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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 recalcitrant compounds by catechol-driven Fenton reaction

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, J.; Contreras, D.; Oviedo, C.; Freer, J.; Baeza, J. [Renewable Resources Lab., Univ. de Concepcion, Concepcion (Chile)

    2003-07-01

    Dihydroxybenzenes are able to reduce Fe(III) and promote fenton reaction. The Catechol/Fe(III)/H{sub 2}O{sub 2} system has been successfully used to degrade different compounds, being in all cases more efficient than Fe(II)-Fenton reaction. In this paper the possibilities for using the catechol-driven fenton reaction to degrade recalcitrant compounds such as Fe(III)-EDTA complex and veratryl alcohol are reviewed. (orig.)

  3. Zn-edta degradation by catechol-driven fenton reaction

    Directory of Open Access Journals (Sweden)

    Claudia Oviedo

    2012-01-01

    Full Text Available Zn-EDTA degradabilty by catechol-driven Fenton reaction was studied. Response surface methodology central composite design was employed to maximize this complex degradation. Theoretical speciation calculations were in good agreement with the experimental results. Fenton and Fenton type treatments are typically thought to be applicable only in the highly acidic range, representing a major operational constraint. Interestingly, at optimized concentrations, this CAT-driven Fenton reaction at pH 5.5 achieved 100% Zn-EDTA degradation; 60% COD and 17% TOC removals, using tiny amounts of CAT (50 µM, Fe(III (445 µM and H2O2 (20 mM with no evident ferric sludge.

  4. Photo-Fenton reaction using a nanocomposite

    Energy Technology Data Exchange (ETDEWEB)

    Yue Po Lock; Feng Jiyun; Hu Xijun [Hong Kong Univ. of Science and Technology (Hong Kong)

    2003-07-01

    A novel laponite RD clay-based Fe nanocomposite (Fe-Lap-RD) has been successfully prepared through a reaction between a solution of iron salt and an aqueous dispersion of laponite RD clay. The X-ray diffraction (XRD) results reveal that the Fe-Lap-RD mainly consists of Fe{sub 2}O{sub 3} and Fe{sub 2}SiO{sub 10}, which have tetragonal and monoclinic structures, respectively. The nanocomposite has a high specific surface area as well as a large pore volume. The photo-catalytic activity of the Fe-Lap-RD for the degradation of an organic azo dye Orange II was examined. It was found that the rate of mineralization of orange II was slower than that of decoloration. 70% total organic carbon (TOC) of 0.2 mM orange II can be removed in 90 minutes. (orig.)

  5. 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.

  6. Degradation of anthraquinone dye reactive blue 4 in pyrite ash catalyzed Fenton reaction.

    Science.gov (United States)

    Becelic-Tomin, Milena; Dalmacija, Bozo; Rajic, Ljiljana; Tomasevic, Dragana; Kerkez, Djurdja; Watson, Malcolm; Prica, Miljana

    2014-01-01

    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.

  7. 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.

  8. Drinking water and biofilm disinfection by Fenton-like reaction.

    Science.gov (United States)

    Gosselin, F; Madeira, L M; Juhna, T; Block, J C

    2013-10-01

    A Fenton-like disinfection process was conducted with Fenton's reagent (H2O2) at pH 3 or 5 on autochthonous drinking water biofilms grown on corroded or non-corroded pipe material. The biofilm disinfection by Fenton-like oxidation was limited by the low content of iron and copper in the biomass grown on non-corroded plumbing. It was slightly improved by spiking the distribution system with some additional iron source (soluble iron II or ferrihydrite particles appeared as interesting candidates). However successful in situ disinfection of biofilms was only achieved in fully corroded cast iron pipes using H2O2 and adjusting the pH to 5. These new results provide additional support for the use of Fenton's processes for cleaning drinking water distribution systems contaminated with biological agents or organics.

  9. Development of a system for treatment of coconut industry wastewater using electrochemical processes followed by Fenton reaction.

    Science.gov (United States)

    Gomes, Lúcio de Moura; Duarte, José Leandro da Silva; Pereira, Nathalia Marcelino; Martínez-Huitle, Carlos A; Tonholo, Josealdo; Zanta, Carmen Lúcia de Paiva E Silva

    2014-01-01

    The coconut processing industry generates a significant amount of liquid waste. New technologies targeting the treatment of industrial effluents have emerged, including advanced oxidation processes, the Fenton reaction, and electrochemical processes, which produce strong oxidizing species to remove organic matter. In this study we combined the Fenton reaction and electrochemical process to treat wastewater generated by the coconut industry. We prepared a synthetic wastewater consisting of a mixture of coconut milk and water and assessed how the Fenton reagents' concentration, the cathode material, the current density, and the implementation of associated technologies affect its treatment. Electrochemical treatment followed by the Fenton reaction diminished turbidity and chemical oxygen demand (COD) by 85 and 95%, respectively. The Fenton reaction followed by the electrochemical process reduced turbidity and COD by 93 and 85%, respectively. Therefore, a combination of the Fenton and electrochemical technologies can effectively treat the effluent from the coconut processing industry.

  10. Decolorization and degradation of dyes with mediated fenton reaction.

    Science.gov (United States)

    Goodell, Barry; Qian, Yuhui; Jellison, Jody; Richard, Mike

    2004-01-01

    A mediated Fenton system has been evaluated for decolorization of several types of dyes. The result shows that the Fenton system with a dihydroxybenzoic acid (DHBA) chelator-mediator effectively reduced the color of a diluted solution of Carta Yellow RW liquid, Carta Yellow G liquid, and Cartasol Red 2GF liquid dye to a colorless level after 90 minutes of treatment with 100 microM iron II (Fe[II]), 100 microM DHBA, and 10 mM hydrogen peroxide (H2O2) at room temperature. Our results show that compared to a neat Fenton process, the mediated Fenton decolorization process increased the production, and therefore the effective longevity, of hydroxyl radical (OH) species to increase the decolorization efficiency. Our results suggest that application of this system would also result in an increase in dissolved oxygen (DO) in solution, which in turn would result in reduction of chemical oxygen demand (COD), biochemical oxygen demand (BOD), and total organic carbon (TOC).

  11. Fenton-like reaction: a possible way to efficiently remove illicit drugs and pharmaceuticals from wastewater.

    Science.gov (United States)

    Mackuľak, Tomáš; Mosný, Michal; Grabic, Roman; Golovko, Oksana; Koba, Olga; Birošová, Lucia

    2015-03-01

    We analyzed 13 psychoactive pharmaceuticals, illicit drugs and their metabolites in wastewater treatment plant influent and effluent and the possibility of their degradation by biological and chemical processes. Tramadol (413-853 ng/L) and methamphetamine (460-682 ng/L) were the most concentrated compounds in the wastewater in winter and summer, respectively. A significant decrease in the concentration of tramadol in wastewater was measured during the summer. The lowest efficiency was observed for tramadol, venlafaxine, citalopram and oxazepam (∼ 10%) and the highest efficiency was observed for amphetamine and THC-COOH (∼ 80%). The efficiency of compound degradation via the Fenton reaction, a modified Fenton reaction and different degradation (by algae, wood-rotting fungi and enzymes at influent versus effluent) was determined. The Fenton reaction and its modification were efficient at eliminating these substances in comparison with the tested biological processes.

  12. Decolorization kinetics of Procion H-exl dyes from textile dyeing using Fenton-like reactions.

    Science.gov (United States)

    Ntampegliotis, K; Riga, A; Karayannis, V; Bontozoglou, V; Papapolymerou, G

    2006-08-10

    The decolorization kinetics of three commercially used Procion H-exl dyes was studied using a Fenton-like reagent. The effect of the major system parameters (pH, concentration of H(2)O(2) and Fe(3+) and initial dye concentration) on the kinetics was determined. For comparison, the effect of the use of UV irradiated Fenton-like reagent and of Fenton reagent on the kinetics was also examined. In addition, mineralization rates and the biodegradability improvement as well as the effect of the addition of Cl(-), CO(3)(2-) or HCO(3)(-) on the decolorization rates was studied. The reactions were carried out in a 300 ml stirred cylindrical reactor with the capability of UV irradiation. The dye half-life time goes through a minimum with respect to the solution pH between 3 and 4. It also exhibits a broad minimum with respect to Fe(3+) and H(2)O(2) at molar ratios of H(2)O(2)/Fe(3+) from about 100 to 10. The addition of CO(3)(2-) and HCO(3)(-) substantially reduces the decolorization rates, while this effect is significantly less pronounced with Cl(-). At an optimum range of parameters, the mineralization rate (TOC reduction) is very slow for the Fenton-like process (TOC decrease from an initial 49.5 to 41.1 mg/l after 30 min and to only 35.2 mg/l after 600 min), but it increases significantly for the photo-Fenton-like process (to TOC values of 39.7 and 11.4 mg/l, respectively). The biodegradability, as expressed by the BOD/COD ratio, increases significantly from an initial value of 0.11-0.55 for the Fenton-like and to 0.72 for the photo-Fenton-like processes.

  13. Simultaneous in situ generation of hydrogen peroxide and Fenton reaction over Pd-Fe catalysts

    OpenAIRE

    Yalfani, Mohammad S.; Contreras, Sandra; Llorca Piqué, Jordi; Domínguez Escalante, Montserrat; Sueiras, Jesús; Medina, Francesc

    2010-01-01

    High mineralization degree of organic compounds can be achieved by a novel environmentally-friendly full heterogeneous Pd–Fe catalytic system, which involves in situ generation of hydrogen peroxide from formic acid and oxygen, and oxidation of organic compounds by Fenton process in a one-pot reaction.

  14. Effects of Fenton Reaction on Human Serum Albumin: An In Vitro Study

    Science.gov (United States)

    Khosravifarsani, Meysam; Monfared, Ali Shabestani; Pouramir, Mahdi; Zabihi, Ebrahim

    2016-01-01

    Introduction Human serum albumin (HSA) is a critical protein in human blood plasma, which can be highly damaged by oxidative stress. The aim of this study was to analyze modifications of this protein after oxidation using a Fenton system. Methods In this 2015 experiment, different ratios of Fenton reagent (Fe2+/H2O2) was incubated with one concentration of human serum albumin (1mg/ml). Hence, HSA was incubated 30 min with various combinations of a Fenton system and quantified oxidation products such as carbonyl groups, fragmentations, degradations, and oxidized free thiol group using reliable techniques. Image and data analysis were carried out using ImageJ software and Excel (version 2007), respectively. Results An SDS-PAGE profile showed no cross link and aggregation. However, protein band intensity has decreased to 50% in the highest ratio of H2O2/Fe. Carbonylation assay indicated carbonyl/protein (molc/molp) ratio increased linearly in lower ratios and the values plateau at higher levels of H2O2/Fe 2+. The only free sulfhydryl group on HSA was oxidized in all ratios of the Fenton system. Conclusion To sum, the structure of HSA has been changed following treatment with Hydroxyl Radical as the main product of Fenton reaction. These data confirm the antioxidant activity of HSA.

  15. Comparison of TiO2 photocatalysis, electrochemically assisted Fenton reaction and direct electrochemistry for simulation of phase I metabolism reactions of drugs

    NARCIS (Netherlands)

    Ruokolainen, Miina; Gül, Turan; Permentier, Hjalmar; Sikanen, Tiina; Kostiainen, Risto; Kotiaho, Tapio

    2016-01-01

    The feasibility of titanium dioxide (TiO2) photocatalysis, electrochemically assisted Fenton reaction (EC-Fenton) and direct electrochemical oxidation (EC) for simulation of phase I metabolism of drugs was studied by comparing the reaction products of buspirone, promazine, testosterone and 7-ethoxyc

  16. Kinetics and reaction pathways of formaldehyde degradation using the UV-fenton method.

    Science.gov (United States)

    Liu, Xiangxuan; Liang, Jiantao; Wang, Xuanjun

    2011-05-01

    This study was based on the purpose of investigating the reaction rules of formaldehyde (HCHO) as an intermediate product in the degradation of many other organic wastewaters. The process conditions of UV-Fenton method for the degradation of the low concentrations of HCHO were studied in a batch photochemical reactor. The results showed that, when the original HCHO concentration was 30 mg/L, at an operating temperature of 23 degrees C, pH = 3, an H202 dosage of 68 mg/L, and an H2O2-to-Fe2+ mole ratio (H2O2:Fe2+) of 5, 91.89% of the HCHO was removed after 30 minutes. The degradation of HCHO in the UV-Fenton system was basically in accordance with the exponential decay. The kinetic study results showed that the reaction orders of HCHO, Fe2+, and H2O2 in the system were 1.054, 0.510, and 0.728, respectively, and the activation energy (Ea) was 9.85 kJ/mol. The comparison of UV/H2O2, Fenton, and UV-Fenton systems for the degradation of HCHO, and the results of iron catalyst tests showed that the mechanism of UV-Fenton on the degradation of HCHO was through a synergistic effect of Fe2+ and UV light to catalyze the decomposition of H2O2. The introduction of UV irradiation to the Fenton system largely increased the degradation rate of HCHO, mainly as a result of the accelerating effect on the formation of the Fe2+/Fe3+ cycle. The reaction products were analyzed by gas chromatography-mass spectrometry and a chemical oxygen demand (COD) analyzer. The effluent gases also were analyzed by gas chromatography. Based on those results, the reaction pathways of HCHO in the UV-Fenton system were proposed. The qualitative and quantitative analysis of the reaction products and the COD showed that the main intermediate product of the reaction was formic acid, and the further oxidation of it was the rate-limiting step for the degradation of HCHO.

  17. Discoloration of Rhodamine B dyeing wastewater by schorl-catalyzed Fenton-like reaction

    Institute of Scientific and Technical Information of China (English)

    Murari; PRASAD

    2009-01-01

    As other natural iron-bearing minerals, schorl could be taken as an effective iron source for degradation of organic pollutants by mineral-catalyzed Fenton-like system. In our present study, the schorl-catalyzed Fenton-like system has been successfully developed for discoloration of an active commercial dye, Rhodamine B (RhB), in an aqueous solution. Through a number of batch discoloration experiments under various conditions, it was found that the reactivity of the system increased by, respectively, increasing schorl dosage, temperature, hydrogen peroxide starting concentration and by decreasing the pH. Over 90% of discoloration ratio could be gained in less than 30 min, and nearly 70% of total organic carbon (TOC) could be removed in less than 200 min. And, the schorl catalyst could be repeatedly used at least ten times, still with high catalytic activity. Comparative studies indicated that the RhB discoloration ratios were much higher in presence of schorl and H2O2 than those in presence of schorl or H2O2 only, which suggested that the schorl-catalyzed Fenton-like reaction governed the RhB discoloration process. The content of Fe ion leaching in the solution was also measured using inductively coupling plasma-atomic emission spectra (ICP-AES). A mechanism proposed herein suggested that adsorption and Fenton-like reaction (heterogeneous and homogeneous) were responsible for the discoloration of RhB.

  18. Application of Fenton's reaction to steam explosion prehydrolysates from poplar biomass.

    Science.gov (United States)

    Oliva, J M; Manzanares, P; Ballesteros, I; Negro, M J; González, A; Ballesteros, M

    2005-01-01

    The application of Fenton's reaction to enhance the fermentability of prehydrolysates obtained from steam explosion pretreatment of poplar biomass was studied. Reaction conditions of temperature and H2O2 and Fe(II) concentrations were studied. The fermentability of prehydrolysate treated by Fenton's reaction was tested by using different inoculum sizes of thermotolerant strain Kluyveromyces marxianus CECT 10875. The highest percentages of toxic compound degradation (ranging from 71 to 93% removal) were obtained at the highest H2O2 concentration tested (50 mM). However, a negative effect on fermentability was observed at this H2O2 concentration at the lower inoculum loading. An increase in inoculum size to 0.6 g/L resulted in an enhanced ethanol fermentation yield of 95% relative to control.

  19. 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.

  20. 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.

  1. Decolorization kinetics of Procion H-exl dyes from textile dyeing using Fenton-like reactions

    Energy Technology Data Exchange (ETDEWEB)

    Ntampegliotis, K. [Department of Physical Sciences, Technological and Educational Institute of Larisa, T.K 411 10 Larisa (Greece); Riga, A. [Department of Physical Sciences, Technological and Educational Institute of Larisa, T.K 411 10 Larisa (Greece); Karayannis, V. [Department of Physical Sciences, Technological and Educational Institute of Larisa, T.K 411 10 Larisa (Greece); Bontozoglou, V. [Department of Mechanical and Industrial Engineering, University of Thessaly, Pedion Areos, T.K 383 34 Volos (Greece); Papapolymerou, G. [Department of Physical Sciences, Technological and Educational Institute of Larisa, T.K 411 10 Larisa (Greece)]. E-mail: papapoly@teilar.gr

    2006-08-10

    The decolorization kinetics of three commercially used Procion H-exl dyes was studied using a Fenton-like reagent. The effect of the major system parameters (pH, concentration of H{sub 2}O{sub 2} and Fe{sup 3+} and initial dye concentration) on the kinetics was determined. For comparison, the effect of the use of UV irradiated Fenton-like reagent and of Fenton reagent on the kinetics was also examined. In addition, mineralization rates and the biodegradability improvement as well as the effect of the addition of Cl{sup -}, CO{sub 3} {sup 2-} or HCO{sub 3} {sup -} on the decolorization rates was studied. The reactions were carried out in a 300 ml stirred cylindrical reactor with the capability of UV irradiation. The dye half-life time goes through a minimum with respect to the solution pH between 3 and 4. It also exhibits a broad minimum with respect to Fe{sup 3+} and H{sub 2}O{sub 2} at molar ratios of H{sub 2}O{sub 2}/Fe{sup 3+} from about 100 to 10. The addition of CO{sub 3} {sup 2-} and HCO{sub 3} {sup -} substantially reduces the decolorization rates, while this effect is significantly less pronounced with Cl{sup -}. At an optimum range of parameters, the mineralization rate (TOC reduction) is very slow for the Fenton-like process (TOC decrease from an initial 49.5 to 41.1 mg/l after 30 min and to only 35.2 mg/l after 600 min), but it increases significantly for the photo-Fenton-like process (to TOC values of 39.7 and 11.4 mg/l, respectively). The biodegradability, as expressed by the BOD/COD ratio, increases significantly from an initial value of 0.11-0.55 for the Fenton-like and to 0.72 for the photo-Fenton-like processes.

  2. Application of click chemistry conditions for 5-bromo-2'-deoxyuridine determination through Fenton and related reactions.

    Science.gov (United States)

    Cappella, Paolo; Pulici, Maurizio; Gasparri, Fabio

    2015-01-05

    Mixtures of ascorbate and copper used in certain click chemistry experimental conditions act as oxidizing agents, catalyzing the formation of reactive oxygen species through Fenton and related reactions. Hydroxyl radicals act as chemical nucleases, introducing DNA strand breaks that can be exploited for BrdU immunostaining in place of acid denaturation. This procedure is readily applicable to high content analysis and flow cytometry assays, and provides results comparable to click chemistry EdU cycloaddition and classical BrdU immunodetection. Importantly, this approach allows preservation of labile epitopes such as phosphoproteins. This unit describes an optimized method that successfully employs Fenton chemistry for simultaneous detection of phosphoproteins and BrdU in intact cells.

  3. Toxic DNA Damage by Hydrogen Peroxide through the Fenton Reaction in vivo and in vitro

    Science.gov (United States)

    Imlay, James A.; Chin, Sherman M.; Linn, Stuart

    1988-04-01

    Exposure of Escherichia coli to low concentrations of hydrogen peroxide results in DNA damage that causes mutagenesis and kills the bacteria, whereas higher concentrations of peroxide reduce the amount of such damage. Earlier studies indicated that the direct DNA oxidant is a derivative of hydrogen peroxide whose formation is dependent on cell metabolism. The generation of this oxidant depends on the availability of both reducing equivalents and an iron species, which together mediate a Fenton reaction in which ferrous iron reduces hydrogen peroxide to a reactive radical. An in vitro Fenton system was established that generates DNA strand breaks and inactivates bacteriophage and that also reproduces the suppression of DNA damage by high concentrations of peroxide. The direct DNA oxidant both in vivo and in this in vitro system exhibits reactivity unlike that of a free hydroxyl radical and may instead be a ferryl radical.

  4. Utilization of Fenton-like reaction for antibiotics and resistant bacteria elimination in different parts of WWTP.

    Science.gov (United States)

    Mackuľak, Tomáš; Nagyová, Kristína; Faberová, Milota; Grabic, Roman; Koba, Olga; Gál, Miroslav; Birošová, Lucia

    2015-09-01

    Utilization of relatively low-cost modification of Fenton reaction for the elimination of selected antibiotics and resistant coliforms in different part of wastewater treatment plant (WWTP) was studied. The concentration of antibiotics and occurrence of resistant gems in different stages of WWTP in the capital city of Slovakia - Bratislava was analyzed by LC-MS/MS technique. Consequently, Fenton-like reaction was applied for the elimination of chemical and biological contaminants. Comparative study with classical Fenton reaction was also done. Very high concentrations of clarithromycin, ciprofloxacin and azithromycin in influent water were found. Coliform bacteria were predominantly resistant to ampicillin, ciprofloxacin and gentamicin. After the mechanical stage, the concentration of antibiotics in water was significantly decreased because of the sorption during this step. Biological step degraded 12 types of antibiotics. Analyses of effluent water showed very bad elimination of azithromycin (919ng/L) and clarithromycin (684ng/L). Contrary, ciprofloxacin was removed with very high efficiency (95%). The number of resistant bacteria was also significantly decreased in effluent water. In the case of Escherichia coli only ampicillin and gentamicin resistance bacteria were detected. Our results show that antibiotics as well as resistant bacteria were eliminated by the modification of classical Fenton reaction with high efficiency. The modification of the Fenton reaction can decrease the process wages, environmental impact. Moreover, the degradation process was easily controlled, monitored and tuned.

  5. Catalytic activity of copper (II) oxide prepared via ultrasound assisted Fenton-like reaction.

    Science.gov (United States)

    Angı, Arzu; Sanlı, Deniz; Erkey, Can; Birer, Özgür

    2014-03-01

    Copper (II) oxide nanoparticles were synthesized in an ultrasound assisted Fenton-like aqueous reaction between copper (II) cations and hydrogen peroxide. The reactions were initiated with the degradation of hydrogen peroxide by ultrasound induced cavitations at 0 °C or 5 °C and subsequent generation of the OH radical. The radical was converted into hydroxide anion in Fenton-like reactions and copper hydroxides were readily converted to oxides without the need of post annealing or aging of the samples. The products were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and Brunauer-Emmett-Teller (BET) surface area analysis. Catalytic activity of the nanoparticles for the hydrogen peroxide assisted degradation of polycyclic aromatic hydrocarbons in the dark was tested by UV-visible spectroscopy with methylene blue as the model compound. The rate of the reaction was first order, however the rate constants changed after the initial hour. Initial rate constants as high as 0.030 min(-1) were associated with the high values of surface area, i.e. 70 m(2)/g. Annealing of the products at 150 °C under vacuum resulted in the decrease of the catalytic activity, underlying the significance of the cavitation induced surface defects in the catalytic process.

  6. Hydroxyl radical production by a heterogeneous Fenton reaction supported in insoluble tannin from bark of Pinus radiata.

    Science.gov (United States)

    Romero, Romina; Contreras, David; Segura, Cristina; Schwederski, Brigitte; Kaim, Wolfgang

    2016-09-02

    Fenton reactions driven by dihydroxybenzenes (DHBs) have been used for pollutant removal via advanced oxidation processes (AOPs), but such systems have the disadvantage of DHB release into the aqueous phase. In this work, insoluble tannins from bark can be used to drive Fenton reactions and as a heterogeneous support. This avoids the release of DHBs into the aqueous phase and can be used for AOPs. The production of ·OH was investigated using a spin-trapping electron paramagnetic resonance technique (5-dimethyl-1-pyrroline-N-oxide/·OH) in the first minute of the reaction and a high-performance liquid chromatography-fluorescence technique (coumarin/7-hydroxycoumarin) for 20 min. The ·OH yield achieved using insoluble tannins from Pinus radiata bark was higher than that achieved using catechin to drive the Fenton reaction. The Fenton-like system driven by insoluble tannins achieved 92.6 ± 0.3 % degradation of atrazine in 30 min. The degradation kinetics of atrazine was linearly correlated with ·OH production. The increased reactivity in ·OH production and insolubility of the ligand are promising for the development of a new technique for degradation of pollutants in wastewater using heterogeneous Fenton systems.

  7. 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.

  8. 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 activated carbon sites in the coal surface is used to explain the oxidation of the demineralized anthracite. ?? 1984.

  9. 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.

  10. Imaging the oxidation effects of the Fenton reaction on phospholipids at the interface between aqueous phase and thermotropic liquid crystals.

    Science.gov (United States)

    Zhang, Minmin; Jang, Chang-Hyun

    2015-08-01

    The lipid peroxidation process has attracted much attention because of the growing evidence of its involvement in the pathogenesis of age-related diseases. Herein, we report a simple, label-free method to study the oxidation of phospholipids by the Fenton reaction at the interface between an aqueous phase and immiscible liquid crystals (LCs). The different images produced by the orientation of 4-cyano-4'-pentylbiphenyl (5CB) corresponded to the presence or absence of oxidized 1,2-dioleoyl-sn-glycero-3-phospho-rac-(1-glycerol) sodium salt (DOPG). The oxidation effects of the Fenton reaction on DOPG were evaluated by monitoring the orientational response of liquid crystals upon contact with the oxidized DOPG solutions. DOPG was oxidized into chain-changed products containing hydroxy, carbonyl, or aldehyde groups, resulting in the rearrangement of the phospholipid layer. This induced the orientational transition of LCs from homeotropic to planar states; therefore, a dark to bright optical shift was observed. This shift was due to the Fenton reaction preventing DOPG to induce the orientational alignment of LCs at the aqueous/LC interface. We also used an ultraviolet spectrophotometer to confirm the effects of oxidation on phospholipids by the Fenton reaction. Using this simple method, a new approach for investigating phospholipid oxidation was established with high resolution and easy accessibility.

  11. Degradation of polyvinyl alcohol (PVA) by homogeneous and heterogeneous photocatalysis applied to the photochemically enhanced Fenton reaction.

    Science.gov (United States)

    Bossmann, S H; Oliveros, E; Göb, S; Kantor, M; Göppert, A; Lei, L; Yue, P L; Braun, A M

    2001-01-01

    The reaction mechanism of the oxidative degradation of polyvinyl alcohol (PVA) by the photochemically enhanced Fenton reaction was studied using a homogeneous (Fe2+(aq) + H2O2) and a heterogeneous reaction system (iron(III)-exchanged zeolite Y+ H2O2). In the homogeneous Fenton system, efficient degradation was observed in a batch reactor, equipped with a medium pressure mercury arc in a Pyrex envelope and employing 80% of the stoichiometric amount of H2O2 required for the total oxidation of PVA and a concentration ratio as low as I mole of iron(II) sulfate per 20 moles of PVA sub-units (C2H40). Model PVA polymers of three different molecular weights (15,000, 49,000 and 100,000 g mol(-1)) were found to follow identical degradation patterns. Strong experimental evidence supports the formation of supermacromolecules (MW: 1-5 x 10(6) g/mol) consisting of oxidized PVA and trapped iron(III) at an early reaction stage. Low molecular weight intermediates, such as oxalic acid, formic acid or formaldehyde were not found during PVA degradation in the homogeneous Fenton system, and we may deduce that the manifold of degradation reactions is mainly taking place within the super-macromolecules from which CO2 is directly released. However, in the heterogeneous Fenton system, the reaction behavior was found to be distinctly different: a decrease of the molecular weights of all three tested monodisperse PVA samples was observed by the broadening of the GPC-traces during irradiation, and oxalic acid was formed. The results lead to the mechanistic hypothesis that during the heterogeneous Fenton process, the cleavage of the PVA-chains may occur at random positions, the reactive centres being located inside the iron(III)-doped zeolite Y photocatalysts.

  12. 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.

  13. [Sensing of Cu²⁺ Based on Fenton Reaction and Unmodified Gold Nanoparticles].

    Science.gov (United States)

    Xing, Yun-peng; Liu, Chun; Zhou, Xiao-hong; Zhang, Li-pei; Shi, Han-chang

    2015-11-01

    Heavy metal pollution has received great attentions in recent years. The traditional methods for heavy metal detection rely on the expensive laboratory instruments and need time-consuming preparation steps; therefore, it is urgent to develop quick and highly sensitive new technologies for heavy metal detection. The colorimetric method based on the gold nanoparticles (AuNPs) features with simple operation, high sensitivity and low cost, therefore, enabling it widely concerned and used in the environmental monitoring, food safety and chemical and biological sensing fields. This work developed a simple, rapid and highly sensitive strategy based on the Fenton reaction and unmodified AuNPs for the detection of Cu²⁺ in water samples. The hydroxyl radical ( · OH) generated by the Fenton reaction between the Cu²⁺ and sodium ascorbate (SA) oxidized the single stranded DNA (ssDNA) attached on the AuNPs surface into variable sequence fragments. The cleavage of ssDNA induced the aggregation of AuNPs in a certain salt solution, therefore, resulting in the changes on the absorbance of solution. The assay conditions were optimized to be pH value of 7.9, 11 mg · L⁻¹ ssDNA, 8 mmol · L⁻¹ SA and 70 mmol · L⁻¹ NaCl. Results showed that the absorbance ratio values at the wavelengths of 700 and 525 nm (A₇₀₀/A₅₂₅) were linearly correlated with the Cu²⁺ concentrations. The linear detection range was 0.1-10.0 µmol · L⁻¹ with a detection limit of 24 nmol · L⁻¹ (3σ). Spiked recoveries ranged from 87%-120% in three sorts of water, including drinking water, tap water and lake water, which confirmed that the potentials of the proposed assay for Cu²⁺ detection in reality.

  14. Degradation of 2,4-dichlorophenol by combining photo-assisted Fenton reaction and biological treatment.

    Science.gov (United States)

    Al Momani, F; Sans, C; Contreras, S; Esplugas, S

    2006-06-01

    The photo-Fenton reaction effect on the biodegradability improvement of 100 mg/L solution of 2,4-dichlorophenol (DCP) has been investigated. Biochemical oxygen demand (BOD) at 5 and 21 days, BODn/ chemical oxygen demand (COD) and BODn/total organic carbon (TOC) ratios, average oxidation state, and inhibition on activated sludge were monitored. For 50 mg/L hydrogen peroxide and 10 mg/L iron(II) initial concentrations and 40 minutes of reaction time in the photo-Fenton process, the biodegradability of the pretreated solution, measured as BOD5/COD ratio, was improved from 0 for the original DCP solution up to 0.18 (BOD21/COD = 0.24). At that point, all DCP was eliminated from the solution. To study the effect of the pretreatment step, the biological oxidation of pretreated solutions was tested in two semicontinuous stirred tank reactors, one operated with activated sludge and one with biomass acclimated to phenol. Results showed that more than 80% TOC removal could be obtained by codigestion of the pretreated solution with municipal wastewater. Total organic carbon removals of approximately 60% were also obtained when the sole carbon source for the aerobic reactors was the pretreated solution. The hydraulic retention times used in the bioreactors were of the same order of magnitude as those used at domestic wastewater treatment plants (i.e., between 12 and 24 hours). Kinetic studies based on pseudo-first-order kinetics have also been carried out. Constants were found to be in range 0.67 to 1.7 L x g total volatiles suspended solids(-1) x h(-1).

  15. Model studies of the iron-catalysed Haber-Weiss cycle and the ascorbate-driven Fenton reaction.

    Science.gov (United States)

    Burkitt, M J; Gilbert, B C

    1990-01-01

    Complementary hydroxylation assays and stopped-flow e.s.r. techniques have been employed in the investigation of the effect of various iron chelators (of chemical, biological and clinical importance) on hydroxyl-radical generation via the Haber-Weiss cycle and the ascorbate-driven Fenton reaction. Chelators have been identified which selectively promote or inhibit various reactions involved in hydroxyl-radical generation (for example, NTA and EDTA promote all the reactions of both the Haber-Weiss cycle and the ascorbate-driven Fenton reaction, whereas DTPA and phytate inhibit the recycling of iron in these reactions). The biological chelators succinate and citrate are shown to be relatively poor catalysts of the Haber-Weiss cycle, whereas they are found to be effective catalysts of .OH generation in the ascorbate-driven Fenton reaction. It is also suggested that continuous redox-cycling reactions between iron, oxygen and ascorbate may represent an important mechanism of cell death in biological systems.

  16. Enhanced organic pollutants degradation and electricity production simultaneously via strengthening the radicals reaction in a novel Fenton-photocatalytic fuel cell system.

    Science.gov (United States)

    Zhao, Kai; Zeng, Qingyi; Bai, Jing; Li, Jinhua; Xia, Ligang; Chen, Shuai; Zhou, Baoxue

    2017-01-01

    An enhanced result in organic pollutants degradation and simultaneous electricity production has been achieved by establishing a novel Fenton-photocatalytic fuel cell (Fenton-PFC) system in which TiO2 nanotube arrays (TNA) was designed as a photoanode and ferrous ions were added. The proposed Fenton-PFC system can expand the radical reaction for organic pollutants degradation from the surface of electrodes to the whole solution system due to a continuous photoelectric Fenton reaction without continually adding any external voltage and ferrous ions. The cyclic reactions between ferrous ions (Fe(2+)/Fe(3+)) and radicals and related species (HO, HO2, O2(-) and H2O2 etc.) can be achieved at electrodes surface via a self-bias voltage yielded by the PFC. More importantly, the proposed Fenton-PFC system has hardly any sludge due to an effective radical reaction using a small amount of ferrous ions. The degradation rate of refractory organics, such as methyl orange, methylene blue, congo red and tetracycline, increased from 34.99%, 43.75%, 40.58% and 34.40% (the traditional PFC without Fe(2+)) to 97.34%, 95.36%, 93.23% and 73.80% (the Fenton-PFC within Fe(2+)) respectively after 60 min operation. Meanwhile, the electricity generation is up to 1.21-2.04 times larger than the traditional PFC. The proposed Fenton-PFC system provides a more economical and efficient way for energy recovery and wastewater treatment.

  17. Comparison of TiO2 photocatalysis, electrochemically assisted Fenton reaction and direct electrochemistry for simulation of phase I metabolism reactions of drugs.

    Science.gov (United States)

    Ruokolainen, Miina; Gul, Turan; Permentier, Hjalmar; Sikanen, Tiina; Kostiainen, Risto; Kotiaho, Tapio

    2016-02-15

    The feasibility of titanium dioxide (TiO2) photocatalysis, electrochemically assisted Fenton reaction (EC-Fenton) and direct electrochemical oxidation (EC) for simulation of phase I metabolism of drugs was studied by comparing the reaction products of buspirone, promazine, testosterone and 7-ethoxycoumarin with phase I metabolites of the same compounds produced in vitro by human liver microsomes (HLM). Reaction products were analysed by UHPLC-MS. TiO2 photocatalysis simulated the in vitro phase I metabolism in HLM more comprehensively than did EC-Fenton or EC. Even though TiO2 photocatalysis, EC-Fenton and EC do not allow comprehensive prediction of phase I metabolism, all three methods produce several important metabolites without the need for demanding purification steps to remove the biological matrix. Importantly, TiO2 photocatalysis produces aliphatic and aromatic hydroxylation products where direct EC fails. Furthermore, TiO2 photocatalysis is an extremely rapid, simple and inexpensive way to generate oxidation products in a clean matrix and the reaction can be simply initiated and quenched by switching the UV lamp on/off.

  18. 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.

  19. 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.

  20. Enzymatic degradation of endocrine-disrupting chemicals in aquatic plants and relations to biological Fenton reaction.

    Science.gov (United States)

    Reis, A R; Sakakibara, Y

    2012-01-01

    In order to evaluate the removal performance of trace phenolic endocrine-disrupting chemicals (EDCs) by aquatic plants, batch and continuous experiments were conducted using floating and submerged plants. The EDCs used in this study were bisphenol A, 2,4-dichlorophenol, 4-tert-octylphenol, pentachlorophenol, and nonylphenol. The feed concentration of each EDC was set at 100 μg/L. Continuous experiments showed that every EDC except pentachlorophenol was efficiently removed by different aquatic plants through the following reaction, catalyzed by peroxidases: EDCs+H(2)O(2)→Products+H(2)O(2). Peroxidases were able to remove phenolic EDCs in the presence of H(2)O(2) over a wide pH range (from 3 to 9). Histochemical localization of peroxidases showed that they were located in every part of the root cells, while highly concentrated zones were observed in the epidermis and in the vascular tissues. Although pentachlorophenol was not removed in the continuous treatment, it was rapidly removed by different aquatic plants when Fe(2+) was added, and this removal occurred simultaneously with the consumption of endogenous H(2)O(2). These results demonstrated the occurrence of a biological Fenton reaction and the importance of H(2)O(2) as a key endogenous substance in the treatment of EDCs and refractory toxic pollutants.

  1. Degradation of aniline by heterogeneous Fenton's reaction using a Ni-Fe oxalate complex catalyst.

    Science.gov (United States)

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

    2016-11-01

    A Ni-Fe oxalate complex catalyst was synthesized and characterized by means of Brunauer-Emmet-Teller (BET) method, scanning electron microscope (SEM) and X-ray photo-electron spectroscopy (XPS). The catalyst showed good catalytic activity for aniline degradation by heterogeneous Fenton's reaction, in which the synergetic index was 9.3. The effects of reaction temperature, catalyst dosage, hydrogen peroxide concentration and initial pH were investigated. Under the optimum conditions (T = 293 K, catalyst dosage = 0.2 g/L, H2O2 concentration = 4 mmol/L and initial pH = 5.4), 100% aniline could be removed within 35 min, and approximately 88% deamination efficiency was achieved in 60 min. The aniline degradation process followed the pseudo-first-order kinetic (k = 0.177 min(-1)) with activation energy (Ea) of 49.4 kJ mol(-1). Aniline could be removed in a broad initial pH (3-8) due to the excellent pH-tolerance property of the catalyst. The detected ammonium ion indicated that deamination occurred during aniline degradation. It was proposed that deamination synchronized with aniline removal, and aniline was attacked by free radicals to generate benzoquinonimine and phenol. This system is promising for the removal of aniline from water.

  2. 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

    2016-07-04

    The Photo-Fenton reaction is an advanced technology to eliminate organic pollutants in environmental chemistry. Moreover, the conversion rate of Fe(3+)/Fe(2+) 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 m(2 )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.

  3. 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.

  4. Plausible mechanisms of the fenton-like reactions, M = Fe(II) and Co(II), in the presence of RCO2(-) substrates: are OH(•) radicals formed in the process?

    Science.gov (United States)

    Kornweitz, Haya; Burg, Ariela; Meyerstein, Dan

    2015-05-01

    DFT calculations concerning the plausible mechanism of Fenton-like reactions catalyzed by Fe(II) and Co(II) cations in the presence of carboxylate ligands suggest that hydroxyl radicals are not formed in these reactions. This conclusion suggests that the commonly accepted mechanisms of Fenton-like reactions induced oxidative stress and advanced oxidation processes have to be reconsidered.

  5. Degradation of thiamethoxam by the synergetic effect between anodic oxidation and Fenton reactions.

    Science.gov (United States)

    Meijide, J; Gómez, J; Pazos, M; Sanromán, M A

    2016-12-05

    In this work, a comparative study using anodic oxidation, Fenton and electro-Fenton treatments was performed in order to determine the synergic effect for the removal of thiamethoxan. The results determined that electro-Fenton process showed high efficiency in comparison with Fenton or anodic oxidation. After that, this hybrid process was optimized and the influence of iron catalyst concentration and applied current intensity on the degradation and mineralization were evaluated. Degradation profiles were monitored by high performance liquid chromatography (HPLC) being satisfactorily described by pseudo-first order kinetic model. At the optimal experimental conditions (300mA and 0.2mM Fe(+2)), the complete degradation of thiamethoxam was achieved after 10min. On the other hand, mineralization of thiamethoxam was monitored by total organic carbon (TOC) decay reaching more than 92% of TOC removal after 8h. Furthermore, a plausible mineralization pathway for the thiamethoxam degradation was proposed based on the identification of by-products such as aromatic intermediates, carboxylic acids and inorganic ions released throughout electro-Fenton process.

  6. 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.

  7. Potential of modified iron-rich foundry waste for environmental applications: Fenton reaction and Cr(VI) reduction.

    Science.gov (United States)

    Oliveira, Patrícia E F; Oliveira, Leandro D; Ardisson, José D; Lago, Rochel M

    2011-10-30

    A magnetic fraction (15%) from a waste of foundry sand (WFS), composed of sand, carbon, bentonite clay and iron (10%) was modified by thermal treatment at 400, 600 and 800°C under inert atmosphere. Mössbauer analyses showed that the thermal treatment increased the amount of Fe(3)O(4) from 25 to 55% by reduction of Fe(2)O(3) and highly dispersed Fe(3+) by the carbon present in the waste. The Fe(3)O(4) caused a significant increase on the activity of two important reactions with application in environmental remediation: the Fenton oxidation of indigo carmine dye with H(2)O(2) and the reduction of Cr(VI) to Cr(III). The magnetic fraction of WFS was also mixed with hematite (Fe(2)O(3)) and thermally treated at 400, 600 and 800°C. This treatment produced large amounts of surface Fe(3)O(4) and increased substantially the rate of Fenton reaction as well as Cr(VI) reduction. This reactivity combined with the presence of carbon (an adsorbent for organic contaminants), bentonite clay (an adsorbent for metallic contaminants) and the granulometry/packing/hydrodynamic features make WFS a promising material for use in reactive permeable barriers.

  8. Reaction Kinetics of CoFeMg Oxide Nano Particles Fenton-Degraded Methylene Blue%CoFeMg氧化物纳米晶Fenton-降解亚甲基蓝的反应动力学

    Institute of Scientific and Technical Information of China (English)

    林松竹; 李婷婷; 贾若琨

    2014-01-01

    采用溶胶-凝胶法制备CoFeMg氧化物纳米晶,并用扫描电子显微镜(SEM)和 X 射线衍射(XRD)表征样品形貌,考察亚甲基蓝催化剂与 H 2 O 2的协同降解作用.采用稳态近似法研究氧化降解亚甲基蓝的动力学过程.结果表明:CoFeMg 氧化物纳米晶和 H2 O2组成的Fenton反应体系可有效降解亚甲基蓝,当催化剂和 H2 O2的加入量分别为0.8 g/L 和2 mmol/L,初始pH≈7.15时,亚甲基蓝的降解率为95%;与传统的Fenton反应体系相比,溶出铁的质量浓度降低为0.2 mg/L;Fenton 反应是羟基自由基(·OH)氧化降解有机物的过程,其反应可近似为二级动力学反应.%CoFeMg oxide nanocrystals were prepared with sol-gel method and characterized as a catalyst.SEM and XRD were used to characterize the catalyst,methylene blue was used to study the synergistic degradation of the catalyst and H2 O2 ,the dynamic process of oxidative degradation of methylene blue was studied by the steady-state approximation method.Results show that CoFeMg Fenton reaction system composed of CoFeMg oxide nanocrystals used as a heterogeneous Fenton-like catalyst and H2 O2 effectively degraded methylene blue.At pH≈7.15,a mass concentration of CoFeMg oxide nanocrystals of 0.8 g/L and concentration of H2 O2 of 2 mmol/L,the degradation rate of methylene blue was evaluated to be 95%.Compared with that of traditional Fenton reaction system,the amount of leaching of iron was decreased to 0.2 mg/L under similar conditions.The dynamics results show that Fenton reaction system shows a hydroxyl radicals (· OH )oxidation degradation process of methylene blue,and the reaction was considered as secondary dynamics.

  9. Insights into solar photo-Fenton reaction parameters in the oxidation of a sanitary landfill leachate at lab-scale.

    Science.gov (United States)

    Silva, Tânia F C V; Ferreira, Rui; Soares, Petrick A; Manenti, Diego R; Fonseca, Amélia; Saraiva, Isabel; Boaventura, Rui A R; Vilar, Vítor J P

    2015-12-01

    This work evaluates the effect of the main photo-Fenton (PF) reaction variables on the treatment of a sanitary landfill leachate collected at the outlet of a leachate treatment plant, which includes aerated lagooning followed by aerated activated sludge and a final coagulation-flocculation step. The PF experiments were performed in a lab-scale compound parabolic collector (CPC) photoreactor using artificial solar radiation. The photocatalytic reaction rate was determined while varying the total dissolved iron concentration (20-100 mg Fe(2+)/L), solution pH (2.0-3.6), operating temperature (10-50 °C), type of acid used for acidification (H2SO4, HCl and H2SO4 + HCl) and UV irradiance (22-68 W/m(2)). This work also tries to elucidate the role of ferric hydroxides, ferric sulphate and ferric chloride species, by taking advantage of ferric speciation diagrams, in the efficiency of the PF reaction when applied to leachate oxidation. The molar fraction of the most photoactive ferric species, FeOH(2+), was linearly correlated with the PF pseudo-first order kinetic constants obtained at different solution pH and temperature values. Ferric ion speciation diagrams also showed that the presence of high amounts of chloride ions negatively affected the PF reaction, due to the decrease of ferric ions solubility and scavenging of hydroxyl radicals for chlorine radical formation. The increment of the PF reaction rates with temperature was mainly associated with the increase of the molar fraction of FeOH(2+). The optimal parameters for the photo-Fenton reaction were: pH = 2.8 (acidification agent: H2SO4); T = 30 °C; [Fe(2+)] = 60 mg/L and UV irradiance = 44 WUV/m(2), achieving 72% mineralization after 25 kJUV/L of accumulated UV energy and 149 mM of H2O2 consumed.

  10. Central composite design for the optimization of removal of the azo dye, methyl orange, from waste water using fenton reaction

    Directory of Open Access Journals (Sweden)

    Azami Mahsa

    2012-01-01

    Full Text Available In this study the degradation of Methyl Orange, using Fenton reaction was studied and optimized using central composite design as a response surface methodology. The effects of various experimental parameters in this reaction were investigated using central composite design. 28 experiments, with 4 factors and 5 levels for each factor were designed. These factors (or variables were: initial concentration of Fe (II, initial concentration of H2O2, initial concentration of oxalate and the reaction time. A full-quadratic polynomial equation between the percentage of dye degradation (as a response and the studied parameters was established. After removing the non-significant variables from the model, response surface method was used to obtain the optimum conditions. The optimum ranges of variables were: 0.25 - 0.35 mM for initial concentration of Fe (II, 5-17 mM for initial concentration of H2O2, 4-9 mM for initial concentration of oxalate, and 50-80 min for the reaction time. Also the results of extra experiments showed that these optimized values can be used for real samples and yield to a high value for the response.

  11. Dissolved Organic Carbon Determination Using FIA and Photo-Fenton Reaction

    Directory of Open Access Journals (Sweden)

    Kondo Márcia M.

    2002-01-01

    Full Text Available The FIA-photo-Fenton system is based on the flow oxidation of the organic matter. A small amount of the sample containing H2O2 is injected into the acidic flow solution of Fe2+, which passes through a tubular PTFE reactor irradiated with UV light. The generated CO2 is quantified by a conductometric detector and is directly proportional to the dissolved organic carbon concentration in the sample. The optimization studies were performed using EDTA solutions. The average recovery of organic carbon was 83% with a relative standard deviation of 3.7% using a 1:5 molar ratio of Fe2+:H2O2, pH 2.0, 100 muL of sample injection and a liquid flow of 1 mL min-1. After optimization, the DOC concentration was quantified using 13 different organic compounds, where the average recovery was 90%. The rate of the analysis was in average 50 samples hour-1.

  12. 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.

  13. 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.

  14. Oxo iron(IV) as an oxidative active intermediate of p-chlorophenol in the Fenton reaction: a DFT study.

    Science.gov (United States)

    Mignon, Pierre; Pera-Titus, Marc; Chermette, Henry

    2012-03-21

    Debate continues over which active species plays the role of oxidative agent during the Fenton reaction-the HO˙ radical or oxo iron [Fe(IV)O](2+). In this context, the present study investigates the oxidation of p-chlorophenol by [Fe(IV)O(H(2)O)(5)](2+) using DFT calculations, within gas-phase and micro-solvated models, in order to explore the possible role of oxo iron as a reactant. The results show that the chlorine atom substitution of p-chlorophenol by oxo iron is a highly stabilising step (ΔH = -83 kcal mol(-1)) with a free energy barrier of 5.8 kcal mol(-1) in the micro-solvated model. This illustrates the high oxidising power of the [Fe(IV)O(H(2)O)(5)](2+) complex. On the other hand, the breaking of the Fe-O bond, leading to the formation of hydroquinone, is observed to be the rate-determining step of the reaction. The rather large free energy barrier corresponding to this bond cleavage amounts to 10.2 and 9.3 kcal mol(-1) in the gas-phase and micro-solvated models, respectively. Elsewhere, the lifetime of the HO˙ radical has previously been shown to be extremely small. These facts, combined with observations of oxo iron under certain experimental conditions, suggest that oxo iron is a highly plausible oxidative species of the reaction. In addition, a trigonal bipyramidal iron complex, coordinated either by hydroxyl groups and/or by water molecules, has been found in all described mechanisms. This structure appears to be a stable intermediate; and to our knowledge, it has not been characterised by previous studies.

  15. 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.

  16. Photoassisted Fenton degradation of polystyrene.

    Science.gov (United States)

    Feng, Hui-Min; Zheng, Jia-Chuan; Lei, Ngai-Yu; Yu, Lei; Kong, Karen Hoi-Kuan; Yu, Han-Qing; Lau, Tai-Chu; Lam, Michael H W

    2011-01-15

    Fenton and photoassisted Fenton degradation of ordinary hydrophobic cross-linked polystyrene microspheres and sulfonated polystyrene beads (DOWEX 50WX8) have been attempted. While the Fenton process was not able to degrade these polystyrene materials, photoassisted Fenton reaction (mediated by broad-band UV irradiation from a 250 W Hg(Xe) light source) was found to be efficient in mineralizing cross-linked sulfonated polystyrene materials. The optimal loadings of the Fe(III) catalyst and the H(2)O(2) oxidant for such a photoassisted Fenton degradation were found to be 42 μmol-Fe(III) and 14.1 mmol-H(2)O(2) per gram of the sulfonated polystyrene material. The initial pH for the degradation was set at pH 2.0. This photoassisted Fenton degradation process was also able to mineralize commonly encountered polystyrene wastes. After a simple sulfonation pretreatment, a mineralization efficiency of >99% (by net polymer weight) was achieved within 250 min. The mechanism of this advanced oxidative degradation process was investigated. Sulfonate groups introduced to the surface of the treated polystyrene polymer chains were capable of rapidly binding the cationic Fe(III) catalyst, probably via a cation-exchange mechanism. Such a sorption of the photoassisted Fenton catalyst was crucial to the heterogeneous degradation process.

  17. Degradation of the beta-blocker propranolol by electrochemical advanced oxidation processes based on Fenton's reaction chemistry using a boron-doped diamond anode

    Energy Technology Data Exchange (ETDEWEB)

    Isarain-Chavez, Eloy; Rodriguez, Rosa Maria; Garrido, Jose Antonio; Arias, Conchita; Centellas, Francesc; Cabot, Pere Lluis [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.ed [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)

    2010-12-15

    The electro-Fenton (EF) and photoelectro-Fenton (PEF) degradation of solutions of the beta-blocker propranolol hydrochloride with 0.5 mmol dm{sup -3} Fe{sup 2+} at pH 3.0 has been studied using a single cell with a boron-doped diamond (BDD) anode and an air diffusion cathode (ADE) for H{sub 2}O{sub 2} electrogeneration and a combined cell containing the above BDD/ADE pair coupled in parallel to a Pt/carbon felt (CF) cell. This naphthalene derivative can be mineralized by both methods with a BDD anode. Almost overall mineralization is attained for the PEF treatments, more rapidly with the combined system due to the generation of higher amounts of hydroxyl radical from Fenton's reaction by the continuous Fe{sup 2+} regeneration at the CF cathode, accelerating the oxidation of organics to Fe(III)-carboxylate complexes that are more quickly photolyzed by UVA light. The homologous EF processes are less potent giving partial mineralization. The effect of current density, pH and Fe{sup 2+} and drug concentrations on the oxidation power of PEF process in combined cell is examined. Propranolol decay follows a pseudo first-order reaction in most cases. Aromatic intermediates such as 1-naphthol and phthalic acid and generated carboxylic acids such as maleic, formic, oxalic and oxamic are detected and quantified by high-performance liquid chromatography. The chloride ions present in the starting solution are slowly oxidized at the BDD anode. In PEF treatments, all initial N of propranolol is completely transformed into inorganic ions, with predominance of NH{sub 4}{sup +} over NO{sub 3}{sup -} ion.

