe(2+) leaching, and Total Organic Carbon (TOC) (30.71%) shows that 2,4-DCP was degraded. Furthermore, the experiment indicates that the pH values and concentration of 2,4-DCP significantly impacted on the heterogeneous Fenton oxidation of 2,4-DCP and the data fits well with the pseudo first-order kinetic model, which was a diffusion-controlled reaction. Finally, a possible mechanism for degradation of 2,4-DCP was proposed. PMID:25454429

  16. The decontamination of bleaching effluent by pilot-scale solar Fenton process.

    Science.gov (United States)

    Wang, Zhaojiang; Chen, Kefu; Li, Jun; Mo, Lihuan

    2011-01-01

    A solar Fenton process was applied as post-treatment to selectively eliminate organic pollutants and toxicants in bleaching effluents of kraft pulp mills. Experiments were conducted to study the effect of system parameters (pH, initial concentration of H2O2, molar ratio of Fe2+/H2O2 and solar-UV irradiance) on the removals of chemical oxygen demand and colour. The results showed 92.8% of COD and 99.6% of colour were removed at pH 3.5, H2O2 30 mM/ L, Fe2+/H2O2 1:100, solar-UV irradiance 11070 mW/m2, reaction time 120 min. The first-order kinetic model was used to study the dependence of the reaction rate on solar-UV irradiance: a linear relationship was shown to exist between reaction rate constants and solar-UV irradiance. The results of gas chromatography mass spectrometry analysis showed that the toxicity of the bleaching effluents was mainly derived from the presence of mononuclear aromatics, polycyclic aromatic hydrocarbons and organochlorides, which were all degraded into harmless organic acids under the attack of hydroxyl radicals generated from the solar Fenton reaction. PMID:21879547

  17. Evaluation of Electro-Fenton Process Performance for COD and Reactive Blue 19 Removal from Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Mohammad Malakootian

    2013-02-01

    Full Text Available Background and Objectives: Synthetic dyes represent one of the largest groups of pollutants in wastewater of dying industries. Discharging these wastewaters into receiving streams not only affects the aesthetic but also reduces photosynthetic activity. Electrochemical advanced oxidation processes such as Electro-Fenton process are low operational and have high mineralization degree of pollutants. In this study, we investigated affective factors in this process to determine the optimum conditions for dye and COD removal from aqueous solutions containing Reactive Blue 19 dye.Materials and Methods: Synthetic samples containing Reactive Blue 19 dye were prepared by dissolving dye powder in double distilled water. and the the solution prepared was transferred into pilot electrochemical cell having two anode and cathode electrode made of iron and carbon. Electro-Fenton process was began by adding of Fe2+ ions and establishing electrical potential difference. After testing and at specified time intervals, each sample was collected from the pilot cell, and process performance was evaluated through measuring dye concentration and COD. Results: Based on the results obtained, optimum conditions of Electro-Fenton process for dye and COD removal was determined. Accordingly, potential difference of 20 volt for dye concentration up to 100 mg/L and potential difference of 30 volt for dye concentration of more than 200 mg/L, reaction time 60 minutes, 0.5 mg/L of Fe2+ concentration and suitable pH for the maximum dye removal efficiency equaled 4 respectively. Under such conditions, the dye and COD removal was 100 and 95% respectively.Conclusion: Based on the results obtained, it was revealed that Electro-Fenton process has significant ability in not only dye removal but also in COD removal. Accordingly, it was found that the effective parameters in Electro-Fenton process for removal Reactive Blue19 dye are electric potential difference, concentration of iron ions

  18. Study on Treatability of Real Textile Wastewater by Electrochemically Generated  Fenton Reagent using Graphite Felt Cathode

    Directory of Open Access Journals (Sweden)

    Akbar Eslami

    2012-10-01

    Full Text Available Background and Objectives: Electro-Fenton process has been widely applied for dye removal from aqueous solution lately. Fenton's reagent is formed in the electrolysis medium through the simultaneous electrochemical reduction of O2 and Fe3+ to H2O2 and Fe2+ respectively on the cathode surface. In this paper, COD reduction potential and decolorization of real textile wastewater were evaluated by electrochemically generated Fenton reagent process. This wastewater mainly contains non-biodegradable acidic dyes, which are highly resistant against conventional oxidizing agents.Materials and Methods: Electro-Fenton process was carried out in an open and undivided cell in order to evaluate the removal of color and COD from real textile wastewater using graphite felt (cathode and Pt plate (anode at room temperature. The effects of current density, flow rate of air, electrolysis time, initial pH, and ferrous ion concentration were investigated for real textile wastewater.Results: The results showed that the optimal experimental conditions obtained in electrochemical studies were as follows: current density=4.8 mA cm-2, pH=3, flow rate of air=1.5L/min, Fe2+=3mM and reaction time=160 min. Under these conditions, COD removal and decolorization achieved were 63% and 77.2% respectively. Conclusion: According to the results achieved, electro-Fenton process can be used as a pretreatment for degradation of colored wastewater and refractory pollutants. Moreover, this feasible technology improves biodegradability of the textile wastewater.

  19. Model-based opportunities for the optimization of the dosage of hydrogen peroxide in the photo Fenton process

    OpenAIRE

    Campanyà Gratacós, Gerard; Graells Sobré, Moisès; Lie, Bernt

    2014-01-01

    Advanced Oxidation Processes (AOP) have been proposed as alternative water treatments coping with recalcitrant organic pollutants [1]. AOPs are based on in-situ generation of highly oxidant hydroxyl radicals. Particularly, in the photo-Fenton process they are produced from ferrous salts (Fe) and hydrogen peroxide (HP). However, this process has been acknowledged to suffer inefficient reactions scavenging HP; which has motivated a large amount of research aimed to determine efficient ratios fo...

  20. Treatment of Effluent from a Factory of Paints Using Solar Photo-Fenton Process

    OpenAIRE

    Alam Gustavo Trovó; Oswaldo Gomes; Antonio Eduardo da Hora Machado

    2013-01-01

    We evaluated the use of Fenton reactions induced by solar radiation in the treatment of effluent from a factory of paints for buildings, after prior removal of the suspended solids. The increase of H2O2 concentration from 100 to 2500 mg L−1 for a [Fe2+] = 105 mg L−1 contributed to the reduction of DOC, COD, and toxicity. Our best results were achieved using 1600 mg L−1 H2O2, with 90% of DOC and COD removal and a complete removal of the toxicity with respect to Artemia salina. Additionally, th...

  1. Heterogeneous photo-Fenton oxidation with natural clays for phenol and tyrosol remediation

    Directory of Open Access Journals (Sweden)

    Djeffal L.

    2013-09-01

    Full Text Available Due to their excellent properties, clays have been widely used in several applications, particularly in catalysis. In this paper, three clays were used as heterogeneous photo-Fenton catalysts for phenol and tyrosol oxidations. Particular attention was given to the effect of the main operating conditions on the process performance. A total conversion was obtained for both organic pollutants with studied catalysts in 20 minutes reaction. For phenol, a total organic carbon (TOC conversion of 93% was obtained using sieved and calcined smectite clay. The TOC conversion was 60% for tyrosol with the same catalyst. Clays were characterized by chemical analysis, BET, XRD, TPR and SEM.

  2. Treatment of mature landfill leachate by chemical precipitation and Fenton advanced oxidation process

    OpenAIRE

    Nemat Alah Jaafarzadeh Haghighi Fard; Sahand Jorfi; Mehdi Ahmadi; Samaneh Mirali; Raheleh Kujlu

    2016-01-01

    Background: Mature landfill leachate is a complicated mixture which is resistant to biological treatment processes. The treatment of mature landfill leachate by struvite precipitation and Fenton oxidation was the main objective of the current research. Methods: Struvite with the phosphate/ammonia/magnesium molar ratio of 1/1/1.05 was considered during all experiments. Five initial pHs of 3, 4, 5, 6, and 7, four different H2O2/Fe mass ratios of 50, 100, 200, and 400, and reaction times of ...

  3. FePt nanoparticles as heterogeneous Fenton-like catalysts for hydrogen peroxide decomposition and the decolorization of methylene blue

    International Nuclear Information System (INIS)

    In this report, we show that superparamagnetic FePt nanoparticles are highly efficient heterogeneous Fenton-like oxidation catalysts and compare their performance to Fe3O4 nanoparticles using methylene blue dye as the target organic. X-ray diffraction and transmission electron microscopy were used to characterize the structure of the nanoparticles, a superconducting quantum interference device confirmed the magnetic properties, X-ray photoelectron spectroscopy characterized the chemical state of Fe in the nanoparticles, and ultraviolet–visible spectroscopy was used to monitor the heterogeneous Fenton-like reaction. The pseudo-first-order reaction rate constant for 5 ppm FePt nanoparticles was approximately 100 times faster than for 5 ppm Fe3O4 nanoparticles under otherwise identical conditions. Furthermore, a concentration of 2,500 ppm Fe3O4 was required to achieve the same reaction extent as 5 ppm FePt. Thus, FePt nanoparticles are more efficient heterogeneous Fenton-like catalyst for H2O2 decomposition and methylene blue decolorization than Fe3O4. Further, as both types of nanoparticles are superparamagnetic, they can easily be reclaimed and reused.

  4. Fenton coupled with nanofiltration for elimination of Bisphenol A

    OpenAIRE

    I. Escalona; Fortuny Sanromá, Agustín; Stueber, Frank; Bengoa, Christophe José; Fabregat Llangotera, Azael; Font Capafons, Josep

    2014-01-01

    Bisphenol A (BPA) is a typical Endocrine Disrupting Chemical (EDC), which is potentially harmful during wastewater reclamation. In this study, its degradation during Fenton's process under different operational conditions was investigated in combination with subsequent nanofiltration of low concentration remnant BPA and compounds derived from oxidation. The results indicate that BPA could be degraded efficiently in aqueous phase by Fenton, even at very low hydrogen peroxide doses. The treatme...

  5. Degradation of ion spent resin using the Fenton's reagent

    International Nuclear Information System (INIS)

    The most common method for spent radioactive ion exchange resin treatment is its immobilization in cement, which reduces the radionuclides release into the environment. Although this method is efficient, it increases considerably the final volume of the waste due to the low incorporation capacity. The objective of this work was to develop a degradation method of spent resins arising from the nuclear research reactor located at the Nuclear and Energy Research Institute (IPEN-CNEN/SP), using an Advanced Oxidation Process (AOP) with Fenton's reagents. This method would allow a higher incorporation in cement. Three different resins were evaluated: cationic, anionic and a mixture of both resins. The reactions were conducted varying the catalyst concentration (25, 50, 100 and 150 mM), the volume of hydrogen peroxide (320 to 460 mL), and three different temperatures, 50, 60 and 70 deg C. Degradation of about 98% was achieved using a 50 mM catalyst solution and 330 mL of hydrogen peroxide solution. The most efficient temperature was 60 deg C. (author)

  6. Treatment of pharmaceutical wastewater containing recalcitrant compounds in a Fenton-coagulation process

    Institute of Scientific and Technical Information of China (English)

    XING Mei-yan; DENG Can; Bukuru Godefroid; YANG Jian

    2006-01-01

    The advanced treatment using integrated Fenton's reaction and coagulation process was investigated in this study. Before the advancement, the pharmaceutical wastewater containing lincomycin hydrochloride was pretreated by UASB (upflow anaerobic sludge bed) and a SBR (sequencing batch reactor) process. The residual recalcitrant compounds, measured by gas chromatographymass spectrometry (GC-MS), mainly consisted of alcohols, phenols, and nitrogenous and sulfur compounds. The experimental results indicated that when the Fenton' s reaction was conducted at pH=3.0, H2O2/CODCr = 0.27, H2O2/Fe2+ = 3:1 and 30 min of reaction time,and the coagulation process operated at a sulfate aluminum concentration of 800 mg/L and pH value of 5.0, the color and COD in the wastewater decreased by 94% and 73%, respectively; with a finale COD concentration of 267 mg/L and color level of 40 units,meeting the secondary standard of GB8978-1996 for industrial wastewater.

  7. Microbial fuel cells using natural pyrrhotite as the cathodic heterogeneous Fenton catalyst towards the degradation of biorefractory organics in landfill leachate

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yan; Lu, Anhuai; Ding, Hongrui; Wang, Xin; Wang, Changqiu; Zeng, Cuiping; Yan, Yunhua [The Key Laboratory of Orogenic Belts and Crustal Evolution, School of Earth and Space Sciences, Peking University, Beijing 100871 (China)

    2010-07-15

    An investigation aimed at checking the integration of cathodic pyrrhotite Fenton's reaction with anodic microbial respiration for the enhancement of MFC performance and treatment of a real landfill leachate was carried out. The MFC equipped with a pyrrhotite-coated graphite-cathode generated the maximum power density of 4.2 W/m{sup 3} that was 133% higher than graphite-cathode. Concomitantly, electrochemical impedance spectroscopy (EIS) showed that the polarization resistance of pyrrhotite-cathode (92 {omega}) was much lower than the graphite-cathode (1057 {omega}), indicating that the cathodic overpotential was significantly lowered, probably due to the occurrence of pyrrhotite Fenton's reaction. The in situ generation of Fenton's reagents (Fe{sup 2+} and H{sub 2}O{sub 2}) at the pyrrhotite-cathode was demonstrated by the cyclic voltammetry measurement. Besides, reactive oxygen species produced from the pyrrhotite Fenton's reaction were detected and demonstrated to be vital to the enhancement of MFC power output. Further, the effectiveness of this system was examined by treating an old-aged landfill leachate. 77% of color and 78% of COD were removed from the original leachate, indicating that the pyrrhotite not only acted as a cost-effective cathodic catalyst for MFCs in power generation, but also extended the practical merits of traditional MFCs towards advanced oxidation of biorefractory pollutants. (author)

  8. A study of catalytic behaviour of aromatic additives on the photo-Fenton degradation of phenol red

    Indian Academy of Sciences (India)

    Abhilasha Jain; Savitri Lodha; P B Punjabi; V K Sharma; Suresh C Ameta

    2009-11-01

    The present study describes the photochemical degradation of phenol-red using photo-Fenton reaction. The progress of the reaction has been monitored spectrophotometrically. The effect of various organic additives e.g. hydroquinone, resorcinol and catechol on the rate of photodegradation has been observed. The effect of variation of various parameters such as pH, concentration of dye, Fe3+ ion and additives, amount of H2O2, and light intensity on the rate of photodegradation was also observed. A tentative mechanism of the reaction has been proposed.

  9. Pyrene Removal from Contaminated Soils by Modified Fenton Oxidation Using Iron Nano Particles

    Directory of Open Access Journals (Sweden)

    Sahand Jorfi

    2013-07-01

    Full Text Available Background:The problems related to conventional Fenton oxidation, including low pH required and production of considerable amounts of sludge have led researchers to investigate chelating agents which might improve the operating range of pH and the use of nano iron particle to reduce the excess sludge. The pyrene removal from contaminated soils by modified Fenton oxidation at neutral pH was defined as the main objective of the current study.Methods:Varying concentrations of H2O2 (0-500 mM and iron nano oxide (0-60 mM, reaction times of 0.5-24 hours and variety of chelating agents including sodium pyrophosphate, sodium citrate, ethylene diamine tetraacetic, fulvic and humic acid were all investigated at pyrene concentration levels of 100 – 500 mg/kg.Results:By applying the following conditions (H2O2 concentration of 300 mM, iron nano oxide of 30 mM, sodium pyrophosphate as chelating agent, pH 3 and reaction time of 6 hours the pyrene removal efficiency at an initial concentration of 100 mg/kg was found to be 99%. As a result, the pyrene concentration was reduced from 100 to 93 mg/kg once the above optimum conditions are met.Conclusions:In this research, the modified Fenton oxidation using iron nano oxide at optimum conditions is introduced as an efficient alternative method in lab scale for chemical remediation or pre-treatment of soils contaminated by pyrene at neutral pH.

  10. The Study of Fenton Performance in Removal of  Cyanide from Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Somayeh Golbaz

    2013-02-01

    Full Text Available Background and Objectives: Cyanide is a toxic pollutant existing in the various industrial effluents such as iron and steel, coal mining, non-ferrous metals manufacturing and metal plating. Its presence in water resources and wastewater, as serious hazardous substances leads to undesirable effects on both the environment and human. Thus, its concentration control is essential for human health. The main goal of this study was to evaluate Fenton process efficiency in cyanide removal from aqueous solution.Materials and Methods: This is an experimental study Conducted at Lab scale in a batch system. We investigated effect of different variables including; pH, mole ratio of Fe2+/ H2O2, contact time, and initial concentration of cyanide. Data were analyzed using Excel software.Results: We found that cyanide with initial concentrations of 0.4 mM/L was reduced by 92 %. This removal result was related to oxidizing agent of hydroxyl radicals under optimum conditions including; pH = 4, molar ratio Fe2+/ H2O2= 0.046 (Fe2+=0.27 mM/L after 6o min reaction time. An increase in reaction time was not improved cyanide removal efficiency. Moreover, the Fenton process efficiency in cyanide removal decreased from 92 to 60 %, by increasing the initial cyanide concentration from 0.4 to 0.6 mM/L.Conclusion: It can be concluded that Fenton oxidation Process can be considered as a suitable alternative for cyanide removal to achieve environmental standards.

  11. Degradation of Phenol with Fenton-like Treatment by Using Heterogeneous Catalyst (Modified Iron Oxide) and Hydrogen Peroxide

    International Nuclear Information System (INIS)

    Goethite, hematite, magnetite and synthesized iron oxide are used as catalysts for Fenton-type oxidation of phenol. The synthesized iron oxides were characterized by X-ray diffraction (XRD), BET, X-ray photoelectron spectroscopy (XPS), and electron paramagnetic resonance (EPR). The catalytic activity of these materials is classified according to the observed rate of phenol oxidation. The effectiveness of the catalysts followed the sequence: ferrous ion > synthesized iron oxide >> magnetite hematite > goethite. According to these results, the most effective iron oxide catalyst had the structure similar to natural hematite. The surface oxidation state of the catalyst was between magnetite and hematite (+2.5 ∼ +3.0). Phenol degraded completely in 40 min at neutral pH (pH = 7). Soluble ferric and ferrous ions were not detected in the filtrate from Fenton reaction solution by AAS. The formation of hydroxyl radicals was confirmed by EPR

  12. Optimization of conventional Fenton and ultraviolet-assisted oxidation processes for the treatment of reverse osmosis retentate from a paper mill.

    Science.gov (United States)

    Hermosilla, Daphne; Merayo, Noemí; Ordóñez, Ruth; Blanco, Angeles

    2012-06-01

    According to current environmental legislation concerned with water scarcity, paper industry is being forced to adopt a zero liquid effluent policy. In consequence, reverse osmosis (RO) systems are being assessed as the final step of effluent treatment trains aiming to recover final wastewater and reuse it as process water. One of the most important drawbacks of these treatments is the production of a retentated stream, which is usually highly loaded with biorecalcitrant organic matter and inorganics; and this effluent must meet current legislation stringent constraints before being ultimately disposed. The treatment of biorefractory RO retentate from a paper mill by several promising advanced oxidation processes (AOPs) - conventional Fenton, photo-Fenton and photocatalysis - was optimized considering the effect and interaction of reaction parameters; particularly using response surface methodology (RSM) when appropriate (Fenton processes). The economical cost of these treatments was also comparatively assessed. Photo-Fenton process was able to totally remove the COD of the retentate, and resulted even operatively cheaper at high COD removal levels than conventional Fenton, which achieved an 80% reduction of the COD at best. In addition, although these optimal results were produced at pH=2.8, it was also tested that Fenton processes are able to achieve good COD reduction efficiencies (>60%) without adjusting the initial pH value, provided the natural pH of this wastewater was close to neutral. Finally, although TiO(2)-photocatalysis showed the least efficient and most expensive figures, it improved the biodegradability of the retentate, so its combination with a final biological step almost achieved the total removal of the COD. PMID:22244652

  13. Combined photo-Fenton-SBR process for antibiotic wastewater treatment

    International Nuclear Information System (INIS)

    Highlights: · The work focused on hazardous wastewater (antibiotic wastewater) treatment. · Complete degradation of the antibiotics achieved by the treatment process. · The SBR performance was found to be very sensitive to BOD5/COD ratio below 0.40. · Combined photo-Fenton-SBR process is a feasible treatment process for the antibiotic wastewater. - Abstract: The study examined combined photo-Fenton-SBR treatment of an antibiotic wastewater containing amoxicillin and cloxacillin. Optimum H2O2/COD and H2O2/Fe2+ molar ratio of the photo-Fenton pretreatment were observed to be 2.5 and 20, respectively. Complete degradation of the antibiotics occurred in one min. The sequencing batch reactor (SBR) was operated at different hydraulic retention times (HRTs) with the wastewater treated under different photo-Fenton operating conditions (H2O2/COD and H2O2/Fe2+ molar ratio). The SBR performance was found to be very sensitive to BOD5/COD ratio of the photo-Fenton treated wastewater. Statistical analysis of the results indicated that it was possible to reduce the Fe2+ dose and increase the irradiation time of the photo-Fenton pretreatment. The best operating conditions of the combined photo-Fenton-SBR treatment were observed to be H2O2/COD molar ratio 2, H2O2/Fe2+ molar ratio 150, irradiation time 90 min and HRT of 12 h. Under the best operating conditions, 89% removal of sCOD with complete nitrification was achieved and the SBR effluent met the discharge standards.

  14. Combined photo-Fenton-SBR process for antibiotic wastewater treatment

    Energy Technology Data Exchange (ETDEWEB)

    Elmolla, Emad S., E-mail: em_civil@yahoo.com [Department of Civil Engineering, Faculty of Engineering, Al-Azhar University, Cairo (Egypt); Chaudhuri, Malay [Department of Civil Engineering, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750 Tronoh, Perak (Malaysia)

    2011-09-15

    Highlights: {center_dot} The work focused on hazardous wastewater (antibiotic wastewater) treatment. {center_dot} Complete degradation of the antibiotics achieved by the treatment process. {center_dot} The SBR performance was found to be very sensitive to BOD{sub 5}/COD ratio below 0.40. {center_dot} Combined photo-Fenton-SBR process is a feasible treatment process for the antibiotic wastewater. - Abstract: The study examined combined photo-Fenton-SBR treatment of an antibiotic wastewater containing amoxicillin and cloxacillin. Optimum H{sub 2}O{sub 2}/COD and H{sub 2}O{sub 2}/Fe{sup 2+} molar ratio of the photo-Fenton pretreatment were observed to be 2.5 and 20, respectively. Complete degradation of the antibiotics occurred in one min. The sequencing batch reactor (SBR) was operated at different hydraulic retention times (HRTs) with the wastewater treated under different photo-Fenton operating conditions (H{sub 2}O{sub 2}/COD and H{sub 2}O{sub 2}/Fe{sup 2+} molar ratio). The SBR performance was found to be very sensitive to BOD{sub 5}/COD ratio of the photo-Fenton treated wastewater. Statistical analysis of the results indicated that it was possible to reduce the Fe{sup 2+} dose and increase the irradiation time of the photo-Fenton pretreatment. The best operating conditions of the combined photo-Fenton-SBR treatment were observed to be H{sub 2}O{sub 2}/COD molar ratio 2, H{sub 2}O{sub 2}/Fe{sup 2+} molar ratio 150, irradiation time 90 min and HRT of 12 h. Under the best operating conditions, 89% removal of sCOD with complete nitrification was achieved and the SBR effluent met the discharge standards.

  15. Niobium substituted magnetite as a strong heterogeneous Fenton catalyst for wastewater treatment

    Energy Technology Data Exchange (ETDEWEB)

    Rahim Pouran, Shima, E-mail: rahimpooran@yahoo.com [Chemical Engineering Department, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia); Abdul Aziz, A.R., E-mail: azizraman@um.edu.my [Chemical Engineering Department, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia); Wan Daud, Wan Mohd Ashri, E-mail: ashri@um.edu.my [Chemical Engineering Department, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia); Embong, Zaidi, E-mail: zembong@gmail.com [Faculty of Science, Technology and Human Development, University Tun Hussein Onn Malaysia, 86400 Johor (Malaysia)

    2015-10-01

    Highlights: • A series of Nb substituted magnetite samples were prepared and characterized. • Samples had inverse spinel structure, good magnetic property, and durability. • Increased surface area resulted in higher adsorption capacity of the samples. • Nb incorporation enhanced degradation of methylene blue through Fenton reaction. • The activity of the catalysts increased by increment in Nb content of the samples. - Abstract: In this study, a series of Nb substituted magnetites; Fe{sub 3−x}Nb{sub x}O{sub 4} (x = 0.0, 0.022, 0.049, 0.099, and 0.19) were prepared and characterized by XRD, BET surface area, TEM, VSM, XPS, and chemical experiments. The magnetite inverse spinel structure and magnetic property were maintained in all the synthetized samples. A significant decrease in crystal size (≈two times) and increase in specific surface area (≈three times) were observed with increased Nb content, resulting in higher adsorption capacity of the samples. In addition, the reactivity of the synthetized samples was examined through degradation of methylene blue solution using Fenton-like reaction. It was found that the incorporation of niobium significantly improved the degradation of methylene blue of which total MB removal was achieved within 180 min at higher molar ratios of Nb (x = 0.19). This could be attributed to the generated oxygen vacancies on the surface of catalysts, the contribution of the introduced Nb cations in Fenton oxidation cycle for regeneration of Fe{sup 2+} cations, and increase in adsorption capacity of the samples due to larger surface area. The MB degradation through Fe{sub 2.79}Nb{sub 0.19}O{sub 4}/H{sub 2}O{sub 2} system was well described by the pseudo-first-order equation in kinetics. All samples showed good stability under the studied pH conditions. The amount of niobium leached was not detectable in neutral and basic solutions and the samples could be reused in oxidation process for several times without a significant

  16. Niobium substituted magnetite as a strong heterogeneous Fenton catalyst for wastewater treatment

    International Nuclear Information System (INIS)

    Highlights: • A series of Nb substituted magnetite samples were prepared and characterized. • Samples had inverse spinel structure, good magnetic property, and durability. • Increased surface area resulted in higher adsorption capacity of the samples. • Nb incorporation enhanced degradation of methylene blue through Fenton reaction. • The activity of the catalysts increased by increment in Nb content of the samples. - Abstract: In this study, a series of Nb substituted magnetites; Fe3−xNbxO4 (x = 0.0, 0.022, 0.049, 0.099, and 0.19) were prepared and characterized by XRD, BET surface area, TEM, VSM, XPS, and chemical experiments. The magnetite inverse spinel structure and magnetic property were maintained in all the synthetized samples. A significant decrease in crystal size (≈two times) and increase in specific surface area (≈three times) were observed with increased Nb content, resulting in higher adsorption capacity of the samples. In addition, the reactivity of the synthetized samples was examined through degradation of methylene blue solution using Fenton-like reaction. It was found that the incorporation of niobium significantly improved the degradation of methylene blue of which total MB removal was achieved within 180 min at higher molar ratios of Nb (x = 0.19). This could be attributed to the generated oxygen vacancies on the surface of catalysts, the contribution of the introduced Nb cations in Fenton oxidation cycle for regeneration of Fe2+ cations, and increase in adsorption capacity of the samples due to larger surface area. The MB degradation through Fe2.79Nb0.19O4/H2O2 system was well described by the pseudo-first-order equation in kinetics. All samples showed good stability under the studied pH conditions. The amount of niobium leached was not detectable in neutral and basic solutions and the samples could be reused in oxidation process for several times without a significant decrease in their catalytic efficiency. The results proved

  17. Efficient degradation of Acid Orange 7 in aqueous solution by iron ore tailing Fenton-like process.

    Science.gov (United States)

    Zheng, Jianming; Gao, Zhanqi; He, Huan; Yang, Shaogui; Sun, Cheng

    2016-05-01

    An effective method based on iron ore tailing Fenton-like process was studied for removing an azo dye, Acid Orange 7 (AO7) in aqueous solution. Five tailings were characterized by X-ray fluorescence spectroscope (XFS), Brunner-Emmet-Teller (BET) measurement, and Scanning Electron Microscope (SEM). The result of XFS showed that Fe, Si and Ca were the most abundant elements and some toxic heavy metals were also present in the studied tailings. The result of BET analysis indicated that the studied tailings had very low surface areas (0.64-5.68 m(2) g(-1)). The degradation efficiencies of AO7 were positively correlated with the content of iron oxide and cupric oxide, and not related with the BET surface area of the tailings. The co-existing metal elements, particularly Cu, might accelerate the heterogeneous Fenton-like reaction. The effects of other parameters on heterogeneous Fenton-like degradation of AO7 by a converter slag iron tailing (tailing E) which contains highest iron oxide were also investigated. The tailing could be reused 10 times without significant decrease of the catalytic capacity. Very low amount of iron species and almost undetectable toxic elements were leached in the catalytic degradation of AO7 by the tailing E. The reaction products were identified by gas chromatography-mass spectrometry and a possible pathway of AO7 degradation was proposed. This study not only provides an effective method for removing azo dyes in polluted water by employing waste tailings as Fenton-like catalysts, but also uses waste tailings as the secondary resource. PMID:26891355

  18. Combined treatment of retting flax wastewater using Fenton oxidation and granular activated carbon

    Directory of Open Access Journals (Sweden)

    Sohair I. Abou-Elela

    2016-07-01

    Full Text Available The process of retting flax produces a huge amount of wastewater which is characterized with bad unpleasant smell and high concentration of organic materials. Treatment of such waste had always been difficult because of the presence of refractory organic pollutants such as lignin. In this study, treatment of retting wastewater was carried out using combined system of Fenton oxidation process followed by adsorption on granular activated carbon (GAC. The effects of operating condition on Fenton oxidation process such as hydrogen peroxide and iron concentration were investigated. In addition, kinetic study of the adsorption process was elaborated. The obtained results indicated that degradation of organic matters follows a pseudo-first order reaction with regression coefficient of 0.98. The kinetic model suggested that the rate of reaction was highly affected by the concentration of hydrogen peroxide. Moreover, the results indicated that the treatment module was very efficient in removing the organic and inorganic pollutants. The average percentage removal of chemical oxygen demand (COD, total suspended solid (TSS, oil, and grease was 98.60%, 86.60%, and 94.22% with residual values of 44, 20, and 5 mg/L, respectively. The treated effluent was complying with the National Regulatory Standards for wastewater discharge into surface water or reuse in the retting process.

  19. Degradation of Amaranth azo dye in water by heterogeneous photo-Fenton process using FeWO4 catalyst prepared by microwave irradiation.

    Science.gov (United States)

    da Cruz Severo, Eric; Anchieta, Chayene Gonçalves; Foletto, Vitória Segabinazzi; Kuhn, Raquel Cristine; Collazzo, Gabriela Carvalho; Mazutti, Marcio Antonio; Foletto, Edson Luiz

    2016-01-01

    FeWO4 particles were synthesized by a simple, rapid and facile microwave technique and their catalytic properties in heterogeneous photo-Fenton reaction were evaluated. This material was employed in the degradation of Amaranth azo dye. Individual and interactive effects of operational parameters such as pH, dye concentration and H2O2 dosage on the decolorization efficiency of Amaranth dye were evaluated by 2(3) central composite design. According to characterization techniques, a porous material and a well-crystallized phase of FeWO4 oxide were obtained. Regarding the photo-Fenton reaction assays, up to 97% color and 58% organic carbon removal were achieved in the best experimental conditions. In addition, the photo-Fenton process maintained treatment efficiency over five catalyst reuse cycles to indicate the durability of the FeWO4 catalyst. In summary, the results reveal that the synthesized FeWO4 material is a promising catalyst for wastewater treatment by heterogeneous photo-Fenton process. PMID:26744938

  20. Optimization of Fenton pretreatment for 2-chlorophenol solution

    Institute of Scientific and Technical Information of China (English)

    贺仲兵; 刘云国; 肖玉

    2013-01-01

    Fenton oxidation was used as the pretreatment of 2-chlorophenol wastewater with the objective of dechlorination, as it was considered that after breakage of aryl—Cl bond, the generated intermediates may be easily biodegraded. Hence, the optimization of pH and the low Fenton reagent doses for dechlorination was investigated. More than 99% dechlorination is obtained at the optimal pH 4 and the Fenton reagent doses of 86 mmol/L H2 O2 and 2.87 mmol/L Fe2+. The corresponding 2-chlorophenol is degraded completely, 80.02% COD is also removed, and the biodegradability, evaluated in terms of the BOD5 /COD ratio, is increased up to 0.41. To test the effect of this pretreatment, the pretreated 2-chlorophenol wastewater was fed to a sequencing batch reactor(SBR). The results show that complete mineralization is achieved. It is demonstrated that, for the treatment of recalcitrant compounds like 2-chlorophenol, the Fenton pretreatment could be quite effective and economical for enhancing the biodegradability in a Fenton-biological coupled system.

  1. Treatment of laundrette wastewater using Starbon and Fenton's reagent.

    Science.gov (United States)

    Tony, Maha A; Parker, Helen L; Clark, James H

    2016-09-18

    The use of grey water for a variety of purposes is gaining increased popularity as a means of preserving scarce freshwater resources. In this work, catalytic oxidation over Fenton's reagent and adsorption techniques using Starbon (mesoporous material derived from polysaccharides) has been applied. These novel techniques are used as an alternative to already studied treatments of grey water such as filtration and/or biological processes. In this study, grey water, collected from a commercial laundrette, has been used. Treatment efficiency was determined by changes in the chemical oxygen demand (COD) of the grey water. Experiments using Fenton's reagent at optimum conditions of Fe(3+) = 40 mg L(-1); H2O2 = 400 mg L(-1) and pH 3 were very successful, resulting in a 95% COD removal after 15 min. Treatment with Starbon adsorption was also effective, reaching up to 81% COD removal at pH 3 within 1 h. The combined treatment with Fenton's reagent and Starbon resulted in a 93% COD removal at a significantly reduced concentration of Fenton's reagent compared to the treatment with solo Fenton's reagent. This lower chemical dose has the advantage of reducing costs and lowering sludge generation. PMID:27336472

  2. Three-dimensional homogeneous ferrite-carbon aerogel: one pot fabrication and enhanced electro-Fenton reactivity.

    Science.gov (United States)

    Wang, Yujing; Zhao, Guohua; Chai, Shouning; Zhao, Hongying; Wang, Yanbin

    2013-02-01

    This work focuses on constructing a high catalytic activity cathode of an electro-Fenton system, to overcome the defects of low activity, poor stability, and intricate fabrication of supported catalysts. A series of ferrite-carbon aerogel (FCA) monoliths with different iron/carbon ratios was synthesized directly from metal-resin precursors accompanied by phase transformation. Self-doped ferrite nanocrystals and carbon matrix were formed synchronously via moderate condensation and sol-gel processes, leading to homogeneous texture. An optimal 5% ferric content FCA was composed of coin-like carbon nano-plate with continuous porous structure, and the ferric particles with diameters of dozens of nanometers were uniformly embedded into the carbon framework. The FCA exhibited good conductivity, high catalytic efficiency, and distinguished stability. When it was used as an electro-Fenton cathode, metalaxyl degradation results demonstrated that 98% TOC elimination was realized after 4 h, which was 1.5 times higher than that of the iron oxide supported electrode. It was attributed to self-doped Fe@Fe(2)O(3) ensuring Fe(II) as the mediator, maintaining high activity via reversibe oxidation and reduction by electron transfer among iron species with different valences. Meanwhile, an abundance of independent reaction microspaces were provided for every ferric crystal to in situ decompose electrogenerated H(2)O(2). Moreover, the possible catalytic mechanism was also proposed. The FCA was a promising candidate as potential cathode materials for high-performance electro-Fenton oxidation. PMID:23276222

  3. [Treatment of Petrochemical Treatment Plant Secondary Effluent by Fenton Oxidation].

    Science.gov (United States)

    Wang, Yi; Wu, Chang-yong; Zhou, Yue-xi; Zhang, Xue; Dong, Bo; Chen, Xue-min

    2015-07-01

    Fenton oxidation was applied to treat the petrochemical treatment plant secondary effluent by the continuous flow configuration. The effect of Fenton agent dosage on the COD and phosphorus removal and the variation of the dissolved organic matter characteristics during the treatment process were investigated. The results showed the average COD and PO(4)3- -P concentrations were 64.8 mg.L-1 and 0. 79 mg.L-1, respectively. When the dosage of H2O (30%), FeSO4.7H2O and PAM were 0. 4 mL.L-1, 0. 8 mg.L-1 and 0. 9 mg.L-1 and the residence time was 30 min, the average removal rate of COD and PO(4)3- -P were 24. 3% and 95. 5% respectively. The effluent COD was lower than 50 mg.L-1. The percentage of dissolved organic matters with molecular weight less than 1 x 10(3) was 80. 4% in the raw wastewater, however, the percentage increased to 95. 6% when treated by Fenton oxidation. Three-dimensional fluorescence analysis showed that the Fenton oxidation can effectively remove protein and phenols. GC-MS results showed that there were about 117 kinds of organic matters detected in the secondary effluent, while the number reduced to 27 after oxidation by Fenton. The organics containing unsaturated bond had a better removal than those of other types of organics. Fenton oxidation can be used in the advanced treatment of petrochemical secondary effluent. PMID:26489330

  4. Design of a visible light driven photo-electrochemical/electro-Fenton coupling oxidation system for wastewater treatment

    International Nuclear Information System (INIS)

    Highlights: ► Coupling PEC and EF oxidation significantly improves pollutant degradation efficiency. ► The degradation of the PEC/EF system was increased by 154%. ► The instantaneous current efficiency of the PEC/EF system was increased by 26%. - Abstract: In this study, we report on a photo-electrochemical/electro-Fenton oxidation (PEC/EF) system by coupling visible light driven photo-electrochemical oxidation (PEC) and electro-Fenton oxidation (EF) in an undivided cell. Bi2WO6 nanoplates deposited on FTO glass (Bi2WO6/FTO) and Fe-Fe2O3 core–shell nanowires supported on activated carbon fiber (Fe-Fe2O3/ACF) were used as the anode and the cathode in the PEC/EF system, respectively. This novel PEC/EF system showed much higher activity than the single PEC and EF systems on degradation of rhodamine B in aqueous solution at natural pH. Moreover, the degradation and the instantaneous current efficiencies of the PEC/EF system were increased by 154% and 26% in comparison with the sum of those of single PEC and EF systems, respectively. These significant enhancements could be attributed to the synergetic effect from better separation of photo-generated carriers in the photo-anode and the transfer of photo-electrons to the oxygen diffusion cathode to generate more electro-generated H2O2 and hydroxyl radicals on the Fenton cathode. The better separation of photo-generated carriers contribute more to the overall degradation enhancement than the photo-electrons generated H2O2 and the subsequent Fenton reaction on the cathode during the PEC/EF process.

  5. Design of a visible light driven photo-electrochemical/electro-Fenton coupling oxidation system for wastewater treatment

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Xing [Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079 (China); Ai, Zhihui, E-mail: jennifer.ai@mail.ccnu.edu.cn [Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079 (China); Zhang, Lizhi, E-mail: zhanglz@mail.ccnu.edu.cn [Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079 (China)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer Coupling PEC and EF oxidation significantly improves pollutant degradation efficiency. Black-Right-Pointing-Pointer The degradation of the PEC/EF system was increased by 154%. Black-Right-Pointing-Pointer The instantaneous current efficiency of the PEC/EF system was increased by 26%. - Abstract: In this study, we report on a photo-electrochemical/electro-Fenton oxidation (PEC/EF) system by coupling visible light driven photo-electrochemical oxidation (PEC) and electro-Fenton oxidation (EF) in an undivided cell. Bi{sub 2}WO{sub 6} nanoplates deposited on FTO glass (Bi{sub 2}WO{sub 6}/FTO) and Fe-Fe{sub 2}O{sub 3} core-shell nanowires supported on activated carbon fiber (Fe-Fe{sub 2}O{sub 3}/ACF) were used as the anode and the cathode in the PEC/EF system, respectively. This novel PEC/EF system showed much higher activity than the single PEC and EF systems on degradation of rhodamine B in aqueous solution at natural pH. Moreover, the degradation and the instantaneous current efficiencies of the PEC/EF system were increased by 154% and 26% in comparison with the sum of those of single PEC and EF systems, respectively. These significant enhancements could be attributed to the synergetic effect from better separation of photo-generated carriers in the photo-anode and the transfer of photo-electrons to the oxygen diffusion cathode to generate more electro-generated H{sub 2}O{sub 2} and hydroxyl radicals on the Fenton cathode. The better separation of photo-generated carriers contribute more to the overall degradation enhancement than the photo-electrons generated H{sub 2}O{sub 2} and the subsequent Fenton reaction on the cathode during the PEC/EF process.

  6. Integration of processes induced air flotation and photo-Fenton for treatment of residual waters contaminated with xylene

    International Nuclear Information System (INIS)

    Highlights: ► We have studied the treatment of wastewater contaminated with hydrocarbons represented by the xylene, using these processes in an integrated mode: induced air flotation and photo-Fenton. ► We have selected xylene as representative contaminant due to properties of toxicity, solubility in water and vapor pressure. ► The manuscript presents a series of accurate experimental data that can be useful for material and energy optimization purposes in the xylene removal aiming the treatment of oil field produced water. - Abstract: Produced water in oil fields is one of the main sources of wastewater generated in the industry. It contains several organic compounds, such as benzene, toluene, ethyl benzene and xylene (BTEX), whose disposal is regulated by law. The aim of this study is to investigate a treatment of produced water integrating two processes, i.e., induced air flotation (IAF) and photo-Fenton. The experiments were conducted in a column flotation and annular lamp reactor for flotation and photodegradation steps, respectively. The first order kinetic constant of IAF for the wastewater studied was determined to be 0.1765 min−1 for the surfactant EO 7. Degradation efficiencies of organic loading were assessed using factorial planning. Statistical data analysis shows that H2O2 concentration is a determining factor in process efficiency. Degradations above 90% were reached in all cases after 90 min of reaction, attaining 100% mineralization in the optimized concentrations of Fenton reagents. Process integration was adequate with 100% organic load removal in 20 min. The results of the integration of the IAF with the photo-Fenton allowed to meet the effluent limits established by Brazilian legislation for disposal.

  7. Preparation of FeCeOx by ultrasonic impregnation method for heterogeneous Fenton degradation of diclofenac.

    Science.gov (United States)

    Chong, Shan; Zhang, Guangming; Zhang, Nan; Liu, Yucan; Zhu, Jia; Huang, Ting; Fang, Shunyan

    2016-09-01

    FeCeOx has been successfully synthesized by ultrasonic impregnation method and applied in diclofenac removal in heterogeneous Fenton process. The effects of ultrasonic density, impregnation time, mole ratio of Fe and Ce and calcination temperature were investigated. Nitrogen adsorption/desorption, SEM, XRD, HRTEM, Raman and XPS analyses were characterized. Stability and reusability of FeCeOx were evaluated. The results indicated that 83% degradation efficiency of diclofenac was achieved by FeCeOx under the optimum preparation conditions. Fe ions were distributed uniformly in crystal structure and the solid solution structure of FeCeOx with a lattice constriction was formed. Exposed crystalline plane (200) with a relatively high surface energy may be the main reason to provide high catalytic activity of FeCeOx. Oxygen vacancies took part in catalytic process and a portion of them were oxidized after reaction. FeCeOx showed an excellent chemical stability and reusability in heterogeneous Fenton process. PMID:27150766

  8. A mechanistic kinetic model for phenol degradation by the Fenton process

    International Nuclear Information System (INIS)

    The objective of this paper is to develop and validate a mechanistic model for the degradation of phenol by the Fenton process. Experiments were performed in semi-batch operation, in which phenol, catechol and hydroquinone concentrations were measured. Using the methodology described in Pontes and Pinto [R.F.F. Pontes, J.M. Pinto, Analysis of integrated kinetic and flow models for anaerobic digesters, Chemical Engineering Journal 122 (1-2) (2006) 65-80], a stoichiometric model was first developed, with 53 reactions and 26 compounds, followed by the corresponding kinetic model. Sensitivity analysis was performed to determine the most influential kinetic parameters of the model that were estimated with the obtained experimental results. The adjusted model was used to analyze the impact of the initial concentration and flow rate of reactants on the efficiency of the Fenton process to degrade phenol. Moreover, the model was applied to evaluate the treatment cost of wastewater contaminated with phenol in order to meet environmental standards.

  9. Monitoring ecotoxicity of disperse red 1 dye during photo-Fenton degradation.

    Science.gov (United States)

    da Silva Leite, Laís; de Souza Maselli, Bianca; de Aragão Umbuzeiro, Gisela; Pupo Nogueira, Raquel F

    2016-04-01

    The present work assessed the ecotoxicity of the commercially available form of the azo dye Disperse Red 1 (DR1) and the main degradation products generated during photo-Fenton degradation. The acute toxicity tests with the microcrustacean Daphnia similis showed that toxicity increased after 10 min of treatment, when 35% of the original concentration of the dye has been degraded but without decrease in total organic carbon concentration (TOC). The increase of toxicity was a consequence of generation of degradation products of higher toxicity than DR1, which achieved maximum concentration after 10 min reaction. The structures identified using LC/MS indicated that most of the intermediates were formed after addition of hydroxyl radical to benzenic ring but the cleavage of azo bond was also observed. The intermediates were further degraded and toxicity was then reduced to non toxic levels after 45 min experiment, when 98% of the initial concentration of DR1 was degraded and mineralization achieved 55%. The results of this study showed that the textile dye DR1 can be degraded by photo-Fenton process with removal of acute toxicity to D. similis even with incomplete mineralization. PMID:26841294

  10. Removal of organic pollutants in tannery wastewater from wet-blue fur processing by integrated Anoxic/Oxic (A/O) and Fenton: Process optimization

    DEFF Research Database (Denmark)

    Wang, Yong; Li, Weiguang; Angelidaki, Irini;

    2014-01-01

    Treatment of tannery wastewater has been a challenge in remediation of aquatic environment in developing countries. Removal of organic pollutants in tannery wastewater from wet-blue fur processing was studied using integrated processes of Anoxic/Oxic and Fenton. Analysis of COD composition based on...... 80%. In the subsequent Fenton oxidation, effects of initial pH and H2O2 dose on COD removal were investigated, and response surface methodology was adopted to obtain the optimal conditions as initial pH of 4.0, H2O2 dose of 14.0mM, H2O2:Fe2+ molar ratio of 10.6, and reaction time of 3h to achieve the...... highest COD removal of 55.87%. GC-MS analysis was carried out to observe the change of organic composition during Fenton oxidation, and most of the residual organic pollutants resistant to Fenton treatment belonged to organosilanes and saturated alkanes. This study will provide useful information for...

  11. Evaluation of Fenton method and ozone-based processes for colour and organic matter removal from biologically pre-treated swine manure.

    Science.gov (United States)

    Riaño, Berta; Coca, Mónica; García-González, Mari Cruz

    2014-12-01

    This work evaluates the efficiency of different advanced oxidation processes (Fenton method, O3, H2O2 and O3/H2O2) for removing total COD (TCOD) and colour from biologically pre-treated swine manure. The Fenton process with a dosage of 100 mg L(-1) of Fe(2+) and 800 mg L(-1) of H2O2 resulted in about 78% TCOD and 96% colour reductions at an initial pH=3 after a reaction time of 30 min. Coagulation, rather than oxidation process, was identified as a crucial mechanism for removing pollutants. Otherwise, single ozonation achieved only 27-30% TCOD and 53-88% colour removals for ozone dosages ranging between 0.7 and 4.3 g O3 h(-1) at the original wastewater pH (pH=8.1) after 30 min reaction time. The combined treatment with O3/H2O2 at pH=8.1 did not produce any significant TCOD or colour reduction improvement. Therefore, direct reactions with ozone rather than radical reactions were elucidated as the main removal mechanisms in the ozone-based processes. Finally, a rough estimation of the operational costs involved in each process was also performed to compare their economic feasibility. The findings suggested that the Fenton process was more suitable than ozonation for reducing TCOD and colour from the biologically pre-treated swine manure. PMID:25058844

  12. Water quality in the vicinity of Fenton Hill, 1987 and 1988. [Fenton Hill site

    Energy Technology Data Exchange (ETDEWEB)

    Purtymun, W.D.; Ferenbaugh, R.W.; Maes, M.N.; Williams, M.C.

    1991-03-01

    Water-quality data have been collected since 1974 from established surface- and ground-water stations at, and in the vicinity of, Fenton Hill (site of the Laboratory's Hot Dry Rock Geothermal Project). The site is located on the southwest edge of the Valles Caldera in the Jemez Mountains. To determine the chemical quality of water, data were collected in 1987 and 1988 from 13 surface-water stations and 19 ground-water stations. The classification of the water quality is made on the basis of predominated ions and total dissolved solids. There are four classifications of surface water (sodium and chloride, calcium and bicarbonate, calcium and sulfate, and sodium and bicarbonate) and three classifications of ground water (sodium and chloride, calcium and bicarbonate, and sodium and bicarbonate). Variations in the chemical quality of the surface and ground water in 1987 and 1988 are apparent when data are compared with each other and with previous analyses. These variations are not considered significant, as they are in the range of normal seasonal changes. Cumulative production since 1976 from the supply well at Fenton Hill has been about 63 {times} 10{sup 6} gal, with a decline in the water level of the well of about 14 ft, or about 1.4 ft/yr. The aquifer penetrated by the well is still capable of reliable supply to the site for a number of years, based on past production. The quality of water from the well has deteriorated slightly; however, the water quality is in compliance with drinking water standards. The effects of discharge from the storage ponds into an adjacent canyon have been monitored by trace metal analyses of vegetation and soil. The study indicates minimal effects, which will be undetectable in a few years if there are no further releases of effluents into the canyon. 19 refs., 6 figs., 3 tabs.

  13. Effects of the Fenton reagent on transport in yeast

    Czech Academy of Sciences Publication Activity Database

    Khansuwan, U.; Kotyk, Arnošt

    2000-01-01

    Roč. 45, č. 6 (2000), s. 515-520. ISSN 0015-5632 R&D Projects: GA ČR GA204/98/0474 Institutional research plan: CEZ:AV0Z5011922 Keywords : Fenton reagent * yeast Subject RIV: CD - Macromolecular Chemistry Impact factor: 0.752, year: 2000

  14. A parametric study on the decolorization and mineralization of C.I. Reactive Red 141 in water by heterogeneous Fenton-like oxidation over FeZSM-5 zeolite

    OpenAIRE

    Yaman, Ceyda; GÜNDÜZ*, Gönül

    2015-01-01

    In this study, the heterogeneous Fenton-like degradation of Reactive Red 141 (RR141) in water was investigated over iron containing ZSM-5 zeolite (Si/Al = 42) prepared by ion-exchange (FeZSM-5 (42)). The catalyst was characterized by XRD, SEM, FTIR, TPR, and ICP-AES measurements. The effects of the initial concentrations of the dye and H2O2, the initial pH of the solution, catalyst loading, and the reaction temperature were investigated on heterogeneous Fenton-like degradation of RR141. The r...

  15. Determining the optimal dose of Fenton reagent in a leachate treatment by Fenton-adsorption; Determinacion de la dosis optima de reactivo Fenton en un tratamiento de lixiviados por Fenton-adsorcion

    Energy Technology Data Exchange (ETDEWEB)

    Mendez Novelo, Roger Ivan; Pietrogiovanna Bronca, Jose Alfredo; Santos Ocampo, Beatriz; Sauri Riancho, Maria Rosa; Giacoman Vallejos, German; Castillo Borges, Elba Rene [Universidad Autonoma de Yucatan, Facultad de Ingenieria, Merida, Yucatan (Mexico)]. E-mail: mnovelo@uady.mx

    2010-07-01

    Leachates are formed as a result of the percolation of liquids, through the solid wastes in stabilization process. Their composition is variable and highly toxic; therefore, leachates treatment is a complex task. Due to the high permeability of the soil of the Yucatan Peninsula leachates represent a high risk to health. Fenton type oxidation and adsorption treatment have been tested, and they have showed better results than other types of biological or physicochemical treatment. Fenton process consists in treating the contaminant load with a combination of H{sub 2}O{sub 2} and FeSO{sub 4} under acidic conditions. Experiments were conducted in order to determine if filtration was better than the sedimentation of the sludges. The optimum contact time and the best relations [Fe{sup 2+}]/[H{sub 2}O{sub 2}] and [COD]/[H{sub 2}O{sub 2}] were determined. Subsequently, the oxidized samples were filtered and the adsorption process was tested using two columns in series packed with activated carbon. It was concluded that the sludge generated by the Fenton process was removed more efficiently through filtration than sedimentation. Optimal contact times were 5 min for COD removal, and 1 hour for colour removal; process time was set to one hour in order to protect the activated carbon. The best relations for [Fe{sup 2+}]/[H{sub 2}O{sub 2}] and [COD]/[H{sub 2}O{sub 2}] were 0.6 and 9 respectively. The maximum removal efficiency after the adsorption process was 98.9% for COD and 100% for colour at zero time of the column. A final biodegradability index of 0.24 was reached after the Fenton-adsorption tests. [Spanish] Los lixiviados son el resultado de la percolacion de liquidos a traves de los desechos solidos en proceso de estabilizacion. La complejidad de su tratamiento se debe a que su composicion es altamente toxica y variable. Lo anterior y el suelo altamente permeable de la peninsula de Yucatan, representan un alto peligro a la salud. Se ensayo un tratamiento de oxidacion

  16. Fenton Processes as an Alternative to the Removal of Endocrine Disruptors and other Environmental Pollutants [Processos Fenton como Alternativa na Remoção de Interferentes Endócrinos e outros Micropoluentes Ambientais

    Directory of Open Access Journals (Sweden)

    Mariana Roberto Gama

    2012-11-01

    Full Text Available Technological advances, combined to high levels of consumption by the population, led to an increase in the generation of waste, which compromise the availability of natural resources, especially water resources. Furthermore, sensitive analytical detections have increased the detection of environmental micropollutants, many highly toxic. Therefore, the search for alternatives to the removal of micropollutants from water is necessary to overcome the methods currently available. Advanced oxidative processes are efficient for the removal of micropollutants. This review summarizes the main aspects of environmental contamination by endocrine disruptors and the use of Fenton reactions as advanced oxidation processes in the removal of these micropollutants.

  17. Review of iron-free Fenton-like systems for activating H{sub 2}O{sub 2} in advanced oxidation processes

    Energy Technology Data Exchange (ETDEWEB)

    Bokare, Alok D.; Choi, Wonyong, E-mail: wchoi@postech.edu

    2014-06-30

    Graphical abstract: - Highlights: • Elements with multiple redox states efficiently decompose H{sub 2}O{sub 2} at neutral pH. • Activation of H{sub 2}O{sub 2} is entirely governed by solution pH and catalyst composition. • Metal leaching and toxicity is an important factor for practical applications. • Iron-free Fenton systems work only in specialized reaction conditions. - Abstract: Iron-catalyzed hydrogen peroxide decomposition for in situ generation of hydroxyl radicals (HO{sup •} ) has been extensively developed as advanced oxidation processes (AOPs) for environmental applications. A variety of catalytic iron species constituting metal salts (in Fe{sup 2+} or Fe{sup 3+} form), metal oxides (e.g., Fe{sub 2}O{sub 3}, Fe{sub 3}O{sub 4}), and zero-valent metal (Fe{sup 0}) have been exploited for chemical (classical Fenton), photochemical (photo-Fenton) and electrochemical (electro-Fenton) degradation pathways. However, the requirement of strict acidic conditions to prevent iron precipitation still remains the bottleneck for iron-based AOPs. In this article, we present a thorough review of alternative non-iron Fenton catalysts and their reactivity towards hydrogen peroxide activation. Elements with multiple redox states (like chromium, cerium, copper, cobalt, manganese and ruthenium) all directly decompose H{sub 2}O{sub 2} into HO{sup •} through conventional Fenton-like pathways. The in situ formation of H{sub 2}O{sub 2} and decomposition into HO{sup •} can be also achieved using electron transfer mechanism in zero-valent aluminum/O{sub 2} system. Although these Fenton systems (except aluminum) work efficiently even at neutral pH, the H{sub 2}O{sub 2} activation mechanism is very specific to the nature of the catalyst and critically depends on its composition. This review describes in detail the complex mechanisms and emphasizes on practical limitations influencing their environmental applications.

  18. The removal of COD and color by Fenton oxidation from leachate of Erzurum municipal solid waste landfill

    Science.gov (United States)

    Kocakaplan, Nihal; Ertugay, Neşe; Malkoç, Emine

    2016-04-01

    The optimal conditions for treatment of leachate were determined as pH = 2.5, Fe2+= 2 mg/L and H2O2= 100 mg/L. Under the optimal conditions, approximately 90% color (at 620 nm), 84% color (at 525 nm), 74% color (at 436 nm) and 47.8% COD removal efficiency from leachate were achieved after 20 min of reaction. Depending on the results obtained experiments, Fenton process has been used successfully in removal of COD and color in landfill leachate.