  18. Life detection experiments of the Viking Mission on Mars can be best interpreted with a Fenton oxidation reaction composed of H2O2 and Fe2+ and iron-catalysed decomposition of H2O2

    Science.gov (United States)

    Apak, Resat

    2008-10-01

    The findings of the life detection experiments carried out during the Viking mission to Mars were reinterpreted with a chemical hypothesis. The labelled release (LR), pyrolytic release (PR) and gas exchange (GEx) experiments were interpreted with Fenton chemistry. Oxygen and carbon dioxide evolution from Martian soil upon wetting and nutrient addition could be attributed to competition reactions between the Fenton-type oxidation of organic nutrients with the aqueous (hydrogen peroxide+Fe(II)) combination and the iron-catalysed decomposition of hydrogen peroxide. A substantial evolution of radioactive gas upon addition of labelled organic nutrient solution to soil, whereas the ceasing of this gas with a heat treated sample in the LR experiments, was attributed to Fenton oxidation and hydrogen peroxide thermal decomposition, respectively. The peculiar kinetics of LR and PR experiments that cannot be fully explained by other chemical or biochemical scenarios were easily explained with this new hypothesis, i.e. limitation of the Fenton reaction may arise from the depletion of reactants, the build-up of ferric hydroxide on soil and excessive scavenging by the organic nutrients of the generated hydroxyl radicals. Reabsorption or adsorption of evolved or introduced CO2 may involve the formation of carbonate compounds (e.g., magnesium carbonate and bicarbonate) on the surface of alkalinized soil as a result of the Fenton reaction. A critical evaluation of the recent biological hypothesis assuming the utilization of a hydrogen peroxide water intracellular fluid by putative organisms (Houtkooper & Schulze-Makuch 2007) is also made.

  19. Controlled reduction of red mud waste to produce active systems for environmental applications: heterogeneous Fenton reaction and reduction of Cr(VI).

    Science.gov (United States)

    Costa, Regina C C; Moura, Flávia C C; Oliveira, Patrícia E F; Magalhães, Fabiano; Ardisson, José D; Lago, Rochel M

    2010-02-01

    In this work, controlled reduction of red mud with H(2) was used to produce active systems for two different environmental applications, i.e. the heterogeneous Fenton reaction and the reduction of Cr(VI). Mössbauer, powder X-ray diffraction, thermal analyses and scanning electron microscopy analyses showed that at different temperatures, i.e. 300, 400, 500 and 600 degrees C, H(2) reduces red mud to different phases, mainly Fe(3)O(4), Fe(0)/Fe(3)O(4) and Fe(0). These Fe phases are dispersed on Al, Si and Ti oxides present in the red mud and show high reactivity towards two environmental applications, i.e. the heterogeneous Fenton reaction and the reduction of Cr(VI). Reduction with H(2) at 400 degrees C showed the best results for the oxidation of the model dye methylene blue with H(2)O(2) at neutral pH due to the presence of the composite Fe(0)/Fe(3)O(4). The reduced red mud at 500-600 degrees C produced Fe(0) highly active for the reduction of Cr(VI) in aqueous medium. Another feature of these red mud based system is that after deactivation due to extensive use they can be completely regenerated by simple treatment with H(2).

  20. Fenton reaction-mediated fluorescence quenching of N-acetyl-L-cysteine-protected gold nanoclusters: analytical applications of hydrogen peroxide, glucose, and catalase detection.

    Science.gov (United States)

    Deng, Hao-Hua; Wu, Gang-Wei; He, Dong; Peng, Hua-Ping; Liu, Ai-Lin; Xia, Xing-Hua; Chen, Wei

    2015-11-21

    Given the importance of hydrogen peroxide (H2O2) in many biological processes and its wide application in various industries, the demand for sensitive, accurate, and economical H2O2 sensors is high. In this study, we used Fenton reaction-stimulated fluorescence quenching of N-acetyl-L-cysteine-protected gold nanoclusters (NAC-AuNCs) as a reporter system for the determination of H2O2. After the experimental conditions were optimized, the sensing platform enabled the analysis of H2O2 with a limit of detection (LOD) as low as 0.027 μM. As the glucose oxidase cascade leads to the generation of H2O2 and catalase catalyzes the decomposition of H2O2, these two biocatalytic procedures can be probed by the Fenton reaction-mediated quenching of NAC-AuNCs. The LOD for glucose was found to be 0.18 μM, and the linear range was 0.39-27.22 μM. The LOD for catalase was 0.002 U mL(-1), and the linear range was 0.01-0.3 U mL(-1). Moreover, the proposed sensing methods were successfully applied for human serum glucose detection and the non-invasive determination of catalase activity in human saliva, demonstrating their great potential for practical applications.

  1. Degradation mechanism of Direct Pink 12B treated by iron-carbon micro-electrolysis and Fenton reaction.

    Science.gov (United States)

    Wang, Xiquan; Gong, Xiaokang; Zhang, Qiuxia; Du, Haijuan

    2013-12-01

    The Direct Pink 12B dye was treated by iron-carbon micro-electrolysis (ICME) and Fenton oxidation. The degradation pathway of Direct Pink 12B dye was inferred by ultraviolet visible (UV-Vis), infrared absorption spectrum (IR) and high performance liquid chromatography-mass spectrometry (HPLC-MS). The major reason of decolorization was that the conjugate structure was disrupted in the iron-carbon micro-electrolysis (ICME) process. However, the dye was not degraded completely because benzene rings and naphthalene rings were not broken. In the Fenton oxidation process, the azo bond groups surrounded by higher electron cloud density were first attacked by hydroxyl radicals to decolorize the dye molecule. Finally benzene rings and naphthalene rings were mineralized to H2O and CO2 under the oxidation of hydroxyl radicals.

  2. Use of iron and bio-oil wastes to produce highly dispersed Fe/C composites for the photo-Fenton reaction.

    Science.gov (United States)

    de Mendonça, Fernanda Gomes; Rosmaninho, Marcelo Gonçalves; da Fonseca, Philipe Xavier; Soares, Ricardo Reis; Ardisson, José Domingos; Tristão, Juliana Cristina; Lago, Rochel Montero

    2016-04-07

    This work describes the synthesis, characterization, and application of an active heterogeneous photo-Fenton system obtained from two different wastes, i.e., laterite (an iron mining waste) and the acid aqueous fraction (AAF) from bio-oil production. AAF with high acidity (ca. 3 molH+ L(-1)) and organic concentration (25 wt.%) obtained from biomass flash pyrolysis was used for the efficient extraction of Fe(3+) from laterite waste. After extraction, the mixture Fe(3+)/AAF was dried and treated at different temperatures, i.e., 500, 650, and 800 °C, to obtain Fe/C reactive composites. Mössbauer, XRD, TG, elemental analyses, and SEM/EDS showed the presence of highly disperse Fe oxide nanoparticles at 500 and 650 °C and Fe(0) particles in the material obtained at 800 °C with carbon contents varying from 74 to 80 %. The three composites were tested as heterogeneous catalysts in the photo-Fenton reaction for the oxidation of the model dye contaminant methylene blue, showing high activities at neutral pH.

  3. Biodegradability enhancement of a leachate after biological lagooning using a solar driven photo-Fenton reaction, and further combination with an activated sludge biological process, at pre-industrial scale.

    Science.gov (United States)

    Silva, Tânia F C V; Fonseca, Amélia; Saraiva, Isabel; Vilar, Vítor J P; Boaventura, Rui A R

    2013-06-15

    This work proposes an integrated leachate treatment strategy, combining a solar photo-Fenton reaction, to enhance the biodegradability of the leachate from an aerated lagoon, with an activated sludge process, under aerobic and anoxic conditions, to achieve COD target values and nitrogen content according to the legislation. The efficiency and performance of the photo-Fenton reaction, concerning a sludge removal step after acidification, defining the optimum phototreatment time to reach a biodegradable wastewater that can be further oxidized in a biological reactor and, activation sludge biological process, defining the nitrification and denitrification reaction rates, alkalinity balance and methanol dose necessary as external carbon source, was evaluated in the integrated system at a scale close to industrial. The pre-industrial plant presents a photocatalytic system with 39.52 m(2) of compound parabolic collectors (CPCs) and 2 m(3) recirculation tank and, an activated sludge biological reactor with 3 m(3) capacity. Leachate biodegradability enhancement by means of a solar driven photo-Fenton process was evaluated using direct biodegradability tests, as Zahn-Wellens method, and indirect measure according to average oxidation state (AOS), low molecular carboxylic acids content (fast biodegradable character) and humic substances (recalcitrant character) concentration. Due to high variability of leachate composition, UV absorbance on-line measurement was established as a useful parameter for photo-Fenton reaction control.

  4. Evaluation of the photo-fenton reaction in the decomposition of tick residues; Avaliacao da reacao foto-fenton na decomposicao de residuos de carrapaticida

    Energy Technology Data Exchange (ETDEWEB)

    Gromboni, Caio Fernando; Ferreira, Antonio Gilberto [Universidade Federal de Sao Carlos, SP (Brazil). Dept. de Quimica; Kamogawa, Marcos Yassuo [Sao Paulo Univ., Piracicaba, SP (Brazil). Escola Superior de Agricultura Luiz de Queiroz. Dept. de Ciencias Exatas; Nogueira, Ana Rita de Araujo [Embrapa Pecuaria Sudeste, Sao Carlos, SP (Brazil)]. E-mail: anarita@cppse.embrapa.br

    2007-03-15

    Experimental procedures based on factorial design and surface response methodology were applied to establish 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{sup -1} Fe{sup 2+} plus 1.9 mol L-1 H{sub 2}O{sub 2} 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. (author)

  5. 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.

  6. Mechanism of Photo-Fenton Degradation of Ethanol and PVA

    Institute of Scientific and Technical Information of China (English)

    雷乐成; 沈学优; 何锋

    2003-01-01

    Contrast degradation experiments between ethanol and polyvinyl alcohol (PVA) were conducted during H2O2, UV/H2O2, Fenton, and Photo-Fenton processes in this study. UV/VIS spectra showed: that complexes between Fe(Ⅲ) and organics were easily formed and degraded within reaction time. Compared with.the degradation of complex, hydroxyl radicals acted weakly in Fenton or Photo-Fenton process. Hydroxyl radicals involved in Photo-Fenton process were deemed to be generated from the split decomposition of H202, photolysis of Feaq3+, and degradation of hydrated Fe(IV)-complex but not traditional Fenton reaction. Experimental evidence to support this point was presented in this paper.

  7. 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)

  8. 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.

  9. 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.

  10. Demonstration of the heterolytic O-O bond cleavage of putative nonheme iron(II)-OOH(R) complexes for Fenton and enzymatic reactions.

    Science.gov (United States)

    Bang, Suhee; Park, Sora; Lee, Yong-Min; Hong, Seungwoo; Cho, Kyung-Bin; Nam, Wonwoo

    2014-07-21

    One-electron reduction of mononuclear nonheme iron(III) hydroperoxo (Fe(III)-OOH) and iron(III) alkylperoxo (Fe(III)-OOR) complexes by ferrocene (Fc) derivatives resulted in the formation of the corresponding iron(IV) oxo complexes. The conversion rates were dependent on the concentration and oxidation potentials of the electron donors, thus indicating that the reduction of the iron(III) (hydro/alkyl)peroxo complexes to their one-electron reduced iron(II) (hydro/alkyl)peroxo species is the rate-determining step, followed by the heterolytic O-O bond cleavage of the putative iron(II) (hydro/alkyl)peroxo species to give the iron(IV) oxo complexes. Product analysis supported the heterolytic O-O bond-cleavage mechanism. The present results provide the first example showing the one-electron reduction of iron(III) (hydro/alkyl)peroxo complexes and the heterolytic O-O bond cleavage of iron(II) (hydro/alkyl)peroxo species to form iron(IV) oxo intermediates which occur in nonheme iron enzymatic and Fenton reactions.

  11. RhB Adsorption Performance of Magnetic Adsorbent Fe3O4/RGO Composite and Its Regeneration through A Fenton-like Reaction

    Institute of Scientific and Technical Information of China (English)

    Yalin Qin; Mingce Long∗; Beihui Tan; Baoxue Zhou

    2014-01-01

    Adsorption is one of the most effective technologies in the treatment of colored matter containing wastewater. Graphene related composites display potential to be an effective adsorbent. However, the adsorp-tion mechanism and their regeneration approach are still demanding more efforts. An effective magnetically separable absorbent, Fe3O4 and reduced graphene oxide (RGO) composite has been prepared by an in situ coprecipitation and reduction method. According to the characterizations of TEM, XRD, XPS, Raman spectra and BET analyses, Fe3O4 nanoparticles in sizes of 10-20 nm are well dispersed over the RGO nanosheets, re-sulting in a highest specific area of 296.2 m2/g. The rhodamine B adsorption mechanism on the composites was investigated by the adsorption kinetics and isotherms. The isotherms are fitting better by Langmuir model, and the adsorption kinetic rates depend much on the chemical components of RGO. Compared to active carbon, the composite shows 3.7 times higher adsorption capacity and thirty times faster adsorption rates. Furthermore, with Fe3O4 nanoparticles as the in situ catalysts, the adsorption performance of composites can be restored by carrying out a Fenton-like reaction, which could be a promising regeneration way for the adsorbents in the organic pollutant removal of wastewater.

  12. Pyrite cinder as a cost-effective heterogeneous catalyst in heterogeneous Fenton reaction: decomposition of H(2)O(2) and degradation of Acid Red B.

    Science.gov (United States)

    Wu, Deli; Liu, Yanxia; Duan, Dong; Ma, Luming

    2014-01-01

    Pyrite cinder (PyC) was employed as a heterogeneous Fenton-like catalyst, and its catalytic activity was evaluated in view of the effects of catalyst dosage, pH and leaching metal ions. PyC showed significant reactivity, and the pseudo-first-order kinetic rate constant for decomposition of H(2)O(2) and degradation of Acid Red B (ARB) were 3.4 and 14.89 (10⁻³ min⁻¹) respectively when pH = 5. When 20 g/L PyC was added into 10 mM H(2)O(2) solution in neutral pH, H(2)O(2) could be completely degraded within 4 h, and more than 90% ARB was removed. Leaching metal ions from PyC were found to have little effect on decomposition of H(2)O(2) or on degradation of ARB. PyC still had high catalytic activity after five successive runs. The decomposition mechanism of H(2)O(2) was analyzed and the Haber-Weiss mechanism was employed in this paper. The electron spin resonance image showed •OH was produced and increased between 3 and 5 min in the PyC catalyzing H(2)O(2) reaction, which demonstrated that PyC had a durable ability to produce •OH.

  13. Degradação de corantes têxteis e remediação de resíduos de tingimento por processos Fenton, foto-Fenton e eletro-Fenton

    Directory of Open Access Journals (Sweden)

    Terezinha Salvador

    2012-01-01

    Full Text Available In this work the degradation of textile dyes were evaluated, using Fenton, photo-Fenton and electro-Fenton processes. Under optimized conditions Fenton and photo-Fenton processes showed high decolorization capacity of the model dyes. The electro-Fenton process was carried out in an undivided electrochemical reactor (1000 mL equipped with a carbon-felt cathode (253 cm² and a platinum gauze anode (6 cm². Under optimal conditions (J: 1.6 mA cm-2, Na2SO4: 0.075 mol L-1, pH: 3 H2O2 concentration of about 60 mg L-1 was observed. The addition of Fe2+ (15 mg L-1 induces Fenton reactions that permit almost total decolorization of textile dyes.

  14. 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.

  15. Comparison of Fenton, UV-Fenton and nano-Fe3O4 catalyzed UV-Fenton in degradation of phloroglucinol under neutral and alkaline conditions: Role of complexation of Fe3+ with hydroxyl group in phloroglucinol

    DEFF Research Database (Denmark)

    Wang, Yong; Lin, Xihuang; Shao, Zongze

    2017-01-01

    Phloroglucinol degradation at initial pH from 7.0 to 9.0 has been investigated in Fenton, UV-Fenton and nano-Fe3O4 catalyzed UV-Fenton (Hetero-Fenton). Within the reaction time given in this study (not more than 4 h), 150 mg·L−1 phloroglucinol was completely removed, while there was some...... difference in TOC removal efficiency: about 90% for UV-Fenton, nearly 60% for Fenton and Hetero-Fenton. Increasing initial pH from 7.0 to 9.0, there was an obvious decline in the degradation rate. The average values of H2O2 utilization efficiency were 0.65 ± 0.01 for Fenton, 0.66 ± 0.09 for UV...... important roles in Fenton degradation under neutral and alkaline pH. The result of effect of pollutant content showed phloroglucinol at lower concentrations of 20 and 50 mg·L−1 could still be completely removed by all Fenton-based systems at pH 7.0, however, in Fenton with 20 mg·L−1 phloroglucinol...

  16. Photo degradation of methyl orange an azo dye by advanced Fenton process using zero valent metallic iron: influence of various reaction parameters and its degradation mechanism.

    Science.gov (United States)

    Gomathi Devi, L; Girish Kumar, S; Mohan Reddy, K; Munikrishnappa, C

    2009-05-30

    Advanced Fenton process (AFP) using zero valent metallic iron (ZVMI) is studied as a potential technique to degrade the azo dye in the aqueous medium. The influence of various reaction parameters like effect of iron dosage, concentration of H(2)O(2)/ammonium per sulfate (APS), initial dye concentration, effect of pH and the influence of radical scavenger are studied and optimum conditions are reported. The degradation rate decreased at higher iron dosages and also at higher oxidant concentrations due to the surface precipitation which deactivates the iron surface. The rate constant for the processes Fe(0)/UV and Fe(0)/APS/UV is twice compared to their respective Fe(0)/dark and Fe(0)/APS/dark processes. The rate constant for Fe(0)/H(2)O(2)/UV process is four times higher than Fe(0)/H(2)O(2)/dark process. The increase in the efficiency of Fe(0)/UV process is attributed to the cleavage of stable iron complexes which produces Fe(2+) ions that participates in cyclic Fenton mechanism for the generation of hydroxyl radicals. The increase in the efficiency of Fe(0)/APS/UV or H(2)O(2) compared to dark process is due to continuous generation of hydroxyl radicals and also due to the frequent photo reduction of Fe(3+) ions to Fe(2+) ions. Though H(2)O(2) is a better oxidant than APS in all respects, but it is more susceptible to deactivation by hydroxyl radical scavengers. The decrease in the rate constant in the presence of hydroxyl radical scavenger is more for H(2)O(2) than APS. Iron powder retains its recycling efficiency better in the presence of H(2)O(2) than APS. The decrease in the degradation rate in the presence of APS as an oxidant is due to the fact that generation of free radicals on iron surface is slower compared to H(2)O(2). Also, the excess acidity provided by APS retards the degradation rate as excess H(+) ions acts as hydroxyl radical scavenger. The degradation of Methyl Orange (MO) using Fe(0) is an acid driven process shows higher efficiency at pH 3. The

  17. Cosmetic wastewater treatment using the Fenton, Photo-Fenton and H2O2/UV processes.

    Science.gov (United States)

    Marcinowski, Piotr P; Bogacki, Jan P; Naumczyk, Jeremi H

    2014-01-01

    Advanced Oxidation Processes (AOPs), such as the Fenton, photo-Fenton and H2O2/UV processes, have been investigated for the treatment of cosmetic wastewaters that were previously coagulated by FeCl3. The Photo-Fenton process at pH 3.0 with 1000/100 mg L(-1) H2O2/Fe(2+) was the most effective (74.0% Chemical Oxygen Demand (COD) removal). The Fenton process with 1200/500 mg L(-1) H2O2/Fe(2+) achieved a COD removal of 72.0%, and the H2O2/UV process achieved a COD removal of 47.0%. Spreading the H2O2 doses over time to obtain optimal conditions did not improve COD removal. The kinetics of the Fenton and photo-Fenton processes may be described by the following equation: d[COD]/dt = -a[COD] t(m) (t represents time and a and m are constants). The rate of COD removal by the H2O2/UV process may be described by a second-order reaction equation. Head Space, Solid-Phase MicroExtraction, Gas Chromatography and Mass Spectrometry (HS-SPME-GC-MS) were used to identify 48 substances in precoagulated wastewater. Among these substances, 26 were fragrances. Under optimal AOP conditions, over 99% of the identified substances were removed in 120 min.

  18. Study on condition of CaO2-based Fenton reaction by methylene blue spectrophotometric method%亚甲基蓝光度法研究基于CaO2的Fenton反应条件

    Institute of Scientific and Technical Information of China (English)

    刘娇; 孟范平; 王震宇; 刘启元

    2011-01-01

    The potential of calcium peroxide (CaO2) as a source of hydrogen peroxide (H2O2) in Fenton oxidation has been gradually taken note. In order to understand the characteristics of CaO2-based Fenton reactions, experiments were conducted using methylene blue spectrophotometric method to investigate effect of catalyst type, initial pH, CaO2 dose, molar ratio of catalyst to CaO2 (?Fe/?cao2 )? And phosphate buffer concentration on production of hydroxyl radicals (HO ? ). The results showed that under the experimental conditions Fez+ had better catalytic ability than Fe3+ and Cu2+. The optimal Fenton reaction conditions were; Fe2+ as catalyst, initial buffer pH = 4, CaO2 dose 1 mmol ? L"1 , wF,/?cao2 = 1/5, phosphate buffer concentration 40 mmol ? L"1. It was also indicated that the release of H2O2 and Fenton reaction were regulated by the dissolution process of CaO2 that could be a potential substitute for H2O2 in in-situ Fenton oxidations, because of decrease of H2O2 loss as well as negative impact of Fenton processes on the environment.%CaO2作为原位Fenton氧化修复中H2O2持续供源的作用逐渐受到关注.利用亚甲基蓝分光光度法评价了基于CaO2的Fenton反应中催化剂种类、初始pH值、CaO2用最、催化剂和CaO2比例、磷酸缓冲溶液浓度对羟基自由基(HO·)产率的影响.结果表明,采用Fe2作为催化剂,在pH值为4、CaO2用量为1 mmo1·L-1,催化剂CaO2摩尔比(nFe/nCaO2.)为1/5、磷酸缓冲溶液浓度为40 mmol·L-1时HO·产率较高,Fe2+催化作用最显著.CaO2溶解过程对H2O2的释放和Fenton反应起到一定调节作用,以CaO2取代H2O2可减少氧化剂的流失及其对环境产生的不利影响.

  19. 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.

  20. Use of Ligand-based Iron Complexes for Phenol Degradation by Fenton Modified Process

    OpenAIRE

    2013-01-01

    The efficiency of phenol degradation by the iron complexes ([Fe(TBMA)Cl33H2O] and [Fe(terpy)Cl2]) is compared with that of the Fenton reaction. The results show that although the Fenton reaction efficiently oxidizes phenol at low pHs, the Fenton modified reagents (iron complexes/H2O2) effectively oxidize phenol at neutral pH. Besides, the factorial designingstudy is performed by considering three independent variables: (i) [Fe] (A), (ii) pH (B), and (iii) [H2O2] (C). For the Fenton re...

  1. Stabilization of hydrogen peroxide using tartaric acids in Fenton and fenton-like oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Hyung Suk; Kim, Jeong-Jin; Kim, Young-Hun [Andong National University, Andong (Korea, Republic of)

    2016-03-15

    The stabilization of hydrogen peroxide is a key factor in the efficiency of a Fenton reaction. The stability of hydrogen peroxide was evaluated in a Fenton reaction and Fenton-like reactions in the presence of tartaric acid as a stabilizer. The interactions between ferrous or ferric iron and tartaric acid were observed through spectroscopic monitoring at variable pH around pKa{sub 1} and pKa{sub 2} of the stabilizer. Ferric iron had a strong interaction with the stabilizer, and the strong interaction was dominant above pKa{sub 2}. At a low pH, below pKa{sub 1}, the stabilizing effect was at its maximum and the prolonged life-time of hydrogen peroxide gave a higher efficiency to the oxidative degradation of nitrobenzene. In Fenton-like reactions with hematite, the acidic conditions caused dissolution of iron from an iron oxide, and an increase in iron species was the result. Tartaric acid showed a stabilizing effect on hydrogen peroxide in the Fentonlike system. The stabilization by tartaric acid might be due to an inhibition of catalytic activity of dissolved iron, and the stabilization strongly depends on the ionization state of the stabilizer.

  2. 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.

  3. Biological Sludge Stabilization; Fenton and Ozonation Processes

    Directory of Open Access Journals (Sweden)

    Miranzadeh M.B.1 PhD,

    2015-09-01

    Full Text Available Aims In biological wastewater treatment processes, a large amount of sludge is produced. Stabilization of sludge is essential before disposal because of the risks to human health and environment. Therefore, selecting an appropriate process for stabilization this sludge may efficiently decrease risks. The aim of this study was to examine the compound efficiency of the advanced Fenton and ozonation oxidation processes in stabilization of biological sludge. Instrument & Methods This experimental study was conducted on raw sludge taken from Kashan University of Medical Sciences’ Wastewater Treatment Plant in Iran during 2014. Fenton and ozonation oxidation processes were used for sludge stabilization. H2O2 and Fe2+ concentration, along with their mutual interaction, were measured using repeated measures model. Then the effects of pH and time reaction on reduction efficiency of volatile solids (VS were examined. Findings The maximum removal efficiencies in Fenton process at pH=3 and in ozonation process in pH=7 were obtained 85.1% and 92.9%, respectively. By increasing the reaction time from 30 to 90min, VS reduction efficiency in Fenton and ozonation processes increased and then reduced after 60min. The maximum reduction efficiencies of VS were obtained at 3000mg/l H2O2 concentration, So that the optimum ratio of Fe2+/H2O2 for sludge stabilization was 1000/3000mg/l with the efficiency of 91.5%. Conclusion Ozonation process efficiency in stabilizing biological wastewater sludge is higher than that of Fenton process.

  4. Comparison of classical fenton, nitrilotriacetic acid (NTA)-Fenton, UV-Fenton, UV photolysis of Fe-NTA, UV-NTA-Fenton, and UV-H2O2 for the degradation of cyclohexanoic acid.

    Science.gov (United States)

    Zhang, Ying; Klamerth, Nikolaus; Chelme-Ayala, Pamela; Gamal El-Din, Mohamed

    2017-05-01

    The treatment of a naphthenic acid model compound, cyclohexanoic acid, with classical Fenton, UV-H2O2, UV-Fenton, nitrilotriacetic acid (NTA)-Fenton, UV-NTA-Fenton, and UV photolysis of Fe-NTA processes at pHs 3 and 8 was investigated. At 1.47 mM H2O2, 0.089 mM Fe, and 0.18 mM NTA, the UV-NTA-Fenton process at pH 3 exhibited the highest H2O2 decomposition (100% in 25 min), CHA removal (100% in 12 min) with a rate constant of 0.27 ± 0.025 min(-1), and NTA degradation (100% in 6 min). Due to the formation of H2O2-Fe(III)NTA adduct, the total Fe concentration in the UV-NTA-Fenton system (0.063 mM at the end of the reaction) at pH 8 was much higher than that in the UV photolysis of Fe(III)NTA process (0.024 mM). The co-complexing effect of borate buffer helped to keep iron soluble; however, it imposed a negative influence on the CHA degradation in the UV-NTA-Fenton process (68% CHA removal in 60 min in the borate buffer compared to 92% in MilliQ water). The results demonstrated that the most efficient process for the CHA degradation under the experimental conditions was the UV-NTA-Fenton process at pH 3.

  5. 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.

  6. Mineralization of sulfamethizole in photo-Fenton and photo-Fenton-like systems.

    Science.gov (United States)

    Wu, C H; Wu, J T; Lin, Y H

    2016-01-01

    In this investigation, UV/H2O2, UV/H2O2/Fe(2+) (photo-Fenton) and UV/H2O2/Fe(3+) (photo-Fenton-like) systems were used to mineralize sulfamethizole (SFZ). The optimal doses of H2O2 (1-20 mM) in UV/H2O2 and iron (0.1-1 mM) in photo-Fenton and photo-Fenton-like systems were determined. Direct photolysis by UV irradiation and direct oxidation by added H2O2, Fe(2+) and Fe(3+) did not mineralize SFZ. The optimal dose of H2O2 was 10 mM in UV/H2O2 and that of iron (Fe(2+) or Fe(3+)) was 0.2 mM in both UV/H2O2/Fe(2+) and UV/H2O2/Fe(3+) systems. Under the best experimental conditions and after 60 min of reaction, the SFZ mineralization percentages in UV/H2O2, UV/H2O2/Fe(2+) and UV/H2O2/Fe(3+) systems were 16, 90 and 88%, respectively. The UV/H2O2/Fe(2+) and UV/H2O2/Fe(3+) systems effectively mineralized SFZ.

  7. 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.

  8. 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

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

    Science.gov (United States)

    Lucas, Marco S; Peres, José A; Amor, Carlos; Prieto-Rodríguez, Lucía; Maldonado, Manuel I; Malato, Sixto

    2012-07-30

    This work reports on pulp mill wastewater (PMW) tertiary treatment by Fenton (Fe(2+)/H(2)O(2)) and solar photo-Fenton (Fe(2+)/H(2)O(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 5mg Fe L(-1) reaches 90% of DOC mineralisation with 31kJ L(-1) of UV energy and 50mM of H(2)O(2). The initial non-biodegradability of PMW, as shown by respirometry assays and BOD(5)/COD ratio, can be changed after a solar photo-Fenton treatment. Experiments with 20 and 50mg Fe L(-1) revealed that solar photo-Fenton can reach the same DOC degradation (90%), however, consuming less H(2)O(2) and time. Diluting the initial organic load to 50% also diminishes the dosage of H(2)O(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.

  10. Fenton chemistry-based detemplation of an industrially relevant microcrystalline beta zeolite. Optimization and scaling-up studies

    NARCIS (Netherlands)

    Ortiz-Iniesta, Maria Jesus; Melian-Cabrera, Ignacio

    2015-01-01

    A mild template removal of microcrystalline beta zeolite, based on Fenton chemistry, was optimized. Fenton detemplation was studied in terms of applicability conditions window, reaction rate and scale up. TGA and CHN elemental analysis were used to evaluate the detemplation effectiveness, while 'CP,

  11. Degradation of sodium dodecyl sulphate in water using solar driven Fenton-like advanced oxidation processes

    Energy Technology Data Exchange (ETDEWEB)

    Bandala, Erick R. [Instituto Mexicano de Tecnologia del Agua, Paseo Cuauhnahuac 8532, Progreso Jiutepec, Morelos 62550 (Mexico)], E-mail: ebandala@tlaloc.imta.mx; Pelaez, Miguel A.; Salgado, Maria J. [Instituto Mexicano de Tecnologia del Agua, Paseo Cuauhnahuac 8532, Progreso Jiutepec, Morelos 62550 (Mexico); Torres, Luis [Instituto de Ingenieria, Universidad Nacional Autonoma de Mexico (UNAM) (Mexico)

    2008-03-01

    Synthetic wastewater samples containing a model surfactant were treated using two different Fenton-like advanced oxidation processes promoted by solar radiation; the photo-Fenton reaction and Co/PMS/UV processes. Comparison between the different experimental conditions was performed by means of the overall surfactant degradation achieved and by obtaining the initial rate in the first 15 min of reaction (IR{sub 15}). It was found that, for dark Fenton reaction, the maximum surfactant degradation achieved was 14% under low iron and oxidant concentration. Increasing Fenton reagents by one magnitude order, surfactant degradation achieved 63% in 60 min. The use of solar radiation improved the reaction rate by 17% under same conditions and an additional increase of 12.5% was obtained by adjusting initial pH to 2. IR{sub 15} values for dark and irradiated Fenton reactions were 0.143 and 0.154 mmol/min, respectively, for similar reaction conditions and this value increased to 0.189 mmol/min when initial pH was adjusted. The use of the Co/PMS system allow us to determine an increase in the degradation rate, for low reaction conditions (1 mM of transition metal; 4 mM oxidant) similar to those used in dark Fenton reaction. Surfactant degradation increased from 3%, for Fenton reaction, to 44.5% in the case of Co/PMS. When solar irradiation was included in the experiments, under same reaction conditions described earlier, surfactant degradation up to 64% was achieved. By increasing Co/PMS reagent concentration by almost 9 times under irradiated conditions, almost complete (>99%) surfactant degradation was reached in 5 min. Comparing IR{sub 15} values for Co/PMS and Co/PMS/UV, it allow us to observe that the use of solar radiation increased the degradation rate in one magnitude order when compared with dark experiments and further increase of reagent concentration increased reaction rate twice.

  12. Improved Understanding of Fenton-like Reactions for the In Situ Remediation of Contaminated Groundwater Including Treatment of Sorbed Contaminants and Destruction of DNAPLs

    Science.gov (United States)

    2006-04-29

    common reactions of hydroxyl radical are electrophilic substitution to aromatic compounds and addition to alkenes . Another class of hydroxyl radical...degree of halogenation, react rapidly with hydroxyl radical. Chlorinated alkenes , such as trichloroethylene (TCE) and perchloroethylene (PCE), also...nitrate to quench hydrated electrons, and chloroform to scavenge reductants. The CHP conditions included 1 mM Fe-NTA and 294 mM hydrogen peroxide. The

  13. 乙醇和PVA的光助Fenton降解机理%Mechanism of Photo-Fenton Degradation of Ethanol and PVA

    Institute of Scientific and Technical Information of China (English)

    雷乐成; 沈学优; 何锋

    2003-01-01

    Contrast degradation experiments between ethanol and polyvinyl alcohol (PVA) were conducted during H2O2, UV/H2O2, Fenton, and Photo-Fenton processes in this study. UV/VIS spectra showed. that complexes between Fe(Ⅲ) and organics were easily formed and degraded within reaction time. Compared with the degradation of complex, hydroxyl radicals acted weakly in Fenton or Photo-Fenton process. Hydroxyl radicals involved in Photo-Fenton process were deemed to be generated from the split decomposition of H2O2, photolysis of Fe3+/aq, and degradation of hydrated Fe(Ⅳ)-complex but not traditional Fenton reaction. Experimental evidence to support this point was presented in this paper.

  14. 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.

  15. Improvement in carbofuran degradation by different Fenton's reagent dosing processes.

    Science.gov (United States)

    Ma, Ying-Shih

    2011-11-01

    Attempts were made in this study to examine the efficiency of Fenton's reagent with different dosing processes and H(2)O(2) and Fe(2+) concentrations for the treatment of carbofuran wastewater. Carbofuran degradation, total organic carbon (TOC) removal and H(2)O(2) consumption were determined during the experiments. Increases in H(2)O(2) and Fe(2+) concentrations led to an increase in the degradation of carbofuran. Almost 100% of carbofuran could be degraded at pH 3, 120 mg L(-1) H(2)O(2), 24 mg L(-1) Fe(2+) and 30 minutes reaction time; removals of TOC were among 48.8%-53.3% under different dosing processes. A continuous dosing process was beneficial to improve the removal of TOC by Fenton's reagent. Rate constants of carbofuran degradation could be calculated by the first-order kinetics; increase in the Fenton's reagent generally increased the rate constants. Gas chromatography-mass spectrometry analysis found five degradation products by hydroxyl radicals attack. Thus, this study might offer an effective dosing way for carbofuran wastewater treatment by Fenton's reagent.

  16. Enhancement of Fenton and photo-Fenton processes at initial circumneutral pH for the degradation of the β-blocker metoprolol.

    Science.gov (United States)

    Romero, V; Acevedo, S; Marco, P; Giménez, J; Esplugas, S

    2016-01-01

    The need for acidification in the Fenton and photo-Fenton process is often outlined as one of its major drawbacks, thus in this work the acidification of the Metoprolol (MET) is avoided by the addition of resorcinol (RES), which is used to simulate model organic matter. The experiments were carried out at natural pH (6.2) with different Fe(2+) (1, 2.5, 5, and 10 mg/L) and H2O2 (25, 50, 125 and 150 mg/L) concentrations. The performance of MET and RES degradation was assessed along the reaction time. Working with the highest concentrations (5 and 10 mg/L of ferrous iron and 125 and 150 mg/L of H2O2) more than 90% of MET and RES removals were reached within 50 and 20 min of treatment, respectively, by Fenton process. However a low mineralization was achieved in both cases, likely, due to by-products accumulation. Regarding to photo-Fenton process, within 3 min with the highest iron and hydrogen peroxide concentrations, a complete MET degradation was obtained and 95% of RES conversion was achieved. Parameters such Total Organic Carbon, Chemical Oxygen Demand, and AOS were measured. Intermediates were identified and MET degradation path was proposed in the presence of resorcinol. Finally, a comparison between Fenton and photo-Fenton processes at acid pH and at initial circumneutral pH was discussed. The positive effect of RES on Fenton and photo-Fenton systems has been confirmed, allowing the work at circumneutral pH.

  17. 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.

  18. Factorial design analysis for COD removal from landfill leachate by photoassisted Fered-Fenton process.

    Science.gov (United States)

    Wu, Xiaogang; Zhang, Hui; Li, Yanli; Zhang, Daobin; Li, Xianwang

    2014-01-01

    The Fered-Fenton process has been shown to be an effective method for leachate treatment, but it still faces problems of inadequate regeneration of ferrous ion. However, the use of the photoassisted Fered-Fenton process could overcome this difficulty and improve the efficiency of chemical oxygen demand (COD) removal since photoassisted Fered-Fenton process induces the production of hydroxyl radicals from the regeneration of ferrous ions and the reaction of hydrogen peroxide with UV light. As there are so many operating parameters in photoassisted Fered-Fenton process, it is necessary to develop a mathematical model in order to produce the most economical process. In the present study, a factorial design was carried out to evaluate leachate treatment by photoassisted Fered-Fenton process. The influence of the following variables: H₂O₂ concentration, Fe(2+) concentration, current density, and initial pH in the photoassisted Fered-Fenton process was investigated by measuring COD removal efficiencies after 60-min reaction. The relationship between COD removal and the most significant independent variables was established by means of an experimental design. The H₂O₂ concentration, Fe(2+) concentration, initial pH, and the interaction effect between current density and initial pH were all significant factors. The factorial design models were derived based on the COD removal efficiency results and the models fit the data well.

  19. Biological Fenton's oxidation of pentachlorophenol by aquatic plants.

    Science.gov (United States)

    Reis, Andre Rodrigues dos; Kyuma, Yukako; Sakakibara, Yutaka

    2013-12-01

    This study proposes a new treatment method to decompose persistent chemicals such as pentachlorophenol (PCP) in water, utilizing hydrogen peroxide present in aquatic plants to proceed the biological Fenton reaction. PCP was not effectively removed by aquatic plants. However, by adding 2.8 mM of Fe(2+), there was a rapid removal of PCP while at the same time consumption of endogenous hydrogen peroxide occurred. It was observed the increase of chloride ions formation in water-confirming the complete degradation of PCP. These results demonstrated that PCP was oxidized through a biological Fenton reaction, and hydrogen peroxide in aquatic plants was a key endogenous substance in treatment of refractory toxic pollutants.

  20. 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.

  1. [Characteristics of nitrobenzene containing wastewater catalytic oxidation degradation by Fenton reagent].

    Science.gov (United States)

    Wei, C; Chen, C; Wang, G; Ren, Y; Wu, C; Wu, H

    2001-09-01

    Through the alteration of the concentration of catalyst and oxidant, the rulers and dynamics of nitrobenzene oxidized by Fenton reagent in different concentrations were studied. The correlativity of the reaction time and relatively remain nitrobenzene was analyzed by the unitary linear regress equation. The result of the analysis proves that the coefficient was over the critical constant. The oxidation of nitrobenzene by Fenton reagent was in conformity with first-order dynamics model and the reaction rate constant was got at the same time. The idea, using the complex of Fe as the catalyst replacing Fe2+ in the Fenton Reaction, not only got a higher reaction velocity and efficiency, but also had a distinct exclusive to the degradation of nitrobenzene. The remove velocity of nitrobenzene was improved from 17.48 mg/(L.min) to 71.22 mg/(L.min), the remove rate in 5 minutes was from 9.74% to 91.79%. The nonhomogeneous catalyst made by the artificial zeolite with Fe-complex adsorbed had the same catalyzing behavior. In addition, ultraviolet radiation can also improves the Fenton reaction to some degree. These research works could demonstrate the good application potentiality of Fenton reagent in treating wastewater.

  2. 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. 

  3. Oxidation of 2,6-dimethylaniline by the Fenton, electro-Fenton and photoelectro-Fenton processes.

    Science.gov (United States)

    Ting, Wang-Ping; Huang, Yao-Hui; Lu, Ming-Chun

    2011-01-01

    Fenton technologies for wastewater treatment have demonstrated their effectiveness in eliminating toxic compounds. This study examines how hydrogen peroxide concentration and ultraviolet (UV) light affects oxidation processes. However, total mineralization through these Fenton technologies is expensive compared with biological technologies. Therefore, partial chemical oxidation of toxic wastewaters with Fenton processes followed by biological units may increase the application range of Fenton technologies. Using 2,6-dimethylaniline (2,6-DMA) as the target compound, this study also investigates oxidation intermediates and their biodegradable efficiencies after treatment by Fenton, electro-Fenton and photoelectron-Fenton processes. Analytical results show that the UV light-promoting efficiency, r(PE-F)/r(E-F), was 2.02, 2.55 and 2.67 with initial hydrogen peroxide concentrations of 15, 20 and 25 mM, respectively. We conclude that UV irradiation promoted 2,6-DMA degradation significantly. The same tendency was observed for biochemical oxygen demand/total organic carbon (BOD(5)/TOC) ratios for each process, meaning that 2,6-DMA can be successfully detoxified using the electro-Fenton and photoelectro-Fenton processes. Some organic intermediates aminobenzene, nitrobenzene, 2,6-dimethylphenol, phenol and oxalic acid--were detected in different oxidation processes.

  4. Experimental study on the pre-treatment of flotation wastewater by UV/Fenton oxidation-coagulation process%UV/Fenton -混凝法对浮选废水预处理研究

    Institute of Scientific and Technical Information of China (English)

    吕春玲; 王莹; 刘强

    2015-01-01

    试验考察了UV/Fenton法和CCG788/UV/Fenton法对浮选废水进行预氧化后,废水中COD去除效果的影响因素。其结果表明:UV/Fenton 法处理效果明显优于普通 Fenton 法,而CCG788的加入提高了 UV/Fenton 体系对紫外光的利用率,不仅氧化效果更好,还可以促进UV/Fenton氧化反应的进行,缩短反应时间。在前述试验结果基础上,对CCG788/UV/Fenton法处理后的浮选废水投加CCG158进行了二次氧化,COD去除率可提高到87%,并缩短了总反应时长。%Pre-oxidation of flotation wastewater by UV/Fenton and CCG 788/UV/Fenton process was exploredin terms of the influence factors on COD removal.The experiment results show that UV/Fenton oxidation process is much more effective for the pre-treatment of flotation wastewater than Fenton oxidation process.In addition,the introduction of CCG788 into UV/Fenton system improves the utilization of ultraviolet ray( UV) and removal rates of COD,as well as promotes oxidation reaction and shortens the reaction time.Furthermore,the total removal rate of COD can reach 87 %by secondary oxidation of CCG788/UV/Fenton flotation wastewater with CCG158,and the reaction time is shortened.

  5. 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.

  6. Studies on Catalytic Degradation of Phenol Wastewater by Fenton and UV/Fenton%Fenton和UV-Fenton催化降解苯酚废水研究

    Institute of Scientific and Technical Information of China (English)

    赵丽红; 孙洪军

    2015-01-01

    The efficiency of Fenton and UV -Fenton is examined using phenol as a model compound .A batch study is con-ducted to optimize parameters like pH ,hydrogen peroxide concentration and ferrous ion concentration .At optimum condi-tions ,two processes are compared for the degradation of phenol .The degradation and mineralisation efficiency can be in-creased in UV-Fenton processes compared to conventional Fenton process and the maximum mineralising efficiency for phe-nol with UV-Fenton and Fenton processes is 98% and 40% respectively .In Fenton process ,carboxylic acids like acetic acid and oxalic acid can be formed as end products during the degradation of phenol ,while in UV -Fenton process ,both these ions are identified during the early stages of phenol degradation and oxidized almost completely at 120mins of the reac-tion time .In UV-Fenton process ,concentration of Fe2+ is 0 .4 mmol/L and that is 0 .8 mmol/L in conventional Fenton process .%研究Fenton和UV-Fenton两种工艺对苯酚的降解效率。分批研究优化pH值、温度、H2 O2浓度和Fe2+浓度。在最优条件下,比较了两种工艺降解苯酚的效果。结果表明,UV -Fenton工艺比传统的Fenton工艺增加了降解和矿化效率,最大的矿化效率分别是98%和40%。在Fenton工艺中,苯酚的最终产物是羧酸如醋酸和草酸,而在UV-Fenton工艺中,这些离子在苯酚降解的早期阶段形成,在120 min的反应时间内几乎完全氧化。在UV-Fenton工艺中Fe2+浓度为0.4 mmol/L ,而Fenton工艺中Fe2+浓度为0.8 mmol/L。

  7. Design of an electro-Fenton system with a novel sandwich film cathode for wastewater treatment.

    Science.gov (United States)

    Fan, Yan; Ai, Zhihui; Zhang, Lizhi

    2010-04-15

    In this study, we demonstrate an electro-Fenton (E-Fenton) system constructed with a novel sandwich film cathode (SFC). For the fabrication of SFC, Fe(2+)-chitosan (Fe-CHI) was first deposited on foam nickel (Fe-CHI/Ni). Then two pieces of Fe-CHI/Ni was used to fasten one piece of activated carbon fiber (ACF) to obtain a Fe-CHI/Ni|ACF|Fe-CHI/Ni sandwich film cathode. We interestingly found that this SFC based E-Fenton system could effectively degrade rodamine B with in situ generating both hydrogen peroxide and iron ions. Its degradation efficiency was significantly higher than those of the E-Fenton systems constructed with composite cathodes of carbon nanotubes with Fe@Fe(2)O(3) core-shell nanowires or Cu(2)O nanocubes reported in our previous studies. Hydrogen peroxide electrogenerated through the reduction of O(2) adsorbed on the sandwich film cathode and the iron ions produced by the leakage from Fe(2+)-chitosan film during the E-Fenton reaction were, respectively, monitored, providing clues to understand the high efficiency of this novel SFC based E-Fenton system. More importantly, this low-cost sandwich film cathode was very stable and could be reused without catalytic activity decrease, suggesting its potential application in the wastewater treatment.

  8. Degradation of carbofuran in aqueous solution by ultrasound and Fenton processes: Effect of system parameters and kinetic study.

    Science.gov (United States)

    Ma, Ying-Shih; Sung, Chi-Fanga; Lin, Jih-Gaw

    2010-06-15

    To establish an efficient oxidation process for carbofuran degradation, the effects of some operating parameters such as dosages of H(2)O(2), Fe(2+) and initial carbofuran concentrations were observed during carbofuran degradation by the ultrasound process, Fenton process and a combined ultrasound/Fenton process. The degradation kinetics of carbofuran was also examined based on the experimental data. The results show that more than 99% of the carbofuran was degraded by the ultrasound/Fenton process within short reaction time periods. Increased dosages of H(2)O(2) and Fe(2+) enhanced the degradation of carbofuran in the ultrasound and Fenton oxidation processes, but initial carbofuran concentrations decreased carbofuran degradation in both the Fenton and ultrasound/Fenton processes. The degradation kinetics of carbofuran by the three oxidation processes was found to be in accordance with first-order reaction kinetics. The results provide fundamental information about the treatment of carbofuran wastewater and/or other pesticides by the ultrasound/Fenton oxidation process.

  9. Fenton reagent and titanium dioxide nanoparticles as antifungal agents to control leaf spot of sugar beet under field conditions

    Directory of Open Access Journals (Sweden)

    Hamza Amany

    2016-07-01

    Full Text Available In this study, foliar sprays of Fenton solutions (Fenton reaction, Fenton-like reaction and Fenton complex, titanium dioxide (TiO2 and the recommended fungicide (chlorothalonil were estimated in the control of sugar beet leaf spot caused by Cercospora beticola under field conditions in two growing seasons. In addition, the impacts of these treatments on some crop characters (leaf dry weight, root fresh weight, soluble solid content, sucrose content and purity of sugar were examined. Biochemical and histological changes in the livers and kidneys of treated rats compared to an untreated control were utilized to assess the toxicity of the examined curative agents. Overall, chlorothalonil and Fenton complex were the most effective treatments for disease suppression in both tested seasons followed by Fenton-like reagent, Fenton’s reagent and TiO2, respectively. Growth and yield characters of treated sugar beet significantly increased in comparison to an untreated control. There were mild or no (biochemical and histological changes in the livers and kidneys of treated rats compared to the control. Fenton solutions and TiO2 may offer a new alternative for leaf spot control in sugar beet.

  10. 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.

  11. Scaling-up parameters for site restoration process using surfactant-enhanced soil washing coupled with wastewater treatment by Fenton and Fenton-like processes.

    Science.gov (United States)

    Bandala, Erick R; Cossio, Horacio; Sánchez-Lopez, Adriana D; Córdova, Felipe; Peralta-Herández, Juan M; Torres, Luis G

    2013-01-01

    Estimation of scaling-up parameters for a site restoration process using a surfactant-enhanced soil washing (SESW) process followed by the application of advanced oxidation processes (Fenton and photo-Fenton) was performed. For the SESW, different parameters were varied and the soil washing efficiency for pesticide (2,4-D) removal assessed. The resulting wastewater was treated using the Fenton reaction in the absence and presence of ultraviolet (UV) radiation for pesticide removal. Results showed that agitation speed of 1550 rpm was preferable for the best pesticide removal from contaminated soil. It was possible to wash contaminated soils with different soil concentrations; however the power drawn was higher as the soil concentration increased. Complete removal of the pesticide and the remaining surfactant was achieved using different reaction conditions. The best degradation conditions were for the photo-Fenton process using [Fe(II)] = 0.3 mM; [H2O2] = 4.0 mM where complete 2,4-D and sodium dodecylsulfate (SDS) removal was observed after 8 and 10 minutes of reaction, respectively. Further increase in the hydrogen peroxide or iron salt concentration did not show any improvement in the reaction rate. Kinetic parameters, i.e. reaction rate constant and scaling-up parameters, were determined. It was shown that, by coupling both processes (SESW and AOPs), it is possible the restoration of contaminated sites.

  12. Treatment of Wastewater Containing RDX by Fenton's Reagent

    Institute of Scientific and Technical Information of China (English)

    XU Hang; ZHANG Dong-xiang; XU Wen-guo

    2008-01-01

    Fenton's reagent was employed to treat the wastewater containing RDX. The effects of FeSO4 concentration, H2O2 concentration, pH value, reaction time, temperature and initial COD of wastewater on residual COD of wastewater were investigated. The results show that the optimum FeSO4 concentration and pH are 700mg/L and 2.5, respectively, and the residual COD of wastewater decreases with the rise in H2O2 concentration, but increases with the rise in temperature. After Fenton's reagent treatment, the initial COD of less than 874 mg/L wastewater can meet effluent standard. Under conditions of 100 mg/L H2O2, 437 mg/L initial COD and 15 ℃ temperature, the lowest residual COD is obtained at 83.80 mg/L in 5 min.

  13. 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.

  14. The sonochemical decolourisation of textile azo dye Orange II: effects of Fenton type reagents and UV light.

    Science.gov (United States)

    Dükkancı, Meral; Vinatoru, Mircea; Mason, Timothy J

    2014-03-01

    The removal of Orange II (O-II) from aqueous solution under irradiation at 850 kHz has been studied. The effects of both homogeneous (with FeSO4/H2O2), and heterogeneous (Fe containing ZSM-5 zeolite/H2O2) Fenton type reagents are reported together with the effect of UV irradiation in combination with ultrasound both alone and with homogeneous Fenton-type reagent. Degrees of decolourisation of 6.5% and 28.9% were observed using UV radiation and ultrasound, respectively, whereas under the simultaneous irradiation of ultrasound and UV light, the decolourisation degree reached 47.8%, indicating a synergetic effect of ultrasound and UV light. The decolourisation was increased with the addition of Fenton's reagent with an optimal Fenton molar reagent ratio, Fe(2+):H2O2 of 1:50. In the combined process of ultrasound and UV light with the homogeneous Fenton system 80.8% decolourisation could be achieved after 2h indicating that UV improves this type of Orange II degradation. The degree of decolourisation obtained using the heterogeneous sono-Fenton system (Fe containing ZSM-5 zeolite catalysts+H2O2+ultrasound) were consistently lower than the traditional homogeneous ultrasound Fenton system. This can be attributed to the greater difficulty of the reaction between Fe ions and hydrogen peroxide. In all cases the Orange II ultrasonic decolourisation was found to follow first order kinetics.

  15. Fenton degradation of Cartap hydrochloride: identification of the main intermediates and the degradation pathway.

    Science.gov (United States)

    Tian, Kaixun; Ming, Cuixiang; Dai, Youzhi; Honore Ake, Kouassi Marius

    2015-01-01

    The advanced oxidation of Cartap hydrochloride (Cartap) promoted by the Fenton system in an aqueous medium was investigated. Based on total organic carbon, chemical oxygen demand and high-performance liquid chromatography, the oxidation of Cartap is quite efficient by the Fenton system. Its long chain is easily destroyed, but the reaction does not proceed to complete mineralization. Ion chromatography detection indicated the formation of acetic acid, propionic acid, formic acid, nitrous acid and sulfuric acid in the reaction mixtures. Further evidence of nitrogen monoxide and sulfur dioxide formation was obtained by using a flue gas analyzer. Monitoring by gas chromatograph-mass spectrometer demonstrated the formation of oxalic acid, ethanol, carbon dioxide, and L-alanine ethylamide. Based on these experimental results, plausible degradation pathways for Cartap mineralization in an aqueous medium by the Fenton system are proposed.

  16. 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)

  17. Roles of iron species and pH optimization on sewage sludge conditioning with Fenton's reagent and lime.

    Science.gov (United States)

    Yu, Wenbo; Yang, Jiakuan; Shi, Yafei; Song, Jian; Shi, Yao; Xiao, Jun; Li, Chao; Xu, Xinyu; He, Shu; Liang, Sha; Wu, Xu; Hu, Jingping

    2016-05-15

    Conditioning sewage sludge with Fenton's reagent could effectively improve its dewaterability. However, drawbacks of conditioning with Fenton's reagent are requirement of acidic conditions to prevent iron precipitation and subsequent neutralization with alkaline additive to obtain the pH of the filtrate close to neutrality. In this study, roles of pH were thoroughly investigated in the acidification pretreatment, Fenton reaction, and the final filtrate after conditioning. Through the response surface methodology (RSM), the optimal dosages of H2SO4, Fe(2+), H2O2, and lime acted as a neutralizer were found to be 0 (no acidification), 47.9, 34.3 and 43.2 mg/g DS (dry solids). With those optimal doses, water content of the dewatered sludge cakes could be reduced to 55.8 ± 0.6 wt%, and pH of the final filtrate was 6.6 ± 0.2. Fenton conditioning without initial acidification can simplify the conditioning process and reduce the usage of lime. The Fe(3+) content in the sludge cakes showed a close correlation with the dewaterability of conditioned sludge, i.e., the water content of sludge cakes, SRF (specific resistance to filtration), CST (capillary suction time), bound water content, and specific surface area. It indicated that the coagulation by Fe(3+) species in Fenton reaction could play an important role, compared to traditional Fenton oxidation effect on sludge conditioning. Thus, a two-step mechanism of Fenton oxidation and Fe(III) coagulation was proposed in sewage sludge conditioning. The mechanisms include the following: (1) extracellular polymeric substances (EPS) were firstly degraded into dissolved organics by Fenton oxidation; (2) bound water was converted to free water due to degradation of EPS; (3) the sludge particles were disintegrated into small ones by oxidation; (4) Fe(3+) generated from Fenton reaction acted as a coagulant to agglomerate smaller sludge particles into larger dense particles with less bond water; (5) finally, the dewatered

  18. Bacterial-fungal interactions enhance power generation in microbial fuel cells and drive dye decolourisation by an ex situ and in situ electro-Fenton process.

    Science.gov (United States)

    Fernández de Dios, María Ángeles; del Campo, Araceli González; Fernández, Francisco Jesús; Rodrigo, Manuel; Pazos, Marta; Sanromán, María Ángeles

    2013-11-01

    In this work, the potential for sustainable energy production from wastes has been exploited using a combination fungus-bacterium in microbial fuel cell (MFC) and electro-Fenton technology. The fungus Trametes versicolor was grown with Shewanella oneidensis so that the bacterium would use the networks of the fungus to transport the electrons to the anode. This system generated stable electricity that was enhanced when the electro-Fenton reactions occurred in the cathode chamber. This configuration reached a stable voltage of approximately 1000 mV. Thus, the dual benefits of the in situ-designed MFC electro-Fenton, the simultaneous dye decolourisation and the electricity generation, were demonstrated. Moreover, the generated power was effectively used to drive an ex situ electro-Fenton process in batch and continuous mode. This newly developed MFC fungus-bacterium with an in situ electro-Fenton system can ensure a high power output and a continuous degradation of organic pollutants.

  19. 类Fenton氧化-絮凝耦合处理活性艳红K-2BP的研究%Study of coupled oxidation and flocculation process in treating reactive brilliant red K-2BP by a Fenton-like reaction

    Institute of Scientific and Technical Information of China (English)

    范先媛; 刘红; 余薇; 朱小丽

    2011-01-01

    以H2O2为氧化剂、聚硅硫酸亚铁(PFSSⅡ)为催化絮凝剂,两者耦合形成类Fenton试剂氧化-絮凝处理活性艳红K-2BP废水.当PFSSⅡ的铁硅摩尔比为1∶3,H2O2和PFSSⅡ的投加量分别为10 mg/L和15 mg/L(以Fe2+计)时,活性艳红的脱色率可达到98%以上,且氧化反应速率符合三级反应速率方程.与传统Fenton相比,类Fenton试剂氧化絮凝处理后的絮体粒度及沉降性能具有明显的优势.通过耦合反应前后污染物和产物的紫外和红外吸收光谱,对活性艳红的降解机理和PFSSⅡ的絮凝机理进行了探讨.%Using H202 as the oxidant and poly-silicon ferrous sulfate (PFSS Ⅱ ) as the catalytic flocculant,H2O2 and PFSS Ⅱ were coupled to form Fenton-like reagent for treating reactive brilliant red K-2BP wastewater.When the n(Fe): n(Si) of PFSS Ⅱ was 1: 3, and the dosages of H2O2 and PFSS Ⅱ were 10 mg/L and 15 mg/L,respectively, the decoloration rate of reactive brilliant red was above 98% , and the oxidation rate fit for the thirdorder equation of reaction rate. Compared with traditional Fenton reagent, there were obvious advantages in the size and sedimentation performance of the flocs that produced by Fenton-like. The degradation mechanism of reactive brilliant red and the flocculation mechanism of PFSS Ⅱ were analyzed by UV-vis adsorption spectrum and FTIR spectrum.

  20. Treatment of oilfield fracturing wastewater by a sequential combination of flocculation, Fenton oxidation and SBR process.

    Science.gov (United States)

    Yang, Jian; Hong, Liang; Liu, Yan-Hong; Guo, Jian-Wei; Lin, Li-Fei

    2014-01-01

    In this study, a combined process was developed that included flocculation, Fenton oxidation and sequencing batch reactor (SBR) to treat oilfield fracturing wastewater (FW). Flocculation and Fenton oxidation were applied to reduce chemical oxygen demand (COD) organic load and to enhance biodegradability, respectively. For flocculation, the optimum conditions were: polymeric aluminium chloride dosage, 40 mg/L; polyacrylamide dosage, 4 mg/L; dilution ratio, 1:2 and stirring time, 30 min. For Fenton oxidation, a total reaction time of 60 min, a H₂O₂dosage of 2 m mol/L, with a [H₂O₂]/[FeSO₄] ratio of 2 were selected to achieve optimum oxidation. Under these optimum flocculation and Fenton oxidation conditions, the COD removal efficiency was found to be 76.6%. Following pretreatment with flocculation and Fenton oxidation, the FW was further remediated using a SBR. Results show that COD was reduced to 92 mg/L, and the overall water quality of the final effluent could meet the class I national wastewater discharge standard of petrochemical industry of China.

  1. Fenton-enhanced {gamma}-radiolysis of cyanuric acid

    Energy Technology Data Exchange (ETDEWEB)

    Varghese, Rani [School of Chemical Sciences, Mahatma Gandhi University, Kottayam 686560, Kerala (India); Aravind, Usha K. [School of Chemical Sciences, Mahatma Gandhi University, Kottayam 686560, Kerala (India); Aravindakumar, Charuvila T. [School of Chemical Sciences, Mahatma Gandhi University, Kottayam 686560, Kerala (India)]. E-mail: CT-Aravindakumar@rocketmail.com

    2007-04-02

    Degradation of cyanuric acid (OOOT), a stable end product of oxidative decomposition of atrazine, is investigated in a combined field of gamma radiolysis and fenton reaction. The reaction of hydroxyl radical ({center_dot}OH) at pH 6 was carried out by irradiating N{sub 2}O saturated aqueous solutions containing OOOT (1 x 10{sup -3} mol dm{sup -3}), and this resulted only a marginal degradation (20%). However, when the same reaction was carried out in the presence of varying concentrations of ferrous sulfate ((5-10) x 10{sup -5} mol dm{sup -3}), the decay of OOOT has been enhanced to more than 80%. This decay followed a first order kinetics. Nearly similar effects were observed with another triazine derivative, 2,4-dioxohexahydro-1,3,5-triazine (DHT). Two major reaction mechanisms are proposed for the enhanced decay of OOOT. The formation of unstable hydroxyl radical adducts from the reaction of {center_dot}OH which is the result of gamma radiolysis and the Fenton reaction (resulting from the reaction of the added Fe(II) and of the H{sub 2}O{sub 2} from the radiolysis of water), is proposed as the first mechanism. The second mechanism, which is likely the major contributor to degradation, is proposed as the reaction of a nucleophilic adduct, Fe(II)OOH, which could directly react with the electron deficient triazine ring. It is highlighted that such degradation reactions must be explored for the complete degradation of the byproducts of the oxidative decomposition of atrazine.

  2. Degradation of trans-ferulic acid in acidic aqueous medium by anodic oxidation, electro-Fenton and photoelectro-Fenton.

    Science.gov (United States)

    Flores, Nelly; Sirés, Ignasi; Garrido, José Antonio; Centellas, Francesc; Rodríguez, Rosa María; Cabot, Pere Lluís; Brillas, Enric

    2016-12-01

    Solutions of pH 3.0 containing trans-ferulic acid, a phenolic compound in olive oil mill wastewater, have been comparatively degraded by anodic oxidation with electrogenerated H2O2 (AO-H2O2), electro-Fenton (EF) and photoelectro-Fenton (PEF). Trials were performed with a BDD/air-diffusion cell, where oxidizing OH was produced from water discharge at the BDD anode and/or in the solution bulk from Fenton's reaction between cathodically generated H2O2 and added catalytic Fe(2+). The substrate was very slowly removed by AO-H2O2, whereas it was very rapidly abated by EF and PEF, at similar rate in both cases, due to its fast reaction with OH in the bulk. The AO-H2O2 process yielded a slightly lower mineralization than EF, which promoted the accumulation of barely oxidizable products like Fe(III) complexes. In contrast, the fast photolysis of these latter species under irradiation with UVA light in PEF led to an almost total mineralization with 98% total organic carbon decay. The effect of current density and substrate concentration on the performance of all treatments was examined. Several solar PEF (SPEF) trials showed its viability for the treatment of wastewater containing trans-ferulic acid at larger scale. Four primary aromatic products were identified by GC-MS analysis of electrolyzed solutions, and final carboxylic acids like fumaric, acetic and oxalic were detected by ion-exclusion HPLC. A reaction sequence for trans-ferulic acid mineralization involving all the detected products is finally proposed.

  3. Application of solar photo-Fenton toward toxicity removal and textile wastewater reuse.

    Science.gov (United States)

    Starling, Maria Clara V M; Dos Santos, Paulo Henrique Rodrigues; de Souza, Felipe Antônio Ribeiro; Oliveira, Sílvia Corrêa; Leão, Mônica M D; Amorim, Camila C

    2016-08-27

    Solar photo-Fenton represents an innovative and low-cost option for the treatment of recalcitrant industrial wastewater, such as the textile wastewater. Textile wastewater usually shows high acute toxic and variability and may be composed of many different chemical compounds. This study aimed at optimizing and validating solar photo-Fenton treatment of textile wastewater in a semi-pilot compound parabolic collector (CPC) for toxicity removal and wastewater reclamation. In addition, treated wastewater reuse feasibility was investigated through pilot tests. Experimental design performed in this study indicated optimum condition for solar photo-Fenton reaction (20 mg L(-1) of Fe(2+) and 500 mg L(-1) of H2O2; pH 2.8), which achieved 96 % removal of dissolved organic carbon (DOC) and 99 % absorbance removal. A toxicity peak was detected during treatment, suggesting that highly toxic transformation products were formed during reaction. Toxic intermediates were properly removed during solar photo-Fenton (SPF) treatment along with the generation of oxalic acid as an ultimate product of degradation and COS increase. Different samples of real textile wastewater were treated in order to validate optimized treatment condition with regard to wastewater variability. Results showed median organic carbon removal near 90 %. Finally, reuse of treated textile wastewater in both dyeing and washing stages of production was successful. These results confirm that solar photo-Fenton, as a single treatment, enables wastewater reclamation in the textile industry. Graphical abstract Solar photo-Fenton as a revolutionary treatment technology for "closing-the-loop" in the textile industry.

  4. UV/Fenton及Fenton体系降解愈创木酚的机理探讨%Discussion on the Mechanism of Guaiacol Degradation by UV/Fenton and Fenton Processes

    Institute of Scientific and Technical Information of China (English)

    刘芳; 杨艳明; 王昶

    2011-01-01

    This paper selected guaiacol, one model compound of lignin, as the target compound to study the degradation of guaiacol by UV/ Fenton and Fenton processes. With the help of guaiacol UV-visible spectrum changes, comparison of guaiacol removal rate and mineralization rate, the degradation mechanism of guaiacol by UV/Fenton and Fenton processes treatment was discussed. The experimental results showed that UV/Fenton and Fenton processes are not simply free radical reactions. Fe2+ and H202 can generate high iron complexes. The guaiacol is degraded with the electron transfer of complexes.%选择木素类模型物愈创木酚作为目标化合物,对UV/Fenton和Fenton体系降解愈创木酚的过程进行研究,结合愈创木酚紫外-可见光谱的变化、愈创木酚去除率和矿化率的比较,对UV/Fenton和Fenton体系降解愈创木酚的机理加以探讨.实验发现,UV/Fenton和Fenton体系不只是单纯的自由基反应,Fe2+还可以和H2 02生成高价铁配合物,通过配合物的电子转移使愈刨木酚得到氧化.

  5. Photo-Fenton and Fenton Oxidation of Recalcitrant Wastewater from the Wooden Floor Industry.

    Science.gov (United States)

    Hansson, Henrik; Kaczala, Fabio; Marques, Marcia; Hogland, William

    2015-06-01

    There is a need for development of on-site wastewater treatment technologies suitable to "dry-process" industries, such as the wooden floor sector. Due to the nature of their activities, these industries generate low volumes of highly polluted and recalcitrant wastewaters due to washing and cleaning surfaces and machinery. Advanced oxidation processes such as Fenton and photo-Fenton are potentially feasible options for the treatment of wastewaters with not easily biodegradable pollutants. The wastewater from a wooden floor industry with initial COD value of 4956 mg/L and TOC value of 2730 mg/L was treated with Fenton (Fe/H2O2) and photo-Fenton (Fe/H2O2/UV) applying a 2-level full-factorial experimental design. The highest removals of COD and TOC (79% and 62% respectively) were achieved when photo-Fenton was applied. In conclusion, Fenton and photo-Fenton are promising treatment options for these highly recalcitrant wastewaters, photo-Fenton being a more promising option according to the results.

  6. 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

  7. Study of solar photo-Fenton system applied to removal of phenol from water.

    Science.gov (United States)

    Freire, Layla F A; da Fonseca, Fabiana Valéria; Yokoyama, Lidia; Teixeira, Luiz Alberto Cesar

    2014-01-01

    This study evaluated the use of a Fenton's reaction in a falling film solar reactor (FFR), as a possible advanced oxidation process for the mineralization of the organic compound phenol in water. Preliminary tests were carried out to evaluate phenol degradation by photolysis and to select the optimal residence time in which to carry out the process using a solar photo-Fenton system. The variables studied were the initial phenol concentration (100 to 300 mg L(-1)), the [Phenol]:[H2O2] mass ratio (1.0 to 2.0) and the [H2O2]/[Fe2+] molar ratio (5 to 10). Phenol degradation of 99% and chemical oxygen demand (COD) reduction of 97% were obtained under the following reaction conditions: phenol concentration=200 mg L(-1), mass ratio [Phenol]:[H2O2]=1.5 and molar ratio [H2O2]/[Fe2+]=7.5. Overall mineralization was achieved using the solar photo-Fenton process to destroy phenol and COD. The solar photo-Fenton process using a FFR appears to be a viable method for removing phenols in wastewaters on an industrial scale.

  8. A Novel Mechanism for Halogenated Quinone- Mediated and Metal-Independent Organic Fenton-Like Reaction%不依赖于过渡金属离子的卤代醌介导的新型有机类Fenton反应机理

    Institute of Scientific and Technical Information of China (English)

    朱本占; 任福荣; 夏海英; 邵杰

    2012-01-01

    卤代醌是许多卤芳香持久有机污染物的致癌代谢产物和饮用水消毒副产物.羟基自由基(OH)被公认为生物系统中最具活性的活性氧物种,能导致生物体内DNA等生物大分子的氧化损伤.目前,最被广泛接受的OH产生机理是过渡金属离子催化的Fenton反应.综合采用电子自旋共振二级自旋捕获和其他分析方法,发现四氯苯醌和其它卤代醌皆可通过不依赖于过渡金属离子的途径,显著促进氢过氧化物(H2O2或有机氢过氧化物)的分解而产生OH或烷氧自由基,并首次检测到一种新型的、以碳为中心的醌自由基.基于以上研究,提出一类不依赖于过渡金属离子的卤代醌介导的新型有机类Fenton反应机理.%Halogenated quinones are a class of carcinogenic metabolites of many halogenated persistent organic pollutants and new chlorination disinfection byproducts in drinking water. The hydroxyl radical ("OH) has been considered to be one of the most reactive oxygen species produced in biological systems. It has been shown that 'OH can cause oxidative damage to DNA and other macromolecuies. One of the most widely accepted mechanisms for OH production is through the transition metal-catalyzed Fenton reaction. Through the complementary application of electron spin resonance (ESR) secondary spin-trapping and other analytical methods, we found that tetrachloro-1,4-benzoquinone (TCBQ) and other halogenated quinones could markedly enhance the decomposition of hydroperoxides (H2O2 and organic hydroperoxides) and formation of "OH and alkoxyl radicals independent of transition metal ions. A novel carbon-centered quinone ketoxy radical was also detected and identified for the first time. Based on these data, we proposed a novel mechanism for metal-independent and halogenated quinone-mediated organic Fenton-like reaction.

  9. Landfill Leachates Treatment by /UV, /, Modified Fenton, and Modified Photo-Fenton Methods

    Directory of Open Access Journals (Sweden)

    Jeremi Naumczyk

    2012-01-01

    Full Text Available Advanced oxidation processes (AOPs such as H2O2/UV, O3/H2O2, modified Fenton, and modified photo-Fenton processes have been investigated in terms of the treatment of landfill leachate with ratio of BOD5/COD in the range of 0.22 to 0.24. The modification of Fenton and photo-Fenton processes consisted in the inclusion of precipitation and separation of humic substances at pH 3. Due to the precipitation, the value of COD decreased by 39% and BOD5 by 7.1%. The modification of the processes allowed us to improve the efficiency and to decrease the doses of reagents necessary to continue the process. Modified photo-Fenton process proved to be the most effective (92.7% COD removal of all processes investigated. Additionally, modified-Fenton process was much more effective than the other two processes when compared up to 120 min, while after longer times it gave the least satisfactory results. After 30 min of modified-Fenton process BOD5/COD ratio increased to 0.43. The parameter referred to as “efficiency of oxidants” was used to estimate the efficiency of all the processes—its value varied from 178 to 239%. Various substances including phthalates, hydrocarbons, silanes, and siloxanes were identified in raw and treated leachate.

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

    Energy Technology Data Exchange (ETDEWEB)

    Hermosilla, Daphne, E-mail: dhermosilla@quim.ucm.es [Departamento de Ingenieria Quimica, Facultad de Ciencias Quimicas, Universidad Complutense de Madrid, Ciudad Universitaria s/n, 28040 Madrid (Spain); Cortijo, Manuel [U.D. Operaciones Basicas, Departamento de Ingenieria Forestal, E.T.S.I. Montes, Universidad Politecnica de Madrid, Avda. Ramiro de Maeztu s/n, 28040 Madrid (Spain); Huang, Chin Pao [Department of Civil and Environmental Engineering, 352C DuPont Hall, University of Delaware, Newark, DE 19716 (United States)

    2009-05-15

    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 Fe{sup 2+} 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. Electro-fenton and photoelectro-fenton degradation of sulfanilic acid using a boron-doped diamond anode and an air diffusion cathode.

    Science.gov (United States)

    El-Ghenymy, Abdellatif; Garrido, José Antonio; Centellas, Francesc; Arias, Conchita; Cabot, Pere Lluís; Rodríguez, Rosa María; Brillas, Enric

    2012-04-01

    The mineralization of sulfanilic acid has been studied by electro-Fenton (EF) and photoelectro-Fenton (PEF) reaction with UVA light using an undivided electrochemical cell with a boron-doped diamond (BDD) anode and an air diffusion cathode able to generate H(2)O(2). Organics were then oxidized by hydroxyl radicals formed at the anode surface from water oxidation and in the bulk from Fenton's reaction between generated H(2)O(2) and added Fe(2+). The UVA irradiation in PEF enhanced the production of hydroxyl radicals in the bulk, accelerating the removal of organics and photodecomposed intermediates like Fe(III)-carboxylate complexes. Partial decontamination of 1.39 mM sulfanilic acid solutions was achieved by EF until 100 mA cm(-2) at optimum conditions of 0.4 mM Fe(2+) and pH 3.0. The increase in current density and substrate content led to an almost total mineralization. In contrast, the PEF process was more powerful, yielding almost complete mineralization in less electrolysis time under comparable conditions. The kinetics for sulfanilic acid decay always followed a pseudo-first-order reaction. Hydroquinone and p-benzoquinone were detected as aromatic intermediates, whereas acetic, maleic, formic, oxalic, and oxamic acids were identified as generated carboxylic acids. NH(4)(+) ion was preferentially released in both treatments, along with NO(3)(-) ion in smaller proportion.

  12. Treating leachate with advanced oxidation: applying Fenton's reagent; Oxidaciones avanzadas para el tratamiento de lixiviado: aplicacion del Reactivo de Fenton

    Energy Technology Data Exchange (ETDEWEB)

    Maranonn Ruiz, I.; Sancho Seuma, L.

    2003-07-01

    The present study investigates the removal of refractory organics by Advanced Oxidation Process: Fenton's Reaction. A batch test protocol was designed to study the oxidation and coagulation in Fenton Reaction. The batch tests were conducted to determine the optimum conditions for the plant operation such as pH, H{sub 2}O{sub 2} dosage, FeSO{sub 4} dosage and contact time. It was found that the highest removal efficiencies of COD were with the oxidation at acid pH around 3 and the coagulation at basic pH around 8, few minutes of treatment time, the initial concentrations of H{sub 2}O{sub 2} were in the range 68-1550 mg/l and the different dosages of FeSO{sub 4} were in the range 487-3038 mg/l. They were added in determinate proportions to get the highest efficiency of producing OH, DBO{sub 5}/DQO ratio was decreased from 0,3 to 0,1. Therefore Fenton's reaction process is a very effective means for a pretreatment or tertiary treatment of biological methods. (Author) 20 refs.

  13. A combined process of adsorption and Fenton-like oxidation for furfural removal using zero-valent iron residue.

    Science.gov (United States)

    Li, Furong; Bao, Jianguo; Zhang, Tian C; Lei, Yutian

    2015-01-01

    In this study, the feasibility of using a combined adsorption and Fenton-like oxidation process (with zero-valent iron (ZVI) residue from heat wraps as an absorbent and catalyst) to remove furfural in the solution was evaluated. The influencing parameters (e.g. pH, H2O2 concentration, initial furfural concentration) and the reusability of ZVI residue (to replace the iron powder) were estimated. The ZVI residue was found to have much better adsorption effect on furfural at pH 2.0 compared with pH 6.7. For Fenton-like reaction alone with ZVI residue, the highest furfural removal of 97.5% was observed at the concentration of 0.176 mol/L H2O2, and all of the samples had >80% removal efficiency at different initial furfural concentrations of 2, 10, 20, 30 and 40 mmol/L. However, with a combined adsorption and Fenton-like oxidation, the removal efficiency of furfural was nearly 100% for all treatments. The ZVI residue used for furfural removal was much better than that of iron powder in the Fenton-like reaction at a seven-cycle experiment. This study suggests the combined process of adsorption and Fenton-like oxidation using ZVI residue is effective for the treatment of furfural in the liquid.

  14. Treatment of sugarcane vinasse by combination of coagulation/flocculation and Fenton's oxidation.

    Science.gov (United States)

    Guerreiro, Lígia F; Rodrigues, Carmen S D; Duda, Rose M; de Oliveira, Roberto A; Boaventura, Rui A R; Madeira, Luis M

    2016-10-01

    The efficiency of individual and integrated processes applied to organic matter reduction and biodegradability improvement of a biodigested sugarcane vinasse wastewater was assessed. Strategies considered were Fenton's oxidation (Strategy 1), coagulation/flocculation (Strategy 2) and the combination of both processes (coagulation/flocculation followed by Fenton's reaction) - Strategy 3. It was found that Fenton's oxidation per se allowed reducing the organic matter, increasing the wastewater biodegradability and a non-toxic effluent was generated; however the cost of treatment was very high (86.6 R$/m(3) - 21.2 €/m(3)). Under optimized conditions, coagulation/flocculation provided a slight increase in effluent's biodegradability, toxicity towards Vibrio fischeri was also eliminated and moderate removals of total organic carbon - TOC - (30.5%), biological oxygen demand - BOD5 - (27.9%) and chemical oxygen demand - COD - (43.6%) were achieved; however, the operating costs are much smaller. The use of dissolved iron resulting from coagulation/flocculation (270 mg/L) as catalyst in the second stage - Fenton's oxidation - was shown to be an innovative and economically attractive strategy. Under optimal conditions overall removals of 51.6% for TOC, 45.7% for BOD5 and 69.2% for COD were achieved, and a biodegradable (BOD5:COD ratio = 0.54) and non-toxic effluent was obtained. In order to increase the efficiency of the process but using less hydrogen peroxide, the Fenton's oxidation was performed by gradually adding the oxidant. This procedure allowed to obtain the highest organic matter removal efficiency (as compared with the addition of all hydrogen peroxide at the beginning of the reaction). This way it was possible to minimize the reagent consumption and, consequently, reduce the treatment cost.

  15. Degradation of carbofuran-contaminated water by the Fenton process.

    Science.gov (United States)

    Ma, Ying-Shih; Kumar, Mathava; Lin, Jih-Gaw

    2009-07-15

    In this study, the Fenton process was applied for the degradation of carbofuran from aqueous system. Batch experiments were conducted at two different carbofuran concentrations i.e., 10 and 50 mg/L, and at pH 3. Batch experiments at each carbofuran concentration were designed by central composite design (CCD) with two independent variables i.e. Fe2+ and H2O2. Experimental results indicate that more than 90% of carbofuran removal was observed within 5 mins of Fenton reaction at 5 mg/L of Fe2+ concentration and 100 mg/L of H202 concentration. Increases in Fe2+ and/or H2O2 concentrations beyond 5 and 100 mg/L, respectively produced 100% carbofuran removal. Based on the experimental observations, the optimal Fe2+ and H2O2 dosages required for 10 mg/L of aqueous carbofuran removal were estimated as 7.4 and 143 mg/L, respectively. During this study, three carbofuran intermediates such as 7-benzofuranol,2,3,-dihydro-2,2-dimethyl, 7-hydroxy-2,2-dimethyl-benzofuran-3-one and 1,4-Benzene-di-carboxaldehyde were identified using GC/MS analyses.

  16. Fenton-like application to pretreated cheese whey wastewater.

    Science.gov (United States)

    Prazeres, Ana R; Carvalho, Fátima; Rivas, Javier

    2013-11-15

    Cheese whey wastewater has been treated by the Fenton-like oxidation system after being pre-processed through a coagulation - flocculation stage with FeCl3 or alternatively, through a sedimentation step with Ca(OH)2 plus aerobic digestion. In the first case, Fenton-like oxidation is capable of reducing the initial COD (chemical oxygen demand) to 80% of the initial value, 20% of COD shows recalcitrance to chemical oxidation regardless of the operating conditions used. In the second case, the oxidation system is capable of removing almost the total COD present in the pretreated effluent. Given the lower values of initial COD, complete COD conversion is achieved at short reaction times within minutes depending on the initial reagent concentration. Removal of Fe(III) from the oxidation treatment can be achieved by Ca(OH)2 addition. Sedimentation pH significantly affects the observed settling rate. Hence, neutral conditions lead to better results than slightly acidic pHs.

  17. 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.

  18. Enhancing biodegradability of priority substances (pesticides) by solar photo-Fenton.

    Science.gov (United States)

    Lapertot, Milena; Pulgarín, César; Fernández-Ibáñez, Pilar; Maldonado, Manuel I; Pérez-Estrada, Leonidas; Oller, Isabel; Gernjak, Wolfgang; Malato, Sixto

    2006-03-01

    In this paper, we present the photo-Fenton treatment in a solar pilot-plant scale of several EU priority hazardous substances (Alachlor, Atrazine, Chlorfenvinphos, Diuron and Isoproturon) dissolved in water. The results have been evaluated not only from the point of view of contaminant disappearance and mineralisation, but also of toxicity reduction and enhancement of biodegradability. Degradation was monitored by total organic carbon, pesticide concentration by HPLC-UV, inorganics released by ion chromatography, and biodegradability by the Zahn-Wellens (Z-W) test. The total volume of the solar photoreactor, composed of compound parabolic collectors with a total area of 4.16m2, was between 70 and 82 L. The treatment was shown to be effective, mineralising all of the pesticides tested, both alone and in mixtures. In order to find out the conditions for biocompatibility using the photo-Fenton reaction as a pre-treatment step, wastewater inoculated with unacclimated municipal sludge containing pesticides after certain degradation time was evaluated by the Z-W test. Biodegradability was enhanced (70% considered biodegradable) by the photo-Fenton treatment after 12-25min. It may be concluded that the photo-Fenton treatment consistently enhances biodegradability of wastewater containing pesticides.

  19. Effect of anionic surfactants on the process of Fenton degradation of methyl orange.

    Science.gov (United States)

    Yang, C W; Wang, D

    2009-01-01

    Fenton process has been shown to be very successful to remove dyes from water. However, the influence of other constituents in dyeing industry wastewater, such as Sodium Dodecyl Sulphate (SDS) surfactants, has not been investigated. In this study, the effect of SDS surfactant on the kinetics of Methyl Orange degradation undergoing Fenton process was investigated. Results show that Methyl Orange degradation rate decreased as SDS concentration increased, which was attributed to the consumption of hydroxyl radicals (OH) by surfactants and the formation of Methyl Orange-SDS complex. No evidence was found that the Methyl Orange degradation pathway was affected by the presence of SDS. The kinetics modelling indicates the reaction was the first-order reaction to Methyl Orange.

  20. Mineralization of Azo Dye Using Combined Photo-Fenton and Photocatalytic Processes under Visible Light

    Directory of Open Access Journals (Sweden)

    Selma K. Kuriechen

    2013-01-01

    Full Text Available Visible-light-assisted photodegradation of an azo dye, Reactive Red 180 (RR180, in the presence of nitrogen-doped TiO2 (N-TiO2 has been studied. The photodegradation of RR180 is evaluated through decolorization studies and total organic carbon analysis. The efficacy of hydrogen peroxide (H2O2, potassium peroxomonosulfate (oxone or PMS, and potassium peroxodisulfate (PDS in improving the photodegradation of the dye in the N-TiO2-RR180 system is also examined. The effect of combining photo-Fenton-like reaction with N-TiO2-mediated photodegradation of RR180 under visible light has been investigated. The photoactivity of N-TiO2-RR180-Fe3+/Cu2+-oxidant systems is compared with the individual techniques of photocatalysis and photo-Fenton-like reactions. The coupled system possesses superior photomineralization ability towards the abatement of RR180.

  1. Oxidation of Levafix CA reactive azo-dyes in industrial wastewater of textile dyeing by electro-generated Fenton's reagent.

    Science.gov (United States)

    El-Desoky, Hanaa S; Ghoneim, Mohamed M; El-Sheikh, Ragaa; Zidan, Naglaa M

    2010-03-15

    The indirect electrochemical removal of pollutants from effluents has become an attractive method in recent years. Removal (decolorization and mineralization) of Levafix Blue CA and Levafix Red CA reactive azo-dyes from aqueous media by electro-generated Fenton's reagent (Fe(2+)/H(2)O(2)) using a reticulated vitreous carbon cathode and a platinum gauze anode was optimized. Progress of oxidation (decolorization and mineralization) of the investigated azo-dyes with time of electro-Fenton's reaction was monitored by UV-visible absorbance measurements, Chemical oxygen demand (COD) removal and HPLC analysis. The results indicated that the electro-Fenton's oxidation system is efficient for treatment of such types of reactive dyes. Oxidation of each of the investigated azo-dyes by electro-generated Fenton's reagent up to complete decolorization and approximately 90-95% mineralization was achieved. Moreover, the optimized electro-Fenton's oxidation was successfully applied for complete decolorization and approximately 85-90% mineralization of both azo-dyes in real industrial wastewater samples collected from textile dyeing house at El-Mahalla El-Kobra, Egypt.

  2. Novel bio-electro-Fenton technology for azo dye wastewater treatment using microbial reverse-electrodialysis electrolysis cell

    DEFF Research Database (Denmark)

    Li, Xiaohu; Jin, Xiangdan; Zhao, Nannan

    2017-01-01

    Development of sustanaible technologies for treatment of azo dyes containing wastewaters has long been of great interest. In this study, we proposed an innovative concept of using microbial reverse-electrodialysis electrolysis cell (MREC) based Fenton process to treat azo dye wastewater....... In such MREC-Fenton integrated process, the production of H2O2 which is the key reactant of fenton-reaction was driven by the electrons harvested from the exoelectrogens and salinity-gradient between sea water and fresh water in MREC. Complete decolorization and mineralization of 400 mg L-1 Orange G...... was achieved with apparent first order rate constants of 1.15 ± 0.06 and 0.26 ± 0.03 h-1, respectively. Furthermore, the initial concentration of orange G, initial solution pH, catholyte concentration, high and low concentration salt water flow rate and air flow rate were all found to significantly affect...

  3. Disinfection of wastewater effluents with the Fenton-like process induced by electromagnetic fields.

    Science.gov (United States)

    Rodríguez-Chueca, J; Mediano, A; Ormad, M P; Mosteo, R; Ovelleiro, J L

    2014-09-01

    This research work is focused on the application and assessment of effectiveness of the Fenton-like processes induced by radiofrequency for the inactivation of faecal bacteria (Escherichia coli and Enterococcus sp.) present in treated urban wastewater effluents. Fenton processes were carried out at near neutral pH (pH 5) with different iron sources, such as iron salts (ferric chloride, 5, 50 and 100 mg/L Fe(3+)), magnetite (1 g/L) and clay (80 g/L), hydrogen peroxide (25 mg/L) and in absence and presence of radiofrequency. Two different electromagnetic field intensities (1.57 and 3.68 kA/m) were used in Fenton processes induced by radiofrequency. Different agents used in the Fenton processes induced by electromagnetic fields (iron source, hydrogen peroxide and RF) were analyzed individually and in combination under the same experimental conditions. First assays of ferromagnetic material/H2O2/radiofrequency processes achieved promising results in terms of bacterial inactivation. For instance, Fe(3+)/H2O2/Radiofrequency achieved a maximum level of E. coli inactivation of 3.55 log after 10 min of treatment. These results are higher than those obtained in absence of radiofrequency. The thermal activation of iron atoms allows the Fenton reaction to intensify, increasing the final yield of the treatment. On the other hand, different behavior was observed in the inactivation of E. coli and Enterococcus sp. due to the structural differences between Gram-negative and Gram-positive bacteria.

  4. Photo-Fenton treatment of a pesticide mixture simulating real wastewater and 4-nonylphenol

    Energy Technology Data Exchange (ETDEWEB)

    Gernjak, W.; Mentler, A.; Rodriguez, R.; Furhacker, M.; Malato, S.

    2003-07-01

    A simulated real wastewater containing a mixture of nine commercial pesticide formulations was degraded by the Photo-Fenton method in concentrating parabolic trough collectors at pilot-plant scale (helio man reactor at PSA) with varying initial iron concentrations (10-60 mg/L) and at two different temperatures (30 and 45 degree centigree). Independent of temperature and iron concentration 85% of the TOC could be degreed. Although the pH value was adjusted to 2.8 prior to ferrous sulfate addition, iron precipitated during the Photo-Fenton treatment (between 20 and 80%), the effect being pronounced stronger at elevated temperatures. TOC degradation rates increased confirming to increase of temperature and of iron concentration, if referred to dissolved iron. Around 20% more hydrogen peroxide was consumed at 45 degree centigree. The high radiation intensity achieved in the concentrating collector did not negatively affect the TOC degradation rates, as this is the case for UiO{sub 2} COD and VOD{sub 5} measurements showed that biodegradability during the Photo-Fenton treatment is enhanced from 15 to 37% of COD. Finally, FT-IR and X-ray diffraction measurements of the precipitated iron revealed a goethite crystal structure. Almost saturated solutions of 4-nonylphenol (2-3 mg/L) could be degraded by two orders of magnitude (Analytical detection limit reached) as well by TiO{sub 2} photo catalysis as by the Photo-Fenton method, the latter one being much quicker. Fenton reaction in the dark transformed between 40 and 80% of initial 4-nonylphenol into oxidized intermediates (1-5 mg/L ferrous iron applied). (Author) 12 refs.

  5. 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.

  6. 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.

  7. 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%.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. Fenton oxidation of 2, 4-and 2, 6-dinitrotoluene and acetone inhibition

    Institute of Scientific and Technical Information of China (English)

    Yiliang HE; Bin ZHAO; Joseph B.HUGHES; Sunh Soo HAN

    2008-01-01

    The performances and kinetic parameters of Fenton oxidation of 2, 4- and 2, 6-dinitrotoluene (DNT) in water-acetone mixtures and explosive contaminated soil washing-out solutions were investigated at a labor-atory scale. The experimental results show that acetone can be a significant hydroxyl radical scavenger and result in serious inhibition of Fenton oxidation of 2, 4- and 2, 6-DNT. Although no serious inhibition was found in con-taminated soil washing-out solutions, longer reaction time was needed to remove 2, 4- and 2, 6-DNT completely, mainly due to the competition of hydroxyl radicals. Fenton oxidation of 2, 4- and 2, 6-DNT fit well with the first-order kinetics and the presence of acetone also reduced DNT's degradation kinetics. Based on the com-parison and matching of retention time and ultraviolet (UV) spectra between high performance liquid chromato-graphy (HPLC) and standards, the following reaction pathway for 2, 4-DNT primary degradation was pro-posed: 2, 4-DNT→2, 4-dinitro-benzaldehyde→2, 4-dini-trobenzoic acid→1, 3-dinitrobenzene→3-nitrophenol.

  13. 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.

  14. Roles of TaON and Ta(3)N(5) in the visible-Fenton-like degradation of atrazine.

    Science.gov (United States)

    Du, Yingxun; Zhao, Lu; Zhang, Yuanyuan

    2014-02-28

    In this study, the roles of TaON and Ta3N5 in the degradation of atrazine by the visible-Fenton-like system were examined in detail. The TaON and Ta3N5 samples prepared by the nitridation of Ta2O5 and characterized by XRD, DRS, BET and PL analyses. The results showed that the TaON sample had weaker absorption in the visible region but higher specific surface area than the Ta3N5 sample. The degradation rate of atrazine in visible-TaON-Fenton-like system was 2.64 times than that in visible-Ta3N5-Fenton-like system. Both Fe(2+) and H2O2 could be reduced by eCB (electrons in the conduction band) in TaON or Ta3N5, while atrazine could not be oxidized by hVB (holes in the valance band). OH is the active species for the degradation of atrazine in visible-TaON/Ta3N5-Fenton-like systems. Majority of OH originated from Fenton reaction. After Fe(3+) was reduced by eCB to Fe(2+), Fe(2+) reacted quickly with H2O2 to generate OH. In addition, by capturing eCB, a little of H2O2 was reduced to yield OH, which contributed a small fraction of atrazine degradation. Based on the experimental results, the roles of TaON and Ta3N5 in the visible-Fenton-like system were proposed. And the higher photocatalytic activity of TaON than Ta3N5 was suggested to be due to the higher separation efficiency of electrons and holes, which may be related to the larger specific surface area.

  15. Novel active heterogeneous Fenton system based on Fe3-xMxO4 (Fe, Co, Mn, Ni): the role of M2+ species on the reactivity towards H2O2 reactions.

    Science.gov (United States)

    Costa, Regina C C; Lelis, M F F; Oliveira, L C A; Fabris, J D; Ardisson, J D; Rios, R R V A; Silva, C N; Lago, R M

    2006-02-28

    In this work, the effect of incorporation of M2+ species, i.e. Co2+, Mn2+ and Ni2+, into the magnetite structure to increase the reactivity towards H2O2 reactions was investigated. The following magnetites Fe3-xMnxO4, Fe3-xCoxO4 and Fe3-xNixO4 and the iron oxides Fe3O4, gamma-Fe2O3 and alpha-Fe2O3 were prepared and characterized by Mössbauer spectroscopy, XRD, BET surface area, magnetization and chemical analyses. The obtained results showed that the M2+ species at the octahedral site in the magnetite strongly affects the reactivity towards H2O2, i.e. (i) the peroxide decomposition to O2 and (ii) the oxidation of organic molecules, such as the dye methylene blue and chlorobenzene in aqueous medium. Experiments with maghemite, gamma-Fe2O3 and hematite, alpha-Fe2O3, showed very low activities compared to Fe3O4, suggesting that the presence of Fe2+ in the oxide plays an important role for the activation of H2O2. The presence of Co or Mn in the magnetite structure produced a remarkable increase in the reactivity, whereas Ni inhibited the H2O2 reactions. The obtained results suggest a surface initiated reaction involving Msurf2+ (Fe, Co or Mn), producing HO radicals, which can lead to two competitive reactions, i.e. the decomposition of H2O2 or the oxidation of organics present in the aqueous medium. The unique effect of Co and Mn is discussed in terms of the thermodynamically favorable Cosurf3+ and Mnsurf3+ reduction by Femagnetite2+ regenerating the active species M2+.

  16. 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.

  17. Effect of alkali cations on heterogeneous photo-Fenton process mediated by Prussian blue colloids.

    Science.gov (United States)

    Liu, Shou-Qing; Cheng, Shi; Feng, Lian-Rong; Wang, Xiao-Mei; Chen, Zhi-Gang

    2010-10-15

    This article evaluates Prussian blue (iron hexacyanoferrate) colloids as a heterogeneous photo-Fenton catalyst for the degradation of Rhodamine B. The emphasis is laid on the effects of alkali metal cations on the photo-Fenton process. The facts show that alkali cations strongly affect the degradation rate of organic species. The degradation rates of Rhodamine B, Malachite Green, and Methyl Orange in the presence of KCl, KNO(3), and K(2)SO(4), respectively, are faster than their degradation rates in the presence of the corresponding sodium salts. The average degradation rates of Rhodamine B in 0.2 M KCl, NaCl, RbCl, and CsCl solution, decline in sequence, and the rate in KCl solution is greater than that without any salt added deliberately. Thus, potassium ions accelerate the degradation rate, but sodium, rubidium, and cesium ions slow the rate. The order of the rates is R(K)>R>R(Na)>R(Rb)>R(Cs), which is consistent with that of the voltammetric oxidation currents of Prussian blue in the corresponding cation solutions. This phenomenon is attributed to the molecular recognition of the microstructure in Prussian blue nanoparticles to the alkali cations. The reaction mechanism of the photo-Fenton process has also been explored.

  18. 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.

  19. Fenton-like oxidation of 2,4,6-trinitrotoluene using different iron minerals.

    Science.gov (United States)

    Matta, Roger; Hanna, Khalil; Chiron, Serge

    2007-10-15

    Degradation of 2,4,6-trinitrotoluene (TNT) was investigated in presence of different oxidants (Fenton's reagent, sodium persulfate, peroxymonosulfate and potassium permanganate) and different iron minerals (ferrihydrite, hematite, goethite, lepidocrocite, magnetite and pyrite) either in aqueous solution or in soil slurry systems. Fenton's reagent was the only oxidant able to degrade TNT in solution (k(app)=0.0348 min(-1)). When using iron oxide as heterogeneous catalyst at pH 3, specific reaction rate constants per surface area were k(surf)=1.47.10(-3) L min(-1) m(-2) and k(surf)=0.177 L min(-1) m(-2) for magnetite and pyrite, respectively while ferric iron minerals were inefficient for TNT degradation. The major asset of iron mineral catalyzed Fenton-like treatment has been the complete oxidation of the pollutant avoiding the accumulation of possible toxic by-products. In soil slurry systems, 38% abatement of the initial TNT concentration (2 g/kg) was reached after 24 h treatment time at neutral pH. Rate limiting steps were the availability of soluble iron at neutral pH together with desorption of the TNT fraction sorbed on the clay mineral surfaces.

  20. 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.

  1. 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.

  2. Advanced treatment of biologically pretreated coal gasification wastewater by a novel heterogeneous Fenton oxidation process.

    Science.gov (United States)

    Zhuang, Haifeng; Han, Hongjun; Ma, Wencheng; Hou, Baolin; Jia, Shengyong; Zhao, Qian

    2015-07-01

    Sewage sludge from a biological wastewater treatment plant was converted into sewage sludge based activated carbon (SBAC) with ZnCl2 as activation agent, which was used as a support for ferric oxides to form a catalyst (FeOx/SBAC) by a simple impregnation method. The new material was then used to improve the performance of Fenton oxidation of real biologically pretreated coal gasification wastewater (CGW). The results indicated that the prepared FeOx/SBAC significantly enhanced the pollutant removal performance in the Fenton process, so that the treated wastewater was more biodegradable and less toxic. The best performance was obtained over a wide pH range from 2 to 7, temperature 30°C, 15 mg/L of H2O2 and 1g/L of catalyst, and the treated effluent concentrations of COD, total phenols, BOD5 and TOC all met the discharge limits in China. Meanwhile, on the basis of significant inhibition by a radical scavenger in the heterogeneous Fenton process as well as the evolution of FT-IR spectra of pollutant-saturated FeOx/BAC with and without H2O2, it was deduced that the catalytic activity was responsible for generating hydroxyl radicals, and a possible reaction pathway and interface mechanism were proposed. Moreover, FeOx/SBAC showed superior stability over five successive oxidation runs. Thus, heterogeneous Fenton oxidation of biologically pretreated CGW by FeOx/SBAC, with the advantages of being economical, efficient and sustainable, holds promise for engineering application.

  3. Electro-Fenton and photoelectro-Fenton degradations of the drug beta-blocker propranolol using a Pt anode: Identification and evolution of oxidation products

    Energy Technology Data Exchange (ETDEWEB)

    Isarain-Chavez, Eloy; Cabot, Pere Lluis; Centellas, Francesc; Rodriguez, Rosa Maria; Arias, Conchita; 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, 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)

    2011-01-30

    The beta-blocker propranolol hydrochloride has been degraded by electrochemical advanced oxidation processes like electro-Fenton (EF) and photoelectro-Fenton (PEF) using a single cell with a Pt anode and an air diffusion cathode (ADE) for H{sub 2}O{sub 2} electrogeneration and a combined system containing the above Pt/ADE pair coupled in parallel to a Pt/carbon-felt (CF) cell. Organics are mainly oxidized with hydroxyl radical ({center_dot}OH) formed from Fenton's reaction between added Fe{sup 2+} and electrogenerated H{sub 2}O{sub 2}. The PEF treatment in Pt/ADE-Pt/CF system yields almost total mineralization because {center_dot}OH production is enhanced by Fe{sup 2+} regeneration from Fe{sup 3+} reduction at the CF cathode and Fe(III) complexes with generated carboxylic acids are rapidly photodecarboxylated under UVA irradiation. Lower mineralization degree is found for PEF in Pt/ADE cell due to the little influence of UVA light on Fe{sup 2+} regeneration. The homologous EF processes are much less potent as a result of the persistence of Fe(III)-carboxylate complexes. Aromatic intermediates such as 1-naphthol, 1,4-naphthoquinone and phthalic acid and generated carboxylic acids such as pyruvic, glycolic, malonic, maleic, oxamic, oxalic and formic are identified. While chloride ion remains stable, NH{sub 4}{sup +} and NO{sub 3}{sup -} ions are released to the medium. A reaction sequence for propranolol hydrochloride mineralization is proposed.

  4. Remediation of petroleum-contaminated soil after composting by sequential treatment with Fenton-like oxidation and biodegradation.

    Science.gov (United States)

    Lu, Mang; Zhang, Zhongzhi; Qiao, Wei; Wei, Xiaofang; Guan, Yueming; Ma, Qingxia; Guan, Yingchun

    2010-04-01

    A laboratory study was conducted to enhance removal of residual contaminants after composting in a highly petroleum-contaminated soil by combining Fenton-like pretreatment with biodegradation. The contaminants were characterized by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) during soil treatment. The optimum molar ratio of H(2)O(2) and Fe(3+) was 300/1 determined in batch experiments. At the end of Fenton-like treatment, total dichloromethane-extractable organics (TEO) decreased from 32,400 to 21,800 mg kg(-1) soil, and the toxicity of soil was reduced greatly in the preoxidation process. A significant loss of the number of soil microorganisms was observed in the Fenton-like reaction. During the microbial treatment period, 50.6% of TEO was destroyed. Numerous varieties of polar compounds containing nitrogen and oxygen were identified by FT-ICR MS. The number of compounds containing two oxygen atoms dropped from 604 to 163 during Fenton-like oxidation, and increased again to 577 after biodegradation.

  5. Proposed Schedule for Fenton Hill Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Albright, James N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Brown, Donald W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    1990-10-22

    To help in planning Fenton Hill experimental operations in concert with preparations for the Long-Term Flow Test (LTFT) next summer, the following schedule is proposed. This schedule fits some of the realities of the next few months, including the Laboratory closure during the Holidays, the seismic monitoring tests in Roswell, and the difficulties of operating during the winter months. Whenever possible, cyclic pumping operations during the colder months will be scheduled so that the pump will be on during the late evening and early morning hours to prevent freezeup.

  6. Degradation of antibiotics norfloxacin by Fenton, UV and UV/H2O2.

    Science.gov (United States)

    Santos, Lucilaine Valéria de Souza; Meireles, Alexandre Moreira; Lange, Liséte Celina

    2015-05-01

    This study aimed to evaluate the degradation of the antibiotic norfloxacin, using direct photolysis (UV), photolysis with hydrogen peroxide (UV/H2O2) and Fenton's oxidation processes. Initially, it was evaluated the behavior of the antibiotic norfloxacin on direct photolysis, in order to see if the process could be a pertinent way to eliminate the drug in water treatment stations. The results showed that the use of direct photolysis was not effective in the degradation of the antibiotic, reaching a degradation rate of 85% and a mineralization rate of 2% in 7 h of reaction; leading to the formation of intermediates products. To optimize the UV treatment, it was used the combined UV/H2O2 process. Several concentrations of hydrogen peroxide (0.7, 1.4, 2.1, 2.8, 3.5 and 4.2 mmol/L) at pH 7 were tested. The concentration of 2.1 mmol/L reached a degradation rate of 100% in 100 min of reaction. Based on this result, the speed of the reaction at pH 2, 3, 5, and 10 was evaluated for that same concentration of H2O2. The shortest reaction time (60 min) was verified at pH 2 and 3. For the treatment using Fenton oxidation, a degradation rate of 60% of the compound and a mineralization rate of 55% was obtained in 60 min. The study revealed that the Fenton oxidation and UV/H2O2 can be used for norfloxacin removal, reaching respectively degradation rates of 100% and 60%, and mineralization rates of 55% and 32%.

  7. 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.

  8. Competitive removal of Cu-EDTA and Ni-EDTA via microwave-enhanced Fenton oxidation with hydroxide precipitation.

    Science.gov (United States)

    Lin, Qintie; Pan, Hanping; Yao, Kun; Pan, Yonggang; Long, Wei

    2015-01-01

    Ethylenediaminetetraacetic acid (EDTA) can form very stable complexes with heavy metal ions, greatly inhibiting conventional metal-removal technologies used in water treatment. Both the oxidation of EDTA and the reduction of metal ions in metal-EDTA systems via the microwave-enhanced Fenton reaction followed by hydroxide precipitation were investigated. The Cu(II)-Ni(II)-EDTA, Cu(II)-EDTA and Ni(II)-EDTA exhibited widely different decomplexation efficiencies under equivalent conditions. When the reaction reached equilibrium, the chemical oxygen demand was reduced by a microwave-enhanced Fenton reaction in different systems and the reduction order from high to low was Cu(II)-Ni(II)-EDTA ≈ Cu(II)-EDTA > Ni(II)-EDTA. The removal efficiencies of both Cu(2+) and Ni(2+) in Cu-Ni-EDTA wastewaters were much higher than those in a single heavy metal system. The degradation efficiency of EDTA in Cu-Ni-EDTA was lower than that in a single metal system. In the Cu-Ni-EDTA system, the microwave thermal degradation and the Fenton-like reaction created by Cu catalyzed H2O2 altered the EDTA degradation pathway and increased the pH of the wastewater system, conversely inhibiting residual EDTA degradation.

  9. 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.

  10. Activity and stability of Fenton-like species supported over different silica structures

    Energy Technology Data Exchange (ETDEWEB)

    Calleja, G.; Melero, J.A.; Martinez, F.; Molina, R. [Dept. of Chemical, Environmental and Materials Technology, ESCET, Rey Juan Carlos Univ., Mostoles (Madrid) (Spain)

    2003-07-01

    Different strategies of synthesis for the preparation of iron containing materials and using different silica supports (amorphous, mesostructured and zeolitic materials) have been evaluated with the purpose of enhancing the activity and stability of metal species in heterogeneous Fenton-like processes. Their catalytic performance in wet peroxide oxidation processes has been monitored in terms of phenol and total organic carbon (TOC) conversions, products distribution and degree of metal leaching into liquid phase reaction. The environment and type of iron species induce significant changes on the catalytic performance of the catalysts. (orig.)

  11. 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.