  19. A study on removal of elemental mercury in flue gas using fenton solution

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yangxian; Wang, Yan; Wang, Qian; Pan, Jianfeng [School of Energy and Power Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013 (China); Zhang, Yongchun [Jiangsu Province Special Equipment Safety Supervision Inspection Institute (Branch of Wuxi), Wuxi 214000 (China); Zhou, Jianfei [School of Energy and Power Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013 (China); Zhang, Jun [Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, Southeast University, Nanjing 210096 (China)

    2015-07-15

    Highlights: • A novel technique on oxidation of Hg{sup 0} using Fenton was proposed. • The effects of several process parameters on Hg{sup 0} removal were studied. • Products and ·OH in solution were detected. • Reaction mechanism of Hg{sup 0} removal was studied. • Simultaneous removal of Hg{sup 0}, NO and SO{sub 2} was also studied. - Abstract: A novel technique on oxidation-separation of elemental mercury (Hg{sup 0}) in flue gas using Fenton solution in a bubbling reactor was proposed. The effects of several process parameters (H{sub 2}O{sub 2} concentration, Hg{sup 0} inlet concentration, Fe{sup 2+} concentration, solution temperature, solution pH, gas flow) and several flue gas components (NO, SO{sub 2}, O{sub 2}, CO{sub 2}, inorganic ions and particulate matters on Hg{sup 0} removal were studied. The results indicate that H{sub 2}O{sub 2} concentration, Fe{sup 2+} concentration, solution pH and gas flow have great effects on Hg{sup 0} removal. Solution temperature, Hg{sup 0}, NO, SO{sub 2}, CO{sub 3}{sup 2−} and HCO{sub 3}{sup −} concentrations also have significant effects on Hg{sup 0} removal. However, Cl{sup −}, SO{sub 4}{sup 2−}, NO{sub 3}{sup −}, O{sub 2} and CO{sub 2} concentrations only have slight effects on Hg{sup 0} removal. Furthermore, reaction mechanism of Hg{sup 0} removal and simultaneous removal process of Hg{sup 0}, NO and SO{sub 2} were also studied. Hg{sup 0} is removed by oxidation of ·OH and oxidation of H{sub 2}O{sub 2}. The simultaneous removal efficiencies of 100% for SO{sub 2}, 100% for Hg{sup 0} and 88.3% for NO were obtained under optimal test conditions. The results demonstrated the feasibility of Hg{sup 0} removal and simultaneous removal of Hg{sup 0}, SO{sub 2} and NO using Fenton solution in a bubbling reactor.

  20. Removal of COD from olive mill wastewater by Fenton's reagent: Kinetic study

    International Nuclear Information System (INIS)

    This work describes the application of Fenton's reagent (H2O2/Fe2+) to the removal of chemical oxygen demand (COD) from olive mill wastewater (OMW) in a laboratory-scale batch reactor. The effect of different operational conditions, namely, hydrogen peroxide and ferrous ion concentrations, temperature and initial pH were evaluated. ORP, pH and dissolved oxygen were on-line monitored. Working with an initial pH equal to 3.5, a temperature of 30 deg. C, a molar ratio H2O2/Fe2+ = 15 and a weight ratio R = H2O2/COD = 1.75 makes possible a COD conversion of 70%. A kinetic study was carried out using a modified pseudo-first-order model. The experiments performed at different temperatures allowed the calculation of the Arrhenius equation parameters and the global activation energy for the pseudo-first-order reaction (28.2 kJ/mol).

  1. Fenton oxidative decolorization of the azo dye Direct Blue 15 in aqueous solution

    DEFF Research Database (Denmark)

    Sun, Jian-Hui; Shi, Shao-Hui; Lee, Yi-Fan;

    2009-01-01

    kinetic of the DB15 were studied, the operating parameters were preferred by changing one factor at one time while the other parameters were kept constant. The optimal conditions for the decolorization of DB15 were determined as pH=4.0, [H2O2] = 2.8x10(-3) mol/L, H2O2/Fe2+ ratio = 100: 1, H2O2/dye ratio...... the reaction temperature from 20 to 40 degrees C showed a positive effect on the decolorization efficiency of DB15. The present study can provide guidance to relational industry operators and planners to effectively treat the DB15 contaminated wastewater by Fenton oxidation process. (C) 2009 Elsevier...

  2. Fenton 氧化法预处理高浓度制药废水的实验研究%The Experimental Study on the Fenton Oxidation Pretreatment of High Concentration Pharmaceutical Wastewater

    Institute of Scientific and Technical Information of China (English)

    王会芳; 杨瑞洪

    2014-01-01

    The high concentration pharmaceutical wastewater was pretreated by Fenton method , the influence of Fenton reagent oxidation pretreatment of high concentration pharmaceutical wastewater was studied.The effect on COD Cr treatment of pharmaceutical wastewater was discussed , the influence factor included the value of pH , the dosage of FeSO 4 · 7H2 O, and reaction time on Fenton oxidation.The experimental results showed that the pH value was 4, the reaction time was 100 min, the dosage of FeSO4 · 7H2O was 0.024 mol/L, the dosage ratio of H2O2/Fe2+was 11:1, the CODCr removal was 52.1%, and the biodegradability of the BOD/COD was 0.57.Under this condition , the effect was the most ideal.%采用Fenton法对高浓度制药废水进行预处理实验。主要考察了Fenton试剂氧化法预处理高浓度制药废水的影响因素,主要讨论pH值、 FeSO4·7H2 O投加量、反应时间对Fenton氧化工艺对制药废水中CODCr处理效果的影响。实验结果显示, pH值为4、反应时间100 min、 FeSO4·7H2 O投加量为0.024 mol/L、 H2 O2/Fe2+投加比为11:1, CODCr处理去除率为52.1%,可生化性BOD/COD为0.57,效果最为理想。

  3. Effect of iron ion on doxycycline photocatalytic and Fenton-based autocatatalytic decomposition.

    Science.gov (United States)

    Bolobajev, Juri; Trapido, Marina; Goi, Anna

    2016-06-01

    Doxycycline plays a key role in Fe(III)-to-Fe(II) redox cycling and therefore in controlling the overall reaction rate of the Fenton-based process (H2O2/Fe(III)). This highlights the autocatalytic profile of doxycycline degradation. Ferric iron reduction in the presence of doxycycline relied on doxycycline-to-Fe(III) complex formation with an ensuing reductive release of Fe(II). The lower ratio of OH-to-contaminant in an initial H2O2/Fe(III) oxidation step than in that of classical Fenton (H2O2/Fe(II)) decreased the doxycycline degradation rate. The quantum yield of doxycycline in direct UV-C photolysis was 3.1 × 10(-3) M E(-1). In spite of doxycycline-Fe(III) complexes could produce the adverse effect on the doxycycline degradation in the UV/Fe(III) system some acceleration of the rate was observed upon irradiation of the Fe(III)-hydroxy complex. Acidic reaction media (pH 3.0) and the molar ratio of DC/Fe(III) = 2/1 favored the complex formation. Doxycycline close degradation rates and complete mineralization achieved for 120 min (Table 1) with both UV/H2O2 and UV/H2O2/Fe(III) indicated the unsubstantial role of the reduction of Fe(III) to Fe(II) in UV/H2O2/Fe(III) system efficacy. Thus, factors such as doxycycline's ability to form complexes with ferric iron and the ability of complexes to participate in a reductive pathway should be considered at a technological level in process optimization, with chemistry based on iron ion catalysis to enhance the doxycycline oxidative pathway. PMID:27016818

  4. Stimulation of production of reactive oxygen and nitrogen species in endothelial cells by unmodified and Fenton-modified ultradisperse detonation diamond.

    Science.gov (United States)

    Solarska-Ściuk, K; Gajewska, A; Skolimowski, J; Mitura, K; Bartosz, G

    2013-01-01

    In recent years, the development of nanotechnology opens up new prospects for biomedical applications of unmodified and chemically modified diamond nanoparticles (DNPs). The problem of biocompatibility of DNPs is thus of primary importance. The first step in the modification of DNPs is usually the introduction of -OH groups, which can bind other functional groups. One of the basic methods to introduce -OH groups onto DNPs is the Fenton reaction. The aim of this study was to compare the effect of unmodified DNPs and nanoparticles modified by the Fenton reaction on human endothelial cells. Ultradisperse diamond (UDD) was modified by the Fenton reaction introducing surface -OH groups. Immortalized human umbilical cord endothelial cells (HUVEC-ST) were incubated with 2-100 µg/mL nanopowders in the opti-MEM medium. For comparison, graphite powder (GRAF and GRAF+OH) was also employed. UDD and GRAF augmented generation of reactive oxygen species in the cells after 24 H incubation, estimated by oxidation of 2',7'-dichlorofluorescin diacetate (H2DCF-DA). Cellular production of nitric oxide, estimated with DAF-FM-DA (3-amino-4-aminomethyl 2',7'-dichlorofluorescein diacetate), was also affected by UDD and GRAF after 24 H. Fenton-modified OH, in contrast to unmodified diamond, decreased NO production. Detonation nanoparticles also affected the cellular content of glutathione and activities of main antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, and glutathione S-transferase). This article was published online on 5 February 2013. Errors in the byline and affiliation line were subsequently identified. This notice is included in the online and print versions to indicate that both have been corrected 18 April 2013. PMID:23586587

  5. Assessment of PCDD/Fs formation in the Fenton oxidation of 2-chlorophenol: Influence of the iron dose applied.

    Science.gov (United States)

    Vallejo, Marta; Fernández-Castro, Pablo; San Román, M Fresnedo; Ortiz, Inmaculada

    2015-10-01

    Toxic polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) may be formed during remediation of chlorinated phenols via Fenton oxidation. To highlight the need for monitoring the production of toxic byproducts in these reactions, this work assessed the influence of iron dose (0.09-0.36 mM) on the Fenton oxidation of 2-chlorophenol (2-CP, 15.56 mM), a potential precursor of PCDD/Fs, by quantifying 2-CP removal and mineralization rates as well as byproducts yields, including PCDD/Fs. Although the increase in the iron dose showed positive contribution to 2-CP oxidation, under the operating conditions of the current study (H2O2 at 20% of the stoichiometric dose and 20 °C), there was no effect on the mineralization rate, and TOC and chlorine balances were far to be closed, depicting the presence of chlorinated organic byproducts in the reaction medium. After 4 h of treatment, the total PCDD/Fs concentrations increased by 14.5-39 times related to the untreated sample when the iron doses tested decreased from 0.36 to 0.09 mM, with preferential formation of PCDFs over PCDDs and dominance of lower chlorinated congeners such as tetra and penta-PCDD/Fs. The treatment with the highest iron dose (0.36 mM) exhibited the lowest PCDD/Fs yields and was thus most successful at mitigating toxic byproducts of the Fenton oxidation, leading to lower sample toxic equivalence (TEQ) value. PMID:26134538

  6. AbstractApplication of Fenton-like process using iron nano oxides for pyrene removal from contaminated soils

    Directory of Open Access Journals (Sweden)

    S. Jorfi

    2014-05-01

    Conclusion: Fenton oxidation using iron nano oxides under defined optimum conditions and neutral pH, can be a suitable alternative to conventional Fenton for remediation of soils contaminated with pyrene.

  7. Fenton-treated functionalized diamond nanoparticles as gene delivery system.

    Science.gov (United States)

    Martín, Roberto; Alvaro, Mercedes; Herance, José Raúl; García, Hermenegildo

    2010-01-26

    When raw diamond nanoparticles (Dnp, 7 nm average particle size) obtained from detonation are submitted to harsh Fenton-treatment, the resulting material becomes free of amorphous soot matter and the process maintains the crystallinity, reduces the particle size (4 nm average particle size), increases the surface OH population, and increases water solubility. All these changes are beneficial for subsequent Dnp covalent functionalization and for the ability of Dnp to cross cell membranes. Fenton-treated Dnps have been functionalized with thionine and the resulting sample has been observed in HeLa cell nuclei. A triethylammonium-functionalized Dnp pairs electrostatically with a plasmid having the green fluorescent protein gene and acts as gene delivery system permitting the plasmid to cross HeLa cell membrane, something that does not occur for the plasmid alone without assistance of polycationic Dnp. PMID:20047335

  8. Alternate switching between microbial fuel cell and microbial electrolysis cell operation as a new method to control H2O2 level in Bioelectro-Fenton system

    DEFF Research Database (Denmark)

    Zhang, Yifeng; Wang, Yong; Angelidaki, Irini

    2015-01-01

    Sustainable H2O2 supply and cost-effective elimination of residual H2O2 are two key challenges associated with the successful application of Fenton reaction for contaminant removal. In this study, an innovative Bioelectro-Fenton system capable of alternate switching between microbial electrolysis...... by switching the system to MFC mode of operation. Complete decolorization and mineralization of 50 mg L−1 methylene blue (MB) was achieved in the MEC mode with apparent first order rate constants of 0.43 and 0.22 h−1, respectively. After switching to the MFC mode, residual H2O2 of 180 mg L−1 was removed...... a proof-in-concept new system for efficient and cost-effective H2O2 control and recalcitrant pollutants removal....

  9. Photo-fenton remediation of wastewaters containing agrochemicals

    OpenAIRE

    Antonio Carlos Silva Costa Teixeira; Lucas Mendes; Giselle Stollar; Roberto Guardani; Cláudio Augusto Oller do Nascimento

    2005-01-01

    The photochemical degradation of agrochemicals in aqueous solution by means of advanced oxidation processes (AOPs) was studied. The photo-Fenton process was evaluated in terms of the time evolution of dissolved organic carbon (COD) and chemical oxygen demand (DOC), their total removals, and increase in biodegradability of treated wastewater. Under the experimental conditions studied, the process showed to be superior to other AOPs, at any Fe(II) and H2O2 concentrations. The results pointed to...

  10. Stability and performance enhancements of Electrokinetic-Fenton soil remediation

    OpenAIRE

    Ng, Y. S.; Sen Gupta, B; Hashim, M A

    2014-01-01

    Electrokinetic process is a potential in situ soil remediation process which transports the contaminants via electromigration and electroosmosis. For organic compounds contaminated soil, Fenton’s reagent is utilized as a flushing agent in electrokinetic process (Electrokinetic-Fenton) so that removal of organic contaminants could be achieved by in situ oxidation/destruction. However, this process is not applied widely in industries as the stability issue for Fenton’s reagent is the main drawb...

  11. COD Removal of Different Industrial Wastewater by Fenton Oxidation Process

    OpenAIRE

    Yogita Sindhi*1

    2014-01-01

    Advanced oxidation processes are possibly one of the most effective methods for the treatment of wastewater containing organic products (effluents from chemical and agrochemical industries, the textile industry, paints, dyes, etc.).Fenton process is a one of advanced oxidation process. Fenton’s process have been extensively used for the removal of COD, TOC, dyes, phenolic compounds other organic chemicals from industrial and municipal wastewater. In this study, the laboratory s...

  12. Heterogeneous photo-Fenton photodegradation of reactive brilliant orange X-GN over iron-pillared montmorillonite under visible irradiation

    International Nuclear Information System (INIS)

    Decolorization and mineralization of reactive brilliant orange X-GN was investigated under visible light irradiation (λ ≥ 420 nm) by using Fe-Mt/H2O2 as the heterogeneous photo-Fenton reagent. The characterization results (XRD, FTIR, XRF, BET, XPS, UV-vis diffuse spectra) of Fe-Mt suggested that small-sized hydrolyzed iron successfully intercalated into the interlayer spaces of the clay via pillaring. The stability of the Fe-Mt catalyst was evaluated according to the decolorization efficiency for X-GN with used catalyst from previous runs and the concentration of iron ions leached from the solid structure into the reaction solution. The catalytic results showed that at a reaction temperature of 30 deg. C, pH 3.0, 4.9 mmol/L H2O2 and 0.6 g/L catalyst dosage, 98.6% discoloration and 52.9% TOC removal of X-GN were achieved under visible irradiation after 140 min treatment. Furthermore, the maximum concentration of dissolved iron ions was 1.26% of the total iron content in the Fe-Mt catalyst after photocatalysis. A halogen lamp as light source has demonstrated that visible radiation can be successfully used for a heterogeneous photo-Fenton process.

  13. Optimization of the Parameters Affecting the Fenton Process for Decolorization of Reactive Red 198 (RR-198 from the Aqueous Phase

    Directory of Open Access Journals (Sweden)

    Mansooreh Dehghani

    2015-10-01

    Full Text Available Background: Recently, there has been a great concern about the consumption of dyes because of their toxicity, mutagenicity, carcinogenicity, and persistence in the aquatic environment. Reactive dyes are widely used in textile industry. Advanced oxidation processes are one of the cost-effective methods for the removal of these dyes. The main aims of this study were determining the feasibility of using Fenton process in removing Reactive Red 198 (RR-198 dye from aqueous solution and determining the optimal conditions. Methods: This is a cross-sectional study conducted at a laboratory scale. A total of 69 samples were considered and the effect of pH, Fe (II concentration, H2O2 concentration, initial dye concentration and reaction time were investigated. Results: According to the results, a maximum removal efficiency of 92% was obtained at pH of 3 and the reaction time of 90 min; also, the concentration of Fe (II, H2O2, initial dye concentration were 100 mg/L, 50 mg/L, and 100 mg/L, respectively. The results revealed that by increasing the concentration of Fe (II, H2O2 and initial dye, the removal efficiency was increased. Conclusions: The results showed that Fenton process could be used as a cost-effective method for removing RR-198 dye from textile wastewater efficiently.

  14. Treatment of pharmaceutical wastewater using interior micro-electrolysis/Fenton oxidation-coagulation and biological degradation.

    Science.gov (United States)

    Xu, Xiaoyi; Cheng, Yao; Zhang, Tingting; Ji, Fangying; Xu, Xuan

    2016-06-01

    The synthesis of steroid hormones produces wastewater that is difficult to manage and characterize due to its complex components and high levels of toxicity and bio-refractory compounds. In this work, interior micro-electrolysis (IME) and Fenton oxidation-coagulation (FOC) were investigated as wastewater pretreatment processes in combination with biological treatments using a hydrolysis acidification unit (HA) and two-stage biological contact oxidation (BCO) in laboratory and field experiments. In laboratory experiments with an average initial COD load of about 15,000 mg/L, pH of 4, Fe-C/water (V/V) ratio of 1:1, air/water ratio of 10, and reaction time of 180 min, IME achieved a COD removal efficiency of 31.8% and a 1.7-fold increase in the BOD5/COD (B/C) ratio of wastewater. The Fe(2+) concentration of 458.5 mg/L in the IME effluent meets the requirements of the Fenton oxidation (FO) process. FOC further reduced the COD with an efficiency of 30.1%, and the B/C ratio of the wastewater reached 0.59. Excitation-emission matrix (EEM) analysis showed that complex higher molecular weight organic compounds in the wastewater were degraded after the pretreatment process. In addition, a field experiment with a continuous flow of 96 m(3)/d was conducted for over 90 d. The combined process system operated steadily, though the Fe-C fillings should be soaked in a sulfuric acid solution (5‰) for 12 h to recover activity every two weeks. The COD and BOD5 concentrations in the final effluent were less than 90 mg/L and 15 mg/L, respectively. PMID:26953729

  15. Electrokinetic-Fenton technology for the remediation of hydrocarbons historically polluted sites.

    Science.gov (United States)

    Sandu, Ciprian; Popescu, Marius; Rosales, Emilio; Bocos, Elvira; Pazos, Marta; Lazar, Gabriel; Sanromán, M Angeles

    2016-08-01

    The feasibility of the electrokinetic-Fenton technology coupled with surfactants in the treatment of real historically hydrocarbons polluted soils has been studied. The characterisation of these soils from Spain and Romania was performed and identified as diesel and diesel-motor oil spillages, respectively. Moreover, the ageing of the spillages produced by the soil contamination was estimated showing the historical pollution of the sites (around 11 and 20 years for Romanian and Spanish soils, respectively). An ex-situ electrochemical treatment was performed to evaluate the adequacy of surfactants for the degradation of the hydrocarbons present in the soils. It was found an enhancement in the solubilisation and removal of TPHs with percentages increasing from 25.7 to 81.8% by the presence of Tween 80 for Spanish soil and from 15.1% to 71.6% for Triton X100 in Romanian soil. Therefore, the viability of coupling enhanced electrokinetic and Fenton remediation was evaluated through a simulated in-situ treatment at laboratory scale. The results demonstrated that the addition of the selected surfactants improved the solubilisation of the hydrocarbons and influenced the electroosmotic flow with a slight decrease. The efficiency of the treatment increased for both considered soil samples and a significant degradation level of the hydrocarbons compounds was observed. Buffering of pH coupled with the addition of a complexing agent showed to be important in the treatment process, facilitating the conditions for the degradation reactions that take place into the soil matrix. The results demonstrated the effectiveness of the selected techniques for remediation of the investigated soils. PMID:27183337

  16. [Degradation of phenol with a Fe/cu-catalytic heterogeneous-Fenton process].

    Science.gov (United States)

    Yang, Yue-Zhu; Li, Yu-Ping; Yang, Dao-Wu; Duan, Feng; Cao, Hong-Bin

    2013-07-01

    The catalysts of Fe/AC, Cu/AC and Fe-Cu/AC with active carbon as support were prepared by a wet impregnation method, and were characterized using X-ray diffraction (XRD), nitrogen adsorption and X-ray photoelectron spectroscopy (XPS) measurements; the catalytic heterogeneous-Fenton processes of phenol degradation with these catalysts were also investigated, and the degradation mechanism was discussed with analysis of intermediate products and electron spin resonance (ESR) measurement. The results showed that the active component states varied in different catalysts; CuO was the main state of Cu in Cu/AC and Fe exhibited various valence states in Fe/AC. The degradation rate of phenol with Fe/AC, Cu/AC and Fe-Cu/AC as catalyst in the initial 60 min reached 96.7%, 77.5% and 99%, respectively; the dissolution of a little active-component metal was found in Cu/AC and Fe-Cu/AC, but little Fe in Fe/AC was dissolved; the degradation of phenol was performed by heterogeneous Fe/AC instead of dissolved Fe, and the degradation rate was above 93% after Fe/AC was used for three cycle runs, showing a stable catalytic activity. Under the optimum conditions of pH = 3, T = 303 K, and 4.38 mmol x L(-1) H2O2, the removal of phenol and TOC in the Fe/AC-catalytic Fenton process could reach 97% and 53%, respectively, while little phenol was degraded without catalyst. The ESR results indicated that hydroxyl radical was produced in the catalytic decomposition of H2O2 with Fe/AC as catalyst, demonstrating that the degradation of phenol mainly followed an oxidation pathway of hydroxyl radical; intermediates such as hydroquinone, p-benzenequinone and catechol were obtained, and the results showed thatortho- and para-substitution reaction by hydroxyl might be the main mechanism of phenol oxidation. PMID:24027996

  17. Microwave-assisted Fenton-like decolorization of methyl orange solution using chromium compounds

    Institute of Scientific and Technical Information of China (English)

    LIU Zuo-hua; TAO Chang-yuan; DU Jun; SUN Da-gui; LI Bai-zhan

    2008-01-01

    Azo dyes discharged in the environment are persistent organic pollutants (POPs), which are very difficult to remove. We developed a microwave-assisted Fenton-like process to degrade methyl orange (MO), an azo dye, with hydrogen peroxide (H2O2) catalyzed by chromium compounds coexisting with MO in the solution. Comparison between the Cr(III)-H2O2 and Cr(VI)-H2O2 systems shows that Cr(VI) has a stronger and more stable catalytical activity than Cr(III), and Cr(III) is more susceptible to a change in the acidity or alkalinity of the reaction system. With a Cr(VI) concentration of 10 mmol L-1 or a Cr(III) concentration of 12 mmol L-1 in the solution under the microwave irradiation of a power larger than 300 W for 3 min, 10 mmol L-1 H2O2 can degrade more than 95% of 1 000 mg L-1 methyl orange; when the microwave power is increased to 700 W, the same amount of H2O2 can degrade all methyl orange in the solution with the same amount of Cr(VI) catalyst. Ultraviolet-visible spectrography indicates the cleavage of the azo bond in methyl orange after treatment, suggesting the potential of this Fenton-like process to degrade azo dye POPs. Reusing waste chromium compounds coexisting with dyestuff in wastewater to catalyze the degradation of azo dyes could be a cost-effective technique for azo dyes and chromate manufacturers and/or users to treat their wastewater and prevent POPs from endangering the environment. This is of particular importance to controlling the water quality of the Three Gorges Reservoir.

  18. Use of Both Anode and Cathode Reactions in Wastewater Treatment

    Science.gov (United States)

    Brillas, Enric; Sirés, Ignasi; Cabot, Pere LluíS.

    Here, we describe the fundamentals, laboratory experiments, and environmental applications of indirect electrooxidation methods based on H2O2 electrogeneration such as electro-Fenton, photoelectro-Fenton and peroxicoagulation for the treatment of acidic wastewaters containing toxic and recalcitrant organics. These methods are electrochemical advanced oxidation processes that can be used in divided and undivided electrolytic cells in which pollutants are oxidized by hydroxyl radical (•OH) produced from anode and/or cathode reactions. H2O2 is generated from the two-electron reduction of O2 at reticulated vitreous carbon, graphite, carbon-felt, and O2-diffusion cathodes. The most usual method is electro-Fenton where Fe2 + added to the wastewater reacts with electrogenerated H2O2 to yield •OH and Fe3 + from Fenton's reaction. An advantage of this technique is that Fe2 + is continuously regenerated from cathodic reduction of Fe3 +. The characteristics of different electro-Fenton systems where pollutants are simultaneously destroyed by •OH formed in the medium from Fenton's reaction and at the anode surface from water oxidation are explained. The effect of the anode [Pt or boron-doped diamond (BDD)] and cathode (carbon-felt or O2-diffusion) on the degradation rate of persistent industrial by-products, herbicides, pharmaceuticals, dyes, etc. is examined. Initial pollutants react much more rapidly with •OH formed in the medium and their degradation sequences are discussed from aromatic intermediates and finally short aliphatic acids are detected. The synergetic positive catalytic effect of Cu2 + on the electro-Fenton process is evidenced. The photoelectro-Fenton method involves the irradiation of the wastewater with UVA light that rapidly photodecomposes complexes of Fe3 + with final carboxylic acids enhancing total decontamination. The peroxicoagulation method uses a sacrificial Fe anode that is continuously oxidized to Fe2 + and organics are either mineralized

  19. Superiority of solar Fenton oxidation over TiO2 photocatalysis for the degradation of trimethoprim in secondary treated effluents.

    Science.gov (United States)

    Michael, I; Hapeshi, E; Michael, C; Fatta-Kassinos, D

    2013-01-01

    The overall aim of this work was to examine the degradation of trimethoprim (TMP), which is an antibacterial agent, during the application of two advanced oxidation process (AOP) systems in secondary treated domestic effluents. The homogeneous solar Fenton process (hv/Fe(2+)/H2O2) and heterogeneous photocatalysis with titanium dioxide (TiO2) suspensions were tested. It was found that the degradation of TMP depends on several parameters such as the amount of iron salt and H2O2, concentration of TiO2, pH of solution, solar irradiation, temperature and initial substrate concentration. The optimum dosages of Fe(2+) and H2O2 for homogeneous ([Fe(2+)] = 5 mg L(-1), [H2O2] = 3.062 mmol L(-1)) and TiO2 ([TiO2] = 3 g L(-1)) for heterogeneous photocatalysis were established. The study indicated that the degradation of TMP during the solar Fenton process is described by a pseudo-first-order reaction and the substrate degradation during the heterogeneous photocatalysis by the Langmuir-Hinshelwood kinetics. The toxicity of the treated samples was evaluated using a Daphnia magna bioassay and was finally decreased by both processes. The results indicated that solar Fenton is more effective than the solar TiO2 process, yielding complete degradation of the examined substrate within 30 min of illumination and dissolved organic carbon (DOC) reduction of about 44% whereas the respective values for the TiO2 process were ∼70% degradation of TMP within 120 min of treatment and 13% DOC removal. PMID:23508150

  20. Effect of Fenton treatment on the aquatic toxicity of bisphenol A in different water matrices

    DEFF Research Database (Denmark)

    Arslan-Alaton, Idil; Aytac, Ece; Kusk, Kresten Ole

    2014-01-01

    incomplete, speaking for the accumulation of refractory degradation products. The presence of chloride and/or natural organic matter influenced H2O2 consumption rates and the treatment performance of the Fenton's reagent as well. The sensitivity of the selected test organisms for BPA and its Fenton treatment...

  1. Chelate-modified polymers for atmospheric gas chromatography

    Science.gov (United States)

    Christensen, W. W.; Mayer, L. A.; Woeller, F. H. (Inventor)

    1980-01-01

    Chromatographic materials were developed to serve as the stationary phase of columns used in the separation of atmospheric gases. These materials consist of a crosslinked porous polymer matrix, e.g., a divinylbenzene polymer, into which has been embedded an inorganic complexed ion such as N,N'-ethylene-bis-(acetylacetoniminato)-cobalt (2). Organic nitrogenous bases, such as pyridine, may be incorporated into the chelate polymer complexes to increase their chromatographic utility. With such materials, the process of gas chromatography is greatly simplified, especially in terms of time and quantity of material needed for a gas separation.

  2. Heterogeneous UV/Fenton catalytic degradation of wastewater containing phenol with Fe-Cu-Mn-Y catalyst

    Institute of Scientific and Technical Information of China (English)

    郑展望; 雷乐成; 徐生娟; 岑沛霖

    2004-01-01

    The heterogeneous UV/Fenton process with the appropriate amount of Fe-Mn-Cu-Y as catalyst was developed and various operation conditions for the degradation of phenol were evaluated. The results indicated that by using the heterogeneous UV/Fenton process, the CODer removal rate reached almost 100% for wastewater containing phenol. Compared with the homogeneous process, the developed catalyst could be used at wider pH range in the UV/Fenton process. Comparison of various heterogeneous process showed that heterogeneous UV/Fenton process was best. The heterogeneous UV/Fenton process with Fe-Mn-Cu-Y catalyst is highly efficient in degrading various organic pollutants.

  3. Heterogeneous UV/Fenton catalytic degradation of wastewater containing phenol with Fe-Cu-Mn-Y catalyst

    Institute of Scientific and Technical Information of China (English)

    郑展望; 雷乐成; 徐生娟; 岑沛霖

    2004-01-01

    The heterogeneous UV/Fenton process with the appropriate amount of Fe-Mn-Cu-Y as catalyst was developed and various operation conditions for the degradation of phenol were evaluated. The results indicated that by using the heterogeneous UV/Fenton process, the CODcr removal rate reached almost 100% for wastewater containing phenol. Compared with the homogeneous process, the developed catalyst could be used at wider pH range in the UV/Fenton process. Comparison of various heterogeneous process showed that heterogeneous UV/Fenton process was best. The heterogeneous UV/Fenton process with Fe-Mn-Cu-Y catalyst is highly efficient in degrading various organic pollutants.

  4. Alternate switching between microbial fuel cell and microbial electrolysis cell operation as a new method to control H2O2 level in Bioelectro-Fenton system

    Science.gov (United States)

    Zhang, Yifeng; Wang, Yong; Angelidaki, Irini

    2015-09-01

    Sustainable H2O2 supply and cost-effective elimination of residual H2O2 are two key challenges associated with the successful application of Fenton reaction for contaminant removal. In this study, an innovative Bioelectro-Fenton system capable of alternate switching between microbial electrolysis cell (MEC) and microbial fuel cell (MFC) mode of operation was developed to meet the challenges. In the MEC mode, a bioelectrochemical system (BES) produces H2O2 which reacts with Fenton's reagent (Fe II) to form hydroxyradical. The unused H2O2 (residual H2O2) is removed as electron acceptor by switching the system to MFC mode of operation. Complete decolorization and mineralization of 50 mg L-1 methylene blue (MB) was achieved in the MEC mode with apparent first order rate constants of 0.43 and 0.22 h-1, respectively. After switching to the MFC mode, residual H2O2 of 180 mg L-1 was removed at a removal rate of 4.61 mg L-1 h-1 while generating a maximum current density of 0.49 A m-2. The MB degradation and residual H2O2 removal were affected by external resistance, cathode pH and initial MB concentration. Furthermore, the system performance was enhanced under stack operation. This study provides a proof-in-concept new system for efficient and cost-effective H2O2 control and recalcitrant pollutants removal.

  5. Application of solar photo-Fenton at circumneutral pH to nanofiltration concentrates for removal of pharmaceuticals in MWTP effluents.

    Science.gov (United States)

    Miralles-Cuevas, S; Oller, I; Pérez, J A Sánchez; Malato, S

    2015-01-01

    In view of the inefficient elimination of micro-pollutants by today's conventional biological treatments and new legislation requiring elimination of at least 80 % of their concentration, the application of an advanced tertiary treatment must be studied. A good option would be advanced oxidation processes (AOPs), which have very often been combined with physicochemical pre-treatSments to increase efficiency or reduce operating costs. This study focused on the combination of membrane nanofiltration and solar photo-Fenton for the main purpose of removing five pharmaceuticals (sulfamethoxazole, ibuprofen, ofloxacin, carbamazepine and flumequine) from real MWTP effluents under realistic conditions (μg L(-1)). This research also included tests performed with modified photo-Fenton using a low iron concentration at circumneutral pH and a low hydrogen peroxide dose, in an attempt to reduce major treatment costs. Over 80 % of dissolved organic carbon, chemical oxygen demand and turbidity were also retained during nanofiltration, making pharmaceutical removal less efficient in terms of concentrate treatment time than direct treatment, i.e. the concentrate illumination time was around 150 min while direct treatment was around 40 min. Nevertheless, it should be highlighted that, although no savings in installation costs was observed for the combined system (nanofiltration/solar photo-Fenton), the reaction rate improved and so, there was a savings in reagent costs (mainly hydrogen peroxide and sulfuric acid). PMID:24756680

  6. Heterogeneous Fenton-like discoloration of methyl orange using Fe3O4/MWCNTs as catalyst: process optimization by response surface methodology

    Science.gov (United States)

    Xu, Huan-Yan; Shi, Tian-Nuo; Zhao, Hang; Jin, Li-Guo; Wang, Feng-Chun; Wang, Chun-Yan; Qi, Shu-Yan

    2016-03-01

    Fe3O4/MWCNTs nanocomposites were prepared by chemical oxidation coprecipitation method and developed as highly efficient heterogeneous Fenton-like catalyst. XRD results revealed that Fe3O4 nanoparticles deposited onto MWCNTs surface remained the inverse spinel crystal structure of cubic Fe3O4 phase. The FTIR characteristic peaks of MWCNTs weakened or disappeared due to the anchor of Fe3O4 nanoparticles and Fe-O peak at 570 cm-1 was indicative of the formation of Fe3O4. TEM observation revealed that Fe3O4 nanoparticles were tightly anchored by MWCNTs. The Fenton-like catalytic activity of Fe3O4/MWCNTs nanocomposites for the discoloration of methyl orange (MO) was much higher than that of Fe3O4 nanoparticles. The process optimization of this heterogeneous Fenton-like system was implemented by response surface methodology (RSM). The optimum conditions for MO discoloration were determined to be of 12.3 mmol/L H2O2 concentration, 2.9 g/L catalyst dosage, solution pH 2.7 and 39.3 min reaction time, with the maximum predicted value for MO discoloration ratio of 101.85%. The corresponding experimental value under the identical conditions was obtained as 99.86%, which was very close to the predicted one with the absolute deviation of 1.99%.

  7. Treatment of 2-phenylamino-3-methyl-6-di-n-butylaminofluoran production effluent by combination of biological treatments and Fenton's oxidation

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    High strength refractory organic stream is produced during the production of 2-phenylamino-3-methyl-6-di-n-butylaminofluoran(One Dye Black 2, abbr. ODB 2), a novel heat-sensitive material with a promising market. In this study, a combination of acidificationprecipitation, primary biological treatment, Fenton's oxidation and another biological treatment was successfully used for the removal of COD from 18000-25000 mg/L to below 200 mg/L from the ODB 2 production wastewater in a pilot experiment. A COD removal of 70%-80% was achieved by acidification-precipitation under a pH of 2.5-3.0. The first step biodegradation permitted an average COD removal of 70% under an hydraulic residence time (HRT) of 30 h. By batch tests, the optimum conditions of Fenton's oxidation were acquired as: Fe2+ dose 6.0 mmol/L; H2O2 dose 3000 mg/L; and reaction time 6 h. The second step biological treatment could ensure an effluent COD below 200 mg/L under an HRT of 10 h following the Fenton's treatment.

  8. Degradation of ion spent resin using the Fenton's reagent; Degradacao da resina de troca ionica utilizando o reagente de Fenton

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Leandro Goulart de

    2013-07-01

    The most common method for spent radioactive ion exchange resin treatment is its immobilization in cement, which reduces the radionuclides release into the environment. Although this method is efficient, it increases considerably the final volume of the waste due to the low incorporation capacity. The objective of this work was to develop a degradation method of spent resins arising from the nuclear research reactor located at the Nuclear and Energy Research Institute (IPEN-CNEN/SP), using an Advanced Oxidation Process (AOP) with Fenton's reagents. This method would allow a higher incorporation in cement. Three different resins were evaluated: cationic, anionic and a mixture of both resins. The reactions were conducted varying the catalyst concentration (25, 50, 100 and 150 mM), the volume of hydrogen peroxide (320 to 460 mL), and three different temperatures, 50, 60 and 70 deg C. Degradation of about 98% was achieved using a 50 mM catalyst solution and 330 mL of hydrogen peroxide solution. The most efficient temperature was 60 deg C. (author)

  9. Removal of refractory organics in nanofiltration concentrates of municipal solid waste leachate treatment plants by combined Fenton oxidative-coagulation with photo--Fenton processes.

    Science.gov (United States)

    Li, Jiuyi; Zhao, Lei; Qin, Lele; Tian, Xiujun; Wang, Aimin; Zhou, Yanmei; Meng, Liao; Chen, Yong

    2016-03-01

    Removal of the refractory organic matters in leachate brines generated from nanofiltration unit in two full-scale municipal solid waste landfill leachate treatment plants was investigated by Fenton oxidative-coagulation and ultraviolet photo - Fenton processes in this study. Fenton oxidative-coagulation was performed under the condition of an initial pH of 5.0 and low H2O2/Fe(2+) ratios. After precipitate separation, the remaining organic constituents were further oxidized by photo - Fenton process. For both leachate brines with varying pollution strength, more than 90% COD and TOC reductions were achieved at H2O2/Fe(2+) dosages of 35 mM/8 mM and 90 mM/10 mM, respectively. The effluent COD ranged 120-160 mg/L under the optimal operating conditions, and the biodegradability was increased significantly. Fenton oxidative-coagulation was demonstrated to contribute nearly 70% overall removal of organic matters. In the combined processes, the efficiency of hydrogen peroxide varied from 216 to 228%, which may significantly reduce the operating cost of conventional Fenton method. Six phthalic acid esters and thirteen polycyclic aromatic hydrocarbons were found in leachate brines, and, on the average, around 80% phthalic acid esters and 90% polycyclic aromatic hydrocarbons were removed by the combined treatments. PMID:26741550

  10. Sistema de injeção em fluxo espectrofotométrico para monitorar peróxido de hidrogênio em processo de fotodegradação por reação foto-Fenton Flow injection spectrophotometric system for hydrogen peroxide monitoring in photo-Fenton degradation processes

    Directory of Open Access Journals (Sweden)

    Mirela C. Oliveira

    2001-04-01

    Full Text Available A flow injection spectrophotometric system was projected for monitoring hydrogen peroxide during photodegradation of organic contaminants in photo-Fenton processes (Fe2+/H2O2/UV. Sample is injected manually in a carrier stream and then receives by confluence a 0.1 mol L-1 NH4VO3 solution in 0.5 mol L-1 H2SO4 medium. The product formed shows absorption at 446 nm which is recorded as a peak with height proportional to H2O2 concentration. The performance of the proposed system was evaluated by monitoring the consumption of H2O2 during the photodegradation of dichloroacetic acid solution by foto-Fenton reaction.

  11. Involutin is an Fe3+ reductant secreted by the ectomycorrhizal fungus Paxillus involutus during Fenton-based decomposition of organic matter.

    Science.gov (United States)

    Shah, Firoz; Schwenk, Daniel; Nicolás, César; Persson, Per; Hoffmeister, Dirk; Tunlid, Anders

    2015-12-01

    Ectomycorrhizal fungi play a key role in mobilizing nutrients embedded in recalcitrant organic matter complexes, thereby increasing nutrient accessibility to the host plant. Recent studies have shown that during the assimilation of nutrients, the ectomycorrhizal fungus Paxillus involutus decomposes organic matter using an oxidative mechanism involving Fenton chemistry (Fe(2+) + H2O2 + H(+) → Fe(3+) + ˙OH + H2O), similar to that of brown rot wood-decaying fungi. In such fungi, secreted metabolites are one of the components that drive one-electron reductions of Fe(3+) and O2, generating Fenton chemistry reagents. Here we investigated whether such a mechanism is also implemented by P. involutus during organic matter decomposition. Activity-guided purification was performed to isolate the Fe(3+)-reducing principle secreted by P. involutus during growth on a maize compost extract. The Fe(3+)-reducing activity correlated with the presence of one compound. Mass spectrometry and nuclear magnetic resonance (NMR) identified this compound as the diarylcyclopentenone involutin. A major part of the involutin produced by P. involutus during organic matter decomposition was secreted into the medium, and the metabolite was not detected when the fungus was grown on a mineral nutrient medium. We also demonstrated that in the presence of H2O2, involutin has the capacity to drive an in vitro Fenton reaction via Fe(3+) reduction. Our results show that the mechanism for the reduction of Fe(3+) and the generation of hydroxyl radicals via Fenton chemistry by ectomycorrhizal fungi during organic matter decomposition is similar to that employed by the evolutionarily related brown rot saprotrophs during wood decay. PMID:26431968

  12. Electro-Fenton法的影响因素及研究进展%The Influential Factors of Electro-Fenton Method and Research Progress

    Institute of Scientific and Technical Information of China (English)

    杨新涛; 马如意; 王倩; 吴玉凯

    2014-01-01

    Electro-Fenton法是一种新型的电催化氧化技术,具有“环境友好”的特点,是一种高级氧化技术(AOPs)。结合国内外Electro-Fenton法的研究近况,阐述Fenton法的作用机理及主要影响因素,主要受pH值、O2流量、温度、电流密度、Fe2+离子浓度、电极间距离、电解质及电极材料等因素影响,结合具体的废水对主要反应参数进行总结,分析作用机理。对Electro-Fenton法的研究发展趋势提出了一些观点。%Electro-Fenton method is a new type of electric catalytic ox idation technology, has the characteristics of"environmentally friendly", is a kind of Advanced Oxidation Processes (AOPs). It was combined with the research status of Electro-Fenton method in recent years, expounds the mechanism of Electro-Fenton method and main influence factors. pH, O2 flow rate, temperature, current density, ferrous ion concentration, the distance between the electrodes, electrolyte and electrode materials are the main influence factors. Combined with specific wastewater to summarize main reaction parameters, the mechanism was analyzed. Some views of the trend of research and development of the Electro-Fenton method were put forward.

  13. Electrogeneration of hydrogen peroxide for electro-Fenton via oxygen reduction using polyacrylonitrile-based carbon fiber brush cathode

    International Nuclear Information System (INIS)

    Polyacrylonitrile-based carbon fiber brush (PAN-CFB) cathode was used to electrogenerate hydrogen peroxide (H2O2) via oxygen reduction reaction (ORR) and to degrade phenol in electro-Fenton system. Due to inherent N-containing structure, PAN-CFB cathode generated H2O2 efficiently (current efficiency at 300 mA >90%), showing high selectivity toward 2-electron ORR independent of medium (H2SO4, Na2SO4 or NaOH). Moreover, the influence of parameters such as applied current, cathodic potential, electrolyte concentration and volume as well as electrode distance on H2O2 electrogeneration was investigated in detail. Finally, the degradation of phenol was evaluated by ultraviolet (UV) spectra analysis and COD measurement. 86.2% of COD removal was achieved under the optimum conditions (pH 3, I = 300 mA, 0.3 mmol L−1 Fe2+) after 240 min, meaning the almost complete degradation of phenol via electro-Fenton process using PAN-CFB cathode

  14. Optimization of Fenton-based treatment of petroleum refinery wastewater with scrap iron using response surface methodology

    Science.gov (United States)

    Saber, Ali; Hasheminejad, Hasti; Taebi, Amir; Ghaffari, Ghasem

    2014-09-01

    The ever-increasing number and production capacity of petroleum refineries in recent years have intensified the need for developing an effective and practical method for treating their wastewaters. In this study, the application of Fenton process with scrap iron powder was investigated for the treatment of a bio-refractory petroleum refinery effluent. Response surface methodology was employed with a cubic IV optimal design to optimize the process using chemical oxygen demand (COD) removal as the target response. H2O2/COD, and H2O2/Fe mass ratios as well as pH were considered as the relevant parameters. A COD removal of more than 83 % was achieved under optimal conditions (H2O2/COD 10.03, H2O2/Fe 2.66 and pH 3.0) within 90 min. Kinetics studies were conducted to investigate the effect of reaction time on COD removal. In addition, the role of post-coagulation on COD removal under optimal conditions was investigated and it was found that 37 % of COD removal occurred due to coagulation, indicating its high potential in the Fenton process.

  15. Carbon isotope effects associated with Fenton-like degradation of toluene: Potential for differentiation of abiotic and biotic degradation

    International Nuclear Information System (INIS)

    Hydrogen peroxide (H2O2)-mediated oxygenation to enhance subsurface aerobic biodegradation is a frequently employed remediation technique. However, it may be unclear whether observed organic contaminant mass loss is caused by biodegradation or chemical oxidation via hydroxyl radicals generated during catalyzed Fenton-like reactions. Compound-specific carbon isotope analysis has the potential to discriminate between these processes. Here we report laboratory experiments demonstrating no significant carbon isotope fractionation during Fenton-like hydroxyl radical oxidation of toluene. This implies that observation of significant isotopic fractionation of toluene at a site undergoing H2O2-mediated remediation would provide direct evidence of biodegradation. We applied this approach at a field site that had undergone 27 months of H2O2-mediated subsurface oxygenation. Despite substantial decreases (> 68%) in groundwater toluene concentrations carbon isotope signatures of toluene (δ13Ctol) showed no significant variation (mean = - 27.5 ±0.3 per mille, n = 13) over a range of concentrations from 11.1 to 669.0 mg L-1. Given that aerobic degradation by ring attack has also been shown to result in no significant isotopic fractionation during degradation, at this site we were unable to discern the mechanism of degradation. However, such differentiation is possible at sites where aerobic degradation by methyl group attack results in significant isotopic fractionation

  16. Mineralization of phthalic acid by solar photoelectro-Fenton with a stirred boron-doped diamond/air-diffusion tank reactor: Influence of Fe3+ and Cu2+ catalysts and identification of oxidation products

    International Nuclear Information System (INIS)

    Highlights: • Almost total mineralization of phthalic acid by solar photoelectro-Fenton with Fe3+, Cu2+ and Fe3+–Cu2+ mixtures. • Hydroxyl radical generation from photo-Fenton reaction under solar radiation. • Enhancement of the mineralization rate using Fe3+ and small amounts of Cu2+. • Detection of eleven aromatic intermediates and six short-linear carboxylic acids. • Oxidation of Cu(II)-carboxylate complexes with ·OH and photolysis of Fe(III)-carboxylate species. -- Abstract: Here, the substrate decay and mineralization rate for 100 cm3 of a 2.0 mM phthalic acid solution in 0.10 M Na2SO4 of pH 3.0 have been studied by electro-Fenton (EF) and solar photoelectro-Fenton (SPEF). The electrochemical cell was a stirred tank reactor containing a 3 cm2 boron-doped diamond (BDD) anode and a 3 cm2 air-diffusion cathode that generates H2O2. Cu2+ and/or Fe3+ were added as catalysts with total concentration of 0.50 mM and a constant current density of 33.3 mA cm−2 was applied. In EF with Cu2+ or Fe3+ alone and SPEF with only Cu2+, phthalic acid decayed slowly and poor mineralization was reached because the main oxidant was ·OH produced at the BDD surface from water oxidation. In contrast, the substrate destruction was largely enhanced using SPEF with 0.50 mM Fe3+ since a high quantity of oxidant ·OH was produced in the bulk induced by photo-Fenton reaction. This treatment led to an almost total mineralization by the photolysis of generated Fe(III)-carboxylate complexes. In all cases, the decay of phthalic acid obeyed a pseudo-first-order reaction. The combination of Cu2+ and Fe3+ as catalysts accelerated the mineralization process in SPEF because Cu(II)-carboxylate complexes were also removed with ·OH formed from photo-Fenton reaction. The best SPEF process was found for 0.125 mM Cu2+ + 0.375 mM Fe3+, giving rise to 99% mineralization with 40% current efficiency and 0.294 kWh g−1 TOC energy consumption. Eleven aromatics and six short-linear carboxylic

  17. DI-(2-ETHYLHEXYL PHTHALATE OXIDATIVE DEGRADATION BY FENTON PROCESS IN SYNTHETIC AND REAL PETROCHEMICAL WASTEWATER

    Directory of Open Access Journals (Sweden)

    R. Esmaeli

    2011-09-01

    Full Text Available Di-(2-Ethylhexyl phthalate (DEHP belongs to the class of phthalate esters and is used as an additive in many products including plastics, paints and inks or as a solvent in industrial formulations. The degradation of DEHP in aqueous solution using oxidative Fenton reaction (H2O2/Fe2+ was carried out in this study. It was found that H2O2 concentration, Fe2+ concentration, and pH were the three main factors that could significantly influence the degradation rates of DEHP. The highest degradation percentage (85.6 % of DEHP was observed within 60 min at pH 3 in H2O2/Fe2+ system. The results of our study suggested that the concentration with 90 mg/L H2O2, 5 mg/L Fe2+, and 20 mg/L DEHP in the solution at pH 3 were the optimal conditions. The optimized reaction parameters were preceded for treatment of real wastewater obtained from a petrochemical plant.

  18. Photo-fenton remediation of wastewaters containing agrochemicals

    Directory of Open Access Journals (Sweden)

    Antonio Carlos Silva Costa Teixeira

    2005-06-01

    Full Text Available The photochemical degradation of agrochemicals in aqueous solution by means of advanced oxidation processes (AOPs was studied. The photo-Fenton process was evaluated in terms of the time evolution of dissolved organic carbon (COD and chemical oxygen demand (DOC, their total removals, and increase in biodegradability of treated wastewater. Under the experimental conditions studied, the process showed to be superior to other AOPs, at any Fe(II and H2O2 concentrations. The results pointed towards the use of solar irradiation and low cost commercial application.Neste trabalho, estuda-se a degradação fotoquímica de defensivos agrícolas presentes em efluentes aquosos, por meio de processos oxidativos avançados (POAs. Tais processos são baseados na ação do radical hidroxila (HO•, oxidante poderoso e não seletivo. Em particular, o processo foto-Fenton é avaliado quanto à redução da demanda química de oxigênio (DQO e do teor de carbono orgânico dissolvido (COD, e ao aumento de biodegradabilidade dos efluentes. Os resultados abrem perspectivas para emprego de irradiação solar e aplicação em escala comercial a baixo custo.

  19. Decolorization of C.I. Acid Blue 9 solution by UV/Nano-TiO2, Fenton, Fenton-like, electro-Fenton and electrocoagulation processes: A comparative study

    International Nuclear Information System (INIS)

    This study makes a comparison between UV/Nano-TiO2, Fenton, Fenton-like, electro-Fenton (EF) and electrocoagulation (EC) treatment methods to investigate the removal of C.I. Acid Blue 9 (AB9), which was chosen as the model organic contaminant. Results indicated that the decolorization efficiency was in order of Fenton > EC > UV/Nano-TiO2 > Fenton-like > EF. Desired concentrations of Fe2+ and H2O2 for the abatement of AB9 in the Fenton-based processes were found to be 10-4 M and 2 x 10-3 M, respectively. In the case of UV/Nano-TiO2 process, we have studied the influence of the basic photocatalytic parameters such as the irradiation time, pH of the solution and amount of TiO2 nanoparticles on the photocatalytic decolorization efficiency of AB9. Accordingly, it could be stated that the complete removal of color, after selecting desired operational parameters could be achieved in a relatively short time, about 25 min. Our results also revealed that the most effective decomposition of AB9 was observed with 150 mg/l of TiO2 nanoparticles in acidic condition. The effect of operational parameters including current density, initial pH and time of electrolysis were studied in electrocoagulation process. The results indicated that for a solution of 20 mg/l AB9, almost 98% color were removed, when the pH was about 6, the time of electrolysis was 8 min and the current density was approximately 25 A/m2 in electrocoagulation process

  20. Decolorization of C.I. Acid Blue 9 solution by UV/Nano-TiO{sub 2}, Fenton, Fenton-like, electro-Fenton and electrocoagulation processes: A comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Khataee, A.R. [Water and Wastewater Treatment Research Laboratory, Department of Applied Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz (Iran, Islamic Republic of)], E-mail: a_khataee@tabrizu.ac.ir; Vatanpour, V. [Water and Wastewater Treatment Research Laboratory, Department of Applied Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz (Iran, Islamic Republic of)], E-mail: vahidvatanpoor@yahoo.com; Amani Ghadim, A.R. [Water and Wastewater Treatment Research Laboratory, Department of Applied Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz (Iran, Islamic Republic of)], E-mail: a.r_amani@yahoo.com

    2009-01-30

    This study makes a comparison between UV/Nano-TiO{sub 2}, Fenton, Fenton-like, electro-Fenton (EF) and electrocoagulation (EC) treatment methods to investigate the removal of C.I. Acid Blue 9 (AB9), which was chosen as the model organic contaminant. Results indicated that the decolorization efficiency was in order of Fenton > EC > UV/Nano-TiO{sub 2} > Fenton-like > EF. Desired concentrations of Fe{sup 2+} and H{sub 2}O{sub 2} for the abatement of AB9 in the Fenton-based processes were found to be 10{sup -4} M and 2 x 10{sup -3} M, respectively. In the case of UV/Nano-TiO{sub 2} process, we have studied the influence of the basic photocatalytic parameters such as the irradiation time, pH of the solution and amount of TiO{sub 2} nanoparticles on the photocatalytic decolorization efficiency of AB9. Accordingly, it could be stated that the complete removal of color, after selecting desired operational parameters could be achieved in a relatively short time, about 25 min. Our results also revealed that the most effective decomposition of AB9 was observed with 150 mg/l of TiO{sub 2} nanoparticles in acidic condition. The effect of operational parameters including current density, initial pH and time of electrolysis were studied in electrocoagulation process. The results indicated that for a solution of 20 mg/l AB9, almost 98% color were removed, when the pH was about 6, the time of electrolysis was 8 min and the current density was approximately 25 A/m{sup 2} in electrocoagulation process.

  1. Soil washing in combination with homogeneous Fenton-like oxidation for the removal of 2,4,4'-trichlorodiphenyl from soil contaminated with capacitor oil.

    Science.gov (United States)

    Ma, Xiao-Hong; Zhao, Ling; Lin, Zhi-Rong; Dong, Yuan-Hua

    2016-04-01

    Detoxification by chemical oxidation of polychlorinated biphenyls (PCBs) in contaminated soils is very difficult and inefficient because PCBs typically associate with the solid phase or exist as non-aqueous-phase liquids due to their low solubility and slow desorption rates, and thus, they are difficult to remove from soils by using traditional, water-based elution techniques. Surfactant can enhance washing efficiency of PCBs from contaminated soils. This study used Brij 58, Brij 30, Tween 80, and 2-hydroxypropyl-β-cyclodextrin (HPCD) to solubilize 2,4,4'-trichlorodiphenyl (PCB28) from soil contaminated with capacitor oil into solution. The feasibility of PCB28 oxidation in soil washing wastewater through a Fe(3+)-catalyzed Fenton-like reaction was subsequently examined. Washing with 10 g L(-1) Brij 58 solution showed the highest extraction efficiency (up to 61.5 %) compared with that of the three other surfactants. The total concentration of PCB28 in contaminated soil at 25 °C after 48-h extraction was 286 mg L(-1). In contrast to conditions in which no washing agent was added, addition of the four washing agents decreased the efficiency of PCB28 degradation by the Fenton-like reaction, with the decrease due to addition of 10 g L(-1) Brij 58 solution being the smallest. The optimal concentration of H2O2 for preventing its useless decomposition was found to be 50 mM. The efficiency of PCB28 removal was lower when the initial concentration of PCB28 treated in the Fenton-like reaction was higher. The degradation efficiencies of PCB28 at initial concentrations of 0.1, 10, and 176 mg L(-1) in 10 g L(-1) Brij 58 solution at 25 °C and pH 3.0 and 9 h of reaction using 50 mM H2O2 were 64.1, 42.0, and 34.6 %, respectively. This result indicates that soil washing combined with Fenton-like oxidation may be a practical approach for the remediation of PCB-contaminated soil. PMID:26762933

  2. Élimination des polluants organiques de l'eau par les procédés électrochimiques : procédés électro-Fenton et électro-Fenton modifiés

    OpenAIRE

    Lin, Heng

    2015-01-01

    In this paper, electro-Fenton and sulfate radical-based electro-Fenton-like processes were used to degrade artificial sweeteners and azo dye. The results obtained during the research concern the removal efficiency, the oxidation mechanism, degradation pathway and toxicity evolution of target pollutants.(1) Electro-Fenton process was a effective method for the degradation of ASP in water. The removal and mineralization rate was affected by the Fe2+ concentration and applied current. The absolu...

  3. Degradation of three pesticides used in viticulture by electrogenerated Fenton's reagent

    OpenAIRE

    Oturan, Nihal; A. Oturan, Mehmet

    2005-01-01

    The degradation of three pesticides: Mistel GD (Cymoxanil + Mancozeb + additives), Cuprofix CZ (Cymoxanil + Zineb + CuSO4 + additives) and Lannate 20L (Metomyl + ethanol + other additives) (Fig. 1), used in viticulture and marketed by various companies, was studied by the Electro-Fenton process. The Fenton's reagent, generated in situ by electrochemistry in a catalytic way, leads to the production of hydroxyl radicals which are very powerful oxidizing agents. These radicals react with organic...

  4. Application of Electro-Fenton Technology to Remediation of Polluted Effluents by Self-Sustaining Process

    OpenAIRE

    2014-01-01

    The applicability of electro-Fenton technology to remediation of wastewater contaminated by several organic pollutants such as dyes and polycyclic aromatic hydrocarbons has been evaluated using iron-enriched zeolite as heterogeneous catalyst. The electro-Fenton technology is an advanced oxidation process that is efficient for the degradation of organic pollutants, but it suffers from the high operating costs due to the need for power investment. For this reason, in this study microbial fuel c...

  5. BİR İLERİ OKSİDASYON PROSESİ : FENTON PROSES

    OpenAIRE

    Engin GÜRTEKİN; Nusret ŞEKERDAĞ

    2008-01-01

    Biological wastewater treatment is not effective treatment method if raw wastewater contains toxic and refractory organics. Advanced oxidation processes are applied before or after biological treatment for the detoxification and reclamation of this kind of wastewaters. The advanced oxidation processes are based on the formation of powerful hydroxyl radicals. Among advanced oxidation processes Fenton process is one of the most promising methods. Because application of Fenton process is simple ...

  6. Peer Review of the Hot Dry Rock Project at Fenton Hill, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    None

    1998-12-01

    This report briefly describes the history of the hot dry rock experiment project conducted by the U.S. Department of Energy and Los Alamos National Laboratory at Fenton Hill, New Mexico, from about 1971 through 1995. The authors identify the primary lessons learned and techniques developed during the course of the Fenton Hill project, and summarize the extent to which these technologies have been transferred to the U.S. geothermal industry.

  7. Combined zero-valent iron and fenton processes for the treatment of Brazilian TNT industry wastewater

    International Nuclear Information System (INIS)

    The environmental impact caused by the production of explosives made from nitroaromatic compounds such as 2,4,6-trinitrotoluene (TNT) is currently a major concern, mainly due to their toxic nature, a fact that makes these compounds highly harmful. This work evaluated a continual system treatment reactor (CSTR) consisting of column zero-valent iron and a system to promote a fenton reaction in order to create possible definitive routines for treating effluents originating from the TNT production process. The spectrophotometric results demonstrated that this combination of processes was highly efficient in promoting the removal of all the absorbed species at 290 nm and the visible region of the specter. The results also revealed that the combination of treatments was significantly efficient in terms of correcting the effluent's main parameters of relevance, mainly COD (95.5% reduction) and TNT concentration, whose total was converted into nitrous and phenolic compounds and, additionally, the acute toxicity was also significantly reduced (95%). These results indicate that the strategy can serve as an efficient option for effluent treatment, for release into the receiving body, or eventually for use as industrial reuse water.

  8. Combined Chemical Activation and Fenton Degradation to Convert Waste Polyethylene into High-Value Fine Chemicals.

    Science.gov (United States)

    Chow, Cheuk-Fai; Wong, Wing-Leung; Ho, Keith Yat-Fung; Chan, Chung-Sum; Gong, Cheng-Bin

    2016-07-01

    Plastic waste is a valuable organic resource. However, proper technologies to recover usable materials from plastic are still very rare. Although the conversion/cracking/degradation of certain plastics into chemicals has drawn much attention, effective and selective cracking of the major waste plastic polyethylene is extremely difficult, with degradation of C-C/C-H bonds identified as the bottleneck. Pyrolysis, for example, is a nonselective degradation method used to crack plastics, but it requires a very high energy input. To solve the current plastic pollution crisis, more effective technologies are needed for converting plastic waste into useful substances that can be fed into the energy cycle or used to produce fine chemicals for industry. In this study, we demonstrate a new and effective chemical approach by using the Fenton reaction to convert polyethylene plastic waste into carboxylic acids under ambient conditions. Understanding the fundamentals of this new chemical process provides a possible protocol to solve global plastic-waste problems. PMID:27168079

  9. Degradation of n-butyl xanthate using fly ash as heterogeneous Fenton-like catalyst

    Institute of Scientific and Technical Information of China (English)

    陈绍华; 杜冬云

    2014-01-01

    Heterogeneous Fenton-like process using fly ash as a catalyst was studied to degrade n-butyl xanthate form aqueous solution. The different reaction parameters on the degradation efficiency of the process were investigated. The fly ash/H2O2 catalyst possesses a high oxidation activity for n-butyl xanthate degradation in aqueous solution. It is found that both the dosage of catalyst and initial solution pH significantly affect the n-butyl xanthate conversion efficient. The results indicate that by using 1.176 mmol/L H2O2 and 1.0 g/L fly ash catalyst with mass fraction of 4.14%Fe(III) oxide at pH 3.0, almost 96.90%n-butyl xanthate conversion and over 96.66%COD removal can be achieved within 120 min with heterogeneous catalysis by fly ash. CS2 as an intermediate of n-butyl xanthate oxidation. Finally, it is demonstrated that the fly ash/H2O2 catalytic oxidation process can be an efficient method for the treatment of n-butyl xanthate containing wastewater.

  10. Modified Fe3O4- hydroxyapatite nanocomposites as heterogeneous catalysts in three UV, Vis and Fenton like degradation systems

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Photocatalytic degradation of dye by Ag modified HAP under visible light. • Study of Fenton like degradation of dye by transition metal ions modified HAP. • Comparison of catalytic systems according to Langmuir-Hinshelwood kinetic expression. - Abstract: The magnetite-hydroxyapatite (M-HAP) nanocomposites were prepared by a chemical co- precipitation procedure and characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and diffuse reflectance spectra (DRS). The ability of the synthesized catalyst for photocatalytic degradation of Acid Blue 25 (AB25), as an organic dye, under UV irradiation was studied. The catalyst was modified employing transition metals (Mn, Fe, Co, Ni, Cu and Zn) trying to improve the catalytic performance of HAP in absence of UV irradiation and in the presence of hydrogen peroxide i.e. a Fenton like reaction. The best results obtained for Cu and Co modified M-HAPs and the effect of operational parameters such pH, amount of catalyst and hydrogen peroxide concentration was studied. In order to investigate the performance of HAP based photocatalyst in visible light region, M-HAP was modified with silver ions. At the end, Langmuir-Hinshelwood kinetic expression used to evaluate and compare the catalytic systems. The strongest degradation activity was observed for Ag-M-HAP/Vis system because of Ag3PO4 formation. Apparent reaction rate constant (Kapp) by Ag-M-HAP/Vis was 63, 36 and 19 times faster than Cu-M-HAP(II)/H2O2, Co-M-HAP(II)/H2O2 and M-HAP (I)/UV systems, respectively

  11. Toxicity assessment of tannery effluent treated by an optimized photo-Fenton process.

    Science.gov (United States)

    Borba, Fernando Henrique; Módenes, Aparecido Nivaldo; Espinoza-Quiñones, Fernando Rodolfo; Manenti, Diego Ricieri; Bergamasco, Rosangela; Mora, Nora Diaz

    2013-01-01

    In this work, an optimized photo-Fenton process was applied to remove pollutants from tannery industrial effluent (TIE) with its final toxicity level being assessed by a lettuce-seed-based bioassay test. A full 33 factorial design was applied for the optimization of long-term photo-Fenton experiments. The oPtimum conditions of the photo-Fenton process were attained at concentration values of 0.3 g Fe(2+) L(-1) and 20 g H2O2 L(-1) and pH3, for 120 min UV irradiation time. Reactor operating parameter (ROP) effects on the removal of chemical oxygen demand, colour, turbidity, total suspended solids and total volatile solids were evaluated, suggesting that a broad range of ROP values are also suitable to give results very near to those of the photo-Fenton experiments under optimal conditions. Based on the low calculated median lethal dose (LD50) values from a lettuce-seed-based bioassay test, we suggest that recalcitrant substances are present in treated TIE samples. A possible cause of the high toxicity level could partly be attributed to the nitrate concentration, which was not completely abated by the photo-Fenton process. Apart from this, the photo-Fenton process can be used as a part of an industrial effluent treatment system in order to abate high organic pollutant loads. PMID:23837315

  12. EPR studies on the kinetics of the α-hydroxyethyl radical generated by Fenton-like chemistry

    Science.gov (United States)

    Schubert, Erik; Hett, Tobias; Schiemann, Olav; NejatyJahromy, Yaser

    2016-04-01

    Flow systems, either stopped or continuous, have long been at the core of kinetic studies of chemical reactions. Such flow systems need to be coupled with appropriate spectroscopic or otherwise techniques for the detection of the chemical species studied. If paramagnetic species are formed or consumed during the investigated reaction, electron paramagnetic resonance (EPR) with its nanomolar sensitivity can be the spectroscopic method of choice. However, not much literature is available on the application of EPR to quantitatively study kinetics of chemical reactions in the liquid state. Herein, we report the characterisation of the commercially available mixing resonator ER 4117 MX from BRUKER using the TEMPO-dithionite reaction as a standard. Furthermore, this setup was used to study the kinetics of the Fenton-like system of TiCl3/H2O2 and ethanol forming the α-hydroxyethyl radical. Potential contributions of reactions with O2, H2O2, Ti3+/4+, and self-recombination in the decay of the α-hydroxyethyl radical were investigated and the bimolecular decay was shown to be the dominant decay pathway, with a decay rate constant of 6.6 ×108 M-1 s-1. This study shows the effectiveness and capabilities of EPR as a direct, sensitive and in-situ method in kinetic studies.

  13. Study on Treatability of Real Textile Wastewater by Electrochemically Generated  Fenton Reagent using Graphite Felt Cathode

    OpenAIRE

    Akbar Eslami; Mohammad Reza Massoudinejad; Farshid Ghanbari; Mahsa Moradi

    2012-01-01

    Background and Objectives: Electro-Fenton process has been widely applied for dye removal from aqueous solution lately. Fenton's reagent is formed in the electrolysis medium through the simultaneous electrochemical reduction of O2 and Fe3+ to H2O2 and Fe2+ respectively on the cathode surface. In this paper, COD reduction potential and decolorization of real textile wastewater were evaluated by electrochemically generated Fenton reagent process. This wastewater mainly contains non-biodegradabl...

  14. Decolorization of Diazo Dye Ponceau S by Fenton Process

    International Nuclear Information System (INIS)

    An attempt has been taken to decolorize and mineralize Ponceau S (PS), a diazo dye, in aqueous solution by Fenton process. Effects of solution pH, concentrations of H/sub 2/O/sub 2/, Fe(II) and PS on the decolorization of PS have also been studied through batch experiments. About 90percentage decolorization was found under the optimal conditions (PS): (H/sub 2/O/sub 2/): (Fe(II)) = 1:12:2 and (H/sub 2/O/sub 2/)/(Fe(II)) = 6 at pH 2.85 in 40 minutes. The overall results revealed that mineralization was rather slower as compared with the decolorization. (author)

  15. Heterogeneous photo-Fenton decolorization of Orange II over Al-pillared Fe-smectite: Response surface approach, degradation pathway, and toxicity evaluation

    International Nuclear Information System (INIS)

    Highlights: • Al-pillared Fe-smectite was synthesized and used as the photo-Fenton catalyst. • Response surface methodology was used to study the effects of reaction parameters. • The main intermediate products were identified by GC–MS technique. • A possible degradation pathway of Orange II was proposed. • All the generated products of Orange II were less toxic than the original dye. - Abstract: A ferric smectite clay material was synthesized and further intercalated with Al2O3 pillars for the first time with the aim of evaluating its ability to be used as heterogeneous catalyst for the photo-Fenton decolorization of azo dye Orange II. UV irradiation was found to enhance the activity of the catalyst in the heterogeneous photo-Fenton process. Catalyst loading of 0.5 g/L and hydrogen peroxide concentration of 13.5 mM yielded a remarkable color removal, accompanied by excellent catalyst stability. The decolorization of Orange II followed the pseudo-first-order kinetics for initial dye concentrations from 20 to 160 mg/L. The central composite design (CCD) based on the response surface methodology (RSM) was applied to evaluate the effects of several operating parameters, namely initial pH, catalyst loading and hydrogen peroxide concentration, on the decolorization efficiency. The RSM model was derived and the response surface plots were developed based on the results. Moreover, the main intermediate products were separated and identified using gas chromatography–mass spectrometry (GC–MS) and a possible degradation pathway was proposed accordingly. The acute toxicity experiments illustrated that the Daphniamagna immobilization rate continuously decreased during 150 min reaction, indicating that the effluent was suitable for sequential biological treatment

  16. Heterogeneous photo-Fenton decolorization of Orange II over Al-pillared Fe-smectite: Response surface approach, degradation pathway, and toxicity evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Li, Huiyuan; Li, Yanli [Department of Environmental Engineering, Wuhan University, Wuhan 430079 (China); Xiang, Luojing [Department of Environmental Engineering, Wuhan University, Wuhan 430079 (China); Université de Poitiers, UMR CNRS 7285, IC2MP, ENSIP, B1, 1 rue Marcel Doré, TSA 41105, Poitiers 86073 Cedex 9 (France); Huang, Qianqian; Qiu, Juanjuan [Department of Environmental Engineering, Wuhan University, Wuhan 430079 (China); Zhang, Hui, E-mail: eeng@whu.edu.cn [Department of Environmental Engineering, Wuhan University, Wuhan 430079 (China); Sivaiah, Matte Venkata; Baron, Fabien; Barrault, Joel; Petit, Sabine [Université de Poitiers, UMR CNRS 7285, IC2MP, ENSIP, B1, 1 rue Marcel Doré, TSA 41105, Poitiers 86073 Cedex 9 (France); Valange, Sabine, E-mail: sabine.valange@univ-poitiers.fr [Université de Poitiers, UMR CNRS 7285, IC2MP, ENSIP, B1, 1 rue Marcel Doré, TSA 41105, Poitiers 86073 Cedex 9 (France)

    2015-04-28

    Highlights: • Al-pillared Fe-smectite was synthesized and used as the photo-Fenton catalyst. • Response surface methodology was used to study the effects of reaction parameters. • The main intermediate products were identified by GC–MS technique. • A possible degradation pathway of Orange II was proposed. • All the generated products of Orange II were less toxic than the original dye. - Abstract: A ferric smectite clay material was synthesized and further intercalated with Al{sub 2}O{sub 3} pillars for the first time with the aim of evaluating its ability to be used as heterogeneous catalyst for the photo-Fenton decolorization of azo dye Orange II. UV irradiation was found to enhance the activity of the catalyst in the heterogeneous photo-Fenton process. Catalyst loading of 0.5 g/L and hydrogen peroxide concentration of 13.5 mM yielded a remarkable color removal, accompanied by excellent catalyst stability. The decolorization of Orange II followed the pseudo-first-order kinetics for initial dye concentrations from 20 to 160 mg/L. The central composite design (CCD) based on the response surface methodology (RSM) was applied to evaluate the effects of several operating parameters, namely initial pH, catalyst loading and hydrogen peroxide concentration, on the decolorization efficiency. The RSM model was derived and the response surface plots were developed based on the results. Moreover, the main intermediate products were separated and identified using gas chromatography–mass spectrometry (GC–MS) and a possible degradation pathway was proposed accordingly. The acute toxicity experiments illustrated that the Daphniamagna immobilization rate continuously decreased during 150 min reaction, indicating that the effluent was suitable for sequential biological treatment.

  17. Photo-Fenton oxidation of phenol and organochlorides (2,4-DCP and 2,4-D) in aqueous alkaline medium with high chloride concentration.

    Science.gov (United States)

    Luna, Airton J; Chiavone-Filho, Osvaldo; Machulek, Amilcar; de Moraes, José Ermírio F; Nascimento, Cláudio A O

    2012-11-30

    A highly concentrated aqueous saline-containing solution of phenol, 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4-dichlorophenol (2,4-DCP) was treated by the photo-Fenton process in a system composed of an annular reactor with a quartz immersion well and a medium-pressure mercury lamp (450 W). The study was conducted under special conditions to minimize the costs of acidification and neutralization, which are usual steps in this type of process. Photochemical reactions were carried out to investigate the influence of some process variables such as the initial concentration of Fe(2+) ([Fe(2+)](0)) from 1.0 up to 2.5 mM, the rate in mmol of H(2)O(2) fed into the system (FH(2)O(2);in) from 3.67 up to 7.33 mmol of H(2)O(2)/min during 120 min of reaction time, and the initial pH (pH(0)) from 3.0 up to 9.0 in the presence and absence of NaCl (60.0 g/L). Although the optimum pH for the photo-Fenton process is about 3.0, this particular system performed well in experimental conditions starting at alkaline and neutral pH. The results obtained here are promising for industrial applications, particularly in view of the high concentration of chloride, a known hydroxyl radical scavenger and the main oxidant present in photo-Fenton processes. PMID:22809483

  18. Advances in solar photoelectro-Fenton: Decolorization and mineralization of the Direct Yellow 4 diazo dye using an autonomous solar pre-pilot plant

    International Nuclear Information System (INIS)

    Highlights: • Assessment of an autonomous solar pre-pilot plant for solar photoelectro-Fenton. • Total decolorization and 96-97% mineralization for solutions of Direct Yellow 4 diazo dye at pH 3.0. • More rapid dye decay and mineralization at 0.50 mmol dm−3 Fe2+ and maximum current of 5.0 A. • 11 aromatics, 22 hydroxylated derivatives and 9 carboxylic acids detected as intermediates. • Release of NH4+ and SO42−as main inorganic ions. - Abstract: Here, an overview on the advances in solar photoelectro-Fenton (SPEF) is initially presented to show that it is the more potent electrochemical advanced oxidation process based on Fenton's reaction chemistry to remove organic pollutants from waters, due to the synergistic action of generated hydroxyl radicals and solar irradiation. As a novel advance for SPEF, an autonomous solar pre-pilot plant is proposed to make an energetically inexpensive process that can be viable at industrial level. The plant of 10 dm3 capacity contained a Pt/air-diffusion cell with 90.2 cm2 electrode area, coupled to a solar compound parabolic collectors (CPCs) photoreactor of 1.57 dm3 irradiation volume and to a solar photovoltaic panel that provides a maximum average current of 5.0 A. The oxidation ability of this plant was assessed by studying the degradation of Direct Yellow 4 (DY4) diazo dye, which involved the predominant destruction of organics by ·OH formed from Fenton's reaction between H2O2 generated at the cathode and added Fe2+, along with the photolysis of Fe(III)-carboxylate complexes with sunlight in the CPCs photoreactor. The effect of Fe2+ and dye contents as well as current on decolorization rate, substrate decay and mineralization rate was examined. About 96-97% mineralization was rapidly attained using 0.50 mmol dm−3 Fe2+ and up to 0.32 mmol dm−3 DY4 at 5.0 A. The DY4 decay always obeyed a pseudo-first-order kinetics. Eleven aromatic products, twenty two hydroxylated derivatives and nine short

  19. Fenton peroxidation improves the drying performance of waste activated sludge.

    Science.gov (United States)

    Dewil, Raf; Baeyens, Jan; Neyens, Elisabeth

    2005-01-31

    Advanced sludge treatment processes (AST) reduce the amount of sludge produced and improve the dewaterability, thus probably also affecting the heat transfer properties and the drying characteristics of the sludge. This paper studies the influence of the Fenton peroxidation on the thermal conductivity of the sludge. Results demonstrate that the Fenton's peroxidation positively influences the sludge cake consistency and hence enhances the mechanical dewaterability and the drying characteristics of the dewatered sludge. For the two sludges used in this study, i.e. obtained from the wastewater treatment plants (WWTP) of Tienen and Sint-Niklaas--the dry solids content of the mechanically dewatered sludge increased from 22.5% to 40.3% and from 18.7% to 35.2%, respectively. The effective thermal conductivity k(e) of the untreated and the peroxidized sludges is measured and used to determine the heat transfer coefficient h(s). An average improvement for k(e) of 16.7% (Tienen) and 5.8% (Sint-Niklaas) was observed. Consequently the value of h(s) increased with 15.6% (Tienen) and 5.0% (Sint-Niklaas). This increased heat transfer coefficient in combination with the increased dewaterability has direct implications on the design of sludge dryers. A plate-to-plate calculation of a multiple hearth dryer illustrates that the number of plates required to dry the peroxidized sludge to 90% DS is less than half the number of plates needed to dry untreated sludge. This results in reduced dryer dimensions or a higher capacity for an existing dryer of given dimensions. PMID:15629575

  20. Winery wastewater treatment by heterogeneous Photo-Fenton process and activated sludges; Depuracion de efluentes vinicolas ediante tratamientos Foto-Fenton en fase heterogenea y lodos activos

    Energy Technology Data Exchange (ETDEWEB)

    Mosteo, R.; Lalinde, N.; Ormad, Maria O. M.; Ovelleiro, J. L.

    2007-07-01

    The system composed by heterogeneous Photon-Fenton assisted by solar light and biological treatment based on activated sludge process treats adequately real winery wastewaters. the previous stage based on heterogeneous Photo-Fenton process produces a partial degradation of winery wastewaters and achieves a yield of degradation of organic matter (measured as TOC) close to 50%. The activated sludge process in simple stage doesn't present any operation problems (bulking phenomenon) and achieves a yield of degradation of organic matter of 90%. (Author) 16 refs.

  1. Preservation of glutamic acid-iron chelate into montmorillonite to efficiently degrade Reactive Blue 19 in a Fenton system under sunlight irradiation at neutral pH

    Science.gov (United States)

    Huang, Zhujian; Wu, Pingxiao; Gong, Beini; Yang, Shanshan; Li, Hailing; Zhu, Ziao; Cui, Lihua

    2016-05-01

    To further enhance the visible light responsive property and the chemical stability of Fe/clay mineral catalysts, glutamic acid-iron chelate intercalated montmorillonite (G-Fe-Mt) was developed. The physiochemical properties of G-Fe-Mt were investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (DRS), etc. The results showed that glutamic acid-iron chelates were successfully intercalated into the gallery of montmorillonite and the intercalated glutamic acid-iron chelate molecules were well preserved. The product G-Fe-Mt displayed excellent catalytic performance in heterogeneous photo-Fenton reaction under sunlight irradiation at acidic and neutral pH values. The chelation and the visible light responsiveness of glutamic acid produce a synergistic effect leading to greatly enhanced sunlight-Fenton reaction catalyzed by the heterogeneous G-Fe-Mt under neutral pH. G-Fe-Mt is a promising catalyst for advanced oxidation processes.

  2. A dual-chamber microbial fuel cell with conductive film-modified anode and cathode and its application for the neutral electro-Fenton process

    International Nuclear Information System (INIS)

    This study reports on the modification of the anode and the cathode in a dual-chamber microbial fuel cell (MFC) with a polypyrrole (PPy)/anthraquinone-2,6-disulfonate (AQDS) conductive film to boost its performance and the application of the MFC to drive neutral electron-Fenton reactions occurring in the cathode chamber. The MFC equipped with the conductive film-coated anode and cathode delivered the maximum power density of 823 mW cm-2 that was one order of magnitude larger than that obtained in the MFC with the unmodified electrodes. This was resulted from the enhanced activities of microbial metabolism in the anode and oxygen reduction in the cathode owing to the decoration of both electrodes with the PPy/AQDS composite. The MFC with the modified electrodes resulted in the largest rate of H2O2 generation in the cathode chamber by the two-electron reduction of O2. The increase in the concentration of H2O2 was beneficial for the enhancement in the amount of hydroxyl radicals produced by the reaction of H2O2 with Fe2+, thus allowing an increased oxidative ability of the electro-Fenton process towards the decolorization and mineralization of an azo dye (i.e., Orange II) at pH 7.0.

  3. Chlorinated and brominated phosphatidylcholines are generated under the influence of the Fenton reagent at low pH-a MALDI-TOF MS study.

    Science.gov (United States)

    Wu, Jianqing; Teuber, Kristin; Eibisch, Mandy; Fuchs, Beate; Schiller, Jürgen

    2011-01-01

    Lipid (phospholipid) oxidation is an increasingly important research topic due to the significant physiological relevance. The Fenton reaction, i.e. the transition metal catalyzed decomposition of H(2)O(2) is frequently used to generate hydroxyl radicals (HO*). Lipids with unsaturated fatty acyl residues are primarily converted by HO* radicals into peroxides. In contrast, chloro- and bromohydrins as well as dihalogenides are formed by the addition of HOCl or HOBr to the olefinic groups of the fatty acyl residues of lipids or under the influence of the enzyme myeloperoxidase (MPO) from Cl(-) and H(2)O(2). We will show here by using MALDI-TOF MS for product analysis that halogenated products may also be generated in the presence of the Fenton reagent, if either FeCl(2) or FeBr(2) is used. In the presence of FeSO(4), however, peroxides are exclusively generated. It will also be shown that the generation of halogen-containing products is a competing reaction with the cleavage of the double bond under generation of the corresponding aldehyde or carboxylic acid that is favored at prolonged incubation times and at elevated pH. PMID:20932962

  4. A novel Electro-Fenton-Like system using PW11O39Fe(III)(H2O)4- as an electrocatalyst for wastewater treatment

    International Nuclear Information System (INIS)

    A novel Electro-Fenton-Like (EFL) system was developed using the Keggin-type iron-substituted heteropolytungstate anion PW11O39Fe(III)(H2O)4- to substitute for Fe3+ in the conventional Electro-Fenton (EF) system for treatment of water polluted with organic compounds. The EFL system overcomes the drawback of low pH in conventional EF approaches and can be directly applied to neutral water treatment without any pH adjustment. Experimental results for dimethylphthalate (DMP) revealed complete degradation in 2 flow rate of 60 mL min-1. Total organic carbon removal of ∼56% was achieved at 120 min. Comparison with conventional EF oxidation revealed better efficiency of the present system for DMP degradation, suggesting its potential in treatment of water and wastewater with a relaxed pH requirement. The cumulative H2O2 concentration generated in situ at the electrode was monitored and the observed degradation rate constants kobs were determined for different initial DMP concentrations. The ligand exchange reaction of PW11O39Fe(III)(H2O)4- with H2O2 and the electron transfer resulting in hydroxyl radicals were examined using HPLC and electrochemical impedance spectroscopy. An electrocatalytic model involving inner-sphere electron transfer and a reaction mechanism for PW11O39Fe(III)(H2O)4- electrocatalytic reduction of H2O2 are proposed.

  5. Solar photoelectro-Fenton degradation of the herbicide 4-chloro-2-methylphenoxyacetic acid optimized by response surface methodology

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Segura, Sergi [Laboratori d' Electroquimica dels Materials i del Medi Ambient, Departament de Quimica Fisica, Facultat de Quimica, Universitat de Barcelona, Marti i Franques 1-11, 08028 Barcelona (Spain); Almeida, Lucio Cesar; Bocchi, Nerilso [Laboratorio de Pesquisas em Eletroquimica, Departamento de Quimica, Universidade Federal de Sao Carlos, C.P. 676, 13560-970 Sao Carlos - SP (Brazil); Brillas, Enric, E-mail: brillas@ub.edu [Laboratori d' Electroquimica dels Materials i del Medi Ambient, Departament de Quimica Fisica, Facultat de Quimica, Universitat de Barcelona, Marti i Franques 1-11, 08028 Barcelona (Spain)

    2011-10-30

    Highlights: {yields} The herbicide MCPA is quickly mineralized by solar photoelectro-Fenton. {yields} A CCRD allowed the optimization of current, Fe{sup 2+} content and solution pH. {yields} TOC, MCE and energy consumption are described by response surface methodology. {yields} Generated hydroxyl radical destroys MCPA and its aromatic oxidation by-products. {yields} UV light of solar irradiation photolyzes the Fe(III)-carboxylate complexes produced. - Abstract: A central composite rotatable design and response surface methodology (RSM) were used to optimize the experimental variables of the solar photoelectro-Fenton (SPEF) treatment of the herbicide 4-chloro-2-methylphenoxyacetic acid (MCPA). The experiments were made with a flow plant containing a Pt/air-diffusion reactor coupled to a solar compound parabolic collector (CPC) under recirculation of 10 L of 186 mg L{sup -1} MCPA solutions in 0.05 M Na{sub 2}SO{sub 4} at a liquid flow rate of 180 L h{sup -1} with an average UV irradiation intensity of about 32 W m{sup -2}. The optimum variables found for the SPEF process were 5.0 A, 1.0 mM Fe{sup 2+} and pH 3.0 after 120 min of electrolysis. Under these conditions, 75% of mineralization with 71% of current efficiency and 87.7 kWh kg{sup -1} TOC of energy consumption were obtained. MCPA decayed under the attack of generated hydroxyl radicals following a pseudo-first-order kinetics. Hydroxyl radicals also destroyed 4-chloro-2-methylphenol, methylhydroquinone and methyl-p-benzoquinone detected as aromatic by-products. Glycolic, maleic, fumaric, malic, succinic, tartronic, oxalic and formic acids were identified as generated carboxylic acids, which form Fe(III) complexes that are quickly photodecarboxylated by the UV irradiation of sunlight at the CPC photoreactor. A reaction sequence for the SPEF degradation of MCPA was proposed.

  6. Fabrication of magnetic carbon composites from peanut shells and its application as a heterogeneous Fenton catalyst in removal of methylene blue

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Lincheng, E-mail: zhoulc@lzu.edu.cn; Ma, Junjun; Zhang, He; Shao, Yanming; Li, Yanfeng

    2015-01-01

    Graphical abstract: Peanut shell magnetic carbon (PMC) were fabricated by carbonized the mixture of peanut shells and (NH{sub 4}){sub 3}Fe(C{sub 2}O{sub 4}){sub 3}. The obtained PMC exhibit high efficiency in catalysis oxidation methylene blue with the help of K{sub 2}S{sub 2}O{sub 8} and it can be easily separated from aqueous by external magnetic field. Meanwhile, the catalyst can be reused for seven times almost without decreased of activity. - Highlights: • Novel peanut shell magnetic carbon (PMC) catalysts were successfully synthesized. • PMC exhibited superior activity as a heterogeneous Fenton-like catalyst. • A high efficient Fenton-like system was set up for removal MB. • PMC posed excellent catalysis oxidation quality, stability and good reusability. - Abstract: Magnetic carbons were prepared from agricultural waste peanut shells and Ferric ammonium oxalate via a simple impregnation and carbonization process. The obtained composites were characterized by element analysis, MÖssbauer spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, X-ray diffraction, vibrating sample magnetometry and the Brunauer-Emmett-Teller surface area method, respectively. The magnetic carbon material was used as catalyst of heterogeneous Fenton reaction to remove methylene blue with the help of persulfate in waste water. The results indicated that both the removal rate and removal efficiency of this catalytic system are very excellent. The degradation efficiency was best (90% within 30 min) using initial concentrations of 0.5 g L{sup −1} persulfate and 40 mg L{sup −1} methylene blue. The removal mechanism was investigated by LC-MS. The catalyst retained its activity after seven reuses, indicating its good stability and reusability. It is inexpensive because it consists mainly of agricultural waste. Its porosity contributed to its high activity, which was achieved without any additional activation process. These indicating that the catalyst is

  7. Fabrication of magnetic carbon composites from peanut shells and its application as a heterogeneous Fenton catalyst in removal of methylene blue

    International Nuclear Information System (INIS)

    Graphical abstract: Peanut shell magnetic carbon (PMC) were fabricated by carbonized the mixture of peanut shells and (NH4)3Fe(C2O4)3. The obtained PMC exhibit high efficiency in catalysis oxidation methylene blue with the help of K2S2O8 and it can be easily separated from aqueous by external magnetic field. Meanwhile, the catalyst can be reused for seven times almost without decreased of activity. - Highlights: • Novel peanut shell magnetic carbon (PMC) catalysts were successfully synthesized. • PMC exhibited superior activity as a heterogeneous Fenton-like catalyst. • A high efficient Fenton-like system was set up for removal MB. • PMC posed excellent catalysis oxidation quality, stability and good reusability. - Abstract: Magnetic carbons were prepared from agricultural waste peanut shells and Ferric ammonium oxalate via a simple impregnation and carbonization process. The obtained composites were characterized by element analysis, MÖssbauer spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, X-ray diffraction, vibrating sample magnetometry and the Brunauer-Emmett-Teller surface area method, respectively. The magnetic carbon material was used as catalyst of heterogeneous Fenton reaction to remove methylene blue with the help of persulfate in waste water. The results indicated that both the removal rate and removal efficiency of this catalytic system are very excellent. The degradation efficiency was best (90% within 30 min) using initial concentrations of 0.5 g L−1 persulfate and 40 mg L−1 methylene blue. The removal mechanism was investigated by LC-MS. The catalyst retained its activity after seven reuses, indicating its good stability and reusability. It is inexpensive because it consists mainly of agricultural waste. Its porosity contributed to its high activity, which was achieved without any additional activation process. These indicating that the catalyst is potentially useful in the treatment of wastewater

  8. Removal of Refractory Organics from Biologically Treated Landfill Leachate by Microwave Discharge Electrodeless Lamp Assisted Fenton Process

    Directory of Open Access Journals (Sweden)

    Jiuyi Li

    2015-01-01

    Full Text Available Biologically treated leachate usually contains considerable amount of refractory organics and trace concentrations of xenobiotic pollutants. Removal of refractory organics from biologically treated landfill leachate by a novel microwave discharge electrodeless lamp (MDEL assisted Fenton process was investigated in the present study in comparison to conventional Fenton and ultraviolet Fenton processes. Conventional Fenton and ultraviolet Fenton processes could substantially remove up to 70% of the refractory organics in a membrane bioreactor treated leachate. MDEL assisted Fenton process achieved excellent removal performance of the refractory components, and the effluent chemical oxygen demand concentration was lower than 100 mg L−1. Most organic matters were transformed into smaller compounds with molecular weights less than 1000 Da. Ten different polycyclic aromatic hydrocarbons were detected in the biologically treated leachate, most of which were effectively removed by MDEL-Fenton treatment. MDEL-Fenton process provides powerful capability in degradation of refractory and xenobiotic organic pollutants in landfill leachate and could be adopted as a single-stage polishing process for biologically treated landfill leachate to meet the stringent discharge limit.

  9. Costs of the electrochemical oxidation of wastewaters: a comparison with ozonation and Fenton oxidation processes.

    Science.gov (United States)

    Cañizares, Pablo; Paz, Rubén; Sáez, Cristina; Rodrigo, Manuel A

    2009-01-01

    In the work described here the technical and economic feasibilities of three Advanced Oxidation Processes (AOPs) have been studied: Conductive-Diamond Electrochemical Oxidation (CDEO), Ozonation and Fenton oxidation. The comparison was made by assessing the three technologies with synthetic wastewaters polluted with different types of organic compounds and also with actual wastes (from olive oil mills and from a fine-chemical manufacturing plant). All three technologies were able to treat the wastes, but very different results were obtained in terms of efficiency and mineralization. Only CDEO could achieve complete mineralization of the pollutants for all the wastes. However, the efficiencies were found to depend on the concentration of pollutant (mass transfer control of the oxidation rate). Results obtained in the oxidation with ozone (at pH 12) or by Fenton's reagent were found to depend on the nature of the pollutants, and significant concentrations of oxidation-refractory compounds were usually accumulated during the treatment. Within the discharge limits that all of the technologies can reach, the economic analysis shows that the operating cost of Fenton oxidation is lower than either CDEO or ozonation, although CD\\EO can compete satisfactorily with the Fenton process in the treatment of several kinds of wastes. Likewise, the investment cost for the ozonation process seems to be higher than either CDEO or Fenton oxidation, regardless of the pollutant treated. PMID:18082930

  10. Optimization of the mineralization of a mixture of phenolic pollutants under a ferrioxalate-induced solar photo-Fenton process

    International Nuclear Information System (INIS)

    The mineralization of solutions containing a mixture of three phenolic compounds, gallic, p-coumaric and protocatechuic acids, in a ferrioxalate-induced solar photo-Fenton process was investigated. The reactions were carried out in a pilot plant consisting of a compound parabolic collector (CPC) solar reactor. An optimization study was performed combining a multivariate experimental design and neuronal networks that included the following variables: pH, temperature, solar power, air flow and initial concentrations of H2O2, Fe(II) and oxalic acid. Under optimal conditions, total elimination of the original compounds and 94% TOC removal of the mixture were achieved in 5 and 194 min, respectively. pH and initial concentrations of H2O2 and Fe(II) were the most significant factors affecting the mixture mineralization. The molar correlation between consumed hydrogen peroxide and removed TOC was always between 1 and 3. A detailed analysis of the reaction was presented. The values of the pseudo-first-order mineralization kinetic rate constant, kTOC, increased as initial Fe(II) and H2O2 concentrations and temperature increased. The optimum pH value also slightly increased with greater Fe(II) and hydrogen peroxide concentrations but decreased when temperature increased. ·OH and O2·- radicals were the main oxidative intermediate species in the process, although singlet oxygen (1O2) also played a role in the mineralization reaction.

  11. Application of Fenton's reagent as a pretreatment step in biological degradation of polyaromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Kelley, R.L.; Gauger, W.K.; Srivastava, V.J.

    1990-01-01

    Fenton's reagent (H{sub 2}O{sub 2} and Fe{sup ++}) has been used for chemical oxidation of numerous organic compounds in water treatment schemes. In this study, the Institute of Gas Technology (IGT) applied Fenton's treatment to polynuclear aromatic hydrocarbons (PAHs) and PAH-contaminated soils. Fenton's treatment was very reactive with PAHs, causing rapid modification of the parental compounds to oxidized products and complete degradation to CO{sub 2}. This treatment was more effective on chemically reactive PAHs, such as benzo(a)pyrene and phenanthrene. Important parameters and conditions for Fenton's treatment of PAHs in solution and soil matrices have been identified. As much as 99% of the PAHs on soil matrices can be removed by treatment with Fenton's reagent. 28 refs., 13 figs., 1 tab.

  12. Photo-fenton degradation of diclofenac: identification of main intermediates and degradation pathway.

    Science.gov (United States)

    Pérez-Estrada, Leónidas A; Malato, Sixto; Gernjak, Wolfgang; Agüera, Ana; Thurman, E Michael; Ferrer, Imma; Fernández-Alba, Amadeo R

    2005-11-01

    In recent years, the presence of pharmaceuticals in the aquatic environment has been of growing interest. These new contaminants are important because many of them are not degraded under the typical biological treatments applied in the wastewater treatment plants and represent a continuous input into the environment. Thus, compounds such as diclofenac are present in surface waters in all Europe and a crucial need for more enhanced technologies that can reduce its presence in the environment has become evident. In this sense, advanced oxidation processes (AOPs) represent a good choice for the treatment of hazardous nonbiodegradable pollutants. This work deals with the solar photodegradation of diclofenac, an antiinflammatory drug, in aqueous solutions by photo-Fenton reaction. A pilot-scale facility using a compound parabolic collector (CPC) reactor was used for this study. Results obtained show rapid and complete oxidation of diclofenac after 60 min, and total mineralization (disappearance of dissolved organic carbon, DOC) after 100 min of exposure to sunlight. Although diclofenac precipitates during the process at low pH, its degradation takes place in the homogeneous phase governed by a precipitation-redissolution-degradation process. Establishment of the reaction pathway was made possible by a thorough analysis of the reaction mixture identifying the main intermediate products generated. Gas chromatography-mass spectrometry (GC/ MS) and liquid chromatography coupled with time-of-flight mass spectrometry (LC/TOF-MS) were used to identify 18 intermediates, in two tentative degradation routes. The main one was based on the initial hydroxylation of the phenylacetic acid moiety in the C-4 position and subsequent formation of a quinone imine derivative that was the starting point for further multistep degradation involving hydroxylation, decarboxylation, and oxidation reactions. An alternative route was based on the transient preservation of the biphenyl amino moiety

  13. Aquifer evaluation at Fenton Hill, October and November 1980

    Energy Technology Data Exchange (ETDEWEB)

    Becker, N.M.; Purtymun, W.D.; Ballance, W.C.

    1981-10-01

    An aquifer test at the Fenton Hill Geothermal Site was performed on a volcanic aquifer used for water supply. The test was made to determine the yield from the aquifer and to predict the amount of depletion that would occur with increased production during the period 1981 to 1985. A step-discharge test indicated the aquifer would comfortably yield 100 gal per min (gpm) without excessive water level drawdown in the pumping well. Drawdown test results indicated that the average aquifer transmissivity and storage coefficient are 5000 gal per day per foot (gpd/ft) and 0.07, respectively. Using these parameters, a drawdown was estimated to be at least 42 ft at the pumping well due to a withdrawal of 500 acre-ft of water over 5 yr. However, the presence of ground water boundaries indicates the aquifer is of limited extent, and because of this, the water level decline would probably be much greater. Past water level data indicate that there is little recharge to the aquifer.

  14. Degradation of 4-Chlorophenol Solution by Synergetic Effect of Dual-frequency Ultrasound with Fenton Reagent

    Institute of Scientific and Technical Information of China (English)

    赵德明; 徐新华; 雷乐成; 汪大翚

    2005-01-01

    4-Chlorophenol (4-CP) solution was treated by dual-frequency ultrasound in conjunction with Fenton reagent, and obvious improvement in the 4-CP degradation rate was observed in this advanced oxidation process.Experimental results showed that ultrasonic intensity, saturating gas and pH value affected greatly the 4-CP removal rate. Among four different saturating gases (Ar, 02, air and N2), 4-CP degradation with Ar-saturated solution was the best. However, in the view of practical wastewater treatment, using oxygen as the saturating gas would be more economical. The addition of Fenton reagent followed the first-order kinetics and increased the 4-CP degradation rate.The 4-CP removal rate increased by around 126% within 15 rain treatment. The synergetic effect of dual-frequency ultrasound with Fenton reagent on 4-CP degradation was obviously observed.

  15. Investigation of a shallow aquifer near the Fenton Hill hot dry rock site using DC resistivity

    Energy Technology Data Exchange (ETDEWEB)

    Pearson, C.F.

    1981-10-01

    A shallow aquifer in the base of the Tertiary volcanic sequence was investigated using a series of 9 DC Schlumberger soundings taken within 10 km of the Fenton Hill hot dry rock geothermal site. The aquifer dips to the southwest following the top of the Abo formation, which acts as an aquiclude. Depth increases from 130 m in the eastern part of the study area to 260 m at 1.5 km west of the Fenton Hill site. Aquifer resistivities varied from 13..cap omega..-m to 126..cap omega..-m, which could be caused by variable permeability in the aquifer. Using results from empirical studies permeabilities ranging from 40 darcies to less than 0.3 darcies were estimated with the highest values occurring nearest to the Fenton Hill site.

  16. Efficient and Stable Carbon-coated Nickel Foam Cathodes for the Electro-Fenton Process

    International Nuclear Information System (INIS)

    Highlights: • Carbon-coated nickel foam (C@NF) was prepared by cycle coating carbon process. • Ni leaching can be effectively controlled at C@NF4 (4 cycle coating times) cathode. • C@NF4 exhibits excellent electro-Fenton performance with desirable stability. • C@NF4 exhibits low energy consumption for DMP degradation. - Abstract: Carbon-coated nickel foam (C@NF) electrodes are prepared via a simple and effective method, hydrothermal-carbonization cycle coating process, characterized by scanning electron microscopy (SEM) with energy dispersive spectrometer (EDS) and employed as the electro-Fenton (E-Fenton) cathode for degrading dimethyl phthalate (DMP) in aqueous solution. For the sake of comparison, nickel foam (NF) electrode and the conventional E-Fenton cathode (graphite gas diffusion electrode (GDE)) are also tested and compared. Experimental results indicate that nickel leaching can be effectively controlled at C@NF4 cathode (4 times cycle coating process), having great significance for promoting the application of NF in E-Fenton system. Moreover, C@NF4 cathode still presents excellent and effective performance on DMP degradation. DMP can be completely degraded within 2 h at −0.5 V and the total organic carbon (TOC) removal reaches as high as 82.1 %, which is almost 3 times as high as that at graphite GDE. Futhermore, the current efficiency for H2O2 generation at C@NF4 is enhanced by 12 times compared to that at NF, and consequently the energy consumption during DMP degradation at C@NF4 is obvious lower than that at both NF cathode and graphite GDE. From the obtained results it can be deduced that C@NF4 is promising to be an attractive alternative E-Fenton cathode for removing organic pollutants in wastewater

  17. Learning about Regiochemistry from a Hydrogen-Atom Abstraction Reaction in Water

    Science.gov (United States)

    Sears-Dundes, Christopher; Huon, Yoeup; Hotz, Richard P.; Pinhas, Allan R.

    2011-01-01

    An experiment has been developed in which the hydrogen-atom abstraction and the coupling of propionitrile, using Fenton's reagent, are investigated. Students learn about the regiochemistry of radical formation, the stereochemistry of product formation, and the interpretation of GC-MS data, in a safe reaction that can be easily completed in one…

  18. Optimization of the electro-Fenton and solar photoelectro-Fenton treatments of sulfanilic acid solutions using a pre-pilot flow plant by response surface methodology

    Energy Technology Data Exchange (ETDEWEB)

    El-Ghenymy, Abdellatif [Laboratori d' Electroquimica dels Materials i del Medi Ambient, Departament de Quimica Fisica, Facultat de Quimica, Universitat de Barcelona, Marti i Franques 1-11, 08028 Barcelona (Spain); Departement de Chimie, Faculte des Sciences, Universite Abdelmalek Essaadi, M' Hannech II B.P.2121, C.P. 93002 Tetouan (Morocco); Garcia-Segura, Sergi; Rodriguez, Rosa Maria [Laboratori d' Electroquimica dels Materials i del Medi Ambient, Departament de Quimica Fisica, Facultat de Quimica, Universitat de Barcelona, Marti i Franques 1-11, 08028 Barcelona (Spain); Brillas, Enric, E-mail: brillas@ub.edu [Laboratori d' Electroquimica dels Materials i del Medi Ambient, Departament de Quimica Fisica, Facultat de Quimica, Universitat de Barcelona, Marti i Franques 1-11, 08028 Barcelona (Spain); El Begrani, Mohamed Soussi; Abdelouahid, Ben Ali [Departement de Chimie, Faculte des Sciences, Universite Abdelmalek Essaadi, M' Hannech II B.P.2121, C.P. 93002 Tetouan (Morocco)

    2012-06-30

    Highlights: Black-Right-Pointing-Pointer Quicker degradation of sulfanilic acid by solar photoelectro-Fenton than electro-Fenton. Black-Right-Pointing-Pointer The same optimized current density, Fe{sup 2+} content and pH for both processes by CCRD. Black-Right-Pointing-Pointer Description of TOC, energy cost and current efficiency by response surface methodology. Black-Right-Pointing-Pointer Fe(III)-carboxylate complexes as main by-products after electro-Fenton. Black-Right-Pointing-Pointer Photolysis of these complexes by UV irradiation of sunlight in solar photoelectro-Fenton. - Abstract: A central composite rotatable design and response surface methodology were used to optimize the experimental variables of the electro-Fenton (EF) and solar photoelectro-Fenton (SPEF) degradations of 2.5 L of sulfanilic acid solutions in 0.05 M Na{sub 2}SO{sub 4}. Electrolyses were performed with a pre-pilot flow plant containing a Pt/air diffusion reactor generating H{sub 2}O{sub 2}. In SPEF, it was coupled with a solar photoreactor under an UV irradiation intensity of ca. 31 W m{sup -2}. Optimum variables of 100 mA cm{sup -2}, 0.5 mM Fe{sup 2+} and pH 4.0 were determined after 240 min of EF and 120 min of SPEF. Under these conditions, EF gave 47% of mineralization, whereas SPEF was much more powerful yielding 76% mineralization with 275 kWh kg{sup -1} total organic carbon (TOC) energy consumption and 52% current efficiency. Sulfanilic acid decayed at similar rate in both treatments following a pseudo-first-order kinetics. The final solution treated by EF contained a stable mixture of tartaric, acetic, oxalic and oxamic acids, which form Fe(III) complexes that are not attacked by hydroxyl radicals formed from H{sub 2}O{sub 2} and added Fe{sup 2+}. The quick photolysis of these complexes by UV light of sunlight explains the higher oxidation power of SPEF. NH{sub 4}{sup +} was the main inorganic nitrogen ion released in both processes.

  19. Photo-fenton process: Optimization and decolourization and mineralization of reactive blue 222 dye

    OpenAIRE

    Shumaila Kiran; Shahzad Ali Shahid

    2012-01-01

    Dye house effluents of textile industries leads to severe environmental problems when disposed to aquatic bodies without proper treatment. This work was carried out to optimize the Photo-Fenton process for decolorization and mineralization of a commercial textile dye, Reactive Blue 222. The effect of different process parameters on decolorization efficiency of Photo-Fenton process was investigated. The optimal conditions for process were observed as; pH level 3.5, H2O2 concentration 1× 10-2M,...

  20. Personal Review: Progress and prospect in electro-Fenton process for wastewater treatment

    Institute of Scientific and Technical Information of China (English)

    JIANG Cheng-chun; ZHANG Jia-fa

    2007-01-01

    As a novel advanced oxidation process (AOP), electro-Fenton process is powerful for degrading most organic compounds including toxic and non-biodegradable ones, and so has attracted great attention. This paper reviews this process in detail including the mechanism, electrolytic bath, electrode materials, aerations and operation parameters. The application of electro-Fenton method in wastewater treatment is evaluated and summarized. Future work in this field is suggested, and three main directions of new electrode exploitation, development of assisted technologies and mechanistic study should be strengthened.

  1. Pyrene removal from contaminated soils by modified Fenton oxidation using iron nano particles

    OpenAIRE

    Sahand Jorfi; Abbas Rezaee; Ghasem-ali Moheb-ali; Nemat alah Jaafarzadeh

    2013-01-01

    Background The problems related to conventional Fenton oxidation, including low pH required and production of considerable amounts of sludge have led researchers to investigate chelating agents which might improve the operating range of pH and the use of nano iron particle to reduce the excess sludge. The pyrene removal from contaminated soils by modified Fenton oxidation at neutral pH was defined as the main objective of the current study. Methods Varying concentrations of H2O2 (0-500 mM) an...

  2. Modified Fenton oxidation of pyrene in contaminated soils using iron nano oxides

    OpenAIRE

    Sahand Jorfi; Abbas Rezaee; Nemat Allah Jaafarzadeh Haghighi Fard; Ghasem Ali Mohebali

    2013-01-01

    Background and Aim: Problems related to conventional Fenton oxidation, including neccesity of having a low pH and production of considerable amounts of sludge, have prompted researchers to consider chelating agents to improve the pH operating range and iron nano-oxide particles to reduce excess sludge. The main objective of this study was to remove pyrene from contaminated soils by a modified Fenton oxidation method  at neutral pH. Materials and Methods: Experiments were conducted using vario...

  3. Fenton氧化法修复石油污染土壤的研究进展%Remediation of petroleum contaminated soil by Fenton oxidation method: A review

    Institute of Scientific and Technical Information of China (English)

    李方敏; 柳红霞

    2012-01-01

    The traditional Fenton oxidation (Fe2+/H2 02 ) reaction has some drawbacks when used for sml remediation, including rapid reaction rate, regular additions of Fe2+ and the requirement of low pH 〈3, which limited its remediation efficiency for petroleum hydrocarbons contaminated soil. In this paper, recent progress on modified oxidants and catalysts of the Fenton reaction, and effects of the modification on removal efficiencies in petroleum-contaminated soils were reviewed. Soil properties, reaction conditions, pollutant structure and the heterogeneous catalyst specific surface areas were major factors influencing the removal efficiencies. The method of ultrasonic pre-treatment was introduced, which increases the contact probability of Fenton reagent with the petroleum contaminants petroleum hydrocarbon pollutants by the subsequent also prospected. desorbed from soils, and it improves biodegradability of microbial processes. The research trends in this field were%传统的Fenton氧化法(Fe2+/H2O2)因反应速度过快、需要定期补充Fe2+、控制pH值≤3等方面的限制而影响到石油烃类污染土壤的修复效果.本文综述了近年来Fenton反应中氧化剂、催化剂的改进及其对土壤中石油污染物的去除效率,揭示了土壤性质、反应条件、污染物结构及非均相催化剂比表面积等因素对去除效率的影响,介绍了超声波前置处理后,Fenton试剂与土壤上解吸的石油污染物接触几率的增加及石油烃类可生物降解性的提高,促进了微生物的后续处理效果,并对该领域的研究趋势进行了展望.

  4. Amorphous Fe²⁺-rich FeOx loaded in mesoporous silica as a highly efficient heterogeneous Fenton catalyst.

    Science.gov (United States)

    Wang, Min; Shu, Zhu; Zhang, Lingxia; Fan, Xiangqian; Tao, Guiju; Wang, Yongxia; Chen, Lisong; Wu, Meiying; Shi, Jianlin

    2014-06-28

    A simple physical-vapor-infiltration (PVI) method using ferrocene as the iron source, has been developed to load FeOx into the pore channels of mesoporous silica SBA-15. The obtained FeOx/SBA-15 composite has a high loading amount of FeOx (e.g. 26.64 wt% Fe content obtained at PVI duration 17 h and calcination temperature 450 °C) but unblocked pore channels thanks to the unique preparation strategy. The FeOx species are amorphous, rich of Fe(2+) and have been highly dispersed as a nanocoating onto the pore channel surface. The FeOx/SBA-15 composite was used as a heterogeneous Fenton catalyst to degrade Acid orange 7 (AO7). It showed a high catalytic activity and degradation efficiency, which was attributed to the high proportion of Fe(2+) in the amorphous FeOx and their favorable adsorption capability for the dye. The influences of the PVI duration, the calcination temperature and the Fenton reaction conditions (FeOx/SBA-15 dosages, H2O2 dosages and initial pH value) on the catalytic activity were investigated in detail. PMID:24816279

  5. Fenton法降解水中布洛芬%Degradation of ibuprofen by Fenton oxidation

    Institute of Scientific and Technical Information of China (English)

    杨丽娟; 胡翔; 吴晓楠

    2012-01-01

    采用benton法降解水中布洛芬,考察了H2O2投加量、FeSO4·7H2O与H2O2的比值、初始pH、反应时间等因素对布洛芬去除率的影响,通过正交实验确定影响作用大小依次为:[Fe2+]:[H2O2]的物质的量之比〉H2O2的投加量〉pH值,最佳的反应工艺条件为:H2O2的投加量为3mL-L1,[Fe2+]:[H2O2]的物质的量之比为1:10,反应初始pH值为3,反应时间为40min.在最佳条件下布洛芬的去除率达到86%以上.同时对布洛芬降解反应动力学进行了研究,发现Fenton降解布洛芬符合二级反应动力学规律.%The degradation of ibuprofen was investigated by using Fenton method. The effects of different tactors on the removal efficiency of ibuprofen were evaluated. The order of main factors were O O rthogo ptimal nal experiments as follow: the mole ratio of Fe2+ to H2O2 〉 H2O2 dosage 〉 reaction conditions were as follow : dosage of H2O2 was 3 mL. L- 1, the mole ratio 1 : 10, the initial pH was 3 and the reaction time was 40 min. Under such conditions, the ibuprofen was over 86%. The reaction kinetics was also investigated. The degradation of oxidation was accord with the second order kinetics.

  6. UV-assisted Fenton digestion of rice for the determination of trace cadmium by hydride generation atomic fluorescence spectrometry.

    Science.gov (United States)

    Yu, Huimin; Ai, Xi; Xu, Kailai; Zheng, Chengbin; Hou, Xiandeng

    2016-02-21

    A new digestion method using UV-assisted Fe(0) Fenton reaction was developed for the determination of trace Cd in rice by hydride generation atomic fluorescence spectrometry. The proposed method integrated the advantages of simplicity, small dose of reagents, low cost and moderate reaction conditions, and was successfully utilized to analyze a Certified Reference Material (CRM) and real rice samples. A 1 mL mixture of the sample and reagents (0.0500 g rice powder, 0.2% (m/v) Fe(0), 0.75% (v/v) HNO3 and 18% (v/v) H2O2) was irradiated by UV-light for 50 min and then a clear solution was obtained by separating excess Fe(0) with a magnet prior to spectral analysis. The limit of detection (LOD) for Cd was found to be 0.02 mg kg(-1) and the relative standard deviation was better than 5.0% at a concentration level of 0.40 mg kg(-1). The recovery obtained by analyzing the CRM was 103% and spiked recoveries with 0.40 mg kg(-1) Cd in rice samples were 93% and 101%. The t-test proved that there is no significant difference between the certified value and the determined value of the CRM, and between the proposed method and microwave-assisted digestion coupled with inductively coupled plasma mass spectrometry (MWD-ICP-MS) at 95% confidence level. PMID:26759832

  7. Fe, Co, Ni nanocrystals encapsulated in nitrogen-doped carbon nanotubes as Fenton-like catalysts for organic pollutant removal.

    Science.gov (United States)

    Yao, Yunjin; Chen, Hao; Lian, Chao; Wei, Fengyu; Zhang, Dawei; Wu, Guodong; Chen, Benjin; Wang, Shaobin

    2016-08-15

    Magnetic metal M (M=Fe, Co, Ni) nanocrystals encapsulated in nitrogen-doped carbon nanotubes (M@N-C) were fabricated conveniently using dicyandiamide as a C/N precursor, and exhibited varying activities toward Fenton-like reaction. The surface morphology and structure of the M@N-C catalysts were characterized and an efficient catalytic degradation performance, high stability, and excellent reusability were observed. In addition, several operational factors, such as initial dye concentration, oxidant type (peroxymonosulfate, peroxydisulfate and H2O2) and dosage, reaction temperature, and dye type as well as stability of the composite were extensively evaluated in view of the practical applications. The results showed that various transition metals M significantly affected the structures and performances of the catalysts, and specially, their activity followed the order of Co>Fe>Ni in the presence of peroxymonosulfate. Moreover, HO⁡ and SO4(-) radicals participating in the process were evidenced using quenching experiments, and a rational mechanism was proposed based on a non-radical process and the free radical process. Control experiments revealed that the enhanced active sites were mainly ascribed to the synergistic effects between the metal nanocrystals and nitrogen-doped carbon. The findings of this study elucidated that encapsulation of nanocrystals in nitrogen-doped carbon nanotubes was an effective strategy to enhance the overall catalytic activity. PMID:27111426

  8. Design of a neutral three-dimensional electro-Fenton system with foam nickel as particle electrodes for wastewater treatment

    International Nuclear Information System (INIS)

    Highlights: ► Remove RhB by a novel 3D-E-Fenton system using foam nickel as particle electrodes. ► The 3D-E-Fenton system exhibit much higher RhB removal efficiency than the counterpart 3D-E and E-Fenton system. ► Foam nickel as a particle electrode displays good oxygen reduction activity. ► The performance of RhB removal was optimized by some operating parameters and the optimization pH was the neutral. - Abstract: In this work, we demonstrate a novel three-dimensional electro-Fenton system (3D-E-Fenton) for wastewater treatment with foam nickel, activated carbon fiber and Ti/RuO2–IrO2 as the particle electrodes, the cathode, and the anode respectively. This 3D-E-Fenton system could exhibit much higher rhodamine B removal efficiency (99%) than the counterpart three-dimensional electrochemical system (33%) and E-Fenton system (19%) at neutral pH in 30 min. The degradation efficiency enhancement was attributed to much more hydroxyl radicals generated in the 3D-E-Fenton system because foam nickel particle electrodes could activate molecular oxygen to produce ·O2− via a single-electron transfer pathway to subsequently generate more H2O2 and hydroxyl radicals. This is the first observation of molecular oxygen activation over the particle electrodes in the three-dimensional electrochemical system. These interesting findings could provide some new insight on the development of high efficient E-Fenton system for wastewater treatment at neutral pH.