  12. Degradation kinetics and mechanisms of phenolin photo-Fenton process

    Institute of Scientific and Technical Information of China (English)

    何锋; 雷乐成

    2004-01-01

    Phenol degradation in photochemically enhanced Fenton process was investigated in this work. UV-VIS spectra of phenol degradation showed the difference between photo-Fenton process and UV/H2O2, which is a typical hydroxyl radical process. A possible pathway diagram for phenol degradation in photo-Fenton process was proposed, and a mathematical model for chemical oxygen demand (COD) removal was developed. Operating parameters such as dosage of H2O2 and ferrous ions, pH, suitable carrier gas were found to impact the removal of COD significantly. The results and analysis of kinetic parameters calculated from the kinetic model showed that complex degradation of phenol was the main pathway for removal of COD: while hydroxyl radicals acted weakly in the photo-Fenton degradation of phenol.

  13. Wastewater treatment process of organic impurities by Fenton reaction

    Directory of Open Access Journals (Sweden)

    Talgat Mauletuly

    2013-09-01

    Full Text Available The method is for the oxidative degradation of organic contaminants of natural, recycled and waste water. As oxidative degradation of the catalyst, compounds of iron, generated directly in the purification process, wherein the oxidation of the organic impurities by molecular oxygen, activated by a pair H2O2/Fe2 , and hydrogen peroxide taken in an amount of 30 - 40% of that stoichiometrically required. The proposed method has the following advantages: improved performance and efficiency of the water treatment while reducing the cost of its holding.

  14. Kinetics of acetaminophen degradation by Fenton oxidation in a fluidized-bed reactor.

    Science.gov (United States)

    de Luna, Mark Daniel G; Briones, Rowena M; Su, Chia-Chi; Lu, Ming-Chun

    2013-01-01

    Acetaminophen (ACT), an analgesic and antipyretic substance, is one of the most commonly detected pharmaceutical compound in surface waters and wastewaters. In this study, fluidized-bed Fenton (FB-Fenton) was used to decompose ACT into its final degradation products. The 1.45-L cylindrical glass reactor had inlet, outlet and recirculating sections. SiO(2) carrier particles were supported by glass beads with 2-4 mm in diameter. ACT concentration was determined by high performance liquid chromatography (HPLC). During the first 40 min of reaction, a fast initial ACT removal was observed and the "two-stage" ACT degradation conformed to a pseudo reaction kinetics. The effects of ferrous ion dosage and [Fe(2+)]/[H(2)O(2)] (FH ratio) were integrated into the derived pseudo second-order kinetic model. A reaction pathway was proposed based on the intermediates detected through SPME/GC-MS. The aromatic intermediates identified were hydroquinone, benzaldehydes and benzoic acids while the non-aromatic substances include alcohols, ketones, aldehydes and carboxylic acids. Rapid initial ACT degradation rate can be accomplished by high initial ferrous ion concentration and/or low FH ratio.

  15. 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.

  16. Efficient use of Fe metal as an electron transfer agent in a heterogeneous Fenton system based on Fe0/Fe3O4 composites.

    Science.gov (United States)

    Moura, Flávia C C; Araujo, Maria Helena; Costa, Regina C C; Fabris, José D; Ardisson, José D; Macedo, Waldemar A A; Lago, Rochel M

    2005-08-01

    In this work a novel heterogeneous Fenton system based on Fe(0)/Fe3O4 composites is described. The composites with several Fe(0)/Fe3O4 ratios were prepared by two different methods, i.e. mechanical alloying of Fe(0) and Fe3O4 powders and controlled reduction of Fe3O4 with H2. Reaction studies and detailed Conversion Electron Mössbauer surface characterization of the composites Fe(0)/Fe3O4, Fe(0), Fe3O4, alpha-Fe2O3 and gamma-Fe2O3 suggested that Fe2+surf species are essential to produce an active Fenton system. Kinetic studies for the oxidation of the dye methylene blue, used as an organic model molecule, and for the peroxide decomposition suggest that the reactions proceed via HO* radicals generated from Fe2+surf species and H2O2 in a Fenton like mechanism. The increase in activity caused by the addition of Fe(0) is discussed in terms of a creation of Fe2+surf species during the preparation of the composite and by an electron transfer mechanism from Fe(0) to Fe3+surf during the Fenton reaction to regenerate the Fe2+surf active species.

  17. 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.

  18. 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.

  19. Mature landfill leachate treatment by coagulation/flocculation combined with Fenton and solar photo-Fenton processes.

    Science.gov (United States)

    Amor, Carlos; De Torres-Socías, Estefanía; Peres, José A; Maldonado, Manuel I; Oller, Isabel; Malato, Sixto; Lucas, Marco S

    2015-04-09

    This work reports the treatment of a mature landfill leachate through the application of chemical-based treatment processes in order to achieve the discharge legal limits into natural water courses. Firstly, the effect of coagulation/flocculation with different chemicals was studied, evaluating the role of different initial pH and chemicals concentration. Afterwards, the efficiency of two different advanced oxidation processes for leachate remediation was assessed. Fenton and solar photo-Fenton processes were applied alone and in combination with a coagulation/flocculation pre-treatment. This physicochemical conditioning step, with 2 g L(-1) of FeCl3 · 6H2O at pH 5, allowed removing 63% of COD, 80% of turbidity and 74% of total polyphenols. Combining the coagulation/flocculation pre-treatment with Fenton reagent, it was possible to reach 89% of COD removal in 96 h. Moreover, coagulation/flocculation combined with solar photo-Fenton revealed higher DOC (75%) reductions than single solar photo-Fenton (54%). In the combined treatment (coagulation/flocculation and solar photo-Fenton), it was reached a DOC reduction of 50% after the chemical oxidation, with 110 kJ L(-1) of accumulated UV energy and a H2O2 consumption of 116 mM. Toxicity and biodegradability assays were performed to evaluate possible variations along the oxidation processes. After the combined treatment, the leachate under study presented non-toxicity but biodegradability increased.

  20. Degradation of Reactive Black 5 dye by CWPO using Fe/mining sand under photo-Fenton process

    Science.gov (United States)

    Amri, Nurulhuda; Nasuha, Norhaslinda; Halim, Siti Fatimah Abdul; Ngah, Khairuddin

    2015-05-01

    This present study was conducted to investigate the effectiveness of catalytic wet peroxide oxidation (CWPO) process using photo-Fenton method and the used of mining sand as support catalyst as well as to determine the optimum parameters and effect of catalyst wt%, pH, H2O2 concentration, initial dye concentration and catalyst dosage on RB 5 degradation. The Fe/mining sand was prepared by impregnation technique and a solar degradation of RB 5 carried out by mean photo-Fenton reaction promoted by solar energy. The dye degradation was monitored during the experimental runs through UV/Vis spectrophotometer. In this process, the reaction condition were optimized at 0.4 of catalyst wt%, pH 2, 4 mM of H2O2 concentration and 0.5 g of catalyst dosage which achieved degradation efficiency at 100% for the three experiments except catalyst dosage which achieved 97.54% respectively within 180 min. The degradation of RB 5 also decreased with the increasing of dye concentration with 10 mg/L achieved the optimum degradation of 99.93%. The results demonstrated that photo-Fenton method could effectively degrade RB 5 and reduce the operating cost by conducting the experiment at optimum conditions.

  1. NiFe(C2O4)x as a heterogeneous Fenton catalyst for removal of methyl orange.

    Science.gov (United States)

    Liu, Yucan; Zhang, Guangming; Chong, Shan; Zhang, Nan; Chang, Huazhen; Huang, Ting; Fang, Shunyan

    2017-05-01

    This paper studies a heterogeneous Fenton catalyst NiFe(C2O4)x, which showed better catalytic activity than Ni(C2O4)x and better re-usability than Fe(C2O4)x. The methyl orange removal efficiency was 98% in heterogeneous Fenton system using NiFe(C2O4)x. The prepared NiFe(C2O4)x had a laminated shape and the size was in the range of 2-4 μm, and Ni was doped into catalyst's structure successfully. The NiFe(C2O4)x had a synergistic effect of catalyst of 24.7 for methyl orange removal, and the dope of Ni significantly reduced the leaching of Fe by 77%. The reaction factors and kinetics were investigated. Under the optimal conditions, 0.4 g/L of catalyst dose and 10 mmol/L of hydrogen peroxide concentration, 98% of methyl orange was removed within 20 min. Analysis showed that hydroxyl radicals and superoxide radicals participated in the reaction. With NiFe(C2O4)x catalyst, the suitable pH range for heterogeneous Fenton system was wide from 3 to 10. The catalyst showed good efficiency after five times re-use. NiFe(C2O4)x provided great potential in treatment of refractory wastewater with excellent property.

  2. Development of MCM-41 based catalysts for the photo-Fenton's degradation of dye pollutants

    Science.gov (United States)

    Lam, Leung Yuk Frank

    The continuous advancement in most industries has resulted in serious water pollution problems. The industrial effluents contain a variety of highly toxic organics such as dye pollutants. Numerous processes have been demonstrated for treating such pollutants. Among them, photo-Fenton's reaction is effective for organic mineralization by hydroxyl radicals generated from the Fenton's reagents (Fe2+ and H2O2). However, there is a drawback in that it requires a separation system to recover the homogeneous ferrous ion in the treated wastewater. In this research, new heterogeneous Fenton's catalysts are developed to solve such a problem and to achieve an efficient mineralization of dye pollutants. Two methods for catalyst preparation, including sol-gel hydrothermal (SG) and metal-organic chemical vapor deposition (MOCVD) techniques, were studied in this work. For SG-prepared catalysts, the iron element was successfully doped into the MCM-41 structure. These catalysts demonstrated a good catalytic efficiency but leaching of metal ions from the developed catalyst was found. In the MOCVD technique, a rotated tubular reactor system was developed to synthesize Fe/MCM-41 catalyst with uniform metal dispersion. It was found that using oxygen as a carrier gas during metal deposition was able to increase the stability of the deposited metal. In degradation of a model dye pollutant, Orange II, a total of 85% TOC mineralization was achieved at pH 3. A disadvantage of using Fe/MCM-41 was the reduced efficiency at higher pH. Cu/MCM-41 was thus developed and showed better catalytic activities than Fe/MCM-41 at neutral pH. Having the specific catalytic properties of Fe/MCM-41 and Cu/MCM-41, bimetallic (Fe+Cu) catalysts supported on MCM-41 were developed which show better activities in the Orange II mineralization than those monometallic (Fe or Cu) catalysts. The preparation conditions of the catalysts were experimentally optimized. The effects of catalyst dosage, metal loading

  3. 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

  4. Hydroxylamine Promoted Goethite Surface Fenton Degradation of Organic Pollutants.

    Science.gov (United States)

    Hou, Xiaojing; Huang, Xiaopeng; Jia, Falong; Ai, Zhihui; Zhao, Jincai; Zhang, Lizhi

    2017-03-30

    In this study, we construct a surface Fenton system with hydroxylamine (NH2OH), goethite (α-FeOOH), and H2O2 (α-FeOOH-HA/H2O2) to degrade various organic pollutants including dyes (methyl orange, methylene blue, and rhodamine B), pesticides (pentachlorophenol, alachlor, and atrazine), and antibiotics (tetracycline, chloramphenicol, and lincomycin) at pH 5.0. In this surface Fenton system, the presence of NH2OH could greatly promote the H2O2 decomposition on the α-FeOOH surface to produce •OH without releasing any detectable iron ions during the alachlor degradation, which was different from some previously reported heterogeneous Fenton counterparts. Moreover, the •OH generation rate constant of this surface Fenton system was 102 - 104 times those of previous heterogeneous Fenton processes. The interaction between α-FeOOH and NH2OH was investigated with using attenuated total reflectance Fourier transform infrared spectroscopy and density functional theory calculations. The effective degradation of organic pollutants in this surface Fenton system was ascribed to the efficient Fe(III)/Fe(II) cycle on the α-FeOOH surface promoted by NH2OH, which was confirmed by X-ray photoelectron spectroscopy analysis. The degradation intermediates and mineralization of alachlor in this surface Fenton system were then systematically investigated using total organic carbon and ion chromatography, liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry. This study offers a new strategy to degrade organic pollutants, and also sheds light on the environmental effects of goethite.

  5. 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.

  6. UV/Fenton photo-oxidation of Drimarene Dark Red (DDR) containing textile-dye wastewater

    Science.gov (United States)

    Hudaya, T.; Anthonios, J.; Septianto, E.

    2016-11-01

    Textile dye wastewater contains organic pollutants which are non-biodegradable, characterized by low BOD/COD ratio of typically treat such wastewater, the destructive wastewater treatment methods which can be utilized are the Advanced Oxidation Processes (AOPs). One of the AOPs method which is the UV/H2O2/Fe2+ (or UV/Fenton) offers not only relatively low cost but also quite effective (in terms of color removal and reaction time) treatment. This particular research aimed to optimize the conditions of UV/Fenton photo-oxidation process for Drimarene Dark Red containing textile- dye wastewater. The two main operating conditions to be optimized were the initial concentration of H2O2 ranged between 0.022-0.078 %-w and the mol ratio of Fe2+: H2O2 was varied from 1: 13 up to 1: 45, using the Central Composite Design experimental matrix. The photo-oxidation was carried out at the optimum pH of 3 from some previous experiments. The best processing conditions of the photo-oxidation of Drimarene Dark Red (DDR) were found at the initial concentration of H2O2 at 0.050%-w and the mole ratio Fe2+: H2O2 of 1: 22. Under these conditions, the measured 2nd order pseudo-rate constantwas 0.021 M-1.min-1. The DDR color removal of 90% was surprisingly achievable within only 10 minutes reaction time.

  7. Application of the Fenton process in the elimination of helminth eggs.

    Science.gov (United States)

    Escobar-Megchún, Sandra Isabel; Nájera-Aguilar, Hugo Alejandro; González-Hilerio, Magaly; Gutiérrez-Jiménez, Javier; Gutiérrez-Hernández, Rubén Fernando; Rojas-Valencia, María Neftalí

    2014-12-01

    This study relates to a method for evaluating the degradation efficiency of Ascaris lumbricoides eggs through a Fenton reaction, using hydrogen peroxide (H2O2) at 100, 250, and 500 mg/L, ferrous sulfate (FeSO4) at 458 mg/L Fe(2+) and pH values of 3, 4.5, and 6. The experiments were conducted according to a 3(2) experimental design, with 1:1, 3:1, and 5:1 (H2O2/Fe(2+)) molar ratios. The oxidation and flocculation stages were performed at 130 rpm during 2 hours and at 25-30 rpm during 20 min, respectively. As a result of the Fenton reaction, an average of 91.2% Ascaris lumbricoides egg degradation was achieved at pH 6 using a 500 mg/L dose of H2O2 and a 3:1 (H2O2/Fe(2+)) molar ratio. Thus, this process is an alternative for eliminating parasites that are resistant to conventional disinfection processes and significantly reduces the human health hazard they represent.

  8. 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.

  9. Municipal Leachate Treatment by Fenton Process: Effect of Some Variable and Kinetics

    Directory of Open Access Journals (Sweden)

    Mohammad Ahmadian

    2013-01-01

    Full Text Available Due to complex composition of leachate, the comprehensive leachate treatment methods have been not demonstrated. Moreover, the improper management of leachate can lead to many environmental problems. The aim of this study was application of Fenton process for decreasing the major pollutants of landfill leachate on Kermanshah city. The leachate was collected from Kermanshah landfill site and treated by Fenton process. The effect of various parameters including solution pH, Fe2+ and H2O2 dosage, Fe2+/H2O2 molar ratio, and reaction time was investigated. The result showed that with increasing Fe2+ and H2O2 dosage, Fe2+/H2O2 molar ratio, and reaction time, the COD, TOC, TSS, and color removal increased. The maximum COD, TOC, TSS, and color removal were obtained at low pH (pH: 3. The kinetic data were analyzed in term of zero-order, first-order, and second-order expressions. First-order kinetic model described the removal of COD, TOC, TSS, and color from leachate better than two other kinetic models. In spite of extremely difficulty of leachate treatment, the previous results seem rather encouraging on the application of Fenton’s oxidation.

  10. Selective and sensitive colorimetric detection of stringent alarmone ppGpp with Fenton-like reagent.

    Science.gov (United States)

    Zheng, Lin Ling; Huang, Cheng Zhi

    2014-12-01

    Stringent alarmone, namely, guanosine 3'-diphosphate-5'-diphosphate (ppGpp), is a global regulator that plays a critical role in the survival, growth, metabolism, and many other vital processes of microorganisms. Because of its structural similarity to normal nucleotides, it is also a challenge for the selective and sensitive detection of ppGpp nowadays. Herein, we developed a colorimetric method for the selective detection of ppGpp by inhibiting the redox reaction between Fenton-like reagent (composed of Fe(3+) and H2O2) with 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS). Owing to the strong coordination affinity between ppGpp and Fe(3+), the chromogenic reaction between ABTS and Fenton-like reagent, occurred in aqueous medium at 37 °C and resulted in a bluish-green solution, which was inhibited with the addition of ppGpp. This phenomenon forms the basis for the colorimetric detection of ppGpp, with a detection limit of 0.19 μM and good selectivity for ppGpp over other nucleotides and anions. Furthermore, the results could be visualized by the naked eye, and the sensitivity of the naked-eye observation could even be further improved with the aid of the introduction of a background color.

  11. 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.

  12. 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.

  13. 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.

  14. Doxycycline Degradation by the Oxidative Fenton Process

    Directory of Open Access Journals (Sweden)

    Alexandre A. Borghi

    2015-01-01

    Full Text Available Doxycycline is a broad-spectrum tetracycline occurring in domestic, industrial, and rural effluents, whose main drawback is the increasing emergence of resistant bacteria. This antibiotic could be degraded by the so-called Fenton process, consisting in the oxidation of organic pollutants by oxygen peroxide (H2O2 in the presence of Fe2+. Experiments were performed according to an experimental Rotational Central Composite Design to investigate the influence of temperature (0–40.0°C, H2O2 concentration (100–900 mg/L, and Fe2+ concentration (5–120 mg/L on residual doxycycline and total organic carbon concentrations. Whereas the final residual doxycycline concentration ranged from 0 to 55.8 mg/L, the oxidation process proved unable to reduce the total organic carbon by more than 30%. The best operating conditions were concentrations of H2O2 and Fe2+ of 611 and 25 mg/L, respectively, and temperature of 35.0°C, but the analysis of variance revealed that only the first variable exerted a statistically significant effect on the residual doxycycline concentration. These results suggest possible application of this process in the treatment of doxycycline-containing effluents and may be used as starting basis to treat tetracycline-contaminated effluents.

  15. Fenton oxidation and combined Fenton-microbial treatment for remediation of crude oil contaminated soil in Assam - India.

    Science.gov (United States)

    Buragohain, Surabhi; Deka, Dibakar Chandra; Devi, Arundhuti

    2013-10-01

    The study is aimed at the remediation of soil spiked with crude oil (5%) by employing Fenton oxidation, biological treatment and combined Fenton-biological treatment. A spiked concentration of 5% crude oil was selected on the basis of contamination levels of 0-5% as found in the soil of upper Assam oil fields (India). The degradation of the aliphatic fraction (C14-C28) of the crude oil was investigated by gas chromatography. Fenton oxidation was carried out at different pH (3 to 8) in a laboratory batch reactor and maximum oxidative degradation was observed at pH 3-5. At pH 3, single Fenton oxidation resulted in 36 and 57% degradation in 5 and 10 days respectively. Biological treatment (with Fusarium solani) and combined Fenton-biological treatment were carried out with a one month incubation period. Biological treatment alone brought about 61% degradation of the crude oil while the combined process could achieve as much as 75% degradation of the aliphatic fractions of the crude oil.

  16. Degradation of disperse azo dyes from waters by solar photoelectro-Fenton

    Energy Technology Data Exchange (ETDEWEB)

    Salazar, Ricardo [Departamento de Ciencias del Ambiente, Facultad de Quimica y Biologia, Universidad de Santiago de Chile, USACh, Casilla 40, Correo 33, Santiago (Chile); 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); Ureta-Zanartu, M.S. [Departamento de Ciencias del Ambiente, Facultad de Quimica y Biologia, Universidad de Santiago de Chile, USACh, Casilla 40, Correo 33, Santiago (Chile); 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)

    2011-07-15

    Highlights: > Reactive azo dyes are almost totally mineralized by solar photoelectro-Fenton. > The process yields high current efficiencies and low energy consumptions. > It is more efficient and inexpensive by decreasing current and increasing dye content. > Nitrate ions are the main inorganic ions released during the mineralization process. > The process is also effective for the remediation of textile dyeing solutions. - Abstract: Solutions of the azo dyes Disperse Red 1 (DR1) and Disperse Yellow 3 (DY3), commonly used in the Chilean textile industry, in 0.1 mol dm{sup -3} Na{sub 2}SO{sub 4} and 0.5 mmol dm{sup -3} Fe{sup 2+} of pH 3.0 were comparatively degraded by electro-Fenton (EF) and solar photoelectro-Fenton (SPEF) using a 2.5 dm{sup 3} recirculation flow plant containing a BDD/air-diffusion cell coupled with a solar photoreactor. Organics were oxidized in EF with hydroxyl radicals formed at the anode surface from water oxidation and in the bulk from Fenton's reaction between electrogenerated H{sub 2}O{sub 2} and added Fe{sup 2+}. The oxidizing power of SPEF was enhanced by the additional production of hydroxyl radicals from the photolysis of Fe(III) hydrated species and the photodecomposition of Fe(III) complexes with intermediates by UV light of solar irradiation. Total decolorization, complete dye removal and almost overall mineralization for both dye solutions were only achieved using the most potent SPEF process, yielding higher current efficiencies and lower energy consumptions than EF. Final carboxylic acids like pyruvic, acetic, oxalic and oxamic were detected during the SPEF treatments. NO{sub 3}{sup -} ion was released as inorganic ion. The use of a solution pH of 2.0-3.0 at 50 mA cm{sup -2} was found preferable for SPEF. Synthetic textile dyeing solutions containing the dyes were treated under these conditions yielding lower decolorization rate, slower dye removal and smaller mineralization degree than only using 0.1 mol dm{sup -3} Na

  17. Investigation of acid red 88 oxidation in water by means of electro-Fenton method for water purification.

    Science.gov (United States)

    Özcan, Ali; Gençten, Metin

    2016-03-01

    In this study, electro-Fenton method was applied to acid red 88 (AR88) containing aqueous solutions for the removal of it from water. The mineralization of AR88 has been achieved by oxidation with hydroxyl radicals. These radicals were produced simultaneously by the electro-Fenton method using an electrochemical cell including a carbon felt cathode and a platinum anode. Applied current and concentrations of catalyst and supporting electrolyte were optimized to obtain the best effective parameters of 500 mA, 0.1 mM and 75 mM, respectively. The absolute rate constant for the oxidation reaction of AR88 with hydroxyl radical was determined as (1.57 ± 0.06) x 10(10) M(-1) s(-1). Total organic carbon (TOC) analysis was performed to determine whether the organics were converted to carbon dioxide or not. A two-hour electrolysis at 500 mA is enough to remove 87% of initial TOC values of 0.25 mM AR88 solution. Electro-Fenton treatment of AR88 led to the formation of five aromatic intermediates, five short-chain carboxylic acids and three inorganic ions. Identified intermediates and complete mineralization of AR88 allowed us to propose a mineralization pathway for first time in the literature.

  18. Visible Light Assisted Heterogeneous Fenton-like Degradation of Organic Pollutant via α-FeOOH/Mesoporous Carbon Composites.

    Science.gov (United States)

    Qian, Xufang; Ren, Meng; Zhu, Yao; Yue, Dongting; Han, Yu; Jia, Jinping; Zhao, Yixin

    2017-03-03

    A α-FeOOH/mesoporous carbon (α-FeOOH/MesoC) composite prepared by in situ crystallization of adsorbed ferric ions within carboxyl functionalized mesoporous carbon was developed as a novel visible light assisted heterogeneous Fenton-like catalyst. The visible light active α-FeOOH nanocrystals were encapsulated in the mesoporous frameworks accompanying with surface attached large α-FeOOH microcrystals via C-O-Fe bonding. Assisting with visible light irradiation on α-FeOOH/MesoC, the mineralization efficiency increased owing to the photocatalytic promoted catalyzing H2O2 beyond the photo-thermal effect. The synergistic effect between α-FeOOH and MesoC in α-FeOOH/MesoC composite improved the mineralization efficiency than the mixture catalyst of α-FeOOH and MesoC. The iron leaching is greatly suppressed on the α-FeOOH/MesoC composite. Interestingly, the reused α-FeOOH/MesoC composites showed much higher phenol oxidation and mineralization efficiencies than the fresh catalyst and homogeneous Fenton system (FeSO4/H2O2). The XPS, XRD, FTIR and textural property results reveal that the great enhancement comes from the interfacial emerged oxygen containing groups between α-FeOOH and MesoC after the first heterogeneous Fenton-like reaction. In summary, visible light induced photocatalysis assisted heterogeneous Fenton-like process in the α-FeOOH/MesoC composite system improved the HO• production efficiency and Fe(III)/Fe(II) cycle and further activated the interfacial catalytic sites, which finally realize an extraordinary higher degradation and mineralization efficiency.

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

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Syllos S. da [Departamento Engenharia Quimica, NUPEG, Universidade Federal do Rio Grande do Norte, Campus Universitario, Lagoa Nova, Natal 59066-800, RN (Brazil); Chiavone-Filho, Osvaldo, E-mail: osvaldo@eq.ufrn.br [Departamento Engenharia Quimica, NUPEG, Universidade Federal do Rio Grande do Norte, Campus Universitario, Lagoa Nova, Natal 59066-800, RN (Brazil); Barros Neto, Eduardo L. de [Departamento Engenharia Quimica, NUPEG, Universidade Federal do Rio Grande do Norte, Campus Universitario, Lagoa Nova, Natal 59066-800, RN (Brazil); Nascimento, Claudio A.O. [Departamento de Engenharia Quimica, Escola Politecnica, Universidade de Sao Paulo, Cidade Universitaria, Sao Paulo 05508-900, SP (Brazil)

    2012-01-15

    Highlights: Black-Right-Pointing-Pointer 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. Black-Right-Pointing-Pointer We have selected xylene as representative contaminant due to properties of toxicity, solubility in water and vapor pressure. Black-Right-Pointing-Pointer 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{sup -1} for the surfactant EO 7. Degradation efficiencies of organic loading were assessed using factorial planning. Statistical data analysis shows that H{sub 2}O{sub 2} 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.

  20. Steel dust catalysis for Fenton-like oxidation of polychlorinated dibenzo-p-dioxins.

    Science.gov (United States)

    Lee, Jae-Min; Kim, Ji-Hun; Chang, Yoon-Young; Chang, Yoon-Seok

    2009-04-15

    An advanced oxidation process (AOP) for degrading toxic contaminants, specifically polychlorinated dibenzo-p-dioxins (PCDDs), was developed to utilize steel dust, a steel industry by-product, as the heterogenous catalyst for a Fenton-like oxidation. The steel dust was treated using a chemical acid etchant (HCl) and ultrasound to remove surface anchored groups, reduce aggregation, and thereby increase the specific surface areas, resulting in increased access to catalytic sites. The removal of PCDD was optimized through various reaction conditions. The removal percentage of 1,2,3,4-tetrachlorintated dibenzo-p-dioxins (1,2,3,4-TCDD, 3.1 microM) after 3 h of Fenton-like oxidation under the conditions of 3 g/L (88 mM) H(2)O(2) and pH 3 was approximately 97% with 10 g/L of steel dust, compared to approximately 99% when 5 g/L metallic iron was used as a control. When a PCDD mixture (0.5-0.7 nM) was treated, 10 g/L (92 mM) steel dust achieved approximately 88% removal, comparable to the removal with 5 g/L (89 mM) Fisher iron with 3 g/L (88 mM) H(2)O(2.) These results indicate that the steel dust is a potentially viable catalyst for removing PCDDs from contaminated water.

  1. 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.

  2. Formaldehyde degradation in the presence of methanol by photo-Fenton process.

    Science.gov (United States)

    Kajitvichyanukul, Puangrat; Lu, Ming-Chun; Jamroensan, Aditsuda

    2008-02-01

    In this study, the photo-Fenton process for the degradation of formaldehyde was investigated in lab-scale experiments. Results showed that methanol, the additive chemical in a commercial product of formaldehyde, was also decomposed during the formaldehyde oxidation reaction. The oxidation reaction was in three-stages. The first stage was the Fe(2+)/H(2)O(2) reaction in which both formaldehyde and methanol were swiftly decomposed. The second and the third stages exerted a somewhat less rapid degradation of both chemicals. The first stage of the oxidation reaction can be discussed by means of the initial average rate and the third stage or Fe(3+)/H(2)O(2) stage was found to follow the first order reaction rate. The reaction was influenced by the initial pH, the concentration of hydrogen peroxide, the amount of ferrous ions. The initial pH at 2.6 provided the highest removal efficiencies in this system. In addition, the competition between formaldehyde and methanol was investigated and described as r(m)/r(f), where r(m) and r(f) were the initial rates of methanol and formaldehyde, respectively. The addition of methanol exhibited a competitive effect on formaldehyde degradation. The removal of formaldehyde decreased with increasing methanol concentration. At the high concentrations of methanol, the oxidation reaction of formaldehyde was repressed. It appears that all values of r(m)/r(f) obtained from the experiments are lower than the theoretical values.

  3. Fenton Redox Chemistry: Arsenite Oxidation by Metallic Surfaces

    NARCIS (Netherlands)

    Borges Freitas, S.C.; Van Halem, D.; Badruzzaman, A.B.M.; Van der Meer, W.G.J.

    2014-01-01

    Pre-oxidation of As(III) is necessary in arsenic removal processes in order to increase its efficiency. Therefore, the Fenton Redox Chemistry is defined by catalytic activation of H2O2 and currently common used for its redox oxidative properties. In this study the effect of H2O2 production catalysed

  4. 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

  5. Comparison of ultraviolet radiation/hydrogen peroxide, Fenton and photo-Fenton processes for the decolorization of reactive dyes

    Directory of Open Access Journals (Sweden)

    Radović Miljana D.

    2015-01-01

    Full Text Available The effectivness of UV/H2O2 process, Fenton and photo-Fenton process at decolorization of commercially important textile dyes Reactive Orange 4 (RO4 and Reactive Blue 19 (RB19 was evaluated. The effect of operational condition such as initial pH, initial H2O2 concentration, initial Fe2+ concentration and initial dye concentration on decolorization of RO4 and RB19 was studied. The photo-Fenton process is found to be more efficient than UV/H2O2 and Fenton process for decolorization of simulated dye bath effluent and solutions of the dyes in water alone under optimum conditions. In simulated dye bath the removal efficiency was slightly lower than for the solutions of the dyes in water alone for both dyes types. The results revealed that the tested advanced oxidation processes were very effective for decolorization of RO4 and RB19 in aqueous solution. [Projekat Ministarstva nauke Republike Srbije, br. TR34008

  6. 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.

  7. 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.

  8. Study on the removal of urea in wastewater using Fenton reagent

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The great amount of NH3-N produced in biological hydrolysis process of high concentration urea can inhibit the growth of microorganisms. In allusion to this problem, the Fenton reagent was used to treat high concentration urea wastewater. And the optimum conditions of this experiment were employed as follows: Fe (Ⅱ) -H2O2mole ratio was 1/3.53, H2O2 was 4 mL (corresponding to 35.30 mmol) , pH was 3.0 -3.5. Then the experiment shows that the urea concentration decreases from 500 mg/L to less than 2 mg/L, or is even not detected; under the same dose of H2O2 , repetitious addition does better than one-off addition; the reaction time within one minute or to be prolonged has little influence on removal effect. The results verify feasibility of this method.

  9. 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

    2016-07-04

    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.

  10. 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

    In this paper, the application of Fenton oxidation process for the decolorization of an azo dye Direct Blue 15 (DB15) in aqueous solution was investigated. The effect of initial pH, dosage of H2O2, H2O2/Fe2+ and H2O2/dye ratios and the reaction temperature on the decolorization efficiency...... and 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...... rights reserved....

  11. 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.

  12. Dewatering and removal of metals from urban anaerobically digested sludge by Fenton's oxidation.

    Science.gov (United States)

    Fontmorin, J-M; Sillanpää, Mika

    2017-02-01

    In this study, the relevance of Fenton's reaction for the treatment of urban anaerobically digested sludge was investigated. In a first part, the impact of the oxidation process on the improvement of the sludge dewaterability was studied. In a second part, the removal of heavy metals from the sludge was examined. Fenton's reaction was carried out with increasing concentrations of Fe(2+) and H2O2 in 1:10 and 1:1 ratios. Dewaterability of the raw sludge was highly improved: the addition of 36 mM Fe(2+) and 360 mM H2O2 led to specific cake resistance (SCR) and capillary suction time (CST) reductions of 99.8% and 98.8%, respectively. Indeed, under these conditions, SCR and CST of respectively 1.04 × 10(11) m kg(-1) and 18.5 ± 0.2 s were measured, and the treated sludge could be considered as having 'good dewaterability'. A significant impact was also observed on the removal of heavy metals from the sludge. After 1-h oxidation, Cd, Cr, Cu, Pb and Zn could be removed by 81.1 ± 0.1%, 25.1 ± 0.1%, 87.2 ± 1.1%, 77.3 ± 4.8% and 99.6 ± 0.3%, respectively. These results were consistent with the heavy metals' fractions in the sludge. It could be concluded that the addition of Fe(2+) and H2O2 in a 1:10 ratio was more effective than in a 1:1 ratio. The results were consistent with the extracellular polymeric substance (EPS) contents in raw and treated sludge, since loosely bound EPS decreased significantly after the treatment.

  13. Anodic Fenton process assisted by a microbial fuel cell for enhanced degradation of organic pollutants.

    Science.gov (United States)

    Liu, Xian-Wei; Sun, Xue-Fei; Li, Dao-Bo; Li, Wen-Wei; Huang, Yu-Xi; Sheng, Guo-Ping; Yu, Han-Qing

    2012-09-15

    The electro-Fenton process is efficient for degradation of organic pollutants, but it suffers from the high operating costs due to the need of power investment. Here, a new anodic Fenton system is developed for energy-saving and efficient treatment of organic pollutants by incorporating microbial fuel cell (MFC) into an anodic Fenton process. This system is composed of an anodic Fenton reactor and a two-chamber air-cathode MFC. The power generated from a two-chamber MFC is used to drive the anodic Fenton process for Acid Orange 7 (AO7) degradation through accelerating in situ generation of Fe(2+) from sacrificial iron. The kinetic results show that the MFC-assisted anodic Fenton process system had a significantly higher pseudo-first-order rate constant than those for the chemical Fenton methods. The electrochemical analysis reveals that AO7 did not hinder the corrosion of iron. The anodic Fenton process was influenced by the MFC performance. It was also found that increasing dissolved oxygen in the cathode improved the MFC power density, which in turn enhanced the AO7 degradation rate. These clearly demonstrate that the anodic Fenton process could be integrated with MFC to develop a self-sustained system for cost-effective and energy-saving electrochemical wastewater treatment.

  14. Photocatalytic degradation of 5-nitro-1,2,4-triazol-3-one NTO in aqueous suspension of TiO2. Comparison with Fenton oxidation.

    Science.gov (United States)

    Le Campion, L; Giannotti, C; Ouazzani, J

    1999-03-01

    5-nitro-1,2,4-triazol-3-one (NTO) is a powerful insensitive explosive, present in industrial waste waters. A remediation method based on photochemical decomposition and Fenton oxidation of NTO has been evaluated by monitoring the mineralization of 14C-labelled NTO. The TiO2-catalyzed photodegradation (lambda > 290 nm, TiO2 0.4 g/l, NTO 150 mg/l)) leads to the complete mineralization of NTO in 3 hours. This degradation involves a simultaneous denitrification and ring scission of NTO leading to nitrites, nitrates and carbon dioxide. No significant photo-degradation of NTO was detected in the absence of the catalyst. Long term irradiation over one week, leads to a complete degradation of concentrated NTO (5 g/l), suggesting that this method could be useful to clean-up NTO wastes. Fenton oxidation offers an efficient cost-effective method for NTO remediation. This reaction is faster that the TiO2 catalyzed photolysis and find application on the mineralization of high concentrations of NTO (15 g/l). Fenton oxidation provokes ring cleavage and subsequent elimination of the two carbon atoms of NTO as CO2. During this reaction, the nitro group is completely transformed into nitrates.

  15. An oxidative desulfurization method using ultrasound/Fenton's reagent for obtaining low and/or ultra-low sulfur diesel fuel

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Yongchuan; Qi, Yutai [Department of Applied Chemistry, School of Science, Harbin Institute of Technology, Harbin 115001 (China); Zhao, Dezhi [Department of Petroleum Chemical Engineering, Liaoning Shihua University, Fushun 113001 (China); Zhang, Huicheng [Fushun Research Institute of Petroleum and Petrochemicals of SINOPEC Corp., Fushun 113001 (China)

    2008-10-15

    The total development trend in the world is towards continuously lower of sulfur content as a quality standard of diesel fuels. Integrating of an oxidative desulfurization unit with a conventional hydrotreating unit can bring benefits to producing low and/or ultra-low sulfur diesel fuels. Using the hydrotreated Middle East diesel fuel as a feedstock, four processes of the oxidative desulfurization have been studied: a hydrogen peroxide-acetic acid system and a Fenton's reagent system both without/with ultrasound. Results showed that the oxidative desulfurization reaction mechanics fitted apparent first-order kinetics. The addition of Fenton's reagent could enhance the oxidative desulfurization efficiency for diesel fuels and sono-oxidation treatment in combination with Fenton's reagent shows a good synergistic effect. Under our best operating condition for the oxidative desulfurization: temperature 313 K, ultrasonic power 200 W, ultrasonic frequency 28 kHz, Fe{sup 2+}/H{sub 2}O{sub 2} 0.05 mol/mol, pH 2.10 in aqueous phase and reaction time 15 min, the sulfur content in the diesel fuels was decreased from 568.75 {mu}g/g to 9.50 {mu}g/g. (author)

  16. 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.

  17. Electro-Fenton pretreatment for the improvement of tylosin biodegradability

    OpenAIRE

    Ferrag-Siagh, Fatiha; Fourcade, Florence; Soutrel, Isabelle; Aït-Amar, Hamid; Djelal, Hayet; Amrane, Abdelatif

    2014-01-01

    International audience; The feasibility of an electro-Fenton process to treat tylosin (TYL), a non-biodegradable antibiotic, was examined in a discontinuous electrochemical cell with divided cathodic and anodic compartments. Only 15 min electrolysis was needed for total tylosin degradation using a carbon felt cathode and a platinum anode; while 6 h electrolysis was needed to achieve high oxidation and mineralization yields, 96 and 88 % respectively. Biodegradability improvement was shown sinc...

  18. Rapid decolorization and mineralization of simulated textile wastewater in a heterogeneous Fenton like system with/without external energy.

    Science.gov (United States)

    Zhou, Tao; Lu, Xiaohua; Wang, Jia; Wong, Fook-Sin; Li, Yaozhong

    2009-06-15

    A novel Fenton like system, employing Zero Valent Iron (ZVI) and air bubbling, was developed to treat a simulated textile wastewater containing azo dye Reactive Black 5 (RB5) and Ethylenediaminetetraacetic acid (EDTA). By dioxygen activation, H(2)O(2) was self-produced continuously in the system through a series of iron-EDTA ligands reactions. After 3h reaction, the removal rates of RB5, EDTA, Total Organic Carbon (TOC), and Chemical Oxygen Demand (COD) were 100%, 96.5%, 68.6% and 92.2%, respectively. The effects of pH, atmosphere as well as the initial concentration of RB5, EDTA and ZVI were also investigated. Two types of external energy-Ultrasound (US) and Ultraviolet (UV) were introduced into the Fenton like system, respectively. The effect of these external energies on the degradation of the wastewater was assessed. It was demonstrated that US presented significant synergistic effect on the degradation and mineralization of both RB5 and EDTA, while UV could not achieve any improvement.

  19. 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.

  20. Optimization of the Parameters Influencing the Photo-Fenton Process for the Decolorization of Reactive Red 198 (RR198

    Directory of Open Access Journals (Sweden)

    Dehghani

    2015-04-01

    Full Text Available Background Reactive dyes, anionic compounds with high water solubility, are widely used in textile industries. Objectives The present study aimed to assess the feasibility of the photo-Fenton process in removing Reactive Red 198 dye from aqueous solutions and determine the optimal conditions for maximum removal. Materials and Methods This study was performed on a laboratory scale using a 4-liter photochemical reactor. The spectrophotometer DR5000 (wavelength 520 nm was used to determine the dye concentration. The effect of the influencing parameters, including pH (3–9, Fe (II concentration (10–200 mg/L, H2O2 concentration (25 - 150 mg/L, initial dye concentration (50–200 mg/L, and reaction time (15 - 120 minutes were studied. Results According to the results, the photo-Fenton (UV/ H2O2/Fe (II process significantly removed dye from the aqueous solution. The Reactive Red 198 dye removal efficiency from aqueous solutions was more than 99% at optimal conditions (pH = 3, Fe (II = 10 mg/L, H2O2 = 75 mg/L, initial dye concentration = 50 mg/L, and reaction time = 120 minutes. Conclusions The present study demonstrated that the UV/ H2O2/Fe (II process could be used as an efficient, reliable method for removing Reactive Red 198 dye from textile wastewater.

  1. Sequential Fenton oxidation and hydrothermal treatment to improve the effect of pretreatment and enzymatic hydrolysis on mixed hardwood.

    Science.gov (United States)

    Jeong, So-Yeon; Lee, Jae-Won

    2016-01-01

    Sequential Fenton oxidation (FO) and hydrothermal treatment were performed to improve the effect of pretreatment and enzymatic hydrolysis of mixed hardwood. The molar ratio of the Fenton reagent (FeSO4·7H2O and H2O2) was 1:25, and the reaction time was 96h. During the reaction, little or no weight loss of biomass was observed. The concentration of Fe(2+) was determined and was found to increase continuously during FO. Hydrothermal treatment at 190-210°C for 10-80min was performed following FO. Sequential FO and hydrothermal treatment showed positive effects on pretreatment and enzymatic hydrolysis. Xylose concentration in the hydrolysate was as high as 14.16g/L when FO-treated biomass was treated at 190°C, while its concentration in the raw material was 3.72g/L. After 96h of enzymatic hydrolysis, cellulose conversion in the biomass obtained following sequential treatment was 69.58-79.54%. In contrast, the conversion in the raw material (without FO) was 64.41-67.92%.

  2. 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.

  3. 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.

  4. 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.

  5. Influence of the operating conditions on highly oxidative radicals generation in Fenton's systems.

    Science.gov (United States)

    Ciotti, Cesare; Baciocchi, Renato; Tuhkanen, Tuula

    2009-01-15

    In this work, an indirect method for estimating the total amount and concentration of oxidative radicals in aqueous and slurry-phase Fenton's systems was developed. This method, based on the use of benzoic acid as probe compound, was applied for evaluating the effect of the operating conditions on the radicals amount produced, their production efficiency (i.e. moles of radicals generated per mole H2O2 and their concentration. A Rotatable Central Composite design (RCC) was used to select the operating conditions in order to get a statistically meaningful data set. Hydrogen peroxide and ferrous ion concentrations ranged between 0.2-1mM and 0.2-0.5mM, respectively; humic acid concentration between 0 and 15mg/L, whereas the soil/water weight ratio in slurry-phase systems between 1:10 and 9:10. The probe compound concentration was 9 or 0.1mM in experiments aimed to evaluate the total amount or concentration of oxidative radicals, respectively. The obtained results indicated that the amount of radicals generated in both aqueous and soil slurry Fenton's system increased with higher H2O2 concentration and, more specifically, that their production efficiency increased with increasing Fe(II):H2O2 molar ratio. Addition of dissolved organic compounds as humic acid did not notably affect the oxidative radicals amount and concentration. On the contrary, a one order of magnitude reduction in both radicals amount generated and concentration was observed when soil was added to the reaction environment.

  6. Fenton and photo-Fenton treatment of a synthetic tannin used in leather tannery: a multi-approach study.

    Science.gov (United States)

    Lofrano, G; Meriç, S; Belgiorno, V; Nikolaou, A; Napoli, R M A

    2007-01-01

    The aim of this work was to compare the behaviour of Fenton and photo-Fenton (UV-A, UV-C) processes to treat synthetic tannin (syntan) used in leather tannery which is one of the most polluting industries, releasing many xenobiotics. Both oxidation processes were performed at pH 3.0 and temperature 40-45 degrees C, which is the original temperature of the re-tanning process, in synthetic solutions containing 100 and 300 mg/L of COD equivalent of syntan. The efficiency of the applied oxidation processes was monitored by chemical oxygen demand (COD), oxidation redox potential (ORP) and aromaticity (UV280) and double bond (UV254) absorbance measurements. Acute toxicity test on Daphnia magna was performed to monitor toxicity in untreated and treated syntan solution. Gas chromatography-mass spectrometry (GC-MS) was applied to identify by-products of partial oxidation occurring in treated samples. The effective ratio of H2O2/FeSO4 for photo-Fenton processes was found to be feasible in terms of reagents used in the process.

  7. Preparation of natural pyrite nanoparticles by high energy planetary ball milling as a nanocatalyst for heterogeneous Fenton process

    Energy Technology Data Exchange (ETDEWEB)

    Fathinia, Siavash [Department of Mining Engineering, Faculty of Engineering and Technology, Imam Khomeini International University, Qazvin (Iran, Islamic Republic of); Research Laboratory of Advanced Water and Wastewater Treatment Processes, Department of Applied Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz (Iran, Islamic Republic of); Fathinia, Mehrangiz [Research Laboratory of Advanced Water and Wastewater Treatment Processes, Department of Applied Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz (Iran, Islamic Republic of); Rahmani, Ali Akbar [Department of Mining Engineering, Faculty of Engineering and Technology, Imam Khomeini International University, Qazvin (Iran, Islamic Republic of); Khataee, Alireza, E-mail: a_khataee@tabrizu.ac.ir [Research Laboratory of Advanced Water and Wastewater Treatment Processes, Department of Applied Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz (Iran, Islamic Republic of)

    2015-02-01

    Graphical abstract: - Highlights: • Pyrite nanoparticles were successfully produced by planetary ball milling process. • The physical and chemical properties of pyrite nanoparticles were fully examined. • The degradation of AO7 was notably enhanced by pyrite nanoparticles Fenton system. • The influences of basic operational parameters were investigated using CCD. - Abstract: In the present study pyrite nanoparticles were prepared by high energy mechanical ball milling utilizing a planetary ball mill. Various pyrite samples were produced by changing the milling time from 2 h to 6 h, in the constant milling speed of 320 rpm. X-ray diffraction (XRD), scanning electron microscopy (SEM) linked with energy dispersive X-ray (EDX), Fourier transform infrared spectroscopy (FT-IR) analysis and Brunauer–Emmett–Teller (BET) were performed to explain the characteristics of primary (unmilled) and milled pyrite samples. The average particle size distribution of the produced pyrite during 6 h milling was found to be between 20 nm and 100 nm. The catalytic performance of the different pyrite samples was examined in the heterogeneous Fenton process for degradation of C.I. Acid Orange 7 (AO7) solution. Results showed that the decolorization efficiency of AO7 in the presence of 6 h-milled pyrite sample was the highest. The impact of key parameters on the degradation efficiency of AO7 by pyrite nanoparticles catalyzed Fenton process was modeled using central composite design (CCD). Accordingly, the maximum removal efficiency of 96.30% was achieved at initial AO7 concentration of 16 mg/L, H{sub 2}O{sub 2} concentration of 5 mmol/L, catalyst amount of 0.5 g/L and reaction time of 25 min.

  8. Salicylic acid degradation by advanced oxidation processes. Coupling of solar photoelectro-Fenton and solar heterogeneous photocatalysis.

    Science.gov (United States)

    Garza-Campos, Benjamin; Brillas, Enric; Hernández-Ramírez, Aracely; El-Ghenymy, Abdellatif; Guzmán-Mar, Jorge Luis; Ruiz-Ruiz, Edgar J

    2016-12-05

    A 3.0 L solar flow plant with a Pt/air-diffusion (anode/cathode) cell, a solar photoreactor and a photocatalytic photoreactor filled with TiO2-coated glass spheres has been utilized to couple solar photoelectro-Fenton (SPEF) and solar heterogeneous photocatalysis (SPC) for treating a 165mgL(-1) salicylic acid solution of pH 3.0. Organics were destroyed by OH radicals formed on the TiO2 photocatalyst and at the Pt anode during water oxidation and in the bulk from Fenton's reaction between added Fe(2+) and cathodically generated H2O2, along with the photolytic action of sunlight. Poor salicylic acid removal and mineralization were attained using SPC, anodic oxidation with electrogenerated H2O2 (AO-H2O2) and coupled AO-H2O2-SPC. The electro-Fenton process accelerated the substrate decay, but with low mineralization by the formation of byproducts that are hardly destroyed by OH. The mineralization was strongly increased by SPEF due to the photolysis of products by sunlight, being enhanced by coupled SPEF-SPC due to the additional oxidation by OH at the TiO2 surface. The effect of current density on the performance of both processes was examined. The most potent SPEF-SPC process at 150mAcm(-2) yielded 87% mineralization and 13% current efficiency after consuming 6.0AhL(-1). Maleic, fumaric and oxalic acids detected as final carboxylic acids were completely removed by SPEF and SPEF-SPC.

  9. Mineralization of the textile dye acid yellow 42 by solar photoelectro-Fenton in a lab-pilot plant.

    Science.gov (United States)

    Espinoza, Carolina; Romero, Julio; Villegas, Loreto; Cornejo-Ponce, Lorena; Salazar, Ricardo

    2016-12-05

    A complete mineralization of a textile dye widely used in the Chilean textile industry, acid yellow 42 (AY42), was studied. Degradation was carried out in an aqueous solution containing 100mgL(-1) of total organic carbon (TOC) of dye using the advanced solar photoelectro-Fenton (SPEF) process in a lab-scale pilot plant consisting of a filter press cell, which contains a boron doped diamond electrode and an air diffusion cathode (BDD/air-diffusion cell), coupled with a solar photoreactor for treat 8L of wastewater during 270min of electrolysis. The main results obtained during the degradation of the textile dye were that a complete transformation to CO2 depends directly on the applied current density, the concentration of Fe(2+) used as catalyst, and the solar radiation intensity. The elimination of AY42 and its organic intermediates was due to hydroxyl radicals formed at the anode surface from water oxidation and in the bulk from Fenton's reaction between electrogenerated H2O2 and added Fe(2+). The application of solar radiation in the process (SPEF) yield higher current efficiencies and lower energy consumptions than electro-Fenton (EF) and electro-oxidation with electrogenerated H2O2 (E OH2O2) by the additional production of hydroxyl radicals from the photolysis of Fe(III) hydrated species and the photodecomposition of Fe(III) complexes with organic intermediates. Moreover, some products and intermediates formed during mineralization of dye, such as inorganic ions, carboxylic acids and aromatic compounds were determined by photometric and chromatographic methods. An oxidation pathway is proposed for the complete conversion to CO2.

  10. 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.

  11. Enhanced sonochemical degradation of azure B dye by the electroFenton process.

    Science.gov (United States)

    Martínez, Susana Silva; Uribe, Edgar Velasco

    2012-01-01

    The degradation of azure B dye (C15H16ClN3S; AB) has been studied by Fenton, sonolysis and sono-electroFenton processes employing ultrasound at 23 kHz and the electrogeneration of H2O2 at the reticulated vitreous carbon electrode. It was found that the dye degradation followed apparent first-order kinetics in all the degradation processes tested. The rate constant was affected by both the pH of the solution and initial concentration of Fe2+, with the highest degradation obtained at pH between 2.6 and 3. The first-order rate constant decreased in the following order: sono-electroFenton>Fenton>sonolysis. The rate constant for AB degradation by sono-electroFenton is ∼10-fold that of sonolysis and ∼2-fold the one obtained by Fenton under silent conditions. The chemical oxygen demand was abated ∼68% and ∼85% by Fenton and sono-electroFenton respectively, achieving AB concentration removal over 90% with both processes.

  12. 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)

  13. 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.

  14. 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.

  15. 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.

  16. 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).

  17. Advanced treatment of biologically pretreated coal gasification wastewater by a novel integration of heterogeneous Fenton oxidation and biological process.

    Science.gov (United States)

    Xu, Peng; Han, Hongjun; Zhuang, Haifeng; Hou, Baolin; Jia, Shengyong; Xu, Chunyan; Wang, Dexin

    2015-04-01

    Laboratorial scale experiments were conducted in order to investigate a novel system integrating heterogeneous Fenton oxidation (HFO) with anoxic moving bed biofilm reactor (ANMBBR) and biological aerated filter (BAF) process on advanced treatment of biologically pretreated coal gasification wastewater (CGW). The results indicated that HFO with the prepared catalyst (FeOx/SBAC, sewage sludge based activated carbon (SBAC) which loaded Fe oxides) played a key role in eliminating COD and COLOR as well as in improving the biodegradability of raw wastewater. The surface reaction and hydroxyl radicals (OH) oxidation were the mechanisms for FeOx/SBAC catalytic reaction. Compared with ANMBBR-BAF process, the integrated system was more effective in abating COD, BOD5, total phenols (TPs), total nitrogen (TN) and COLOR and could shorten the retention time. Therefore, the integrated system was a promising technology for engineering applications.

  18. 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.

  19. 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.