  9. Design of a neutral three-dimensional electro-Fenton system with foam nickel as particle electrodes for wastewater treatment

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Wei [Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079 (China); Ai, Zhihui, E-mail: jennifer.ai@mail.ccnu.edu.cn [Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079 (China); Zhang, Lizhi [Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079 (China)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer Remove RhB by a novel 3D-E-Fenton system using foam nickel as particle electrodes. Black-Right-Pointing-Pointer The 3D-E-Fenton system exhibit much higher RhB removal efficiency than the counterpart 3D-E and E-Fenton system. Black-Right-Pointing-Pointer Foam nickel as a particle electrode displays good oxygen reduction activity. Black-Right-Pointing-Pointer The performance of RhB removal was optimized by some operating parameters and the optimization pH was the neutral. - Abstract: In this work, we demonstrate a novel three-dimensional electro-Fenton system (3D-E-Fenton) for wastewater treatment with foam nickel, activated carbon fiber and Ti/RuO{sub 2}-IrO{sub 2} as the particle electrodes, the cathode, and the anode respectively. This 3D-E-Fenton system could exhibit much higher rhodamine B removal efficiency (99%) than the counterpart three-dimensional electrochemical system (33%) and E-Fenton system (19%) at neutral pH in 30 min. The degradation efficiency enhancement was attributed to much more hydroxyl radicals generated in the 3D-E-Fenton system because foam nickel particle electrodes could activate molecular oxygen to produce {center_dot}O{sub 2}{sup -} via a single-electron transfer pathway to subsequently generate more H{sub 2}O{sub 2} and hydroxyl radicals. This is the first observation of molecular oxygen activation over the particle electrodes in the three-dimensional electrochemical system. These interesting findings could provide some new insight on the development of high efficient E-Fenton system for wastewater treatment at neutral pH.

  10. Fenton oxidation treatment of spent wash-off liquor for reuse in reactive dying

    International Nuclear Information System (INIS)

    The use of clean and high quality water in textile dyeing process is very expensive. In this study, the potential of reusing Fenton treated wash-off wastewater generated at the end of reactive dyeing was investigated. The treated wastewater was used in several dyeings employing three widely used reactive dyes, C. I. Reactive Yellow 145, C. I. Reactive Red 194, and C. I. Reactive Blue 221. Experimental results showed that at acidic pH (3.5) using optimized quantities of FeSO/sub 4/ and H/sub 2/O/sub 2/, Fenton process yielded a significant reduction (80-99%) of colour and COD in 30 minutes of treatment time. New dyeings were then carried out in Fenton decolourized wash-off wastewater, and dyed fabric samples were subjected to quality evaluations in terms of wash fastness, crock fastness, and colour difference properties (delta L*, delta c*, delta h*, and delta E*). This study concluded that Fenton oxidation was an efficient method for the treatment of textile wash-off wastewater, and treated liquor can be effectively recycled in next dyeing, without compromising quality parameters. This method proved to be an eco-friendly process owing to the fact that it did not use any fresh water. (author)

  11. Electro-Fenton decolourisation of dyes in an airlift continuous reactor using iron alginate beads.

    Science.gov (United States)

    Iglesias, O; Rosales, E; Pazos, M; Sanromán, M A

    2013-04-01

    In this study, electro-Fenton dye degradation was performed in an airlift continuous reactor configuration by harnessing the catalytic activity of Fe alginate gel beads. Electro-Fenton experiments were carried out in an airlift reactor with a working volume of 1.5 L, air flow of 1.5 L/min and 115 g of Fe alginate gel beads. An electric field was applied by two graphite bars connected to a direct current power supply with a constant potential drop. In this study, Lissamine Green B and Reactive Black 5 were selected as model dyes. Fe alginate gel beads can be used as an effective heterogeneous catalyst for the degradation of organic dyes in the electro-Fenton process, as they are more efficient than the conventional electrochemical techniques. At optimal working conditions (3 V and pH 2), the continuous process was performed. For both dyes, the degree of decolourisation increases when the residence time augments. Taking into account hydrodynamic and kinetic behaviour, a model to describe the reactor profile was obtained, and the standard deviation between experimental and theoretical data was lower than 6%. The results indicate the suitability of the electro-Fenton technique to oxidise polluted effluents in the presence of Fe alginate gel beads. Moreover, the operation is possible in a continuous airlift reactor, due to the entrapment of iron in the alginate matrix. PMID:22851224

  12. Application of electro-Fenton technology to remediation of polluted effluents by self-sustaining process.

    Science.gov (United States)

    Fernández de Dios, Maria Ángeles; Iglesias, Olaia; Pazos, Marta; Sanromán, Maria Ángeles

    2014-01-01

    The applicability of electro-Fenton technology to remediation of wastewater contaminated by several organic pollutants such as dyes and polycyclic aromatic hydrocarbons has been evaluated using iron-enriched zeolite as heterogeneous catalyst. The electro-Fenton technology is an advanced oxidation process that is efficient for the degradation of organic pollutants, but it suffers from the high operating costs due to the need for power investment. For this reason, in this study microbial fuel cells (MFCs) were designed in order to supply electricity to electro-Fenton processes and to achieve high treatment efficiency at low cost. Initially, the effect of key parameters on the MFC power generation was evaluated. Afterwards, the degradation of Reactive Black 5 dye and phenanthrene was evaluated in an electro-Fenton reactor, containing iron-enriched zeolite as catalyst, using the electricity supplied by the MFC. Near complete dye decolourization and 78% of phenanthrene degradation were reached after 90 min and 30 h, respectively. Furthermore, preliminary reusability tests of the developed catalyst showed high degradation levels for successive cycles. The results permit concluding that the integrated system is adequate to achieve high treatment efficiency with low electrical consumption. PMID:24723828

  13. Treatment of textile effluent by chemical (Fenton's Reagent) and biological (sequencing batch reactor) oxidation

    International Nuclear Information System (INIS)

    The removal of organic compounds and colour from a synthetic effluent simulating a cotton dyeing wastewater was evaluated by using a combined process of Fenton's Reagent oxidation and biological degradation in a sequencing batch reactor (SBR). The experimental design methodology was first applied to the chemical oxidation process in order to determine the values of temperature, ferrous ion concentration and hydrogen peroxide concentration that maximize dissolved organic carbon (DOC) and colour removals and increase the effluent's biodegradability. Additional studies on the biological oxidation (SBR) of the raw and previously submitted to Fenton's oxidation effluent had been performed during 15 cycles (i.e., up to steady-state conditions), each one with the duration of 11.5 h; Fenton's oxidation was performed either in conditions that maximize the colour removal or the increase in the biodegradability. The obtained results allowed concluding that the combination of the two treatment processes provides much better removals of DOC, BOD5 and colour than the biological or chemical treatment alone. Moreover, the removal of organic matter in the integrated process is particularly effective when Fenton's pre-oxidation is carried out under conditions that promote the maximum increase in wastewater biodegradability.

  14. Application of Electro-Fenton Technology to Remediation of Polluted Effluents by Self-Sustaining Process

    Directory of Open Access Journals (Sweden)

    Maria Ángeles Fernández de Dios

    2014-01-01

    Full Text Available The applicability of electro-Fenton technology to remediation of wastewater contaminated by several organic pollutants such as dyes and polycyclic aromatic hydrocarbons has been evaluated using iron-enriched zeolite as heterogeneous catalyst. The electro-Fenton technology is an advanced oxidation process that is efficient for the degradation of organic pollutants, but it suffers from the high operating costs due to the need for power investment. For this reason, in this study microbial fuel cells (MFCs were designed in order to supply electricity to electro-Fenton processes and to achieve high treatment efficiency at low cost. Initially, the effect of key parameters on the MFC power generation was evaluated. Afterwards, the degradation of Reactive Black 5 dye and phenanthrene was evaluated in an electro-Fenton reactor, containing iron-enriched zeolite as catalyst, using the electricity supplied by the MFC. Near complete dye decolourization and 78% of phenanthrene degradation were reached after 90 min and 30 h, respectively. Furthermore, preliminary reusability tests of the developed catalyst showed high degradation levels for successive cycles. The results permit concluding that the integrated system is adequate to achieve high treatment efficiency with low electrical consumption.

  15. Fenton-like Degradation of MTBE: Effects of Iron Counter Anion and Radical Scavengers

    Science.gov (United States)

    Fenton-driven oxidation of Methyl tert-butyl ether (MTBE) (0.11-0.16 mM) in batch reactors containing ferric iron (5 mM), hydrogen peroxide (H2O2) (6 mM) (pH=3) was performed to investigate MTBE transformation mechanisms. Independent variables included the form of iron (Fe) (Fe2(...

  16. Investigating the Electro-Fenton (EF Process Performance in Treating Highly Formaldehyde-Polluted Industrial Wastewater

    Directory of Open Access Journals (Sweden)

    Amir Bagheri

    2012-10-01

    Full Text Available Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 Background and Objectives: Formaldehyde is a toxic substance and harmful to human beings and the environmental health. Therefore, the effluents containing formaldehyde have to be efficiently treated before discharging into the environment. This study was aimed at investigating the efficiency of Electro-Fenton (EF Process in pre-treating industrial wastewater containing high concentrations of formaldehyde.Materials and Methods: The effect of the important operational variables including pH, current density, H2O2 dosage, and reaction time were evaluated on the degradation of 7500 mg/L formaldehyde using batch tests. The EFP batch reactor was consisted of a cylindrical glass column with 5.20 cm in internal diameter and 34.50 cm in height. Working volume of the reactor was 500 mL.Results: The maximum formaldehyde removal was obtained at alkaline pH of 10, H2O2 concentration of 10 mM/min, current intensity 8.5 mA/cm2, and the reaction time of 6 minute. Furthermore, aerating the EFP cell could enhance the formaldehyde removal. Complete removal of formaldehyde was obtained under the abovementioned operational conditions. Conclusion: This study demonstrated that the EFP is capable of reducing high concentration of formaldehyde (7500 mg/l to the level suitable for biological post-treatment. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso

  17. Development of a trickle bed reactor of electro-Fenton process for wastewater treatment

    Energy Technology Data Exchange (ETDEWEB)

    Lei, Yangming [Key Laboratory of Reservoir Aquatic Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 401122 (China); School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Liu, Hong, E-mail: liuhong@cigit.ac.cn [Key Laboratory of Reservoir Aquatic Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 401122 (China); Shen, Zhemin, E-mail: zmshen@sjtu.edu.cn [School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Wang, Wenhua [School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2013-10-15

    Highlights: • An electrochemical trickle bed reactor was composed of C-PTFE-coated graphite chips. • The trickle bed reactor had a high H{sub 2}O{sub 2} production rate in a dilute electrolyte. • An azo dye was effectively decomposed by the electro-Fenton process in the reactor. -- Abstract: To avoid electrolyte leakage and gas bubbles in the electro-Fenton (E-Fenton) reactors using a gas diffusion cathode, we developed a trickle bed cathode by coating a layer composed of carbon black and polytetrafluoroethylene (C-PTFE) onto graphite chips instead of carbon cloth. The trickle bed cathode was optimized by single-factor and orthogonal experiments, in which carbon black, PTFE, and a surfactant were considered as the determinant of the performance of graphite chips. In the reactor assembled by the trickle bed cathode, H{sub 2}O{sub 2} was generated with a current of 0.3 A and a current efficiency of 60%. This performance was attributed to the fine distribution of electrolyte and air, as well as the effective oxygen transfer from the gas phase to the electrolyte–cathode interface. In terms of H{sub 2}O{sub 2} generation and current efficiency, the developed trickle bed reactor had a performance comparable to that of the conventional E-Fenton reactor using a gas diffusion cathode. Further, 123 mg L{sup −1} of reactive brilliant red X-3B in aqueous solution was decomposed in the optimized trickle bed reactor as E-Fenton reactor. The decolorization ratio reached 97% within 20 min, and the mineralization reached 87% within 3 h.

  18. Decolourisation of dyes under electro-Fenton process using Fe alginate gel beads

    International Nuclear Information System (INIS)

    Highlights: ► Catalytic activity of Fe alginate gel beads for the remediation of wastewater was tested. ► New electro-Fenton process for the remediation of polluted wastewater. ► Continuous dye treatment without operational problem with high removal. - Abstract: This study focuses on the application of electro-Fenton technique by use of catalytic activity of Fe alginate gel beads for the remediation of wastewater contaminated with synthetic dyes. The Fe alginate gel beads were evaluated for decolourisation of two typical dyes, Lissamine Green B and Azure B under electro-Fenton process. After characterization of Fe alginate gel beads, the pH effect on the process with Fe alginate beads and a comparative study of the electro-Fenton process with free Fe and Fe alginate bead was done. The results showed that the use of Fe alginate beads increases the efficiency of the process; moreover the developed particles show a physical integrity in a wide range of pH (2–8). Around 98–100% of dye decolourisation was obtained for both dyes by electro-Fenton process in successive batches. Therefore, the process was performed with Fe alginate beads in a bubble continuous reactor. High color removal (87–98%) was attained for both dyes operating at a residence time of 30 min, without operational problems and maintaining particle shapes throughout the oxidation process. Consequently, the stable performance of Fe alginate beads opens promising perspectives for fast and economical treatment of wastewater polluted by dyes or similar organic contaminants.

  19. Orientation of minimum principal stress in the hot dry rock geothermal reservoir at Fenton Hill, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Burns, K.L.

    1991-01-01

    The stress field at the source of microearthquakes in the interior of the hot dry rock geothermal reservoir at Fenton Hill appears to be different to the far field stress outside the reservoir. The stress field seems to be re-oriented prior to failure, during the course of processes that inflate the reservoir. The state of stress, both inside and outside, the hot dry rock (HDR) geothermal reservoir at Fenton Hill, is important in predicting the course of stress-dependent processes, and in transferring HDR technology developed at Fenton Hill, to sites, such as at Clearlake in California, where the stress field is expected to be substantially different. The state of stress at Fenton Hill is not well known because of limitations in stress measuring technology. It is necessary to use a variety of indirect methods and seek an estimate of the stress. 5 refs.

  20. Solar photoelectro-Fenton degradation of the antibiotic metronidazole using a flow plant with a Pt/air-diffusion cell and a CPC photoreactor

    International Nuclear Information System (INIS)

    Highlights: • Degradation of metronidazole solutions at pH 3.0 by EF and SPEF in a flow plant. • High recalcitrance of the antibiotic and its products to be destroyed by ·OH radicals. • Only 53% mineralization by the most potent SPEF process at 55.4 mA cm−2. • 5 heterocyclic products, 12 hydroxylated derivatives and 2 carboxylic acids were found. • Release of NO3− ion and generation of persistent N-products and N-volatile species. - Abstract: The degradation of 10 dm3 of solutions of the heterocyclic antibiotic metronidazole in 0.10 mol dm−3 Na2SO4 of pH 3.0 has been comparatively studied by electro-Fenton (EF) and solar photoelectro-Fenton (SPEF). Experiments were performed in a solar flow plant equipped with a Pt/air-diffusion cell and coupled to a compound parabolic collector (CPC) photoreactor. A very weak mineralization was found for the EF process in the dark, indicating a large recalcitrance of heterocyclic compounds to be destroyed by hydroxyl radicals formed at the Pt anode from water oxidation and mainly in the bulk from Fenton's reaction between added Fe2+ and cathodically generated H2O2. The quick photolysis of intermediates by UV radiation from sunlight enhanced largely the mineralization process by SPEF. The effect of applied current density and Fe2+ and drug contents on the SPEF treatment was examined. The best process was found for 1.39 mmol dm−3 metronidazole with 0.50 mmol dm−3 Fe2+ at 55.4 mA cm−2 giving 53% mineralization, 36% mineralization current efficiency and 0.339 kWh (g DOC)−1 in 300 min. Metrodinazole was completely removed and its decay obeyed a pseudo-first-order kinetics. LC-MS analysis allowed identifying five heterocyclic products and twelve hydroxylated derivatives. Ion-exclusion HPLC analysis revealed that final oxalic and oxamic acids were practically removed at the end of electrolysis due to the efficient photolysis of their Fe(III) complexes by sunlight. The initial N of metronidazole gave NO3

  1. Treatment of phenol-containing wastewater by UV-Fenton process%UV/Fenton处理苯酚废水的研究

    Institute of Scientific and Technical Information of China (English)

    王来斐

    2012-01-01

    UV—Fenton process was used to treat simulant phenol—containing wastewater, the initial mass concentrations of phenol and CODcx were 300 and 760 mg/L respectively. The effects of pH value, dosage of H2O2(30%) and FeSO4·7H2O, reaction time and some other factors on the removal rates of phenol and CODcr were discussed. The results showed that, the optimal condition for UV-Fenton process treating phenol-containing wastewater was as follows: the solution pH value was 3, the dosage of H2O2 and FeSO4·7H2O were 2.5 mL/L and 0.020 g/L respectively, the reaction time was 90 min. Under the above condition, the removal rates of phenol and CODcr reached 95% and 90% respectively. It could be seen that, UV -Fenton process was effective for the treatment of phenol-containing wastewater.%采用UV/Fenton联合体系降解苯酚模拟废水,苯酚的初始质量浓度为300 mg/L,CODCr的初始质量浓度为760 mg/L.探讨了pH值、H2O2 (30%)和FeSO4· 7H2O投加量、反应时间等因素对苯酚和CODCr去除率的影响.结果表明,UV/Fenton联合体系降解苯酚废水的最佳工艺条件是:溶液pH值为3、H2O2投加量为2.5 mL/L、FeSO4·7H2O投加量为0.020 g/L、反应时间为90 min.此时,苯酚的去除率为95%,CODCr的去除率为90%.UV/Fenton联合体系能较好地处理苯酚废水.

  2. Solvothermal in situ synthesis of Fe3O4-multi-walled carbon nanotubes with enhanced heterogeneous Fenton-like activity

    International Nuclear Information System (INIS)

    Graphical abstract: After purification, the multi-wall carbon nanotubes (MWCNTs) act as seeds for Fe3O4 nanoparticles heterogeneous nucleation. The Fe3O4 nanoparticles with diameter range of 4.2–10.0 nm synthesized in situ on the MWCNTs under solvothermal condition. The formed nano Fe3O4-MWCNTs decolorized the Acid Orange II effectively via Fenton-like reaction. Highlights: ► The amount of water tunes size and size distribution of the Fe3O4 nanoparticles (FNs). ► FNs are homogeneously coated on the multi-walled carbon nanotubes (MWCNTs). ► FNs have diameters in the range of 4.2–10.0 nm, average grain size of 7.4 nm. ► Fe3O4-MWCNTs are used as a Fenton-like catalyst to decompose Acid Orange II. ► Fe3O4-MWCNTs displayed a higher activity than nanometer-size Fe3O4. -- Abstract: Fe3O4-multi-walled carbon nanotubes (Fe3O4-MWCNTs) hybrid materials were synthesized by a solvothermal process using acid treated MWCNTs and iron acetylacetonate in a mixed solution of ethylene glycol and ultrapure water. The materials were characterized using X-ray powder diffraction, scanning and transmission electron microscopy, X-ray photoelectron spectroscopy, and vibrating sample magnetometry. The results showed that a small amount of water in the synthesis system played a role in controlling crystal phase formation, size of Fe3O4, and the homogeneous distribution of the Fe3O4 nanoparticles deposited on the MWCNTs. The Fe3O4 nanoparticles had diameters in the range of 4.2–10.0 nm. They displayed good superparamagnetism at room temperature and their magnetization was influenced by the reaction conditions. They were used as a Fenton-like catalyst to decompose Acid Orange II and displayed a higher activity than nanometer-size Fe3O4.

  3. Effect of non-modified and modified nanodiamond particles by Fenton reaction on human endothelial cells

    Directory of Open Access Journals (Sweden)

    K. Solarska

    2010-12-01

    Full Text Available Purpose: The use of carbon nanoparticles in medicine is increasing due to their high biocompatibility. Nanopowders are one of the best materials which can be used in medicine on medical implants and surgical tools. DPP (Diamond Powder Particles obtained by different methods which can be expected to affect their properties, including biocompatibility, were compared. The aim of the present study was to compare the biocompatibility of Diamond Powder Particles (DPP obtained by detonation method and graphite on the basis of their interactions with human endothelial cells.Design/methodology/approach: The effect of nanodiamonds on cell proliferation HUVEC-ST and production of reactive oxygen species (ROS and reactive nitrogen species (RNS was studied. We used FT-IR Spectroscopy attributive chemical function groups.Findings: In this subject the material characterization of nanodiamond powders and influence on endothelial cells.Practical implications: Biological research with endothelial cells and nanodiamond powder are the introduction to application in human’s treatment.Originality/value: Nanodiamond powders with chemical modified surface.

  4. Synthesis of Chitosan-Grafted-Poly (Methyl Methacrylate) with Fentons Reagent (Fe2+ - H2O2) as a Redox Initiator

    International Nuclear Information System (INIS)

    Graft copolymerization of poly(methyl methacrylate) (PMMA) onto chitosan fiber has been successfully carried out using Fentons Reagent which is consisted of hydrogen peroxide (H2O2) as initiator and ferrous ammonium sulphate (FAS) as co-catalyst under inert atmosphere in an aqueous medium. The PMMA homopolymer formed during the reaction was removed from the grafted copolymer by Soxhlet extraction using acetone as the solvent. The grafting percentage and efficiency obtained were 449.16 % and 85.94 %, respectively. The maximum grafting percentage and efficiency were achieved when 0.3 g chitosan copolymerized with 3 mL monomer at 70 degree Celsius for 120 minutes with [FAS] = 6 x 10-5 M, [H2O2] = 6 x 10-3 M and 8 mL water. The grafted copolymers were characterized by using FTIR, DSC, TGA and SEM analysis. The presence of absorbance band at 1724 cm-1 provided strong evidence of grafting. (author)

  5. Optimizing the solar photo-Fenton process in the treatment of contaminated water. Determination of intrinsic kinetic constants for scale-up

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, Miguel [Universidad de Los Andes, Escuela Basica de Ingenieria, La Hechicera, Merida (Venezuela); Malato, Sixto [Plataforma Solar de Almeria, Tabernas (PSA) (Spain); Pulgarin, Cesar [Institute of Environmental Engineering, Laboratory for Environmental Biotechnology, Swiss Federal Institute of Technology (EPFL), CH-1015 Lausanne (Switzerland); Contreras, Sandra; Curco, David; Gimenez, Jaime; Esplugas, Santiago [Department d' Enginyeria Quimica i Metallurgia, Universitat de Barcelona, Marti i Franques 1, 08028 Barcelona (Spain)

    2005-10-01

    The elimination of aromatic compounds present in surface water by photo-Fenton with sunlight as the source of radiation was studied. The concentrations of Fe{sup 3+} and H{sub 2}O{sub 2} are key factors for this process. A solar simulator and a prototype parabolic collector were used as laboratory-scale reactors to find the parameters of those key factors to be used in the CPC (compound parabolic collector) pilot plant reactor. The initial mineralization rate constant (k{sub obs}) was determined and evaluated at different Fe{sup 3+} and H{sub 2}O{sub 2} concentrations to find the best values for maximum efficiency. In all the experiments the mineralization of an aqueous phenol solution was described by assuming a pseudo-first-order reaction. The intrinsic kinetic constants not dependent on the lighting conditions were also estimated for scale-up. (author)

  6. AbstractApplication of Fenton-like process using iron nano oxides for pyrene removal from contaminated soils

    OpenAIRE

    S. Jorfi; Rezaee, A.; N Jaafarzadeh Haghighifard; G.A Moheb-ali

    2014-01-01

    Background and objectives: Because of problems dealing with bioremediation including being time consuming, low efficiency and toxicity to biota, application of advanced oxidation processes with higher efficiency and shorter remediation time have been considered for removal of hydrophobic hydrocarbons from contaminated soils. A great interest has been directed to Fenton oxidation because of its simplicity and high oxidation potential. The objective of this study was to determine the Fenton-lik...

  7. Novel Method for Breakthrough Removal of Azo Dye from Aqueous Environment Using Integrated Coagulation and Fenton Process

    OpenAIRE

    Sherine Awad; Usama Eldemerdash

    2014-01-01

    Fenton process has proven to be efficient in the removal of color and chemical oxygen demand (COD) from the aqueous environment. However, the environment, health, and economic constraints on the dosage of hydrogen peroxide represent a limitation towards a wide practical use of this approach. In this study, a novel approach is proposed; this includes the treatment with ferrous oxide through coagulation followed by integrated Fenton process. However, the excess ferrous and ferric ions from the ...

  8. Degradation of tyrosol by a novel electro-Fenton process using pyrite as heterogeneous source of iron catalyst.

    Science.gov (United States)

    Ammar, Salah; Oturan, Mehmet A; Labiadh, Lazhar; Guersalli, Amor; Abdelhedi, Ridha; Oturan, Nihal; Brillas, Enric

    2015-05-01

    Tyrosol (TY) is one of the most abundant phenolic components of olive oil mill wastewaters. Here, the degradation of synthetic aqueous solutions of 0.30 mM TY was studied by a novel heterogeneous electro-Fenton (EF) process, so-called EF-pyrite, in which pyrite powder was the source of Fe(2+) catalyst instead of a soluble iron salt used in classical EF. Experiments were performed with a cell equipped with a boron-doped diamond anode and a carbon-felt cathode, where TY and its products were destroyed by hydroxyl radicals formed at the anode surface from water oxidation and in the bulk from Fenton's reaction between Fe(2+) and H2O2 generated at the cathode. Addition of 1.0 g L(-1) pyrite provided an easily adjustable pH to 3.0 and an appropriate 0.20 mM Fe(2+) to optimize the EF-pyrite treatment. The effect of current on mineralization rate, mineralization current efficiency and specific energy consumption was examined under comparable EF and EF-pyrite conditions. The performance of EF-pyrite was 8.6% superior at 50 mA due to self-regulation of soluble Fe(2+) by pyrite. The TY decay in this process followed a pseudo-first-order kinetics. The absolute rate constant for TY hydroxylation was 3.57 × 10(9) M(-1) s(-1), as determined by the competition kinetics method. Aromatic products like 3,4-dihydroxyphenylethanol, 4-hydroxyphenylacetic acid, 4-hydroxybenzoic acid, 3,4-dihydroxybenzoic acid and catechol, as well as o-benzoquinone, were identified by GC-MS and reversed-phase HPLC. Short-chain aliphatic carboxylic acids like maleic, glycolic, acetic, oxalic and formic were quantified by ion-exclusion HPLC. Oxalic acid was the major and most persistent product found. Based on detected intermediates, a plausible mineralization pathway for TY by EF-pyrite was proposed. PMID:25720669

  9. Photo-Fenton degradation of the herbicide 2,4-D in aqueous medium at pH conditions close to neutrality.

    Science.gov (United States)

    Conte, Leandro O; Schenone, Agustina V; Alfano, Orlando M

    2016-04-01

    A theoretical and experimental study of the photo-Fenton degradation of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) in water is presented. A kinetic model derived from a reaction sequence is proposed using the ferrioxalate complex as iron source for conditions of pH = 5. The kinetic model was employed to predict the concentrations of 2,4-D, 2,4-dichlorophenol (2,4-DCP), hydrogen peroxide (HP) and oxalate (Ox) in a flat plate laboratory reactor irradiated with a solar simulator. Two types of incident irradiation levels were tested by different combinations of attenuation filters. The effects of the oxalate/Fe(+3) molar ratio (Ox/Fe), the reaction temperature (T) and the 2,4-D/HP molar ratio (R) on the photo-Fenton process were also investigated. For low radiation level and operating conditions of R = 50 and T = 50 °C, a 2,4-D conversion of 95.6% was obtained after 180 min. Moreover, the 2,4-D conversion was almost 100% in only 120 min when the system was operated under the same operating conditions and high radiation level. From the proposed model and the experimental data, the corresponding kinetic parameters were estimated applying a nonlinear regression method. A good agreement between the kinetic model and experimental data, for a wide range of simulated solar operating conditions, was observed. For 2,4-D, 2,4-DCP, HP and Ox concentrations, the calculated RMSE were 1.21 × 10(-2), 5.45 × 10(-3), 2.86 × 10(-1) and 2.65 × 10(-2) mM, respectively. PMID:26800432

  10. Modified Fe{sub 3}O{sub 4}- hydroxyapatite nanocomposites as heterogeneous catalysts in three UV, Vis and Fenton like degradation systems

    Energy Technology Data Exchange (ETDEWEB)

    Valizadeh, S., E-mail: valizadehsolmaz@yahoo.com; Rasoulifard, M.H., E-mail: m_h_rasoulifard@znu.ac.ir; Dorraji, M.S. Seyed, E-mail: dorraji@znu.ac.ir

    2014-11-15

    Graphical abstract: - Highlights: • Photocatalytic degradation of dye by Ag modified HAP under visible light. • Study of Fenton like degradation of dye by transition metal ions modified HAP. • Comparison of catalytic systems according to Langmuir-Hinshelwood kinetic expression. - Abstract: The magnetite-hydroxyapatite (M-HAP) nanocomposites were prepared by a chemical co- precipitation procedure and characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and diffuse reflectance spectra (DRS). The ability of the synthesized catalyst for photocatalytic degradation of Acid Blue 25 (AB25), as an organic dye, under UV irradiation was studied. The catalyst was modified employing transition metals (Mn, Fe, Co, Ni, Cu and Zn) trying to improve the catalytic performance of HAP in absence of UV irradiation and in the presence of hydrogen peroxide i.e. a Fenton like reaction. The best results obtained for Cu and Co modified M-HAPs and the effect of operational parameters such pH, amount of catalyst and hydrogen peroxide concentration was studied. In order to investigate the performance of HAP based photocatalyst in visible light region, M-HAP was modified with silver ions. At the end, Langmuir-Hinshelwood kinetic expression used to evaluate and compare the catalytic systems. The strongest degradation activity was observed for Ag-M-HAP/Vis system because of Ag{sub 3}PO{sub 4} formation. Apparent reaction rate constant (K{sub app}) by Ag-M-HAP/Vis was 63, 36 and 19 times faster than Cu-M-HAP(II)/H{sub 2}O{sub 2}, Co-M-HAP(II)/H{sub 2}O{sub 2} and M-HAP (I)/UV systems, respectively.

  11. Degradation of industrial azo dye in aqueous solution by heterogeneous Fenton process (fly ash/H2O2

    Directory of Open Access Journals (Sweden)

    Bečelić-Tomin Milena R.

    2012-01-01

    Full Text Available The aim of this study was to investigate the possibilities and efficiency of heterogeneous Fenton process with the use of fly ash from thermal power plants Kolubara, Serbia, as the catalyst in the degradation of industrial azo dye Zetanyl Rosso B-NG. The effects of various experimental parameters such as pH, temperature, concentration of fly ash, the initial concentration of H2O2 and initial concentration of dye on the kinetics and efficiency of decolorization were investigated. Simultaneous leaching of iron from fly ash was monitored. The optimum conditions had been determined, and it was found that decolorization efficiency obtained after 150 min of reaction, was about 98.9%. The optimal parameters were: initial pH = 3; [H2O2]0 = 6 mM; dosage of fly ash = 0.1g/l (for dye concentration of 100 mg/l; temperature = 22 °C. The effectiveness of the applied treatment for mineralization of dye solution was investigated, under optimal conditions determined by the examination of various factors influencing the decolorization process at the specified contact time. The maximum achieved reduction of total organic carbon content was 96.5%. The results indicate that the reuse of fly ash as the catalyst support in •OH production in this process achieves significant efficiency in terms of decolorization, 94.4% and mineralization, 89.6%. Futhermore, fly ash showed adequate stability during the reaction (low iron leaching, concentrations under optimal reaction condition were about 2 mg/l.

  12. Mesoporous core–shell Fenton nanocatalyst: a mild, operationally simple approach to the synthesis of adipic acid.

    Science.gov (United States)

    Patra, Astam K; Dutta, Arghya; Bhaumik, Asim

    2013-09-01

    Mesoporous nanoparticles composed of γ-Al2O3 cores and α-Fe2O3 shells were synthesized in aqueous medium. The surface charge of γ-Al2O3 helps to form the core–shell nanocrystals. The core–shell structure and formation mechanism have been investigated by wide-angle XRD, energy-dispersive X-ray spectroscopy, and elemental mapping by ultrahigh-resolution (UHR) TEM and X-ray photoelectron spectroscopy. The N2 adsorption–desorption isotherm of this core–shell materials, which is of type IV, is characteristic of a mesoporous material having a BET surface area of 385 m2 g(−1) and an average pore size of about 3.2 nm. The SEM images revealed that the mesoporosity in this core–shell material is due to self-aggregation of tiny spherical nanocrystals with sizes of about 15–20 nm. Diffuse-reflectance UV/Vis spectra, elemental mapping by UHRTEM, and wide-angle XRD patterns indicate that the materials are composed of aluminum oxide cores and iron oxide shells. These Al2O3@Fe2O3 core–shell nanoparticles act as a heterogeneous Fenton nanocatalyst in the presence of hydrogen peroxide, and show high catalytic efficiency for the one-pot conversion of cyclohexanone to adipic acid in water. The heterogeneous nature of the catalyst was confirmed by a hot filtration test and analysis of the reaction mixture by atomic absorption spectroscopy. The kinetics of the reaction was monitored by gas chromatography and 1H NMR spectroscopy. The new core–shell catalyst remained in a separate solid phase, which could easily be removed from the reaction mixture by simple filtration and the catalyst reused efficiently. PMID:24167824

  13. Ultrasound coupled with Fenton oxidation pre-treatment of sludge to release organic carbon, nitrogen and phosphorus

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Changxiu [School of Environment, Tsinghua University, Beijing 100084 (China); Jiang, Jianguo, E-mail: jianguoj@mail.tsinghua.edu.cn [School of Environment, Tsinghua University, Beijing 100084 (China); Key Laboratory for Solid Waste Management and Environment Safety, Ministry of Education of China (China); Collaborative Innovation Center for Regional Environmental Quality, Tsinghua University, Beijing (China); Li, De' an [School of Environment, Tsinghua University, Beijing 100084 (China)

    2015-11-01

    We focused on the effects of ultrasound and Fenton reagent in ultrasonic coupling Fenton oxidation (U + F) pre-treatment processes on the disintegration of wastewater treatment plant sludge. The results demonstrated that U + F treatment could significantly increase soluble COD, TOC, total N, proteins, total P and PO{sub 4}{sup 3−} concentrations in sludge supernatant. This method was more effective than ultrasonic (U) or Fenton oxidation (F) treatment alone. U + F treatment increased the soluble COD by 2.1- and 1.4-fold compared with U and F alone, respectively. U + F treatment increased the total N and P by 1.7- and 2.2-fold, respectively, compared with F alone. After U + F treatment, sludge showed a considerably finer particle size and looser microstructure based on scanning electron microscopy, and the highest OH· signal intensity increased from 568.7 by F treatment to 1106.3 using electron spin resonance. This demonstrated that U + F treatment induces disintegration of sludge and release of organic carbon, nitrogen and phosphorus better. - Highlights: • Combined ultrasound–Fenton pre-treatment was proposed for sludge disintegration. • Ultrasound–Fenton significantly increased carbon, nitrogen and phosphorus release. • Higher level of OH· was detected after combined disintegration than Fenton.

  14. Reuse of recalcitrant-rich anaerobic effluent as dilution water after enhancement of biodegradability by Fenton processes.

    Science.gov (United States)

    Arimi, Milton M; Zhang, Yongjun; Namango, Saul S; Geißen, Sven-Uwe

    2016-03-01

    Anaerobic digestion is used to treat effluents with a lot of organics, such as molasses distillery wastewater (MDW) which is the effluent of bioethanol production from molasses. The raw MDW requires a lot of dilution water before biodigestion, while the digested MDW has high level of recalcitrants which are problematic for its discharge. This study investigated ferric coagulation, Fenton, Fenton-like (with ferric ions as catalyst) processes and their combinations on the biodegradability of digested MDW. The Fenton and Fenton-like processes after coagulation increased the MDW biodegradability defined by (BOD5/COD) from 0.07 to (0.4-0.6) and saved 50% of H2O2 consumed in the classic Fenton process. The effluent from coagulation coupled to a Fenton-like process was used as dilution water for the raw MDW before the anaerobic digestion. The process was stable with volumetric loading of approx. 2.7 g COD/L/d. It resulted in increased overall biogas recovery and significantly decreased the demand for the dilution water. PMID:26692412

  15. Selection of electrode material and treatment of printing wastewater by EF-Fenton%阴极电芬顿法电极材料的选择及处理印染废水的研究

    Institute of Scientific and Technical Information of China (English)

    石申; 刘正伟; 奚吉; 金少波; 周宇松

    2014-01-01

    The selection criteria of electrode material in EF-Fenton system was discussed,and by comparing the performance, titanium coated ruthenium iridium electrode was selected as the anode material,ACF electrode as the cathode material. A self-made Electro-Fenton reactor was used to treat printing wastewater,the effects of various factors on the treatment of printing wastewater were experimentally analyzed. The results show that the EF-Fenton system is effective in the treatment of printing wastewater,and the optimal reaction conditions are as follows:reaction pH value of 3,FeSO4 dosage of 150 mg/L,aeration capacity of 0.1 m3/h,voltage of 9 V,time of 40 min. The maximum removal rate of COD reaches 73.5%.%讨论了阴极电芬顿体系中电极材料的选择标准,并通过比较选择以钛涂钌铱电极、活性碳纤维电极作为阳极、阴极材料。利用自制的电芬顿反应器,对影响体系处理印染废水效果的各相关因素进行研究。结果表明:阴极电芬顿法处理印染废水效果良好,最佳反应条件:pH值为3,FeSO4投加量为150 mg/L,曝气量为0.1 m3/h,电压为9 V,反应时间为40 min,此时COD的去除率最高,可达到73.5%。

  16. Photo-Fenton oxidation with immobilized iron of a dye of the textile industry; Oxidacion foto-Fenton con hierro inmovilizado de un colorante de la industria textil

    Energy Technology Data Exchange (ETDEWEB)

    Riaza Frutos, A.; Manzano Quinones, M. A.; Quiroga Alonso, J. M.

    2006-07-01

    The oxidation of a representative dye of the textile industry (Orange II) has been studied. The primary degradation and mineralization are easy to follow through spectrophotometric and TOC measures, respectively. It was used the photo-Fenton process under conditions of heterogeneous catalysis with the iron ions (III) fixed in a perfluorinated membrane that resists to the oxidation process. The main variables it has been studied the main variable that influence in the process to the object of establishing the best operation conditions. Likewise, it has been carried out the mineralization and kinetic study under the optimal conditions. (Author) 26 refs.

  17. Tratamento de águas contaminadas por diesel/biodiesel utilizando processo Fenton Treatment of water contaminated by diesel/biodiesel using Fenton process

    Directory of Open Access Journals (Sweden)

    Teofani Koslides Mitre

    2012-06-01

    Full Text Available A contaminação de águas por misturas diesel/biodiesel pode causar grandes impactos ambientais, relacionados à presença de compostos orgânicos recalcitrantes e tóxicos, inviabilizando o uso de processos biológicos de tratamento. A avaliação da biodegradabilidade, nas proporções B0, B25, B50, B75 e B100 (os números especificam o percentual em massa de biodiesel na mistura, indicou que a adição de biodiesel em teores acima de 50% aumenta a biodegradabilidade, alcançando 60 e 80% para B50 e B75, respectivamente. Na aplicação do processo Fenton, a remoção da matéria orgânica foi superior a 80% em todas as misturas, exceto para B0, que apresentou remoção máxima de 50%. A oxidação por Fenton se ajustou a um modelo cinético de pseudo-segunda ordem em relação à concentração de matéria orgânica, e resultou em aumento da biodegradabilidade de até 150%.Waters contaminated with diesel/biodiesel and their blends can cause major environmental impacts, due to the presence of toxic and recalcitrant organic compounds, which invalidate the use of biological treatment processes. Evaluation of biodegradability of the blends B0, B25, B50, B75 and B100 (the numbers specify the mass percentage of biodiesel in the blend indicated that the addition of biodiesel at concentrations above 50% increased biodegradation, reaching 60 and 80% for B50 and B75, respectively. When the Fenton process was used, removal of organic matter was greater than 80 % in all blends, except for B0, which showed maximum removal of 60%. Oxidation by Fenton was fitted with a pseudo-second order kinetic model in relation to the concentration of organic matter and resulted in increased biodegradation of up to 150%.

  18. Winery wastewater treatment by a combined process: long term aerated storage and Fenton's reagent.

    Science.gov (United States)

    Lucas, Marco S; Mouta, Maria; Pirra, António; Peres, José A

    2009-01-01

    The degradation of the organic pollutants present in winery wastewater was carried out by the combination of two successive steps: an aerobic biological process followed by a chemical oxidation process using Fenton's reagent. The main goal of this study was to evaluate the temporal characteristics of solids and chemical oxygen demand (COD) present in winery wastewater in a long term aerated storage bioreactor. The performance of different air dosage daily supplied to the biologic reactor, in laboratory and pilot scale, were examined. The long term hydraulic retention time, 11 weeks, contributed remarkably to the reduction of COD (about 90%) and the combination with the Fenton's reagent led to a high overall COD reduction that reached 99.5% when the mass ratio (R = H(2)O(2)/COD) used was equal to 2.5, maintaining constant the molar ratio H(2)O(2)/Fe(2+)=15. PMID:19700849

  19. Evaluation of Fenton's Reagent and Activated Persulfate for Treatment of a Pharmaceutical Waste Mixture in Groundwater

    DEFF Research Database (Denmark)

    Bennedsen, Lars Rønn; Søgaard, Erik Gydesen; Kakarla, Prasad;

    -going bench tests evaluating treatment of site groundwater and soil using modified Fenton's reagent and activated persulfate. These tests are investigating oxidant stability, oxidation efficiency, metals mobilization and, for the persulfate, different activating agents, including NaOH, chelated iron, and...... modified Fenton's reagent. The stability of the oxidants will be determined under simulated aquifer conditions, with and without catalyst or activating agents. Once an optimal activation technique has been determined, oxidation efficiency towards the complex mix of contaminants will be measured in terms of...... contaminant loss. The treatment efficiency will also be evaluated on the basis of pre- and post-treatment toxicity tests. Due to the presence of significant quantities of mercury and cyanide in the target treatment zone (up to 1500 kg and 2500 kg, respectively), a key of objective of these tests is to...

  20. Fenton Process Coupled to Ultrasound and UV Light Irradiation for the Oxidation of a Model Pollutant

    Directory of Open Access Journals (Sweden)

    Karen E. Barrera-Salgado

    2016-01-01

    Full Text Available The Fenton process coupled to photosonolysis (UV light and Us, using Fe2O3 catalyst supported on Al2O3, was used to oxidize a model pollutant like acid green 50 textile dye (AG50. Dye degradation was followed by AG50 concentration decay analyses. It was observed that parameters like iron content on a fixed amount of catalyst supporting material, catalyst annealing temperature, initial dye concentration, and the solution pH influence the overall treatment efficiency. High removal efficiencies of the model pollutant are achieved. The stability and reusability tests of the Fe2O3 catalyst show that the catalyst can be used up to three cycles achieving high discoloration. Thus, this catalyst is highly efficient for the degradation of AG50 in the Fenton process.

  1. Fenton's reagent minimum dosage for remediation of water contaminated with dyes

    Directory of Open Access Journals (Sweden)

    Gina Terán

    2015-09-01

    Full Text Available Effluents from the textile industry not only represent a latent threat to biodiversity on our planet but also to humans due to the pollution generated by industrial dyes. In this study a Fenton process was evaluated for the decoloration of water contaminated with yellow 160, blue 81 and red 190 with an initial concentration of 3300 mg.L-1 and a chemical oxygen demand of 1719 mg.L-1. Changes in pH and molar doses of ferrous sulfate and hydrogen peroxide were evaluated. The Fenton process allowed 99,9% removal of organic matter and 100% removal of turbidity when it worked at pH 3,5 and molar dose Fe+2/ H2O2 between 1:3 and 1:5. By spectrophotometric scanning and measurement of redox potential, it was shown that the quality of decontaminated water resembled the ultrapure water type I.

  2. PERBANDINGAN EFEKTIFITAS DISINFEKTAN KAPORIT, HIDROGEN PEROKSIDA, DAN PEREAKSI FENTON (H2O2/Fe2+

    Directory of Open Access Journals (Sweden)

    Didik Setiawan

    2013-11-01

    Full Text Available Tujuan dari penelitian ini adalah untuk menentukan konsentrasi optimum dan efektifitas hidrogen peroksida dan pereaksi Fenton sebagai disinfektan dibandingkan dengan kaporit. Efektivitas disinfeksi ditentukan berdasarkan beberapa parameter yaitu: koefisien fenol disinfektan dan kualitas air yang dihasilkan yang diukur melalui pH, oksigen terlarut (DO, dissolved oxygen, dan suhunya serta harga disinfektan itu sendiri. Analisis statistik ANOVA dua arah tanpa interaksi  pada tingkat kesalahan 0.01 dilakukan guna menentukan disinfektan paling efektif dan konsentrasi optimumnya. Uji koefisien fenol dilakukan dengan mencampurkan disinfektan dengan konsentrasi tertentu dengan bakteri Salmonella typhosa dan Staphyllococcus aureuskemudian membandingkan hasilnya dengan fenol.Hasil pengamatan menunjukkan bahwa koefisien fenol dari kaporit, hidrogen peroksida, dan reagen Fenton berturut-turut adalah 4, 6, dan 6. Air yang dihasilkan oleh kaporit mempunyai pH, DO dan suhu berturut-turut adalah 10.07 - 9.2, 6.63-8.07 mgL-1, dan 28.5-28.13oC. Air yang didisinfeksi dengan hidrogen peroksida mempunyai pH,DO, dan suhu berturut-turut adalah 9.03-7.33, 6.93-9.40 mgL-1  , dan 28.5-28.03oC. Sedangkan air hasil didisinfeksi dengan reagen Fenton mempunyai pH, DO, dan suhu berturut-turut adalah 5.97-4.57, 7.40-8.57 mgL-1 , dan 28.47-28.07oC.Meskipun kaporit paling murah, namun dari segi kesehatan hidrogen peroksida merupakan reagen yang paling aman dan paling efektif karena dengan daya disinfeksi enam kali dibandingkan fenol, tidak meninggalkan residu yang membahayakan. Fenton, dilain pihak, meskipun mempunyai daya disinfeksi setara dengan hidrogen peroksida, namun menghasilkan ion Besi (III dalam air sehingga memerlukan pengolahan lebih jauh.Dengan demikian, secara keseluruhan hidrogen peroksida merupakan disinfektan paling efektif dari ketiganya. The purpose of this study is to determine the optimum concentration and the effectiveness of hydrogen peroxide and Fenton

  3. Applicability of nano zero valent iron (nZVI) in sono - Fenton process

    Science.gov (United States)

    Taha, M. R.; Ibrahim, A. H.; Amat, R. C.; Azhari, A. W.

    2014-04-01

    Fenton process is one of the advanced oxidation processes (AOPs) used to remove complex organic pollutants in wastewater. In this study, instead of iron sulfate (FeSO4), nano zero valent iron (nZVI) was used as a major source of ferrous iron (Fe2+). In order to enhance the process, ultrasound was utilized in this study. Results show that, with the aid of ultrasound, nZVI produced more Fe2+ compared to FeSO4 at pH 2. Furthermore, combination of higher intensity and longer sonication time in Fenton process acceleratde the chemical oxygen demand (COD) removal from palm oil mill effluent (POME). Through the process, 80% of COD content was removed within 2 hours instead of 24 hours of silent degradation.

  4. Biological hazard evaluation of a pharmaceutical effluent before and after a photo-Fenton treatment.

    Science.gov (United States)

    Novoa-Luna, Karen Adriana; Mendoza-Zepeda, Arisbeht; Natividad, Reyna; Romero, Rubi; Galar-Martínez, Marcela; Gómez-Oliván, Leobardo Manuel

    2016-11-01

    The aim of this study was to evaluate the biological hazard of a pharmaceutical effluent before and after treatment. For the former, the determined 96h-LC50 value was 1.2%. The photo-Fenton treatment catalyzed with an iron-pillared clay reduced this parameter by 341.7%. Statistically significant increases with respect to the control group (PPCT, oxidative stress, genotoxic damage and LC50 in Hyalella azteca. PMID:27392336

  5. Solar photo-Fenton like using persulphate for carbamazepine removal from domestic wastewater

    OpenAIRE

    Ahmed, M M; Chiron, Serge

    2014-01-01

    This work aimed at decontaminating biologically treated domestic wastewater effluent from pharmaceutical residues by using sulphate radical based homogeneous photo-Fenton involving persulphate (PS) as an oxidant, ferrous iron (Fe(II)) as a catalyst and simulated solar irradiation as a light source. This is the first time that the beneficiary use of solar energy in PS/Fe(II)/UV-Vis system was evaluated by using carbamazepine (CBZ) as a probe compound. In wastewater, CBZ was fully degraded in 3...

  6. REMOVAL OF REMAZOL ROSSO RB DYE FROM AQUEOUS EFFLUENTS BY HOMOGENOUS FENTON OXIDATION PROCESSES

    OpenAIRE

    Carmen Zaharia; Victoria Fedorcea; Adrian Beda; Victor Amarandei; Augustin Muresan

    2014-01-01

    The paper presents some data from our laboratory-setup experiments of homogenous oxidative processes with hydrogen peroxide (i.e. advanced Fenton oxidation processes) applied for Remazol Rosso RB dye-containing aqueous systems, especially textile effluents. Therefore, some different operating parameters (including pH, concentration of dye, H2O2 and ferrous ions, oxidation time, temperature, stirring regime, among its) were tested for determination of the best performance in effluent decolorat...

  7. Combined treatment of retting flax wastewater using Fenton oxidation and granular activated carbon

    OpenAIRE

    Sohair I. Abou-Elela; Mohammed Eid M. Ali; Ibrahim, Hanan S.

    2016-01-01

    The process of retting flax produces a huge amount of wastewater which is characterized with bad unpleasant smell and high concentration of organic materials. Treatment of such waste had always been difficult because of the presence of refractory organic pollutants such as lignin. In this study, treatment of retting wastewater was carried out using combined system of Fenton oxidation process followed by adsorption on granular activated carbon (GAC). The effects of operating condition on Fento...

  8. Photo-Fenton and Slow Sand Filtration coupling for hydroponics water reuse

    OpenAIRE

    Micó Reche, Mª del Mar

    2013-01-01

    The collaboration between the University of Barcelona and Acciona Agua was focused on optimizing greenhouses hydric resources. The functionality of a combined treatment had to be assessed, when applied to the discard stream of a recycling system of the Advanced Greenhouse leachates. The coupling consisted on an Advanced Oxidation Processes (AOP), photo-Fenton, based on hydroxyl radical oxidative potential, produced by the interaction between Fe2+ and H2O2, and a slow sand filtration column ac...

  9. New approach to solar photo-Fenton operation. Raceway ponds as tertiary treatment technology

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Raceway ponds are used for the first time as photo-Fenton reactors. • Raceway ponds are effective and have high treatment capacity (48 mg/h m2 for 360 L). • The highest treatment capacity occurs with 5.5 mg Fe/L and 15 cm liquid depth. • Low iron concentrations are enough to oxidise the pesticide mixture. • Raceway ponds are a simple and low-cost alternative for micropollutant removal. - Abstract: The photo-Fenton process has proven its efficiency in the removal of micropollutants. However, the high costs usually associated with it prevent a spread of this technology. An important factor affecting costs is the kind of photoreactor used, usually tubular with a reflecting surface. Tubular reactors like compound parabolic collectors, CPCs, involve high capital costs. In comparison, the application of less costly reactors such as the extensive raceway ponds (RPRs) would help to spread the use of the photo-Fenton process as tertiary treatment at commercial scale. As far as the authors know, RPRs have never been used in advanced oxidation processes (AOPs) applications. This work is aimed at studying the applicability of RPRs to remove micropollutants with solar photo-Fenton. For this purpose, a pesticide mixture of commercial acetamiprid (ACTM) and thiabendazole (TBZ) (100 μg/L each) was used in simulated secondary effluent. Iron concentration (1, 5.5 and 10 mg/L) and liquid depth (5, 10 and 15 cm) were studied as process variables. TBZ was removed at the beginning of the treatment (less than 5 min), although ACTM removal times were longer (20–40 min for the highest iron concentrations). High treatment capacity per surface area was obtained (48 mg/h m2 with 5.5 mg Fe/L and 15 cm liquid depth), proving the feasibility of using RPRs for micropollutant removal

  10. New approach to solar photo-Fenton operation. Raceway ponds as tertiary treatment technology

    Energy Technology Data Exchange (ETDEWEB)

    Carra, Irene; Santos-Juanes, Lucas [Department of Chemical Engineering, University of Almería, 04120, Almería (Spain); CIESOL, Joint Centre of the University of Almería-CIEMAT, 04120, Almería (Spain); Acién Fernández, Francisco Gabriel [Department of Chemical Engineering, University of Almería, 04120, Almería (Spain); Malato, Sixto [CIESOL, Joint Centre of the University of Almería-CIEMAT, 04120, Almería (Spain); Plataforma Solar de Almería (CIEMAT), 04200, Tabernas, Almería (Spain); Sánchez Pérez, José Antonio, E-mail: jsanchez@ual.es [Department of Chemical Engineering, University of Almería, 04120, Almería (Spain); CIESOL, Joint Centre of the University of Almería-CIEMAT, 04120, Almería (Spain)

    2014-08-30

    Graphical abstract: - Highlights: • Raceway ponds are used for the first time as photo-Fenton reactors. • Raceway ponds are effective and have high treatment capacity (48 mg/h m{sup 2} for 360 L). • The highest treatment capacity occurs with 5.5 mg Fe/L and 15 cm liquid depth. • Low iron concentrations are enough to oxidise the pesticide mixture. • Raceway ponds are a simple and low-cost alternative for micropollutant removal. - Abstract: The photo-Fenton process has proven its efficiency in the removal of micropollutants. However, the high costs usually associated with it prevent a spread of this technology. An important factor affecting costs is the kind of photoreactor used, usually tubular with a reflecting surface. Tubular reactors like compound parabolic collectors, CPCs, involve high capital costs. In comparison, the application of less costly reactors such as the extensive raceway ponds (RPRs) would help to spread the use of the photo-Fenton process as tertiary treatment at commercial scale. As far as the authors know, RPRs have never been used in advanced oxidation processes (AOPs) applications. This work is aimed at studying the applicability of RPRs to remove micropollutants with solar photo-Fenton. For this purpose, a pesticide mixture of commercial acetamiprid (ACTM) and thiabendazole (TBZ) (100 μg/L each) was used in simulated secondary effluent. Iron concentration (1, 5.5 and 10 mg/L) and liquid depth (5, 10 and 15 cm) were studied as process variables. TBZ was removed at the beginning of the treatment (less than 5 min), although ACTM removal times were longer (20–40 min for the highest iron concentrations). High treatment capacity per surface area was obtained (48 mg/h m{sup 2} with 5.5 mg Fe/L and 15 cm liquid depth), proving the feasibility of using RPRs for micropollutant removal.

  11. A heterogeneous Fenton-like system with nanoparticulate zero-valent iron for removal of 4-chloro-3-methyl phenol

    International Nuclear Information System (INIS)

    The removal of biocide 4-chloro-3-methyl phenol (CMP) was investigated by heterogeneous Fenton-like system using nanoparticulate zero-valent iron (nZVI) as catalyst. The properties of nZVI before and after reaction were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The effects of pH value, initial concentration of CMP, nZVI dose and hydrogen peroxide (H2O2) concentration were determined. The experimental results showed that lower pH value and CMP concentration brought faster degradation rate. With the initial pH value of 6.1 and initial CMP concentration of 0.7 mM, the optimal dosage of reagents were 0.5 g nZVI/L and 3.0 mM H2O2. At pH 6.1, the degradation of CMP followed two-stage first-order kinetic that composed of an induction period (first-stage) and a followed rapid degradation stage (second-stage). According to the effects of scavengers n-butanol and KI, hydroxyl radicals (·OH), especially the surface-bounded ·OH, had a dominant role in the oxidation of CMP. The degradation intermediates, carboxylic acids and chloride ion produced during the reaction process were monitored by high performance liquid chromatography (HPLC), liquid chromatography/mass spectrometry (LC/MS) and ion chromatography (IC). On the basis of these findings, the possible mechanistic steps of CMP degradation were proposed.

  12. Treatment of landfill leachate using a combined stripping, Fenton, SBR, and coagulation process

    International Nuclear Information System (INIS)

    The leachate from Changshengqiao landfill (Chongqing, China) was characterized and submitted to a combined process of air stripping, Fenton, sequencing batch reactor (SBR), and coagulation. Optimum operating conditions for each process were identified. The performance of the treatment was assessed by monitoring the removal of organic matter (COD and BOD5) and ammonia nitrogen (NH3-N). It has been confirmed that air stripping (at pH 11.0 and aeration time 18 h) effectively removed 96.6% of the ammonia. The Fenton process was investigated under optimum conditions (pH 3.0, FeSO4.7H2O of 20 g l-1 and H2O2 of 20 ml l-1), COD removal of up to 60.8% was achieved. Biodegradability (BOD5/COD ratio) increased from 0.18 to 0.38. Thereafter the Fenton effluent was mixed with sewage at dilutions to a ratio of 1:3 before it was subjected to the SBR reactor; under the optimum aeration time of 20 h, up to 82.8% BOD5 removal and 83.1% COD removal were achieved. The optimum coagulant (Fe2(SO4)3) was a dosage of 800 mg l-1 at pH of 5.0, which reduced COD to an amount of 280 mg l-1. These combined processes were successfully employed and very effectively decreased pollutant loading.

  13. Disintegration and dissolution of spent radioactive cationic exchange resins using Fenton-like oxidation process

    Energy Technology Data Exchange (ETDEWEB)

    Wan, Zhong; Xu, Lejin [Collaborative Innovation Center for Advanced Nuclear Energy Technology, INET, Tsinghua University, Beijing 100084 (China); Wang, Jianlong, E-mail: wangjl@tsinghua.edu.cn [Collaborative Innovation Center for Advanced Nuclear Energy Technology, INET, Tsinghua University, Beijing 100084 (China); Beijing Key Laboratory of Radioactive Wastes Treatment, Tsinghua University, Beijing 100084 (China)

    2015-09-15

    Highlights: • The spent radioactive resins could be oxidized by Fenton-like process. • The influencing factors on resin oxidation were evaluated. • Chemical oxygen demand (COD) reduction rate was more than 99%. • SEM and Raman spectrum were used to analyze the resins morphological change. - Abstract: The treatment and disposal of the spent radioactive resins is essential for the sustainable development of the nuclear industry. In this paper, the disintegration and dissolution of spent cationic resins were studied by Fenton-like process. The influencing factors on resin dissolution, such as pH, temperature, type and concentration of catalysts were evaluated. The results showed that the spent resins could be effectively dissolved at pH < 1, [Fe{sup 2+}] = 0.2 M and T = 97 ± 2 °C. Chemical oxygen demand (COD) reduction rate was more than 99%. The scanning electron microscopy and the Raman spectrum were used to observe the morphological changes of the spent resins during the dissolution process. Fenton-like oxidation is an efficient method for the volume reduction and stabilization of the spent resins before further immobilization.

  14. Photo-fenton process: Optimization and decolourization and mineralization of reactive blue 222 dye

    Directory of Open Access Journals (Sweden)

    Shumaila Kiran

    2012-12-01

    Full Text Available Dye house effluents of textile industries leads to severe environmental problems when disposed to aquatic bodies without proper treatment. This work was carried out to optimize the Photo-Fenton process for decolorization and mineralization of a commercial textile dye, Reactive Blue 222. The effect of different process parameters on decolorization efficiency of Photo-Fenton process was investigated. The optimal conditions for process were observed as; pH level 3.5, H2O2 concentration 1× 10-2M, FeSO4 concentration 3.5 × 10-5 mol L-1, temperature 50˚C and process time 50 min. The maximum 95% dye decolorization was achieved along with a significant (P< 0.05 reduction of chemical oxygen demand and total organic. The degradation products were characterized by UV–visible and FTIR spectral techniques. The results provide evidence that Photo-Fenton process was able to oxidize and mineralize the selected azo dye into non-toxic metabolites.

  15. Photoassisted fenton oxidation of refractory organics in UASB-pretreated leachate

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Nearly 91% of organic pollutants in Hong Kong leachate could be effectively removed by the UASB (upflow anaerobic sludge blanket) process followed by the fenton coagulation.The COD (chemical oxygen demand) of leachate was lowered from an average of 5620 mg/L to 1910 mg/L after the UASB treatment at 37C,and was further lowered to 513 mg/L after fenton coagulation.The remaining refractory residues could be further removed by photochemical oxidation with the addition of H202 .The BOD/COD ratio was greatly increased from 0.062 to 0.142,indicating the biodegradability of organic residues was improved.The photochemical oxidation for the fenton-ceagulation supernatant was most effective at pH 3-4,with the addition of 800 mg/L of H202,and UV radiation time of 30 minutes.The final effluent contained only 148 mg/L of COD,21 mg/L of BOD(biochemieal oxygen demand) and 56 mg/L of TOC (total organic carbon).

  16. Disintegration and dissolution of spent radioactive cationic exchange resins using Fenton-like oxidation process

    International Nuclear Information System (INIS)

    Highlights: • The spent radioactive resins could be oxidized by Fenton-like process. • The influencing factors on resin oxidation were evaluated. • Chemical oxygen demand (COD) reduction rate was more than 99%. • SEM and Raman spectrum were used to analyze the resins morphological change. - Abstract: The treatment and disposal of the spent radioactive resins is essential for the sustainable development of the nuclear industry. In this paper, the disintegration and dissolution of spent cationic resins were studied by Fenton-like process. The influencing factors on resin dissolution, such as pH, temperature, type and concentration of catalysts were evaluated. The results showed that the spent resins could be effectively dissolved at pH < 1, [Fe2+] = 0.2 M and T = 97 ± 2 °C. Chemical oxygen demand (COD) reduction rate was more than 99%. The scanning electron microscopy and the Raman spectrum were used to observe the morphological changes of the spent resins during the dissolution process. Fenton-like oxidation is an efficient method for the volume reduction and stabilization of the spent resins before further immobilization

  17. Soil remediation using a coupled process: soil washing with surfactant followed by photo-Fenton oxidation

    International Nuclear Information System (INIS)

    In the present work the use of a coupled process, soil washing and photo-Fenton oxidation, was investigated for remediation of a soil contaminated with p,p'-DDT (DDT) and p,p'-DDE (DDE), and a soil artificially contaminated with diesel. In the soil washing experiments, Triton X-100 (TX-100) aqueous solutions were used at different concentrations to obtain wastewaters with different compositions. Removal efficiencies of 66% (DDT), 80% (DDE) and 100% (diesel) were achieved for three sequential washings using a TX-100 solution strength equivalent to 12 times the effective critical micelle concentration of the surfactant (12 CMCeff). The wastewater obtained was then treated using a solar photo-Fenton process. After 6 h irradiation, 99, 95 and 100% degradation efficiencies were achieved for DDT, DDE and diesel, respectively. In all experiments, the concentration of dissolved organic carbon decreased by at least 95%, indicating that residual concentration of contaminants and/or TX-100 in the wastewater was very low. The co-extraction of metals was also evaluated. Among the metals analyzed (Pb, Cr, Ni, Cu, Cd, Mn and Co), only Cr and Mn were detected in the wastewater at concentrations above the maximum value permitted by current Brazilian legislation. The effective removal of contaminants from soil by the TX-100 washing process, together with the high degradation efficiency of the solar photo-Fenton process, suggests that this procedure could be a useful option for soil remediation.

  18. Repeated oxidative degradation of methyl orange through bio-electro-Fenton in bioelectrochemical system (BES).

    Science.gov (United States)

    Ling, Ting; Huang, Bin; Zhao, Mingxing; Yan, Qun; Shen, Wei

    2016-03-01

    Composite Fe2O3/ACF electrode facilitated methyl orange (MO) oxidative degradation using bio-electro-Fenton in bioelectrochemical system (BES) was investigated. Characterized by both XPS and FT-IR techniques, it was found that the composite Fe2O3/ACF electrode with highest Fe loading capacity of 11.02% could be prepared after the carbon felt was oxidized with nitric acid. Moreover, hydrogen peroxide production reached steadily at 88.63 μmol/L with the external resistance as 100 Ω, cathodic aeration rate at 750 mL/min, and the pH of the bio-electro-Fenton system adjusted to 2. Significantly, not only the electrochemical profiles of the BES reactor as electrochemical impedance spectroscopy (EIS) was bettered, but the MO oxidative degradation could be accomplished for eight repeated batches, with the MO removal efficiency varied slightly from 73.9% to 86.7%. It indicated that the bio-electro-Fenton might be a promising eco-friendly AOP method for Azo-dye wastewater treatment. PMID:26722807

  19. Methyl-orange and cadmium simultaneous removal using fly ash and photo-Fenton systems

    Energy Technology Data Exchange (ETDEWEB)

    Visa, Maria, E-mail: visamro2000@yahoo.com [Transilvania University of Brasov, Department of Renewable Energy Systems and Recycling, Eroilor 29, 500036 Brasov (Romania); Duta, Anca, E-mail: a.duta@unitbv.ro [Transilvania University of Brasov, Department of Renewable Energy Systems and Recycling, Eroilor 29, 500036 Brasov (Romania)

    2013-01-15

    Highlights: ► The mixed substrates of FA-M + TiO{sub 2} proved to be highly efficient in adsorption. ► FA-M + photo-Fenton are a low-cost material for advanced treatment of wastewater. ► The adsorbed MO may act as a complexion agent, increasing the affinity for metals. ► Dye removal by photodegradation is the favourable mechanism compared to adsorption. -- Abstract: Wastewaters resulting from the textile and dye finishing industries need complex treatment for efficient removal of colour and other compounds existent in the dyeing and rising baths (heavy metals, surfactants, equalizers, etc.). Modified fly ash (FA) mixed with TiO{sub 2} photocatalyst represent a viable option for simultaneous removal of dyes and heavy metals, and the optimized conditions are discussed in this paper for synthetic wastewaters containing methyl-orange (MO) and cadmium. For a cost-effective dye removal process, further tests were done, replacing the photocatalyst with a (photo)Fenton system. The optimized technological parameters (contact time, amount of fly ash and amount of Fe{sup 2+}/H{sub 2}O{sub 2}) allow to reach removal efficiencies up to 88% for the heavy metal and up to 70% for the dye. The adsorption mechanisms and the process kinetic are discussed, also considering the possibility of in situ generation of the Fenton system, due to the fly ash composition.

  20. Methyl-orange and cadmium simultaneous removal using fly ash and photo-Fenton systems

    International Nuclear Information System (INIS)

    Highlights: ► The mixed substrates of FA-M + TiO2 proved to be highly efficient in adsorption. ► FA-M + photo-Fenton are a low-cost material for advanced treatment of wastewater. ► The adsorbed MO may act as a complexion agent, increasing the affinity for metals. ► Dye removal by photodegradation is the favourable mechanism compared to adsorption. -- Abstract: Wastewaters resulting from the textile and dye finishing industries need complex treatment for efficient removal of colour and other compounds existent in the dyeing and rising baths (heavy metals, surfactants, equalizers, etc.). Modified fly ash (FA) mixed with TiO2 photocatalyst represent a viable option for simultaneous removal of dyes and heavy metals, and the optimized conditions are discussed in this paper for synthetic wastewaters containing methyl-orange (MO) and cadmium. For a cost-effective dye removal process, further tests were done, replacing the photocatalyst with a (photo)Fenton system. The optimized technological parameters (contact time, amount of fly ash and amount of Fe2+/H2O2) allow to reach removal efficiencies up to 88% for the heavy metal and up to 70% for the dye. The adsorption mechanisms and the process kinetic are discussed, also considering the possibility of in situ generation of the Fenton system, due to the fly ash composition

  1. New approach to solar photo-Fenton operation. Raceway ponds as tertiary treatment technology.

    Science.gov (United States)

    Carra, Irene; Santos-Juanes, Lucas; Acién Fernández, Francisco Gabriel; Malato, Sixto; Sánchez Pérez, José Antonio

    2014-08-30

    The photo-Fenton process has proven its efficiency in the removal of micropollutants. However, the high costs usually associated with it prevent a spread of this technology. An important factor affecting costs is the kind of photoreactor used, usually tubular with a reflecting surface. Tubular reactors like compound parabolic collectors, CPCs, involve high capital costs. In comparison, the application of less costly reactors such as the extensive raceway ponds (RPRs) would help to spread the use of the photo-Fenton process as tertiary treatment at commercial scale. As far as the authors know, RPRs have never been used in advanced oxidation processes (AOPs) applications. This work is aimed at studying the applicability of RPRs to remove micropollutants with solar photo-Fenton. For this purpose, a pesticide mixture of commercial acetamiprid (ACTM) and thiabendazole (TBZ) (100μg/L each) was used in simulated secondary effluent. Iron concentration (1, 5.5 and 10mg/L) and liquid depth (5, 10 and 15cm) were studied as process variables. TBZ was removed at the beginning of the treatment (less than 5min), although ACTM removal times were longer (20-40min for the highest iron concentrations). High treatment capacity per surface area was obtained (48mg/hm(2) with 5.5mg Fe/L and 15cm liquid depth), proving the feasibility of using RPRs for micropollutant removal. PMID:25072137

  2. An insight in magnetic field enhanced zero-valent iron/H2O2 Fenton-like systems: Critical role and evolution of the pristine iron oxides layer

    Science.gov (United States)

    Xiang, Wei; Zhang, Beiping; Zhou, Tao; Wu, Xiaohui; Mao, Juan

    2016-04-01

    This study demonstrated the synergistic degradation of 4-chlorophenol (4-CP) achieved in a magnetic field (MF) enhanced zero-valent iron (ZVI)/H2O2 Fenton-like (FL) system and revealed an interesting correlative dependence relationship between MF and the pristine iron oxides layer (FexOy) on ZVI particles. First, a comparative investigation between the FL and MF-FL systems was conducted under different experimental conditions. The MF-FL system could suppress the duration of initial lag degradation phase one order of magnitude in addition of the significant enhancement in overall 4-CP degradation. Monitoring of intermediates/products indicated that MF would just accelerate the Fenton reactions to produce hydroxyl radical more rapidly. Evolutions of simultaneously released dissolved iron species suggested that MF would not only improve mass-transfer of the initial heterogeneous reactions, but also modify the pristine ZVI surface. Characterizations of the specific prepared ZVI samples evidenced that MF would induce a special evolution mechanism of the ZVI particles surface depending on the existence of FexOy layer. It comprised of an initial rapid point dissolution of FexOy and a following pitting corrosion of the exposed Fe0 reactive sites, finally leading to appearance of a particular rugged surface topography with numerous adjacent Fe0 pits and FexOy tubercles.

  3. Efficient conversion of dimethylarsinate into arsenic and its simultaneous adsorption removal over FeCx/N-doped carbon fiber composite in an electro-Fenton process.

    Science.gov (United States)

    Lan, Huachun; Li, Jianfei; Sun, Meng; An, Xiaoqiang; Hu, Chengzhi; Liu, Ruiping; Liu, Huijuan; Qu, Jiuhui

    2016-09-01

    In this study, a FeCx/N-doped carbon fiber composite (FeCx/NCNFs) was developed via an electrospinning method. According to the characterization results of XRD, TEM and XPS, FeCx (a mixture of Fe7C3 and Fe3C) was either embedded in or attached to the NCNFs. It was used for the first time as a catalyst for dimethylarsinate (DMA) degradation and as an absorbent for inorganic arsenic (As (V)), with degradation and adsorption occurring simultaneously, in an electro-Fenton process. The effects of catalyst dosage, initial DMA concentration, solution pH, and applied current on the treatment efficiency and the corresponding H2O2 generation were systematically investigated. The results showed that DMA could be efficiently oxidized into As(V). 96% of DMA was degraded after reaction time of 360 min and the residual As(V) concentration in solution was below the allowable limit of 0.01 mg/L under the optimum treatment conditions. Based on an ESR and radical scavenger experiment, OH was proven to be the sole reactive oxygen species involved in the degradation process of DMA. DMA was oxidized to MMA as the primary oxidation product, which was subsequently oxidized to inorganic arsenic, As (V). TOC was also efficiently removed at the same time. The DMA removal mechanism for simultaneous degradation of dimethylarsinate and adsorption of arsenic over FeCx/NCNFs in the electro-Fenton process was also proposed based on the experimental results. PMID:27179339

  4. Effect of iron salt counter ion in dose-response curves for inactivation of Fusarium solani in water through solar driven Fenton-like processes

    Science.gov (United States)

    Aurioles-López, Verónica; Polo-López, M. Inmaculada; Fernández-Ibáñez, Pilar; López-Malo, Aurelio; Bandala, Erick R.

    2016-02-01

    The inactivation of Fusarium solani in water was assessed by solar driven Fenton-like processes using three different iron salts: ferric acetylacetonate (Fe(acac)3), ferric chloride (FeCl3) and ferrous sulfate (FeSO4). The experimental conditions tested were [Fe] ≈ 5 mg L-1, [H2O2] ≈ 10 mg L-1 and [Fe] ≈ 10 mg L-1; [H2O2] ≈ 20 mg L-1 mild and high, respectively, and pH 3.0 and 5.0, under solar radiation. The highest inactivation rates were observed at high reaction conditions for the three iron salts tested at pH 5.0 with less than 3.0 kJ L-1 of accumulate energy (QUV) to achieve over 99.9% of F. solani inactivation. Fe(acac)3 was the best iron salt to accomplishing F. solani inactivation. The modified Fermi equation was used to fix the experimental inactivation, data showed it was helpful for modeling the process, adequately describing dose-response curves. Inactivation process using FeSO4 at pH 3.0 was modeled fairly with r2 = 0.98 and 0.99 (mild and high concentration, respectively). Fe(acac)3, FeCl3 and FeSO4 at high concentration (i.e. [Fe] ≈ 10 mg L-1; [H2O2] ≈ 20 mg L-1) and pH 5.0 showed the highest fitting values (r2 = 0.99). Iron salt type showed a remarkable influence on the Fenton-like inactivation process.

  5. Destruction of Ion-Exchange Resin In Waste From the HFIR, T1 and T2 Tanks Using Fenton's Reagent

    International Nuclear Information System (INIS)

    The use of Fenton's reagent (hydrogen peroxide and a ferrous iron catalyst) has been tested as a method for destroying ion-exchange resin in radioactive waste from three underground storage tanks at the Oak Ridge National Laboratory. The resin in these wastes must be destroyed before they can be transferred to the Melton Valley Storage Tanks (MVSTs) prior to solidification and disposal at the Waste Isolation Pilot Plant. The reaction with ion-exchange resin requires a dilute acidic solution (pH = 3 to 5) and moderate temperatures (T = 60 to 100 C). Laboratory-scale tests of the process have been successfully completed using both simulants and actual waste samples. The ion-exchange resin is oxidized to carbon dioxide and inorganic salts. The reaction rate is quite slow for temperatures below 70 C but increases almost linearly as the temperature of the slurry increases from 70 to 90 C. Pilot-scale tests have demonstrated the process using larger samples of actual waste slurries. A sample from the High Flux Isotope Reactor (HFIR) tank, containing 500 mL of settled solids (resin and inorganic sludge) in a total volume of 1800 mL, was successfully treated to meet MVST waste acceptance requirements in 9 h of processing time, using 1650 mL of 50 wt% hydrogen peroxide. A composite sample from the T1 and T2 tanks, which contained 1000 mL of settled solids in a total volume of 2000 mL required 8 h of treatment, using 1540 mL of 50 wt% peroxide, to meet waste acceptance requirements. Hydrogen peroxide reaction rates were 0.71 to 0.74 g H2O2/L/min, with very low (<2000 mg/L) concentrations of peroxide in the slurry. The reaction produces mostly carbon dioxide gas during the early part of the treatment, when organic carbon concentrations in the slurry are high, and then produces increasing amounts of oxygen as the organic carbon concentration drops. Small amounts (<3 vol%) of carbon monoxide are also generated. The off-gas from the pilot-scale tests, which was 81 vol% nitrogen

  6. Fenton oxidation to remediate PAHs in contaminated soils: A critical review of major limitations and counter-strategies.

    Science.gov (United States)

    Usman, M; Hanna, K; Haderlein, S

    2016-11-01

    Fenton oxidation constitutes a viable remediation strategy to remove polycyclic aromatic hydrocarbons (PAHs) in contaminated soils. This review is intended to illustrate major limitations associated with this process like acidification, PAH unavailability, and deterioration of soil quality along with associated factors, followed by a critical description of various developments to overcome these constraints. Considering the limitation that its optimal pH is around 3, traditional Fenton treatment could be costly, impractical in soil due to the high buffering capacity of soils and associated hazardous effects. Use of various chelating agents (organic or inorganic) allowed oxidation at circumneutral pH but factors like higher oxidant demand, cost and toxicity should be considered. Another alternative is the use of iron minerals that can catalyze Fenton-like oxidation over a wide range of pH, but mobility of these particles in soils (i.e. saturated and unsaturated zones) should be investigated prior to in-situ applications. The PAH-unavailability is the crucial limitation hindering their effective degradation. Research data is compiled describing various strategies to address this issue like the use of availability enhancement agents, extraction or thermal pretreatment. Last section of this review is devoted to describe the effects of various developments in Fenton treatment onto soil quality and native microbiota. Finally, research gaps are discussed to suggest future directions in context of applying Fenton oxidation to remediate contaminated soils. PMID:27341118

  7. Decolorization of distillery spent wash effluent by electro oxidation (EC and EF) and Fenton processes: A comparative study.

    Science.gov (United States)

    David, Charles; Arivazhagan, M; Tuvakara, Fazaludeen

    2015-11-01

    In this study, laboratory scale experiments were performed to degrade highly concentrated organic matter in the form of color in the distillery spent wash through batch oxidative methods such as electrocoagulation (EC), electrofenton (EF) and Fenton process. The effect of corresponding operating parameters, namely initial pH: 2-10; current intensity: 1-5A; electrolysis time: 0.5-4h; agitation speed: 100-500rpm; inter-electrode distance: 0.5-4cm and Fenton's reagent dosage: 5-40mg/L was employed for optimizing the process of spent wash color removal. The performance of all the three processes was compared and assessed in terms of percentage color removal. For EC, 79% color removal was achieved using iron electrodes arranged with 0.5cm of inter-electrode space and at optimum conditions of pH 7, 5A current intensity, 300rpm agitation speed and in 2h of electrolysis time. In EF, 44% spent wash decolorization was observed using carbon (graphite) electrodes with an optimum conditions of 0.5cm inter-electrode distance, pH 3, 4A current intensity, 20mg/L FeSO4 and agitation speed of 400rpm for 3h of electrolysis time. By Fenton process, 66% decolorization was attained by Fenton process at optimized conditions of pH 3, 40mg/L of Fenton's reagent and at 500rpm of agitation speed for 4h of treatment time. PMID:25952698

  8. Study on the advanced treatment of synthesis pharmaceutical wastewater by fluidized bed fenton%流体化床Fenton深度处理合成制药废水研究

    Institute of Scientific and Technical Information of China (English)

    王付超; 梅荣武; 刘俊

    2012-01-01

    The fluidized-bed Fenton reactor was employed for advanced treatment of synthesis pharmaceutical wastewater.Through orthogonal tests,the best reaction conditions for synthesis pharmaceutical wastewater treatment were determined as 20 min of HRT,4.0 of initial pH value,4.0 of H2O2/CODcr mass ratio and 15 of H2O2/Fe2+ Moore ratio.Under those optimum conditions,CODcr concentration of the effluent was detected stably below 80 mg/L,which complies with the Class A of Integrated Wastewater Discharge Standard(GB8978-1996).Comparing to the standard Fenton oxidation,the application of fluidized-bed Fenton reactor resulted in an improvement of over 13% on CODcr removal efficiency,as well as a reduction of 70% on sludge yield.Accordingly,the operating costs can be reduced by 28%,which could be controlled within 3.0 yuan/tons wastewater in stable conditions.%采用流体化床Fenton装置深度处理合成制药废水,通过正交试验确定了处理合成制药废水的最佳条件是HRT为20min,初始pH值为4.0,H2O2/CODcr(质量比)为4.0,H2O2/Fe2+(摩尔比)为15,且在最佳条件下出水CODcr稳定在80mg/L以下,可以达到《污水综合排放标准》(GB8979-1996)一级标准。同时将其与标准Fenton氧化法进行对比试验,结果显示流体化床FentonCODcr去除率可提高13%以上,污泥产生量可降低70%,运行成本可减低28%,稳定运行成本可以控制在3.0元/吨废水以内。

  9. Chemically modified graphite felt as an efficient cathode in electro-Fenton for p-nitrophenol degradation

    International Nuclear Information System (INIS)

    Highlights: • Chemically modified graphite felt was prepared using ethanol and hydrazine hydrate as reagents. • Carbon nanoparticles with functional groups were deposited on the surface after modification. • The electrochemical activity for ORR and H2O2 generation on the modified electrode was improved. • The cathode modification effictively improved the EF performance for pollutant degradation. - Abstract: A simple method with low-cost chemical reagents ethanol and hydrazine hydrate was used to modify graphite felt as the cathode for electro-Fenton (EF) application, using p-nitrophenol (p-Np) as the model pollutant. Characterized by scanning electron microscope, contact angle, Raman spectrum and X-ray photoelectron spectroscopy, the morphology and surface physicochemical properties after modification were observed considerably changed. After modification, some nanoparticles and oxygen and nitrogen-containing functional groups appeared on the cathode surface, which greatly improved the surface hydrophilic property and the electrocatalytic activity for oxygen reduction reaction. The effects led to the hydrogen peroxide accumulation on the modified cathode markedly increased to 175.8 mg L−1, while that on the unmodified one was only 67.5 mg L−1. p-Np of initial 50 mg L−1 could be completely removed by EF using the modified cathode, and the mineralization ratio reached 51.4%, more than 2 times of the pristine one. After 10 cycles, the mineralization ratio of the modified cathode was still above 45%, suggesting that the modification method can provide an effective approach to improve EF performance, and thus benefits to promote its environmental applications

  10. DETERMINACIÓN DE LA DOSIS ÓPTIMA DE REACTIVO FENTON EN UN TRATAMIENTO DE LIXIVIADOS POR FENTON-ADSORCIÓN

    OpenAIRE

    Roger Iván MÉNDEZ NOVELO; José Alfredo PIETROGIOVANNA BRONCA; Beatriz SANTOS OCAMPO; María Rosa SAURI RIANCHO; Germán GIÁCOMAN VALLEJOS; Elba René CASTILLO BORGES

    2010-01-01

    Los lixiviados son el resultado de la percolación de líquidos a través de los desechos sólidos en proceso de estabilización. La complejidad de su tratamiento se debe a que su composición es altamente tóxica y variable. Lo anterior y el suelo altamente permeable de la península de Yucatán, representan un alto peligro a la salud. Se ensayó un tratamiento de oxidación tipo Fenton-adsorción con el que se obtuvieron mejores resultados que con otros tratamientos fisicoquímicos o biológicos reportad...

  11. Stabilization and dewatering of wastewater treatment plants sludge using the Fenton process

    Directory of Open Access Journals (Sweden)

    Abolfazl Azhdarpoor

    2015-11-01

    Full Text Available Wastewater sludge typically contains large amounts of water and organic materials; therefore, its stabilization and dewatering is of particular importance. In this study, Fenton oxidation process is used for stabilization and dewatering of sludge in the output of a wastewater treatment plant. To evaluate the sludge stabilization and dewatering, specific resistance to filtration (SRF, volatile organic compounds (VSS, total suspended solids (TSS, soluble chemical oxygen demand (SCOD and heterotrophic bacteria were measured. During the experiment, the optimal values of various parameters such as pH (2-9, hydrogen peroxide (0.015- 0.18mol/L, Fe2+ (0.008- 0.1mol/L and time (5 - 60 minutes for optimum sludge dewatering and stabilization were investigated. The results showed that the highest percentages of SRF reduction and removal rates of SCOD, VSS and TSS were 99.48, 61, 42, and 41 percent respectively. These results were obtained in optimum pH 5, 0.05 mol/l Fe2+, 0.12 mol/l hydrogen peroxide, and the retention time of 15 minutes. The removal rate of heterotrophic bacteria increased with increasing dose of hydrogen peroxide, so that a removal rate of 84 percent was observed at a dose of 0.18 mol/l. In general, Fenton process can reduce volatile organic materials and chemical oxygen demand of the sludge resulting in its significant stabilization and dewatering. In general, Fenton process can reduce volatile organic materials and chemical oxygen demand of the sludge resulting in its significant stabilization and dewatering.

  12. REMOVAL OF REMAZOL ROSSO RB DYE FROM AQUEOUS EFFLUENTS BY HOMOGENOUS FENTON OXIDATION PROCESSES

    Directory of Open Access Journals (Sweden)

    Carmen Zaharia

    2014-06-01

    Full Text Available The paper presents some data from our laboratory-setup experiments of homogenous oxidative processes with hydrogen peroxide (i.e. advanced Fenton oxidation processes applied for Remazol Rosso RB dye-containing aqueous systems, especially textile effluents. Therefore, some different operating parameters (including pH, concentration of dye, H2O2 and ferrous ions, oxidation time, temperature, stirring regime, among its were tested for determination of the best performance in effluent decoloration and dye removal, meaning the optimal values of each studied parameters for highest decoloration or dye removal.

  13. Treatment of Actual Chemical Wastewater by a Heterogeneous Fenton Process Using Natural Pyrite

    OpenAIRE

    Liang Sun; Yan Li; Aimin Li

    2015-01-01

    Wastewater from chemical plants has remarkable antibiotic effects on the microorganisms in traditional biological treatment processes. An enhanced Fenton system catalyzed by natural pyrite was developed to degrade this kind of wastewater. Approximately 30% chemical oxygen demand (COD) was removed within 120 min when 50 mmol/L H2O2 and 10 g/L natural pyrite were used at initial pH from 1.8 to 7. A BOD5/COD enhancement efficiency of 210% and an acute biotoxicity removal efficiency of 84% were a...

  14. Evaluation of Fenton's Reagent and Activated Persulfate for Treatment of a Pharmaceutical Waste Mixture in Groundwater

    DEFF Research Database (Denmark)

    Bennedsen, Lars Rønn; Søgaard, Erik Gydesen; Kakarla, Prasad;

    2010-01-01

    , cyanide, chromium and other metals both within the aqueous and vapour phases. Except the alkaline activation, all the investigated techniques for activating persulfate were able to remove more than 80% of the primary contaminants. Optimization and more dosages led to 98-99% destruction of primary...... technology or series of technologies for a future full-scale remediation system. The bench tests investigated oxidant stability, oxidation efficiency, toxicity reduction, metal mobilization and, for the persulfate, different activating agents, including NaOH, chelated iron, and modified Fenton's reagent. 126...

  15. Treatment of pesticide wastewater by moving-bed biofilm reactor combined with Fenton-coagulation pretreatment

    International Nuclear Information System (INIS)

    In order to treat pesticide wastewater having high chemical oxygen demand (COD) value and poor biodegradability, Fenton-coagulation process was first used to reduce COD and improve biodegradability and then was followed by biological treatment. Optimal experimental conditions for the Fenton process were determined to be Fe2+ concentration of 40 mmol/L and H2O2 dose of 97 mmol/L at initial pH 3. The interaction mechanism of organophosphorous pesticide and hydroxyl radicals was suggested to be the breakage of the P=S double bond and formation of sulfate ions and various organic intermediates, followed by formation of phosphate and consequent oxidation of intermediates. For the subsequent biological treatment, 3.2 g/L Ca(OH)2 was added to adjust the pH and further coagulate the pollutants. The COD value could be evidently decreased from 33,700 to 9300 mg/L and the ratio of biological oxygen demand (BOD5) to COD of the wastewater was enhanced to over 0.47 by Fenton oxidation and coagulation. The pre-treated wastewater was then subjected to biological oxidation by using moving-bed biofilm reactor (MBBR) inside which tube chip type bio-carriers were fluidized upon air bubbling. Higher than 85% of COD removal efficiency could be achieved when the bio-carrier volume fraction was kept more than 20% by feeding the pretreated wastewater containing 3000 mg/L of inlet COD at one day of hydraulic retention time (HRT), but a noticeable decrease in the COD removal efficiency when the carrier volume was decreased down to 10%, only 72% was observed. With the improvement of biodegradability by using Fenton pretreatment, also due to the high concentration of biomass and high biofilm activity using the fluidizing bio-carriers, high removal efficiency and stable operation could be achieved in the biological process even at a high COD loading of 37.5 gCOD/(m2 carrier day)

  16. Cold Incineration of Chlorophenols in Aqueous Solution by Advanced Electrochemical Process Electro-Fenton. Effect of Number and Position of Chlorine Atoms on the Degradation Kinetics

    Science.gov (United States)

    Oturan, Nihal; Panizza, Marco; Oturan, Mehmet A.

    2009-09-01

    This study reports the kinetics of the degradation of several chlorophenols (CPs), such as monochlorophenols (2-chlorophenol and 4-chlorophenol), dichlorophenols (2,4-dichlorophenol and 2,6- dichlorophenol), trichlorophenols (2,3,5- trichlorophenol and 2,4,5-trichlorophenol), 2,3,5,6-tetrachlorophenol, and pentachlorophenol, by the electro-Fenton process using a carbon felt cathode and a Pt anode. The effect of number and the position of the chlorine atoms in the aromatic ring on the oxidative degradation rate was evaluated and discussed. The oxidation reaction of all the CPs with hydroxyl radicals evidenced a pseudo-first-order kinetics and the rate constant decreased with increasing the number of chlorine atoms. The absolute rate constant of second-order reaction kinetics between CPs and •OH was determined by the competition kinetics method in the range of (3.56-7.75) × 109 M-1 s-1 and follows the same sequence of the apparent rate constants. The mineralization of several CPs and of a mixture of all CPs under study was monitored by the total organic carbon (TOC) removal and the chlorine release during mineralization was followed by ion chromatography. Our results demonstrated that more chlorinated phenols are more difficult to mineralize; however for all the tested CPs, almost quantitative release of chloride ions was obtained after 6 h of treatment.

  17. Fenton process-affected transformation of roxarsone in paddy rice soils: Effects on plant growth and arsenic accumulation in rice grain.

    Science.gov (United States)

    Qin, Junhao; Li, Huashou; Lin, Chuxia

    2016-08-01

    Batch and greenhouse experiments were conducted to examine the effects of Fenton process on transformation of roxarsone in soils and its resulting impacts on the growth of and As uptake by a rice plant cultivar. The results show that addition of Fenton reagent markedly accelerated the degradation of roxarsone and produced arsenite, which was otherwise absent in the soil without added Fenton reagent. Methylation of arsenate was also enhanced by Fenton process in the earlier part of the experiment due to abundant supply of arsenate from Roxarsone degradation. Overall, addition of Fenton reagent resulted in the predominant presence of arsenate in the soils. Fenton process significantly improved the growth of rice in the maturity stage of the first crop, The concentration of methylated As species in the rice plant tissues among the different growth stages was highly variable. Addition of Fenton reagent into the soils led to reduced uptake of soil-borne As by the rice plants and this had a significant effect on reducing the accumulation of As in rice grains. The findings have implications for understanding As biogeochemistry in paddy rice field receiving rainwater-borne H2O2 and for development of mitigation strategies to reduce accumulation of As in rice grains. PMID:27060198

  18. Pretreatment of 2,4-dinitroanisole (DNAN) producing wastewater using a combined zero-valent iron (ZVI) reduction and Fenton oxidation process

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Jinyou, E-mail: shenjinyou-1981@163.com [Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, Jiangsu Province (China); Ou, Changjin; Zhou, Zongyuan [Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, Jiangsu Province (China); Chen, Jun; Fang, Kexiong [Hubei Dongfang Chemical Co. Ltd., Hubei 441404 (China); Sun, Xiuyun; Li, Jiansheng [Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, Jiangsu Province (China); Zhou, Lin [School of Mechatronical Engineering, Beijing Institute of Technology, Beijing 100081 (China); Wang, Lianjun, E-mail: wanglj@mail.njust.edu.cn [Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, Jiangsu Province (China)

    2013-09-15

    Highlights: • ZVI-Fenton process was conducted for DNAN producing wastewater pretreatment. • Transformation of nitro to amino group by ZVI overcomes the oxidative hindrance. • Subsequent Fenton process is efficient for the removal of aromatic compounds. • ABR-MBBR process is efficient for the polishing of ZVI-Fenton effluent. -- Abstract: A combined zero-valent iron (ZVI) reduction and Fenton oxidation process was tested for the pretreatment of 2,4-dinitroanisole (DNAN) producing wastewater. Operating conditions were optimized and overall performance of the combined process was evaluated. For ZVI process, almost complete reduction of nitroaromatic compounds was observed at empty bed contact time (EBCT) of 8 h. For Fenton process, the optimal pH, H{sub 2}O{sub 2} to Fe(II) molar ratio, H{sub 2}O{sub 2} dosage and hydraulic retention time (HRT) were found to be 3.0, 15, 0.216 mol/L and 5 h, respectively. After pretreatment by the combined ZVI-Fenton process under the optimal conditions, aromatic organic compound removal was as high as 77.2%, while the majority of COD remained to be further treated by sequent biological process. The combined anaerobic-aerobic process consisted of an anaerobic baffled reactor (ABR) and a moving-bed biofilm reactor (MBBR) was operated for 3 months, fed with ZVI-Fenton effluent. The results revealed that the coupled ZVI-Fenton-ABR-MBBR system was significantly efficient in terms of correcting the effluent's main parameters of relevance, mainly aromatic compounds concentration, COD concentration, color and acute toxicity. These results indicate that the combined ZVI-Fenton process offers bright prospects for the pretreatment of wastewater containing nitroaromatic compounds.

  19. Pretreatment of 2,4-dinitroanisole (DNAN) producing wastewater using a combined zero-valent iron (ZVI) reduction and Fenton oxidation process

    International Nuclear Information System (INIS)

    Highlights: • ZVI-Fenton process was conducted for DNAN producing wastewater pretreatment. • Transformation of nitro to amino group by ZVI overcomes the oxidative hindrance. • Subsequent Fenton process is efficient for the removal of aromatic compounds. • ABR-MBBR process is efficient for the polishing of ZVI-Fenton effluent. -- Abstract: A combined zero-valent iron (ZVI) reduction and Fenton oxidation process was tested for the pretreatment of 2,4-dinitroanisole (DNAN) producing wastewater. Operating conditions were optimized and overall performance of the combined process was evaluated. For ZVI process, almost complete reduction of nitroaromatic compounds was observed at empty bed contact time (EBCT) of 8 h. For Fenton process, the optimal pH, H2O2 to Fe(II) molar ratio, H2O2 dosage and hydraulic retention time (HRT) were found to be 3.0, 15, 0.216 mol/L and 5 h, respectively. After pretreatment by the combined ZVI-Fenton process under the optimal conditions, aromatic organic compound removal was as high as 77.2%, while the majority of COD remained to be further treated by sequent biological process. The combined anaerobic-aerobic process consisted of an anaerobic baffled reactor (ABR) and a moving-bed biofilm reactor (MBBR) was operated for 3 months, fed with ZVI-Fenton effluent. The results revealed that the coupled ZVI-Fenton-ABR-MBBR system was significantly efficient in terms of correcting the effluent's main parameters of relevance, mainly aromatic compounds concentration, COD concentration, color and acute toxicity. These results indicate that the combined ZVI-Fenton process offers bright prospects for the pretreatment of wastewater containing nitroaromatic compounds

  20. The fate of MtBE during Fenton-like treatments through laboratory scale column tests

    Science.gov (United States)

    Piscitelli, Daniela; Zingaretti, Daniela; Verginelli, Iason; Gavasci, Renato; Baciocchi, Renato

    2015-12-01

    In Situ Chemical Oxidation (ISCO) based on the Fenton's process is a proven technology for the treatment of groundwater contaminated by organic compounds. Nevertheless, the application of this treatment process to methyl tert-butyl ether (MtBE) is questioned, as there are concerns about its capacity to achieve complete mineralization. Many existing studies have focused on water contaminated by MtBE and are thus not representative of in situ treatments since they do not consider the presence of soil. In this work, the effectiveness of a Fenton-like process for MtBE treatment was proven in soil column tests performed at operating conditions (i.e., oxidant and contaminant concentration and flow rates) resembling those typically used for in situ applications. No MtBE by-products were detected in any of the tested conditions, thus suggesting that the tert-butyl group of MtBE was completely degraded. A mass balance based on the CO2 produced was used as evidence that most of the MtBE removed was actually mineralized. Finally, the obtained results show that preconditioning of soil with a chelating agent (EDTA) significantly enhanced MtBE oxidation.

  1. Photo-Fenton-like degradation of azo dye methyl orange using synthetic ammonium and hydronium jarosite

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Zhihui [Department of Chemistry, College of Science, Nanjing Agricultural University, Nanjing 210095 (China); Liang, Jianru [Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095 (China); Zhou, Lixiang, E-mail: lxzhou@njau.edu.cn [Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095 (China)

    2013-01-05

    Highlights: Black-Right-Pointing-Pointer Hydronium and ammonium jarosite could catalyze the oxidation of methyl orange in photo-Fenton-like process. Black-Right-Pointing-Pointer The oxidation process is essentially heterogeneous, not homogeneous. Black-Right-Pointing-Pointer Hydronium jarosite has stronger reactivity than ammonium jarosite. - Abstract: Ammonium and hydronium jarosite were prepared by hydrothermal method with urea as the homogeneous precipitant. X-ray diffraction, field-emission scanning electron microscope, X-ray photoelectron spectrum, UV-vis spectra and fourier transform infrared spectrum were used to characterize the resulting products. The photodegradation efficiency of the prepared ammonium and hydronium jarosite was studied in a photo-Fenton-like process using methyl orange (MO) as target pollutant. The photocatalytic degradation of MO over synthetic ammonium and hydronium jarosite under various conditions, such as catalysts loading, H{sub 2}O{sub 2} concentration and initial pH, has been investigated. Results show that ammonium and hydronium jarosite have satisfactory photocatalysis effect in degradation of MO azo dye, and that the reactivity of hydronium jarosite toward the mineralization of MO was higher than that of ammonium jarosite. The novel ammonium and hydronium jarosite catalysts would be important for industrial applications due to their high photoactivity, little iron leaching and low cost.

  2. Treatment of 1,10-phenanthroline laboratory wastewater using the solar photo-Fenton process

    International Nuclear Information System (INIS)

    The red Fe2+-phenanthroline complex is the basis of a classical spectrophotometric method for determination of iron. Due to the toxicity of this complexing agent, direct disposal of the wastewaters generated in analytical laboratories is not environmentally safe. This work evaluates the use of the solar photo-Fenton process for the treatment of laboratory wastewaters containing phenanthroline. Firstly, the degradation of phenanthroline in water was evaluated at two concentration levels (0.1 and 0.01%, w/v) and the efficiencies of degradation using ferrioxalate (FeOx) and ferric nitrate were compared. The 0.01% w/v solution presented much higher mineralization, achieving 82% after 30 min of solar irradiation with both iron sources. The solar photo-Fenton treatment of laboratory wastewater containing, in addition to phenanthroline, other organic compounds such as herbicides and 4-chlorophenol, equivalent to 4500 mg L-1 total organic carbon (TOC) resulted in total degradation of phenanthroline and 25% TOC removal after 150 min, in the presence of either FeOx or ferric nitrate. A ratio of 1:10 dilution of the residue increased mineralization in the presence of ferrioxalate, achieving 38% TOC removal after 120 min, while use of ferric nitrate resulted in only 6% mineralization over the same period

  3. Water quality in the vicinity of Fenton Hill. Progress report 1981 and 1982

    Energy Technology Data Exchange (ETDEWEB)

    Purtymun, W.D.; Ferenbaugh, R.W.; Becker, N.M.; Adams, W.H.; Maes, M.N.

    1983-09-01

    As part of a continuing program of environmental studies, water quality data have been collected from established surface and ground water stations and from ponds and pond discharges at Fenton Hill Site located in the Jemez Mountains. Most of these stations were established in 1973, and water quality data have been collected since that time. There have been slight variations in the chemical quality of water from the surface and ground water locations; however, these variations are within normal seasonal fluctuations. The discharge from ponds at Fenton Hill infiltrates into canyon alluvium within 400 m of the site. Monitoring surface and spring discharge downgradient from the ponds failed to detect any effects resulting from water released from the ponds. Total dissolved solids and calcium have increased in water from well FH-1, which furnishes the water supply for the site. This increase is caused by the decreasing water level in the well resulting in yield from beds with a slightly different quality than has been found in previous years.

  4. Evaluation of the photo-Fenton process on discoloration of a commercial textile dye

    Directory of Open Access Journals (Sweden)

    Andressa Antunes Bortoti

    2016-03-01

    Full Text Available The present study aimed to evaluate the applicability of photo-Fenton process for the degradation of a red colored commercial dye (Guarany® Tingecor 09. The process optimization was performed using a 23 factorial design, varying the volumes added of Fe3+ and H2O2 and the pH of the medium. The solutions containing the dye and the Fenton reagent were irradiated in a photoreactor equipped with a mercury vapor lamp of 125 W and the process development was accompanied by the acquisition of the absorption spectra UV-Vis in 10-minute intervals. The experimental design has shown that the best results were obtained with less amount of Fe3+ (0.1 ml, larger volume of H2O2 (1.0 mL and pH 5. The efficiency of the dye decolorization was evaluated by a phytotoxicity test employing Lactuca sativa L. seeds. The results showed to be satisfactory for the dye decolorization, and the wastes produced in the degradation process didn’t show toxicity.

  5. Removal of residual contaminants in petroleum-contaminated soil by Fenton-like oxidation

    International Nuclear Information System (INIS)

    The degradation of bioremediation residues by hydrogen peroxide in petroleum-contaminated soil was investigated at circumneutral pH using a Fenton-like reagent (ferric ion chelated with EDTA). Batch tests were done on 20 g soil suspended in 60 mL aqueous solution containing hydrogen peroxide and Fe3+-EDTA complex under constant stirring. A slurry reactor was used to treat the soil based on the optimal reactant conditions. Contaminants were characterized by Fourier transform infrared spectroscopy and Fourier transform ion cyclotron resonance mass spectrometry. The results showed that the optimal treatment condition was: the molar ratio of hydrogen peroxide to iron = 200:1, and pH 7.0. Under the optimum condition, total dichloromethane-extractable organics were reduced from 14,800 to 2300 mg kg-1 soil when the accumulative H2O2 dosage was 2.45 mol kg-1 soil during the reactor treatment. Abundance of viable cells was lower in incubated Fenton-like treated soil than in untreated soil. Oxidation of contaminants produced remarkable compositional and structural modifications. A fused ring compound, identified as C34H38N1, was found to exhibit the greatest resistance to oxidation.

  6. Olive mill effluent depuration by ozonation and Fenton processes enhanced by iron wastes.

    Science.gov (United States)

    Martins, Rui C; Ramos, Carina M; Henriques, Lucy R; Quinta-Ferreira, Rosa M

    2016-01-01

    The aim of the present work was to compare the potential of iron industry wastes to enhance ozone and hydrogen peroxide action on the degradation of olive mill wastewaters (OMWs). The results attained show a higher efficiency for ozonation using a lower catalyst load. Nevertheless, Fenton's process led to a larger amount of chemical oxidation demand (COD) removed per mole of oxidant applied. It was concluded that hydroxyl radicals are responsible for the pollutant abatement. High eco-toxicity decay was observed after the treatments. Furthermore, a preliminary analysis of the iron shavings' stability was made by reusing it in two feed-batch trials. It was concluded that while activity was maintained for Fenton's, a decrease of about 20% was verified for catalytic ozonation. Comparing these results with the ones obtained for the same processes applied to an actual OMW, a lower percentage of COD abatement was achieved. However, when reporting the amount of COD removed per mole of oxidant used, the difference between effluents are not so high. This should be taken into account when deciding which process should be implemented at an industrial scale. With the outcomes of this research it was possible to conclude that integrating waste management with wastewater treatment was feasible. PMID:26942537

  7. Environmental studies conducted at the Fenton Hill Hot Dry Rock geothermal development site

    Energy Technology Data Exchange (ETDEWEB)

    Miera, F.R. Jr.; Langhorst, G.; McEllin, S.; Montoya, C.

    1984-05-01

    An environmental investigation of Hot Dry Rock (HDR) geothermal development was conducted at Fenton Hill, New Mexico, during 1976-1979. Activities at the Fenton Hill Site included an evaluation of baseline data for biotic and abiotic ecosystem components. Identification of contaminants produced by HDR processes that had the potential for reaching the surrounding environment is also discussed. Three dominant vegetative communities were identified in the vicinity of the site. These included grass-forb, aspen, and mixed conifer communities. The grass-forb area was identified as having the highest number of species encountered, with Phleum pratense and Dactylis glomerata being the dominant grass species. Frequency of occurrence and mean coverage values are also given for other species in the three main vegetative complexes. Live trapping of small mammals was conducted to determine species composition, densities, population, and diversity estimates for this component of the ecosystem. The data indicate that Peromyscus maniculatus was the dominant species across all trapping sites during the study. Comparisons of relative density of small mammals among the various trapping sites show the grass-forb vegetative community to have had the highest overall density. Comparisons of small mammal diversity for the three main vegetative complexes indicate that the aspen habitat had the highest diversity and the grass-forb habitat had the lowest. Analyses of waste waters from the closed circulation loop indicate that several trace contaminants (e.g., arsenic, cadmium, fluoride, boron, and lithium) were present at concentrations greater than those reported for surface waters of the region.

  8. ELECTROCHEMICAL INCINERATION OF REFRACTORY ORGANIC POLLUTION BY ELECTROCHEMICALLY GENERATED FENTON'S REAGENT

    Directory of Open Access Journals (Sweden)

    AZRI YAMINA MOUNIA

    2012-01-01

    Full Text Available The electro-Fenton process is an electrochemical method for waste water treatment based on the production of hydroxyl radicals via H2O2 generation in the presence of ferrous ions. The aim of this work is of applied Electro-Fenton technique to incinerate lubricate additive biocide N,N-methylenebismorpholine (C9H18N2O2.the effect of some operational parameters such as applied cathodic potential, the electrolysis time and aeration,concentration of supporting electrolyte on the generation of H2O2 was investigated. The optimal cathodic potential on the generation of H2O2 production was -500mV/SCE corresponding to a density current of 1.4 mA/cm², the production of hydrogen peroxide with the aeration and electrolysis time, then became stationary after 2h of electrolysis, the low pH favorite production of H2O2 electro generated. Whereas the Concentrations of supporting electrolyte of the solution have a slight affect. The degradation and incineration of N,N-methylenebismorpholine in the optimized parameters was also investigated (potential, current density, COD/Fe²+ ratio the result indicates that 97% of COD was incinerated at 50mA and the optimal concentration of catalyst is between 28 and 58mg/l.

  9. Photo-Fenton-like degradation of azo dye methyl orange using synthetic ammonium and hydronium jarosite

    International Nuclear Information System (INIS)

    Highlights: ► Hydronium and ammonium jarosite could catalyze the oxidation of methyl orange in photo-Fenton-like process. ► The oxidation process is essentially heterogeneous, not homogeneous. ► Hydronium jarosite has stronger reactivity than ammonium jarosite. - Abstract: Ammonium and hydronium jarosite were prepared by hydrothermal method with urea as the homogeneous precipitant. X-ray diffraction, field-emission scanning electron microscope, X-ray photoelectron spectrum, UV–vis spectra and fourier transform infrared spectrum were used to characterize the resulting products. The photodegradation efficiency of the prepared ammonium and hydronium jarosite was studied in a photo-Fenton-like process using methyl orange (MO) as target pollutant. The photocatalytic degradation of MO over synthetic ammonium and hydronium jarosite under various conditions, such as catalysts loading, H2O2 concentration and initial pH, has been investigated. Results show that ammonium and hydronium jarosite have satisfactory photocatalysis effect in degradation of MO azo dye, and that the reactivity of hydronium jarosite toward the mineralization of MO was higher than that of ammonium jarosite. The novel ammonium and hydronium jarosite catalysts would be important for industrial applications due to their high photoactivity, little iron leaching and low cost.

  10. Effects of Fenton's Reagent on aquifer geochemistry and microbiology at the A/M Area, Savannah River Site

    International Nuclear Information System (INIS)

    This report details the results of an investigation of Site conditions following a successful 1997 demonstration of in-situ DNAPL destruction by injection of Fenton's Reagent (hydrogen peroxide and ferrous sulfate solution) into DNAPL-bearing zones of an aquifer

  11. Leachate treatment system using constructed wetlands, Town of Fenton sanitary landfill, Broome County, New York. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1993-11-01

    Municipal sanitary landfills generate leachate that New York State regulations require to be collected and treated to avoid contaminating surface water and groundwater. One option for treating leachate is to haul it to municipal wastewater treatment facility. This option may be expensive, may require excessive energy for transportation, and may require pretreatment to protect the receiving facility`s processes. An alternative is on-site treatment and discharge. Personnel from the Town of Fenton, New York; Hawk Engineering, P.C.; Cornell University; and Ithaca College designed, built, and operated a pilot constructed wetland for treating leachate at the Town of Fenton`s municipal landfill. The system, consisting of two overland flow beds and two subsurface flow beds has been effective for 18 months in reducing levels of ammonia (averaging 85% removal by volatilization and denitrification) and total iron (averaging 95% removal by precipitation and sedimentation), two key constituents of the Fenton landfill`s leachate. The system effects these reductions with zero chemical and energy inputs and minimal maintenance. A third key constituent of the leachate, manganese, apparently passes through the beds with minimal removal. Details and wetland considerations are described.

  12. Effects of UV irradiation on humic acid removal by ozonation, Fenton and Fe0/air treatment: THMFP and biotoxicity evaluation

    International Nuclear Information System (INIS)

    Highlights: → Fe0/air rapidly and effectively removed HA within 9 min and its COD, biotoxicity and THMFP were low. → THMFP of ozonation-treated solution was much higher than those of Fenton-treated and Fe0/air-treated solutions. → UV irradiation during ozonation and Fenton oxidation enhanced HA removal, but did not reduce the THMFP of the treated solutions. → Fe0/air treatment with UV irradiation obviously increased the THMFP of the treated solution. → The relationship between biotoxicity and chloroform in the chlorinated solution was insignificant. - Abstract: Effects of UV irradiation on humic acid (HA) removal by Fe0/air, ozonation and Fenton oxidation were investigated. The trihalomethane forming potential (THMFP) and toxicity of treated solutions were also evaluated. The experimental conditions were ozone of 21 mg min-1, H2O2 of 8 x 10-4 M, Fe0 of 20 g L-1, air flow of 5 L min-1, and UVC of 9 W. Results indicated that Fe0/air rapidly removed HA color (>99%) and COD (90%) within 9 min. 51-81% of color and 43-50% of COD were removed by ozonation and Fenton oxidation after 60 min. Both UV enhanced ozone and Fenton oxidation removed HA, but the Fe0/air process did not. Spectrum results showed all processes effectively diminished UV-vis spectra, except for ozonation. The THMFP of Fe0/air-treated solution (114 μg L-1) was much lower than those of Fenton- (226 μg L-1) and ozonation-treated solutions (499 μg L-1). Fe0/air with UV irradiation obviously increased the THMFP of treated solution (502 μg L-1). The toxicity results obtained from Vibrio fischeri light inhibition test indicated that the toxicity of Fe0/air-treated solution (5%) was much lower than that of ozonation- (33%) and Fenton-treated solutions (31%). Chlorination increased the solution toxicity. The correlation between biotoxicity and chloroform in the chlorinated solution was insignificant.

  13. Heterogeneous photo-Fenton degradation of acid red B over Fe2O3 supported on activated carbon fiber

    International Nuclear Information System (INIS)

    Highlights: • Fe2O3 with small particle size was highly dispersed on activated carbon fiber. • Fe2O3/ACF exhibited higher photo-Fenton activity toward ARB degradation. • Fe2O3/ACF has an excellent long-term stability without obvious deactivation. - Abstract: Fe2O3 supported on activated carbon fiber (Fe2O3/ACF) was prepared via an impregnation method and characterized by X-ray diffraction, scanning electron microscopy and BET analysis. The results indicated that Fe2O3 with small particle size was highly dispersed on the surface of the ACF and the introduction of Fe2O3 did not change the ACF pore structure. Fe2O3/ACF exhibited a higher Fenton efficiency for the degradation of acid red B (ARB), especially under simulated solar irradiation. Complete decoloration of the ARB solution and 43% removal of TOC could be achieved within 200 min under optimal conditions. It was verified that more ·OH radicals were generated in the photo-assisted Fenton process and involved as active species in ARB degradation. FTIR analysis indicated that the degradation of ARB was initiated through the cleavage of −N=N−, followed by hydroxylation and opening of phenyl rings to form aliphatic acids, and further oxidation of aliphatic acids would produce CO2 and H2O. Moreover, Fe2O3/ACF maintained its activity after being reused 4 times and the release of iron from the catalyst was found to be insignificant during the Fenton and photo-Fenton processes, indicating that Fe2O3/ACF had good long-term stability

  14. Application of iron electrode corrosion enhanced electrokinetic-Fenton oxidation to remediate diesel contaminated soils: A laboratory feasibility study

    Science.gov (United States)

    Tsai, Tzai-Tang; Sah, Jygau; Kao, Chih-Ming

    2010-01-01

    SummaryDiesel soil contamination on gas stations or refinery plants is a worldwide environmental problem. The main objectives of this study were to (1) evaluate the efficiency of electrokinetic (EK) by using different electrode materials (graphite and iron rods) and electrolytes (tap water, 0.01 M NaCl, and 0.1 M NaCl) on the remediation of diesel contaminated soils, and (2) evaluate the feasibility of total petroleum hydrocarbon-diesel (TPH-D) reducing in soils via EK-Fenton oxidation enhanced by corroded iron electrode. The EK and EK-Fenton experiments were conducted in batch and sand box experiments, respectively. Batch experiments reveal that the most appropriate electrolyte was 0.1 M NaCl when iron electrode was used in the EK system. Sand box experiments indicate that the TPH-D concentration dropped from 10,000 to 300 mg kg -1 when amorphous iron/total iron (Fe o/Fe t) ratio increased from 0.1 to 0.33, with the addition of 8% of H 2O 2 and 0.1 M NaCl after 60 days of EK-Fenton operation. Electrokinetically enhanced oxidation with the presence of both H 2O 2 and Fe 3O 4 (iron electrode corrosion) resulted in higher TPH-D removal efficiency (97%) compared to the efficiencies observed from EK (55%) or Fenton oxidation (27%) alone. This demonstrates that EK-Fenton oxidation catalyzed by iron electrode corrosion is a valuable direction to efficiently and effectively remediate diesel contaminated soils.