  20. Low-pressure catalytic wet-air oxidation of a high-strength industrial wastewater using Fenton's reagent.

    Science.gov (United States)

    Biçaksiz, Zeliha; Aytimur, Gülin; Atalay, Süheyda

    2008-06-01

    Wastewater from the Afyon Alkaloids Factory (Afyon, Turkey) was subjected to low-pressure catalytic wet-air oxidation (CWAO) using Fenton's reagent, and the optimal reaction conditions were investigated. The CWAO using Fenton's reagent was applied to the factory effluent, diluted factory effluent, and aerobically pretreated wastewater. To find the optimum quantities of reagents, ferrous iron (Fe(+2))-to-substrate ratios of 1:10, 1:25, and 1:50 and hydrogen peroxide (H2O2)-to-Fe(+2) ratios of 1, 5, and 10 were investigated, and the treatment was carried out at different temperatures. High chemical oxygen demand (COD) removals were obtained at 50 degrees C, with the Fe(+2)-to-substrate ratio range between 1:10 and 1:25. The change in H2O2-to-Fe(+2) ratios did not cause any considerable effect. Also, the percentages of COD removals were nearly the same, so the ratio H2O2:Fe(+2):1 is recommended. Aerobic pretreatment seems to be effective. On the other hand, no enhancement was observed in the case of the diluted wastewater.

  1. In situ anchor of magnetic Fe3O4 nanoparticles onto natural maifanite as efficient heterogeneous Fenton-like catalyst

    Science.gov (United States)

    Zhao, Hang; Weng, Ling; Cui, Wei-Wei; Zhang, Xiao-Rui; Xu, Huan-Yan; Liu, Li-Zhu

    2016-09-01

    In situ anchor of magnetic Fe3O4 nanoparticles (NPs) onto the surface of natural maifanite was realized by chemical oxidation coprecipitation in hot alkaline solution. The Fe3O4/maifanite composites were characterized by XRD, FTIR, SEM, and TEM. These results indicated that polycrystalline Fe3O4 NPs with inverse spinel structure were formed and tightly dispersed on maifanite surface. Based on the measurement of surface Zeta potential of maifanite at different medium pHs, the possible combination mechanism between natural maifanite and Fe3O4 NPs was proposed. Then, the asobtained composites were developed as highly efficient heterogeneous Fenton-like catalyst for the discoloration of an azo dye, Methyl Orange (MO). The comparative tests on MO discoloration in different systems revealed that Fe3O4/maifanite composite exhibited much higher Fenton-like catalytic activity than Fe3O4 NPs and the heterogeneous Fentonlike reaction governed the discoloration of MO. Kinetic results clearly showed that MO discoloration process followed the second-order kinetic model. Fe3O4/maifanite composites exhibited the typical ferromagnetic property detected by VSM and could be easily separated from solution by an external magnetic field.

  2. Effects of operating parameters on advanced oxidation of diuron by the Fenton's reagent: a statistical design approach.

    Science.gov (United States)

    Catalkaya, Ebru Cokay; Kargi, Fikret

    2007-09-01

    Advanced oxidation of diuron in aqueous solution by Fenton's reagent using FeSO(4) as source of Fe(II) was investigated in the absence of light. Effects of operating parameters namely the concentrations of pesticide (diuron), H(2)O(2) and Fe(II) on oxidation of diuron was investigated by using Box-Behnken statistical experiment design and the surface response analysis. Diuron oxidation by the Fenton reagent was evaluated by determining the total organic carbon (TOC), diuron, and adsorbable organic halogen (AOX) removals. Concentration ranges of the reagents resulting in the highest level of diuron oxidation were determined. Diuron removal increased with increasing H(2)O(2) and Fe(II) concentrations up to a certain level. Diuron concentration had a more profound effect than H(2)O(2) and Fe(II) in removal of diuron, TOC and AOX from the aqueous solution. Nearly complete (98.5%) disappearance of diuron was achieved after 15min reaction period. However, only 58% of diuron was mineralized after 240min under optimal operating conditions indicating formation of some intermediate products. Optimal H(2)O(2)/Fe(II)/diuron ratio resulting in the maximum diuron removal (98.5%) was found to be 302/38/20 (mgl(-1)).

  3. Efficient mineralization of the antibiotic trimethoprim by solar assisted photoelectro-Fenton process driven by a photovoltaic cell.

    Science.gov (United States)

    Zhang, Yanyu; Wang, Aimin; Tian, Xiujun; Wen, Zhenjun; Lv, Hanjiao; Li, Desheng; Li, Jiuyi

    2016-11-15

    In this study, a novel self-sustainable solar assisted photoelectro-Fenton (SPEF) system driven by a solar photovoltaic cell was developed for the efficient mineralization of antibiotic trimethoprim (TMP) in water. A comparative degradation of 200mgL(-1) TMP by RuO2/Ti anodic oxidation (AO), anodic oxidation with H2O2 electrogeneration (AO-H2O2), electro-Fenton (EF) and SPEF was investigated. SPEF was proved to exhibit the highest oxidation power, i.e., more than 80% TOC was removed after 360min SPEF treatment of 200mgL(-1) of TMP under optimal conditions at pH 3.0, 1.0mM Fe(2+) and 18mAcm(-2). Influences of current density, pH, initial Fe(2+) and initial TMP concentration on SPEF process were also studied. Ten aromatic intermediates generated from hydroxylation, carbonylation and demethylation reactions were identified using UPLC-QTOF-MS/MS system during the SPEF treatment, together with three carboxylic acids (oxamic, oxalic and formic acids) and two inorganic ions (NH4(+) and NO3(-)) measured. Therefore, a reasonable pathway of TMP degradation in SPEF process was proposed.

  4. Fenton degradation assisted by cyclodextrins of a high molecular weight polycyclic aromatic hydrocarbon benzo[a]pyrene.

    Science.gov (United States)

    Veignie, Etienne; Rafin, Catherine; Landy, David; Fourmentin, Sophie; Surpateanu, Gheorghe

    2009-09-15

    This paper investigates the effect of native beta-cyclodextrin (beta-CD) and its CD derivatives, such as hydroxypropyl-beta-cyclodextrin (HPBCD) and randomly methylated-beta-cyclodextrin (RAMEB), on the solubilization of a high molecular weight polycyclic aromatic hydrocarbon benzo[a]pyrene (BaP) and on its degradation by Fenton's reaction. The results show that BaP apparent solubility was significantly increased in the presence of cyclodextrin (CD) in the following order: beta-CDcyclodextrin to solubilize BaP. In the presence of a radical scavenger (mannitol), BaP Fenton degradation was inhibited with RAMEB but not in the presence of HPCD. Molecular modelisation was used to visualize the steric complementarity of these host-guest systems. No significant difference of encapsulation between the two modified CDs was observed. Nevertheless, the results suggest a probable existence of a ternary complex HPCD-BaP-iron permitting the generation of hydroxyl radicals in close proximity to BaP. On the basis of these results, it appears that HPCD may be useful for developing targeted BaP degradation system.

  5. LiFePO4 microcrystals as an efficient heterogeneous Fenton-like catalyst in degradation of rhodamine 6G.

    Science.gov (United States)

    Li, Zhan Jun; Ali, Ghafar; Kim, Hyun Jin; Yoo, Seong Ho; Cho, Sung Oh

    2014-01-01

    We present a novel heterogeneous Fenton-like catalyst of LiFePO4 (LFP). LFP has been widely used as an electrode material of a lithium ion battery, but we observed that commercial LFP (LFP-C) could act as a good Fenton-like catalyst to decompose rhodamine 6G. The catalytic activity of LFP-C microparticles was much higher than a popular catalyst, magnetite nanoparticles. Furthermore, we found that the catalytic activity of LFP-C could be further increased by increasing the specific surface area. The reaction rate constant of the hydrothermally synthesized LFP microcrystals (LFP-H) is at least 18 times higher than that of magnetite nanoparticles even though the particle size of LFP is far larger than magnetite nanoparticles. The LFP catalysts also exhibited a good recycling behavior and high stability under an oxidizing environment. The effects of the experimental parameters such as the concentration of the catalysts, pH, and the concentration of hydrogen peroxide on the catalytic activity of LFP were also analyzed.

  6. Importance of iron complexation for Fenton-mediated hydroxyl radical production at circumneutral pH

    Directory of Open Access Journals (Sweden)

    Christopher J. Miller

    2016-08-01

    Full Text Available The reaction between Fe(II and H2O2 to yield hydroxyl radicals (HO•, the Fenton reaction, is of interest due to its role in trace metal and natural organic matter biogeochemistry, its utility in water treatment and its role in oxidative cell degradation and associated human disease. There is significant dispute over whether HO•, the most reactive of the so-called reactive oxygen species, is formed in this reaction, particularly under circumneutral conditions relevant to natural systems. In this work we have studied the oxidation kinetics of Fe(II complexed by L = citrate, ethylenediaminetetraacetic acid (EDTA and diethylenetriaminepentaacetic acid (DTPA and also measured HO• production using phthalhydrazide as a probe compound at pH 8.2. It is shown that HO• is the sole product of the Fe(IIL-H2O2 reaction for L = EDTA and DTPA, with kinetic modelling of the full reaction pathway utilized to confirm this finding. Quantitative HO• production also appears likely for L = citrate, although uncertainties with the speciation of Fe(II-citrate complexes as well as difficulties in modelling the oxidation kinetics of these complexes has prevented a definitive conclusion. In the absence of ligands at circumneutral pH, inorganic Fe(II reacts with H2O2 to yield a species other than HO•, contrary to the well-established production of HO• from inorganic Fe(II at low pH. Our results suggest that at high pH Fe(II must be complexed for HO• production to occur.

  7. Application of a hybrid Electrocoagulation-Fenton process in yarn dye wastewater: Kinetic study

    Science.gov (United States)

    Riadi, L.; Sapei, L.; Lidiawati, T.; Agustin, Y. E.

    2016-11-01

    Reactive dyes contain a significant portion of colorants used in yarn dying process and also in textile industry. Since the COD content is usually high in such wastewater,we conducted a hybrid electrocoagulation-fenton method to treat the wastewater. This work describes the application of the hybrid system to the removal of chemical oxygen demand and color from the wastewater in a batch reactor. Having worked with initial pH of 3,0; temperature at 30°C, molar ratio of Fe2+/H2O2 =1/10 and the mol ratio H2O2/COD = 4, we got 88.3% COD conversion and 88.5% color removal. The COD degradation process can be explained in two phases, the first phase is instantaneous reaction and the second phase is first order reaction. The kinetic constant was 0.0053 minute-1 and the rate of COD degradation was 0.0053[COD] mg/L minute.

  8. 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.

  9. Wastewater treatment using hybrid treatment schemes based on cavitation and Fenton chemistry: a review.

    Science.gov (United States)

    Bagal, Manisha V; Gogate, Parag R

    2014-01-01

    Advanced oxidation processes such as cavitation and Fenton chemistry have shown considerable promise for wastewater treatment applications due to the ease of operation and simple reactor design. In this review, hybrid methods based on cavitation coupled with Fenton process for the treatment of wastewater have been discussed. The basics of individual processes (Acoustic cavitation, Hydrodynamic cavitation, Fenton chemistry) have been discussed initially highlighting the need for combined processes. The different types of reactors used for the combined processes have been discussed with some recommendations for large scale operation. The effects of important operating parameters such as solution temperature, initial pH, initial pollutant concentration and Fenton's reagent dosage have been discussed with guidelines for selection of optimum parameters. The optimization of power density is necessary for ultrasonic processes (US) and combined processes (US/Fenton) whereas the inlet pressure needs to be optimized in the case of Hydrodynamic cavitation (HC) based processes. An overview of different pollutants degraded under optimized conditions using HC/Fenton and US/Fenton process with comparison with individual processes have been presented. It has been observed that the main mechanism for the synergy of the combined process depends on the generation of additional hydroxyl radicals and its proper utilization for the degradation of the pollutant, which is strongly dependent on the loading of hydrogen peroxide. Overall, efficient wastewater treatment with high degree of energy efficiency can be achieved using combined process operating under optimized conditions, as compared to the individual process.

  10. Decoloration and mineralization of yeast wastewater by using Ce-Fe/Al2O3 as heterogeneous photo-Fenton catalyst

    Institute of Scientific and Technical Information of China (English)

    WEI Chao-hai; ZHANG Ya-ping; WU Chao-fei; HU Cheng-sheng

    2006-01-01

    Decoloration and mineralization of yeast wastewater were investigated by using Ce-Fe/Al2O3 as a heterogeneous photo-Fenton catalyst in fluidized bed reactor in order to solve the problem of yeast wastewater discharge.The experimental results were assessed in terms of total organic carbon(TOC) reduction. The operational and reaction conditions affecting the efficiencies of TOC removal such as initial pH value, H2O2 concentration, catalyst loading and UV power were studied. The results show that TOC is reduced from 347.6 mg/L to 10.8 mg/L, color is changed from 500 units to 0 under the conditions as follows: initial pH value 6. 0, H2O2 concentration of 1.000 g/L,catalyst loading of 5 g/L, reaction duration of 120 min and reaction temperature of 30 ℃. The irradiated Ce-Fe/Al2O3 catalyst was complexed with 1,10-phenanthroline and then it was subjected to Fourier transform infrared spectroscopy and diffuse reflectance spectroscopy to confirm the formation of Fe( Ⅱ ) in the solid state. Heterogeneous photo-Fenton reaction proves to be effective for the treatment of yeast wastewater.

  11. UV/Fenton/杂多酸体系对染料曙红Y的光解作用研究%Study on UV/Fenton/Heteropoly Acid System Photolysis of Dye Eosin Y

    Institute of Scientific and Technical Information of China (English)

    高航; 马威; 李海霞; 高梅; 李松田

    2012-01-01

    In order to improve oxidation efficiency of Fenton reaction,heteropoly acid was chosen as activator.A new photocatalysis system was established.In photochemical reactor,uv lamp was used as light sources,phosphotungstic acid as photocatalysis additives,UV/Fenton/heteropoly acid system effect to photocatalysis degradation on eosin Y simulative dyeing was studied.Heteropoly acid photocatalysis degradation mechanism to dye,factors that could affect photocatalysis degradation rate of dye,ways to improve photocatalysis degradation efficiency to dye were preliminary studied.Experiments results showed that: H2O2 addition amount to the solution,Fe^2+ concentration,pH value of the solution could affect photocatalysis degradation result.From the experiments,optimum reaction conditions were: pH value was 5-6,30% H2O2 addition amount was 2 mL,FeSO4 dose was 0.02 g/L.%为改善Fenton反应的氧化效率,选择杂多酸为活化剂,建立了一种新的光催化体系。在光化学反应器中,以紫外灯为光源,以磷钨酸为光催化助剂,研究了UV/Fenton/杂多酸体系对曙红Y模拟染料废水的光催化降解的影响,并就杂多酸辅助光催化降解染料的机理,影响染料光催化降解速率的因素,提高染料光催化降解效率的途径进行了初步探讨。结果表明,溶液中H2O2投加量、Fe^2+浓度、溶液pH值是影响催化光解效果的重要因素。实验得出反应的适宜条件是:pH为5~6,30%H2O2的投加量为2 mL,FeSO4的剂量约为0.02 g/L。

  12. 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.

  13. 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.

  14. Degradation kinetics and mechanisms of phenol in photo-Fenton process

    Institute of Scientific and Technical Information of China (English)

    何锋; 雷乐成

    2004-01-01

    Phenol degradation in photochemically enhanced Fenton process was investigated in this work. UV-VIS spectra of phenol degradation showed the difference between photo-Fenton process and UV/H2O2, which is a typical hydroxyl radical process. A possible pathway diagram for phenol degradation in photo-Fenton process was proposed, and a mathematical model for chemical oxygen demand (COD) removal was developed. Operating parameters such as dosage of H2O2 and ferrous ions, pH, suitable carrier gas were found to impact the removal of COD significantly. The results and analysis of kinetic parameters calculated from the kinetic model showed that complex degradation of phenol was the main pathway for removal of COD; while hydroxyl radicals acted weakly in the photo-Fenton degradation of phenol.

  15. Fenton- and Persulfate-driven Regeneration of Contaminant-spent Granular Activated Carbon

    Science.gov (United States)

    Fenton- or persulfate-driven chemical oxidation regeneration of spent granular activated carbon (GAC) involves the combined, synergistic use of two treatment technologies: adsorption of organic chemicals onto GAC and chemical oxidation regeneration of the spent-GAC. Environmental...

  16. Nanoscale zero-valent iron incorporated with nanomagnetic diatomite for catalytic degradation of methylene blue in heterogeneous Fenton system.

    Science.gov (United States)

    Zha, Yiming; Zhou, Ziqing; He, Haibo; Wang, Tianlin; Luo, Liqiang

    2016-01-01

    Nanoscale zero-valent iron (nZVI) incorporated with nanomagnetic diatomite (DE) composite material was prepared for catalytic degradation of methylene blue (MB) in heterogeneous Fenton system. The material was constructed by two facile steps: Fe3O4 magnetic nanoparticles were supported on DE by chemical co-precipitation method, after which nZVI was incorporated into magnetic DE by liquid-phase chemical reduction strategy. The as-prepared catalyst was characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, magnetic properties measurement and nitrogen adsorption-desorption isotherm measurement. The novel nZVI@Fe3O4-diatomite nanocomposites showed a distinct catalytic activity and a desirable effect for degradation of MB. MB could be completely decolorized within 8 min and the removal efficiency of total organic carbon could reach to 90% after reaction for 1 h.

  17. 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.

  18. Tracer experiment results during the Long-Term Flow Test of the Fenton Hill reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, N.E.V. (CSM Associates, Rosemanowes, Penryn, Cornwall (United Kingdom)); Robinson, B.A.; Counce, D.A. (Los Alamos National Lab., NM (United States))

    1993-01-01

    Three chemical tracer experiments and one extended injection of fluid low in concentration of dissolved species have been carried out during the Long Term Flow Test (LTFT) of the Fenton Hill Hot Dry Rock (HDR) reservoir. The tracer tests,results illustrate the dynamic nature of the flow system, with more fluid traveling through longer residence time paths as heat is extracted. The total fracture volumes calculated from these tests allow us to determine the fate of unrecovered injection fluid, examine the pressure-dependence of fracture volume, and, through a comparison to the hydraulic performance, postulate a model for the nature of the pressure drops through the system. The Fresh Water Flush (FWF) test showed that while no dissolved specie behavior is truly conservative (no sources or sinks), several breakthrough curves are well explained with a pore fluid displacement model. Other dissolved components are clearly influenced by dissolution or precipitation reactions. Finally, the transient response of the chemistry during the FWF to an increase in production well pressure showed that some fractures connected to the production well preferentially open when pressure is raised.

  19. 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 sucrose in all reactions. The optimal values of the process parameters for a 200 mg/L HCA mixture in water (pH 4.73, 25.15 °C) and sucrose solution (13 mass %, pH 5.39, 35.98 °C) were 77% and 57%, respectively. Regression 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.

  20. 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 (Pphoto-Fenton process decreases the presence of PCT, oxidative stress, genotoxic damage and LC50 in Hyalella azteca.

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

    OpenAIRE

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

    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...

  2. Chronic transscaphoid, transcapitate perilunate fracture dislocation of the wrist: Fenton's syndrome.

    Science.gov (United States)

    Marcuzzi, A; Ozben, H; Russomando, A; Petit, A

    2013-04-01

    The authors report about chronic Fenton's syndrome. This rare injury of the wrist is characterized by scapho-capitate fracture accompanied by 180° rotation of the head of capitate and associated perilunate dislocation. Two patients suffering from chronic Fenton's syndrome were treated with pyrocarbon capitate resurfacing prosthesis. Patients were evaluated according to the wrist range of motion, Mayo modified wrist and DASH scores. In conclusion, prosthetic surgery may achieve satisfactory results for this rare and diagnostically challenging syndrome.

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

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Leandro G.; Goes, Marcos M.; Marumo, Julio T., E-mail: jtmarumo@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    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 CaCO{sub 3} as a white precipitate resulting from the reaction between the Ca(OH){sub 2} and the CO{sub 2} 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)

  4. Degradation of Sunset Yellow FCF using copper loaded bentonite and H2O2 as photo-Fenton like reagent

    Directory of Open Access Journals (Sweden)

    Kiran Chanderia

    2017-02-01

    Full Text Available In the present work, photo-Fenton degradation of Sunset Yellow FCF under visible light was carried out by using copper loaded bentonite and hydrogen peroxide. The photocatalyst was prepared by loading copper ions on bentonite by wet impregnation method. The rate of photocatalytic degradation of dye was measured spectrophotometrically by measuring absorbance of the reaction mixture at regular time intervals. The effect of various parameters such as pH, concentration of dye, amount of photocatalyst, amount of H2O2 and light intensity on the reaction rate has also been studied. Characterization of photocatalyst has been done by IR spectroscopy, scanning electron microscopy and X-ray diffraction. The Chemical Oxygen Demand (COD of the reaction mixture has been determined before and after treatment. A tentative mechanism involving ·≡OH radical as an oxidant for degradation of dye has also been proposed. Involvement of ·≡OH radicals as an active oxidizing agent has been confirmed by using isopropanol and butylated hydroxy toluene (BHT as radical scavengers. It has been observed that the rate of reaction is drastically reduced in the presence of these scavengers. The rate of reaction is much retarded by using BHT as compared with isopropanol.

  5. Efficient photo-assisted Fenton oxidation treatment of multi-walled carbon nanotubes

    Institute of Scientific and Technical Information of China (English)

    FAN CaiLing; LI Wei; LI Xin; ZHAO ShiJu; ZHANG Ling; MO YuJun; CHENG RongMing

    2007-01-01

    In this paper, a new and efficient way to oxidize and functionalize the multi-walled carbon nanotubes (MWNTs) has been developed by using a combination of ultraviolet (UV) irradiation and Fenton oxidation process, namely UV/Fenton oxidation treatment. Comparing with conventionally individual Fenton oxidation treatment of MWNTs, UV/Fenton combined treatment improved the etching rates and efficiencies and hence reduced the time for surface modification of MWNTs, which was proved to be an effective method in etching and functionalizing CNTs. The formation of new functional groups, structural changes and thermal stability during oxidation period were characterized by Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy and could be clarified by thermogravimetric analysis (TGA), which showed that it was under UV irradiation conditions that MWNTs could be rapidly functionalized with hydroxyl, carbonyl and carboxyl groups in the presence of Fenton reagents, originating from the increase in the gross HO·concentration and the existent synergetic effect when using UV irradiation combing with Fenton oxidation process. Introduction of such new oxygen-containing functional groups was attributed to attacks of HO·on defect sites and unsaturated bonds of C=C in the MWNTs sample, which should play an important role in accounting for the FTIR and Raman spectral changes.

  6. NATURAL IRON OXIDE AS A HETEROGENEOUS PHOTO-FENTON-LIKE CATALYST FOR THE DEGRADATION OF 1-NAPHTHOL UNDER ARTIFICIAL AND SOLAR LIGHT

    Directory of Open Access Journals (Sweden)

    L MAMMERI

    2014-07-01

    Full Text Available A heterogeneous photo-Fenton-like degradation process of 1-naphthol (1-NP promoted by natural iron oxide (NIO in the presence of H2O2 was studied under artificial (365 nm and solar irradiation. This is an important reaction for the environment since both H2O2 and iron oxides are common constituents of natural waters. Furthermore, iron oxides function as catalysts in chemical oxidation processes used with H2O2 for treatment of contaminated waters. The NIO used in this study was characterized by X-ray diffraction (XRD, X-ray fluorescence and Brunauer–Emmett–Teller (BET methods. The results show that the NIO is a composite material that contains predominantly crystalline hematite particales (Fe2O3. The Fe2O3 in NIO was able to initiate the Fenton-like and photo-Fenton-like reactions. The effects of initial pH, catalyst dosage, H2O2 concentration and the wavelength of the light source (UV and solar on the photodegradation of 1-NP were investigated. The optimal content of the NIO was 1 g L-1 and the optimal H2O2 concentration was 10 mM. The degradation could occur efficiently over a wide pH range of 3-8.3. Furthermore, an important effect of light was observed. The photo-oxidation of 1-NP in NIO-H2O2 system under solar light was significantly accelerated in comparison with artificial irradiation at 365 nm.

  7. 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.

  8. 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.

  9. Electro-Fenton pretreatment for the improvement of tylosin biodegradability.

    Science.gov (United States)

    Ferrag-Siagh, Fatiha; Fourcade, Florence; Soutrel, Isabelle; Aït-Amar, Hamid; Djelal, Hayet; Amrane, Abdeltif

    2014-01-01

    The feasibility of an electro-Fenton process to treat tylosin (TYL), a non-biodegradable antibiotic, was examined in a discontinuous electrochemical cell with divided cathodic and anodic compartments. Only 15 min electrolysis was needed for total tylosin degradation using a carbon felt cathode and a platinum anode; while 6 h electrolysis was needed to achieve high oxidation and mineralization yields, 96 and 88 % respectively. Biodegradability improvement was shown since BOD₅/COD increased from 0 initially to 0.6 after 6 h electrolysis (for 100 mg L(-1) initial TYL). With the aim of combining electro-Fenton with a biological treatment, an oxidation time in the range 2 to 4 h has been however considered. Results of AOS (average oxidation state) and COD/TOC suggested that the pretreatment could be stopped after 2 h rather than 4 h; while in the same time, the increase of biodegradability between 2 and 4 h suggested that this latter duration seemed more appropriate. In order to conclude, biological cultures have been therefore carried out for various electrolysis times. TYL solutions electrolyzed during 2 and 4 h were then treated with activated sludge during 25 days, showing 57 and 67% total organic carbon (TOC) removal, respectively, namely 77 and 88% overall TOC removal if both processes were considered. Activated sludge cultures appeared, therefore, in agreement with the assessment made from the analysis of physico-chemical parameters (AOS and COD/TOC), since the gain in terms of mineralization expected from increasing electrolysis duration appeared too low to balance the additional energy consumption.

  10. 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.

  11. Fuzzy-logic modeling of Fenton's strong chemical oxidation process treating three types of landfill leachates.

    Science.gov (United States)

    Sari, Hanife; Yetilmezsoy, Kaan; Ilhan, Fatih; Yazici, Senem; Kurt, Ugur; Apaydin, Omer

    2013-06-01

    Three multiple input and multiple output-type fuzzy-logic-based models were developed as an artificial intelligence-based approach to model a novel integrated process (UF-IER-EDBM-FO) consisted of ultrafiltration (UF), ion exchange resins (IER), electrodialysis with bipolar membrane (EDBM), and Fenton's oxidation (FO) units treating young, middle-aged, and stabilized landfill leachates. The FO unit was considered as the key process for implementation of the proposed modeling scheme. Four input components such as H(2)O(2)/chemical oxygen demand ratio, H(2)O(2)/Fe(2+) ratio, reaction pH, and reaction time were fuzzified in a Mamdani-type fuzzy inference system to predict the removal efficiencies of chemical oxygen demand, total organic carbon, color, and ammonia nitrogen. A total of 200 rules in the IF-THEN format were established within the framework of a graphical user interface for each fuzzy-logic model. The product (prod) and the center of gravity (centroid) methods were performed as the inference operator and defuzzification methods, respectively, for the proposed prognostic models. Fuzzy-logic predicted results were compared to the outputs of multiple regression models by means of various descriptive statistical indicators, and the proposed methodology was tested against the experimental data. The testing results clearly revealed that the proposed prognostic models showed a superior predictive performance with very high determination coefficients (R (2)) between 0.930 and 0.991. This study indicated a simple means of modeling and potential of a knowledge-based approach for capturing complicated inter-relationships in a highly non-linear problem. Clearly, it was shown that the proposed prognostic models provided a well-suited and cost-effective method to predict removal efficiencies of wastewater parameters prior to discharge to receiving streams.

  12. UV light photo-Fenton degradation of polyphenols in oolong tea manufacturing wastewater.

    Science.gov (United States)

    Sabaikai, Waraluk; Sekine, Makoto; Tokumura, Masahiro; Kawase, Yoshinori

    2014-01-01

    The UV light photo-Fenton degradation of oolong tea polyphenols in tea manufacturing effluent that color the wastewater to a dark brown has been examined. In order to elucidate the photo-Fenton degradation mechanism of oolong tea polyphenols and find the optimal dosages of the Fenton reagents, systematic study has been conducted. For the UV light photo-Fenton degradation of oolong tea effluent being 70 mg-(polyphenol) L(-1), the optimum dosages of Fenton reagents were found to be 20 mgL(-1) of total Fe and 500 mgL(-1) of H2O2. The polyphenol degradation could be divided into two stages. The polyphenols concentration rapidly decreased to around 30% of the initial concentration within 2 min and the degradation rate significantly slowed down in the subsequent stage. After 60 min of UV light irradiation, 97% polyphenol removal was obtained. The initial quick degradation of oolong tea polyphenols suggests that hydroxyl radical generated by the photo-Fenton process might preferentially attack polyphenols having high antioxidant activity by scavenging hydroxyl radicals. Almost complete decolorization of the oolong tea effluent was achieved after 80 min. About 96% mineralization of 63 mgL(-1) TOC loading was achieved within 60 min and then further mineralization was rather slow. The complete COD removal of 239 mgL(-1) COD loading was obtained after 100 min. The present results indicate that the UV light photo-Fenton degradation process can treat tea manufacturing wastewaters very effectively.

  13. 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.

  14. Investigation on pretreatment of centrifugal mother liquid produced in the production of polyvinyl chloride by air-Fenton technique.

    Science.gov (United States)

    Sun, Yingying; Hua, Xiuyi; Ge, Rui; Guo, Aitong; Guo, Zhiyong; Dong, Deming; Sun, Wentian

    2013-08-01

    Centrifugal mother liquid (CML) is one of the main sources of wastewater produced during the production of polyvinyl chloride in chlor-alkali industry. CML is a typical poorly biodegradable organic wastewater, containing many kinds of refractory pollutants. Specifically, it contains dissolved refractory polymers, especially polyvinyl alcohol (PVA), which can pass though the biotreatment processes and clog the membranes used for further treatment. In this study, to ensure the CML applicable to biotreatment and membrane treatment, a novel efficient and mild technique, air-Fenton treatment, was employed as a pretreatment technique to improve biodegradability of the CML and to break down the polymers in the CML. Firstly, the technique was optimized for the CML treatment by optimizing the main parameters, including the dosage of ferrous sulfate, initial pH of the wastewater, [H2O2]/[Fe(2+)], aeration rate, reaction time, and temperature, based on removal efficiency of COD and PVA from the CML. Then, the optimized technique was tested and evaluated. The results indicated that under the optimized conditions, the air-Fenton treatment could remove 66, 98, and 55 % of the COD, PVA, and TOC, respectively, from the CML. After the treatment, biodegradability of the wastewater increased significantly (BOD/COD increased from 0.31 to 0.68), and almost all of the PVA polymers were removed or broken down. Meanwhile, concentration of the remaining iron ions, which were added during the treatment, was also quite low (only 2.9 mg/L). Furthermore, most of the suspended materials and ammonia nitrogen, and some of the phosphorus in the wastewater were removed simultaneously.

  15. The use of Fenton's reagent in treating waste waters from the table olive producing industry; Aplicacion del reactivo de Fenton para la depuracion de las aguas residuales de la industria productora de aceituna de mesa

    Energy Technology Data Exchange (ETDEWEB)

    Beltran de Heredia, J.; Dominguez, J. R.

    2001-07-01

    A study was made of the chemical oxidation by means of Fenton's reagent (H{sub 2}O{sub 2}/Fe''24) on the lye used in pickling black olives. The aim of this process is to eliminate the organic materials from the waste water. It was monitored by tracking several overall reaction parameters such as Chemical Oxygen Demand (COD), total polyphenols, the aromaticity of the sample and the concentration of hydrogen peroxide in the reactor. The elimination rate obtained for the chemical oxygen demand after 90 minutes of reaction varied between 28 and 73% (depending on the conditions of the operation). Polyphenols were reduced by between 26 and 90%, while aromaticity was reduced by between 36 and 94%. In addition, the stechiometric coefficient of the reaction was determined for different operating conditions and was found to range from 0.11 to 1.82 g COD/gH{sub 2}O{sub 2}. An analysis of the results shows that the higher the dose of hydrogen peroxide, the greater the reduction of COD, but also the lower the stechiometric coefficient and, therefore, the less efficient the use made of the hydrogen peroxide. (Author) 19 refs.

  16. Novel low-cost Fenton-like layered Fe-titanate catalyst: preparation, characterization and application for degradation of organic colorants.

    Science.gov (United States)

    Chen, Yongzhou; Li, Nian; Zhang, Ye; Zhang, Lide

    2014-05-15

    Novel low-cost layered Fe-titanate catalyst for photo-Fenton degradation of organic contaminants was successfully developed by ion exchange of Fe(3+) with Na(+) layered nano Na-titanates which was prepared by alkali hydrothermal method. The as prepared materials were characterized by powder X-ray diffraction analysis (XRD), field emission scanning electron microscopy (FESEM) and energy-dispersive X-ray spectrometer (EDX). The catalytic activity of the Fe-titanate catalyst was evaluated by the decolorization of three different dyes (rhodamine 6G (R6G), methyl blue (MB), and methyl orange (MO)) under UV irradiation at room temperature. Effect of several important factors such as Fe loading in the catalyst, initial solution pH, catalyst dosage, H2O2 amount, and reaction time was systematically studied. It was found that the decolorization was very efficient for all three dyes. The efficiency reached 98% for R6G, 98.5% for MB, and 97% for MO, respectively, under optimal conditions. The oxidation process was quick, and only 15 min is needed for all three dyes. Moreover, the Fe-titanate catalyst could be used in a wider and near neutral pH range compared with classic Fenton systems which need to be operated at around pH 3.0. Kinetic analysis results showed that the oxidation kinetics was accurately represented by pseudo-first-order model. More importantly, the catalyst was very stable and could be reused for at least four cycles when operated under near neutral pH. The Fe leaching from the catalyst measured was almost negligible, which not only demonstrated the stability of the catalyst, but also avoided the formation of secondary Fe pollution. Therefore, the reported Fe-titanates are promising nanomaterials which can be used as Fenton like catalyst for the degradation of organic contaminant in wastewater.

  17. Surface structure and properties of biomedical NiTi shape memory alloy after Fenton's oxidation.

    Science.gov (United States)

    Chu, C L; Hu, T; Wu, S L; Dong, Y S; Yin, L H; Pu, Y P; Lin, P H; Chung, C Y; Yeung, K W K; Chu, Paul K

    2007-09-01

    Fenton's oxidation is traditionally used to remove inorganic and organic pollutants from water in waster water treatment. It is an advanced oxidation process in which H2O2 is catalytically decomposed by ferrous irons into hydroxyl radicals (*OH) which have a higher oxidation potential (2.8V) than H2O2. In the work reported here, we for the first time use Fenton's oxidation to modify the surface of biomedical NiTi shape memory alloy (SMA). The influences of Fenton's oxidation on the surface microstructure, blood compatibility, leaching of harmful Ni ions and corrosion resistance in simulated body fluids is assessed using scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, inductively coupled plasma mass spectrometry, electrochemical tests, hemolysis analysis and the blood platelet adhesion test. The mechanical stability of the surface titania film produced by Fenton's oxidation as well as their effects on the shape memory behavior of the SMA are studied by bending tests. Our results show that Fenton's oxidation produces a novel nanostructured titania gel film with a graded structure on the NiTi substrate without an intermediate Ni-rich layer that is typical of high-temperature oxidation. Moreover, there is a clear Ni-free zone near the top surface of the titania film. The surface structural changes introduced by Fenton's oxidation improve the electrochemical corrosion resistance and mitigate Ni release. The latter effects are comparable to those observed after oxygen plasma immersion ion implantation reported previously and better than those of high-temperature oxidation. Aging in boiling water improves the crystallinity of the titania film and further reduces Ni leaching. Blood platelet adhesion is remarkably reduced after Fenton's oxidation, suggesting that the treated SMA has improved thrombo resistance. Enhancement of blood compatibility is believed to stem from the improved hemolysis resistance, the surface wettability and the

  18. Elimination of radiocontrast agent diatrizoic acid by photo-Fenton process and enhanced treatment by coupling with electro-Fenton process.

    Science.gov (United States)

    Bocos, Elvira; Oturan, Nihal; Pazos, Marta; Sanromán, M Ángeles; Oturan, Mehmet A

    2016-10-01

    The removal of radiocontrast agent diatrizoic acid (DIA) from water was performed using photo-Fenton (PF) process. First, the effect of H2O2 dosage on mineralization efficiency was determined using ultraviolet (UV) irradiation. The system reached a maximum mineralization degree of 60 % total organic carbon (TOC) removal at 4 h with 20 mM initial H2O2 concentration while further concentration values led to a decrease in TOC abatement efficiency. Then, the effect of different concentrations of Fenton's reagents was studied for homogeneous Fenton process. Obtained results revealed that 0.25 mM Fe(3+) and 20 mM H2O2 were the best conditions, achieving 80 % TOC removal efficiency at 4 h treatment. Furthermore, heterogeneous PF treatment was developed using iron-activated carbon as catalyst. It was demonstrated that this catalyst is a promising option, reaching 67 % of TOC removal within 4 h treatment without formation of iron leachate in the medium. In addition, two strategies of enhancement for process efficiency are proposed: coupling of PF with electro-Fenton (EF) process in two ways: photoelectro-Fenton (PEF) or PF followed by EF (PF-EF) treatments, achieving in both cases the complete mineralization of DIA solution within only 2 h. Finally, the Microtox tests revealed the formation of more toxic compounds than the initial DIA during PF process, while, it was possible to reach total mineralization by both proposed alternatives (PEF or PF-EF) and thus to remove the toxicity of DIA solution.

  19. Fenton/BAF组合工艺处理全棉机织布印染废水研究%Fenton Oxidation/BAF Process for Advanced Treatment of Wastewater from Dyeing and Finishing of Cotton Woven Fabrics

    Institute of Scientific and Technical Information of China (English)

    文淦斌; 黄瑞敏; 黄春梅; 王君

    2011-01-01

    The dyeing and finishing processes of cotton woven fabrics need a lot of sizing agents toimprove the smoothness and wear resistance of the fabrics, thus the discharged wastewater often contains a lot of desizing wastewater, which has high concentration of COD, strong alkalinity and poor biodegradability. The biodegradability is difficult to be improved using conventional coagulation sedimentation/anaerobic/aerobic process, and the effluent COD and color are difficult to meet the standards. According to the characteristics above, the combined process of Fenton oxidation and biological aerated filter (BAF) was used for the advanced treatment. The results of the pilot study show that under the conditions of initial pH of 4, H2O2 dosage of 150 mg/L, Fe2+/H2O2 ratio of 1 and reaction time of 60 min in Fenton oxidation process, COD and color of the wastewater are reduced from 400 mg/L to 125 mg/L with the removal rate of 68.75% and from 200 times to less than 25 times respectively. After the Fenton oxidation,the B/C ratio is increased from 0.08 to 0.34, and the biodegradability is significantly improved. Under the condition of HRT of 2.5 h, COD in the effluent from BAF is 74.5 mg/L, with the removal rate of 40.4%. After treatment by the combined process, the removal rate of COD is more than 80% , and the color is less than 25 times, with good treatment efficiency.%全棉机织布染色加工需使用大量浆料助剂进行上浆处理以提高织物的光滑度及耐磨性,因而排放的废水中往往含有大量的退浆废水,其COD浓度高、碱度强、可生化性差,经常规的混凝沉淀/厌氧/好氧组合工艺处理后,可生化性难以改善,出水COD、色度值难以达标.采用Fen-ton/曝气生物滤池(BAF)组合工艺对其进行深度处理,中试结果表明,在Fenton工艺的初始pH值=4、H2O2投加量=150 mg/L、Fe2+/H2O2值=1、反应时间为60 min的条件下,COD由原来的400mg/L降低至125 mg/L,去除率达68.75%,色度由200

  20. Combined effects of Fenton peroxidation and CaO conditioning on sewage sludge thermal drying.

    Science.gov (United States)

    Liu, Huan; Liu, Peng; Hu, Hongyun; Zhang, Qiang; Wu, Zhenyu; Yang, Jiakuan; Yao, Hong

    2014-12-01

    Joint application of Fenton's reagent and CaO can dramatically enhance sludge dewaterability, thus are also likely to affect subsequent thermal drying process. This study investigated the synergistic effects of the two conditioners on the thermal drying behavior of sewage sludge and the emission characteristics of main sulfur-/nitrogen-containing gases. According to the results, Fenton peroxidation combined with CaO conditioning efficiently promoted sludge heat transfer, reduced the amounts of both free and bound water, and created porous structure in solids to provide evaporation channels, thus producing significant positive effects on sludge drying performance. In this case, the required time for drying was shortened to one-third. Additionally, joint usage of Fenton's reagent and CaO did not increase the losses of organic matter during sludge drying process. Meanwhile, they facilitated the formation of sulfate and sulfonic acid/sulfone, leading to sulfur retention in dried sludge. Both of Fenton peroxidation and CaO conditioning promoted the oxidation, decomposition, and/or dissolution of protein and inorganic nitrogen in sludge pre-treatment. As a consequence, the emissions of sulfurous and nitrogenous gases from dewatered sludge drying were greatly suppressed. These indicate that combining Fenton peroxidation with CaO conditioning is a promising strategy to improve drying efficiency of sewage sludge and to control sulfur and nitrogen contaminants during sludge thermal drying process.

  1. 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.

  2. 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…

  3. Roles of TaON and Ta{sub 3}N{sub 5} in the visible-Fenton-like degradation of atrazine

    Energy Technology Data Exchange (ETDEWEB)

    Du, Yingxun, E-mail: yxdu@niglas.ac.cn; Zhao, Lu; Zhang, Yuanyuan

    2014-02-01

    Graphical abstract: - Highlights: • TaON exhibited higher photocatalytic activity than Ta{sub 3}N{sub 5}. • e{sub CB} is captured by either Fe{sup 3+} or H{sub 2}O{sub 2} and h{sub VB} could not oxidize atrazine. • ·OH, from the reduction of H{sub 2}O{sub 2} by Fe{sup 2+} or by e{sub CB}, is the active species. • By capturing e{sub CB}, H{sub 2}O{sub 2} was preferred to be reduced to H{sub 2}O than to ·OH. • TaON showed the higher separation efficiency of electrons and holes than Ta{sub 3}N{sub 5}. - Abstract: In this study, the roles of TaON and Ta{sub 3}N{sub 5} in the degradation of atrazine by the visible-Fenton-like system were examined in detail. The TaON and Ta{sub 3}N{sub 5} samples prepared by the nitridation of Ta{sub 2}O{sub 5} and characterized by XRD, DRS, BET and PL analyses. The results showed that the TaON sample had weaker absorption in the visible region but higher specific surface area than the Ta{sub 3}N{sub 5} sample. The degradation rate of atrazine in visible-TaON-Fenton-like system was 2.64 times than that in visible-Ta{sub 3}N{sub 5}-Fenton-like system. Both Fe{sup 2+} and H{sub 2}O{sub 2} could be reduced by e{sub CB} (electrons in the conduction band) in TaON or Ta{sub 3}N{sub 5}, while atrazine could not be oxidized by h{sub VB} (holes in the valance band). ·OH is the active species for the degradation of atrazine in visible-TaON/Ta{sub 3}N{sub 5}-Fenton-like systems. Majority of ·OH originated from Fenton reaction. After Fe{sup 3+} was reduced by e{sub CB} to Fe{sup 2+}, Fe{sup 2+} reacted quickly with H{sub 2}O{sub 2} to generate ·OH. In addition, by capturing e{sub CB}, a little of H{sub 2}O{sub 2} was reduced to yield ·OH, which contributed a small fraction of atrazine degradation. Based on the experimental results, the roles of TaON and Ta{sub 3}N{sub 5} in the visible-Fenton-like system were proposed. And the higher photocatalytic activity of TaON than Ta{sub 3}N{sub 5} was suggested to be due to the higher

  4. Quantum efficiencies of the photo-Fenton degradation of atrazine in water.

    Science.gov (United States)

    Benzaquén, T B; Isla, M A; Alfano, O M

    2012-01-01

    An experimental work in a well-stirred batch recycling reactor for the photo-Fenton degradation of atrazine in water is presented. A study of the quantum efficiency is performed to assess the effectiveness of the photo-Fenton process on the atrazine degradation and total organic carbon (TOC) mineralization. Apparent and absolute quantum efficiencies of degradation and mineralization of an atrazine-based commercial herbicide are determined under different experimental conditions. Higher apparent efficiencies were found for both atrazine degradation and TOC mineralization when the ferric ion and hydrogen peroxide concentrations are increased. Because of the well known stability of the triazine ring, atrazine was not completely mineralized by the photo-Fenton process. However, a TOC reduction of 40% was achieved, being 62.5% of the maximum value that can be reached.

  5. 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.

  6. Sequential treatment of olive oil mill wastewater with adsorption and biological and photo-Fenton oxidation.

    Science.gov (United States)

    Aytar, Pınar; Gedikli, Serap; Sam, Mesut; Farizoğlu, Burhanettin; Çabuk, Ahmet

    2013-05-01

    Olive oil mill wastewater (OMWW), a recalcitrant pollutant, has features including high phenolic content and dark color; thereby, several chemical or physical treatments or biological processes were not able to remediate it. In this study, the treatment efficiencies of three treatments, including adsorption, biological application, and photo-Fenton oxidation were sequentially evaluated for OMWW. Adsorption, biological treatment, and photo-Fenton caused decreasing phenolic contents of 48.69 %, 59.40 %, and 95 %, respectively. However, after three sequential treatments were performed, higher reduction percentages in phenolic (total 99 %) and organic contents (90 %) were observed. Although the studied fungus has not induced significant color reduction, photo-Fenton oxidation was considered to be an attractive solution, especially for color reduction. Besides, toxicity of OMWW treatment was significantly reduced.

  7. 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

    products. For this purpose, BPA was subjected to Fenton treatment in the growth medium of the test organisms employed as well as in real lake water. Treatment results indicated that BPA removals were fast and complete within less than a minute, whereas total organic carbon (TOC) removals were rather......Battery tests serve as integral tools to decide whether a treatment process is ecotoxicologically safe or not. In the present study, a battery of toxicity tests was employed to elucidate the toxicity of the potential endocrine-disrupting pollutant bisphenol A (BPA) and its advanced oxidation...... 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...

  8. Treatment of TFT-LCD wastewater containing ethanolamine by fluidized-bed Fenton technology.

    Science.gov (United States)

    Anotai, Jin; Chen, Chia-Min; Bellotindos, Luzvisminda M; Lu, Ming-Chun

    2012-06-01

    The objectives of this study are: (1) to determine the effect of pH, initial concentration of Fe(2+) and H(2)O(2) dosage on the removal efficiency of MEA by fluidized-bed Fenton process and Fenton process, (2) to determine the optimal conditions for the degradation of ethanolamine from TFT-LCD wastewater by fluidized-bed Fenton process. In the design of experiment, the Box-Behnken design was used to optimize the operating conditions. A removal efficiency of 98.9% for 5mM MEA was achieved after 2h under optimal conditions of pH3, [Fe(2+)]=5mM and [H(2)O(2)]=60mM.

  9. Biomimetic Fenton-catalyzed lignin depolymerization to high-value aromatics and dicarboxylic acids.

    Science.gov (United States)

    Zeng, Jijiao; Yoo, Chang Geun; Wang, Fei; Pan, Xuejun; Vermerris, Wilfred; Tong, Zhaohui

    2015-03-01

    By mimicking natural lignin degradation systems, the Fenton catalyst (Fe(3+), H2O2) can effectively facilitate lignin depolymerization in supercritical ethanol (7 MPa, 250 °C) to give organic oils that consist of mono- and oligomeric aromatics, phenols, dicarboxylic acids, and their derivatives in yields up to (66.0±8.5) %. The thermal properties, functional groups, and surface chemistry of lignin before and after Fenton treatment were examined by thermogravimetric analysis, pyrolysis-gas chromatography-mass spectrometry, (31)P NMR spectroscopy, and X-ray photoelectron spectroscopy. The results suggest that the Fenton catalyst facilitates lignin depolymerization through cleavage of β-ether bonds between lignin residues. The formation of a lignin-iron chelating complex effectively depresses lignin recondensation; thus minimizing charcoal formation and enhancing the yield of liquid products.

  10. New Porphyrin/Fe-Loaded TiO2 Composites as Heterogeneous Photo-Fenton Catalysts for the Efficient Degradation of 4-Nitrophenol

    Directory of Open Access Journals (Sweden)

    Giuseppe Mele

    2013-01-01

    Full Text Available A new class of porphyrin(Pp/Fe co-loaded TiO2 composites opportunely prepared by impregnation of [5,10,15,20-tetra(4-tert-butylphenyl] porphyrin (H2Pp or Cu(II[5,10,15,20-tetra(4-tert-butylphenyl] porphyrin (CuPp onto Fe-loaded TiO2 particles showed high activities by carrying out the degradation of 4-nitrophenol (4-NP as probe reaction in aqueous suspension under heterogeneous photo-Fenton-like reactions by using UV-visible light. The combination of porphyrin-Fe-TiO2 in the presence of H2O2 showed to be more efficient than the simple bare TiO2 or Fe-TiO2.

  11. 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...... that the decoloration of X-GN followed a pseudo-first order reaction and the activation energy was 17.2 kJ/mol. Iron leaching from AC-FeOOH occurred during the reaction, but the decoloration efficiency of X-GN was still higher than 80% after four runs. The AC-FeOOH has a good stability and can be reused. Besides...

  12. Photo-Fenton oxidation of 3-amino-5-methylisoxazole: a by-product from biological breakdown of some pharmaceutical compounds.

    Science.gov (United States)

    Souza, Bianca M; Marinho, Belisa A; Moreira, Francisca C; Dezotti, Márcia W C; Boaventura, Rui A R; Vilar, Vítor J P

    2015-11-10

    The present study aims to assess the removal of 3-amino-5-methylisoxazole (AMI), a recalcitrant by-product resulting from the biological breakdown of some pharmaceuticals, applying a solar photo-Fenton process assisted by ferrioxalate complexes (SPFF) (Fe(3+)/H2O2/oxalic acid/UVA-Vis) and classical solar photo-Fenton process (SPF) (Fe(2+)/H2O2/UVA-Vis). The oxidation ability of SPFF was evaluated at different iron/oxalate molar ratios (1:3, 1:6, and 1:9, with [total iron] = 3.58 × 10(-2) mM and [oxalic acid] = 1.07 × 10(-1), 2.14 × 10(-1) and 3.22 × 10(-1) mM, respectively) and pH values (3.5-6.5), using low iron contents (2.0 mg Fe(3+) L(-1)). Additionally, the use of other organic ligands such as citrate and ethylenediamine-N,N'-disuccinic acid (EDDS) was tested. The oxidation power of the classical SPF was assessed at different pH values (2.8-4.0) using 2.0 mg Fe(2+) per liter. Furthermore, the effect of AMI concentration (2-20 mg L(-1)), presence of inorganic ions (Cl(-), SO4(2-), NO3(-), HCO3(-), NH4(+)), and radical scavengers (sodium azide and D-mannitol) on the SPF method at pH 3.5 was also assessed. Experiments were done using a lab-scale photoreactor with a compound parabolic collector (CPC) under simulated solar radiation. A pilot-scale assay was conducted using the best operation conditions. While at near neutral pH, an iron/oxalate molar ratio of 1:9 led to the removal of 72 % of AMI after 90 min of SPFF, at pH 3.5, an iron/oxalate molar ratio of 1:3 was enough to achieve complete AMI degradation (below the detection limit) after 30 min of reaction. The SPF process at pH 3.5 underwent a slower AMI degradation, reaching total AMI degradation after 40 min of reaction. The scale up of SPF process showed a good reproducibility. Oxalic and oxamic acids were identified as the main low-molecular-weight carboxylic acids detected during the pilot-scale SPF reaction. Graphical abstract ᅟ.

  13. Degradation of black liquor from bioethanol process using coagulation and Fenton-like methods

    Science.gov (United States)

    Muryanto, Muryanto; Sari, Ajeng Arum; Abimanyu, Haznan

    2017-01-01

    Black liquor is one of the main by-products of the pretreatment process in bioethanol production from oil palm empty fruit bunches. Black liquor wastewater releases black coloured effluent with high chemical oxygen demand (COD) and low dissolved oxygen (DO). It had a distinctive dark coloration, high alkalinity (pH=13), high organic content (COD > 50,000 ppm) and a high solid content (TSS > 5,000 ppm). Lignin destruction can be done by using high oxidation from OH radical system such as advanced oxidation processes (AOPs). Thereafter, the high concentration of COD, color, and TSS can be removed. The general aim of the present investigation was to determine degradation of black liquor wastewater by using a combined coagulation and Fenton-like methods. In this research, we use Poly Aluminum Chloride (PAC) as a coagulant and FeCl3.6H2O and H2O2 for Fenton-like's reagent. The process was conducted in jar test at 200 rpm for 30 minutes and after that slowly mixed for 2 hours and left for sedimentation 24 hours. 50 ml black liquor was added with variation dose of 1-5% PAC, and 10 % Fenton-like reagent. Hydroxyl radical was generated by the Fenton-like's reagent (ratio FeCl3.6H2O : H2O2 was varied). The highest decolorization of black liquor 70 % was obtained under 5% PAC coagulant. The pH of the wastewater was reduced from 13.00 to 8.07 after the addition of the coagulant. The decolorization of original black liquor was approximately 58% through the Fenton-like process. The combination of PAC and Fenton-like reagent has able to enhance the decolorization of black liquor up to 97%.