  15. Tratamento de lixiviados de aterros de resíduos sólidos utilizando Processos Fenton e Foto-Fenton Solar

    Directory of Open Access Journals (Sweden)

    Fábio Moraes da Costa

    2015-01-01

    Full Text Available O lixiviado de aterros de resíduos sólidos urbanos é uma complexa mistura de substâncias orgânicas e inorgânicas, que em sua composição causam danos ao meio ambiente, devido à elevada concentração de matéria orgânica recalcitrante e à toxicidade presente. A proposta deste trabalho envolve a aplicação dos processos oxidativos avançados (POA, como tratamento de lixiviado oriundos de dois aterros sanitários, Gericinó (Rio de Janeiro/RJ e Gramacho (Duque de Caxias/RJ, dois aterros com mais de 30 anos de operação, sendo que o último encontra-se encerrado há 2 anos. O objetivo da utilização dos POA é melhorar a qualidade do lixiviado para um tratamento biológico subsequente, para isso foi utilizado o ensaio com a bactéria Aliivibrio fischeri para avaliação da toxicidade. Para o Processo Fenton-escuro, realizado em escala de bancada, nos experimentos realizados a pH=3,0 e razão Fe+2:H2O2 igual a 1:5 foram obtidas remoções de 56% e 19% de DQO para os lixiviados oriundos de Gericinó e Gramacho, respectivamente. Para o Processo Foto-Fenton Solar, realizado em uma planta piloto, nos testes a pH=3,0 e razão Fe+2:H2O2 igual a 1:5, foram alcançadas 88% e 78% de remoção de DQO. Essas condições permitiram uma diminuição da toxicidade dos lixiviados pa ra valores de coeficiente de efeito igual a 50% (CE 50% para Aliivibrio fischeri maior que 50%, indicando um lixiviado mais adequado para tratamento biológico posterior.

  16. Influence of ultrasonication and Fenton oxidation pre-treatment on rheological characteristics of wastewater sludge.

    Science.gov (United States)

    Pham, T T H; Brar, S K; Tyagi, R D; Surampalli, R Y

    2010-01-01

    The effect of ultrasonication and Fenton oxidation as physico-chemical pre-treatment processes on the change of rheology of wastewater sludge was investigated in this study. Pre-treated and raw sludges displayed non-Newtonian rheological behaviour with shear thinning as well as thixotropic properties for total solids ranging from 10 g/L to 40 g/L. The rheological models, namely, Bingham plastic, Casson law, NCA/CMA Casson, IPC Paste, and power law were also studied to characterize flow of raw and pre-treated sludges. Among all rheological models, the power law was more prominent in describing the rheology of the sludges. Pre-treatment processes resulted in a decrease in pseudoplasticity of sludge due to the decrease in consistency index K varying from 42.4 to 1188, 25.6 to 620.4 and 52.5 to 317.9; and increase in flow behaviour index n changing from 0.5 to 0.35, 0.62 to 0.55 and 0.63 to 0.58, for RS, UlS and FS, respectively at solids concentration 10-40 g/L. The correlation between improvement of biodegradability and dewaterability, decrease in viscosity, and change in particle size as a function of sludge pre-treatment process was also investigated. Fenton oxidation facilitated sludge filterability resulting in capillary suction time values which were approximately 50% of the raw sludges, whereas ultrasonication with high input energy deteriorated the filterability. Biodegradability was also enhanced by the pre-treatment processes and the maximum value was obtained (64%, 77% and 73% for raw, ultrasonicated and Fenton oxidized sludges, respectively) at total solids concentration of 25 g/L. Hence, pre-treatment of wastewater sludge modified the rheological properties so that: (1) the flowability of sludge was improved for transport through the treatment train (via pipes and pumps); (2) the dewaterability of wastewater sludge was enhanced for eventual disposal and; (3) the assimilation of nutrients by microorganisms for further value-addition was increased. PMID

  17. Rapid degradation of methylene blue in a novel heterogeneous Fe3O4 @rGO@TiO2-catalyzed photo-Fenton system

    Science.gov (United States)

    Yang, Xiaoling; Chen, Wei; Huang, Jianfei; Zhou, Ying; Zhu, Yihua; Li, Chunzhong

    2015-05-01

    Herein, a ternary nanocomposite with TiO2 nanoparticles anchored on reduced graphene oxide (rGO)-encapsulated Fe3O4 spheres (Fe3O4@rGO@TiO2) is presented as a high efficient heterogeneous catalyst for photo-Fenton degradation of recalcitrant pollutants under neutral pH. Fe3O4@rGO@TiO2 was synthesized by depositing TiO2 nanoparticles on the surface of the Fe3O4 spheres wrapped by graphene oxide (GO) which was obtained by an electrostatic layer-by-layer method. This as-prepared catalyst reflected good ferromagnetism and superior stability which makes it convenient to be separated and recycled. Due to the synergic effects between the different components composed the catalyst, swift reduction of Fe3+ can be achieved to regenerate Fe2+. Fe3O4@rGO@TiO2 exhibited enhancing catalytic activity for the degradation of azo-dyes compared with Fe3O4, Fe3O4@SiO2@TiO2 or SiO2@rGO@TiO2, further conforming the rapid redox reaction between Fe2+ and Fe3+. All these merits indicate that the composite catalyst possesses great potential for visible-light driven destruction of organic compounds.

  18. Heterogeneous sono-Fenton-like process using nanostructured pyrite prepared by Ar glow discharge plasma for treatment of a textile dye.

    Science.gov (United States)

    Khataee, Alireza; Gholami, Peyman; Vahid, Behrouz

    2016-03-01

    The plasma-treated pyrite (PTP) nanostructures were prepared from natural pyrite (NP) utilizing argon plasma due to its sputtering and cleaning effects resulting in more active surface area. The NP and PTP were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Brunauer-Emmett-Teller (BET) and scanning electron microscopy (SEM) methods. The performance of the PTP was greater than NP for treatment of Reactive Red 84 (RR84) by the heterogeneous sono-Fenton process. The optimum amounts of main operational parameters were obtained as PTP of 4 g/L, initial dye concentration of 10 mg/L, pH of 5, and ultrasonic power of 300 W after 120 min of reaction time. Also, the effects of enhancers, and inorganic salts and t-butanol as hydroxyl radical scavengers on the degradation efficiency were investigated. Gas chromatography-mass spectroscopy analysis (GC-MS) was applied for detection of some degradation intermediates. Environmentally friendly plasma modification of the NP, in situ production of H2O2 and OH radicals, low leached iron concentration and repeated reusability at the milder pH are the significant benefits of the PTP utilization. PMID:26585001

  19. Catalytic degradation of recalcitrant pollutants by Fenton-like process using polyacrylonitrile-supported iron (II) phthalocyanine nanofibers: Intermediates and pathway.

    Science.gov (United States)

    Zhu, Zhexin; Chen, Yi; Gu, Yan; Wu, Fei; Lu, Wangyang; Xu, Tiefeng; Chen, Wenxing

    2016-04-15

    Iron (II) phthalocyanine (FePc) molecules were isolated in polyacrylonitrile (PAN) nanofibers by electrospinning to prevent the formation of dimers and oligomers. Carbamazepine (CBZ) and Rhodamine B (RhB) degradation was investigated during a Fenton-like process with FePc/PAN nanofibers. Classical quenching tests with isopropanol and electron paramagnetic resonance tests with 5,5-dimethyl-pyrroline-oxide as spin-trapping agent were performed to determine the formation of active species during hydrogen peroxide (H2O2) decomposition by FePc/PAN nanofibers. After eight recycles for CBZ degradation over the FePc/PAN nanofibers/H2O2 system, the removal ratios of CBZ remained at 99%. Seven by-products of RhB and twelve intermediates of CBZ were identified using ultra-performance liquid chromatography and high-resolution mass spectrometry. Pathways of CBZ and RhB degradation were proposed based on the identified intermediates. As the reaction proceeded, all CBZ and RhB aromatic nucleus intermediates decreased and were transformed to small acids, but also to potentially toxic epoxide-containing intermediates and acridine, because of the powerful oxidation ability of •OH in the catalytic system. PMID:26949842

  20. Vanillic and syringic acids from biomass burning: Behaviour during Fenton-like oxidation in atmospheric aqueous phase and in the absence of light.

    Science.gov (United States)

    Santos, Gabriela T A D; Santos, Patrícia S M; Duarte, Armando C

    2016-08-01

    Biomass combustion is a threat to the environment since it emits to the atmosphere organic compounds, which may react and originate others more aggressive. This work studied the behaviours of vanillic and syringic acids, small aromatic tracers of biomass burning, during Fenton-like oxidation in aqueous phase and absence of light. For both compounds, the extent of oxidation increased with pH decrease from neutral to acid in atmospheric waters, but for vanillic acid the neutral pH was not able of promoting the oxidation. With the oxidation of both acids were formed chromophoric compounds, and the formation rate increased with the degree of electron-donator substituents in benzene ring. The initial and produced compounds were not totally degraded up to 24h of reaction at pH 4.5, suggesting that the night period may be not sufficient for their full degradation in atmospheric waters. The major compounds formed were the 3,4-dihydroxybenzoic acid for vanillic acid, and the 1,4-dihydroxy-2,6-dimethoxybenzene for syringic acid. These findings suggest the occurrence of an ipso attack by the hydroxyl radical preferential to the methoxy and carboxyl groups of vanillic and syringic acids, respectively. It is important to highlight that for both aromatic acids the main compounds produced are also small aromatic compounds. PMID:27085101

  1. A novel Electro-Fenton-Like system using PW{sub 11}O{sub 39}Fe(III)(H{sub 2}O){sup 4-} as an electrocatalyst for wastewater treatment

    Energy Technology Data Exchange (ETDEWEB)

    Wang Chongtai [School of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158, Hainan Province (China); Hua Yingjie, E-mail: 521000hua282@sina.co [School of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158, Hainan Province (China); Tong Yexiang [Institute of Optoelectronic and Functional Composite Materials, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275 (China)

    2010-09-01

    A novel Electro-Fenton-Like (EFL) system was developed using the Keggin-type iron-substituted heteropolytungstate anion PW{sub 11}O{sub 39}Fe(III)(H{sub 2}O){sup 4-} to substitute for Fe{sup 3+} in the conventional Electro-Fenton (EF) system for treatment of water polluted with organic compounds. The EFL system overcomes the drawback of low pH in conventional EF approaches and can be directly applied to neutral water treatment without any pH adjustment. Experimental results for dimethylphthalate (DMP) revealed complete degradation in <80 min in pH 6.86 solution containing 0.1 mM DMP at a potential of -0.5 V and O{sub 2} flow rate of 60 mL min{sup -1}. Total organic carbon removal of {approx}56% was achieved at 120 min. Comparison with conventional EF oxidation revealed better efficiency of the present system for DMP degradation, suggesting its potential in treatment of water and wastewater with a relaxed pH requirement. The cumulative H{sub 2}O{sub 2} concentration generated in situ at the electrode was monitored and the observed degradation rate constants k{sub obs} were determined for different initial DMP concentrations. The ligand exchange reaction of PW{sub 11}O{sub 39}Fe(III)(H{sub 2}O){sup 4-} with H{sub 2}O{sub 2} and the electron transfer resulting in hydroxyl radicals were examined using HPLC and electrochemical impedance spectroscopy. An electrocatalytic model involving inner-sphere electron transfer and a reaction mechanism for PW{sub 11}O{sub 39}Fe(III)(H{sub 2}O){sup 4-} electrocatalytic reduction of H{sub 2}O{sub 2} are proposed.

  2. Pretreatment of 2,4-dinitroanisole (DNAN) producing wastewater using a combined zero-valent iron (ZVI) reduction and Fenton oxidation process.

    Science.gov (United States)

    Shen, Jinyou; Ou, Changjin; Zhou, Zongyuan; Chen, Jun; Fang, Kexiong; Sun, Xiuyun; Li, Jiansheng; Zhou, Lin; Wang, Lianjun

    2013-09-15

    A combined zero-valent iron (ZVI) reduction and Fenton oxidation process was tested for the pretreatment of 2,4-dinitroanisole (DNAN) producing wastewater. Operating conditions were optimized and overall performance of the combined process was evaluated. For ZVI process, almost complete reduction of nitroaromatic compounds was observed at empty bed contact time (EBCT) of 8h. For Fenton process, the optimal pH, H₂O₂ to Fe(II) molar ratio, H₂O₂ dosage and hydraulic retention time (HRT) were found to be 3.0, 15, 0.216 mol/L and 5h, respectively. After pretreatment by the combined ZVI-Fenton process under the optimal conditions, aromatic organic compound removal was as high as 77.2%, while the majority of COD remained to be further treated by sequent biological process. The combined anaerobic-aerobic process consisted of an anaerobic baffled reactor (ABR) and a moving-bed biofilm reactor (MBBR) was operated for 3 months, fed with ZVI-Fenton effluent. The results revealed that the coupled ZVI-Fenton-ABR-MBBR system was significantly efficient in terms of correcting the effluent's main parameters of relevance, mainly aromatic compounds concentration, COD concentration, color and acute toxicity. These results indicate that the combined ZVI-Fenton process offers bright prospects for the pretreatment of wastewater containing nitroaromatic compounds. PMID:23892166

  3. Water quality in the vicinity of Fenton Hill: Progress report, 1983 and 1984

    Energy Technology Data Exchange (ETDEWEB)

    Purtymun, W.D.; Ferenbaugh, R.W.; Becker, N.M.; Williams, M.C.; Maes, M.

    1987-01-01

    Water quality data have been collected since 1974 from established surface and groundwater stations at and in the vicinity of Fenton Hill (Hot Dry Rock Geothermal Demonstration Site) located in the Jemez Mountains. This is part of a continued program of environmental studies. There has been a slight variation in chemical quality of water from the surface and groundwater stations; however, these variations are within normal seasonal fluctuations. Water supply at the site is pumped from the aquifer in the Abiquiu Tuff. Cumulative production from 1976 through 1984 has been 41.5 x 10/sup 6/ gal. The water level in the supply well declined from 365 ft in 1976 to 379 ft in 1984.

  4. Dégradation des polluants organiques par la technologie électro-fenton

    OpenAIRE

    Özcan, Ali

    2010-01-01

    Une étude détaillée a été effectuée sur l'utilisation de la technique électro-Fenton pour l'oxydation de quelques polluants organiques persistants (POP) dans le but du traitement des eaux usées. Cette technique génère, in situ et de manière électrocatalytique, les radicaux hydroxyles (OH) afin de les utiliser pour oxyder la polluants organiques. Le travail de thèse est constitué en trois parties. Dans la première partie, l'élimination de l'eau des colorants synthétiques et pesticides choisis ...

  5. Degradation of persistent organic pollutants by Fenton's reagent facilitated by microwave or high-intensity ultrasound.

    Science.gov (United States)

    Cravotto, G; di Carlo, S; Tumiatti, V; Roggero, C; Bremner, H D

    2005-07-01

    Microwave (MW) and high-intensity ultrasound (US) have emerged as powerful techniques for the elimination of persistent organic pollutants (POPs) that constitute a major health hazard, whether by direct exposure or through accumulation in biota. In order to achieve decontamination, POPs should be completely mineralized to CO2, H2O and smaller amounts of inorganic ions, or at least converted to less harmful chemical species. Under US or MW irradiation rapid degradation of aromatic halides, halogenated phenols and polychlorinated biphenyls in polluted waters was achieved at neutral pH in the presence of a moderate excess (5-30 eq) of Fenton's reagent. Acidification with acetic acid (pH 2.0-2.3) did not affect the process, but sulphuric acid (pH 1.7-2.0) facilitated complete degradation. Thus, compared to conventional methods, US and MW processes are faster and much more efficient. PMID:16080327

  6. Revisiting Fenton Hill Phase I reservoir creation and stimulation mechanisms through the GTO code comparison effort

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Pengcheng; Mcclure, Mark; Shiozawa, Sogo; White, Mark D.

    2016-06-27

    A series of experiments performed at the Fenton Hill hot dry rock site after stage 2 drilling of Phase I reservoir provided intriguing field observations on the reservoir’s responses to injection and venting under various conditions. Two teams participating in the US DOE Geothermal Technologies Office (GTO)’s Code Comparison Study (CCS) used different numerical codes to model these five experiments with the objective of inferring the hydraulic stimulation mechanism involved. The codes used by the two teams are based on different numerical principles, and the assumptions made were also different, due to intrinsic limitations in the codes and the modelers’ personal interpretations of the field observations. Both sets of models were able to produce the most important field observations and both found that it was the combination of the vertical gradient of the fracture opening pressure, injection volume, and the use/absence of proppant that yielded the different outcomes of the five experiments.

  7. Avaliação da microfiltração para remoção do lodo gerado no processo oxidativo avançado empregando o reagente de Fenton no tratamento de lixiviado de aterro sanitário Evaluation of microfiltration for removal of sludge generated in advanced oxidation process by Fenton reagent in treatment of landfill leachate

    Directory of Open Access Journals (Sweden)

    Wagner Guadagnin Moravia

    2011-12-01

    Full Text Available Uma alternativa atrativa para o tratamento de lixiviado de aterro sanitário são os processos oxidativos avançados empregando o reagente de Fenton (POA/Fenton. No entanto, a aplicação do POA/Fenton é limitada pela geração de lodo no processo. Esse lodo possui elevada concentração de ferro, o que torna necessária sua separação do efluente tratado. O objetivo desse trabalho foi avaliar a microfiltração para a remoção de lodo gerado no POA/Fenton. A pesquisa foi desenvolvida em unidade de bancada. O POA/Fenton apresentou elevada eficiência na remoção de matéria orgânica (75% e cor real (95%. O processo de microfiltração foi eficiente na separação do lodo gerado, o qual apresentou baixa sedimentabilidade, dificultando sua separação por sedimentação, além de ter contribuído para a remoção de outros poluentes.Advanced oxidation processes using Fenton's reagent (AOP/Fenton are an attractive alternative for landfill leachate treatment. However, the implementation of the AOP/Fenton is limited by the generation of sludge in the process. The sludge has a high iron concentration, which needs its separation from the treated effluent. The aim of this study was to evaluate the microfiltration for sludge removal from an AOP/Fenton. The work was conducted in bench scale. The advanced oxidation process showed high efficiency in removing organic matter (75% and true color (95%. The microfiltration was effective in separating the sludge, which showed low settling hindering their separation by sedimentation, and has contributed to the removal of other pollutants.

  8. Study on Degradation of Musty-earthy Odors by Heterogeneous UV/Fenton Photocatalysis%非均相UV/Fenton光催化降解土霉异味研究

    Institute of Scientific and Technical Information of China (English)

    刘立明; 李林; 闪锟; 黄应平; 宋立荣

    2012-01-01

    [目的]探索非均相UV/Fenton光催化降解土霉异味的效果.[方法]利用离子交换方法将Fe2+负载在NaY分子筛载体上,制得催化剂FeY.在不同紫外波长照射下,利用Fenton反应降解2种土霉异味物质2-甲基异莰醇(MIB)和土腥素(Geosmin),优化pH和H2O2等降解条件,并将MIB和Geosmin添加到东湖本底湖水中进行降解.[结果]FeY的负载量为352.8 mg/g,Fe2+脱附率为5.7%.在FeY为28 mg/L,pH 6.5,H2O2 20 mg/L和反应60min的试验条件下,非均相UVB/Fenton体系对MIB和Geosmin的降解率分别为80.2%和84.9%.在UVA、UVB和UVC紫外光(波长分别为365、312和256 nm)条件下Photo-Fenton体系对MIB和Geosmin的降解率,随着紫外波长的降低而增大,且Geosmin降解速率常数高于MIB.湖泊水样中加入MIB和Geosmin降解表明,降解效率明显低于纯水样品.[结论]该研究制得的催化剂应用于非均相光催化体系,不仅可循环使用,而且还可扩大反应体系的pH应用范围.%[Objective] The study aimed to explore the effects of the heterogeneous UV/Fenton photocatalysis on the degradation of the musty-earthy odors. [ Result] By using ion exchange method, the Fe2+ was loaded on the NaY molecular sieve carrier to prepare the catalyst FeY. Under the radiation of different ultraviolet wavelengths, 2 musty-earthy odor materials of 2-Methylisobomeol ( MIB) and trans-1, 10-dimethyl-trans-9-decalol (Geosmin) were degraded by using Fenton reaction, the degradation conditions such as pH and H2O2 were optimized and the MIB and Geosmin were added to the bottom of East Lake for the degradation. [ Conclusion] The FeY loading amount was 352.8 mg/g and the Fe2+ desorption rate was 5. 7%. The heterogeneous UV/Fenton system had the degradation rate of 80. 2% and 84. 9% resp. On MIB and Geosmin under the test conditions as FeY of 28 mg, pH of 6.5, H2O2 of 20 mg/L and reaction time of 60 min. Under the UVA, UVB and UVC wavelengths of 365 ,312 and 256 nm, resp. , the

  9. 铁炭微电解法、Fenton氧化法处理印染废水的效果比较%Comparison of Iron-carbon microelectrolysis and Fenton oxidation on treatment of dyeing wastewater

    Institute of Scientific and Technical Information of China (English)

    丁绍兰; 汪晶; 杜虎

    2013-01-01

    [目的]印染废水具有浓度高、色度高、成分复杂、难降解的特点,比较了铁炭微电解法和Fenton氧化法处理印染废水的效果.[方法]以取自陕西咸阳第二印染厂的综合废水为供试材料,通过单因素试验,分别对铁炭微电解法和Fenton氧化法处理印染废水的最佳条件进行了研究,并对二者的处理效果进行了比较.[结果]在处理印染废水时,铁炭微电解法的最佳反应条件为:停留时间30 min,进水pH=3~4,铁炭体积比1∶1,此时色度去除率达到80%,COD去除率达到60%;Fenton氧化法的最佳反应条件为:pH=3,停留时间45 min,H2O2和FeSO4用量分别为20,25 mL/L,H2O2分3次加入,此条件下色度去除率达到79%,COD去除率达到80%.[结论]铁炭微电解法和Fenton氧化法对印染废水均有较好的处理效果,可考虑将两者联合运用,以进一步提高处理效果.%[Objective] Dyestuff wastewater is a typical kind of biorefractory wastewater with high concentration, high chroma,complicated components and low degradability. [Method] Dyeing wastewater from the Second Printing and Dyeing Mill of Xianyang,Shaanxi was chosen as experimental material to study the optimal conditions of for Iron-carbon microelectrolysis and Fenton oxidation using the single-factor experiments. The treatment effects of the two methods were compared as well. [Result] In disposing printing and dyeing waste water,optimum reaction conditions of Iron-carbon microelectrolysis were as follows:exposure time was 30 min,pH value was 3 -4, volume ratio of iron to carbon was l,and chroma and COD removal efficiency were 80% and 60%, respectively. Optimum reaction conditions of Fenton oxidation were as follows :pH value was 3, exposure time was 45 minutes, the dosage of hydrogen peroxide was 20 mL/L and ferrous sulphate was 25 mL/L, the hydrogen peroxide was added in the reaction system three times, and chroma and COD removal efficiency were 79% and 80%, respectively

  10. Tratamento de água subterrânea contaminada com compostos organoclorados usando ferro elementar e o reagente de Fenton Treatment of groundwater contaminated with chlorinated compounds using elemental iron and Fenton's reagent

    Directory of Open Access Journals (Sweden)

    Tatiana Langbeck de Arruda

    2007-01-01

    Full Text Available The remediation of groundwater containing organochlorine compounds was evaluated using a reductive system with zero-valent iron, and the reductive process coupled with Fenton's reagent. The concentration of the individual target compounds reached up to 400 mg L-1 in the sample. Marked reductions in the chlorinated compounds were observed in the reductive process. The degradation followed pseudo-first-order kinetics in terms of the contaminant and was dependent on the sample contact time with the solid reducing agent. An oxidative test with Fenton's reagent, followed by the reductive assay, showed that tetrachloroethylene was further reduced up to three times the initial concentration. The destruction of chloroform, however, demands an additional treatment.

  11. Evaluation of Fenton Oxidation Process Coupled with Biological Treatment for the Removal of Reactive Black 5 from Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Pegah Bahmani

    2013-06-01

    Full Text Available Biodegradation of azo dyes is difficult due to their complex structures and low BOD to COD ratios. In the present study, the efficiency of using Fenton’s reagent (H2O2 + Fe2+ as a pretreatment process to enhance microbial transformation of reactive black 5 (RB5 in an aqueous system was evaluated. The RB5 with an initial concentration of 250 mg/L was decolorized up to 90% in 60 h by using a bacterial consortium. Fenton’s reagent at a Fe2+ concentration of 0.5 mM and H2O2 concentration of 2.9 mM (molar ratio, 1:5.8 was most effective for decolorization at pH = 3.0. The extent of RB5 removal by the combined Fenton–biotreatment was about 2 times higher than that of biotreatment alone. The production of some aromatic amines intermediates implied partial mineralization of the RB5 in Fenton treatment alone; in addition, decreasing of GC-MS peaks suggested that dearomatization occurred in Fenton-biological process. Fenton pretreatment seems to be a cost–effective option for the biotreatment of azo dyes, due mainly to the lower doses of chemicals, lower sludge generation, and saving of time. Our results demonstrated positive effects of inoculating bacterial consortium which was capable of dye biodegradation with a Fenton’s pretreatment step as well as the benefits of low time required for the biological process. In addition, the potential of field performance of Fenton-biological process because of using bacterial consortium is an other positive effect of it.

  12. Influence of Fenton's reagent treatment on electrochemical properties of graphite felt for all vanadium redox flow battery

    International Nuclear Information System (INIS)

    Highlights: ► Highly hydroxyl-functionalized graphite felt has been obtained through Fenton's reagent treatment. ► Fenton's reagent treatment involves only one step, works under ambient conditions and will never produce any toxic gas. ► The treated graphite felt exhibits superior electrochemical performance in comparison to the untreated one. -- Abstract: An environmental, economic and highly effective method for carbon fiber hydroxylated-functionalization based on Fenton's reagent treatment is used to improve the electrochemical activity of graphite felt (GF) as the positive electrode in all vanadium redox flow battery (VRFB). The effect of H2O2 content in Fenton's reagent on the structure and electrochemical properties of GF is investigated. The scanning electron microscope (SEM) indicates that the surface of the treated GF is etched increasingly with the content of H2O2. The Fourier transformation infrared (FTIR) spectroscopy shows that the peak intensity of hydroxyl groups on the treated felt is increased with the H2O2 concentration, which is further verified by X-ray photoelectron spectroscopy (XPS). Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) show that the treated sample exhibits a higher electrochemical activity. A VRFB with the treated GF as electrodes exhibits higher coulombic, voltage and energy efficiency (98.8%, 75.1% and 74.2%) than that with the untreated GF (93.9%, 72.1% and 67.7%) at 60 mA cm−2, and this method is even superior when compared with the reported methods

  13. Optimization of the Parameters Affecting the Fenton Process for Decolorization of Reactive Red 198 (RR-198) from the Aqueous Phase

    OpenAIRE

    Mansooreh Dehghani; Mahshid Ghadami; Talat Gholami; Marzieh Ansari Shiri; Zahra Elhameyan; Mohammad Reza Javaheri; Narges Shamsedini; Samaneh Shahsavani

    2015-01-01

    Background: Recently, there has been a great concern about the consumption of dyes because of their toxicity, mutagenicity, carcinogenicity, and persistence in the aquatic environment. Reactive dyes are widely used in textile industry. Advanced oxidation processes are one of the cost-effective methods for the removal of these dyes. The main aims of this study were determining the feasibility of using Fenton process in removing Reactive Red 198 (RR-198) dye from aqueous so...

  14. Degradation of industrial azo dye in aqueous solution by heterogeneous Fenton process (fly ash/H2O2)

    OpenAIRE

    Bečelić-Tomin Milena R.; Dalmacija Milena B.; Dalmacija Božo D.; Rajić Ljiljana M.; Tomašević Dragana D.

    2012-01-01

    The aim of this study was to investigate the possibilities and efficiency of heterogeneous Fenton process with the use of fly ash from thermal power plants Kolubara, Serbia, as the catalyst in the degradation of industrial azo dye Zetanyl Rosso B-NG. The effects of various experimental parameters such as pH, temperature, concentration of fly ash, the initial concentration of H2O2 and initial concentration of dye on the kinetics and efficiency of decolorization were investigated. Simulta...

  15. Abbau von epsilon-Caprolactam aus Abluftwäscherlaugen mittels Licht verstärkter Fenton-Reaktion

    OpenAIRE

    Heck, Edmund; Jung, Christian; de Oliveira, Lamark; Olwig, Ralf; Säck, Jan-Peter; Sattler, Christian; Schäfer, Thomas; Senholdt, Marion; Weskott, Klaus; Zinner, Dania

    2009-01-01

    Caprolactam-haltige Wässer aus Abluftwäschern der Veredlung von Nylongewebe können mittels der Licht verstärkten Fenton-Reaktion gereinigt und für die Kreislaufführung aufbereitet werden. Der Abbauweg des Caprolactams wurde untersucht, um die rasche Eliminierung zu erklären und um die Zwischenprodukte bis zur Mineralisierung zu identifizieren.

  16. Evaluation of Electro-Fenton Process Performance for COD and Reactive Blue 19 Removal from Aqueous Solution

    OpenAIRE

    Mohammad Malakootian; Mahdi Asadi; Amir Hossein Mahvi

    2013-01-01

    Background and Objectives: Synthetic dyes represent one of the largest groups of pollutants in wastewater of dying industries. Discharging these wastewaters into receiving streams not only affects the aesthetic but also reduces photosynthetic activity. Electrochemical advanced oxidation processes such as Electro-Fenton process are low operational and have high mineralization degree of pollutants. In this study, we investigated affective factors in this process to determine the optimum conditi...

  17. Degradation of atrazine by a novel Fenton-like process and assessment the influence on the treated soil.

    Science.gov (United States)

    Cheng, Min; Zeng, Guangming; Huang, Danlian; Lai, Cui; Xu, Piao; Zhang, Chen; Liu, Yang; Wan, Jia; Gong, Xiaomin; Zhu, Yuan

    2016-07-15

    This is the premier study reporting the remediation of atrazine contaminated soil with steel converter slag (SCS) catalyzed Fenton-like process. The effects of various operating parameters, such as SCS loads and H2O2 concentrations were evaluated with respect to the removal efficiency of atrazine. Results show the optimal SCS load and H2O2 concentration were 80gkg(-1) and 10%, respectably. The graded modified Fenton's oxidation with a 3-time addition of 10% H2O2 was able to remove 93.7% of total atrazine in the contaminated soil and maintain soil temperature within 50°C. In contrast to traditional Fenton treatment, a slight pH increase has been observed due to the addition of SCS. More importantly, experiment conducted at natural conditions with SCS gave the similar atrazine removal to the experiments with the other catalysts (e.g., FeSO4 and Fe2O3). One thing should be noted that after the treatment, dissolved organic carbon (DOC) content increased to 1.206gkg(-1) from an initial value of 0.339gkg(-1). PMID:27037472

  18. Treatment of Basic Red 29 dye solution using iron-aluminum electrode pairs by electrocoagulation and electro-Fenton methods.

    Science.gov (United States)

    Yavuz, Yusuf; Shahbazi, Reza; Koparal, A Savaş; Öğütveren, Ulker Bakır

    2014-01-01

    The aim of this study is the treatment of Basic Red 29 (BR29) dye solution using hybrid iron-aluminum electrodes by electrocoagulation and electro-Fenton methods. The effect of current density, initial pH, supporting electrolyte, H₂O₂, and initial dye concentration on dye removal efficiency was investigated, and the best experimental conditions were obtained. Time-coarse variation of UV-Vis spectra and toxicity and chemical oxygen demand (COD) removal were also examined at the best experimental conditions. Both systems were found very successful for the removal of BR29 dye. The removal efficiency of >95% for BR29 dye solution was reached easily in a short time. At the best experimental conditions, for the initial BR29 concentration of 100 mg/L, >95% BR29 dye and 71.43% COD removal were obtained after 20 and 40 min of electrolysis, respectively. Additionally, toxicity results for electro-Fenton treatment of 100 mg/L BR29 were also very promising. According to the results obtained, although electro-Fenton is more effective, both systems can be used successfully to treat textile wastewater including dyes. PMID:24687790

  19. Tubular carbon nanotube-based gas diffusion electrode removes persistent organic pollutants by a cyclic adsorption - Electro-Fenton process.

    Science.gov (United States)

    Roth, Hannah; Gendel, Youri; Buzatu, Pompilia; David, Oana; Wessling, Matthias

    2016-04-15

    We report a novel tubular electrochemical cell which is operated in a cyclic adsorption - electro-Fenton process and by this means overcomes the drawbacks of the traditional electro-Fenton process. A microtube made only of multi-walled carbon nanotubes (MWCNT) functions as a gas diffusion electrode (GDE) and highly porous adsorber. In the process, the pollutants were first removed electroless from the wastewater by adsorption on the MWCNT-GDE. Subsequently, the pollutants are electrochemically degraded in a defined volume of electrolyte solution using the electro-Fenton process. Oxygen was supplied into the lumen of the saturated microtubular GDE which was surrounded by a cylindrical anode made of Ti-felt coated with Pt/IrO2 catalysts. For the proof of concept the model pollutant Acid Red 14 (AR14), an azo dye, was used. The decomposition of AR14 was studied at different applied current densities and initial concentrations of ferrous iron in the electrolyte solution. At optimal conditions, complete regeneration of the adsorption capacity of the MWCNT-GDE, complete decolorization and TOC and COD removal rates of 50% and 70% were achieved, respectively. The MWCNT-GDE is regenerated and again available for adsorption. This approach allows water treatment independent of its composition, thus does not require any addition of chemicals to the wastewater. PMID:26775104

  20. Fate of thiabendazole through the treatment of a simulated agro-food industrial effluent by combined MBR/Fenton processes at μg/L scale.

    Science.gov (United States)

    Sánchez Peréz, J A; Carra, I; Sirtori, C; Agüera, A; Esteban, B

    2014-03-15

    This study has been carried out to assess the performance of a combined system consisting of a membrane bioreactor (MBR) followed by an advanced oxidation process (Fenton/Photo-Fenton) for removing the fungicide thiabendazole (TBZ) in a simulated agro-food industrial wastewater. Previous studies have shown the presence of TBZ in the effluent of an agro-food industry treated by activated sludge in a sequencing batch reactor (SBR), thus reinforcing the need for alternative treatments for removal. In this study, a simulated agro-food industry effluent was enriched with 100 μg L(-1) TBZ and treated by combined MBR/Fenton and MBR/solar photo-Fenton systems. Samples were directly injected into a highly sensitive liquid chromatography-triple quadrupole-linear ion trap-mass spectrometer (LC-QqLiT-MS/MS) analytical system to monitor the degradation of TBZ even at low concentration levels (ng L(-1)). Results showed that the biological treatment applied was not effective in TBZ degradation, which remained almost unaltered; although most dissolved organic matter was biodegraded effectively. Fenton and solar photo-Fenton, were assayed as tertiary treatments. The experiments were run without any pH adjustment by using an iron dosage strategy in the presence of excess hydrogen peroxide. Both treatments resulted in a total degradation of TBZ, obtaining more than 99% removal in both cases. To assure the total elimination of contaminants in the treated waters, transformation products (TPs) of TBZ generated during Fenton degradation experiments were identified and monitored by liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-QTOF-MS/MS). Up to four TPs could be identified. Two of them corresponded to mono-hydroxylated derivatives, typically generated under hydroxyl radicals driven processes. The other two corresponded with the hydrolysis of the TBZ molecule to yield benzoimidazole and thiazole-4-carboxamidine. All of them were also degraded during the

  1. Degradation of 32 emergent contaminants by UV and neutral photo-fenton in domestic wastewater effluent previously treated by activated sludge.

    Science.gov (United States)

    De la Cruz, N; Giménez, J; Esplugas, S; Grandjean, D; de Alencastro, L F; Pulgarín, C

    2012-04-15

    This study focuses on the removal of 32 selected micropollutants (pharmaceuticals, corrosion inhibitors and biocides/pesticides) found in an effluent coming from a municipal wastewater treatment plant (MWTP) based on activated sludge. Dissolved organic matter was present, with an initial total organic carbon of 15.9 mg L(-1), and a real global quantity of micropollutants of 29.5 μg L(-1). The treatments tested on the micropollutants removal were: UV-light emitting at 254 nm (UV(254)) alone, dark Fenton (Fe(2+,3+)/H(2)O(2)) and photo-Fenton (Fe(2+,3+)/H(2)O(2)/light). Different irradiation sources were used for the photo-Fenton experiences: UV(254) and simulated sunlight. Iron and H(2)O(2) concentrations were also changed in photo-Fenton experiences in order to evaluate its influence on the degradation. All the experiments were developed at natural pH, near neutral. Photo-Fenton treatments employing UV(254), 50 mg L(-1) of H(2)O(2), with and without adding iron (5 mg L(-1) of Fe(2+) added or 1.48 mg L(-1) of total iron already present) gave the best results. Global percentages of micropollutants removal achieved were 98 and a 97% respectively, after 30 min of treatments. As the H(2)O(2) concentration increased (10, 25 and 50 mg L(-1)), best degradations were observed. UV(254), Fenton, and photo-Fenton under simulated sunlight gave less promising results with lower percentages of removal. The highlight of this paper is to point out the possibility of the micropollutants degradation in spite the presence of DOM in much higher concentrations. PMID:22305640

  2. Avaliação da microfiltração para remoção do lodo gerado no processo oxidativo avançado empregando o reagente de Fenton no tratamento de lixiviado de aterro sanitário Evaluation of microfiltration for removal of sludge generated in advanced oxidation process by Fenton reagent in treatment of landfill leachate

    OpenAIRE

    Wagner Guadagnin Moravia; Liséte Celina Lange; Míriam Cristina Santos Amaral

    2011-01-01

    Uma alternativa atrativa para o tratamento de lixiviado de aterro sanitário são os processos oxidativos avançados empregando o reagente de Fenton (POA/Fenton). No entanto, a aplicação do POA/Fenton é limitada pela geração de lodo no processo. Esse lodo possui elevada concentração de ferro, o que torna necessária sua separação do efluente tratado. O objetivo desse trabalho foi avaliar a microfiltração para a remoção de lodo gerado no POA/Fenton. A pesquisa foi desenvolvida em unidade de bancad...

  3. Destruction of Ion-Exchange Resin In Waste From the HFIR, T1 and T2 Tanks Using Fenton's Reagent

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, P.A.

    2002-11-06

    The use of Fenton's reagent (hydrogen peroxide and a ferrous iron catalyst) has been tested as a method for destroying ion-exchange resin in radioactive waste from three underground storage tanks at the Oak Ridge National Laboratory. The resin in these wastes must be destroyed before they can be transferred to the Melton Valley Storage Tanks (MVSTs) prior to solidification and disposal at the Waste Isolation Pilot Plant. The reaction with ion-exchange resin requires a dilute acidic solution (pH = 3 to 5) and moderate temperatures (T = 60 to 100 C). Laboratory-scale tests of the process have been successfully completed using both simulants and actual waste samples. The ion-exchange resin is oxidized to carbon dioxide and inorganic salts. The reaction rate is quite slow for temperatures below 70 C but increases almost linearly as the temperature of the slurry increases from 70 to 90 C. Pilot-scale tests have demonstrated the process using larger samples of actual waste slurries. A sample from the High Flux Isotope Reactor (HFIR) tank, containing 500 mL of settled solids (resin and inorganic sludge) in a total volume of 1800 mL, was successfully treated to meet MVST waste acceptance requirements in 9 h of processing time, using 1650 mL of 50 wt% hydrogen peroxide. A composite sample from the T1 and T2 tanks, which contained 1000 mL of settled solids in a total volume of 2000 mL required 8 h of treatment, using 1540 mL of 50 wt% peroxide, to meet waste acceptance requirements. Hydrogen peroxide reaction rates were 0.71 to 0.74 g H{sub 2}O{sub 2}/L/min, with very low (<2000 mg/L) concentrations of peroxide in the slurry. The reaction produces mostly carbon dioxide gas during the early part of the treatment, when organic carbon concentrations in the slurry are high, and then produces increasing amounts of oxygen as the organic carbon concentration drops. Small amounts (<3 vol%) of carbon monoxide are also generated. The off-gas from the pilot-scale tests, which was

  4. Ex Vivo Antioxidant Activity of Selected Medicinal Plants against Fenton Reaction-Mediated Oxidation of Biological Lipid Substrates

    OpenAIRE

    Namratha Pai Kotebagilu; Vanitha Reddy Palvai; Asna Urooj

    2015-01-01

    Free radical-mediated oxidation is often linked to various degenerative diseases. Biological substrates with lipids as major components are susceptible to oxygen-derived lipid peroxidation due to their composition. Lipid peroxide products act as biomarkers in evaluating the antioxidant potential of various plants and functional foods. The study focused on evaluation of the antioxidant potential of two extracts (methanol and 80% methanol) of four medicinal plants, Andrographis paniculata, Cost...

  5. Experimental Design of Photo-Fenton Reactions for the Treatment of Car Wash Wastewater Effluents by Response Surface Methodological Analysis

    OpenAIRE

    Tony, Maha A.; Zeinab Bedri

    2014-01-01

    Establishing a treatment process for practical and economic disposal of car wash wastewater has become an urgent environmental concern. Photo-Fenton’s process as one of the advanced oxidation processes is a potentially useful oxidation process in treating such wastewater. Lab-scale experiments with UV source, coupled with Fenton’s reagent, showed that hydrocarbon oil is degradable through such a process. The feasibility of photo-Fenton’s process to treat wastewater from a car wash is investig...

  6. Quinolinic Acid - Iron(II) Complexes: Slow Autoxidation, but Enhanced Hydroxyl Radical Production in the Fenton Reaction

    Czech Academy of Sciences Publication Activity Database

    Pláteník, J.; Stopka, Pavel; Vejražka, M.; Štípek, S.

    2001-01-01

    Roč. 34, č. 5 (2001), s. 445-459. ISSN 1071-5762 R&D Projects: GA ČR GA203/97/0642; GA ČR GA309/99/0211 Institutional research plan: CEZ:AV0Z4032918 Keywords : iron chelator * reactive oxygen species * excitotoxicity Subject RIV: CA - Inorganic Chemistry Impact factor: 2.735, year: 2001

  7. Fenton试剂强化微电解工艺预处理中纤板热磨废水%Micro-electrolysis treatment for hot, grinding wastewater from MDF production using Fenton's reagent

    Institute of Scientific and Technical Information of China (English)

    张文妍; 李凡; 孙盼华; 张齐生

    2011-01-01

    The hot, grinding wastewater from medium density fiberboard (MDF) production contains high concentrated toxic oranic maters. It is not fit for biochemical treatment even after pretreatment of micro-electrolysis. Fenton's reagent method was employed to improve the former micro-electrolysis treatment by means of jar test. Optimal parameters of the Fenton process were determined as 0.05-0.10 of [Fe2+]/[H2O2] with 1 h reaction time. When Fenton treated effluent was controlled at pH 8.5, the sedimentation process further removed pollutants, and the chemical oxygen demand (COD) concentration of the former micro-electrolysis treatment effluent was reduced from 14 000 mg· L-1 to about 3 500 mg·L-1 . GC-MS analysis indicated that the combined process of micro-electrolysis and Fenton oxidation broke almost all of the monocyclic terpene bonds in the wastewater, oxidizing them to esters, alcohols, and ketones with a lower carbon number. However, for double ring terpense the combined process only broke some of the bonds. These obtained results evidenced the efficiency of the combined process to the hot, grinding wastewater pretreatment and should contribute to further studies of MDF wastewater treatment. [Ch, 5 fig. 1 tab. 13 ref.]%研究了Fenton试剂强化微电解工艺预处理中纤板热磨废水的效果.结果表明,保持废水中亚铁离子(Fe2+)和过氧化氢(H2O2)的摩尔比为0.05~0.10,反应30 min后将废水pH值调到8.5,可进一步将微电解出水的化学需氧量值从14 000 mg·L-1降低到3 500mg·L-1左右,大幅提升了预处理的效果,并为后续的生化处理提供良好的基础.另外,对热磨废水和最终出水进行了气相色谱/质谱联用技术(GC-MS)分析,结果显示,微电解-Fenton氧化工艺的氧化能力可以打开所有热磨废水中单环萜烯的键,将它们氧化成低碳原子的酯类、醇类和酮类化合物,但还不足以将废水中所有双环萜烯的键打开.图5表1参13

  8. Minimization of organic content in simulated industrial wastewater by Fenton type processes: a case study.

    Science.gov (United States)

    Grcić, Ivana; Vujević, Dinko; Sepcić, Josip; Koprivanac, Natalija

    2009-10-30

    Pre-treatment of simulated industrial wastewaters (SIM1, SIM2 and SIM3) containing organic and inorganic compounds (1,2-dichloroethane, sodium formate, sodium hydrogen carbonate, sodium carbonate and sodium chloride) by oxidative degradation using homogeneous Fenton type processes (Fe2+/H2O2 and Fe3+/H2O2) has been evaluated. The effects of initial Fe2+ and Fe3+ concentrations, [Fe2+/3+], type of iron salt (ferrous sulfate vs. ferric chloride), initial hydrogen peroxide concentration, [H2O2], on mineralization extent, i.e., total organic content (TOC) removal, were studied. Response surface methodology (RSM), particularly Box-Behnken design (BBD) was used as modelling tool, and obtained predictive function was used to optimize the overall process by the means of desirability function approach (DFA). Up to 94% of initial TOC was removed after 120 min. Ferrous sulfate was found to be the most appropriate reagent, and the optimal doses of Fe2+ and H2O2 for reducing the pollutant content, in terms of final TOC and sludge production were assessed. PMID:19525062

  9. Water quality in the vicinity of Fenton Hill, 1985 and 1986: Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Purtymun, W.D.; Ferenbaugh, R.W.; Williams, M.C.; Maes, M.N.

    1988-03-01

    Water quality data have been collected since 1974 from established surface and groundwater stations at and in the vicinity of Fenton Hill (Hot Dry Rock Geothermal Demonstration Site) located in the Jemez Mountains. This is part of a continuing program of environmental studies. Data on chemical quality of water were determined for samples collected from 13 surface water and 19 groundwater stations in 1985 and 1986. There were slight variations in the chemical quality of the ground and surface water in 1985 and 1986 as compared with previous analyses; however, these variations are within normal seasonal fluctuations. Chemical uptake in soil, roots, and foliage is monitored in the canyon, which receives intermittent effluent release of water from tests in the geothermal circulation loop and occasional fluids from drilling operations. The chemical concentrations found in soil, roots, and vegetation as the result of effluent release have shown a decrease in concentration down-canyon and also have decreased in concentration with time since the larger releases that took place in the late 1970s and early 1980s. 18 refs., 7 figs., 9 tabs.

  10. Degradation of the antibiotic amoxicillin by photo-Fenton process--chemical and toxicological assessment.

    Science.gov (United States)

    Trovó, Alam G; Nogueira, Raquel F Pupo; Agüera, Ana; Fernandez-Alba, Amadeo R; Malato, Sixto

    2011-01-01

    The influence of iron species on amoxicillin (AMX) degradation, intermediate products generated and toxicity during the photo-Fenton process using a solar simulator were evaluated in this work. The AMX degradation was favored in the presence of the potassium ferrioxalate complex (FeOx) when compared to FeSO(4). Total oxidation of AMX in the presence of FeOx was obtained after 5 min, while 15 min were necessary using FeSO(4). The results obtained with Daphnia magna biossays showed that the toxicity decreased from 65 to 5% after 90 min of irradiation in the presence of FeSO(4). However, it increased again to a maximum of 100% after 150 min, what indicates the generation of more toxic intermediates than AMX, reaching 45% after 240 min. However, using FeOx, the inhibition of mobility varied between 100 and 70% during treatment, probably due to the presence of oxalate, which is toxic to the neonates. After 240 min, between 73 and 81% TOC removal was observed. Different pathways of AMX degradation were suggested including the opening of the four-membered β-lactamic ring and further oxidations of the methyl group to aldehyde and/or hydroxylation of the benzoic ring, generating other intermediates after bound cleavage between different atoms and further oxidation to carboxylates such acetate, oxalate and propionate, besides the generation of nitrate and ammonium. PMID:21093887

  11. Applicability of Fenton Process for Treatment of Industrial Effluents: A Review

    Directory of Open Access Journals (Sweden)

    Mehali Mehta

    2014-12-01

    Full Text Available Wastewater and effluent treatment has undergone innovative changes over the years. Traditional wastewater treatment has yielded to modern and path-breaking procedures which are more efficient and effective. The world of difficulties and unknown has opened new avenues and paths to highly feasible effluent treatment procedures, so the vigorous importance of advanced oxidation procedures. This review paper will delineate the increasing importance of various advanced oxidation processes including Fenton treatment for wastewater. Advanced oxidation processes (AOP’s, which involve and includes the in-situ generation of highly potent chemical oxidants such as the hydroxyl radical, have emerged as an important avenue of technologies to accelerate the non-selective oxidation and thus the destruction of a wide range of non-degradable organic contaminants in wastewater which cannot be eliminated biologically. Advanced oxidation processes (AOP are technologies based on the generation of highly reactive species, the hydroxyl radicals, used in oxidative degradation procedures for organic compounds dissolved or dispersed in aquatic media. These processes are promising alternatives for decontamination of media containing dissolved recalcitrant organic substances, which would not be efficiently removed by conventional methods.

  12. Solar photo-Fenton like using persulphate for carbamazepine removal from domestic wastewater.

    Science.gov (United States)

    Ahmed, Moussa Mahdi; Chiron, Serge

    2014-01-01

    This work aimed at decontaminating biologically treated domestic wastewater effluent from pharmaceutical residues by using sulphate radical based homogeneous photo-Fenton involving persulphate (PS) as an oxidant, ferrous iron (Fe(II)) as a catalyst and simulated solar irradiation as a light source. This is the first time that the beneficiary use of solar energy in PS/Fe(II)/UV-Vis system was evaluated by using carbamazepine (CBZ) as a probe compound. In wastewater, CBZ was fully degraded in 30 min for an initial CBZ concentration of 50 μM and an optimal PS:Fe(II) molar ratio of 2:1 thanks to the high selectivity in reactivity of the sulphate radical limiting scavenging effects of organic matter and inorganic ions. Seventeen by-products were identified using liquid chromatography-high resolution-mass spectrometry allowing for the establishment of degradation pathways. CBZ first underwent degradation through one electron transfer oxidation processes due to sulphate radical reactivity followed by hydroxylation processes through hydroxyl radical formed by Fe(III) photoreduction. The sequential generation of sulphate radical and hydroxyl radical has made PS/Fe(II)/UV-Vis a kinetically effective process in removing CBZ from wastewater without the accumulation of toxic intermediates and opens new remediation strategies for tertiary treatment in domestic wastewater treatment plants. PMID:24095595

  13. Aquatic toxicity of dyes before and after photo-Fenton treatment.

    Science.gov (United States)

    de Luna, Luis A V; da Silva, Thiago H G; Nogueira, Raquel F Pupo; Kummrow, Fábio; Umbuzeiro, Gisela A

    2014-07-15

    This study evaluated the ecotoxicity of five dyes to freshwater organisms before and during their photo-Fenton degradation. EC50 (48h) of the five tested dyes ranged from of 6.9 to >1000mgL(-1) for Daphnia similis. In the chronic tests IC50 (72h) varied from 65 to >100mgL(-1) for Pseudokirchneriella subcapitata and IC50 (8 days) from 0.5 to 410mgL(-1) for Ceriodaphnia dubia. Toxicity tests revealed that although the applied treatment was effective for decolorization of the dye, the partial mineralization may be responsible for the presence of degradation products which can be either more toxic than the original dye, as is the case of Vat Green 3 and Reactive Black 5, lead to initially toxic products which may be further degraded to non toxic products (acid Orange 7 and Food Red 17), or generate non toxic products as in the case of Food Yellow 3. The results highlighted the importance of assessing both acute and chronic toxicity tests of treated sample before effluent discharge. PMID:24910910

  14. Degradation of hydroxycinnamic acid mixtures in aqueous sucrose solutions by the Fenton process.

    Science.gov (United States)

    Nguyen, Danny M T; Zhang, Zhanying; Doherty, William O S

    2015-02-11

    The degradation efficiencies and behaviors of caffeic acid (CaA), p-coumaric acid (pCoA), and ferulic acid (FeA) in aqueous sucrose solutions containing the mixture of these hydroxycinnamic acids (HCAs) were studied by the Fenton oxidation process. Central composite design and multiresponse surface methodology were used to evaluate and optimize the interactive effects of process parameters. Four quadratic polynomial models were developed for the degradation of each individual acid in the mixture and the total HCAs degraded. Sucrose was the most influential parameter that significantly affected the total amount of HCA degraded. Under the conditions studied there was a analysis showed goodness of fit between the experimental results and the predicted values. The degradation behavior of CaA differed from those of pCoA and FeA, where further CaA degradation is observed at increasing sucrose and decreasing solution pH. The differences (established using UV/vis and ATR-FTIR spectroscopy) were because, unlike the other acids, CaA formed a complex with Fe(III) or with Fe(III) hydrogen-bonded to sucrose and coprecipitated with lepidocrocite, an iron oxyhydroxide. PMID:25585639

  15. Reduction of COD in wastewater from an organized tannery industrial region by Electro-Fenton process

    Energy Technology Data Exchange (ETDEWEB)

    Kurt, Ugur [Yildiz Technical University, Environmental Engineering Department, 34349 Istanbul (Turkey)]. E-mail: ukurt@yildiz.edu.tr; Apaydin, Omer [Yildiz Technical University, Environmental Engineering Department, 34349 Istanbul (Turkey)]. E-mail: apaydin@yildiz.edu.tr; Gonullu, M. Talha [Yildiz Technical University, Environmental Engineering Department, 34349 Istanbul (Turkey)]. E-mail: gonul@yildiz.edu.tr

    2007-05-08

    Advanced oxidation processes (AOPs) have led the way in the treatment of aqueous waste and are rapidly becoming the chosen technology for many applications. In this paper, COD reduction potential of leather tanning industry wastewaters by Electro-Fenton (EF) oxidation, as one of the AOPs, was experimentally evaluated. The wastewater sample was taken from an outlet of an equalization basin in a common treatment plant of an organized tannery industrial region in Istanbul, Turkey. Treatment of the wastewater was carried out by an electrochemical batch reactor equipped with two iron electrodes, which were connected parallel to each other. The oxidation process was studied for optimization of H{sub 2}O{sub 2} and the electricity consumptions were observed at different contact times under different pH conditions (3.0, 5.0 and 7.2). In each case, electricity consumption for decreased COD mass was estimated. In this process, COD was reduced by 60-70% within 10 min. By taking into consideration the local sewerage discharge limit, applicability of EF process for the tannery wastewaters was evaluated.

  16. Reduction of COD in wastewater from an organized tannery industrial region by Electro-Fenton process

    International Nuclear Information System (INIS)

    Advanced oxidation processes (AOPs) have led the way in the treatment of aqueous waste and are rapidly becoming the chosen technology for many applications. In this paper, COD reduction potential of leather tanning industry wastewaters by Electro-Fenton (EF) oxidation, as one of the AOPs, was experimentally evaluated. The wastewater sample was taken from an outlet of an equalization basin in a common treatment plant of an organized tannery industrial region in Istanbul, Turkey. Treatment of the wastewater was carried out by an electrochemical batch reactor equipped with two iron electrodes, which were connected parallel to each other. The oxidation process was studied for optimization of H2O2 and the electricity consumptions were observed at different contact times under different pH conditions (3.0, 5.0 and 7.2). In each case, electricity consumption for decreased COD mass was estimated. In this process, COD was reduced by 60-70% within 10 min. By taking into consideration the local sewerage discharge limit, applicability of EF process for the tannery wastewaters was evaluated

  17. A Comparison of Central Composite Design and Taguchi Method for Optimizing Fenton Process

    Directory of Open Access Journals (Sweden)

    Anam Asghar

    2014-01-01

    Full Text Available In the present study, a comparison of central composite design (CCD and Taguchi method was established for Fenton oxidation. Dyeini, Dye : Fe+2, H2O2 : Fe+2, and pH were identified control variables while COD and decolorization efficiency were selected responses. L9 orthogonal array and face-centered CCD were used for the experimental design. Maximum 99% decolorization and 80% COD removal efficiency were obtained under optimum conditions. R squared values of 0.97 and 0.95 for CCD and Taguchi method, respectively, indicate that both models are statistically significant and are in well agreement with each other. Furthermore, Prob > F less than 0.0500 and ANOVA results indicate the good fitting of selected model with experimental results. Nevertheless, possibility of ranking of input variables in terms of percent contribution to the response value has made Taguchi method a suitable approach for scrutinizing the operating parameters. For present case, pH with percent contribution of 87.62% and 66.2% was ranked as the most contributing and significant factor. This finding of Taguchi method was also verified by 3D contour plots of CCD. Therefore, from this comparative study, it is concluded that Taguchi method with 9 experimental runs and simple interaction plots is a suitable alternative to CCD for several chemical engineering applications.

  18. Degradation of phenol with using of Fenton-like Processes from water

    Directory of Open Access Journals (Sweden)

    Ahmad Reza Yazdanbakhsh

    2015-08-01

    Full Text Available Phenol is one of the serious pollutants from the chemical and petrochemical industries. This pollutant due to its convoluted structure is resistant to biodegradation. One of the methods that are useful to remove this pollutant is advanced oxidation (AOP. A laboratory scale study was done on a synthetic wastewater containing phenol. All experiments were done in batch conditions and effect of variables pH, amount of hydrogen peroxide, iron dosage, contact time and an initial concentration on the phenol removal were tested. The remaining phenol concentration was evaluated using the DR-5000 device. In order to effect of these parameters, the experiment was performance at pH 2 to 6, 5 to 45 ml/ml of peroxide, and time of 5 to 60 minutes with 2 to 15 g/ml iron (Fe˚. The optimum pH, the ratio of hydrogen, Fe˚and time were 3, 15 ml, 8g and 5 minutes respectively. Chemical oxygen demand (COD index was chosen as the parameter for evaluation in this study. Result showed that mineralization of phenol was not complete. The COD removal efficiency was obtained 71%. According to the results of this study, Fenton-like process can be used for conversion organic resistant compounds to other compounds with lower toxicity.