  14. Decontamination industrial pharmaceutical wastewater by combining solar photo-Fenton and biological treatment.

    Science.gov (United States)

    Sirtori, C; Zapata, A; Oller, I; Gernjak, W; Agüera, A; Malato, S

    2009-02-01

    Characterization and treatment of a real pharmaceutical wastewater containing 775 mg dissolved organic carbon per liter by a solar photo-Fenton/biotreatment were studied. There were also many inorganic compounds present in the matrix. The most important chemical in this wastewater was nalidixic acid (45 mg/L), an antibiotic pertaining to the quinolone group. A Zahn-Wellens test demonstrated that the real bulk organic content of the wastewater was biodegradable, but only after long biomass adaptation; however, the nalidixic acid concentration remained constant, showing that it cannot be biodegraded. An alternative is chemical oxidation (photo-Fenton process) first to enhance biodegradability, followed by a biological treatment (Immobilized Biomass Reactor--IBR). In this case, two studies of photo-Fenton treatment of the real wastewater were performed, one with an excess of H2O2 (kinetic study) and another with controlled H2O2 dosing (biodegradability and toxicity studies). In the kinetic study, nalidixic acid completely disappeared after 190 min. In the other experiment with controlled H2O2, nalidixic acid degradation was complete at 66 mM of H2O2 consumed. Biodegradability and toxicity bioassays showed that photo-Fenton should be performed until total degradation of nalidixic acid before coupling a biological treatment. Analysis of the average oxidation state (AOS) demonstrated the formation of more oxidized intermediates. With this information, the photo-Fenton treatment time (190 min) and H2O2 dose (66 mM) necessary for adequate biodegradability of the wastewater could be determined. An IBR operated in batch mode was able to reduce the remaining DOC to less than 35 mg/L. Ammonium consumption and NO3- generation demonstrated that nitrification was also attained in the IBR. Overall DOC degradation efficiency of the combined photo-Fenton and biological treatment was over 95%, of which 33% correspond to the solar photochemical process and 62% to the biological

  15. 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.

  16. 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.

  17. Experimental Study on Treatment of Pharmaceutical Wastewater with UV-Fenton Oxidation%UV-Fenton法预处理某制药厂废水的实验研究

    Institute of Scientific and Technical Information of China (English)

    陈琳; 张争民

    2015-01-01

    The pharmaceutical wastewater, a class of industrial wastewater, is characterized by high concentra⁃tion and low bio-degradability. The treatment efficiency had been compared between Fenton and UV-Fenton of dosage, initial pH, reaction time, and so on. The results showed that the treatment efficiency of UV-Fen⁃ton oxidation process was better than Fenton. The optimal reaction conditions of Fenton were as follows: the dosage of FeSO4·7H2O and H2O2 were 0.036 mol/L and 0.128 mol/L respectively, the initial pH was 4.3, the reaction time was 2h, and the removal efficiency of CODCr was 43.9%. However, the optimal conditions of UV-Fenton were as follows: the dosage of FeSO4·7H2O and H2O2 were 0.029 mol/L and 0.102 mol/L respec⁃tively, the initial pH was 4.3, the reaction time of UV and Fenton were 7 min and 75 min respectively and the removal efficiency of CODCr was 63.5%. What’s more, the B/C was increased to 0.39, which showed that UV-Fenton oxidation could improve biodegradability of the pharmaceutical wastewater.%制药废水是一种难生物降解的高浓度有机工业废水,处理困难.研究以某制药股份有限公司综合排放废水为对象,分别采用Fenton和UV-Fenton法对制药废水进行处理,分析试剂投加量、反应初始pH和反应时间等对反应的影响.结果表明,Fenton法处理制药废水的最佳条件为:FeSO4·7H2O投加0.036 mol/L,H2O2投加0.128 mol/L,初始pH为4.3,反应时间为2 h,CODCr去除率为43.9%. UV-Fenton法处理制药废水缩短反应时间,减少试剂投加量,最佳处理条件为:UV处理时间为7 min,FeSO4·7H2O投加0.029 mol/L,H2O2投加0.102 mol/L,初始pH为4.3,反应时间为75 min,最佳条件下CODCr去除率优于Fenton法,可达63.5%,且污水B/C增至0.39,提高可生化性.

  18. Heterogeneous photo-Fenton-like catalysts Cu2V2O7 and Cr2V4O13 for an efficient removal of azo dye in water

    Directory of Open Access Journals (Sweden)

    Sangeeta Kalal

    2016-12-01

    Full Text Available This work deals with the degradation of non-biodegradable azo-dye (Evans blue by the heterogeneous photo-Fenton-like process using copper pyrovanadate (Cu2V2O7 and chromium tetravanadate (Cr2V4O13 as catalysts, which have been prepared by wet chemical method. These catalysts were characterized by different techniques such as scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and Brunauer–Emmett–Teller surface area analysis. The effect of various parameters such as initial pH, concentration of dye, amount of catalyst, amount of H2O2, and light intensity on the reaction rate has also been studied. Photodegradation efficiency was found 77.78 and 79% for copper pyrovanadate (Cu2V2O7 and chromium tetravanadate (Cr2V4O13, respectively. A tentative mechanism involving ·OH radicals as an oxidant for the degradation of dye has also been proposed. The observations revealed that the rate of photo-Fenton-like degradation of dye follows pseudo-first-order kinetics.

  19. Fenton degradation of sulfanilamide in the presence of Al,Fe-pillared clay: Catalytic behavior and identification of the intermediates.

    Science.gov (United States)

    Khankhasaeva, Sesegma Ts; Dambueva, Darima V; Dashinamzhilova, Elvira Ts; Gil, Antonio; Vicente, Miguel A; Timofeeva, Maria N

    2015-08-15

    Liquid phase catalytic degradation of sulfanilamide with H2O2 was carried out in the presence of Fe,Al/M-pillared clay (Fe,Al/M-MM, M=Na(+), Ca(2+) and Ba(2+)) as heterogeneous Fenton type catalyst. Fe,Al/M-MMs were prepared by swelling of layered aluminosilicate (90-95 wt.% montmorillonite) from a bed located in Mukhortala (Buryatia, Russia) in Na(+), Ca(2+) and Ba(2+) forms by means of the exchange of these cations with bulky Fe,Al-polyoxocations prepared at Al/Fe=10/1 and OH/(Al+Fe)=2.0, and then calcinated at 500°C. XRD method and chemical analysis demonstrated that the rate of crystalline swelling was dependent on the interlayer cations and decreased in the order: Fe,Al-/Na-MM>Fe,Al/Ca-MM>Fe,Al/Ba-MM. It was found that the catalytic properties of Fe,Al/M-MMs depended on the type of exchangeable cations. The effect of the H2O2/sulfanilamide molar ratio, the catalyst content, the reaction temperature and the reaction pH on the removal rate of sulfanilamide has been studied in the presence of Fe,Al/Na-MM. The catalyst can be applied for degradation of sulfanilamide with H2O2 for at least three successive cycles without loss of activity. HPLC analyses pointed out that the main degradation intermediate products were sulfanilic acid, benzenesulfonic acid, p-benzoquinone and aliphatic carboxylic acids.

  20. Biosynthesised magnetic iron nanoparticles for sludge dewatering via Fenton process.

    Science.gov (United States)

    Ealias, Anu Mary; Jose, Jephin Varughese; Saravanakumar, M P

    2016-11-01

    The magnetic iron nanoparticles (MFeNp) were biosynthesised using the extract of Cinnamomum tamala (bay leaf) and examined for its efficacy on sludge dewatering. The characteristics of MFeNp were studied using scanning electron microscope (SEM), transmission electron microscopy (TEM), x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and x-ray photoelectron spectrometer (XPS) techniques. The presence of polyphenolic compounds were confirmed by FTIR and XPS analysis. The reduction in capillary suction time (CST) (71.36 to 16.5 s) and specific resistance to filtration (SRF) (53.71 × 10(11) to 1.47 × 10(11) m/kg) values have indicated that the use of Fenton nanocatalyst enhanced the sludge dewaterability. The differential scanning calorimetry (DSC) analysis has shown that the mass of bound water in the treated sludge was decreased significantly from 1.45 to 0.92 kg H2O/kg DS. The breakdown of extracellular polymeric substances (EPS) by the MFeNp leads to the significant reduction in proteins, polysaccharides, water content and heavy metals. The optimisation using response surface modelling (RSM) have shown that the maximum removal efficiency of water from the sludge was 85.9 % when the optimum pH (3) MFeNp dosage (50 mg/g DS) and H2O2 dosage (500 mg/g DS) were maintained. The experimental results and the statistical optimisation have suggested that MFeNp can be used as a potential nanocatalyst for the sludge dewaterability and hence it can be used for the agricultural purpose. Graphical abstract Schematic representation of sludge dewatering process.

  1. Treatment of a sanitary landfill leachate using combined solar photo-Fenton and biological immobilized biomass reactor at a pilot scale.

    Science.gov (United States)

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

    2011-04-01

    A solar photo-Fenton process combined with a biological nitrification and denitrification system is proposed for the decontamination of a landfill leachate in a pilot plant using photocatalytic (4.16 m(2) of Compound Parabolic Collectors - CPCs) and biological systems (immobilized biomass reactor). The optimum iron concentration for the photo-Fenton reaction of the leachate is 60 mg Fe(2+) L(-1). The organic carbon degradation follows a first-order reaction kinetics (k = 0.020 L kJ(UV)(-1), r(0) = 12.5 mg kJ(UV)(-1)) with a H(2)O(2) consumption rate of 3.0 mmol H(2)O(2) kJ(UV)(-1). Complete removal of ammonium, nitrates and nitrites of the photo-pre-treated leachate was achieved by biological denitrification and nitrification, after previous neutralization/sedimentation of iron sludge (40 mL of iron sludge per liter of photo-treated leachate after 3 h of sedimentation). The optimum C/N ratio obtained for the denitrification reaction was 2.8 mg CH(3)OH per mg N-NO(3)(-), consuming 7.9 g/8.2 mL of commercial methanol per liter of leachate. The maximum nitrification rate obtained was 68 mg N-NH(4)(+) per day, consuming 33 mmol (1.3 g) of NaOH per liter during nitrification and 27.5 mmol of H(2)SO(4) per liter during denitrification. The optimal phototreatment energy estimated to reach a biodegradable effluent, considering Zahn-Wellens, respirometry and biological oxidation tests, at pilot plant scale, is 29.2 kJ(UV) L(-1) (3.3 h of photo-Fenton at a constant solar UV power of 30 W m(-2)), consuming 90 mM of H(2)O(2) when used in excess, which means almost 57% mineralization of the leachate, 57% reduction of polyphenols concentration and 86% reduction of aromatic content.

  2. 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

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

    Science.gov (United States)

    Rodrigues, Carmen S D; Madeira, Luis M; Boaventura, Rui A R

    2009-12-30

    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 11.5h; 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, BOD(5) 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.

  4. 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.

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

    Science.gov (United States)

    Lei, Yangming; Liu, Hong; Shen, Zhemin; Wang, Wenhua

    2013-10-15

    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, H2O2 was generated with a current of 0.3A 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 H2O2 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(-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 3h.

  6. Degradation of sulfamethoxazole in water by solar photo-Fenton. Chemical and toxicological evaluation.

    Science.gov (United States)

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

    2009-09-01

    In this work, the photocatalytic degradation of the antibiotic sulfamethoxazole (SMX) by solar photo-Fenton at pilot plant scale was evaluated in distilled water (DW) and in seawater (SW). Degradation and mineralization of SMX were strongly hindered in SW compared to DW. The influence of H(2)O(2) and iron concentration on the efficiency of the photocatalytic process was evaluated. An increase in iron concentration from 2.6 to 10.4 mg L(-1) showed only a slight improvement in SMX degradation and mineralization. However, an increase in H(2)O(2) concentration up to 120 mg L(-1) during photo-Fenton in DW decreased SMX solution toxicity from 85% to 20%, according to results of Daphnia magna bioassays. The same behaviour was not observed after photo-Fenton treatment in SW. Despite 45% mineralization in SW, toxicity increased from 16% to 86% as shown by Vibrio fischeri bioassays, which suggests that the intermediates generated in SW are different from those in DW. A SMX degradation pathway during the photo-Fenton treatment in DW is proposed.

  7. 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.

  8. Continuous combined Fenton's oxidation and biodegradation for the treatment of pentachlorophenol-contaminated water.

    Science.gov (United States)

    Zimbron, Julio A; Reardon, Kenneth F

    2011-11-01

    Pentachlorophenol (PCP) was studied as a model recalcitrant compound for a sequential chemical oxidation and biodegradation treatment, in a continuous laboratory-scale system that combined a Fenton's chemical reactor and a packed-bed bioreactor. PCP degradation and dechlorination were observed in the Fenton's reactor at a residence time of 1.5 h, although no reduction of total organic carbon (TOC) was observed. Both PCP degradation and dechlorination were strongly dependent on the H(2)O(2) dose to the chemical reactor. The PCP degradation intermediates tetrachlorohydroquinone and dichloromaleic acid were identified in this reactor. Further treatment of the Fenton's reactor effluent with a packed-bed bioreactor (operating at a residence time of 5.5 h) resulted in partial biodegradation of PCP degradation intermediates and reduction in TOC, although no further reduction of PCP or dechlorination was achieved in the bioreactor. Increased residence time in the bioreactor had no significant impact on degradation of TOC. Recycle of the effluent from the bioreactor to the chemical reactor increased the TOC degradation, but not the extent of the PCP degradation or dechlorination. A mathematical model of the combined Fenton's oxidation and biodegradation system supported the experimental results. While the model over-predicted the PCP and TOC degradation in the combined system, it adequately predicted the sensitivity of these parameters to different H(2)O(2) doses and recycle rates. The model indicated that high recycle rates would improve TOC degradation.

  9. Combined Fenton oxidation and aerobic biological processes for treating a surfactant wastewater containing abundant sulfate.

    Science.gov (United States)

    Wang, Xiao-Jun; Song, Yang; Mai, Jun-Sheng

    2008-12-30

    The present study is to investigate the treatment of a surfactant wastewater containing abundant sulfate by Fenton oxidation and aerobic biological processes. The operating conditions have been optimized. Working at an initial pH value of 8, a Fe2+ dosage of 600mgL(-1) and a H2O2 dosage of 120mgL(-1), the chemical oxidation demand (COD) and linear alkylbenzene sulfonate (LAS) were decreased from 1500 and 490mgL(-1) to 230 and 23mgL(-1) after 40min of Fenton oxidation, respectively. Advanced oxidation pretreatment using Fenton reagent was very effective at enhancing the biodegradability of this kind of wastewater. The wastewater was further treated by a bio-chemical treatment process based on an immobilized biomass reactor with a hydraulic detention time (HRT) of 20h after Fenton oxidation pretreatment under the optimal operating conditions. It was found that the COD and LAS of the final effluent were less than 100 and 5mgL(-1), corresponding to a removal efficiencies of over 94% and 99%, respectively.

  10. Fabrication of biocompatible hydrogel coatings for implantable medical devices using Fenton-type reaction.

    Science.gov (United States)

    Butruk, Beata; Trzaskowski, Maciej; Ciach, Tomasz

    2012-08-01

    In this paper the authors present a simple method of coating polyurethane (PU) surface with poly(vinyl pirrolidone) (PVP) hydrogel. The hydrogel-coated materials were designed for use in biomedical applications, especially in blood-contacting devices. The coating is formed due to free radical macromolecular grafting-crosslinking. Polymer surface was first immersed in an organic solution containing radical source: cumene hydroperoxide (CHP) with an addition of a branching and anchoring agent: ethylene glycol dimethylacrylate (EGDMA). In the second step, the substrate was immersed in a water solution containing given concentration of PVP and Fe(2+). The novelty of the process consists in the fact that free radicals are formed mostly at the polymer/solution interface, what assures high grafting efficiency together with the formation of covalent bonds between polymer substrate and modifying layer. The process was optimized for reagents concentrations. The coating properties: thickness and the swelling ratio were strongly influenced by CHP, Fe(2+), PVP and EGMDA concentrations. The chemical composition of the surface analyzed with FTIR-ATR spectroscopy confirmed the presence of PVP coating. In vitro biocompatibility tests with L929 fibroblasts confirmed non-cytotoxicity of the coatings. Hydrogel coating significantly improved polyurethane hemocompatibility. Studies with human whole blood revealed that both, the platelet consumption and the level of platelet activation were as low as for negative control.

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

    Energy Technology Data Exchange (ETDEWEB)

    Rosales, E.; Iglesias, O.; Pazos, M. [Department of Chemical Engineering, University of Vigo, Isaac Newton Building, Campus As Lagoas, Marcosende 36310, Vigo (Spain); Sanroman, M.A., E-mail: sanroman@uvigo.es [Department of Chemical Engineering, University of Vigo, Isaac Newton Building, Campus As Lagoas, Marcosende 36310, Vigo (Spain)

    2012-04-30

    Highlights: Black-Right-Pointing-Pointer Catalytic activity of Fe alginate gel beads for the remediation of wastewater was tested. Black-Right-Pointing-Pointer New electro-Fenton process for the remediation of polluted wastewater. Black-Right-Pointing-Pointer 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.

  12. Combined humic acid adsorption and enhanced Fenton processes for the treatment of naphthalene dye intermediate wastewater.

    Science.gov (United States)

    Gu, Lin; Zhu, Nanwen; Wang, Liang; Bing, Xiaoxiao; Chen, Xiaoliang

    2011-12-30

    In this work, an humic acid adsorption with an enhanced Fenton oxidation was employed to treat the real effluent originating from the 1-diazo-2-naphthol-4-sulfonic acid (1,2,4-Acid) production plant. In a first step, humic acid with MgSO(4) was selected as adsorbent and precipitant for physicochemical pretreatment, the synergetic effect had led to 39% of COD removal and 89% of colour removal. A multi-staged Fenton oxidation process with inner circulation was introduced subsequently. The TOC, COD, 1,2,4-Acid, NH(4)(+)-N, SS and colour were reduced from 3024 mg/L, 12,780 mg/L, 9103 mg/L, 110 mg/L, 240 mg/L and 25,600 (multiple) to 46 mg/L, 210 mg/L, 21 mg/L, 16 mg/L, 3 mg/L and 25 through the combined process, respectively. Hydrogen peroxide consumed per kg COD had saved up to 36% when two-staged Fenton process with inner circulation (flow-back to influent ratio: 3) was applied. Influence of H(2)O(2) concentration, flow-back to influent ratio and staged Fenton mode were investigated in detail in order to find out the optimal operating parameters. The kinetics of 1,2,4-Acid degradation by two-staged Fenton process was investigated. The evolution of the main intermediates during the degradation process was conducted using the LC-(ESI)-TOF-MS technique, and the results showed a staged degradation pathway from the ring opening of naphthalene compounds to the formation of benzene compounds and carboxyl acids. The combined process had been proved effective in both technical and economic aspects.

  13. 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.

  14. Mechanism of red mud combined with Fenton's reagent in sewage sludge conditioning.

    Science.gov (United States)

    Zhang, Hao; Yang, Jiakuan; Yu, Wenbo; Luo, Sen; Peng, Li; Shen, Xingxing; Shi, Yafei; Zhang, Shinan; Song, Jian; Ye, Nan; Li, Ye; Yang, Changzhu; Liang, Sha

    2014-08-01

    Red mud was evaluated as an alternative skeleton builder combined with Fenton's reagent in sewage sludge conditioning. The results show that red mud combined with Fenton's reagent showed good conditioning capability with the pH of the filtrate close to neutrality, indicating that red mud acted as a neutralizer as well as a skeleton builder when jointly used with Fenton's reagent. Through response surface methodology (RSM), the optimal dosages of Fe(2+), H2O2 and red mud were proposed as 31.9, 33.7 and 275.1 mg/g DS (dry solids), respectively. The mechanism of the composite conditioner could be illuminated as follows: (1) extracellular polymeric substances (EPS), including loosely bound EPS and tightly bound EPS, were degraded into dissolved organics, e.g., proteins and polysaccharides; (2) bound water was released and converted into free water due to the degradation of EPS; and (3) morphology of the conditioned sludge exhibited a porous structure in contrast with the compact structure of raw sludge, and the addition of red mud formed new mineral phases and a rigid lattice structure in sludge, allowing the outflow of free water. Thus, sludge dewatering performance was effectively improved. The economic assessment for a wastewater treatment plant of 370,000 equivalent inhabitants confirms that using red mud conditioning, combined with Fenton's reagent, leads to a saving of approximately 411,000 USD/y or 50.8 USD/t DS comparing with using lime and ordinary Portland cement combined with Fenton's reagent, and approximately 612,000 USD/y or 75.5 USD/t DS comparing with the traditional treatment.

  15. Comparison of Fenton's reagent and adsorption for treatment of industrial container and drum cleaning industry wastewater.

    Science.gov (United States)

    Güneş, Elçin; Çifçi, Deniz İzlen; Çelik, Suna Özden

    2017-03-27

    The present study is aimed to explore the characterization of Industrial Container and Drum Cleaning (ICDC) industry wastewater and treatment alternatives of this wastewater using Fenton and adsorption processes. Wastewater derived from ICDC industry is usually treated by chemical coagulation and biological treatment in Turkey and then discharged in a centralized wastewater treatment facility. It is required that the wastewater COD is below 1500 mg/L to treat in a centralized wastewater treatment facility The wastewater samples characterized for parameters of pH, conductivity, COD, BOD5, TSS, NH3-N, TN, TOC, TP, Cd, Cr, Cu, Fe, Ni, Pb, Zn, Hg. Optimum conditions of adsorption and Fenton processes have been assessed in terms of COD removal. Initial COD values were quite high in the three of samples and were in the range of 11300-14200 mg/L. The optimum conditions were as follows for Fenton treatment; 35-40 g/L for H2O2, 2-5 g/L for Fe(2+) and 13-36 for H2O2/Fe(2+) molar ratio. The optimum conditions of PAC doses and contact times in adsorption studies were 20-30 g/L and 5-12 hours respectively. In terms of COD removal, the efficiency of the Fenton process was found to be about 91-97%, and the efficiency of the adsorption process was found to be 88-98%. COD, BOD5, TOC, TP, Cd, Cr, Cu, Fe, Ni, Pb, Zn and Hg removal efficiencies were compared for both Fenton and adsorption processes under optimum conditions for the three samples. The results suggest that these wastewaters are suitable for discharge to a centralized wastewater treatment plant.

  16. Session 6: Novel Heterogeneous Fenton System Based on Fe{sub 3}O{sub 4}/Fe{sup o} Mixtures for the Oxidation of Organics in Aqueous Medium with H{sub 2}O{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Moura, F.C.C.; Araujo, M.H.; Oliveira, G.C.; Fabris, J.D.; Lago, R.M. [Universidade Federal de Minas Gerais, Dept. de Quimica, ICEx (Brazil); Macedo, W.A.; Ardisson, J.D. [Centro de Desenvolvimento de Tecnologia Nuclear, CDTN, MG (Brazil)

    2004-07-01

    In this work it is described a novel heterogeneous Fenton system based on Fe{sub 3}O{sub 4}/Fe{sup o} mixtures which showed high activity for the decomposition of H{sub 2}O{sub 2} and the oxidation of organics with H{sub 2}O{sub 2}. Moessbauer spectroscopy, X-ray diffraction, temperature programmed reduction and magnetization measurements suggest that a surface reaction takes place between Fe{sub 3}O{sub 4} and Fe{sup o} during manual grinding forming a highly active system. (authors)

  17. Microorganisms inactivation in wastewater by solar photo-Fenton at neutral pH; Inactivacion de microorganismos presentes en aguas mediante foto-Feton solar a pH neutro

    Energy Technology Data Exchange (ETDEWEB)

    Ortega Gomez, E.

    2015-07-01

    The global fresh water shortage, caused mainly by the drought and the pollution of sources, is one of the main environmental problems currently affecting the human race. Over the last few decades, water quality requirements for use in different activities has obliged us to find alternative solutions which requires a concerted effort at a scientific as well as political, economic and social level. In particular, treated wastewater recycling has come up recently as a source provision for sectors where high water quantities are consumed. In this regard, the main sector to benefit is agriculture, which produces the 60% of global food, according to Food and Agriculture Organization (FAO). As such, treatments that are able to guarantee water microbiological quality, as stated by governing law, are necessary and resolve disadvantages or problems with current treatment, Amongst new technologies available for wastewater regeneration, a noteworthy point is the high level of efficiency in Advanced Oxidation Processes (AOPs). Furthermore, those that are capable of using sunlight as a radiation source are of special interest, particularly the homogeneous photocatalytic process, solar photo-Fenton. Generally speaking, in Fenton reactions, an oxidant agent (H2O2) reacts with a catalyst (Fe2+) generating hydroxyl radicals, which are high oxidant and non-selective species causing the inactivation of several microorganisms. The presence of UV-A photons in sunlight leads to catalyst regeneration and the production of more hydroxyl radicals. One of the main goals of this research work has been to improve the knowledge about the microorganism inactivation process through solar photo-Fenton at neutral pH, which has been scarcely studied, for application as a tertiary treatment in a wastewater treatment plant (WWTP). With this aim in mind, the bacteria Enterococus faecalis (Gram-positive microorganism) has been used as a fecal pollution indicator since it has not been studied in great

  18. 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.

  19. 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)

  20. 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.

  1. Optimization of the azo dye Procion Red H-EXL degradation by Fenton's reagent using experimental design.

    Science.gov (United States)

    Rodrigues, Carmen S D; Madeira, Luis M; Boaventura, Rui A R

    2009-05-30

    Chemical oxidation by Fenton's reagent of a reactive azo dye (Procion Deep Red H-EXL gran) solution has been optimized making use of the experimental design methodology. The variables considered for the oxidative process optimization were the temperature and the initial concentrations of hydrogen peroxide and ferrous ion, for a dye concentration of 100mg/L at pH 3.5, the latter being fixed after some preliminary runs. Experiments were carried out according to a central composite design approach. The methodology employed allowed to evaluate and identify the effects and interactions of the considered variables with statistical meaning in the process response, i.e., in the total organic carbon (TOC) reduction after 120 min of reaction. A quadratic model with good adherence to the experimental data in the domain analysed was developed, which was used to plot the response surface curves and to perform process optimization. It was concluded that temperature and ferrous ion concentration are the only variables that affect TOC removal, and due to the cross-interactions, the effect of each variable depends on the value of the other one, thus affecting positively or negatively the process response.

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

    Science.gov (United States)

    Garcia-Segura, Sergi; Almeida, Lucio Cesar; Bocchi, Nerilso; Brillas, Enric

    2011-10-30

    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(-1) MCPA solutions in 0.05 M Na(2)SO(4) at a liquid flow rate of 180 L h(-1) with an average UV irradiation intensity of about 32 Wm(-2). The optimum variables found for the SPEF process were 5.0 A, 1.0mM Fe(2+) and pH 3.0 after 120 min of electrolysis. Under these conditions, 75% of mineralization with 71% of current efficiency and 87.7 k Wh kg(-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.

  3. Bioelectro-Fenton: A sustainable integrated process for removal of organic pollutants from water: Application to mineralization of metoprolol.

    Science.gov (United States)

    Olvera-Vargas, Hugo; Cocerva, Tatiana; Oturan, Nihal; Buisson, Didier; Oturan, Mehmet A

    2016-12-05

    The relevant environmental hazard related to the presence of pharmaceuticals in water sources requires the development of high effective and suitable wastewater treatment technologies. In the present work, a hybrid process coupling electro-Fenton (EF) process and aerobic biological treatment (Bio-EF process) was implemented for the efficient and cost-effective mineralization of beta-blocker metoprolol (MPTL) aqueous solutions. Firstly, operating factors influencing EF process were assessed. MTPL solutions were completely mineralized after 4h-electrolysis under optimal operating conditions and BDD anode demonstrated its oxidation superiority. The absolute rate constant of MTPL oxidation byOH (kMTPL) was determined by the competition kinetics method and found to be (1.72±0.04)×10(9)M(-1)s(-1). A reaction pathway for the mineralization of the drug was proposed based on the identification of oxidation by-products. Secondly, EF process was used as pre-treatment. An increase of BOD5/COD ratio from 0.012 to 0.44 was obtained after 1h EF treatment, along with 47% TOC removal and a significant decrease of toxicity, demonstrating the feasibility of a post-biological treatment. Finally, biological treatment successfully oxidized 43% of the total TOC content. An overall 90% mineralization of MPTL solutions was achieved by the Bio-EF process, demonstrating its potentiality for treating wastewater containing pharmaceutical residues.

  4. Oxidation of atrazine in aqueous media by solar- enhanced Fenton-like process involving persulfate and ferrous ion.

    Science.gov (United States)

    Khandarkhaeva, Marina; Batoeva, Agniya; Aseev, Denis; Sizykh, Marina; Tsydenova, Oyuna

    2017-03-01

    The oxidation of s-triazines (using atrazine (ATZ) as a model compound) by a solar-enhanced Fenton-like process involving persulfate and ferrous ion was studied. A flow-through tubular photoreactor was employed for the experiments. The solar-enhanced oxidative system involving ferrous ion and persulfate (Solar/S2O8(2-)/Fe(2+)) showed the highest ATZ degradation efficiency when compared with other treatments (unactivated S2O8(2-), Solar - sunlight only, S2O8(2-)/Fe(2+), Solar/S2O8(2-)). Complete degradation of ATZ and 20% reduction in total organic carbon (TOC) content were observed after 30min of the treatment. The in situ generated (•)ОН and SO4(-•) radicals were shown to be involved in ATZ oxidation using the radical scavengers methanol and tert-butyl alcohol. Furthermore, iron compounds were shown to act not only as catalysts but also as photo-sensitizers, as the introduction of ferrous ion into the reaction mixture led to an increased absorbance of the solution and expansion of the absorption spectrum into the longer wavelength spectral region.

  5. Heterogeneous Fenton-Like Catalytic Removal of Methylene Blue Dye in Water Using Magnetic Nanocomposite (MCM-41/Magnetite

    Directory of Open Access Journals (Sweden)

    André E. Nogueira

    2014-01-01

    Full Text Available In this work, MCM-41, magnetite (MAG, and a composite of magnetite and MCM-41 (MCM-MAG were synthesized by a simple route for the production of active systems in the decomposition of organic waste. The materials were characterized by N2 adsorption/desorption, X-ray diffraction analysis (XRD, temperature programmed reduction (TPR, Fourier transform infrared spectroscopy (FTIR, and transmission electron microscopy (TEM. Our results indicated that the decolorization kinetics of the dyes were in the order of MCM-MAG > MCM-41 > magnetite. Mineralization of the dyes was monitored by total organic carbon (TOC decrease. The dye solutions could be completely decolorized and effectively mineralized, with an average overall TOC removal 43% for a Fenton-like reaction time of 180 min. The degradation activity of the MCM-MAG was stable during four consecutive experiments, confirming their stability and reusability of the composite. The great advantage of this composite is that it may be easily magnetically recovered and reused.

  6. Mineralization of synthetic and industrial pharmaceutical effluent containing trimethoprim by combining electro-Fenton and activated sludge treatment

    OpenAIRE

    Mansour, Dorsaf; Fourcade, Florence; Soutrel, Isabelle; Hauchard, Didier; Bellakhal, Nizar; Amrane, Abdeltif

    2015-01-01

    International audience; A combined process coupling of an electro-Fenton and a biological degradation was investigated in order to mineralize synthetic and industrial pharmaceutical effluent containing trimethoprim, a bacteriostatic antibiotic. Electro-Fenton degradation of trimethoprim was optimized by means of a Doehlert experimental design, showing that 0.69 mM Fe2+, 466 mA and 30 min electrolysis time were optimal, leading to total trimethoprim removal, while mineralization remained limit...

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

    Energy Technology Data Exchange (ETDEWEB)

    Monteagudo, J.M., E-mail: josemaria.monteagudo@uclm.es [University of Castilla-La Mancha, Grupo IMAES, Department of Chemical Engineering, Escuela Tecnica Superior de Ingenieros Industriales, Avda. Camilo Jose Cela, 1, 13071 Ciudad Real (Spain); Duran, A.; Aguirre, M.; San Martin, I. [University of Castilla-La Mancha, Grupo IMAES, Department of Chemical Engineering, Escuela Tecnica Superior de Ingenieros Industriales, Avda. Camilo Jose Cela, 1, 13071 Ciudad Real (Spain)

    2011-01-15

    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 H{sub 2}O{sub 2}, 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 H{sub 2}O{sub 2} 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, k{sub TOC}, increased as initial Fe(II) and H{sub 2}O{sub 2} concentrations and temperature increased. The optimum pH value also slightly increased with greater Fe(II) and hydrogen peroxide concentrations but decreased when temperature increased. {center_dot}OH and O{sub 2}{center_dot}{sup -} radicals were the main oxidative intermediate species in the process, although singlet oxygen ({sup 1}O{sub 2}) also played a role in the mineralization reaction.

  8. Heterogeneous UV/Fenton degradation of bisphenol A catalyzed by synergistic effects of FeCo2O4/TiO2/GO.

    Science.gov (United States)

    Bai, Xue; Lyu, Lingling; Ma, Wenqiang; Ye, Zhengfang

    2016-11-01

    A new method for bisphenol A (BPA) degradation in aqueous solution was developed. The characteristics of BPA degradation in a heterogeneous ultraviolet (UV)/Fenton reaction catalyzed by FeCo2O4/TiO2/graphite oxide (GO) were studied. The properties of the synthesized catalysts were characterized using scanning electron microscopy, X-ray diffraction, and vibrating sample magnetometry. FeCo2O4 and TiO2 were grown as spherical shape, rough surface, and relatively uniform on the surface of GO (FeCo2O4/TiO2/GO). Batch tests were conducted to evaluate the effects of the initial pH, FeCo2O4/TiO2/GO dosage, and H2O2 concentration on BPA degradation. In a system with 0.5 g L(-1) of FeCo2O4/TiO2/GO and 10 mmol L(-1) of H2O2, approximately 90 % of BPA (20 mg L(-1)) was degraded within 240 min of UV irradiation at pH 6.0. The reused FeCo2O4/TiO2/GO catalyst retained its activity after three cycles, which indicates that it is stable and reusable. The heterogeneous UV/Fenton reaction catalyzed by FeCo2O4/TiO2/GO is a promising advanced oxidation technology for treating wastewater that contains BPA.

  9. Fenton氧化技术处理含甲醛废水的实验研究%Experimental Study on Treatment of Formaldehyde Wastewater by Fenton Oxidation Technology

    Institute of Scientific and Technical Information of China (English)

    李勇; 朱素芳; 郑定成

    2012-01-01

    Fenton reagent is used for treating H202 and Fe2 ~ , pH value, reaction time and the dosages of H202 is around 4.5 ml/L,n( min and ended the reaction after stewing 5 wastewater are respectively 89% ,82%. The aldehyde wastewater. formaldehyde wastewater, the effects of the concentration of other factors on the treatment effect are investigated. When n2 02 ) : n ( Fe2 + ) = 4, pH value is 3, the stirring time is 30 rain, formaldehyde removal rate and COD removal rate in result showe that fenton reagent had good effect for the form-aldehyde wastewater.%采用Fenton试剂对甲醛废水进行氧化处理,考察了H2O2浓度、Fe2+浓度、pH值、反应时间等因素对处理效果的影响。在H202投加量为4.5ml/L,n(H202):n(Fe2+)=4,pH值为3,反应30rain后,静置5min的条件下,废水中甲醛去除率和COD去除率分别达到89%、82%。结果表明,Fenton试剂对甲醛废水可以取到很好的处理效果。

  10. 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.

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

    Science.gov (United States)

    Bokare, Alok D; Choi, Wonyong

    2014-06-30

    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 Fe(2+) or Fe(3+) form), metal oxides (e.g., Fe2O3, Fe3O4), and zero-valent metal (Fe(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 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.

  12. 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.

  13. 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.

  14. Oxidation and mineralisation of substituted phenols by Fenton's reagent and catalytic wet oxidation.

    Science.gov (United States)

    Santos, A; Rodriguez, S; Garcia-Ochoa, F; Yustos, P

    2007-01-01

    Catalytic abatement of solutions of 1,000 mg/L in phenol, ortho and para nitrophenol and ortho and para cresols was acomplished by using two catalytic systems. Fenton's reagent was used at 50 degrees C by adding 10 mg/L of ferrous cation and different dosages of H2O2. The mixture was reacting isothermically in a batch way during 3 hours. Catalytic wet oxidation (CWO) was carried out by using a commercial Activated Carbon, Industrial React FE01606A, CWO runs were carried out in a fixed bed reactor (FBR) with concurrent upflow. Temperature and oxygen pressure of the reactor were set to 160 degrees C and 16 bar, respectively. While phenols are quicky oxidised by the Fenton reagent higher mineralisation was obtained in the CWO process.

  15. 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.

  16. Tratamento de efluente tÃxtil utilizando o processo foto-fenton

    OpenAIRE

    Diego Ricieri Manenti

    2011-01-01

    O objetivo deste trabalho à avaliar o desempenho do processo foto-Fenton, utilizando energia solar e artificial como fontes de irradiaÃÃo UV, no tratamento de efluentes tÃxteis. Foram realizados experimentos preliminares para avaliar a eficiÃncia do processo foto-Fenton na mineralizaÃÃo e degradaÃÃo dos poluentes orgÃnicos e inorgÃnicos, bem como dos corantes sintÃticos. Para tanto, foi preparado o efluente tÃxtil sintÃtico pela mistura de seis corantes: Laranja TGL (C25H33ClN6O6S2), Azul FGL...

  17. 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.

  18. Effect of pH and H2O2 dosage on catechol oxidation in nano-Fe3O4 catalyzing UV-Fenton and identification of reactive oxygen species

    DEFF Research Database (Denmark)

    Li, Weiguang; Wang, Yong; Angelidaki, Irini

    2014-01-01

    .0-8.0), this heterogeneous UV-Fenton process was powerful, especially reaction at pH 7.0 obtaining the highest COD removal of 93%. The remarkably high oxidation efficiency under neutral and slightly basic conditions was due to fast decrease of solution pH to be strongly acidic. Solution pH decreased until 120min...... dosage of 11.80mM for complete oxidation of 100mgL-1 catechol) to 1.00×δH2O2. Radical identification experiments based on inhibition of methylene blue degradation rate under respective scavenger for HO, O21 and HO2 showed HO, O21 and O2- were involved in nano-Fe3O4 catalyzing UV-Fenton, and total...

  19. Optimizing photo-Fenton like process for the removal of diesel fuel from the aqueous phase

    OpenAIRE

    Dehghani, Mansooreh; Shahsavani, Esmaeel; Farzadkia, Mahdi; Samaei, Mohammad Reza

    2014-01-01

    Background In recent years, pollution of soil and groundwater caused by fuel leakage from old underground storage tanks, oil extraction process, refineries, fuel distribution terminals, improper disposal and also spills during transferring has been reported. Diesel fuel has created many problems for water resources. The main objectives of this research were focused on assessing the feasibility of using photo-Fenton like method using nano zero-valent iron (nZVI/UV/H2O2) in removing total petro...

  20. 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.

  1. Dégradation des polluants organiques par la technologie électro-fenton

    OpenAIRE

    Özcan, Ali

    2010-01-01

    In this thesis, a detailed investigation has been carried out on the use of electro-Fenton technique for the oxidation of the some persistent organic pollutants for the sake of water remediation. This technique produces •OH radicals electrocatalytically and uses them to oxidize the organic pollutants. The overall study can be divided into three parts. In the first part, the removal of selected synthetic dyes and pesticides from water was investigated by using carbon felt (CF) cathode. The oxi...

  2. Use of Fenton oxidation to improve the biodegradability of a pharmaceutical wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Tekin, Huseyin [ENCON Environmental Consultancy Co., Mahatma Gandhi Caddesi 75/3, Gaziosmanpasa, 06700 Ankara (Turkey); Bilkay, Okan [ENCON Environmental Consultancy Co., Mahatma Gandhi Caddesi 75/3, Gaziosmanpasa, 06700 Ankara (Turkey); Ataberk, Selale S. [ENCON Environmental Consultancy Co., Mahatma Gandhi Caddesi 75/3, Gaziosmanpasa, 06700 Ankara (Turkey); Balta, Tolga H. [ENCON Environmental Consultancy Co., Mahatma Gandhi Caddesi 75/3, Gaziosmanpasa, 06700 Ankara (Turkey); Ceribasi, I. Haluk [ENCON Environmental Consultancy Co., Mahatma Gandhi Caddesi 75/3, Gaziosmanpasa, 06700 Ankara (Turkey); Sanin, F. Dilek [Department of Environmental Engineering, Middle East Technical University, 06531 Ankara (Turkey); Dilek, Filiz B. [Department of Environmental Engineering, Middle East Technical University, 06531 Ankara (Turkey); Yetis, Ulku [Department of Environmental Engineering, Middle East Technical University, 06531 Ankara (Turkey)]. E-mail: uyetis@metu.edu.tr

    2006-08-21

    The applicability of Fenton's oxidation to improve the biodegradability of a pharmaceutical wastewater to be treated biologically was investigated. The wastewater was originated from a factory producing a variety of pharmaceutical chemicals. Treatability studies were conducted under laboratory conditions with all chemicals (having COD varying from 900 to 7000 mg/L) produced in the factory in order to determine the operational conditions to utilize in the full-scale treatment plant. Optimum pH was determined as 3.5 and 7.0 for the first (oxidation) and second stage (coagulation) of the Fenton process, respectively. For all chemicals, COD removal efficiency was highest when the molar ratio of H{sub 2}O{sub 2}/Fe{sup 2+} was 150-250. At H{sub 2}O{sub 2}/Fe{sup 2+} ratio of 155, 0.3 M H{sub 2}O{sub 2} and 0.002 M Fe{sup 2+}, provided 45-65% COD removal. The wastewater treatment plant that employs Fenton oxidation followed by aerobic degradation in sequencing batch reactors (SBR), built after these treatability studies provided an overall COD removal efficiency of 98%, and compliance with the discharge limits. The efficiency of the Fenton's oxidation was around 45-50% and the efficiency in the SBR system which has two reactors each having a volume of 8 m{sup 3} and operated with a total cycle time of 1 day, was around 98%, regarding the COD removal.

  3. Determination of organic compounds in landfill leachates treated by Fenton-Adsorption.

    Science.gov (United States)

    Ramírez-Sosa, Dorian R; Castillo-Borges, Elba R; Méndez-Novelo, Roger I; Sauri-Riancho, María R; Barceló-Quintal, Manuel; Marrufo-Gómez, José M

    2013-02-01

    The objective of this study was to identify the organic compounds removed from the leachate when treated with Fenton-Adsorption by gas chromatography coupled to mass spectrometry (GC-MS) in order to identify toxic compounds that could be harmful for the environment or human health. The physicochemical characterization of the raw leachate was carried out before and after the Fenton-Adsorption process. The effluent from each stage of this process was characterized: pH, Biological Oxygen Demand (BOD(5)), Chemical Oxygen Demand (COD), Total Organic Carbon (TOC), Total Carbon (TC), Inorganic Carbon (IC), Total Solids (TS), Total Suspended Solids (TSS) and Color. The organic compounds were determined by GC-MS. The removal of COD and color reached over 99% in compliance with the Mexican Standard NOM-001-SEMARNAT-1996, which establishes the maximum permissible limits for contaminants present in wastewater discharges to water and national goods. The chromatographic analysis from the Fenton-Adsorption effluent proved that this treatment removed more than 98% of the organic compounds present in the initial sample. The mono (2-ethylhexyl) ester 1,2-benzenedicarboxylic acid persisted, although it is not considered as toxic compound by the NOM-052-SEMARNAT-2005. Therefore, the treated effluent can be safely disposed of into the environment.

  4. 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.

  5. 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.

  6. A study of the Fenton-mediated oxidation of methylene blue-cucurbit[n]uril complexes.

    Science.gov (United States)

    Fuenzalida, Tomás; Fuentealba, Denis

    2015-04-01

    Cucurbit[n]urils efficiently decreased the Fenton-mediated oxidation of encapsulated dyes, providing a mechanism for some control and selectivity over the degradation. The encapsulation of methylene blue into cucurbit[7]uril made it highly refractory against Fenton oxidation in the dark or under UVA light irradiation. However, the oxidation of the encapsulated dye was significantly enhanced under visible light irradiation. This behavior was selective for the cucurbit[7]uril complex and not for the cucurbit[8]uril complex, which achieved the same degree of protection irrespective of the irradiation conditions. This different reactivity of the complexes was further discussed in terms of their excited state properties. The main mechanism for protection was the seclusion of the dye into cucurbit[n]urils as shown by the fact that the non-encapsulated dye safranin was protected much less than methylene blue. Additionally, cucurbit[n]urils efficiently trapped hydroxyl radicals, which contributed significantly to the protection of the dyes from Fenton-mediated oxidation.

  7. Combined treatment of olive mill wastewater by Fenton's reagent and anaerobic biological process.

    Science.gov (United States)

    Amor, Carlos; Lucas, Marco S; García, Juan; Dominguez, Joaquín R; De Heredia, J Beltrán; Peres, José A

    2015-01-01

    This work presents the application of Fenton's reagent process combined with anaerobic digestion to treat an olive mill wastewater (OMW). Firstly, OMW was pre-treated by chemical oxidation in a batch reactor with Fenton's reagent, using a fixed H2O2/COD ratio of 0.20, pH = 3.5 and a H2O2/Fe(2+) molar ratio of 15:1. This advanced oxidation treatment allowed reaching reductions of 17.6 and 82.5% of chemical oxygen demand (COD) and total polyphenols (TP), respectively. Secondly, OMW treatment by anaerobic digestion was performed using previously adapted microorganisms immobilized in Sepiolite. These biological tests were carried out varying the substrate concentration supplied to the reactor and COD conversions from 52 to 74% were obtained. Afterwards, Fenton's reagent followed by anaerobic digestion was applied to OMW treatment. This combined process presented a significant improvement on organic load removal, reaching COD degradations from 64 to 88%. Beyond the pollutant load removal, it was also monitored the yield of methane generated throughout anaerobic experiments. The methane produced ranged from 281 cm(3) to 322 cm(3) of CH4/g COD removed. Additionally, a methane generation kinetic study was performed using the Monod Model. The application of this model allowed observing a kinetic constant increase of the combined process (kFN = 0.036 h(-1)) when compared to the single anaerobic process (kF = 0.017 h(-1)).

  8. 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.

  9. 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.

  10. 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).

  11. 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.

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

    Science.gov (United States)

    El-Ghenymy, Abdellatif; Garcia-Segura, Sergi; Rodríguez, Rosa María; Brillas, Enric; El Begrani, Mohamed Soussi; Abdelouahid, Ben Ali

    2012-06-30

    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 2.5L of sulfanilic acid solutions in 0.05M Na(2)SO(4). Electrolyses were performed with a pre-pilot flow plant containing a Pt/air diffusion reactor generating H(2)O(2). In SPEF, it was coupled with a solar photoreactor under an UV irradiation intensity of ca. 31Wm(-2). Optimum variables of 100mAcm(-2), 0.5mM Fe(2+) and pH 4.0 were determined after 240min of EF and 120min of SPEF. Under these conditions, EF gave 47% of mineralization, whereas SPEF was much more powerful yielding 76% mineralization with 275kWh kg(-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(2)O(2) and added Fe(2+). The quick photolysis of these complexes by UV light of sunlight explains the higher oxidation power of SPEF. NH(4)(+) was the main inorganic nitrogen ion released in both processes.

  13. Ultrasonic Fenton-like catalytic degradation of bisphenol A by ferroferric oxide (Fe₃O₄) nanoparticles prepared from steel pickling waste liquor.

    Science.gov (United States)

    Huang, Ruixiong; Fang, Zhanqiang; Fang, Xiaobo; Tsang, Eric Pokeung

    2014-12-15

    In this study, Fe3O4 NPs (named as Fe3O4 NPs-PO) were prepared by steel pickling waste liquor to reduce the cost of preparation, and were compared with those obtained by the common co-precipitation method (named as Fe3O4 NPs-CP) which prepared from chemical reagent using BET, XRD, XPS, TEM and SEM techniques. The results indicated that Fe3O4 NPs-PO nanoparticles mainly existed in the form of Fe3O4 and appeared to be roughly spherical in shape with a size range of 20-50 nm. The heterogeneous Fenton-like catalytic capacity of Fe3O4 NPs-PO in US+Fe3O4+H2O2 system was comprehensively investigated. BPA could be degraded within a wide pH range of 7-10. The removal efficiencies of BPA were close to 100% and about 45% total organic carbon (TOC) in solution was eliminated at the optimized conditions. It was found that ·OH radicals which mainly caused the degradation of BPA were promptly generated due to the catalysis of the Fe3O4 NPs-PO. Furthermore, the comparative study of catalytic activity, stability and reusability between Fe3O4 NPs-PO and Fe3O4 NPs-CP showed that the two catalysts both remained good activity after several reaction cycles and no significant change in composition and structure was observed, the loss of catalyst was negligible, which demonstrated that Fe3O4 NPs-PO were promising in ultrasonic Fenton-like process to treat refractory organics.

  14. 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.

  15. Photo-Fenton decomposition of β-blockers atenolol and metoprolol; study and optimization of system parameters and identification of intermediates.

    Science.gov (United States)

    Veloutsou, S; Bizani, E; Fytianos, K

    2014-07-01

    Active pharmaceutical compounds reach the wastewater treatment plants mainly through excretion and improper disposal, and, because of insufficient treating methods, they end up to surface water or even potable water in some cases. Atenolol and metoprolol are β-blockers, members of cardiovascular pharmaceuticals group. They are generally used in the treatment of disorders such as hypertension, angina and arrhythmias. They have been in long-term use in Europe and North America, and they have also been detected in the aquatic environment. In this study the degradation of atenolol and metoprolol in aqueous solutions by means of the photo-Fenton reaction was investigated. The purpose of this study was: (i) to investigate the influence of the concentrations of iron and hydrogen peroxide, by means of central composite design, (ii) to study the degradation kinetics in aqueous solutions, (iii) to evaluate the mineralization and the toxicity evolution of the target compounds and (iv) to identify the degradation products. It has been found that increase of iron and hydrogen peroxide concentration accelerate the degradation of atenolol and metoprolol, while the kinetics of the process can be characterized as pseudo-first order. In general the photo-Fenton method has proved to be effective in decomposing and mineralizing the target compounds. The determination of the by-products formed during the degradation using LC-MS/MS equipment and the evaluation of the toxicity of the treated solution in different stages of the process would offer significant, innovative information regarding the treatment of water and wastewater containing active pharmaceutical compounds, especially of the β-blocker group.

  16. Fenton-Like Catalysis and Oxidation/Adsorption Performances of Acetaminophen and Arsenic Pollutants in Water on a Multimetal Cu-Zn-Fe-LDH.

    Science.gov (United States)

    Lu, Hongtao; Zhu, Zhiliang; Zhang, Hua; Zhu, Jianyao; Qiu, Yanling; Zhu, Linyan; Küppers, Stephan

    2016-09-28

    Acetaminophen can increase the risk of arsenic-mediated hepatic oxidative damage; therefore, the decontamination of water polluted with coexisting acetaminophen and arsenic gives rise to new challenges for the purification of drinking water. In this work, a three-metal layered double hydroxide, namely, Cu-Zn-Fe-LDH, was synthesized and applied as a heterogeneous Fenton-like oxidation catalyst and adsorbent to simultaneously remove acetaminophen (Paracetamol, PR) and arsenic. The results showed that the degradation of acetaminophen was accelerated with decreasing pH or increasing H2O2 concentrations. Under the conditions of a catalyst dosage of 0.5 g·L(-1) and a H2O2 concentration of 30 mmol·L(-1), the acetaminophen in a water sample was completely degraded within 24 h by a Fenton-like reaction. The synthesized Cu-Zn-Fe-LDH also exhibited a high efficiency for arsenate removal from aqueous solutions, with a calculated maximum adsorption capacity of 126.13 mg·g(-1). In the presence of hydrogen peroxide, the more toxic arsenite can be gradually oxidized into arsenate and adsorbed at the same time by Cu-Zn-Fe-LDH. For simulated water samples with coexisting arsenic and acetaminophen pollutants, after treatment with Cu-Zn-Fe-LDH and H2O2, the residual arsenic concentration in water was less than 10 μg·L(-1), and acetaminophen was not detected in the solution. These results indicate that the obtained Cu-Zn-Fe-LDH is an efficient material for the decontamination of combined acetaminophen and arsenic pollution.