  19. Sono-advanced Fenton decolorization of azo dye Orange G: Analysis of synergistic effect and mechanisms.

    Science.gov (United States)

    Cai, Meiqiang; Su, Jie; Lian, Guanghu; Wei, Xiaoqin; Dong, Chunying; Zhang, Haojie; Jin, Micong; Wei, Zongsu

    2016-07-01

    In this study, a successful decolorization of Orange G was achieved by means of coupling zero valent iron (ZVI), H2O2 and ultrasound (US) under acidic pH conditions. The synergistic effect and characterization of potential roles of the factors including ZVI, tert-Butanol as radical scavenger, dissolved ferrous ions and H2O2 generated from sonication were evaluated in this sono-advanced Fenton process (SAFP) system. A clear synergy was evident in terms of decolorization rate and the TOC removal as the input of US enhanced the activity of the Fe(0)/H2O2 system. The results suggested that the ZVI was potential replacement for the Fe(2+) ion. This remarkable activity was attributed to the capacity of Fe(2+) formed and reduction of sonic-dissolved Fe(2+) concentration by the formation of {Fe·Fe(2+)}. The modification of the condition of H2O2 addition such as the dosage and input method showed significant variations in terms of decolorization rate. This result indicated that the optimal external addition of H2O2 and input method is a limited factor of decolorization rate due to its comparatively insufficient generated by ultrasound. PMID:26964940

  20. Oxidation of disinfectants with Cl-substituted structure by a Fenton-like system Cu(2+)/H2O2 and analysis on their structure-reactivity relationship.

    Science.gov (United States)

    Peng, Jianbiao; Li, Jianhua; Shi, Huanhuan; Wang, Zunyao; Gao, Shixiang

    2016-01-01

    As widely used chemicals intended to protect human being from infection of microorganisms, disinfectants are ubiquitous in the environment. Among them chlorine-substituted phenol is a basic structure in many disinfectant molecules. Removal of these pollutants from wastewater is of great concern. The oxidative degradation of antimicrobial agents such as triclosan, chlorofene, and dichlorofene by a Fenton-like system Cu(2+)/H2O2 was examined. Reaction conditions such as temperature, initial concentrations of H2O2 and Cu(2+), and pH were optimized using triclosan as a representative. The degradation kinetics of the above disinfectants followed pseudo-first-order kinetics under the investigated conditions. Fourteen chlorophenols (CPs) with different chlorine substitution were also studied to evaluate the influence of molecular structure on the degradation process in the Cu(2+)/H2O2 system. Fourteen structure-related parameters were calculated using Gaussian 09 program. A quantitative structure-activity relationship (QSAR) model was established using SPSS software with measured rate constant (k) as dependent variable and calculated molecular descriptors as independent variables. A three-parameter model including energy of HOMO (E homo), molar heat capacity at constant volume (Cv(θ)), and the most positive net charge of hydrogen atoms (qH(+)) was selected for k prediction, with correlation coefficient R(2) = 0.878. Analyses of the model demonstrated that the Cv(θ) was the most significant factor affecting the k of chlorophenols. Variance analysis and standard t-value test were used to validate the model. PMID:26408114

  1. Nanocasted synthesis of magnetic mesoporous iron cerium bimetal oxides (MMIC) as an efficient heterogeneous Fenton-like catalyst for oxidation of arsenite

    International Nuclear Information System (INIS)

    Highlights: • MMIC with large surface area and pore volume was synthesized via the hard template. • MMIC could be easily separated from aqueous solution with an external magnetic field. • MMIC presented excellent catalytic activity for the oxidation of As(III). • As(III) was mainly oxidized by surface-bound ·OHads and free ·OHfree radicals. • MMIC played a dual function role for the arsenic removal in aqueous solution. - Abstract: Magnetic mesoporous iron cerium bimetal oxides (MMIC) with large surface area and pore volume was synthesized via the hard template approach. This obtained MMIC was easily separated from aqueous solution with an external magnetic field and was proposed as a heterogeneous Fenton-like catalyst for oxidation of As(III). The MMIC presented excellent catalytic activity for the oxidation of As(III), achieving almost complete oxidation of 1000 ppb As(III) after 60 min and complete removal of arsenic species after 180 min with reaction conditions of 0.4 g/L catalyst, pH of 3.0 and 0.4 mM H2O2. Kinetics analysis showed that arsenic removal followed the pseudo-first order, and the pseudo-first-order rate constants increased from 0.0014 min−1 to 0.0548 min−1 as the H2O2 concentration increased from 0.04 mM to 0.4 mM. On the basis of the effects of XPS analysis and reactive oxidizing species, As(III) in aqueous solution was mainly oxidized by ·OH radicals, including the surface-bound ·OHads generated on the MMIC surface which were involved in ≡Fe2+ and ≡Ce3+, and free ·OHfree generation by soluble iron ions which were released from the MMIC into the bulk solution, and the generated As(V) was finally removed by MMIC through adsorption

  2. Application of response surface methodology for optimization of azocarmine B removal by heterogeneous photo-Fenton process using hydroxy-iron–aluminum pillared bentonite

    International Nuclear Information System (INIS)

    Hydroxy-iron–aluminum pillared bentonite (H-Fe–Al-B) was synthesized with ion exchange method, and its catalyst characteristics were analyzed by using X-ray diffraction (XRD) and X-ray photoelectron spectrometry (XPS). The photo-Fenton catalytic activity of H-Fe–Al-B was tested under different reaction condition using azocarmine B (ACB) as model pollutant under ultraviolet light (UV) irradiation. The effects of three operating variables, initial dye concentration, initial pH value and H2O2 concentration on the decolorization efficiency of ACB were optimized by response surface methodology (RSM) based on Box–Behnken design. The results showed that hydroxy aluminum iron ions intercalated into the interlayer spaces of bentonite successfully and H-Fe–Al-B had high photocatalytic activity. Analysis of variance (ANOVA) indicated that the proposed quadratic model could be used to navigate the design space. The proposed model was approximately in accordance with the experimental case with correlation coefficients R2, Radj2 and Rpred2 correlation coefficients of 0.9996, 0.9991 and 0.9934, respectively. The optimum conditions for ACB decolorization were dye concentration of 143.7 mg/L, pH of 4.2 and H2O2 concentration of 17.7 mM, respectively. The predicted decolorization rate under the optimum conditions determined by the proposed model was 99.6%. Confirmatory tests were carried out under the optimum conditions and the decolorization rate of 99.5% was observed, which closely agreed with the predicted value.

  3. Characterization of dissolved organic matter in landfill leachate during the combined treatment process of air stripping, Fenton, SBR and coagulation

    International Nuclear Information System (INIS)

    Highlights: • DOM fractions spectra analysis during the whole treatment process. • Efficient method was achieved to remove organic matters in landfill leachate. • Molecular weight distribution and fractions were discussed. - Abstract: A combined treatment process of air stripping + Fenton + sequencing batch reactor (SBR)+ coagulation was performed to remove the pollutants in landfill leachate. Molecular weight (MW) distribution and fractions of dissolved organic matter (DOM) were discussed to study the characteristics. The experiment showed that the removal rate of chemical oxygen demand (COD), five day biological oxygen demand (BOD5) and ammonia nitrogen (NH3−N) by the combined process were 92.8%, 87.8% and 98.0%, respectively. Humic acid (HA) and fulvic acid (FA) were the main fractions in raw leachate with 81.8% of the total COD concentration, while hydrophilic organic matter (HyI) was the dominant fraction in the final effluent of the combined process with 63.5% of the total COD concentration. After the combined treatment process, the removal rate of DOM and fractions HA, FA, HyI were 91.9%, 97.1%, 95.8% and 71.7%, respectively. Organic matters of MW < 2 k and MW > 100 k were removed with 90.5% and 97.9% COD concentration after the treatment. The ultraviolet–visible spectra (UV–vis), Fourier transform infrared spectra (FTIR) and three-dimensional excitation-emission matrices spectra (EEMs) indicated that benzene materials and phenol compounds were preferentially removed in air stripping. High MW matters, aromatic rings, conjugated moieties and some functional groups were mainly removed by Fenton. While small MW fractions, carboxylic acids, alcohols and protein-like materials were preferentially biodegraded via SBR. Fulvic-like and humic-like materials were mainly destroyed via Fenton oxidation and coagulation

  4. Characterization of dissolved organic matter in landfill leachate during the combined treatment process of air stripping, Fenton, SBR and coagulation

    Energy Technology Data Exchange (ETDEWEB)

    Liu, ZhiPing, E-mail: liulqs@163.com [Key Laboratory of Three Gorges Reservoir Region’s Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045 (China); Faculty of Urban Construction and Environmental Engineering, Chongqing University, Chongqing 400020 (China); Wu, WenHui; Shi, Ping [Faculty of Urban Construction and Environmental Engineering, Chongqing University, Chongqing 400020 (China); Guo, JinSong [Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400045 (China); Cheng, Jin [Faculty of Urban Construction and Environmental Engineering, Chongqing University, Chongqing 400020 (China)

    2015-07-15

    Highlights: • DOM fractions spectra analysis during the whole treatment process. • Efficient method was achieved to remove organic matters in landfill leachate. • Molecular weight distribution and fractions were discussed. - Abstract: A combined treatment process of air stripping + Fenton + sequencing batch reactor (SBR)+ coagulation was performed to remove the pollutants in landfill leachate. Molecular weight (MW) distribution and fractions of dissolved organic matter (DOM) were discussed to study the characteristics. The experiment showed that the removal rate of chemical oxygen demand (COD), five day biological oxygen demand (BOD{sub 5}) and ammonia nitrogen (NH{sub 3}−N) by the combined process were 92.8%, 87.8% and 98.0%, respectively. Humic acid (HA) and fulvic acid (FA) were the main fractions in raw leachate with 81.8% of the total COD concentration, while hydrophilic organic matter (HyI) was the dominant fraction in the final effluent of the combined process with 63.5% of the total COD concentration. After the combined treatment process, the removal rate of DOM and fractions HA, FA, HyI were 91.9%, 97.1%, 95.8% and 71.7%, respectively. Organic matters of MW < 2 k and MW > 100 k were removed with 90.5% and 97.9% COD concentration after the treatment. The ultraviolet–visible spectra (UV–vis), Fourier transform infrared spectra (FTIR) and three-dimensional excitation-emission matrices spectra (EEMs) indicated that benzene materials and phenol compounds were preferentially removed in air stripping. High MW matters, aromatic rings, conjugated moieties and some functional groups were mainly removed by Fenton. While small MW fractions, carboxylic acids, alcohols and protein-like materials were preferentially biodegraded via SBR. Fulvic-like and humic-like materials were mainly destroyed via Fenton oxidation and coagulation.

  5. Characterization and detoxification of a mature landfill leachate using a combined coagulation–flocculation/photo Fenton treatment

    International Nuclear Information System (INIS)

    Highlights: ► A mature landfill leachate was characterized in terms of its pollutants and toxicity. ► A toxicity bioassay revealed an antagonistic behavior among its pollutants. ► The coagulation stage produced good results for TC and lead at an acidic pH. ► The photo Fenton treatment yielded good COD, ammonia and lead removals. ► Arsenic and mercury showed low removal efficiencies throughout the treatment. - Abstract: The aim of the present work was to characterize and treat a mature landfill leachate using a coagulation/flocculation process followed by a photo-Fenton oxidation treatment. The leachate was obtained from a landfill in Tetlama, Morelos (Mexico) during the drought season and was characterized in terms of its major pollutants. Considerable levels of chemical oxygen demand (COD), total carbon (TC) and NH4+ were identified, as well as high concentrations of Hg, Pb, and As. Other heavy metals such as Ni, Co, Zn, Cd, and Mn were detected at trace levels. The lethal concentration (LC50) of the leachate, evaluated on Artemia salina, was 12,161 ± 11 mg/L of COD, demonstrating an antagonistic interaction among the leachate's components. The treatment of this effluent consisted of a coagulation–flocculation process using an optimal dose of FeCl3·6H2O of 300 mg/L. The supernatant was treated using a photo-Fenton process mediated with FeCl2·4H2O and H2O2 in a compound parabolic concentrator (CPC) photo-reactor operating in batch mode using an R ratio (R = [H2O2]/[Fe2+]) of 114. The global removal efficiencies after treatment were 56% for the COD, 95% for TC, and 64% for NH4+. The removal efficiencies for As, Hg, and Pb were 46%, 9%, and 85%, respectively.

  6. Fe(III/TiO2-Montmorillonite Photocatalyst in Photo-Fenton-Like Degradation of Methylene Blue

    Directory of Open Access Journals (Sweden)

    Is Fatimah

    2015-01-01

    Full Text Available A photodegradation process of methylene blue (MB in aqueous solution using Fe(III/TiO2-montmorillonite photocatalyst is presented. The photocatalyst material was prepared using Indonesian natural montmorillonite in TiO2 pillarization process followed by Fe(III ion exchange. Kinetic study on MB degradation was conducted and evaluated by three kinetic models: the pseudo-first- and second-order equations and the Elovich equation. From the results, it is concluded that the degradation under the photo-Fenton-like process utilizing Fe(III/TiO2-montmorillonite photocatalyst conformed to the Elovich kinetic model.

  7. Evaluación del método Fenton para tratamientos de aguas industriales en ingeniería

    OpenAIRE

    Avendaño P., Gerardo; Reyes G., Maritza

    2012-01-01

    Por parte de los sectores industrial y académico, existe un gran interés en el uso de alternativas económicas que posibiliten una degradación efectiva de la carga contaminante de las aguas residuales, sin producir efectos colaterales que trasladan el problema pero no lo resuelven. El método Fenton es un tratamiento químico para vertimientos industriales que se presenta en esta investigación como una nueva alternativa para el tratamiento de vertimientos industriales med...

  8. Synthesis for Magnetic Mesoporous Fe3O4-SiO2 Composites and Heterogeneous Fenton Degradation of Methyl Blue

    Science.gov (United States)

    Xie, Huanling; Zhang, Tengyun

    2014-12-01

    In this work, we presented a facile, one-step preparation for magnetic mesoporous Fe3O4-SiO2 composites under closely neutral conditions by an evaporation-induced self-assembly (EISA) and adding 1,3,5-TMB as co-solvent approach. The resulting samples were characterized by X-ray diffraction, N2 adsorption measurement, FT-IR and SEM. Magnetic mesoporous composites and H2O2 form heterogeneous Fenton in order to removal methylene blue as the dye wastewater model object. The catalysts showed high catalytic activity and stability in the decolorization of methlye blue.

  9. Humic Acid Degradation via Solar Photo-Fenton Process in Aqueous Environment

    Directory of Open Access Journals (Sweden)

    Seyed Ali Sajjadi

    2015-08-01

    Full Text Available Control of mutagenic and carcinogenic disinfection by-products, particularly Trihalomethanes (THMs and Halo Acetic Acids (HAAs in water treatment process is critical, due to their adverse effects on human health. Generally, reducing the toxicity of these by-products hinges on prior removal of the precursor materials, such as Humic Acid (HA in drinking water. This study was conducted to investigate the role of some parameters that could affect the removal of HA, including HA (5 and 10 ppm and H2O2 (20, 40, 60, and 80 ppm initial concentrations, Iron (II, sulfate heptahydrate dosage (4, 8, 12, and 16 ppm, pH (2, 3, 4 and 5, Oxidation time (5, 10, 15 and 30 min, and Sunlight levels (322±13 kWm-2. To accelerate the process of HA removal, the Solar Photo-Fenton (SPF process was employed by direct irradiation of converged sunlight in a Parabolic Trough Collectors (PTC, with 3m2 effective area. HA levels were measured via quantifying Dissolved Organic Carbon (DOC concentrations by means of a TOC Analyzer method. The results showed that the SPF process is under control of the Fe & H2O2 ratio, the Fe2+ dosage and especially the pH quantity. In optimal condition, (pH: 4, oxidation time: 30min, initial HA levels: 50 ppm, H2O2 concentrations: 20 ppm Fe+2 levels: 4 ppm, the study found more than 98% DOC removal. In conclusion, the SPF, as an economically effective technique, could be applied for the removal of HA in aqueous environments.

  10. How do Enzymes Utilize Reactive OH Radicals? Lessons from Nonheme HppE and Fenton Systems.

    Science.gov (United States)

    Wang, Binju; Lu, Jiarui; Dubey, Kshatresh Dutta; Dong, Geng; Lai, Wenzhen; Shaik, Sason

    2016-07-13

    The iron(IV)-oxo (ferryl) intermediate has been amply established as the principal oxidant in nonheme enzymes and the key player in C-H bond activations and functionalizations. In contrast to this status, our present QM/MM calculations of the mechanism of fosfomycin biosynthesis (a broad range antibiotic) by the nonheme HppE enzyme rule out the iron(IV)-oxo as the reactive species in the hydrogen abstraction (H-abstraction) step of the pro-R hydrogen from the (S)-2-hydroxypropylphosphonic substrate. Moreover, the study reveals that the ferryl species is bypassed in HppE, while the actual oxidant is an HO(•) radical hydrogen-bonded to a ferric-hydroxo complex, resulting via the homolytic dissociation of the hydrogen peroxide complex, Fe(II)-H2O2. The computed energy barrier of this pathway is 12.0 kcal/mol, in fair agreement with the experimental datum of 9.8 kcal/mol. An alternative mechanism involves the iron-complexed hydroxyl radical (Fe(III)-(HO(•))) that is obtained by protonation of the iron(IV)-oxo group via the O-H group of the substrate. The barrier for this pathway, 23.0 kcal/mol, is higher than the one in the first mechanism. In both mechanisms, the HO(•) radical is highly selective; its H-abstraction leading to the final cis-fosfomycin product. It appears that HppE is prone to usage of HO(•) radicals for C-H bond activation, because the ferryl oxidant requires a specific H-abstraction trajectory (∠FeOH ∼ 180°) that cannot be met for intramolecular H-abstraction. Thus, this work broadens the landscape of nonheme iron enzymes and makes a connection to Fenton chemistry, with implications on new potential biocatalysts that may harness hydroxyl radicals for C-H bond functionalizations. PMID:27309496

  11. Enhanced bioremediation of oil contaminated soil by graded modified Fenton oxidation

    Institute of Scientific and Technical Information of China (English)

    Jinlan Xu; Lei Xin; Tinglin Huang; Kun Chang

    2011-01-01

    Graded modified Fenton's (MF) oxidation is a strategy in which H2O2 is added intermittently to prevent a sharp temperature increase and undesired soil sterilization at soil circumneutral pH versus adding the same amount of H2O2 continuously.The primary objective of the present study was to investigate whether a mild MF pre-oxidation such as a stepwise addition of H2O2 can prevent sterilization and achieve a maximum degradation of tank oil in soil.Optimization experiments of graded MF oxidation were conducted using citric acid,oxalic acid and SOLV-X as iron chelators under different frequencies of H2O2 addition.The results indicated that the activity order of iron chelates decreased as:citric acid (51%) > SOLV-X (44%) > oxalic acid (9%),and citric acid was found to be an optimized iron chelating agent of graded MF oxidation.Three-time addition of H2O2 was found to be favorable and economical due to decreasing total petroleum hydrocarbon removal from three time addition (51%) to five time addition (59%).Biological experiments were conducted after graded MF oxidation of tank oil completed under optimum conditions mentioned above.After graded oxidation,substantially higher increase (31%) in microbial activity was observed with excessive H2O2 (1470 mmol,/L,the mol ratio of H2O2:Fe2+ was 210:1)than that of non-oxidized soil.Removal efficiency of tank oil was up to 93% after four weeks.Especially,the oil fraction (C10-C40) became more biodagradable after graded MF oxidation than its absence.Therefore,graded MF oxidation is a mild pretreatment to achieve an effective bioremediation of oil contaminated soil.

  12. Use of Fenton reagent combined with humic acids for the removal of PFOA from contaminated water.

    Science.gov (United States)

    Santos, Aurora; Rodríguez, Sergio; Pardo, Fernando; Romero, Arturo

    2016-09-01

    Perfluorinated compounds (PFCs) are receiving significant attention due to its global distribution, high persistence, and bioaccumulation properties. Among them, perfluorooctanoic acid (PFOA) is one of the most commonly found in the environment. The strong bond C-F in PFOA is extremely difficult to degrade, therefore advanced oxidation processes (AOPs) at room temperature and pressure are not able to oxidize them, as was noticed here using Fenton like reagent (FR) or persulfate (PS) at 25°C. On the contrary, by using persulfate activated by heat (100mM and T=70°C) a complete defluorination of PFOA 0.1mM was noticed after 18h, with a sequential degradation mechanism of losing one CF2 unit from PFOA and its intermediates (perfluoroheptanoic acid (PFHpA), perfluorohexanoic acid (PFHxA), perfluoropentanoic acid (PFPA) and perfluorobutanoic acid (PFBA)). Since this thermal treatment is not usually desirable from an economical point of view, alternative process has been tested. For this scope, a hybrid process is proposed in this work, by adding humic acid, HA, (600mgL(-1)) and FR, (165mM in H2O2 and 3mM in Fe(3+)) to the 0.1mM PFOA solution. It was found that the HA was oxidized by FR. PFOA was entrapped quantitatively and irreversibly during HA oxidation, resulting PFOA non-available to the aqueous phase. Oxidized HA with PFOA entrapped precipitates. Both, the leftover Fe(III) acting as a coagulant and neutral pH enhance the separation of this solid phase. The precipitation noticed by adding HA to the PFOA solution in absence of FR was negligible. PMID:26412418

  13. A DFT Study Toward the Reaction Mechanisms of TNT With Hydroxyl Radicals for Advanced Oxidation Processes.

    Science.gov (United States)

    He, Xi; Zeng, Qun; Zhou, Yang; Zeng, Qingxuan; Wei, Xianfeng; Zhang, Chaoyang

    2016-05-26

    The degradation pathway of environmental contaminant 2,4,6-trinitrotoluene (TNT) was investigated computationally at the SMD(Pauling)/M06-2X/6-311+G(d,p) level of theory. The dominant decomposition pathway of TNT → 4,6-dinitro-o-cresol → 4,6-dinitro-2-hydroxybenzylalcohol → 4,6-dinitro-2-hydroxybenzaldehyde was provided, and the corresponding predicted products and their distributions are in a good agreement with available experimental data on TNT degradation by Fenton reaction. It was shown that the mechanism of addition-elimination is crucial for this stage of the reaction. The reaction of H atom abstraction is a minor competing pathway. The details on transition states, intermediate radicals, and free energy surfaces for all proposed reactions are given and make up for a lack of experimental knowledge. PMID:27135259

  14. Fenton氧化工艺在处理炼化废水中苯酚的应用研究%Study on Treatment of Phenol in Petroleum Refining Industry Wastewater by Fenton Reagent

    Institute of Scientific and Technical Information of China (English)

    李锐

    2014-01-01

    通过正交实验和单因素实验探索了Fenton氧化炼化废水中苯酚的最佳工艺条件。实验结果表明,Fenton试剂处理苯酚废水时,各影响因素的作用大小顺序是:pH>反应温度>H2O2投加量>反应时间>FeSO4·7H2O投加量;最佳氧化反应条件为:pH=3.5,反应温度为20℃,H2O2投加量为12 mL·L-1,反应时间为30min,FeSO4·7H2O投加量为450 mg·L-1,此时废水中苯酚的去除率为89.26%,残余苯酚含量为11.76 mg·L-1。因此,用Fenton氧化法处理含苯酚废水是一种非常有效的方法。%Removal of phenol in petroleum refining industry wastewater by Fenton reagent oxidation was examined. The optimal operating conditions were determined by orthogonal experiments and single factor experiments.The ex-periment results indicated that the order of effects was pH>reaction temperature>H2 O2 dosage >reaction time>FeSO4 7H2O dosage.After 30min,the removal rate of phenol in petroleum refining industry wastewater reaches 89.26% and the residual phenol in wastewater is 11.76 mg·L-1 when pH value is 3.5,temperature is 20 ℃, H2 O2 and FeSO4 dosage is 12 mL·L-1 and 450mg/L,respectively.So it is a very effective way to treat petroleum refining industry wastewater containing phenol using Fenton method.

  15. Multistage treatment system for raw leachate from sanitary landfill combining biological nitrification-denitrification/solar photo-Fenton/biological processes, at a scale close to industrial--biodegradability enhancement and evolution profile of trace pollutants.

    Science.gov (United States)

    Silva, Tânia F C V; Silva, M Elisabete F; Cunha-Queda, A Cristina; Fonseca, Amélia; Saraiva, Isabel; Sousa, M A; Gonçalves, C; Alpendurada, M F; Boaventura, Rui A R; Vilar, Vítor J P

    2013-10-15

    A multistage treatment system, at a scale close to the industrial, was designed for the treatment of a mature raw landfill leachate, including: a) an activated sludge biological oxidation (ASBO), under aerobic and anoxic conditions; b) a solar photo-Fenton process, enhancing the bio-treated leachate biodegradability, with and without sludge removal after acidification; and c) a final polishing step, with further ASBO. The raw leachate was characterized by a high concentration of humic substances (HS) (1211 mg CHS/L), representing 39% of the dissolved organic carbon (DOC) content, and a high nitrogen content, mainly in the form of ammonium nitrogen (>3.8 g NH4(+)-N/L). In the first biological oxidation step, a 95% removal of total nitrogen and a 39% mineralization in terms of DOC were achieved, remaining only the recalcitrant fraction, mainly attributed to HS (57% of DOC). Under aerobic conditions, the highest nitrification rate obtained was 8.2 mg NH4(+)-N/h/g of volatile suspended solids (VSS), and under anoxic conditions, the maximum denitrification rate obtained was 5.8 mg (NO2(-)-N + NO3(-)-N)/h/g VSS, with a C/N consumption ratio of 2.4 mg CH3OH/mg (NO2(-)-N + NO3(-)-N). The precipitation of humic acids (37% of HS) after acidification of the bio-treated leachate corresponds to a 96% DOC abatement. The amount of UV energy and H2O2 consumption during the photo-Fenton reaction was 30% higher in the experiment without sludge removal and, consequently, the reaction velocity was 30% lower. The phototreatment process led to the depletion of HS >80%, of low-molecular-weight carboxylate anions >70% and other organic micropollutants, thus resulting in a total biodegradability increase of >70%. The second biological oxidation allowed to obtain a final treated leachate in compliance with legal discharge limits regarding water bodies (with the exception of sulfate ions), considering the experiment without sludge. Finally, the high efficiency of the overall treatment

  16. Effect of different carriers and operating parameters on degradation of flax wastewater by fluidized-bed Fenton process.

    Science.gov (United States)

    Chen, Mengtian; Ren, Hongqiang; Ding, Lili; Gao, Baotian

    2015-01-01

    This investigation evaluates the effectiveness of a fluidized-bed Fenton process in treating flax wastewater. Flax wastewater was taken from a paper-making factory in a secondary sedimentation tank effluent of a paper-making factory in Hebei. The performance of three carriers (SiO2, Al2O3, Fe2O3) used in the reactor was compared, and the effects of different operational conditions, and Fenton reagent concentrations were studied. Experimental results indicated that SiO2 was the most appropriate carrier in the system. The dose of Fe2+ and H2O2 was a significant operating factor in the degradation progress. The bed expansion was considered to be another factor influencing the treatment effect. Under the appropriate conditions (300 mg/L Fe2+, 600 mg/L H2O2, and 74.07 g/L SiO2 as the carrier, at pH=3, 50% bed expansion), the highest removal rate of total organic carbon (TOC) and color was 89% and 94%, respectively. The article also discussed the process of the colority removal of flax wastewater and the kinetics of TOC removal. PMID:26067494

  17. Heterogeneous photo-Fenton degradation of polyacrylamide in aqueous solution over Fe(III)-SiO2 catalyst

    International Nuclear Information System (INIS)

    This article presents preparation, characterization and evaluation of heterogeneous Fe(III)-SiO2 catalysts for the photo-Fenton degradation of polyacrylamide (PAM) in aqueous solution. Fe(III)-SiO2 catalysts are prepared by impregnation method with two iron salts as precursors, namely Fe(NO3)3 and FeSO4, and are characterized by Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) methods. The irradiated Fe(III)-SiO2 is complexed with 1,10-phenanthroline, then is measured by UV-vis-diffuse reflectance spectroscopy (UV-vis-DRS) and XPS to confirm the oxidation state of Fe in solid state. By investigating the photo-Fenton degradation of PAM in aqueous solution, the results indicate that Fe(III)-SiO2 catalysts exhibit an excellent photocatalytic activity in the degradation of PAM. Moreover, the precursor species and the OH-/Fe mole ratio affect the photocatalytic activity of Fe(III)-SiO2 catalysts to a certain extent. Finally, the amount of Fe ions leaching from the Fe(III)-SiO2 catalysts is much low

  18. Tratamento do lixiviado de aterro de resíduos sólidos urbanos por processo Fenton

    Directory of Open Access Journals (Sweden)

    Victor Wegner Maus

    2009-01-01

    Full Text Available O lixiviado gerado em aterros sanitários pela decomposição dos resíduos sólidos com presença de água de infiltração possuigrande potencial poluidor, devido à elevada concentração de substâncias tóxicas e a sua baixa biodegradabilidade. A coagulaçãoquímica pode ser uma alternativa para o tratamento de efluentes com essas características. O trabalho teve como objetivo avaliar aeficiência do processo Fenton no tratamento de lixiviado gerado em aterros sanitários de resíduos sólidos urbanos. As amostras delixiviado foram coletadas no aterro controlado do município de Santa Maria – RS. No experimento foram testados cincotratamentos com diferentes proporções de reagentes (H2O2 e FeSO4 TH2O2/FeSO4: T0,8, T2,0, T3,0, T4,0 e T6,0. Pelos resultados doexperimento com processo Fenton verifica-se uma eficiência média na remoção da demanda química de oxigênio (DQO de47,9%, na turbidez de 53,0% e na cor de 70,7%. Os valores médios da demanda bioquímica de oxigênio (DBO e dacondutividade elétrica aumentaram em 31,3% e 27,1%, respectivamente. No tratamento T0,8 constatou-se a maior remoção daDQO e o maior aumento da biodegradabilidade. O processo Fenton aplicado no tratamento de lixiviado reduz a DQO e aumenta aDBO, em outras palavras, aumenta a biodegradabilidade do efluente. Esse processo pode ser utilizado como pré-tratamento de umsistema biológico para efluentes de aterros sanitários.Abstract The leachate generated on sanitary landfill bysolid waste decomposition with rainfall water infiltration hashigh potential of pollution, due to high concentration oftoxic substances and low biodegradability. The chemistrycoagulation can be an alternative to treat effluents with thesecharacteristics. The work aimed to evaluate the efficiency ofFenton process in the treatment of leachate landfill fromurban solid waste. The leachate samples were collected fromthe controlled landfill of Santa Maria Council – RS. In theexperiment

  19. A Brief History With Lessons Learned From The Hot Dry Rock Geothermal Energy Program At Fenton Hill, New Mexico, USA

    Science.gov (United States)

    Kelkar, S.; Woldegabriel, G. W.; Rehfeldt, K. R.

    2009-12-01

    Important lessons were learned that continue to be relevant today from the world’s first successful demonstration of a Hot Dry Rock (HDR) system for extracting underground geothermal energy conducted at Fenton Hill, New Mexico. This experiment, conducted in hot, low-permeability, low-water context, crystalline basement rock was fundamentally different from the Enhanced Geothermal Systems (EGS) development currently underway at several sites in the U.S. and world. The HDR concept was developed in 1970’s at Los Alamos National Laboratory (LANL). Two HDR reservoirs with two wells each were created and tested at the Fenton Hill site. In spite of its proximity to the Valles caldera and the Rio Grande rift, geological information and heat-flow data were used successfully to select the Fenton Hill experimental site within a block of intact crystalline basement rocks. Deep crystalline basement rocks marginal to active fault/recent volcanic centers were good candidates for HDR systems: these rocks had high heat content, and low matrix permeability leading to low water losses. Reconnaissance surveys indicated significant potential HDR geothermal resources through out the USA. Drilling and completion operations in hot crystalline rocks were challenging requiring further R&D. Hydraulic stimulation activities were carried out successfully in deep, hot crystalline rocks. Logging tools and instruments were developed that could operate successfully in the ~250oC environment. Development of techniques and tools for microseismic data monitoring, analysis, and interpretation was found to be enormously valuable. It was found that the systematic process that should be followed in developing HDR reservoirs is to drill and stimulate the first well, use the microseismic data to locate the target zone, and then complete the additional wells. The largest fraction of the flow impedance was found to be near the production well. Combined interpretation of the pressure testing, microseismic

  20. Experiment of Struvite Precipitation-Fenton Processes for Mature Landfill Leachate Treatment%鸟粪石 Fenton氧化处理老龄垃圾渗滤液的试验

    Institute of Scientific and Technical Information of China (English)

    王杰; 颜智勇; 树龙; 谭秀益; 陈峻峰; 舒鹏

    2015-01-01

    The optimum conditions of combination of struvite precipitation and Fenton process to treat the landfill leachate were explored in this paper. The results show that the combined treatment process takes advantages of both methods. When the initial pH is 9. 5,molecular ratio of Mg2+∶PO3-4 ∶NH4+ is 1. 3∶1. 2∶1 and reaction time is 30 min by struvite precipitation;and when the initial pH is 3. 3,concentration of H2 O2 is 0. 03 mol/L,molecular ratio of H2 O2∶Fe2+ is 4∶1 and reaction time is 2 h by Fenton process,COD removal rate is 86. 68% and ammonia nitrogen removal rate is 92. 27%,which are apparently superior to the result of struvite precipitation (COD removal rate is about 85%,ammonia nitrogen removal rate is 15%~20%),the result of Fenton process (COD removal rate is about 55%,ammonia nitrogen removal rate is almost zero),as well as the result of the combination of two methods in reversed order (COD removal rate is around 40%,ammonia nitrogen removal rate is around 20%).%采用鸟粪石法与Fenton试剂氧化法联合处理垃圾渗滤液,探索了两种方法联合处理的最优条件。结果表明两种方法联合处理能很好地发挥各自的优势。鸟粪石法在初始pH为9.5、n(Mg2+)∶n(PO3-4)∶n(NH4+)=1.3∶1.2∶1、搅拌反应时间为30 min时,且Fenton试剂氧化法在初始pH为3.5、H2 O2投加量为0.03 mol/L、n(H2 O2)∶n(Fe2+)=4∶1、搅拌反应时间为2 h时,COD去除率达到86.68%,氨氮去除率达到92.27%。该处理效果明显优于单独采用鸟粪石法的处理效果(其氨氮去除率约85%、COD去除率为15%~20%)、单独采用Fenton试剂法的处理效果(其COD去除率约55%、氨氮去除率几乎为零)及两种方法顺序调换的处理效果(其COD去除率约40%、氨氮去除率约20%)。

  1. Evaluation of the efficiency of the photo Fenton disinfection of natural drinking water source during the rainy season in the Sahelian region

    Energy Technology Data Exchange (ETDEWEB)

    Ndounla, J., E-mail: juliette.ndounla@epfl.ch [Ecole Polytechnique Fédérale de Lausanne, Institute of Chemical Sciences and Engineering GPAO, Station 6, CH 1015 Lausanne (Switzerland); Institut International d' Ingénierie de l' Eau et de l' Environnement, Laboratoire Eau, Dépollution, Ecosystème et Santé (LEDES), 01 BP 594 Ouagadougou 01 (Burkina Faso); Pulgarin, C., E-mail: Cesar.pulgarin@epfl.ch [Ecole Polytechnique Fédérale de Lausanne, Institute of Chemical Sciences and Engineering GPAO, Station 6, CH 1015 Lausanne (Switzerland)

    2014-09-15

    The photo-disinfection of water from two different wells (W1, pH: 4.6–5.1 ± 0.02) and (W2 pH: 5.6–5.7 ± 0.02) was carried out during the rainy season at Ouagadougou–Burkina Faso, West Africa. The weather variation during the rainy season significantly affects the photo-disinfection processes (solar disinfection and photo-Fenton). The dilution of the water by rainwater highly affected the chemical composition of the wells' water used in this study; very low iron contents Compared to the ones recorded during the dry season were recorded in all water samples. Both photo-disinfection processes were used to treat 25 L of water in a compound parabolic collector (CPC). None of them have shown the total inactivation of both wild enteric bacteria strains (total coliforms/E. coli and Salmonella spp.) involved in the treatment. However, the total coliforms/E. coli strains were totally inactivated during the exposure under most of the photo-Fenton treatment. Also, the remaining strains, especially those of Salmonella spp. were achieved during the subsequent 24 h of dark storage under the action of the Fenton process. Under uniquely solar radiation, total inactivation was recorded only in the total coliforms/E. coli strains. The impact of the available irradiance on the efficiency of the photo-Fenton disinfection of natural water was highlighted during the exposure under high intermittent solar radiation. The impact of the HCO{sub 3}{sup −} concentration of both wells' water on the evolution of the pH during the photo-disinfection was recorded. Drastic decrease was noticed after the initial fast increase in presence of low HCO{sub 3}{sup −} concentration while a steady state was observed after the increase in presence of higher concentration. The redox activities of the nitrogen components of the water during both photo-disinfection processes have led to increased concentration of nitrite in all the cases and variations were noticed in that of nitrate and

  2. Effects of UV irradiation on humic acid removal by ozonation, Fenton and Fe{sup 0}/air treatment: THMFP and biotoxicity evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Ming-Chi [Department of Food Science, Central Taiwan University of Science and Technology, Taichung, Taiwan, ROC (China); Wang, Kai-sung; Hsiao, Tung-En; Lin, I.-Chen; Wu, Hui-Ju [Department of Public Health, Chung-Shan Medical University, Taichung 402, Taiwan, ROC (China); Wu, Yuh-Luan; Liu, Pey-Horng [Green Energy and Environment Research Laboratories, Industrial Technology Research Institute, Taiwan, ROC (China); Chang, Shih-Hsien, E-mail: shchang@csmu.edu.tw [Department of Public Health, Chung-Shan Medical University, Taichung 402, Taiwan, ROC (China); Department of Family and Community Medicine, Chung Shan Medical University Hospital, Taichung 402, Taiwan, ROC (China)

    2011-11-15

    Highlights: {yields} Fe{sup 0}/air rapidly and effectively removed HA within 9 min and its COD, biotoxicity and THMFP were low. {yields} THMFP of ozonation-treated solution was much higher than those of Fenton-treated and Fe{sup 0}/air-treated solutions. {yields} UV irradiation during ozonation and Fenton oxidation enhanced HA removal, but did not reduce the THMFP of the treated solutions. {yields} Fe{sup 0}/air treatment with UV irradiation obviously increased the THMFP of the treated solution. {yields} The relationship between biotoxicity and chloroform in the chlorinated solution was insignificant. - Abstract: Effects of UV irradiation on humic acid (HA) removal by Fe{sup 0}/air, ozonation and Fenton oxidation were investigated. The trihalomethane forming potential (THMFP) and toxicity of treated solutions were also evaluated. The experimental conditions were ozone of 21 mg min{sup -1}, H{sub 2}O{sub 2} of 8 x 10{sup -4} M, Fe{sup 0} of 20 g L{sup -1}, air flow of 5 L min{sup -1}, and UVC of 9 W. Results indicated that Fe{sup 0}/air rapidly removed HA color (>99%) and COD (90%) within 9 min. 51-81% of color and 43-50% of COD were removed by ozonation and Fenton oxidation after 60 min. Both UV enhanced ozone and Fenton oxidation removed HA, but the Fe{sup 0}/air process did not. Spectrum results showed all processes effectively diminished UV-vis spectra, except for ozonation. The THMFP of Fe{sup 0}/air-treated solution (114 {mu}g L{sup -1}) was much lower than those of Fenton- (226 {mu}g L{sup -1}) and ozonation-treated solutions (499 {mu}g L{sup -1}). Fe{sup 0}/air with UV irradiation obviously increased the THMFP of treated solution (502 {mu}g L{sup -1}). The toxicity results obtained from Vibrio fischeri light inhibition test indicated that the toxicity of Fe{sup 0}/air-treated solution (5%) was much lower than that of ozonation- (33%) and Fenton-treated solutions (31%). Chlorination increased the solution toxicity. The correlation between biotoxicity and

  3. Evaluation of the efficiency of the photo Fenton disinfection of natural drinking water source during the rainy season in the Sahelian region

    International Nuclear Information System (INIS)

    The photo-disinfection of water from two different wells (W1, pH: 4.6–5.1 ± 0.02) and (W2 pH: 5.6–5.7 ± 0.02) was carried out during the rainy season at Ouagadougou–Burkina Faso, West Africa. The weather variation during the rainy season significantly affects the photo-disinfection processes (solar disinfection and photo-Fenton). The dilution of the water by rainwater highly affected the chemical composition of the wells' water used in this study; very low iron contents Compared to the ones recorded during the dry season were recorded in all water samples. Both photo-disinfection processes were used to treat 25 L of water in a compound parabolic collector (CPC). None of them have shown the total inactivation of both wild enteric bacteria strains (total coliforms/E. coli and Salmonella spp.) involved in the treatment. However, the total coliforms/E. coli strains were totally inactivated during the exposure under most of the photo-Fenton treatment. Also, the remaining strains, especially those of Salmonella spp. were achieved during the subsequent 24 h of dark storage under the action of the Fenton process. Under uniquely solar radiation, total inactivation was recorded only in the total coliforms/E. coli strains. The impact of the available irradiance on the efficiency of the photo-Fenton disinfection of natural water was highlighted during the exposure under high intermittent solar radiation. The impact of the HCO3− concentration of both wells' water on the evolution of the pH during the photo-disinfection was recorded. Drastic decrease was noticed after the initial fast increase in presence of low HCO3− concentration while a steady state was observed after the increase in presence of higher concentration. The redox activities of the nitrogen components of the water during both photo-disinfection processes have led to increased concentration of nitrite in all the cases and variations were noticed in that of nitrate and ammonia. - Graphical

  4. Heterogeneous photo-Fenton degradation of acid red B over Fe{sub 2}O{sub 3} supported on activated carbon fiber

    Energy Technology Data Exchange (ETDEWEB)

    Lan, Huachun [Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences,China (China); Wang, Aiming [Department of Municipal and Environmental Engineering, School of Civil Engineering, Beijing Jiaotong University,China (China); Liu, Ruiping, E-mail: liuruiping@rcees.ac.cn [Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences,China (China); Liu, Huijuan; Qu, Jiuhui [Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences,China (China)

    2015-03-21

    Highlights: • Fe{sub 2}O{sub 3} with small particle size was highly dispersed on activated carbon fiber. • Fe{sub 2}O{sub 3}/ACF exhibited higher photo-Fenton activity toward ARB degradation. • Fe{sub 2}O{sub 3}/ACF has an excellent long-term stability without obvious deactivation. - Abstract: Fe{sub 2}O{sub 3} supported on activated carbon fiber (Fe{sub 2}O{sub 3}/ACF) was prepared via an impregnation method and characterized by X-ray diffraction, scanning electron microscopy and BET analysis. The results indicated that Fe{sub 2}O{sub 3} with small particle size was highly dispersed on the surface of the ACF and the introduction of Fe{sub 2}O{sub 3} did not change the ACF pore structure. Fe{sub 2}O{sub 3}/ACF exhibited a higher Fenton efficiency for the degradation of acid red B (ARB), especially under simulated solar irradiation. Complete decoloration of the ARB solution and 43% removal of TOC could be achieved within 200 min under optimal conditions. It was verified that more ·OH radicals were generated in the photo-assisted Fenton process and involved as active species in ARB degradation. FTIR analysis indicated that the degradation of ARB was initiated through the cleavage of −N=N−, followed by hydroxylation and opening of phenyl rings to form aliphatic acids, and further oxidation of aliphatic acids would produce CO{sub 2} and H{sub 2}O. Moreover, Fe{sub 2}O{sub 3}/ACF maintained its activity after being reused 4 times and the release of iron from the catalyst was found to be insignificant during the Fenton and photo-Fenton processes, indicating that Fe{sub 2}O{sub 3}/ACF had good long-term stability.

  5. Nuclear Reactions

    OpenAIRE

    Bertulani, C. A.

    2009-01-01

    Nuclear reactions generate energy in nuclear reactors, in stars, and are responsible for the existence of all elements heavier than hydrogen in the universe. Nuclear reactions denote reactions between nuclei, and between nuclei and other fundamental particles, such as electrons and photons. A short description of the conservation laws and the definition of basic physical quantities is presented, followed by a more detailed account of specific cases: (a) formation and decay of compound nuclei;...

  6. Fenton法-聚合氯化铝预处理高浓度乳化液废水%Pretreatment of High Concentration of Emulsified Liquid Waste Water Using the Fenton Method and Poly Aluminium Chloride

    Institute of Scientific and Technical Information of China (English)

    王汉道; 冯振杰; 赵娜

    2014-01-01

    艺处理后处理水COD小于5000 mg·L-1,COD去除率达到87%以上,色度从浑浊的乳白色变成了清澈的无色,满足了后续生化处理对进水的水质要求。可为解决同类高浓度乳化液废水预处理提供技术参考。%Emulsion has received frequent usage in the proceeding of machine building and operation, for its role of lubrication, cooling, surface cleaning and corrosion prevention. The principal constituents are mineral oils, surface-active preparations, bacteria inhibitor and other organic additions. There is high concentration, over emulsification, complicated compositions and large fluctuation of emulsion wastewater during use. Willfully effluent would cause serious environment pollution. At present, there are lots of researches about the treatment of low concentration oily wastewater at home and abroad, such as emulsion breaking microbial catalyzing, and so on. However, all of these treatment methods have certain limitations, especially for the high concentration emulsion wastewater. Fenton method is an advanced oxide technique. Under the acidic conditions, H2O2 is catalytically decomposited and comes into lots of strong oxidizing •OH, which can degrade the organic matters in wastewater to purificate wastewater. This method has strong predominance to treat hazardous, toxic and hard to biological degradation of organic wastewater. As PAC is a very useful inorganic polymeric flocculant, there will be better effects when it is used in conjunction with other water treatment chemicals. Through Al(Ⅲ) salt hydrolysis product to neutralize electricity and absorb the colloidal solid or colloidal pollutants to clean wastewater. In the paper, Fenton method - PAC was adopted to pretreat high concentration emulsified wastewater of mechanical plant to meet the water requirements of the subsequent biological treatment. The experiment studies the initial pH of reaction, H2O2 dosage, dosage of ferrous sulfate and reaction time involved in Fenton method, and the

  7. Ethyl Chloride Wastewater Treatment by Stripping-Fenton Oxidizing-Sedimentation Treatment Process%吹脱-Fenton氧化-沉淀工艺处理乙基氯化物废水

    Institute of Scientific and Technical Information of China (English)

    曲毅; 柯爌琼; 吴翔; 王丽; 杜冬云

    2012-01-01

    乙基氯化物是重要的农药中间体,广泛用于生产高效低毒有机磷农药,在生产过程中产生大量高COD、高磷、高硫等污染物的有毒废水.文章针对该废水的水质,提出了一种新的预处理工艺:吹脱-Fenton氧化-沉淀反应.试验结果表明:当吹脱时间为20 min,pH为3.10,Fenton反应双氧水与亚铁离子摩尔比为4∶1,双氧水投加量为5 mL/L以及沉淀反应石灰投加量为14.5 g/L时,废水中的COD从228 g/L降低到56.60 g/L,硫离子浓度从88.94 g/L降低到12.26 g/L,总磷含量从10.37 g/L降低到0.98 g/L.%Ethyl chloride as an important intermediate product of pesticide is widely used to produce higher effective and lower toxic organophosphorus pesticide. Toxic wastewater generated in the production process contains high levels of COD, total phosphorus and sulfur ion.According to nature of the wastewater, a new pretreatment process was proposed, including stripping, Fenton oxidation and calcium precipitation.Results showed that COD concentration reduced from 228 g/L to 56.60 g/L, sulfur ion concentration reduced from 88.94 g/L to 12.26 g/L and total phosphorus concentration reduced from 10.37 g/L to 0.98 g/L after pretreatment in condition that stripping time was 20 min, pH 3.10, Fenton reactor H2O2/FeSO,, mole rate was 4:1, H2O2 dosage was 5 mL/L and precipitation reaction lime dosage was 14.5 g/L.

  8. Study on coagulation-Fenton reagent method in advanced treatment of pharmaceutical wastewater%混凝-Fenton法在制药废水生化处理后出水深度处理中的研究

    Institute of Scientific and Technical Information of China (English)

    王晴

    2011-01-01

    采用混凝-Fenton试剂法对制药废水生化处理后的出水进行深度处理,通过正交试验研究了FeSO4·7H2O试剂、H2O2用量和反应时间等因素对COD去除率的影响,在最佳处理条件下,脱色效果较好,为制药废水生化处理后出水的深度处理提供了一种可行的方法.%Coagulation-Fenton process was chosen for the advanced treatment of pharmaceutical wastewater. Orthogonal experiment was used to study the influence of the amount of FeSO4 · 7 H2O and H2O2 and the reaction time on the COD removal rate. By analyzing the data of orthogonal experiment, the best treatment conditions is determined, ard the removal rate of chromaticity is relatively high. A feasible method for advanced treatment of pharmaceutical wastewater is provided by this study.

  9. UV/Fenton法降解四环素废水的试验研究%Study on Degradation of Tetracycline Wastewater by UV/Fenton Process

    Institute of Scientific and Technical Information of China (English)

    汪艳宁; 卢广守

    2011-01-01

    The influences of initial concentrations of the FeSO4, H2O2 and solution pH values on the degradation of tetracycline wastewater by UV/Fenton process were analyzed. Experimental results indicate that when the initial concentration of tetracycline was 25 mg/L, the optimum operational conditions of the processes were as follows: the initial concentration 0.05 mmol/L FeSO4, 10 mmol/L H2O2, pH2.5. After 60 minutes' reaction, the tetracycline removal rate was 93.14%. In addition, comparative tests on varous lighting conditions (natural daylight, sunlight and UV-light) were conducted. The results show that the tetracycline removal rate was highest under UV irradiation, a little lower under sufllight, lowest under natural daylight.%分析了FeSO4和H2O2的初始浓度及溶液pH值对UV/Fenton法降解四环素废水的影响.结果表明四环素的初始浓度为25mg/L时,降解四环素的最佳工况:FeS04的初始浓度为0.05mmol/L,H2O2的初始浓度为10mmol/L,pH值为2.5,在反应时间为60min时,对四环素的去除率可达93.14%.另外,对自然光、太阳光、紫外光三种不同光照条件进行了对比试验,得出紫外光辐照下的四环素去除率最高,太阳光次之,自然光最小.

  10. Nanocasted synthesis of magnetic mesoporous iron cerium bimetal oxides (MMIC) as an efficient heterogeneous Fenton-like catalyst for oxidation of arsenite

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Zhipan [State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092 (China); Zhang, Yalei, E-mail: zhangyalei@tongji.edu.cn [State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092 (China); Dai, Chaomeng [College of Civil Engineering, Tongji University, Shanghai 200092 (China); Sun, Zhen [State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092 (China)

    2015-04-28

    Highlights: • MMIC with large surface area and pore volume was synthesized via the hard template. • MMIC could be easily separated from aqueous solution with an external magnetic field. • MMIC presented excellent catalytic activity for the oxidation of As(III). • As(III) was mainly oxidized by surface-bound ·OH{sub ads} and free ·OH{sub free} radicals. • MMIC played a dual function role for the arsenic removal in aqueous solution. - Abstract: Magnetic mesoporous iron cerium bimetal oxides (MMIC) with large surface area and pore volume was synthesized via the hard template approach. This obtained MMIC was easily separated from aqueous solution with an external magnetic field and was proposed as a heterogeneous Fenton-like catalyst for oxidation of As(III). The MMIC presented excellent catalytic activity for the oxidation of As(III), achieving almost complete oxidation of 1000 ppb As(III) after 60 min and complete removal of arsenic species after 180 min with reaction conditions of 0.4 g/L catalyst, pH of 3.0 and 0.4 mM H{sub 2}O{sub 2}. Kinetics analysis showed that arsenic removal followed the pseudo-first order, and the pseudo-first-order rate constants increased from 0.0014 min{sup −1} to 0.0548 min{sup −1} as the H{sub 2}O{sub 2} concentration increased from 0.04 mM to 0.4 mM. On the basis of the effects of XPS analysis and reactive oxidizing species, As(III) in aqueous solution was mainly oxidized by ·OH radicals, including the surface-bound ·OH{sub ads} generated on the MMIC surface which were involved in ≡Fe{sup 2+} and ≡Ce{sup 3+}, and free ·OH{sub free} generation by soluble iron ions which were released from the MMIC into the bulk solution, and the generated As(V) was finally removed by MMIC through adsorption.

  11. Preparation of zeolite nanorods by corona discharge plasma for degradation of phenazopyridine by heterogeneous sono-Fenton-like process.

    Science.gov (United States)

    Khataee, Alireza; Rad, Tannaz Sadeghi; Vahid, Behrouz; Khorram, Sirous

    2016-11-01

    The plasma-modified clinoptilolite (PMC) nanorods were prepared from natural clinoptilolite (NC) utilizing environmentally-friendly corona discharge plasma. The PMC and NC were characterized by XRD, FT-IR, SEM, EDX, XPS and BET, which confirmed the nanocatalyst formation. The catalytic performance of the PMC in the heterogeneous sono-Fenton-like process was greater than the NC for treatment of phenazopyridine (PhP). The desired amounts were obtained for experimental parameters including initial pH (5), PMC dosage (2g/L), K2S2O8 concentration (2mmol/L), ultrasonic power (300W) and PhP concentration (10mg/L). Reactive oxygen species scavengers decreased the removal efficiency of the PhP. The treatment process followed pseudo-first order kinetic and seven degradation intermediates were identified by the GC-MS technique. PMID:27245954

  12. Heterogeneous photo-Fenton decolorization of methylene blue over LiFe(WO4)2 catalyst

    International Nuclear Information System (INIS)

    Heterogeneous photo-Fenton process using LiFe(WO4)2 as catalyst was studied to degrade Methylene blue (MB) dye in aqueous solution. The results indicated that LiFe(WO4)2 could effectively catalyze the decolorization of MB in the presence of UV light and H2O2. The effects of different parameters such as amounts of catalyst, H2O2 concentration, initial pH of the dye solution, initial dye concentration and UV light intensity on the decolorization efficiency of the process were investigated. It was found that LiFe(WO4)2 possessed a wide applicable pH range. X-ray photoelectron spectroscopy (XPS) was applied to investigate the transformation between Fe(III) and Fe(II). It was also observed that catalytic behavior could be reproduced in consecutive experiments without a considerable drop in the process efficiency.

  13. photo-Fenton试剂法降解硝基苯废水%Degrading nitrobenzene from water with photo-Fenton

    Institute of Scientific and Technical Information of China (English)

    黄宁; 王小雨

    2009-01-01

    应用photo-Fenton过氧化过程研究对硝基苯水溶液的降解.测定反应物质量质量浓度、温度和pH对硝基苯降解的影响.使photo-Fenton法更加有效的降解水溶液中的硝基苯.在pH等于3、初始质量质量浓度H2O2为200 mg/L、Fe2+为30 mg/ L条件下仅在30min内应用photo-Fenton 法可将硝基苯降解50 %左右(硝基苯初始质量浓度为200 mg/ L)完全降解.

  14. Fenton氧化法处理填埋渗滤液%Treatment of Landfill Leachate by Fenton Oxidation Process

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Central composite design (CCD), the most popular design of response surface methodology (RSM),was employed to investigate the effect of total organic carbon(TOC) ratio of high molecular weight organic matter (HMW) to low molecular weight organic matter (LMW), the LMW strength and molar ratio of hydrogen peroxide to ferrous ion on landfill leachate treatment by Fenton process. Based on the experimental data, a response surface quadratic model in terms of actual factors was obtained through analysis of variance (ANOVA). The model showed that TOC removal increased with the increase of HMW to LMW ratio and the decrease of LMW strength. There existed an optimal hydrogen peroxide to ferrous ion molar ratio for TOC removal.

  15. Heterogeneous advanced photo-fenton oxidation of phenolic aqueous solutions over iron-containing SBA-15 catalyst

    Directory of Open Access Journals (Sweden)

    Bailiche Z.

    2013-09-01

    Full Text Available Iron-containing SBA15 catalysts have been prepared following different synthesisroutes, direct synthesis by adjusting pH at 3 and 6 and with post synthesis procedure. Activity and stability of these materials were assessed on the photo-Fenton degradation of phenolic aqueous solutions by H2O2 using near UV irradiation (254 nm at room temperature and initial neutral pH. Their catalytic performance was mentioned in terms of phenol and total organic carbon (TOC conversions. Several complementary techniques, including XRD, Nitrogen sorption isotherms, UV visible, were used to evaluate the final structural and textural properties of calcined Fe-SBA15 materials. These materials show a high activity and stability of iron species.

  16. Automatic dosage of hydrogen peroxide in solar photo-Fenton plants: Development of a control strategy for efficiency enhancement

    International Nuclear Information System (INIS)

    Highlights: ► Dissolved oxygen monitoring is used for automatic dosage of H2O2 in photo-Fenton. ► PI with anti-windup minimises H2O2 consumption. ► The H2O2 consumption was reduced up to 50% with respect to manual addition strategies. ► Appropriate H2O2 dosage is achieved by PI with anti-windup under disturbances. - Abstract: The solar photo-Fenton process is widely used for the elimination of pollutants in aqueous effluent and, as such, is amply cited in the literature. In this process, hydrogen peroxide represents the highest operational cost. Up until now, manual dosing of H2O2 has led to low process performance. Consequently, there is a need to automate the hydrogen peroxide dosage for use in industrial applications. As it has been demonstrated that a relationship exists between dissolved oxygen (DO) concentration and hydrogen peroxide consumption, DO can be used as a variable in optimising the hydrogen peroxide dosage. For this purpose, a model was experimentally obtained linking the dynamic behaviour of DO to hydrogen peroxide consumption. Following this, a control system was developed based on this model. This control system – a proportional and integral controller (PI) with an anti-windup mechanism – has been tested experimentally. The assays were carried out in a pilot plant under sunlight conditions and with paracetamol used as the model pollutant. In comparison with non-assisted addition methods (a sole initial or continuous addition), a decrease of 50% in hydrogen peroxide consumption was achieved when the automatic controller was used, driving an economic saving and an improvement in process efficiency.

  17. Tantalum (oxy)nitrides: Preparation, characterisation and enhancement of photo-Fenton-like degradation of atrazine under visible light

    International Nuclear Information System (INIS)

    Highlights: → The photocatalytic activity of TaON for Fe3+ reduction is higher than that of Ta3N5. → Atrazine degradation was accelerated significantly by tantalum (oxy)nitrides sample. → The regenerated catalyst displays considerably stable performance for atrazine degradation. - Abstract: Tantalum (oxy)nitrides were prepared by the nitridation of Ta2O5 and were added to a photo-Fenton-like system to enhance Fe3+ reduction and atrazine degradation under visible light. The samples were characterized by XRD, XPS, DRS and BET analyses. XPS analysis showed that the nitrogen content of the tantalum (oxy)nitride samples increased noticeably with the nitridation temperature and nitridation time but slightly with the flow rate of NH3. XRD results showed Ta2O5 was first converted to TaON and then to Ta3N5 when the nitridation temperature increased. DRS analysis showed that the sample obtained at 800 oC displayed the strongest absorption of visible light. However, the ability of the tantalum (oxy)nitrides to reduce Fe3+ did not increase continuously with the nitrogen content. Sample 7 (700 oC, QNH3=0.3L/min, 6 h) showed the highest level of photocatalytic activity for Fe3+ reduction. This is because the photocatalytic activity of TaON for Fe3+ reduction is higher than that of Ta3N5. And a slight synergetic effect was observed between TaON and Ta3N5. With the addition of sample 7, H2O2 decomposition and atrazine degradation were significantly accelerated in a photo-Fenton-like system under visible light. The regenerated tantalum (oxy)nitrides catalyst displayed considerably stable performance for atrazine degradation.

  18. Tantalum (oxy)nitrides nanotube arrays for the degradation of atrazine in vis-Fenton-like process

    International Nuclear Information System (INIS)

    Highlights: ► Tantala nanotubes on a Ta foil were formed by anodization in a NH4F-containing electrolyte. ► Tantalum (oxy)nitrides nanotubes were active for Fe3+ reduction under visible light. ► Atrazine degradation by ·OH was accelerated with tantalum (oxy)nitrides nanotubes. ► Tantalum (oxy)nitrides nanotubes display stable performance for atrazine degradation. - Abstract: In order to overcome the limitation of the application of nanoparticles, tantalum (oxy)nitrides nanotube arrays on a Ta foil were synthesized and introduced in vis (visible light)-Fenton-like system to enhance the degradation of atrazine. At first, the anodization of tantalum foil in a mild electrolyte solution containing ethylene glycol and water (v:v = 2:1) plus 0.5 wt.% NH4F produced tantala nanotubes with an average diameter of 30 nm and a length of approximately 1 μm. Then the nitridation of tantala nanotube arrays resulted in the replacement of N atoms to O atoms to form tantalum (oxy)nitrides (TaON and Ta3N5), as testified by XRD and XPS analyses. The synthesized tantalum (oxy)nitrides nanotubes absorb well in the visible region up to 600 nm. Under visible light, tantalum (oxy)nitrides nanotube arrays were catalytically active for Fe3+ reduction. With tantalum (oxy)nitrides nanotube arrays, the degradation of atrazine and the formation of the intermediates in vis/Fe3+/H2O2 system were significantly accelerated. This was explained by the higher concentration of Fe2+ and thus the faster decomposition of H2O2 with tantalum (oxy)nitrides nanotubes. In addition, tantalum (oxy)nitrides nanotubes exhibited stable performance during atrazine degradation for three runs. The good performance and stability of the tantalum (oxy)nitrides nanotubes film with the convenient separation, suggest that this film is a promising catalyst for vis-Fenton-like degradation.

  19. Evaluation of three reagent dosing strategies in a photo-Fenton process for the decolorization of azo dye mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Prato-Garcia, D. [Laboratory for Research on Advanced Processes for Water Treatment, Instituto de Ingenieria, Unidad Academica Juriquilla, Universidad Nacional Autonoma de Mexico, Blvd. Juriquilla 3001, Queretaro 76230 (Mexico); Buitron, German, E-mail: gbuitronm@iingen.unam.mx [Laboratory for Research on Advanced Processes for Water Treatment, Instituto de Ingenieria, Unidad Academica Juriquilla, Universidad Nacional Autonoma de Mexico, Blvd. Juriquilla 3001, Queretaro 76230 (Mexico)

    2012-05-30

    Highlights: Black-Right-Pointing-Pointer Dosing strategies for a photo-Fenton process were evaluated. Black-Right-Pointing-Pointer The dosing strategy had no effect of on the decolorization. Black-Right-Pointing-Pointer The type of strategy influenced SUVA index, toxicity reduction and biodegradability. Black-Right-Pointing-Pointer A continuous reagents supply was found to be the most adequate strategy. Black-Right-Pointing-Pointer Decolorization as well as a less toxic and biodegradable effluent was produced. - Abstract: Three reagent dosing strategies used in the solar photo-assisted decolorization of a mixture of sulfonated dyes consisting of acid blue 113, acid orange 7 and acid red 151 were evaluated. Results demonstrated that the dosing strategy influenced both reagent consumption and the biodegradability and toxicity of the effluent. In one strategy (E{sub 1}), the Fenton's reactants were dosed in a punctual mode, while in the other two strategies (E{sub 2} an E{sub 3}), the reactants were dosed continuously. In the E{sub 2} strategy the reactants were dosed by varying the duration of the injection time. In the E{sub 3} strategy, the reactants were dosed during 60 min at a constant rate, but with different concentrations. All cases showed that feeding the reactor between 40% and 60% of the maximal dose was sufficient to decolorize more than 90% of the mixture of azo dyes. The E{sub 1} strategy was less effective for aromatic content reduction. Conversely, the continuous addition of the reagents (E{sub 2} and E{sub 3} strategies) improved the aromatic content removal. E{sub 3} strategy was substantially more appropriate than E{sub 1} strategy due to improved the effluent quality in two key areas: toxicity and biodegradability.

  20. Automatic dosage of hydrogen peroxide in solar photo-Fenton plants: Development of a control strategy for efficiency enhancement

    Energy Technology Data Exchange (ETDEWEB)

    Ortega-Gomez, E. [Department of Chemical Engineering, University of Almeria, 04120 Almeria (Spain); CIESOL, Joint Centre of the University of Almeria-CIEMAT, 04120 Almeria (Spain); Moreno Ubeda, J.C. [Department of Language and Computation, University of Almeria, 04120 Almeria (Spain); Alvarez Hervas, J.D. [Department of Language and Computation, University of Almeria, 04120 Almeria (Spain); Department of Language and Computation, University of Sevilla, 41092 Sevilla (Spain); Casas Lopez, J.L.; Santos-Juanes Jorda, L. [Department of Chemical Engineering, University of Almeria, 04120 Almeria (Spain); CIESOL, Joint Centre of the University of Almeria-CIEMAT, 04120 Almeria (Spain); Sanchez Perez, J.A., E-mail: jsanchez@ual.es [Department of Chemical Engineering, University of Almeria, 04120 Almeria (Spain); CIESOL, Joint Centre of the University of Almeria-CIEMAT, 04120 Almeria (Spain)

    2012-10-30

    Highlights: Black-Right-Pointing-Pointer Dissolved oxygen monitoring is used for automatic dosage of H{sub 2}O{sub 2} in photo-Fenton. Black-Right-Pointing-Pointer PI with anti-windup minimises H{sub 2}O{sub 2} consumption. Black-Right-Pointing-Pointer The H{sub 2}O{sub 2} consumption was reduced up to 50% with respect to manual addition strategies. Black-Right-Pointing-Pointer Appropriate H{sub 2}O{sub 2} dosage is achieved by PI with anti-windup under disturbances. - Abstract: The solar photo-Fenton process is widely used for the elimination of pollutants in aqueous effluent and, as such, is amply cited in the literature. In this process, hydrogen peroxide represents the highest operational cost. Up until now, manual dosing of H{sub 2}O{sub 2} has led to low process performance. Consequently, there is a need to automate the hydrogen peroxide dosage for use in industrial applications. As it has been demonstrated that a relationship exists between dissolved oxygen (DO) concentration and hydrogen peroxide consumption, DO can be used as a variable in optimising the hydrogen peroxide dosage. For this purpose, a model was experimentally obtained linking the dynamic behaviour of DO to hydrogen peroxide consumption. Following this, a control system was developed based on this model. This control system - a proportional and integral controller (PI) with an anti-windup mechanism - has been tested experimentally. The assays were carried out in a pilot plant under sunlight conditions and with paracetamol used as the model pollutant. In comparison with non-assisted addition methods (a sole initial or continuous addition), a decrease of 50% in hydrogen peroxide consumption was achieved when the automatic controller was used, driving an economic saving and an improvement in process efficiency.

  1. Performance evaluation of modified Fenton process using Nano scale zero-valent iron in nitrate reduction from aqueous solution

    Directory of Open Access Journals (Sweden)

    Behrooz karimi

    2013-05-01

    Full Text Available Backgrounds and Objectives: Nowadays, global concerns about nitrate in groundwater and its adverse impact on health have increased. This study aims to evaluate the efficiency of nitrate reduction from aqueous solution through modified Fenton process using Nano scale zero-valent iron. Material and Methods: This research was an experimental study and performed at laboratory scale. Nitrate reduction was conducted by advanced oxidation process of Fe°/FeІІ/FeШ/H2O2 at pH 2-10, contact time 10-90 min, nitrate concentrations of 50-300 mg/L, and the molar ratio of [H2O2]/[Fe] 0.5-5. The effect of adding H2O2, molar ratio of reagents, contact time, and pH on nitrate removal was examined and optimal conditions for each of these parameters were determined. Spectrophotometer Dr/5000 was used to measure nitrate in the effluent. Results: We found that the optimal parameters in our studywere pH 3, the molar ratio [H2O2]/[Fe°] of 0.5, and the contact time 15 min. By applying these conditions, nitrate removal efficiency at the retention time 15 min, initial nitrate concentration of 100 mg/L, iron concentration of 10 mg/L, and pH 4 for FeШ، FeІІ، Fe°، FeІІ/Fe°/H2O2 and FeШ/Fe°/H2O2 was 10.5, 27.6, 36.5, 62.3, and 74% respectively. Conclusion: According to the experimental results, it was determined that modified Fenton process using zero iron nano-particles can reduce nitrate under optimal conditions and this method can be used for the removal of similar compounds.

  2. Adsorption-regeneration by heterogeneous Fenton process using modified carbon and clay materials for removal of indigo blue.

    Science.gov (United States)

    Almazán-Sánchez, Perla Tatiana; Solache-Ríos, Marcos J; Linares-Hernández, Ivonne; Martínez-Miranda, Verónica

    2016-07-01

    Indigo blue dye is mainly used in dyeing of denim clothes and its presence in water bodies could have adverse effects on the aquatic system; for this reason, the objective of this study was to promote the removal of indigo blue dye from aqueous solutions by iron and copper electrochemically modified clay and activated carbon and the saturated materials were regenerated by a Fenton-like process. Montmorillonite clay was modified at pH 2 and 7; activated carbon at pH 2 and pH of the system. The elemental X-ray dispersive spectroscopy analysis showed that the optimum pH for modification of montmorillonite with iron and copper was 7 and for activated carbon was 2. The dye used in this work was characterized by infrared. Unmodified and modified clay samples showed the highest removal efficiencies of the dye (90-100%) in the pH interval from 2 to 10 whereas the removal efficiencies decrease as pH increases for samples modified at pH 2. Unmodified clay and copper-modified activated carbon at pH 2 were the most efficient activated materials for the removal of the dye. The adsorption kinetics data of all materials were best adjusted to the pseudo-second-order model, indicating a chemisorption mechanism and the adsorption isotherms data showed that the materials have a heterogeneous surface. The iron-modified clay could be regenerated by a photo-Fenton-like process through four adsorption-regeneration cycles, with 90% removal efficiency. PMID:26878687

  3. Reaction mechanism of dicofol removal by cellulase.

    Science.gov (United States)

    Wang, Ziyuan; Yang, Ting; Zhai, Zihan; Zhang, Boya; Zhang, Jianbo

    2015-10-01

    It remains unclear whether dicofol should be defined as a persistent organic pollutant. Its environmental persistence has gained attention. This study focused on its degradation by cellulase. Cellulase was separated using a gel chromatogram, and its degradation activity towards dicofol involved its endoglucanase activity. By analyzing the kinetic parameters of cellulase reacting with mixed substrates, it was shown that cellulase reacted on dicofol and carboxyl methyl cellulose through two different active centers. Thus, the degradation of dicofol was shown to be an oxidative process by cellulase. Next, by comparing the impacts of tert-butyl alcohol (a typical OH free-radical inhibitor) on the removal efficiencies of dicofol under both cellulase and Fenton reagent systems, it was shown that the removal of dicofol was initiated by OH free radicals produced by cellulase. Finally, 4,4'-dichloro-dibenzophenone and chloride were detected using gas chromatography mass spectrometry and ion chromatography analysis, which supported our hypothesis. The reaction mechanism was analyzed and involved an attack by OH free radicals at the orthocarbon of dicofol, resulting in the degradation product 4,4'-dichloro-dibenzophenone. PMID:26456602

  4. Combined processes of two-stage Fenton-biological anaerobic filter-biological aerated filter for advanced treatment of landfill leachate.

    Science.gov (United States)

    Wang, Xiaojun; Han, Jijun; Chen, Zhiwei; Jian, Lei; Gu, Xiaoyang; Lin, Che-Jen

    2012-12-01

    There are numerous non-biodegradable organic materials in the mature landfill leachate. To meet the new discharge standard of China, additional advanced treatment is needed for the effluent from the biological treatment processes of leachate. In this study, a combined process including two stages of "Fenton-biological anaerobic filter (BANF)-biological aerated filter (BAF)" was evaluated to address the advanced treatment need. The Fenton oxidation was applied to reduce chemical oxygen demand (COD) and enhance biodegradability of refractory organics, and the BANF-BAF process was then applied to remove the total nitrogen (TN). The treatment achieved effluent concentrations of CODcost of these processes was about 36.1CHY/t (5.70USD/t). PMID:22841597

  5. Treatment of Phenolic Wastewater by Combining UV-Fenton Oxidation with Biological Oxidation%UV-Fenton氧化-生化法联合处理含酚废水

    Institute of Scientific and Technical Information of China (English)

    刘琼玉; 刘君侠; 刘延湘

    2011-01-01

    Phenolic wastewater was treated by combined process of UV-Fenton oxidation-biological oxidation. Treatment efficiency of phenolic wastewater by single UV-Fenton oxidation,single biological oxidation and combined process were compared. Results indicated that effective degradation of coal-gas phenolic wastewater was observed by UV-Fenton process,but complete degradation of phenolic wastewater need to consume large numbers of H2O2 with high cost,which is uneconomical. Direct biological oxidation cannot efficient treat coal-gas phenolic wastewater due to low ratio of BODs/COD.UV-Fenton preoxidation is effective at enhancing biodegradability of coal-gas phenolic wastewater,and the biodegradability of wastewater enhanced obviously with increasing dosage of H2O2 in UV-Fenton preoxidation. When H2O2 was added only 21.6% of stoichiometric calculated quantities,COD would reduce from 1,306 mg/L to 121 mg/L and phenol reduced from 193.5 mg/L to 0.43 mg/L,both COD and phenol of coal-gas phenolic wastewater can satisfy national control standard by combined process of UV-Fenton oxidation-biological oxidation. Experimental results showed that 75% H2O2 were saved by combined process of UV-Fenton oxidation-biological oxidation, comparing with single UV-Fenton process.%采用UV-Fenton氧化-生化法联合处理煤气含酚废水,比较了单独UV-Fenton氧化法、单独生化法和UV-Fenton氧化-生化法联合工艺对煤气含酚废水的处理效果.结果表明,UV-Fenton氧化体系可有效降解含酚废水,但废水完全降解所需的H2O2用量大,处理成本高.煤气含酚废水的BOD5/COD比值较低,直接采用生化处理的效果不理想,通过UV-Fenton氧化预处理可明显提高煤气含酚废水的生物降解性,随着H2O2投加量的增加,废水的BOD5/COD比值逐渐增大,生物降解性明显增强.当UV/Fenton氧化过程H2O2用量为21.6%理论投加量时,采用UV-Fenton氧化-生化法联合工艺可使煤气含酚废水的COD由1306mg

  6. Fenton Coagulation/Oxidation Using Fe2+ and Fe3+ Íons and Peracetic Acid for the Treatment of Wastewater

    Directory of Open Access Journals (Sweden)

    Grasiele Soares Cavallini

    2015-09-01

    Full Text Available The Fenton coagulation/oxidation process is divided into two steps: coagulation, in alkaline pH and oxidation, in acid pH. This configuration provides a reduction in oxidant concentration, due to the pretreatment conducted in the coagulation step. This study proposes the substitution of hydrogen peroxide (HP by peracetic acid (PAA in a Fenton coagulation process to treat sanitary sewage and provide its disinfection. The new combination is proposed in a single step and presented good results in removing turbidity (98.5%, apparent color (95.4%, phosphorus (100% and COD (58.2% even at the effluent natural pH, besides demonstrating higher reduction in E. coli when compared with the process that employs hydrogen peroxide. The formation of Fe3+ ions was shown to be responsible for the removal of the particulate material. DOI: http://dx.doi.org/10.17807/orbital.v7i3.626 

  7. Solar photo-Fenton process on the abatement of antibiotics at a pilot scale: Degradation kinetics, ecotoxicity and phytotoxicity assessment and removal of antibiotic resistant enterococci.

    Science.gov (United States)

    Michael, I; Hapeshi, E; Michael, C; Varela, A R; Kyriakou, S; Manaia, C M; Fatta-Kassinos, D

    2012-11-01

    This work investigated the application of a solar driven advanced oxidation process (solar photo-Fenton), for the degradation of antibiotics at low concentration level (μg L(-1)) in secondary treated domestic effluents at a pilot-scale. The examined antibiotics were ofloxacin (OFX) and trimethoprim (TMP). A compound parabolic collector (CPC) pilot plant was used for the photocatalytic experiments. The process was mainly evaluated by a fast and reliable analytical method based on a UPLC-MS/MS system. Solar photo-Fenton process using low iron and hydrogen peroxide doses ([Fe(2+)](0) = 5 mg L(-1); [H(2)O(2)](0) = 75 mg L(-1)) was proved to be an efficient method for the elimination of these compounds with relatively high degradation rates. The photocatalytic degradation of OFX and TMP with the solar photo-Fenton process followed apparent first-order kinetics. A modification of the first-order kinetic expression was proposed and has been successfully used to explain the degradation kinetics of the compounds during the solar photo-Fenton treatment. The results demonstrated the capacity of the applied advanced process to reduce the initial wastewater toxicity against the examined plant species (Sorghum saccharatum, Lepidium sativum, Sinapis alba) and the water flea Daphnia magna. The phytotoxicity of the treated samples, expressed as root growth inhibition, was higher compared to that observed on the inhibition of seed germination. Enterococci, including those resistant to OFX and TMP, were completely eliminated at the end of the treatment. The total cost of the full scale unit for the treatment of 150 m(3) day(-1) of secondary wastewater effluent was found to be 0.85 € m(-3). PMID:22901406

  8. Development of a Photo-Fenton Catalyst Supported on Modified Polymer Films: Preparation, Characterization and Implication for Water Decontamination by Solar Photocatalysis

    OpenAIRE

    Mazille, Félicien

    2010-01-01

    The work presented in this thesis is a part of the European project INNOWATECH. The global objective of this project was to provide effective technological solutions for the treatment of industrial wastewater, to propose new concepts in wastewater treatment with potential benefits for the protection of the environment. In particular photo-assisted Fenton oxidation was investigated. It is a promising technology to decontaminate industrial wastewater ...

  9. Renovation and Reuse of Reactive Dyeing Effluent by a Novel Heterogeneous Fenton System Based on Metal Modified PTFE Fibrous Catalyst/H2O2

    OpenAIRE

    Bing Li; Yongchun Dong; Zhizhong Ding; Yiming Xu; Chi Zou

    2013-01-01

    Cu-Fe bimetallic grafted polytetrafluoroethylene (PTFE) fiber complexes were prepared and optimized as the novel heterogeneous Fenton catalysts for the degradation of reactive dyes under UV irradiation. Cotton fabrics were dyed with three reactive dyes, namely, Reactive Red 195, Reactive Yellow 145, and Reactive Blue 222, in tap fresh water using exhaustion process. The spent dyeing effluents were then collected and degraded with the optimized Cu-Fe bimetallic grafted PTFE fiber complex/H2O2 ...

  10. Heterogeneous fenton-like degradation of an azo dye reactive brilliant orange by the combination of activated carbon-FeOOH catalyst and H 2O2

    DEFF Research Database (Denmark)

    Wu, Jinhua; Lin, Guanghui; Li, Ping;

    2013-01-01

    The decoloration of an azo dye reactive brilliant orange (X-GN) by a heterogeneous Fenton system using activated carbon-FeOOH catalyst (AC-FeOOH) and H2O2 was studied. Under typical conditions (pH 7.0, H2O2 10 mmol/L, AC-FeOOH 1.0g/L and 30°C), 98% decoloration rate of X-GN was achieved in 240 mm...

  11. Removal of pharmaceuticals from MWTP effluent by nanofiltration and solar photo-Fenton using two different iron complexes at neutral pH.

    Science.gov (United States)

    Miralles-Cuevas, S; Oller, I; Sánchez Pérez, J A; Malato, S

    2014-11-01

    In recent years, membrane technologies (nanofiltration (NF)/reverse osmosis (RO)) have received much attention for micropollutant separation from Municipal Wastewater Treatment Plant (MWTP) effluents. Practically all micropollutants are retained in the concentrate stream, which must be treated. Advanced Oxidation Processes (AOPs) have been demonstrated to be a good option for the removal of microcontaminants from water systems. However, these processes are expensive, and therefore, are usually combined with other techniques (such as membrane systems) in an attempt at cost reduction. One of the main costs in solar photo-Fenton comes from reagent consumption, mainly hydrogen peroxide and chemicals for pH adjustment. Thus, in this study, solar photo-Fenton was used to treat a real MWTP effluent with low initial iron (less than 0.2 mM) and hydrogen peroxide (less than 2 mM) concentrations. In order to work at neutral pH, iron complexing agents (EDDS and citrate) were used in the two cases studied: direct treatment of the MWTP effluent and treatment of the concentrate stream generated by NF. The degradation of five pharmaceuticals (carbamazepine, flumequine, ibuprofen, ofloxacin and sulfamethoxazole) spiked in the effluent at low initial concentrations (μg L(-1)) was monitored as the main variable in the pilot-plant-scale photo-Fenton experiments. In both effluents, pharmaceuticals were efficiently removed (>90%), requiring low accumulated solar energy (2 kJUV L(-1), key parameter in scaling up the CPC photoreactor) and low iron and hydrogen peroxide concentrations (reagent costs, 0.1 and 1.5 mM, respectively). NF provided a clean effluent, and the concentrate was positively treated by solar photo-Fenton with no significant differences between the direct MWTP effluent and NF concentrate treatments. PMID:25025178

  12. Adaptation of a load-inject valve for a flow injection chemiluminescence system enabling dual-reagent injection enhances understanding of environmental Fenton chemistry

    International Nuclear Information System (INIS)

    Graphical abstract: -- Highlights: •Measurement of multiple components of Fenton chemistry; Fe(II) and H2O2. •Rapid, quasi-simultaneous analysis enables calculation of environmental kinetics. •Low, nano to pico-molar detection limits with dual analyte analysis. •Able to measure complex matrix samples – organically enriched seawater. •Low cost system with appreciable sensitivity compared to single analyte analysis. -- Abstract: Environmental Fenton chemistry has been poorly constrained within the marine environment at a multi-component level. A simple, unique, reconfiguration of a flow-injection analytical system combined with luminol chemiluminescence allows quasi-simultaneously the measurement, using a single load-inject valve and a single photon multiplier tube, of reduced iron, Fe(II), and hydrogen peroxide. The system enables rapid, every 22 s, measurements with good accuracy at environmentally relevant concentrations, less than 5% relative standard deviations on both a 5 nM Fe(II) standard and a 60 nM hydrogen peroxide standard. Limits of detection were as low as 40 pM Fe(II) and 100 pM hydrogen peroxide. The system showed excellent capability by measuring from within an organic rich seawater the photochemically induced production of Fe(II) and hydrogen peroxide and their subsequent cycling and Fenton like interactions

  13. Targeting key metabolic points for an enhanced phytoremediation of wastewaters pre-treated by the photo-Fenton process using Solanum nigrum L.

    Science.gov (United States)

    Teixeira, Jorge; Ferraz, Pedro; Gouveia, Carlota; Azevedo, Frederico; Neves, Simão; Fidalgo, Fernanda; Silva, Adrián M T

    2015-10-01

    Several physiological, biochemical and molecular biology responses were analysed in Solanum nigrum L. plants exposed for 28 days to an effluent that resulted from the photo-Fenton treatment of a highly concentrated pesticide and systemic fungicide aqueous solution, containing metalaxyl as active compound (150mgL(-1)), in order to pinpoint metabolic steps for a future increase of these plants' capacity to deal with the chemical process by-products. Although plants suffered oxidative stress, as indicated by increased membrane damage and a negative effect on plant biomass, they absorbed the excess iron and acted on the resulting by-products present in the effluent after the photo-Fenton process. Nitrogen assimilation and metallothionein gene expression were down regulated, while glutathione biosynthesis increased. These results suggest an enhanced nitrogen assimilation and/or metallothionein accumulation as relevant key points for further plant improvement in order to increase the efficiency of this innovative strategy that considers integration of the photo-Fenton process (as chemical primary treatment) with S. nigrum L. plants (as biological remediation post-treatment) for heavily polluted wastewaters. PMID:26057079

  14. Piezonuclear Reactions

    CERN Document Server

    Cardone, Fabio; Petrucci, Andrea

    2010-01-01

    In this paper, we deal with the subject of piezonuclear reactions, namely nuclear reactions (of new type) triggered by pressure waves. We discuss the experimental evidences obtained in the last two decades, which can be summarized essentially as follows: experiments in cavitation of liquids, where transmutation of elements, creation of elements and emission of neutrons have been observed; emission of neutrons in brittle failure of solids subjected to mechanical pressure; alteration of the lifetime of un unstable element (thorium) subjected to cavitation. A theoretical model to explain these facts is proposed. Future perspectives of these experimental and theoretical investigations are also underlined.

  15. Reaction mechanisms

    International Nuclear Information System (INIS)

    The 1988 progress report of the Reaction Mechanisms laboratory (Polytechnic School, France), is presented. The research topics are: the valence bond methods, the radical chemistry, the modelling of the transition states by applying geometric constraints, the long range interactions (ion - molecule) in gaseous phase, the reaction sites in gaseous phase and the mass spectroscopy applications. The points of convergence between the investigations of the mass spectroscopy and the theoretical chemistry teams, as well as the purposes guiding the research programs, are discussed. The published papers, the conferences, the congress communications and the thesis, are also reported

  16. Application of Fenton heterogeneous dog hair solid catalyst in decoloration of simulated reactive dye wastewater%非均相Fenton狗毛固体催化剂在活性染料模拟废染液脱色中的应用研究

    Institute of Scientific and Technical Information of China (English)

    陈晨晓; 王雪燕

    2014-01-01

    以狗毛作为催化剂载体,采用浸渍法负载Fe3+,制备了非均相Fenton反应催化剂,并将其用于催化活性蓝M-B模拟废染液的脱色.结果表明:在初始染料质量浓度为100 mg/L的50 mL模拟废染液中,添加Fe3+吸附量为33.0 mg/g的狗毛非均相Fenton反应催化剂0.4 g以及30%的H2O20.4 mL/L,脱色液pH控制在6左右,室温(25℃)下,脱色反应120 min,活性蓝M-B脱色率可达85%.%Fenton reaction heterogeneous catalyst was prepared using dog hair as the catalyst carrier with impregnation method loading Fe3+, which was catalyzed the decoloration of Reactive Blue M-B simulated dye wastewater. The experimental results showed that: the initial dye concentration was 100 mg/L of simulat-ed waste dye 50 mL, addition 0.4 g of heterogeneous Fenton catalyst dog hair with 33.0 mg/g of Fe3+ adsorp-tion amount and 0.4 mL/L of 30% H2O2, decoloration solution pH was control ed at about 6, reacted at room temperature (25℃) for 120 min, the decoloration rate of Reactive Blue M-B could reach 85%.

  17. Fenton-双泥SBR工艺深度处理难降解反渗透浓缩液%Intensive treatment of biorecalcitrant concentrated leachate effluent of reverse osmosis(RO) by Fenton-two sludge SBR system

    Institute of Scientific and Technical Information of China (English)

    覃芳慧; 叶秀雅; 吴彦瑜; 郑可; 彭华平; 周少奇

    2011-01-01

    采用Fenton试剂处理反渗透浓缩渗滤液(简称浓缩液),并探讨了双泥SBR工艺对Fenton处理后浓缩液与人工配水混合处理的可行性.结果表明,Fenton氧化对COD、TN和NH3-N的平均去除率分别为43.5%、22.5%和19.5%.对溶解性有机物(DOMs)的去除率为52.5%,其中胡敏酸(HA)、富里酸(FA)和亲水性有机物(HyI)的去除率分别为57.9%、59.4%和21.1%.双泥SBR系统对Fenton处理后浓缩液与生活污水的混合液处理效果较好,对COD、NH3-N、TN和腐殖酸的平均去除率分别为85%,75%,70%和70%.Fenton氧化和SBR联用,能有效处理难生物降解的浓缩液.%The treatment of concentrated leachate rejected from reverse osmosis (RO) with Fenton reagent was investigated, and the feasibility of treating mixture of landfill leachate and synthetic wastewater was studied using two-sludge SBR systems. The results showed that the average removal efficiencies for COD, TN and NH3-N were 43.5% , 22.5% and 19.5% , respectively. The removal rates for dissolved organic materials (DOMs) ,humic acid(HA) , fulvic acid(FA) and hydrophilic fraction were 52.5% ,57.9% ,59.4% and 21.1% ,respectively. The two-sludge SBR system had a favorable treatment efficiency of mixture of liquids, and the average removal efficiencies for COD, NH3-N, TN and humic substances were 85% ,75% ,70% and 70% , respectively. The combined advanced treatment of Fenton oxidation process followed two-sludge SBR could effectively treat bio-refractory contaminants in concentrated leachate.

  18. Rapid degradation of p-arsanilic acid with simultaneous arsenic removal from aqueous solution using Fenton process.

    Science.gov (United States)

    Xie, Xiande; Hu, Yuanan; Cheng, Hefa

    2016-02-01

    Although banned in some developed countries, p-arsanilic acid (p-ASA) is still used widely as a feed additive for swine production in many countries. With little uptake and transformation in animal bodies, nearly all the p-ASA administered to animals is excreted chemically unchanged in animal wastes, which can subsequently release the more toxic inorganic arsenic species upon degradation in the environment. For safe disposal of the animal wastes laden with p-ASA, we proposed a method of leaching the highly water-soluble p-ASA out of the manure first, followed by treatment of the leachate using the Fenton process to achieve fast oxidation of p-ASA and removal of the inorganic arsenic species released (predominantly arsenate) from solution simultaneously. The effects of solution pH, dosages of H2O2 and Fe(2+), and the presence of dissolved organic matter (DOM) on the treatment efficiency were systematically investigated. Under the optimum treatment conditions (0.53 mmol L(-1) Fe(2+), 2.12 mmol L(-1) H2O2, and initial pH of 3.0), p-ASA (10 mg-As L(-1)) could be completely oxidized to As(V) within 30 min in pure water and 4 natural water samples, and at the final pH of 4.0, the residual arsenic levels in solution phase were as low as 1.1 and 20.1-43.4 μg L(-1) in the two types of water matrixes, respectively. The presence of humic acid significantly retarded the oxidation of p-ASA by scavenging HO, and inhibited the As(V) removal through competitive adsorption on ferric hydroxide. Due to the high contents of DOM in the swine manure leachate samples (TOC at ∼500 mg L(-1)), much higher dosages of Fe(2+) (10.0 mmol L(-1)) and H2O2 (40.0 mmol L(-1)) and a longer treatment time (120 min) were required to achieve near complete oxidation of p-ASA (98.0%), while maintaining the levels of residual arsenic in the solution at products detected. Together, the results demonstrate that the Fenton process is promising as an efficient, robust, and low-cost treatment

  19. Tantalum (oxy)nitrides: Preparation, characterisation and enhancement of photo-Fenton-like degradation of atrazine under visible light

    Energy Technology Data Exchange (ETDEWEB)

    Du, Yingxun, E-mail: yxdu@niglas.ac.cn [Nanjing Institute of Geography and Limnology, State Key Laboratory of Lake Science and Environment, Chinese Academy of Sciences, Nanjing 210008 (China); Zhao, Lu; Su, Yaling [Nanjing Institute of Geography and Limnology, State Key Laboratory of Lake Science and Environment, Chinese Academy of Sciences, Nanjing 210008 (China)

    2011-11-15

    Highlights: {yields} The photocatalytic activity of TaON for Fe{sup 3+} reduction is higher than that of Ta{sub 3}N{sub 5}. {yields} Atrazine degradation was accelerated significantly by tantalum (oxy)nitrides sample. {yields} The regenerated catalyst displays considerably stable performance for atrazine degradation. - Abstract: Tantalum (oxy)nitrides were prepared by the nitridation of Ta{sub 2}O{sub 5} and were added to a photo-Fenton-like system to enhance Fe{sup 3+} reduction and atrazine degradation under visible light. The samples were characterized by XRD, XPS, DRS and BET analyses. XPS analysis showed that the nitrogen content of the tantalum (oxy)nitride samples increased noticeably with the nitridation temperature and nitridation time but slightly with the flow rate of NH{sub 3}. XRD results showed Ta{sub 2}O{sub 5} was first converted to TaON and then to Ta{sub 3}N{sub 5} when the nitridation temperature increased. DRS analysis showed that the sample obtained at 800 {sup o}C displayed the strongest absorption of visible light. However, the ability of the tantalum (oxy)nitrides to reduce Fe{sup 3+} did not increase continuously with the nitrogen content. Sample 7 (700 {sup o}C, Q{sub NH{sub 3}}=0.3L/min, 6 h) showed the highest level of photocatalytic activity for Fe{sup 3+} reduction. This is because the photocatalytic activity of TaON for Fe{sup 3+} reduction is higher than that of Ta{sub 3}N{sub 5}. And a slight synergetic effect was observed between TaON and Ta{sub 3}N{sub 5}. With the addition of sample 7, H{sub 2}O{sub 2} decomposition and atrazine degradation were significantly accelerated in a photo-Fenton-like system under visible light. The regenerated tantalum (oxy)nitrides catalyst displayed considerably stable performance for atrazine degradation.

  20. Tantalum (oxy)nitrides nanotube arrays for the degradation of atrazine in vis-Fenton-like process

    Energy Technology Data Exchange (ETDEWEB)

    Du, Yingxun, E-mail: yxdu@niglas.ac.cn [Nanjing Institute of Geography and Limnology, State Key Laboratory of Lake Science and Environment, Chinese Academy of Sciences, Nanjing 210008 (China); Zhao, Lu [Nanjing Institute of Geography and Limnology, State Key Laboratory of Lake Science and Environment, Chinese Academy of Sciences, Nanjing 210008 (China); Chang, Yuguang [School of Biochemical and Environmental Engineering, Nanjing Xiaozhuang Univeristy, Nanjing 211171 (China); Su, Yaling [Nanjing Institute of Geography and Limnology, State Key Laboratory of Lake Science and Environment, Chinese Academy of Sciences, Nanjing 210008 (China)

    2012-07-30

    Highlights: Black-Right-Pointing-Pointer Tantala nanotubes on a Ta foil were formed by anodization in a NH{sub 4}F-containing electrolyte. Black-Right-Pointing-Pointer Tantalum (oxy)nitrides nanotubes were active for Fe{sup 3+} reduction under visible light. Black-Right-Pointing-Pointer Atrazine degradation by {center_dot}OH was accelerated with tantalum (oxy)nitrides nanotubes. Black-Right-Pointing-Pointer Tantalum (oxy)nitrides nanotubes display stable performance for atrazine degradation. - Abstract: In order to overcome the limitation of the application of nanoparticles, tantalum (oxy)nitrides nanotube arrays on a Ta foil were synthesized and introduced in vis (visible light)-Fenton-like system to enhance the degradation of atrazine. At first, the anodization of tantalum foil in a mild electrolyte solution containing ethylene glycol and water (v:v = 2:1) plus 0.5 wt.% NH{sub 4}F produced tantala nanotubes with an average diameter of 30 nm and a length of approximately 1 {mu}m. Then the nitridation of tantala nanotube arrays resulted in the replacement of N atoms to O atoms to form tantalum (oxy)nitrides (TaON and Ta{sub 3}N{sub 5}), as testified by XRD and XPS analyses. The synthesized tantalum (oxy)nitrides nanotubes absorb well in the visible region up to 600 nm. Under visible light, tantalum (oxy)nitrides nanotube arrays were catalytically active for Fe{sup 3+} reduction. With tantalum (oxy)nitrides nanotube arrays, the degradation of atrazine and the formation of the intermediates in vis/Fe{sup 3+}/H{sub 2}O{sub 2} system were significantly accelerated. This was explained by the higher concentration of Fe{sup 2+} and thus the faster decomposition of H{sub 2}O{sub 2} with tantalum (oxy)nitrides nanotubes. In addition, tantalum (oxy)nitrides nanotubes exhibited stable performance during atrazine degradation for three runs. The good performance and stability of the tantalum (oxy)nitrides nanotubes film with the convenient separation, suggest that this film is

  1. 零价铁-Fenton氧化法预处理医药化工废水%Pre-treatment of pharmaceutical and chemical wastewater by Fenton oxidation with zero-valent iron

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    研究用零价铁(Fe0)/双氧水(H2O2)-Fenton氧化法预处理医药化工废水.考察不同初始参数如初始pH、H2O2浓度、Fe0用量、废水初始TOC浓度、温度等对废水TOC去除率的影响.试验结果表明,在初始pH值为3.0、H2O2/TOC摩尔比为2、Fe0用量为12.0 g/L,废水初始TOC浓度为1.0 g/L和反应温度25℃的条件下,反应60 min后,废水TOC的去除率为75.5%.酸性条件和提高温度均有利于反应的进行.研究表明,曝气/Fe0/H2O2系统可作为一种有效去除医药化工废水中有机污染物的预处理方法.①%The pre-treatment of pharmaceutical and chemical wastewater by Fenton oxidation with zero-valent iron (Fe0) and hydrogen peroxide (H2O2) was investigated. The influence of different crucial parameters such as the initial pH value,initial H2O2 concentration,the Fe0 dosage,initial TOC concentration of wastewater and the reaction temperature on TOC removal were evaluated. The results showed that 77.5%removal efficiency of TOC after 60 min reaction was achieved under the condition of the initial pH of 3.0,H2O2/TOC molar ratio of 2,Fe0 dosage of 12.0 g/L,initial TOC concentration of 1.0 g/L,the reaction temperature of 25℃. Acidic conditions and higher reaction temperature were favorable for TOC degradation. The study shows that the air/Fe0/H2O2 system can be considered as an effective alternative solution for the removal of many organic pollutants present in pharmaceutical and chemical wastewater.

  2. Extrusion of Fe2O3/SBA-15 mesoporous material for application as heterogeneous Fenton-like catalyst

    Directory of Open Access Journals (Sweden)

    María Isabel Pariente

    2015-03-01

    Full Text Available The aim of this work has been the extrusion of powder Fe2O3/SBA-15 catalyst in order to be successfully used in continuous catalytic fixed bed reactors as Fenton-like catalyst. The extrusion method was optimised using an amorphous silica material of similar properties than the Fe2O3/SBA-15 catalyst. The main studied variable was the composition of the extrusion paste using bentonite and methylcellulose as inorganic and organic binders, respectively. The organic content displayed a significant influence on the mechanical strength and specific surface area of the final extrudates. In contrast, the inorganic binder content hardly affected the final properties (in the studied range. The extruded Fe2O3/SBA-15 material showed a remarkable mechanical strength as well as the typical mesoporous structure of Fe2O3/SBA-15 with a relevant specific surface area (264 m2/g. The extruded catalyst achieved a high catalytic performance in the catalytic wet peroxide oxidation of phenol with a 60 % of total organic carbon reduction in both batch and continuous processes.

  3. Packed-bed column biosorption of chromium(VI) and nickel(II) onto Fenton modified Hydrilla verticillata dried biomass.

    Science.gov (United States)

    Mishra, Ashutosh; Tripathi, Brahma Dutt; Rai, Ashwani Kumar

    2016-10-01

    The present study represents the first attempt to investigate the biosorption potential of Fenton modified Hydrilla verticillata dried biomass (FMB) in removing chromium(VI) and nickel(II) ions from wastewater using up-flow packed-bed column reactor. Effects of different packed-bed column parameters such as bed height, flow rate, influent metal ion concentration and particle size were examined. The outcome of the column experiments illustrated that highest bed height (25cm); lowest flow rate (10mLmin(-1)), lowest influent metal concentration (5mgL(-1)) and smallest particle size range (0.25-0.50mm) are favourable for biosorption. The maximum biosorption capacity of FMB for chromium(VI) and nickel(II) removal were estimated to be 89.32 and 87.18mgg(-1) respectively. The breakthrough curves were analyzed using Bed Depth Service Time (BDST) and Thomas models. The experimental results obtained agree to both the models. Column regeneration experiments were also carried out using 0.1M HNO3. Results revealed good reusability of FMB during ten cycles of sorption and desorption. Performance of FMB-packed column in treating secondary effluent was also tested under identical experimental conditions. Results demonstrated significant reduction in chromium(VI) and nickel(II) ions concentration after the biosorption process. PMID:27400422

  4. Bifunctional composite from spent "Cyprus coffee" for tetracycline removal and phenol degradation: Solar-Fenton process and artificial neural network.

    Science.gov (United States)

    Oladipo, Akeem Adeyemi; Abureesh, Mosab Ali; Gazi, Mustafa

    2016-09-01

    Removals of tetracycline and photocatalytic degradation of phenol by Fe3O4/coffee residue (MCC) were investigated. Brunauer-Emmett-Teller (BET), vibrating sample magnetometer (VSM) and Boehm titration were employed to characterize MCC. Artificial neural network (ANN) model was developed to predict the tetracycline (TC) concentration in the column effluent. Maximum tetracycline adsorption capacity of 285.6mg/g was observed in a batch system. High removal efficiency (87%) was obtained at 3.3mL/min flow rate, 8.0cm bed height and 50mg/L influent TC concentration in a column system. Complete degradation of phenol by solar-Fenton was attained at 60min irradiation time. Total organic carbon (TOC) removal increased to 63.3% in the presence of 1.0g/L MCC, 1.2g/L H2O2 and solar irradiation. MCC showed remarkable potential to remove antibiotics from wastewater even in the presence of heavy metal (Ni(2+)) via magnetic separation. PMID:26318220

  5. Enzymatic in-situ generation of H2O2 for decolorization of Acid Blue 113 by fenton process

    Directory of Open Access Journals (Sweden)

    Karimi Afzal

    2012-01-01

    Full Text Available Decolorization of Acid Blue 113 in an aqueous medium by bio-Fenton process has been investigated in this research. Enzymatic oxidation of glucose was performed to in-situ generation of H2O2 which was employed to react with Fe2+ for producing hydroxyl radicals. The effect of various parameters include concentrations of 113, glucose, and FeSO4, activity of glucose oxidase (GOx and the effect of pH were assessed. The highest decolorization of AB 113 were achieved at Fe2+ concentration of 0.2 mmol/L, pH =4.0, glucose concentration of 0.018 mol/L, and glucose oxidase activity of 2500 U/L in the constant temperature (23 ±0.1ºC and constant shaking rate (160 r/min, while the concentration of 113 was 40 mg/L. In these conditions, 113 decolorization efficiency after 60 min was obtained about 95%.

  6. Modeling and optimization of heterogeneous photo-Fenton process with response surface methodology and artificial neural networks.

    Science.gov (United States)

    Kasiri, M B; Aleboyeh, H; Aleboyeh, A

    2008-11-01

    In this study, estimation capacities of response surface methodology (RSM) and artificial neural network (ANN) in a heterogeneous photo-Fenton process were investigated. The zeolite Fe-ZSM5 was used as heterogeneous catalyst of the process for degradation of C.I. Acid Red 14 azo dye. The efficiency of the process was studied as a function of four independent variables, concentration of the catalyst, molar ratio of initial concentration of H2O2 to that of the dye (H value), initial concentration of the dye and initial pH of the solution. First, a central composite design (CCD) and response surface methodology were used to evaluate simple and combined effects of these parameters and to optimize process efficiency. Satisfactory prediction second-order regression was derived by RSM. Then, the independent parameters were fed as inputs to an artificial neural network while the output of the network was the degradation efficiency of the process. The multilayer feed-forward networks were trained by the sets of input-output patterns using a backpropagation algorithm. Comparable results were achieved for data fitting by using ANN and RSM. In both methods, the dye mineralization process was mainly influenced by pH and the initial concentration of the dye, whereas the other factors showed lower effects. PMID:19031889

  7. Automatic dosage of hydrogen peroxide in solar photo-Fenton plants: development of a control strategy for efficiency enhancement.

    Science.gov (United States)

    Ortega-Gómez, E; Moreno Úbeda, J C; Alvarez Hervás, J D; Casas López, J L; Santos-Juanes Jordá, L; Sánchez Pérez, J A

    2012-10-30

    The solar photo-Fenton process is widely used for the elimination of pollutants in aqueous effluent and, as such, is amply cited in the literature. In this process, hydrogen peroxide represents the highest operational cost. Up until now, manual dosing of H(2)O(2) has led to low process performance. Consequently, there is a need to automate the hydrogen peroxide dosage for use in industrial applications. As it has been demonstrated that a relationship exists between dissolved oxygen (DO) concentration and hydrogen peroxide consumption, DO can be used as a variable in optimising the hydrogen peroxide dosage. For this purpose, a model was experimentally obtained linking the dynamic behaviour of DO to hydrogen peroxide consumption. Following this, a control system was developed based on this model. This control system - a proportional and integral controller (PI) with an anti-windup mechanism - has been tested experimentally. The assays were carried out in a pilot plant under sunlight conditions and with paracetamol used as the model pollutant. In comparison with non-assisted addition methods (a sole initial or continuous addition), a decrease of 50% in hydrogen peroxide consumption was achieved when the automatic controller was used, driving an economic saving and an improvement in process efficiency. PMID:22954603

  8. Removal of color from real dyeing wastewater by Electro-Fenton technology using a three-dimensional graphite cathode

    International Nuclear Information System (INIS)

    This work investigates the removal of color from wastewater that contains low dyestuff concentrations by the Electro-Fenton process. The color was removed by in situ electrogenerated hydrogen peroxides at a three-dimensional graphite cathode with added ferrous sulfates. Experimental runs were conducted to evaluate the effect of the operating parameters, such as the oxygen contact mode, the oxygen sparging rate, the applied current density, the concentration of ferrous ions, the solution temperature and the pH among others, on the removal of color. The removal efficiency of the color in the cathodic chamber reached 70.6% under specified operation conditions in 150 min. The removal efficiency was controlled by the mass transfer when the oxygen-sparging rate was less than 0.3 dm3/min for the reactor configuration herein. The optimal applied current density was 68 A/m2 when the energy consumption was considered. The highest removal efficiency was obtained by adding 20 mM Fe(II) to the solution. The optimal solution pH was 3 in this work. The temperature negatively affected color removal

  9. Solar photo-Fenton using peroxymonosulfate for organic micropollutants removal from domestic wastewater: comparison with heterogeneous TiO₂ photocatalysis.

    Science.gov (United States)

    Ahmed, Moussa Mahdi; Brienza, Monica; Goetz, Vincent; Chiron, Serge

    2014-12-01

    This work aims at decontaminating biologically treated domestic wastewater effluents from organic micropollutants by sulfate radical based (SO4(-)) homogeneous photo-Fenton involving peroxymonosulfate as an oxidant, ferrous iron (Fe(II)) as a catalyst and simulated solar irradiation as a light source. This oxidative system was evaluated by using several probe compounds belonging to pesticides (bifenthrin, mesotrione and clothianidin) and pharmaceuticals (diclofenac, sulfamethoxazole and carbamazepine) classes and its kinetic efficiency was compared to that to the well known UV-Vis/TiO2 heterogeneous photocatalysis. Except for carbamazepine, apparent kinetic rate constants were always 10 times higher in PMS/Fe(II)/UV-Vis than in TiO2/UV-Vis system and more than 70% of total organic carbon abatement was reached in less than one hour treatment. Hydroxyl radical (OH) and SO4(-) reactivity was investigated using mesotrione as a probe compound through by-products identification by liquid chromatography-high resolution-mass spectrometry and transformation pathways elucidation. In addition to two OH based transformation pathways, a specific SO4(-) transformation pathway which first involved degradation through one electron transfer oxidation processes followed by decarboxylation were probably responsible for mesotrione degradation kinetic improvement upon UV-Vis/PMS/Fe(II) system in comparison to UVVis/TiO2 system. PMID:25108605

  10. Nuclear reactions

    International Nuclear Information System (INIS)

    Nuclear reactions' marks a new development in the study of television as an agency of public policy debate. During the Eighties, nuclear energy became a major international issue. The disasters at Three-mile Island and Chernobyl created a global anxiety about its risks and a new sensitivity to it among politicians and journalists. This book is a case-study into documentary depictions of nuclear energy in television and video programmes and into the interpretations and responses of viewers drawn from many different occupational groupings. How are the complex and specialist arguments about benefit, risk and proof conveyed through the different conventions of commentary, interview and film sequence? What symbolic associations does the visual language of television bring to portrayals of the issue? And how do viewers make sense of various and conflicting accounts, connecting what they see and hear on the screen with their pre-existing knowledge, experience and 'civic' expectations. The authors examine some of the contrasting forms and themes which have been used by programme makers to explain and persuade, and then give a sustained analysis of the nature and sources of viewers' own accounts. 'Nuclear Reactions' inquires into the public meanings surrounding energy and the environment, spelling out in its conclusion some of the implications for future media treatments of this issue. It is also a key contribution to the international literature on 'television knowledge' and the processes of active viewing. (author)

  11. Estudo da degradação de ranitidina via H2O2 eletrogerado/Fenton em um reator eletroquímico com eletrodos de difusão gasosa Study of the ranitidine degradation by H2O2 electrogenerated/Fenton in a electrochemical reactor with gas diffusion electrode

    Directory of Open Access Journals (Sweden)

    André A. G. F. Beati

    2009-01-01

    Full Text Available The study of the electrochemical degradation of the ranitidine was developed using an electrochemical reactor with a gas diffusion electrode (GDE as cathode. The electrolysis experiments was performed at constant current (1 4 A. The process reached a production of 630 mg L-1 of the H2O2 at 7 A. The ranitidine concentrations was reduced in 99.9% (HPLC and chemical oxygen demand (COD was reduced in 86.7% by electro-Fenton.

  12. Potential of Wood-Rotting Fungi to Attack Polystyrene Sulfonate and Its Depolymerisation by Gloeophyllum trabeum via Hydroquinone-Driven Fenton Chemistry.

    Directory of Open Access Journals (Sweden)

    Martin C Krueger

    Full Text Available Synthetic polymers often pose environmental hazards due to low biodegradation rates and resulting accumulation. In this study, a selection of wood-rotting fungi representing different lignocellulose decay types was screened for oxidative biodegradation of the polymer polystyrene sulfonate (PSS. Brown-rot basidiomycetes showed PSS depolymerisation of up to 50 % reduction in number-average molecular mass (Mn within 20 days. In-depth investigations with the most efficient depolymeriser, a Gloeophyllum trabeum strain, pointed at extracellular hydroquinone-driven Fenton chemistry responsible for depolymerisation. Detection of hydroxyl radicals present in the culture supernatants showed good compliance with depolymerisation over the time course of PSS degradation. 2,5-Dimethoxy-1,4-hydroquinone (2,5-DMHQ, which was detected in supernatants of active cultures via liquid chromatography and mass spectrometry, was demonstrated to drive the Fenton processes in G. trabeum cultures. Up to 80% reduction in Mn of PSS where observed when fungal cultures were additionally supplemented with 2,5-dimethoxy benzoquinone, the oxidized from of 2,5-DMHQ. Furthermore, 2,5-DMHQ could initiate the Fenton's reagent-mediated PSS depolymerisation in cell-free systems. In contrast, white-rot fungi were unable to cause substantial depolymerising effects despite the expression of lignin-modifying exo-enzymes. Detailed investigations with laccase from Trametes versicolor revealed that only in presence of certain redox mediators limited PSS depolymerisation occurred. Our results indicate that brown-rot fungi might be suitable organisms for the biodegradation of recalcitrant synthetic polymeric pollutants.

  13. Impacts of operating parameters on oxidation-reduction potential and pretreatment efficacy in the pretreatment of printing and dyeing wastewater by Fenton process

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Huifang, E-mail: whfkhl@sina.com [College of Environment, Jiangsu Key Laboratory of Industrial Water-Conservation and Emission Reduction, Nanjing University of Technology, Nanjing 210009 (China); Wang, Shihe [Department of Municipal Engineering, Southeast University, Nanjing 210096 (China)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer A real printing and dyeing wastewater was pretreated by Fenton process. Black-Right-Pointing-Pointer We investigated impacts of operating parameters on ORP and pretreatment efficacy. Black-Right-Pointing-Pointer Relationship among ORP, operating parameters and treatment efficacy was established. Black-Right-Pointing-Pointer Pretreatment efficacy was in proportion to the exponent of temperature reciprocal. Black-Right-Pointing-Pointer We investigated kinetics of color and COD removal and BOD{sub 5}/COD ratio in solution. - Abstract: An experiment was conducted in a batch reactor for a real printing and dyeing wastewater pretreatment using Fenton process in this study. The results showed that original pH, hydrogen peroxide concentration and ferrous sulfate concentration affected ORP value and pretreatment efficacy greatly. Under experimental conditions, the optimal original pH was 6.61, and the optimal hydrogen peroxide and ferrous sulfate concentrations were 1.50 and 0.75 g L{sup -1}, respectively. The relationship among ORP, original pH, hydrogen peroxide concentration, ferrous sulfate concentration, and color (COD or BOD{sub 5}/COD) was established, which would be instructive in on-line monitoring and control of Fenton process using ORP. In addition, the effects of wastewater temperature and oxidation time on pretreatment efficacy were also investigated. With an increase of temperature, color and COD removal efficiencies and BOD{sub 5}/COD ratio increased, and they were in proportion to the exponent of temperature reciprocal. Similarly, color and COD removal efficiencies increased with increasing oxidation time, and both color and COD removal obeyed the first-order kinetics. The BOD{sub 5}/COD ratio could be expressed by a second-degree polynomial with respect to oxidation time, and the best biodegradability of wastewater was present at the oxidation time of 6.10 h.

  14. Abatement of phenolic mixtures by catalytic wet oxidation enhanced by Fenton's pretreatment: Effect of H2O2 dosage and temperature

    International Nuclear Information System (INIS)

    Catalytic wet oxidation (CWO) of a phenolic mixture containing phenol, o-cresol and p-cresol (500 mg/L on each pollutant) has been carried out using a commercial activated carbon (AC) as catalyst, placed in a continuous three-phase reactor. Total pressure was 16 bar and temperature was 127 deg. C. Pollutant conversion, mineralization, intermediate distribution, and toxicity were measured at the reactor outlet. Under these conditions no detoxification of the inlet effluent was found even at the highest catalyst weight (W) to liquid flow rate (QL) ratio used. On the other hand, some Fenton Runs (FR) have been carried out in a batch way using the same phenolic aqueous mixture previously cited. The concentration of Fe2+ was set to 10 mg/L. The influence of the H2O2 amount (between 10 and 100% of the stoichiometric dose) and temperature (30, 50, and 70 deg. C) on phenols conversion, mineralization, and detoxification have been analyzed. Phenols conversion was near unity at low hydrogen peroxide dosage but mineralization and detoxification achieved an asymptotic value at each temperature conditions. The integration of Fenton reagent as pretreatment of the CWO process remarkably improves the efficiency of the CWO reactor and allows to obtain detoxified effluents at mild temperature conditions and relatively low W/QL values. For a given phenolic mixture a temperature range of 30-50 deg. C in the Fenton pretreatment with a H2O2 dosage between 20 and 40% of the stoichiometric amount required can be proposed

  15. Application of Photo-Fenton Process for COD Removal from Wastewater Produced from Surfactant-Washed  Oil-Contaminated (TPH Soils

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Mehrasbi

    2012-10-01

    Full Text Available Backgrounds and Objectives: The base structure of total petroleum hydrocarbons (TPH is made of hydrogen and carbon. Widespread use, improper disposal and accidental spills of this compounds lead to long term remaining of contaminations such as organic solvents and poly aromatic hydrocarbons (PAHs in the soil and groundwater resources, resulting in critical environmental issues. In this study, an oil-contaminated soil was washed using Tween 80 surfactant and the application of photo-Fenton process (UV/Fe2+/H2O2 for treatment of the produced wastewater was evaluated. Materials and Methods: Tween 80 is a yellow liquid with high viscosity and soluble in water. In order to determine of the photo-Fenton process efficiency, we studied effective variables