  17. Study on the sewage residue from dyeing indigo-jeans by ferric-carbon micro-electrolysis and Fenton reagent%Fenton强化微电解工艺处理靛蓝牛仔布印染废水研究

    Institute of Scientific and Technical Information of China (English)

    杨林; 王玉军

    2012-01-01

    研究了铁炭微电解- Fenton试剂作用下靛蓝牛仔布印染废水的脱色和COD去除行为,通过正交试验和单因素试验确定了微电解-Fenton反应的最佳操作条件,分析了各影响因子的作用机理.结果表明:在铁炭质量比为2∶1,pH值为3的条件下反应90 min,铁炭微电解出水COD的去除率在49.20%,色度去除率达到80%,BODs/COD值由0.248上升至0.436,可生化性提高;微电解出水在pH值为5,H2O2投加量为0.3%条件下反应60 min后,COD去除率可达84.1%,色度去除率达90%,BOD5/COD值上升至0.525;铁炭微电解- Fenton组合工艺COD的总去除率为87.26%.%The present paper is engaged in a study on the sewage residue from dyeing indigo-jeans by ferric-carbon micro-electrolysis and Fenton reagent. As is known, ferric-carbon micro-electrolysis and Fenton reagent are commonly used in pre- treating printing and dyeing sewage. For our research purpose, we have done a series of combined orthogonal experiments and the single factor experiment through the micro-electrolysis and Fenton and worked out the optimal operating conditions of COD and color removing effects. And, then, we have analyzed the mechanism of the affecting factors. The optimal conditions we have established through experiments can be stated as follows: the volume ratio of iron to carbon is equal to 2: 1, the influent pH value is 3, the ferric-carbon micro-electrolysis aeration time is 90 min. We have also enhanced the removal of COD and color, which can reach about 49% and 80% . When the treatment is over, we have found that the B0D5/C0D could be heightened from 0.248 to 0.436, with the biodegradability being improved. In addition, we have also found that Fe2 + and · OH could be generated at low cost by effective combination of micro-eSectrolysis and Fenton, which helps to overcome high cost and waste in Fenton reaction. Moreover, our study has also found the best operating conditions for Fenton reaction system: p

  18. Remoción de colorantes sintéticos mediante el proceso Fenton heterogéneo usando Fe2O3 soportado en carbón activado obtenido a partir de residuos de rosas

    Directory of Open Access Journals (Sweden)

    María Paula Castellanos

    2012-12-01

    Full Text Available To study the removal of dyes:reactive black 5 and crystal violet by the Fenton reaction using Fe2O3-catalysts (0-10% m/m of Fe supported on activated carbon obtained from rose remnants. The activated carbon was obtained from pyrolysis at 500 °C (1h followed by activation with NaOH (1:2 wt.. The support was classified using several chemical and physical techniques. Fe-catalysts were synthesized by incipient impregnation. Fenton and adsorption treatments were performed in a batch reactor, concentration of dye of 10 mgL-1, 0.25 mgmL-1 catalyst, pH = 3.7, 20 ± 2 ° C, 750 rpm and atmospheric pressure. The activated carbon used as support showed high basicity, presence of polar groups on the surface, high ash content (22.85% and oxygen (43.93% and was mostly of the microporous type with a BET surface area of 520 m2g-1. The maximum discoloration achieved for black reactive 5 was obtained with the catalyst of 3% Fe (98.33% after 180 min. while for the crystal violet it was obtained with the catalyst of 1% Fe (63.95% after 180 min. Discoloration by Fenton treatment is dependent on the Fe content, the particle size of the active site and the type of dye. The removal of reactive black 5 reached a maximum at 3% Fe while the crystal violet decreased by increasing Fe content. The treatment proposed in this paper is promising for the removal of synthetic dyes present in contaminated water.

  19. Optimization of Fenton oxidation pre-treatment for B. thuringiensis - based production of value added products from wastewater sludge.

    Science.gov (United States)

    Pham, T T H; Brar, S K; Tyagi, R D; Surampalli, R Y

    2010-08-01

    Fenton oxidation pretreatment was investigated for enhancement of biodegradability of wastewater sludge (WWS) which was subsequently used as substrate for the production of value- added products. The Response surface method with fractional factorial and central composite designs was applied to determine the effects of Fenton parameters on solubilization and biodegradability of sludge and the optimization of the Fenton process. Maximum solubilization and biodegradability were obtained as 70% and 74%, respectively at the optimal conditions: 0.01 ml H(2)O(2)/g SS, 150 [H(2)O(2)](0)/[Fe(2+)](0), 25 g/L TS, at 25 degrees C and 60 min duration. Further, these optimal conditions were tested for the production of a value added product, Bacillus thuringiensis (Bt) which is being used as a biopesticide in the agriculture and forestry sector. It was observed that Bt growth using Fenton oxidized sludge as a substrate was improved with a maximum total cell count of 1.63 x 10(9)CFU ml(-1) and 96% sporulation after 48 h of fermentation. The results were also tested against ultrasonication treatment and the total cell count was found to be 4.08 x 10(8)CFU ml(-1) with a sporulation of 90%. Hence, classic Fenton oxidation was demonstrated to be a rather more promising chemical pre-treatment for Bt - based biopesticide production using WWS when compared to ultrasonication as a physical pre-treatment.

  20. 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.

  1. Comparative temporal analysis of multiwalled carbon nanotube oxidation reactions: Evaluating chemical modifications on true nanotube surface

    Science.gov (United States)

    Pacheco, Flávia G.; Cotta, Alexandre A. C.; Gorgulho, Honória F.; Santos, Adelina P.; Macedo, Waldemar A. A.; Furtado, Clascídia A.

    2015-12-01

    The influence of extensive purification on oxidized multiwalled carbon nanotube surface composition was studied through the characterization and differentiation of the actual surface submitted to three oxidation methods: microwave-assisted acid oxidation, hydrogen peroxide reflux, and Fenton reaction. The oxidized samples were purified by a multi-step procedure including the sequential use of basic reflux and dispersion in dimethylformamide (DMF). The results showed a significant increase in the amount of oxidation debris with hydrogen peroxide and Fenton reaction times longer than 8 h and strong surface characteristic modification. With regard to sample purification, basic reflux led to a reduction in oxygenated group concentration of only 10% in the samples treated by acid oxidation. On the other hand, the subsequent use of DMF led to a further decrease in concentration of 39%, proving to be a more efficient method for the removal of oxidation debris.

  2. Investigation of the impacts of ethyl lactate based Fenton treatment on soil quality for polycyclic aromatic hydrocarbons (PAHs)-contaminated soils.

    Science.gov (United States)

    Gan, Suyin; Yap, Chiew Lin; Ng, Hoon Kiat; Venny

    2013-11-15

    This study aims to investigate the impacts of ethyl lactate (EL) based Fenton treatment on soil quality for polycyclic aromatic hydrocarbons (PAHs)-contaminated soils. Accumulation of oxygenated-polycyclic aromatic hydrocarbons (oxy-PAHs) was observed, but quantitative measurement on the most abundant compound 9,10-anthraquinone (ATQ) showed lower accumulation of the compound than that reported for ethanol (ET) based Fenton treatment. In general, as compared to conventional water (CW) based Fenton treatment, the EL based Fenton treatment exerted either a lower or higher negative impact on soil physicochemical properties depending on the property type and shared the main disadvantage of reduced soil pH. For revegetation, EL based Fenton treatment was most appropriately adopted for soil with native pH >/~ 6.2 in order to obtain a final soil pH >/~ 4.9 subject to the soil buffering capacity.

  3. 非均相光Fenton降解4-氯酚的研究%Degradation efficiency of 4-chlorophenol via heterogeneous photo-Fenton

    Institute of Scientific and Technical Information of China (English)

    王维明; 张冉; 王树涛; 刘婷; 尤宏

    2013-01-01

    制备了以Al2O3/TiO2为载体的负载型铁氧化物催化剂,对催化剂进行SEM、XRD、UV-vis-DRS和XPS分析,考察H2O2投加量、催化剂投加量、4-氯酚初始质量浓度对4-氯酚处理效果的影响,分析了非均相光Fenton体系的氧化机理.结果表明,所制备的负载型铁氧化物催化剂为α-FeOOH与γ-Fe2O3的混合物,其表面存在较多的颗粒和孔穴,吸附性强,具有很高的催化活性.H2O2、铁氧化物催化剂、紫外灯之间存在协同作用,所构成的非均相光Fenton体系对4-氯酚具有良好的去除效果.其反应机理为表面催化,催化剂表面的Fe(Ⅲ)在光照的作用下被还原为Fe(Ⅱ).在催化剂投加量为1 g/L,H2O2浓度为7.84mmol/L时,对4-氯酚的降解效果达到最佳,反应进行30 min后4-氯酚的去除率大于99%,反应1h矿化度可达91.4%.%This paper aims to introduce our preparation of catalysts loaded on Al2O3/TiO2 and the heterogeneous photo-Fenton reaction system we have established for the study of the degradation efficiency of the 4-chlorophenol. The catalysts we have prepared are characterized by SEM, XRD, by means of which we have investigated the effect of H2O2 dosage, along with the catalyst dosage and initial concentration of the 4-chlorophenol on 4-chlorophenol degradation needed. In addition, we have also done experiments to explore the oxidation mechanism of heterogeneous photo-Fenton system. The results of our research show that the ingredients of iron oxidate catalysts loaded on Al2O3/TiO2 were the mixture of α- FeOOH and γ - Fe2O3; and, as compared with Al2O3/TiO2 carrier, it has been found that there exist more surface particles and cavity on the catalyst surface, whose specific surface area proves to be wider for its adsorption, and, therefore, helps to enhance their catalytic activity. The heterogeneous photo-Fenton system we have established proves to be highly effective for degrading 4-chlorophenol. Furthermore, we have worked out the

  4. 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。

  5. Hydrometallurgical recovery of heavy metals from low grade automobile shredder residue (ASR): An application of advanced Fenton process (AFP).

    Science.gov (United States)

    Singh, Jiwan; Lee, Byeong-Kyu

    2015-09-15

    To investigate the leaching and recovery of heavy metals from low-grade automobile shredder residue (ASR), the effects of nitric acid (HNO3) and hydrogen peroxide (H2O2) concentrations, liquid/solid (L/S) ratio, leaching temperature and ASR particle size fractions on the heavy metal leaching rate were determined. The heavy metals were recovered by fractional precipitation and advanced Fenton process (AFP) at different pHs. The toxicity characteristic leaching procedure (TCLP) test was also performed in the residue remaining after heavy metal leaching to evaluate the potential toxicity of ASR. The heavy metal leaching efficiency was increased with increasing HNO3 and H2O2 concentrations, L/S ratio and temperature. The heavy metal leaching efficiencies were maximized in the lowest ASR size fraction at 303 K and L/S ratio of 100 mL/g. The kinetic study showed that the metal leaching was best represented by a second-order reaction model, with a value of R(2) > 0.99 for all selected heavy metals. The determined activation energy (kJ/mol) was 21.61, 17.10, 12.15, 34.50, 13.07 and 11.45 for Zn, Fe, Ni, Pb, Cd and Cr, respectively. In the final residue, the concentrations of Cd, Cr and Pb were under their threshold limits in all ASR size fractions. Hydrometallurgical metal recovery was greatly increased by AFP up to 99.96% for Zn, 99.97% for Fe, 95.62% for Ni, 99.62% for Pb, 94.11% for Cd and 96.79% for Cr. AFP is highly recommended for the recovery of leached metals from solution even at low concentrations.

  6. Removal of benzotriazole by heterogeneous photoelectro-Fenton like process using ZnFe2O4 nanoparticles as catalyst

    Institute of Scientific and Technical Information of China (English)

    Junfeng Wu; Wenhong Pu; Changzhu Yang; Man Zhang; Jingdong Zhang

    2013-01-01

    ZnFe2O4 nanoparticles (ZFNPs) were developed as catalyst for the degradation of benzotriazole (BTA) by heterogeneous photoelectro-Fenton (PE-Fenton) like process.ZFNPs were prepared by a co-precipitation process and then characterized with transmission electron microscopy (TEM),X-ray fluorescence (XRF),X-ray diffraction (XRD) and BET surface area.Using such ZFNPs as catalyst,the degradation of BTA was investigated.Due to the high catalytic activity of ZFNPs,PE-Fenton like process showed efficient degradation of BTA.The influencing factors such as pH,dosage of ZFNPs,applied potential and initial concentration of BTA were systematically investigated.Under the optimum conditions,91.2% of BTA was removed after 180 min treatment.

  7. Removal of benzotriazole by heterogeneous photoelectro-Fenton like process using ZnFe2O4 nanoparticles as catalyst.

    Science.gov (United States)

    Wu, Junfeng; Pu, Wenhong; Yang, Changzhu; Zhang, Man; Zhang, Jingdong

    2013-04-01

    ZnFe2O4 nanoparticles (ZFNPs) were developed as catalyst for the degradation of benzotriazole (BTA) by heterogeneous photoelectro-Fenton (PE-Fenton) like process. ZFNPs were prepared by a co-precipitation process and then characterized with transmission electron microscopy (TEM), X-ray fluorescence (XRF), X-ray diffraction (XRD) and BET surface area. Using such ZFNPs as catalyst, the degradation of BTA was investigated. Due to the high catalytic activity of ZFNPs, PE-Fenton like process showed efficient degradation of BTA. The influencing factors such as pH, dosage of ZFNPs, applied potential and initial concentration of BTA were systematically investigated. Under the optimum conditions, 91.2% of BTA was removed after 180 min treatment.

  8. In situ synthesis of nanostructured titania film on NiTi shape memory alloy by Fenton's oxidation method

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Fenton's oxidation method was successfully used to synthesize an ideal titania film in situ on NiTi shape memory alloy(SMA) for medical applications. Characterized with scanning electron microscopy, X-ray photoelectron spectroscopy, X-ray diffractometry, inductively coupled plasma mass spectrometry and electrochemical tests, it is found that the titania film produced by Fenton's oxidation method on NiTi SMA is nanostructured and has a Ni-free zone near its top surface, which results in a notable improvement in corrosion resistance and a remarkable decrease in leaching of harmful Ni ions from NiTi SMA in simulated body fluids. The improvement of effectiveness to corrosion resistance and the reduction in Ni release of NiTi SMA by Fenton's oxidation method are comparable to those by oxygen plasma immersion ion implantation reported earlier.

  9. Advanced Treatment of Pulping Medium Wastewater by Fenton-UV Combined Technology%Fenton-UV偶联深度处理制浆中段废水

    Institute of Scientific and Technical Information of China (English)

    蓝惠霞; 刘晓凤; 王乐乐

    2010-01-01

    采用Fenton-UV偶联时制浆中段废水进行深度处理.实验结果表明,Fenton氧化在UV照射下的处理效果明显好于无UV照射时的废水处理效果,尤其是大功率的UV(2000W)照射时,CODCr去除率和过氧化氢利用率可达80%以上.在紫外波长为365nm处,Fenton氧化处理效果优于波长为253.7nm时的效果.随着反应时间的增加,CODCr的去除率增大,在12min以后几乎保持稳定.CODCr去除率在pH为4时最好,高达88.4%.

  10. Fate of citalopram during water treatment with O3, ClO2, UV and fenton oxidation

    DEFF Research Database (Denmark)

    Hörsing, Maritha; Kosjek, Tina; Andersen, Henrik Rasmus;

    2012-01-01

    In the present study we investigate the fate of citalopram (CIT) at neutral pH using advanced water treatment technologies that include O3, ClO2 oxidation, UV irradiation and Fenton oxidation. The ozonation resulted in 80% reduction after 30 min treatment. Oxidation with ClO2 removed >90% CIT...... at a dosage of 0.1 mg L−1. During UV irradiation 85% reduction was achieved after 5 min, while Fenton with addition of 14 mg L−1 (Fe2+) resulted in 90% reduction of CIT. During these treatment experiments transformation products (TPs) were formed from CIT, where five compounds were identified by using high...

  11. Ascorbate-Promoted Surface Iron Cycle for Efficient Heterogeneous Fenton Alachlor Degradation with Hematite Nanocrystals.

    Science.gov (United States)

    Huang, Xiaopeng; Hou, Xiaojing; Jia, Falong; Song, Fahui; Zhao, Jincai; Zhang, Lizhi

    2017-03-15

    This study reports the H2O2 activation with different hematite nanocrystals and ascorbate ions for the herbicide alachlor degradation at pH 5. We found that hematite nanoplates (HNPs) exposed with {001} facets exhibited better catalytic performance than hematite nanocubes (HNCs) exposed with {012} facets, which was attributed to the formation of inner-sphere iron-ascorbate complexes on the hematite facets. The 3-fold undercoordination Fe cations of {001} facet favors the formation of inner-sphere iron-ascorbate complexes, while the 5-fold undercoordination Fe cations of {012} facet has stereo-hindrance effect, disfavoring the complex formation. The surface area normalized alachlor degradation rate constant (23.3 × 10(-4) min(-1) L m(-2)) of HNPs-ascorbate Fenton system was about 2.6 times that (9.1 × 10(-4) min(-1) L m(-2)) of HNCs-ascorbate counterpart. Meanwhile, the 89.0% of dechlorination and 30.0% of denitrification in the HNPs-ascorbate Fenton system were also significantly higher than those (60.9% and 13.1%) of the HNCs-ascorbate one. More importantly, the reductive dissolution of hematite by ascorbate was strongly coupled with the subsequent H2O2 decomposition by surface bound ferrous ions through surface iron cycle on the hematite facets in the hematite-ascorbate Fenton systems. This coupling could significantly inhibit the conversion of surface bound ferrous ions to dissolved ones, and thus account for the stability of hematite nanocrystals. This work sheds light on the internal relationship between iron geochemical cycling and contaminants degradation, and also inspires us to utilize surface iron cycle of widely existent hematite for environmental remediation.

  12. Preparation of immobilized coating Fenton-like catalyst for high efficient degradation of phenol.

    Science.gov (United States)

    Wang, Jiankang; Yao, Zhongping; Wang, Yajing; Xia, Qixing; Chu, Huiya; Jiang, Zhaohua

    2017-03-06

    In this study, solid acid amorphous Fe3O4/SiO2 ceramic coating decorated with sulfur on Q235 carbon steel as Fenton-like catalyst for phenol degradation was successfully prepared by plasma electrolytic oxidation (PEO) in silicate electrolyte containing Na2S2O8 as sulfur source. The surface morphology and phase composition were characterized by SEM, EDS, XRD and XPS analyses. NH3-TPD was used to evaluate surface acidity of PEO coating. The results indicated that sulfur decorated amorphous Fe3O4/SiO2 ceramic coatings with porous structure and higher acid strength had the similar pore size and the surface became more and more uneven with the increase of Na2S2O8 in the silicate electrolyte. The Fenton-like catalytic activity of sulfur decorated PEO coatings was also evaluated. In contrast to negligible catalytic activity of sulfur undecorated PEO coating, catalytic activity of sulfur decorated PEO coating was excellent and PEO coating prepared with 3.0 g Na2S2O8 had the highest catalytic activity which could degrade 99% of phenol within 8 min under circumneutral pH. The outstanding performance of sulfur decorated PEO coating was attributed to strong acidic microenvironment and more Fe(2+) on the surface. The strong acid sites played a key factor in determining catalytic activity of catalyst. In conclusion, rapid phenol removal under circumneutral pH and easier separation endowed it potential application in wastewater treatment. In addition, this strategy of preparing immobilized solid acid coating could provide guidance for designing Fenton-like catalyst with excellent catalytic activity and easier separation.

  13. 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.

  14. Treatment of pesticide wastewater by moving-bed biofilm reactor combined with Fenton-coagulation pretreatment

    Energy Technology Data Exchange (ETDEWEB)

    Chen Sheng [School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090 (China)]. E-mail: hitchensheng@126.com; Sun Dezhi [School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090 (China); Chung, J.-S. [School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090 (China); Department of Chemical Engineering, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of)

    2007-06-01

    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 Fe{sup 2+} concentration of 40 mmol/L and H{sub 2}O{sub 2} 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){sub 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 (BOD{sub 5}) 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/(m{sup 2} carrier day)

  15. Treatment of pesticide wastewater by moving-bed biofilm reactor combined with Fenton-coagulation pretreatment.

    Science.gov (United States)

    Chen, Sheng; Sun, Dezhi; Chung, Jong-Shik

    2007-06-01

    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 Fe(2+) concentration of 40 mmol/L and H(2)O(2) 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, 3.2g/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 (BOD(5)) 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/(m(2)carrierday).

  16. Treatment of pesticide rinsate towards reuse by photosensitized Fenton-like process.

    Science.gov (United States)

    Kuo, W S; Ho, Y Y

    2010-01-01

    A Fenton-like process with combination of dye has been used to enhance the treatment of carbofuran (2,3-dihydro-2,2-dimethylbenzofuran -7-yl methylcarbamate) pesticide rinsate. Results showed that as compared to Fenton-like process, this photosensitization Fenton-like process improved the degradation efficiency of carbofuran rinsate significantly. Among the conditions studied, the optimum dosage for the complete destruction of carbofuran molecular structure was found under a [H2O2]0/[Fe3+]0 ratio of 30-35 and a [Dye]0/[Fe3+]0 ratio of 2%, respectively, after an irradiance of 500 W/m2 for 20 min. As a result, the COD degradation efficiency of rinsate could be promoted from 37.1 to 61.2% and 66.0% by an addition of methylene blue (MB) and alizarin red S (ARS), respectively. Nevertheless, ARS showed a much more effective acceleration effect on the mineralization and microtoxicity reduction of carbofuran than MB. A mineralization efficiency of 57.2% and a microtoxicity reduction of 90% could be achieved with the addition of ARS. Because of its quinone structure unit, the dye ARS could play a role like hydroquinone to recycle Fe2+ from Fe3+, resulting in one more catalytic effect on the reduction of Fe3+ and thus the mineralization and microtoxicity reduction of carbofuran was greatly promoted in the presence of ARS. In addition, it was found that carbofuran molecules could be decomposed quickly to lower-molecular-weight intermediates and even mineralized by attacking of hydroxyl radicals. Carbofuran was found to be decomposed to carbofuran phenol, 3-oxo carbofuran phenol, and 3-hydroxyl carbofuran phenol initially, and then further be degraded to smaller molecules, such as NO3-, CH3COOH, (COOH)2 and CO2. Accordingly, it was believed that the Fenton-like process along with the aid of a photosensitizer, such as ARS, under an appropriate ratio could be a feasible and potential technology for the treatment of pesticide rinsate.

  17. A Fenton-like degradation mechanism for 1,4-dioxane using zero-valent iron (Fe0) and UV light.

    Science.gov (United States)

    Son, Hyun-Seok; Im, Jong-Kwon; Zoh, Kyung-Duk

    2009-03-01

    In this study, the degradation mechanism of 1,4-dioxane using zero-valent iron (Fe0) in the presence of UV light was investigated kinetically. The degradation of 1,4-dioxane in Fe0-only, photolysis, and combined Fe0 and UV reactions followed the kinetics of a pseudo-first-order model. The degradation rate constant (19 x 10(-4)min(-1)) in the combined reaction with UV-C (4.2 mW cm(-2)) and Fe0 (5 mg L(-1)) was significantly enhanced compared to Fe0-only (4.8 x 10(-4) min(-1)) and photolytic reactions (2.25 x 10(-4)min(-1)), respectively. The removal efficiency of 1,4-dioxane in combined reaction with Fe0 and UV within 4 h was enhanced by increasing UV intensity at UV-C region (34% at 4.2 mW cm(-2) and 89% at 16.9 mW cm(-2)) comparing with the removal in the combined reaction with Fe0 and UV-A (29% at 2.1 mW cm(-2), and 33% at 12.6 mW cm(-2)). It indicates that 1,4-dioxane was degraded mostly by OH radicals in the combined reaction. The degradation patterns in both Fe(0)-only and combined reactions were well fitted to the Langmuir-Hinshelwood model, implying that adsorption as well as the chemical reaction occurred. The transformation of Fe0 to Fe2+ and Fe3+ was observed in the Fe0-only and combined reactions, and the transformation rate of Fe0 was improved by UV irradiation. Furthermore, the reduction of Fe3+ was identified in the combined reaction, and the reduction rate was enhanced by an increase of UV energy. Our study demonstrated that the enhancement of 1,4-dioxane removal rate occurred via an increased supply of OH radicals from the Fenton-like reaction induced by the photolysis of Fe0 and H2O, and with producing less sludge.

  18. The investigation of degradation and mineralization of high concentrations of formaldehyde in an electro-Fenton process combined with the biodegradation.

    Science.gov (United States)

    Moussavi, Gholamreza; Bagheri, Amir; Khavanin, Ali

    2012-10-30

    This study was done to evaluate the degradation and mineralization of formaldehyde (≈ 8000 mg/L) in an electro-Fenton process (EFP) in combination with biodegradation. In the first step, the influence of several important parameters including solution pH, current density, H(2)O(2) concentration, and reaction time were tested on the efficiency of the EFP in degradation and mineralization of formaldehyde in a concentrated solution. The optimum pH and current density was found to be around 10 and 8.5 mA/cm(2), respectively. The formaldehyde degradation in the EFP increased with an increased H(2)O(2) concentration. Under optimum pH and current density, the complete degradation and 51% mineralization of formaldehyde was attained in the EFP using a H(2)O(2) concentration of 10mM/min at a short reaction time of 6 min. The biodegradation of the effluent of EFP under optimum conditions (complete formaldehyde removal) was also tested. The results demonstrated that the concentration of the EFP effluent could be efficiently reduced in the bioreactor to below 50mg/L after a biodegradation time of 16d. Accordingly, results showed that EFP was a very efficient process for degradation and mineralization of a high concentration of formaldehyde so that its effluent could be efficiently post-treated with a biological process.

  19. Degradation of polycyclic aromatic hydrocarbons (PAHs) in contaminated soils by Fenton's reagent: a multivariate evaluation of the importance of soil characteristics and PAH properties.

    Science.gov (United States)

    Jonsson, Sofia; Persson, Ylva; Frankki, Sofia; van Bavel, Bert; Lundstedt, Staffan; Haglund, Peter; Tysklind, Mats

    2007-10-01

    In this study, we investigated how the chemical degradability of polycyclic aromatic hydrocarbons (PAHs) in aged soil samples from various contaminated sites is influenced by soil characteristics and by PAH physico-chemical properties. The results were evaluated using the multivariate statistical tool, partial least squares projections to latent structures (PLS). The PAH-contaminated soil samples were characterised (by pH, conductivity, organic matter content, oxide content, particle size, specific surface area, and the time elapsed since the contamination events, i.e. age), and subjected to relatively mild, slurry-phase Fenton's reaction conditions. In general, low molecular weight PAHs were degraded to a greater extent than large, highly hydrophobic variants. Anthracene, benzo(a)pyrene, and pyrene were more susceptible to degradation than other, structurally similar, PAHs; an effect attributed to the known susceptibility of these compounds to reactions with hydroxyl radicals. The presence of organic matter and the specific surface area of the soil were clearly negatively correlated with the degradation of bi- and tri-cyclic PAHs, whereas the amount of degraded organic matter correlated positively with the degradation of PAHs with five or six fused rings. This was explained by enhanced availability of the larger PAHs, which were released from the organic matter as it degraded. Our study shows that sorption of PAHs is influenced by a combination of soil characteristics and physico-chemical properties of individual PAHs. Multivariate statistical tools have great potential for assessing the relative importance of these parameters.

  20. Degradation of p-Nitrophenol using magnetic Fe(0)/Fe3O4/Coke composite as a heterogeneous Fenton-like catalyst.

    Science.gov (United States)

    Wan, Dong; Li, Wenbing; Wang, Guanghua; Lu, Lulu; Wei, Xiaobi

    2017-01-01

    A Coke supported Fe3O4 and Fe(0) composite (Fe(0)/Fe3O4/Coke) was prepared for the first time with the aim of evaluating its ability to be used as heterogeneous catalyst for the Fenton degradation of p-Nitrophenol (p-NP). A four factor Box-Behnken design (BBD) coupled with response surface methodology (RSM) was applied to evaluate the effects of several operating parameters, namely Fe(0)/Fe3O4/Coke dosage, reaction temperature, initial pH and H2O2 concentration, on the removal efficiency of p-NP. A significant quadratic model (p-valuep-NP (100mg/L) conversion and 81% of COD removal were achieved after 120min of reaction time, respectively, under the optimum conditions, which agreed well with the modeling prediction. The recyclability of Fe(0)/Fe3O4/Coke was also investigated after three successive runs, in which p-NP degradation performances showed a slight difference with the first oxidation cycle with an acceptable iron leaching. Moreover, according to the main intermediate products identified by gas chromatography-mass spectrometry (GC-MS), a possible pathway of p-NP degradation was proposed based on hydrogen radicals ([H]) or hydroxyl radicals (•OH) mechanism.

  1. 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.

  2. Study on the treatment of trichlorfon pesticides wastewater with UV-TiO2-Fenton-Activated carbon%UV-TiO2-Fenton-活性炭处理敌百虫农药废水的研究

    Institute of Scientific and Technical Information of China (English)

    朱丹; 王瑛瑛; 廖绍华; 赵磊

    2013-01-01

    Taking the trichlorfon wastewater as test material, the treatment effects of UV-TiO2-Fenton -Activated Carbon were studied. The result shows that treatment with UV has a great COD removal effect compa-ring to other treatments. The COD of trichlorfon wastewater would decrease from 16 675. 7 mg/L to 6 987. 1 mg/L by UV-TiO2-Fenton-Activated Carbon. The COD removal was up to 58. 1 % .%以敌百虫农药废水为研究对象,研究了UV-TiO2-Fenton-活性炭对敌百虫农药废水单独使用及复合联用的处理效果,结果表明:各方法单独使用时,UV光照对敌百虫农药废水COD的去除效果最好.将UV-TiO2-Fenton-活性炭复合联用处理敌百虫农药废水时,COD由16 675.7 mg/L变为6987.1 mg/L,COD去除率达58.1%.

  3. Fenton-BAF-RO工艺处理电镀前处理废水并回用%Treatment and Reuse of Electroplating Pre-treatment Wastewater by Fenton/BAF/RO Membrane Technology

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    Pre-treatment wastewater is an important part of the plating wastewater. It has higher COD but with relatively larger reuse potential. The technology of Fenton-BAF-RO membrane separation process was used to treat electroplating Pre-treatment wastewater from a plant in Guangdong province, the results show that the pre-treatment wastewater can be advanced treated and reused effectively by this technology, and by concentrated water recirculation, zero emission was achieved. Fenton-BAF process ensure the stable operation of the RO system.%  前处理废水是电镀废水的重要组成部分,COD较高但回用潜力相对较大。采用Fenton-BAF-RO膜分离工艺处理广东省某厂电镀前处理废水,运行结果表明,该工艺可有效实现电镀前处理废水的深度处理及回用,并且通过浓水回流达到零排放,Fenton-BAF 工艺保证了 RO 系统的稳定运行。

  4. Research on Treating Dye Wastewater by Fenton Reagent%Fenton试剂对染料废水的降解脱色作用研究

    Institute of Scientific and Technical Information of China (English)

    杨威; 孔德骞; 车春波; 刘丹

    2009-01-01

    In order to research the degradation efficiency of Fenton method on some non-biodegradable organic pollutant and the factors that af-fect the degradation process, the effects d pH,dosages of H2O2 and FeSO4, reaction time,temperature on decolouration efficiency and COD removal efficiency of the dyes wastewater simulated by methyl orange solution were studied. The results showed that Fenton reagent could remove the color and COD of this dye wastewater effectively with color and COD removals of 99.66 % and 88% respectively when the concentration of dye was 200 mg/L, pH=4,temperature was 20℃,the dosages of H2O2 and FeSO4·7H2O were 0.6 mL/L and 200mg/L,and reaction time was 60min.%为了进一步探讨Fenton法对某些难降解有机物的降解效果,研究影响降解的诸多因素,以甲基橙模拟染料废水为研究对象,以色度和COD去除率为检测指标,研究了Fenton反应中pH值、H2O2浓度、Fe2+离子浓度、反应时间、温度对甲基橙模拟染料废水脱色率及COD去除率的影响规律.结果表明:Fenten试剂可有效地去除甲基橙模拟染料废水中的色度和COD.染料浓度为200mg/L时,在pH=4、20℃、H2O2=(浓度为30%)投量为0.6mL/L、硫酸亚铁投量为200mg/L时,反应60min,甲基橙模拟染料废水的色度去除率可以达到99.66%,COD的去除率可达88%.

  5. 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.

  6. Research on Degradation of Starch Wastewater by Ultrasonic-Fenton Oxidation Process%超声-Fenton 高级氧化降解淀粉废水的研究

    Institute of Scientific and Technical Information of China (English)

    任百祥; 刘伟; 刘夏

    2014-01-01

    采用超声与 Fenton 高级氧化技术联合处理实际高浓度玉米淀粉废水,超声波与 Fenton 试剂联合作用时,在超声波的作用下,极短时间(<10μs)内形成空化气泡会发生空化现象.由于玉米淀粉浓度较高,在超声作用时有机物更容易发生碰撞,产生较多的自由基,使玉米淀粉废水中的有机物得到降解.最终达到较好的去除效果.通过单独超声实验得到最佳的超声时间为150 min,超声波频率为45 kHz,超声波功率为200 W,pH 值为3;通过超声与超声-H2 O2联合的对比实验,得出 H2 O2最佳投加量为40 mmol/ L;通过单独加入 Fenton 试剂与超声-Fenton 联合的对比实验,得出 FeSO4最佳投加量为8 mmol/ L.在最佳参数条件下,超声-Fenton 法处理高浓度玉米淀粉废水,其 COD 去除率可达到92%.%Corn starch wastewater belongs to high concentration organic wastewater. This experiment uses the ultrasound with senior Fenton oxidation technology processing. With the joint action of ultrasound and Fenton reagent,under the action of ultrasonic wave,cavitation phenomenon will happen with the formation of cavitation bubble in a very short time( < 10 μs). Because corn starch concentration is higher,in the ultrasonic action, organic matter are more likely to collide,then produce more free radicals which make the organic matter of the corn starch wastewater degraded. Ultimately it achieves better removal effect. Through the single ultrasonic experiment,the best ultrasonic time of 150 min,ultrasonic frequency of 45 kHz,ultrasonic power of 200 W,pH value of 3 are obtained. By ultrasound and ultrasound-H2 O2 joint contrast experiment,the optimum dosing amount of H2 O2 is 40 mmol/ L. Through a separate join Fenton reagent and the contrast experiment of ultrasonic-Fenton joint,the optimum dosing amount of FeSO4 is 8 mmol/ L. Under the condition of optimum parameters,using ultrasonic-Fenton treatment of high

  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. Solar photo-Fenton optimisation in treating carbofuran-contaminated water

    Directory of Open Access Journals (Sweden)

    Manuel Alejandro Hernández-Shek

    2012-04-01

    Full Text Available Box-Benkhen design response-surface methodology was developed to optimise photo-Fenton degradation of carbofuran (C12H15NO3 by using a compound parabolic collector pilot plant. The four variables considered in Box-Benkhen design model included carbofuran degradation percentage, initial carbofuran concentration, hydrogen peroxide [H2O2] concentration and iron [Fe2+] concentration. Degradation was monitored by using total organic carbon concentration and high-performance liquid chromatography. A 93.2 mg l-1 carbofuran concentration was completely degraded in t30W = 15 min with 17.1 mg l-1 Fe2+ and 121.6 mg l-1 H2O2. Photo-Fenton degradation led to 76.7% mineralisation. Biodegradability during optimisation was evaluated by using the BOD5/COD ratio; this value increased from 0.04 at the beginning of the process to 0.52 in t30W = 20 min, thereby showing the effectiveness of using biological treatments.

  9. Applicability of an electrochemical Fenton-type process to actual wastewater treatment.

    Science.gov (United States)

    Kishimoto, Naoyuki; Kitamura, Takuya; Nakamura, Yu

    2015-01-01

    The applicability of an electrochemical Fenton-type process (EF-HOCl-ReFe) to the treatment of three actual wastewaters, namely wastewater from an automobile factory (automobile wastewater), metal scrap-cleansing wastewater, and municipal wastewater, is discussed in this research. The EF-HOCl-ReFe successfully removed the chemical oxygen demand (COD) from automobile wastewater pre-treated by a coagulation process without any inhibition. The apparent current efficiency reached 86%, 46% of which was ascribed to the electrochemical Fenton-type mechanism. The metal scrap-cleansing wastewater had a yellow colour and high concentrations of COD (6550 mg/L) and Cl(-) (1560 mM). The EF-HOCl-ReFe could achieve almost complete COD removal and decolourization after 48 h of treatment, although a temporary intensification of colour was observed before the decolourization. The EF-HOCl-ReFe was also effective in the removal of 1,4-dioxane from municipal wastewater pre-treated by activated sludge and coagulation processes, which were unable to remove 1,4-dioxane. The 1,4-dioxane removal efficiency after 30 min of treatment reached 68.5%. Thus, the EF-HOCl-ReFe was applicable to the treatment of these actual wastewaters.

  10. Coupling solar photo-Fenton and biotreatment at industrial scale: Main results of a demonstration plant

    Energy Technology Data Exchange (ETDEWEB)

    Malato, Sixto [Plataforma Solar de Almeria-CIEMAT, Crta. Senes km 4, 04200 Tabernas, Almeria (Spain)]. E-mail: Sixto.malato@psa.es; Blanco, Julian [Plataforma Solar de Almeria-CIEMAT, Crta. Senes km 4, 04200 Tabernas, Almeria (Spain); Maldonado, Manuel I. [Plataforma Solar de Almeria-CIEMAT, Crta. Senes km 4, 04200 Tabernas, Almeria (Spain); Oller, Isabel [Plataforma Solar de Almeria-CIEMAT, Crta. Senes km 4, 04200 Tabernas, Almeria (Spain); Gernjak, Wolfgang [Plataforma Solar de Almeria-CIEMAT, Crta. Senes km 4, 04200 Tabernas, Almeria (Spain); Perez-Estrada, Leonidas [Plataforma Solar de Almeria-CIEMAT, Crta. Senes km 4, 04200 Tabernas, Almeria (Spain)

    2007-07-31

    This paper reports on the combined solar photo-Fenton/biological treatment of an industrial effluent (initial total organic carbon, TOC, around 500 mg L{sup -1}) containing a non-biodegradable organic substance ({alpha}-methylphenylglycine at 500 mg L{sup -1}), focusing on pilot plant tests performed for design of an industrial plant, the design itself and the plant layout. Pilot plant tests have demonstrated that biodegradability enhancement is closely related to disappearance of the parent compound, for which a certain illumination time and hydrogen peroxide consumption are required, working at pH 2.8 and adding Fe{sup 2+} = 20 mg L{sup -1}. Based on pilot plant results, an industrial plant with 100 m{sup 2} of CPC collectors for a 250 L/h treatment capacity has been designed. The solar system discharges the wastewater (WW) pre-treated by photo-Fenton into a biotreatment based on an immobilized biomass reactor. First, results of the industrial plant are also presented, demonstrating that it is able to treat up to 500 L h{sup -1} at an average solar ultraviolet radiation of 22.9 W m{sup -2}, under the same conditions (pH, hydrogen peroxide consumption) tested in the pilot plant.

  11. Coupling solar photo-Fenton and biotreatment at industrial scale: main results of a demonstration plant.

    Science.gov (United States)

    Malato, Sixto; Blanco, Julián; Maldonado, Manuel I; Oller, Isabel; Gernjak, Wolfgang; Pérez-Estrada, Leonidas

    2007-07-31

    This paper reports on the combined solar photo-Fenton/biological treatment of an industrial effluent (initial total organic carbon, TOC, around 500mgL(-1)) containing a non-biodegradable organic substance (alpha-methylphenylglycine at 500mgL(-1)), focusing on pilot plant tests performed for design of an industrial plant, the design itself and the plant layout. Pilot plant tests have demonstrated that biodegradability enhancement is closely related to disappearance of the parent compound, for which a certain illumination time and hydrogen peroxide consumption are required, working at pH 2.8 and adding Fe(2+)=20mgL(-1). Based on pilot plant results, an industrial plant with 100m(2) of CPC collectors for a 250L/h treatment capacity has been designed. The solar system discharges the wastewater (WW) pre-treated by photo-Fenton into a biotreatment based on an immobilized biomass reactor. First, results of the industrial plant are also presented, demonstrating that it is able to treat up to 500Lh(-1) at an average solar ultraviolet radiation of 22.9Wm(-2), under the same conditions (pH, hydrogen peroxide consumption) tested in the pilot plant.

  12. Solar photo-Fenton as finishing step for biological treatment of a pharmaceutical wastewater.

    Science.gov (United States)

    Sirtori, C; Zapata, A; Oller, I; Gernjak, W; Agüera, A; Malato, S

    2009-02-15

    Remediation of pharmaceutical wastewater, containing nalidixic acid (NXA; 38 mg/L), a quinolone antibacterial agent commonly used in human and veterinary medicine, and characterized as having mainly 725 mg/L dissolved organic carbon (DOC), 3400 mg/L chemical oxygen demand, and around 4 g/L NaCl, was studied. A prior biodegradability study (Zahn-Wellens test) had demonstrated that the matrix was biodegradable after a rather long biomass adaptation period. After 4 days of treatment in an immobilized biomass reactor (IBR), 96% of the original DOC was removed by the biological treatment however, more than 50% of NXA was adsorbed on the biomass. As development of chronic toxicity in the IBR is possible after long exposure to NXA, adsorption and biomass stability during continuous exposure to NXA were studied in different cycles for one month. Afterthe biotreatment, the effluent was treated by solar photo-Fenton. Total degradation of NXA and reduction in toxicity were observed. The intermediates formed during degradation by biotreatment and subsequent photo-Fenton were studied by liquid chromatography-time-of-flight mass spectrometry.

  13. Influence of pretreatment with Fenton's reagent on biogas production and methane yield from lignocellulosic biomass.

    Science.gov (United States)

    Michalska, Karina; Miazek, Krystian; Krzystek, Liliana; Ledakowicz, Stanisław

    2012-09-01

    Biomass from Miscanthus giganteus, Sida hermaphrodita and Sorghum Moensch was treated with Fenton's reagent for 2 hours under optimal conditions (pH=3, mass ratio of [Fe(2+)]:[H(2)O(2)] equals 1:25 for Miscanthus and Sorghum and 1:15 for Sida). The degrees of delignification were 30.3%, 62.3% and 48.1% for the three plant species, respectively. The volatile fatty acids concentration after chemical pretreatment was high enough for production of biogas with a high methane content. Combined chemical oxidation and enzymatic hydrolysis with cellulase and cellobiase led to glucose contents of above 4 g/L. Among the tested plants, the highest biogas production (25.2 Ndm(3)/kg TS fed) with a 75% methane content was obtained with Sorghum Moensch. The results of the three-step process of biomass degradation show the necessity of applying a chemical pretreatment such as oxidation with Fenton's reagent. Moreover, the coagulation of residual Fe(3+) ions is not required for high biogas production.

  14. Fenton工艺深度处理制浆造纸废水的常见问题及其解决措施%The problems and its solutions in advanced treatment of paper mill waste water by Fenton process

    Institute of Scientific and Technical Information of China (English)

    赵全伟

    2014-01-01

    通过调节Fenton试剂的投加量及反应pH探讨不同加药量及反应条件对二沉池出水CODCr去除效率的影响。结果表明:当硫酸亚铁和双氧水的投加量分别为0.9g/L和0.11g/L,反应pH为3.0,反应时间为15min时,CODCr的去除效率最高可达85%。并对在实际运行过程中存在的问题进行讨论,提出解决措施,以期为高级氧化技术在废水的深度处理提供相关经验。%The effect of different conditions and different chemicals dosage on CODCr removal rate in eflfuent of the secondary sedimentation pool was studied by adjustment of Fenton agent dosage and pH value. The results show that when the mass concentrations of ferrous sulfate and hydrogen peroxide are 0.9g/l and 0.11g/l, respectively, the reaction pH is 3.0 and reaction time is 15min, the removal rate of CODCr can be up to 85%. In this article were also discussed the problems in the actual operation with the Fenton reaction process and put forward the solving solutions to provide relevant references for the practical application with advanced oxidation technology in waste water advance treatment.

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

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Carmen S.D. [LSRE - Laboratory of Separation and Reaction Engineering, Department of Chemical Engineering, Faculty of Engineering, University of Porto, R. Dr. Roberto Frias, s/n, 4200-465 Porto (Portugal); Madeira, Luis M. [LEPAE - Laboratory for Process, Environmental and Energy Engineering, Department of Chemical Engineering, Faculty of Engineering, University of Porto, R. Dr. Roberto Frias, s/n, 4200-465 Porto (Portugal); Boaventura, Rui A.R., E-mail: bventura@fe.up.pt [LSRE - Laboratory of Separation and Reaction Engineering, Department of Chemical Engineering, Faculty of Engineering, University of Porto, R. Dr. Roberto Frias, s/n, 4200-465 Porto (Portugal)

    2009-12-30

    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, BOD{sub 5} 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.

  16. 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.

  17. Economic evaluation of a combined photo-Fenton/MBR process using pesticides as model pollutant. Factors affecting costs.

    Science.gov (United States)

    Sánchez Pérez, José Antonio; Román Sánchez, Isabel María; Carra, Irene; Cabrera Reina, Alejandro; Casas López, José Luis; Malato, Sixto

    2013-01-15

    The aim of this paper is to carry out an economic assessment on a solar photo-Fenton/MBR combined process to treat industrial ecotoxic wastewater. This study focuses on the impact of the contamination present in wastewater, the photochemical oxidation, the use of an MBR as biological process and the plant size on operating and amortization costs. As example of ecotoxic pollutant, a mixture of five commercial pesticides commonly used in the Mediterranean area has been used, ranging from 500 mg/L to 50mg/L, expressed as dissolved organic carbon concentration. The economic evaluation shows that (i) the increase in pollution load does not always involve an increase in photo-Fenton costs because they also depend on organic matter mineralization; (ii) the use of an MBR process permits lower photochemical oxidation requirements than other biological treatments, resulting in approximately 20% photo-Fenton cost reduction for highly polluted wastewater; (iii) when pollution load decreases, the contribution of reactant consumption to the photo-Fenton process costs increase with regard to amortization costs; (iv) 30% total cost reduction can be gained treating higher daily volumes, obtaining competitive costs that vary from 1.1-1.9 €/m(3), depending on the pollution load.

  18. Effect of a solar Fered-Fenton system using a recirculation reactor on biologically treated landfill leachate.

    Science.gov (United States)

    Ye, Zhihong; Zhang, Hui; Yang, Lin; Wu, Luxue; Qian, Yue; Geng, Jinyao; Chen, Mengmeng

    2016-12-05

    The effects of electrochemical oxidation (EO), Fered-Fenton and solar Fered-Fenton processes using a recirculation flow system containing an electrochemical cell and a solar photo-reactor on biochemically treated landfill leachate were investigated. The most successful method was solar Fered-Fenton which achieved 66.5% COD removal after 120min treatment utilizing the optimum operating conditions of 47mM H2O2, 0.29mM Fe(2+), pH0 of 3.0 and a current density of 60mA/cm(2). The generation of hydroxyl radicals (OH) are mainly from Fered-Fenton process, which is enhanced by the introduction of renewable solar energy. Moreover, Fe(2+)/chlorine and UV/chlorine processes taking place in this system also result in additional production of OH due to the relatively high concentration of chloride ions contained in the leachate. The energy consumption was 74.5kWh/kg COD and the current efficiency was 36.4% for 2h treatment. In addition, the molecular weight (MW) distribution analysis and PARAFAC analysis of excitation emission matrix (EEM) fluorescence spectroscopy for different leachate samples indicated that the organics in the leachate were significantly degraded into either small molecular weight species or inorganics.

  19. 利用固体类Fenton试剂降解五氯酚的探讨%Decontamination of Pentachlorophenol Using Solid Fenton-like Reagents

    Institute of Scientific and Technical Information of China (English)

    杨冰; Pignatello Joseph J; 曲东

    2015-01-01

    In this study, four types of solid peroxides(calcium peroxide, CP;sodium perborate, SPB;sodium percarbonate, SPC;urea hydro-gen peroxide, UHP), H2O2, and two iron sources[Fe3(PO4)2 and FeSO4] were used to investigate pentachlorophenol(PCP)degradation in sil-ica sand slurries by Fenton-like reactions in incubation experiment. The main factors influencing the effectiveness and sustainability of ac-tive components of Fenton-like reagents were explored. Adding CP, SPB or SPC quickly increased solution pH to 10~12 and significantly inhibited Fe(Ⅱ)effectiveness. However, H2O2 or UHP showed little effect on solution pH. The rate of PCP degradation was 22.0%, 14.6%, 17.3%, 86.5%and 83.8%, respectively, for CP, SPB, SPC, UHP and H2O2 with FeSO4 as Fe(Ⅱ)source in 24 hours, and no obvious further PCP degradation was observed from 24 to 48 hours. For treatments with Fe3(PO4)2 as a steady Fe(Ⅱ)source, however, PCP showed contin-uous degradation during 20 d experimental period. The PCP degradation rate on the 20th day was 30.1%, 13.6%, 8.6%and 37.0%, for CP, SPB, SPC and UHP, respectively. Applying H2O2 resulted in 55.6%degradation of PCP in 16 days in Fe3(PO4)2 Fenton reaction. The pre-sent results show that pH buffer is required for a better decontamination performance when using alkaline-inducing solid peroxides(CP, SPB and SPC)as Fenton-like reagents. UHP might be an alternative for H2O2. Solid Fenton-like reagents significantly extend active compo-nents′life time from less than 24 hours to more than 20 days, thus possessing greater potential for soil contamination remediation.%采用四种固体过氧化物(过氧化钙,CP;过硼酸钠,SPB;过碳酸钠,SPC;过氧化尿素,UHP)以及 H2O2和两种铁源[(Fe3(PO4)2和FeSO4],通过室内模拟试验,研究不同过氧化物和Fe(Ⅱ)源组合构成的(类)Fenton反应对石英砂中五氯酚(PCP)的降解能力,探讨了影响类Fenton试剂活性成分有效性和持续性的

  20. Reduction of clarithromycin and sulfamethoxazole-resistant Enterococcus by pilot-scale solar-driven Fenton oxidation.

    Science.gov (United States)

    Karaolia, Popi; Michael, Irene; García-Fernández, Irene; Agüera, Ana; Malato, Sixto; Fernández-Ibáñez, Pilar; Fatta-Kassinos, Despo

    2014-01-15

    The presence of pathogenic antibiotic-resistant bacteria in aquatic environments has become a health threat in the last few years. Their presence has increased due to the presence of antibiotics in wastewater effluents, which are not efficiently removed by conventional wastewater treatments. As a result there is a need to study the possible ways of removal of the mixtures of antibiotics present in wastewater effluents and the antibiotic-resistant bacteria, which may also spread the antibiotic resistance genes to other bacterial populations. In this study the degradation of a mixture of antibiotics i.e. sulfamethoxazole and clarithromycin, the disinfection of total enterococci and the removal of those resistant to: a) sulfamethoxazole, b) clarithromycin and c) to both antibiotics have been examined, along with the toxicity of the whole effluent mixture after treatment to the luminescent aquatic bacterium Vibrio fischeri. Solar Fenton treatment (natural solar driven oxidation) using Fenton reagent doses of 50 mg L(-1) of hydrogen peroxide and 5 mg L(-1) of Fe(3+) in a pilot-scale compound parabolic collector plant was used to examine the disinfection and antibiotic resistance removal efficiency in different aqueous matrices, namely distilled water, simulated and real wastewater effluents. There was a faster complete removal of enterococci and of antibiotics in all aqueous matrices by applying solar Fenton when compared to photolytic treatment of the matrices. Sulfamethoxazole was more efficiently degraded than clarithromycin in all three aqueous matrices (95% removal of sulfamethoxazole and 70% removal of clarithromycin in real wastewater). The antibiotic resistance of enterococci towards both antibiotics exhibited a 5-log reduction with solar Fenton in real wastewater effluent. Also after solar Fenton treatment, there were 10 times more antibiotic-resistant enterococci in the presence of sulfamethoxazole than in the presence of clarithromycin. Finally, the toxicity

  1. Preparation and application of acidified/calcined red mud catalyst for catalytic degradation of butyl xanthate in Fenton-like process.

    Science.gov (United States)

    Shao, Luhua; Wei, Guangtao; Wang, Yizhi; Li, Zhongmin; Zhang, Linye; Zhao, Shukai; Zhou, Ming

    2016-08-01

    Acidified/calcined red mud (ACRM), a novel catalyst used in Fenton-like process, was prepared by acidification and calcination of red mud (RM). Catalyst characterization showed that iron phase of ACRM was mainly α-Fe2O3 and ACRM was a porous material with rough surface and loose structure. Degradation of butyl xanthate in Fenton-like process catalyzed by ACRM was investigated. Butyl xanthate was effectively degraded, and the degradation of butyl xanthate was well fitted by second order kinetic model. ACRM had an excellent long-term stability in a Fenton-like process. The possible mechanisms of hydroxyl radical production and butyl xanthate degradation in a Fenton-like process catalyzed by ACRM were presented.

  2. Relevance of Toxicity Assessment in Wastewater Treatments: Case Study—Four Fenton Processes Applied to the Mineralization of C.I. Acid Red 14

    Science.gov (United States)

    Idel-aouad, Rajaa; Valiente, Manuel; Gutiérrez-Bouzán, Carmen; Vilaseca, Mercè; Yaacoubi, Abdlrani; Tanouti, Boumediene; López-Mesas, Montserrat

    2015-01-01

    Fenton and Fenton-like processes, both in homogeneous and heterogeneous phases, have been applied to an aqueous solution containing the dye AR 14 in order to study the mineralization and toxicity of the solutions generated after color elimination. The mineralization of AR 14 occurred slower than the decolorization. The Microtox analysis of the treated solutions showed low toxicity intrinsic to the chemicals used in the process rather than the degradation products obtained after the treatment of the dye solution. The dye degradation for the Fenton oxidation process was initially faster than for the Fenton-like process but after a short time, the four processes showed similar degradation yields. All processes have shown good results being the heterogeneous process the most convenient since the pH adjustment is not necessary, the catalyst is recovered and reused and the generation of contaminated sludge is avoided. PMID:26167334

  3. Treatment of hazardous landfill leachate using Fenton process followed by a combined (UASB/DHS) system.

    Science.gov (United States)

    Ismail, Sherif; Tawfik, Ahmed

    2016-01-01

    Fenton process for pre-treatment of hazardous landfill leachate (HLL) was investigated. Total, particulate and soluble chemical oxygen demand (CODt, CODp and CODs) removal efficiency amounted to 67%, 47% and 64%, respectively, at pH value of 3.5, molar ratio (H2O2/Fe(2+)) of 5, H2O2 dosage of 25 ml/L and contact time of 15 min. Various treatment scenarios were attempted and focused on studying the effect of pre-catalytic oxidation process on the performance of up-flow anaerobic sludge blanket (UASB), UASB/down-flow hanging sponge (DHS) and DHS system. The results obtained indicated that pre-catalytic oxidation process improved the CODt removal efficiency in the UASB reactor by a value of 51.4%. Overall removal efficiencies of CODt, CODs and CODp were 80 ± 6%, 80 ± 7% and 78 ± 16% for UASB/DHS treating pre-catalytic oxidation effluent, respectively. The removal efficiencies of CODt, CODs and CODp were, respectively, decreased to 54 ± 2%, 49 ± 2% and 71 ± 16% for UASB/DHS system without pre-treatment. However, the results for the combined process (UASB/DHS) system is almost similar to those obtained for UASB reactor treating pre-catalytic oxidation effluent. The DHS system achieved average removal efficiencies of 52 ± 4% for CODt, 51 ± 4% for CODs and 52 ± 15% for CODp. A higher COD fractions removal was obtained when HLL was pre-treated by Fenton reagent. The combined processes provided a removal efficiency of 85 ± 1% for CODt, 85 ± 1% for CODs and 83 ± 8% for CODp. The DHS system is not only effective for organics degradation but also for ammonia oxidation. Almost complete ammonia (NH4-N) removal (92 ± 3.6%) was occurred and the nitrate production amounted to 37 ± 6 mg/L in the treated effluent. This study strongly recommends applying Fenton process followed by DHS system for treatment of HLL.

  4. TRATAMENTO DO LIXIVIADO DE ATERRO DE RESÍDUOS SÓLIDOS URBANOS POR PROCESSO FENTON

    Directory of Open Access Journals (Sweden)

    Victor Wegner Maus

    2009-09-01

    Full Text Available O lixiviado gerado em aterros sanitários pela decomposição dos resíduos sólidos com presença de água de infiltração possui grande potencial poluidor, devido à elevada concentração de substâncias tóxicas e a sua baixa biodegradabilidade. A coagulação química pode ser uma alternativa para o tratamento de efluentes com essas características. O trabalho teve como objetivo avaliar a eficiência do processo Fenton no tratamento de lixiviado gerado em aterros sanitários de resíduos sólidos urbanos. As amostras de lixiviado foram coletadas no aterro controlado do município de Santa Maria – RS. No experimento foram testados cinco tratamentos com diferentes proporções de reagentes (H2O2 e FeSO4 TH2O2/FeSO4: T0,8, T2,0, T3,0, T4,0 e T6,0. Pelos resultados do experimento com processo Fenton verifica-se uma eficiência média na remoção da demanda química de oxigênio (DQO de 47,9%, na turbidez de 53,0% e na cor de 70,7%. Os valores médios da demanda bioquímica de oxigênio (DBO e da condutividade elétrica aumentaram em 31,3% e 27,1%, respectivamente. No tratamento T0,8 constatou-se a maior remoção da DQO e o maior aumento da biodegradabilidade. O processo Fenton aplicado no tratamento de lixiviado reduz a DQO e aumenta a DBO, em outras palavras, aumenta a biodegradabilidade do efluente. Esse processo pode ser utilizado como pré-tratamento de um sistema biológico para efluentes de aterros sanitários.

  5. Isolation and identification of a novel aromatic amine mutagen produced by the Maillard reaction.

    Science.gov (United States)

    Nishigaki, Rena; Watanabe, Tetsushi; Kajimoto, Tetsuya; Tada, Atsuko; Takamura-Enya, Takeji; Enomoto, Shigeki; Nukaya, Haruo; Terao, Yoshiyasu; Muroyama, Atsushi; Ozeki, Minoru; Node, Manabu; Hasei, Tomohiro; Totsuka, Yukari; Wakabayashi, Keiji

    2009-09-01

    To clarify the formation of mutagens in the Maillard reaction of glucose and amino acids, 20 amino acids were separately incubated with glucose in the presence or absence of hydroxyl radicals produced by the Fenton reaction. After 1 week at 37 degrees C and pH 7.4, the reaction mixtures of glucose and tryptophan with and without the Fenton reagent showed mutagenicity toward Salmonella typhimurium YG1024 in the presence of a mammalian metabolic system (S9 mix). To identify mutagens in the reaction mixture, blue rayon-adsorbed material from a mixture of glucose, tryptophan, and the Fenton reagent was separated by column chromatography using various solid and mobile phases, and one mutagen, which accounted for 18% of the total mutagenicity of the reaction mixture, was isolated. The chemical structure of the mutagen was determined to be 5-amino-6-hydroxy-8H-benzo[6,7]azepino[5,4,3-de]quinolin-7-one (ABAQ) on the basis of ESI mass, high-resolution APCI mass, (1)H NMR, (13)C NMR, and IR spectral analyses and chemical synthesis of the mutagen. The novel aromatic amine showed high mutagenicity toward S. typhimurium TA98 and YG1024 with S9 mix, inducing 857 revertants of TA98 and 6007 revertants of YG1024/microg, respectively. The mutagenicity of ABAQ was comparable to that of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine, which is a mutagenic and carcinogenic hetrocyclic amine in cooked meat and fish formed through the Maillard reaction at high temperature.

  6. 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

    2015-05-22

    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 Fe(3+) can be achieved to regenerate Fe(2+). 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 Fe(2+) and Fe(3+). All these merits indicate that the composite catalyst possesses great potential for visible-light driven destruction of organic compounds.

  7. 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.

  8. Magnetically separable core-shell structural γ-Fe2O3@Cu/Al-MCM-41 nanocomposite and its performance in heterogeneous Fenton catalysis.

    Science.gov (United States)

    Ling, Yuhan; Long, Mingce; Hu, Peidong; Chen, Ya; Huang, Juwei

    2014-01-15

    To target the low catalytic activity and the inconvenient separation of copper loading nanocatalysts in heterogeneous Fenton-like reaction, a core-shell structural magnetically separable catalyst, with γ-Fe2O3 nanoparticles as the core layer and the copper and aluminum containing MCM-41 as the shell layer, has been fabricated. The role of aluminum has been discussed by comparing the copper containing mesoporous silica with various Cu contents. Their physiochemical properties have been characterized by XRD, UV-vis, FT-IR, TEM, nitrogen physisorption and magnetite susceptibility measurements. Double content Cu incorporation results in an improved catalytic activity for phenol degradation at the given condition (40°C, initial pH=4), but leads to a declined BET surface area and less ordered mesophase structure. Aluminum incorporation helps to retain the high BET surface area (785.2m(2)/g) and the regular hexagonal mesoporous structure of MCM-41, which make the catalyst possess a lower copper content and even a higher catalytic activity than that with the double copper content in the absence of aluminum. The catalysts can be facilely separated by an external magnetic field for recycle usage.

  9. Novel magnetic porous carbon spheres derived from chelating resin as a heterogeneous Fenton catalyst for the removal of methylene blue from aqueous solution.

    Science.gov (United States)

    Ma, Junjun; Zhou, Lincheng; Dan, Wenfeng; Zhang, He; Shao, Yanming; Bao, Chao; Jing, Lingyun

    2015-05-15

    Porous magnetic carbon spheres (MCS) were prepared from carbonized chelating resin composites derived from ethylenediaminetetraacetic acid-modified macroporous polystyrene (PS-EDTA) resin, and then loaded with iron composites via ion exchange. The resulting composites were characterized for this study using X-ray diffraction, MÖssbauer spectroscopy, and Raman spectroscopy, X-ray photoelectron spectroscopy, Brunauer-Emmett-Teller surface area method, scanning electron microscopy, and vibrating sample magnetometry. The porous magnetic carbon spheres were then used, in the existence of H2O2 and NH2OH, with a view to remove methylene blue from the aqueous solution by catalyze a heterogeneous Fenton reaction. Results indicated excellent removal rates and removal efficiency for this catalytic system. Optimal degradation was achieved (nearly 100% within 10 min) using initial concentrations of 5 mmol H2O2 L(-1), 2.5 mmol L(-1) NH2OH and 40 mg L(-1) methylene blue. The catalyst retained its activity after six reuses, indicating strong stability and reusability. Porosity of the catalyst contributed to its high activity, suggesting its potential application for the industrial treatment of wastewater.

  10. Fenton试剂氧化法预处理LDPE-g-MAH工艺废水%Wastewater treatment from production of LDPE-g-MAH by fenton reagent

    Institute of Scientific and Technical Information of China (English)

    李倩; 张宇峰; 李志涛

    2012-01-01

    Fenton reagent was used to degradate the wastewater from production of LDPE-g-MAH, and the optimal conditions were obtained as follows;the added mass tration of H2O2(30% ) was 10 mL with the adding ways of batch feed,the initial pH value of the solution was 4. 0,the molar ratio of H2O2 and Fe2+2 was 15, and reaction time was 40 min. Under optimal conditions, the removal rate of chemical oxygen consumption ( COD) reached 89. 03%.%采用Fenton氧化对聚乙烯(PE)悬浮接枝马来酸酐(MAH)工艺废水进行了降解试验研究,通过单因素试验确定了Fenton试剂降解废水的最佳操作条件.结果表明:分批投加质量分数为30%的H2O2,投加量10 mL,n(H2O2)/n( Fe2+)=15,反应初始pH为4.0,反应时间为40 min是Fenton反应体系的最佳操作条件,化学耗氧量(COD)的去除率可达到89.03%.

  11. Reactive Effect of Low Intensity He-Ne Laser upon Damaged Ultrastructure of Human Erythrocyte Membrane in Fenton System by Atomic Force Microscopy

    Institute of Scientific and Technical Information of China (English)

    Yanhong CUI; Zhouyi GUO; Yanping ZHAO; Ying ZHENG; Yanfang QIAO; Jiye CAI; Songhao LIU

    2007-01-01

    To find out the mechanism of modulating the deformability of erythrocytes with low intensity He-Ne laser action, we studied the effect of low intensity He-Ne laser on the ultrastructure of human erythrocyte membrane. Erythrocytes were treated with free radicals from a Fenton reaction system before exposing them to low intensity He-Ne laser. The ultrastructure of damaged erythrocyte membrane was examined by atomic force microscopy. The results showed that the erythrocyte membrane became very rough and the molecules on the surface of the membrane congregated into particles of different magnitudes sizes after treating with free radicals. Comparing the degree of congregation of the molecular particles in the non-irradiated group and the He-Ne laser irradiated (9 mW and 18 mW) group, we found the average size of molecular particles in the laser irradiated group was smaller than that in the non-irradiated group, indicating that the low intensity laser had repairing function to the damage of erythrocyte membrane produced by the free radicals.

  12. Effective heterogeneous electro-Fenton process for the degradation of a malodorous compound, indole using iron loaded alginate beads as a reusable catalyst

    OpenAIRE

    Hammouda, Samia Ben; Fourcade, Florence; Assadi, Aymen,; Soutrel, Isabelle; Adhoum, Nafâa; Amrane, Abdeltif; MONSER, LOTFI

    2016-01-01

    International audience; In this work the characterization and the performance of iron immobilized in alginate beads (Fe-ABs) as catalyst for heterogeneous electro-Fenton (EF) treatment of a malodorous compound, indole, was investigated. Experimental results demonstrated that indole was effectively removed through the electro-Fenton process; while in the considered experimental conditions, the performances of EF were only slightly improved by the addition of UVA radiation. The most efficient o...

  13. Photocatalytic degradation of the pesticide dimethoate by the nano TiO2-UV/Fenton or Fenton-like process%纳米TiO2-UV联合(类)Fenton试剂光催化降解乐果

    Institute of Scientific and Technical Information of China (English)

    王金翠; 王欣; 杜银花; 刘宝林

    2013-01-01

    The effects of H2O2,Fe2+ ,Fe2+ ,Cu2+ ,Fenton and Fenton-like reagents on the photodegrada-tion efficiency of dimethoate, an organophosphorous pesticide, in a nano TiO2 -UV system have been examined. The results indicated that the addition of H2O2 2 mmol/L or Cu2+1 mmol/L would be favorable for the degradation of dimethoate within the first 20 min, while the addition of Fe2+ or Fe2+ would hinder the process. Compared with Fenton-like reagents,the combination of nanometer TiO2-UV process with Fenton reagent would be more efficient for the degradation. When the Fenton reagent was composed of Fe2+ 1 mmol/L and H2O2 2 mmol/L and the initial pH value was 1 ,the dimethoate (20 mg/L) could be completely degraded by the nano TiO2-UV/ Fenton process within 20 min,and the degradation efficiency was relatively high.%以悬浮态纳米TiO2-UV光催化降解乐果体系为基础,首先研究了单纯添加H2O2、Fe2、Fe3+或Cu2+对降解过程影响,进而探讨添加Fenton或类Fenton试剂对降解过程的作用.结果表明,与单纯Fe2或Fe3+对乐果光催化降解过程的抑制作用相比,单独添加H2O22 mmol/L或Cu2+1 mmol/L有利于反应初期(0~20 min)内乐果纳米TiO2-UV光催化降解效果的提高;与类Fenton试剂相比,纳米TiO2-UV联合Fenton试剂能够有效促进乐果的降解;当在纳米TiO2-UV光催化降解乐果体系中添加由Fe2+1 mmol/L和H2O22 mmol/L组成的Fenton试剂,并调节反应液初始pH为1时,可使20 mg/L的乐果溶液在20 min内完全降解,具有相对较高的降解效率.

  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.

    Science.gov (United States)

    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 reduction of the solution initial pH from ca. 7.0 to ca. 3.5 had a positive effect on color removal. A complete color removal was achieved with all the H2O2 concentrations in the range of 0.007 - 0.067 M over the FeZSM-5 (42) catalyst after 2 h of reaction. The COD reduction increased from 52% to 81% with an increase in the amount of the catalyst. The COD reduction was affected positively with the increase in temperature from 298 K through 313 K to 323 K and then to 333 K. The initial decolorization rate was described by the equation: -rA0 = 9.4*10(4) e(-38.8/RT) CRR141,0 CH2O2,0 (0.184) with an H2O2 concentration range of 0.007 M - 0.033 M (where R is in kJ/mol).

  15. 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.

  16. Reaction routes leading to CO2 and CO in the Briggs-Rauscher oscillator: analogies between the oscillatory BR and BZ reactions.

    Science.gov (United States)

    Muntean, Norbert; Szabó, Gabriella; Wittmann, Maria; Lawson, Thuy; Fülöp, János; Noszticzius, Zoltán; Onel, Lavinia

    2009-08-13

    With Fenton-type experiments, it is shown that the intense CO2/CO evolution in the Briggs-Rauscher (BR) reaction is due to decarboxylation/decarbonylation of organic free radicals. The metal ion applied in the Fenton-type experiments was Fe2+ or Ti3+ or Mn2+ combined with H2O2 or S2O(8)(2-) as a peroxide, whereas the organic substrate was malonic acid (MA) or a 1:1 mixture of MA and iodomalonic acid (IMA). Experiments with a complete BR system applying MA or the MA/IMA mixture indicate that practically all CO2 and CO comes from IMA. The decarboxylation/decarbonylation mechanisms of various iodomalonyl radicals can be analogous to that of the bromomalonyl radicals studied already in the Belousov-Zhabotinsky (BZ) reaction. It is found that an intense CO2/CO evolution requires the simultaneous presence of H2O2, IO3-, Mn2+, and IMA. It is suggested that the critical first step of this complex reaction takes place in the coordination sphere of Mn2+. That first step can initiate a chain reaction where organic and hydroperoxyl radicals are the chain carriers. A chain reaction was already found in a BZ oscillator as well. Therefore, the analogies between the BR and BZ oscillators are due to the fact that in both mechanisms, free radicals and, in most cases, also transition-metal complexes play an important role.

  17. Hot Dry Rock Project modification and expansion, Fenton Hill, Sandoval County, New Mexico: Environmental assessment

    Energy Technology Data Exchange (ETDEWEB)

    1979-09-01

    This environmental assessment (EA) addresses the modification and expansion of the ongoing Hot Dry Rock Project at Fenton Hill, New Mexico. Modifications to the Project include the upgrading and improvement of the hot dry rock (HDR) heat transfer system and the onsite support facilities. At least one new heat extraction well will be drilled to accommodate a large thermal loop experiment. The existing wells will be redrilled to greater depth. Expansion of the Project includes the construction and operation of heat utilization facilities (that is, 60 kW electric generator and greenhouse), wellbore equipment test station, large-capacity water supply and storage system, water treatment facility, and additional seismic monitoring stations. This EA addresses the potential environmental impacts of the total facility as expanded to accommodate the large thermal loop and heat utilization experiments.

  18. 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.

  19. Remediation of hydrocarbons in crude oil-contaminated soils using Fenton's reagent.

    Science.gov (United States)

    Ojinnaka, Chukwunonye; Osuji, Leo; Achugasim, Ozioma

    2012-11-01

    Sandy soil samples spiked with Bonny light crude oil were subsequently treated with Fenton's reagent at acidic, neutral, and basic pH ranges. Oil extracts from these samples including an untreated one were analyzed 1 week later with a gas chromatograph to provide evidence of hydrocarbon depletion by the oxidant. The reduction of three broad hydrocarbon groups-total petroleum hydrocarbon (TPH); benzene, toluene, ethylbenzene, and xylene (BTEX); and polycyclic aromatic hydrocarbon (PAH) were investigated at various pHs. Hydrocarbon removal was efficient, with treatment at the acidic pH giving the highest removal of about 96% for PAH, 99% for BTEX, and some TPH components experiencing complete disappearance. The four-ringed PAHs were depleted more than their three-ringed counterparts at the studied pH ranges.

  20. Geological structures from televiewer logs of GT-2, Fenton Hill, New Mexico: Part 2, Rectification

    Energy Technology Data Exchange (ETDEWEB)

    Burns, K.L.

    1987-08-01

    Televiewer logs from drill hole GT-2 at the Fenton Hill, New Mexico, Hot Dry Rock Site, have been rectified by conversion of structural traces on the scanner imagery to geographic location and orientation. The rectification method was direct inversion that consisted of mapping from the image to the wellbore, inverting the trace on the wellbore for principal points, and rotating from wellbore to geographic coordinates. From the test imagery of GT-2, 733 structures (fractures and foliations) were measured, compared with 42 structures from recovered core. The 733 new measurements listed in this report are a unique and unrepeatable collection of structural information from the Precambrian basement of northern New Mexico. This direct inversion method is accurate where the magnetic field vector is constant and the tool is centered and aligned in a circular wellbore. In other cases this method yields only approximate results.

  1. Fenton-like degradation of Bisphenol A catalyzed by mesoporous Cu/TUD-1

    Science.gov (United States)

    Pachamuthu, Muthusamy P.; Karthikeyan, Sekar; Maheswari, Rajamanickam; Lee, Adam F.; Ramanathan, Anand

    2017-01-01

    A family of copper oxide catalysts with loadings spanning 1-5 wt% were dispersed on a three dimensional, mesoporous TUD-1 silica through a hydrothermal, surfactant-free route employing tetraethylene glycol as a structure-directing agent. Their bulk and surface properties were characterized by N2 physisorption, XRD, DRUVS, EPR, TEM and Raman spectroscopy, confirming the expected mesoporous wormhole/foam support morphology and presence of well-dispersed CuO nanoparticles (∼5-20 nm). The catalytic performance of Cu/TUD-1 was evaluated as heterogeneous Fenton-like catalysts for Bisphenol A (BPA) oxidative degradation in the presence of H2O2 as a function of [H2O2], and CuO loading. Up to 90.4% of 100 ppm BPA removal was achieved over 2.5 wt% Cu/TUD-1 within 180 min, with negligible Cu leaching into the treated water.

  2. Elimination of drugs of abuse and their toxicity from natural waters by photo-Fenton treatment.

    Science.gov (United States)

    Catalá, M; Domínguez-Morueco, N; Migens, A; Molina, R; Martínez, F; Valcárcel, Y; Mastroianni, N; López de Alda, M; Barceló, D; Segura, Y

    2015-07-01

    This paper investigates the elimination of drugs of abuse from six different chemical classes and their metabolites in natural fluvial waters (nearby the output of a sewage system). Mineralization of these substances and toxicological characterization before and after treatment by a heterogeneous photo-Fenton system has been evaluated. This advanced oxidation technology was able to significantly reduce the concentration of the drugs of abuse in all the tested conditions (different hydrogen peroxide and catalyst loadings). However, toxicological analyses measured as inhibition of fern spore mitochondrial activity, showed only a complete elimination of acute and chronic toxicity when a higher solid catalyst loading was used (0.6 g/L). A lower catalyst loading of 0.2 g/L was not enough for toxicity elimination. These results evidence the need for combining toxicological tests and chemical analyses in order to establish the effectiveness of the water treatment technologies based on advanced oxidation processes.

  3. INFLUENCIA DEL pH EN PROCESOS FOTO-FENTON UTILIZANDO Fe-PILCs COMO CATALIZADOR

    OpenAIRE

    Carolina Noya; Andrea De León; Marta Sergio; Juan Bussi

    2011-01-01

    En este trabajo se reporta la actividad catalítica de una arcilla pilareada con hierro (Fe-PILC) en la degradación de naranja de metilo mediante la técnica foto-Fenton heterogénea. Se prepararon Fe-PILCs a partir de una arcilla natural empleando diferentes temperaturas de calcinación: 350°C y 500°C. Los sólidos obtenidos se caracterizaron por análisis termogravimétrico y adsorción de nitrógeno, no observándose diferencias significativas de sus parámetros texturales (área específica y volumen ...

  4. Fighting Fenton Chemistry: A Highly Active Iron(III) Tetracarbene Complex in Epoxidation Catalysis.

    Science.gov (United States)

    Kück, Jens W; Anneser, Markus R; Hofmann, Benjamin; Pöthig, Alexander; Cokoja, Mirza; Kühn, Fritz E

    2015-12-07

    Organometallic Fe complexes with exceptionally high activities in homogeneous epoxidation catalysis are reported. The compounds display Fe(II) and Fe(III) oxidation states and bear a tetracarbene ligand. The more active catalyst exhibits activities up to 183 000 turnovers per hour at room temperature and turnover numbers of up to 4300 at -30 °C. For the Fe(III) complex, a decreased Fenton-type reactivity is observed compared with Fe(II) catalysts reported previously as indicated by a substantially lower H2 O2 decomposition and higher (initial) turnover frequencies. The dependence of the catalyst performance on the catalyst loading, substrate, water addition, and the oxidant is investigated. Under all applied conditions, the advantageous nature of the use of the Fe(III) complex is evident.

  5. Solar photo-Fenton treatment of chip board production waste water

    Energy Technology Data Exchange (ETDEWEB)

    Machado, A.E. da H.; Xavier, T.P.; Souza, D.R. de; Miranda, J.A. de; Duarte, E.T.F.M.; Ruggiero, R. [Universidade Federal de Uberlandia, Minas Gerais (Brazil). Lab. de Fotoquimica; Oliveira, L. de; Sattler, C. [Deutsches Zentrum fuer Luft- und Raumfahrt e.V., Koeln Porz (Germany)

    2004-11-01

    In a joint project the Universidade Federal de Uberlandia and the German Aerospace Center are developing solar water treatment technologies for industrial applications. Wastewater from chip-board production is difficult to detoxify by standard processes. Different advanced oxidation processes using solar light were tested on this effluent. In opposition to TiO{sub 2} treatment, the application of the photo-Fenton process using a compound parabolic collector (CPC) type solar reactor shows excellent results, with a reduction in the COD higher than 70% with the application of about 800 kJ m{sup -2} of UVA radiation. HPLC analysis shows an efficient degradation of the organic matter present in the effluent (formaldehyde, melamine, urea, wood extractives, lignin and urea/formaldehyde and melamine/formaldehyde resins fragments) prior to their complete disappearance. (Author)

  6. [Study on treatment of methylene blue wastewater by fly ash adsorption-Fenton and thermal regeneration].

    Science.gov (United States)

    Bai, Yu-Jie; Zhang, Ai-Li; Zhou, Ji-Ti

    2012-07-01

    The physicochemical properties of water-washed fly ash (FA) and acid modified fly ash (M-FA) were investigated. The adsorption of methylene blue by FA and M-FA were studied by batch experiments. Two methods, Fenton-drive oxidation regeneration and thermal regeneration, were used for regeneration of the used FA and M-FA. The result showed that the rate of adsorption process followed the second order kinetics and the adsorption followed Langmuir isotherms. The adsorption equilibrium time was 30 min, and the equilibrium adsorption capacity of FA and M-FA were 4.22 mg x g(-1) and 5.98 mg x g(-1) respectively. The adsorption capability of M-FA was higher than that of FA. In the range of pH 2-12, the adsorption capacity of M-FA increased with the increase of pH, whereas the adsorption capacity of FA decreased slowly until the pH 8 and then increased. Electrostatic adsorption was the major factor on the adsorption capacity. Around 61% and 55% percentage regeneration (PR) were obtained for FA and M-FA respectively when 78.4 mmol x L(-1) H2O2 and 0.72 mmol x L(-1) Fe2+ were used. When the condition of thermal regeneration was 400 degrees C and 2 h, a positive correlation can be found between the PRs of FA and regeneration times, the PRs were 102%, 104% and 107% in three cycles of adsorption-thermal regeneration process. However a negative correlation can be found between the PRs of M-FA and regeneration times, the PRs were 82%, 75% and 74% in three cycles of adsorption-thermal regeneration process. The PR of FA was higher than that of M-FA, and thermal regeneration was superior to Fenton-drive regeneration.

  7. Chloroethene dechlorination in acidic groundwater: Implications for combining fenton's treatment with natural attenuation

    Science.gov (United States)

    Bradley, Paul M.; Singletary , Michael A.; Chapelle, Francis H.

    2007-01-01

    A sulfuric acid leak in 1988 at a chloroethene-contaminated groundwater site at the Naval Air Station Pensacola has resulted in a long-term record of the behavior of chloroethene contaminants at low pH and a unique opportunity to assess the potential impact of source area treatment technologies, which involve acidification of the groundwater environment (e.g., Fenton's-based in situ chemical oxidation), on downgradient natural attenuation processes. The greater than 75 percent decrease in trichloroethene (TCE) concentrations and the shift in contaminant composition toward predominantly reduced daughter products (dichloroethene [DCE] and vinyl chloride [VC]) that were observed along a 30-m groundwater flow path characterized by highly acidic conditions (pH = 3.5 ± 0.4) demonstrated that chloroethene reductive dechlorination can continue to be efficient under persistent acidic conditions. The detection of Dehalococcoides-type bacteria within the sulfuric acid/chloroethene co-contaminant plume was consistent with biotic chloroethene reductive dechlorination. Microcosm studies conducted with 14C-TCE and 14C-VC confirmed biotic reductive dechlorination in sediment collected from within the sulfuric acid/chloroethene co-contaminant plume. Microcosms prepared with sediment from two other locations within the acid plume, however, demonstrated only a limited mineralization to 14CO2 and 14CO, which was attributed to abiotic degradation because no significant differences were observed between experimental and autoclaved control treatments. These results indicated that biotic and abiotic mechanisms contributed to chloroethene attenuation in the acid plume at NAS Pensacola and that remediation techniques involving acidification of the groundwater environment (e.g., Fenton's-based source area treatment) do not necessarily preclude efficient chloroethene degradation.

  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. 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.

  10. Nanoscale zero-valent iron/AC as heterogeneous Fenton catalysts in three-dimensional electrode system.

    Science.gov (United States)

    Zhang, Chao; Zhou, Lei; Yang, Jie; Yu, Xinmin; Jiang, Yonghai; Zhou, Minghua

    2014-01-01

    In the present work, nanoscale zero-valent iron/activated carbon (NZVI/AC) was investigated as heterogeneous Fenton catalyst in three-dimensional (3D) electrode system for methyl orange (MO) degradation. Some important operating parameters such as cathodic potential, pH, and O₂ flow rate were investigated, exhibiting good decolorization. The mineralization of MO was significantly improved by 20-35% compared to two-dimensional (2D) AC system at the optimum conditions. Although the TOC removal of AC was higher than NZVI/AC due to its good adsorption capacity initially, heterogeneous Fenton catalysis played a more and more important roles in the following test. After eight runs, NZVI/AC still exhibited excellent catalytic properties with low iron leaching. Further, a relatively comprehensive mechanism of NZVI/AC as particle electrodes in 3D system was proposed.

  11. Treatment and reuse of textile wastewaters by mild solar photo-Fenton in the presence of humic-like substances.

    Science.gov (United States)

    Negueroles, P G; Bou-Belda, E; Santos-Juanes, L; Amat, A M; Arques, A; Vercher, R F; Monllor, P; Vicente, R

    2016-10-25

    In this paper, the possibility of reusing textile effluents for new dyeing baths has been investigated. For this purpose, different trichromies using Direct Red 80, Direct Blue 106, and Direct Yellow 98 on cotton have been used. Effluents have been treated by means of a photo-Fenton process at pH 5. Addition of humic-like substances isolated form urban wastes is necessary in order to prevent iron deactivation because of the formation of non-active iron hydroxides. Laboratory-scale experiments carried out with synthetic effluents show that comparable results were obtained when using as solvent water treated by photo-Fenton with SBO and fresh deionized water. Experiments were scaled up to pilot plant illuminated under sunlight, using in this case a real textile effluent. Decoloration of the effluent could be achieved after moderate irradiation and cotton dyed with this water presented similar characteristics as when deionized water was used.

  12. Electrochemical Reduction Prior to Electro-Fenton Oxidation of Azo Dyes : Impact of the Pretreatment on Biodegradability.

    OpenAIRE

    Fourcade, Florence; Delawarde, Mathieu; Guihard, Laurence; Nicolas, Stéphane; Amrane, Abdelatif

    2013-01-01

    International audience; The aim of this work was to study the degradation of three azo dyes, Orange II, Methyl red and Biebrich Scarlet by electro-Fenton and the effect of the electrochemical pretreatment on the biodegradability of the solutions. The electrochemical pretreatment showed that an electrochemical reduction on the carbon felt electrode was mainly responsible for the decolorization of the azo dyes. Indeed, the electrochemical behaviour of the azo dyes highlighted their electroactiv...

  13. 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...

  14. 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.

  15. Synthesis, characterization and performance of high energy ball milled meso-scale zero valent iron in Fenton reaction.

    Science.gov (United States)

    Ambika, Selvaraj; Devasena, M; Nambi, Indumathi Manivannan

    2016-10-01

    Understanding contaminant degradation by different sized zero valent iron (ZVI) particles is one important aspect in addressing the long-term stability of these particles in field studies. In this study, meso zero valent iron (mZVI) particles were synthesised in a milling time of 10 h using ball milling technique. The efficacy of mZVI particles for removal of phenol was quantitatively evaluated in comparison with coarse zero valent iron (cZVI) and nano zero valent iron (nZVI) particles. Phenol degradation experiments were carried out in sacrificial batch mode at room temperature independently with cZVI, nZVI and mZVI under varied pH conditions of 3, 4, 6, 7, 8 and 10. Batch experiments substantiating the reactivity of mZVI under unbuffered pH system were also carried out and compared with buffered and poorly buffered pH systems. mZVI particles showed consistent phenol degradation at circum-neutral pH with efficiency of 44%, 67%, and 89% in a span of 5, 10 and 20 min respectively. The dissolved iron species and residual iron formation were also measured as a function of pH. Unbuffered systems at circum-neutral pH produced less residual iron when compared to buffered and poorly buffered systems. At this pH, oxidation of Fe(2+) produced a different oxidant Ferryl ion, which was found to effectively participate in phenol degradation.

  16. Isolation and structural identification of a direct-acting mutagen derived from N-nitroso-N-methylpentylamine and Fenton's reagent with copper ion.

    Science.gov (United States)

    Miura, Motofumi; Inami, Keiko; Yoshida, Masafumi; Yamaguchi, Kentaro; Mashino, Tadahiko; Mochizuki, Masataka

    2011-09-15

    N-Nitrosodialkylamines show their mutagenicity by forming α-hydroxynitrosamines in the presence of rat S9 mix in the Ames assay. The hydroxyl radical derived from Fe(2+)-H(2)O(2) (Fenton's reagent) with Cu(2+) activates N-nitrosamines, with an alkyl chain longer than a propyl constituent, to a direct-acting mutagen. The reactivity of Fe(2+)-Cu(2+)-H(2)O(2) on nitrosamines in relation to their metabolic activation is not fully characterized. Here, we report the identification of the direct-acting mutagen derived from N-nitroso-N-methylpentylamine (NMPe) in the presence of Fe(2+), Cu(2+), H(2)O(2) and nitric oxide (NO), which is a product of nitrosamine metabolism. A dichloromethane extract of the NMPe reaction mixtures was fractionated by silica gel column chromatography several times and by a preparative high performance liquid chromatography (HPLC); we obtained white crystals as a product. The direct-acting mutagen that was isolated was provisionally identified as 5-ethyl-5-nitro-1-pyrazoline 1-oxide by (1)H and (13)C nuclear magnetic resonance (NMR) spectroscopy, infrared (IR) spectroscopy and X-ray crystallography. To confirm the structure of the mutagen, the authentic compound was synthesized from 2-nitrobutene and diazomethane, followed by N-oxidation with m-chloroperoxybenzoic acid. The (1)H NMR spectral data from the direct-acting mutagen that was synthesized was identical to the data from the isolated mutagen. Furthermore, the authentic 5-ethyl-5-nitro-1-pyrazoline 1-oxide was mutagenic in Salmonella typhimurium TA1535. The results showed that 5-ethyl-5-nitro-1-pyrazoline 1-oxide was a direct-acting mutagen derived from the reaction of NMPe and Fe(2+)-Cu(2+)-H(2)O(2)-NO.

  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).

  18. Treatment of crystallized-fruit wastewater by UV-A LED photo-Fenton and coagulation-flocculation.

    Science.gov (United States)

    Rodríguez-Chueca, Jorge; Amor, Carlos; Fernandes, José R; Tavares, Pedro B; Lucas, Marco S; Peres, José A

    2016-02-01

    This work reports the treatment of crystallized-fruit effluents, characterized by a very low biodegradability (BOD5/COD UV-A LED photo-Fenton process. Firstly, a Box-Behnken design of Response Surface Methodology was applied to achieve the optimal conditions for the UV-A LED photo-Fenton process, trying to maximize the efficiency by saving chemicals and time. Under the optimal conditions ([H2O2] = 5459 mg/L; [Fe(3+)] = 286 mg/L; time >180 min), a COD removal of 45, 64 and 74% was achieved after 360 min, using an irradiance of 23, 70 and 85 W/m(2) respectively. Then a combination of UV-A LED photo-Fenton with coagulation-flocculation-decantation attained a higher COD removal (80%), as well as almost total removal of turbidity (99%) and total suspended solids (95%). Subsequent biodegradability of treated effluents increased, allowing the application of a biological treatment step after the photochemical/CFD with 85 W/m(2).

  19. Optimisation of decolourisation and degradation of Reactive Black 5 dye under electro-Fenton process using Fe alginate gel beads.

    Science.gov (United States)

    Iglesias, O; Fernández de Dios, M A; Rosales, E; Pazos, M; Sanromán, M A

    2013-04-01

    The aim of this work was to improve the ability of the electro-Fenton process using Fe alginate gel beads for the remediation of wastewater contaminated with synthetic dyes and using a model diazo dye such as Reactive Black 5 (RB5). Batch experiments were conducted to study the effects of main parameters, such as voltage, pH and iron concentration. Dye decolourisation, reduction of chemical oxygen demand (COD) and energy consumption were studied. Central composite face-centred experimental design matrix and response surface methodology were applied to design the experiments and to evaluate the interactive effects of the three studied parameters. A total of 20 experimental runs were set, and the kinetic data were analysed using first-order and second-order models. In all cases, the experimental data were fitted to the empirical second-order model with a suitable degree for the maximum decolourisation of RB5, COD reduction and energy consumption by electro-Fenton-Fe alginate gel beads treatment. Working with the obtained empirical model, the optimisation of the process was carried out. The second-order polynomial regression model suggests that the optimum conditions for attaining maximum decolourisation, COD reduction and energy consumption are voltage, 5.69 V; pH 2.24 and iron concentration, 2.68 mM. Moreover, the fixation of iron on alginate beads suggests that the degradation process can be developed under this electro-Fenton process in repeated batches and in a continuous mode.

  20. Performance evaluation of a photo-Fenton process applied to pollutant removal from textile effluents in a batch system.

    Science.gov (United States)

    Módenes, A N; Espinoza-Quiñones, F R; Manenti, D R; Borba, F H; Palácio, S M; Colombo, A

    2012-08-15

    In this work, the performance of a photo-Fenton process-based textile effluent treatment was investigated using both solar and artificial light sources. A full 3(3) factorial experimental design was applied for the optimisation with respect to three parameters: initial pH, amounts of Fe(2+) (0.01-0.09 g L(-1)) and H(2)O(2) (1-7 g L(-1)). The photo-Fenton process response was evaluated on the basis of chemical oxygen demand (COD) removal and decolourisation. The optimum conditions of the photo-Fenton process were attained at concentration values of 0.05 g Fe(2+) L(-1) and 6.0 g H(2)O(2) L(-1) and pH 3, for both solar and artificial light sources. The effects of initial pH, and Fe(2+) and H(2)O(2) concentrations were evaluated. From the monitoring of TOC, COD, turbidity and decolourisation over time, the progress of the mineralisation of dyes was analysed, forming nitrate, ammonia nitrogen and nitrite. Low amounts of residual peroxide and iron, which were below the limit allowed by Brazilian environmental legislation, were attained after 360 min of irradiation time for both artificial and solar sources. An operational cost of US$ 6.85 per m(3) of treated effluent was estimated using solar irradiation.

  1. Effect of ultrasonication and Fenton oxidation on biodegradation of bis(2-ethylhexyl) phthalate (DEHP) in wastewater sludge.

    Science.gov (United States)

    Pham, T T H; Tyagi, R D; Brar, S K; Surampalli, R Y

    2011-02-01

    The presence of bis(2-ethylhexyl) phthalate (DEHP) and its metabolites, i.e. 2-ethylhexanol, 2-ethylhexanal, and 2-ethylhexanoic acid in wastewater sludge (WWS) were investigated during aerobic digestion and Bacillus thuringiensis (Bt)-based fermentation of WWS. Ultrasonication and Fenton oxidation pre-treatment was applied to improve biodegradability of WWS and bioavailability of the target compounds for digestion and fermentation. DEHP and 2-ethylhexanoic acid were observed at higher concentration, meanwhile 2-ethylhexanol and 2-ethylhexanal were observed at lower concentration in WWS. After 20-day aerobic digestion, DEHP removal was 72%, 89%, and 85%, and 2-ethylhexanoic acid removal was 71%, 84%, 79%, respectively for raw, ultrasonicated, and Fenton-oxidized sludges. Bt was found to degrade DEHP, leading to DEHP removal of 21%, 40%, and 30%, respectively for raw, ultrasonicated, and Fenton-oxidized sludges in the fermentation. The results suggested that aerobic stabilization and Bt-based fermentation can remove the phthalates, and pre-treatment of WWS was also effective in improvement of DEHP biodegradation. Hence, Bt-based biopesticide production from WWS can be applied safely when taking into consideration the phthalate contaminants.

  2. Enhancement of enzymatic saccharification of corn stover with sequential Fenton pretreatment and dilute NaOH extraction.

    Science.gov (United States)

    He, Yu-Cai; Ding, Yun; Xue, Yu-Feng; Yang, Bin; Liu, Feng; Wang, Cheng; Zhu, Zheng-Zhong; Qing, Qing; Wu, Hao; Zhu, Cheng; Tao, Zhi-Cheng; Zhang, Dan-Ping

    2015-10-01

    In this study, an effective method by the sequential Fenton pretreatment and dilute NaOH extraction (FT-AE) was chosen for pretreating corn stover. Before dilute NaOH (0.75 wt%) extraction at 90 °C for 1h, Fenton reagent (0.95 g/L of FeSO4 and 29.8 g/L of H2O2) was employed to pretreat CS at a solid/liquid ratio of 1/20 (w/w) at 35 °C for 30 min. The changes in the cellulose structural characteristics (porosity, morphology, and crystallinity) of the pretreated solid residue were correlated with the enhancement of enzymatic saccharification. After being enzymatically hydrolyzed for 72 h, the reducing sugars and glucose from the hydrolysis of 60 g/L FT-AE-CS pretreated could be obtained at 40.96 and 23.61 g/L, respectively. Finally, the recovered hydrolyzates containing glucose had no inhibitory effects on the ethanol fermenting microorganism. In conclusion, the sequential Fenton pretreatment and dilute NaOH extraction has high potential application in future.

  3. Degradation of acid red 97 dye in aqueous medium using wet oxidation and electro-Fenton techniques.

    Science.gov (United States)

    Kayan, Berkant; Gözmen, Belgin; Demirel, Muhammet; Gizir, A Murat

    2010-05-15

    Degradation of the acid red 97 dye using wet oxidation, by different oxidants, and electro-Fenton systems was investigated in this study. The oxidation effect of different oxidants such as molecular oxygen, periodate, persulfate, bromate, and hydrogen peroxide in wet oxidation system was compared. Mineralization of AR97 with periodate appeared more effective when compared with that of the other oxidants at equal initial concentration. When 5 mM of periodate was used, at the first minute of the oxidative treatment, the decolorization percentage of AR97 solution at 150 and 200 degrees C reached 88 and 98%, respectively. The total organic carbon removal efficiency at these temperatures also reached 60 and 80%. The degradation of AR97 was also studied by electro-Fenton process. The optimal current value and Fe(2+) concentration were found to be 300 mA and 0.2 mM, respectively. The results showed that electro-Fenton process can lead to 70 and 95% mineralization of the dye solution after 3 and 5h giving carboxylic acids and inorganic ions as final end-products before mineralization. The products obtained from degradation were identified by GC/MS as 1,2-naphthalenediol, 1,1'-biphenyl-4-amino-4-ol, 2-naphthalenol diazonium, 2-naphthalenol, 2,3-dihydroxy-1,4-naphthalenedion, phthalic anhydride, 1,2-benzenedicarboxylic acid, phthaldehyde, 3-hydroxy-1,2-benzenedicarboxylic acid, 4-amino-benzoic acid, and 2-formyl-benzoic acid.

  4. Oxalate enhanced mechanism of hydroxyl-Fe-pillared bentonite during the degradation of Orange II by UV-Fenton process.

    Science.gov (United States)

    Chen, Jianxin; Zhu, Lizhong

    2011-01-30

    An enhanced method of hydroxyl-Fe-pillared bentonite (H-Fe-P-B) during the degradation of Orange II was studied to provide novel insight to interactions of degradation intermediates with heterogeneous catalyst in UV-Fenton system. Based on the degradation mechanism of Orange II, oxalate enhanced mechanism of H-Fe-P-B in heterogeneous UV-Fenton system was developed. The results showed that additional oxalate could increase the Fe leaching of H-Fe-P-B during heterogeneous UV-Fenton process, which led to higher mineralization efficiency of Orange II and lower energy consumption of treatment. When the concentrations of additional sodium oxalate increased up to 0.1 mmol L(-1), 0.2 mmol L(-1) and 0.4 mmol L(-1), the rate of Orange II degradation could increase 30%, 46% and 63%, respectively. The iron ions leached from catalyst could be adsorbed back to the catalyst again after the organic intermediates were mineralized completely. Then the catalyst of H-Fe-P-B could be reused and additional pollution caused by iron ions could be avoided.

  5. 焦化废水泡沫分离液的Fenton催化氧化预处理%Pretreatment of the foaming wastewater from coking wastewater station by Fenton oxidation

    Institute of Scientific and Technical Information of China (English)

    何勤聪; 韦朝海; 陈学勇; 潘霞霞; 吴超飞; 卢彬

    2009-01-01

    以焦化废水处理过程产生的泡沫分离液为研究对象,对其进行Fenton催化氧化处理实验,考察H_2O_2用蜃、Fe~(2+)"浓度、pH和反应时间4个因素对处理效果的影响,并结合GC/MS方法比较处理前后泡沫分离液中有机物的种类及其生物降解性的变化.结果表明,采用[H_2O_2]=100 mmol/L、[Fe~(2+)]=100 mg/L、pH=3、反应时间为30 min的Fenton催化氧化反应条件,可以使分离液的COD去除率达到68%以上;经Fenton处理后,分离液的B/C值由0.12提高至0.38,生物降解性明显改善;通过GC/MS的分析,基本明确分离液中含有的有机物主要为酚、胺、腈、酯类有机物及喹啉、吡啶等杂环化合物,大多数属于难降解且生物毒性较强的有机物.针对这些复杂组分共存的泡沫分离液,利用Fenton试剂较强的氧化能力能够将其含有的有毒/难降解有机物转化为低毒或无毒的小分子有机物,为其后续的生物处理创造良好的条件.%The foaming wastewater from coking wastewater station was studied. It was treated by Fenton ox-idation technology. The effects of H_2O_2 dosage,Fe~(2+) concentration,pH and reaction time on the process were reviewed. The biodegradability was compared through hiodegradation experiment and organic compounds in the foaming wastewater analyzed by GC/MS method. The results indicated that COD removal rate of the foaming wastewater could reach 68% when [H_2O_2] = 100 mmoL/L,[Fe~(2+)]= 100 mg/L,pH =3 and the reaction time 30 min. The B/C value was increased from 0. 12 to 0. 38 after Fenton oxidation. The foaming wastewater con-tained kinds of organic pollutants,such as phenols,anilines,nitriles,esters,quinoline,pyridine and so on.Most of the pollutants belonged to non-biodegradable compounds and presented high toxicity. Fenton reagent had strong ability for oxidizing the hard-biodegradable compounds and could turn them into low-toxic or nontoxic products with small molecular structure. Therefore,Fenton

  6. 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

  7. Advanced treatment of cellulose ethanol wastewater by Fenton oxidation%Fenton氧化法深度处理纤维素乙醇废水

    Institute of Scientific and Technical Information of China (English)

    胡豫娟; 胡奇; 高大文

    2016-01-01

    采用Fenton氧化法深度处理经生化降解后的纤维素乙醇废水,考察了初始pH值、Fe2+与H2O2的投加比例(物质的量之比)、H2O2投加量与COD的比例(质量之比)以及反应时间对COD和浊度去除的影响,并通过正交实验确定了反应的最佳条件.研究表明:初始pH值、Fe2+/H2O2、H2O2/COD以及反应时间对深度处理效果有不同程度的影响;在初始pH值为3.0、Fe2+/H2O2为2∶3、H2O2/COD为2.8、反应时间为3h的最佳反应条件下,出水COD为45~56 mg·L-1,浊度为2~3 NTU,达到了纤维素乙醇废水的排放标准.%Fenton oxidation was employed in the advanced treatment of cellulose ethanol wastewater after biochemical degradation.The influence of initial pH,ratio of Fe2+/H2O2 (molar ratio),ratio of H2O2/COD (mass ratio),and reaction time on the COD and turbidity removal efficiencies were investigated.These parameters were selected as the variables in the orthogonal experiment performed to determine the optimum reaction conditions.The research showed that initial pH,Fe2+/H2O2,H2O2/COD,and reaction time influenced the COD and turbidity removal efficiencies to different degrees.Under the optimum reaction conditions (initial pH of 3.0,Fe2+/H2O2 of 2 ∶ 3,H2O2/COD of 2.8,and reaction time of 3 h),the effluent COD was 45 to 56 mg · L-1,and the effluent turbidity was 2 to 3 NTU,both of which measured up to the state standards of cellulose ethanol wastewater.

  8. Electro-Fenton treatment of mature landfill leachate in a continuous flow reactor

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hui, E-mail: eeng@whu.edu.cn [Department of Environmental Engineering, Hubei Biomass-Resource Chemistry and Environmental Biotechnology Key Laboratory, Wuhan University, P.O. Box C319, Luoyu Road 129, Wuhan 430079 (China); Ran, Xiaoni; Wu, Xiaogang [Department of Environmental Engineering, Hubei Biomass-Resource Chemistry and Environmental Biotechnology Key Laboratory, Wuhan University, P.O. Box C319, Luoyu Road 129, Wuhan 430079 (China)

    2012-11-30

    Highlights: Black-Right-Pointing-Pointer CSTR mode was used for COD removal of landfill leachate by Fered-Fenton process. Black-Right-Pointing-Pointer The complete mixing condition in the CSTR was verified. Black-Right-Pointing-Pointer A modified pseudo-first order kinetic model was developed. Black-Right-Pointing-Pointer The effects of important parameters on COD removal were investigated. Black-Right-Pointing-Pointer The organic components before and after treatment were determined by GC-MS. - Abstract: The treatment of mature landfill leachate by EF-Fere (also called Fered-Fenton) method was carried out in a continuous stirred tank reactor (CSTR) using Ti/RuO{sub 2}-IrO{sub 2}-SnO{sub 2}-TiO{sub 2} mesh anodes and Ti mesh cathodes. The effects of important parameters, including initial pH, inter-electrode gap, H{sub 2}O{sub 2} to Fe{sup 2+} molar ratio, H{sub 2}O{sub 2} dosage and hydraulic retention time, on COD removal were investigated. The results showed that the complete mixing condition was fulfilled in the electrochemical reactor employed in this study and COD removal followed a modified pseudo-first order kinetic model. The COD removal efficiency increased with the decrease of H{sub 2}O{sub 2} to Fe{sup 2+} molar ratio and hydraulic retention time. There existed an optimal inter-electrode gap or H{sub 2}O{sub 2} dosage so that the highest COD removal was achieved. Nearly the same COD removal was obtained at initial pH 3 and 5, but the steady state was quickly achieved at initial pH 3. The organic pollutants in the leachate were analyzed through a gas chromatography coupled with mass spectrometry (GC-MS) system. About 73 organics were detected in the leachate, and 52 of which were completely removed after EF-Fere process.

  9. Bioremediation of diesel-polluted soil using biostimulation as post-treatment after oxidation with Fenton-like reagents: assays in a pilot plant.

    Science.gov (United States)

    Silva-Castro, Gloria Andrea; Rodelas, Belén; Perucha, Carlos; Laguna, Jaime; González-López, Jesús; Calvo, Concepción

    2013-02-15

    The present study focuses on the remediation of diesel-polluted soil using modified Fenton treatment coupled with inorganic NPK fertilizer ("Fenton+NPK"). Studies were carried out in a pilot plant containing 1 m(3) of sandy soil contaminated with 20,000 mg kg(-1) of diesel, placed outdoors at a temperature ranging between 5 and 10 °C. Results showed that NPK-fertilizer as post-treatment stimulated culturable degrading bacteria and enhanced dehydrogenase activity. Fenton+NPK treatment increased total petroleum hydrocarbon (TPH) removal efficacy. Natural attenuation removed 49% of TPH in the surface layer, 23% of TPH in the non-saturated layer and 4% of the TPH in the saturated layer, while the percentage removed of TPH after Fenton+NPK treatment was 58%, 57% and 32% respectively. The results from our study showed that, immediately after soil contamination, occurred a specialization and differentiation of the bacterial community, but after this initial modification, no significant changes of bacterial diversity was observed under natural attenuation conditions. In contrast, when the Fenton's reagent was applied a reduction of the bacterial biodiversity was observed. However, the post-biostimulation did enhance the degrading microbiota and stimulated their degrading biological activity. In conclusion, biostimulation, as a post-treatment step in chemical oxidation, is an effective solution to remediate hydrocarbon-polluted sites.

  10. Solar photo-Fenton degradation of nalidixic acid in waters and wastewaters of different composition. Analytical assessment by LC-TOF-MS.

    Science.gov (United States)

    Sirtori, Carla; Zapata, Ana; Gernjak, Wolfgang; Malato, Sixto; Lopez, Antonio; Agüera, Ana

    2011-02-01

    This work assessed the solar photo-Fenton degradation of nalidixic acid (NXA), a quinolone antibacterial agent, in several different aqueous solutions. It has been proven that the composition of the water clearly affects the efficiency of the photo-Fenton process. The presence of chlorine ions induces the concurrence of different mechanisms involving Cl() and Cl(2)(-) radicals, which slow down the process. Up to 35 transformation products (TPs) were identified and their structures characterized by accurate LC-TOF-MS mass measurements during treatment of the different model waters. Photocatalytic degradation was thus observed to proceed mainly through the attack of the hydroxyl radicals on the double bond C((2))C((3)) which induce further ring opening. All the TPs identified persisted after total degradation of NXA. NXA in real pharmaceutical effluent was treated by photo-Fenton as a first stage before biological treatment. As NXA has been demonstrated to be recalcitrant to biological treatment, photo-Fenton treatment of the effluent was continued until its total degradation. Although NXA was efficiently degraded, LC-MS analyses demonstrated that some of the TPs identified after the photo-Fenton treatment were also recalcitrant to biological treatment, persisting after the combined treatment. These results show that analytical assessment of photocatalytic water treatments is essential to assure they are functioning as intended.

  11. 铁络合物催化类Fenton氧化研究进展%Progress in the research on iron complex catalyzed Fenton-like oxidation

    Institute of Scientific and Technical Information of China (English)

    郗丽娟; 曹天静; 李大鹏; 杨榕; 徐淑芬; 廖霞; 张瑛洁

    2011-01-01

    The progress in iron complex catalyzed Fenton-like oxidation is reviewed. Compared with iron,the iron complex has a higher catalytic activity to improve the removal rate of organic matter from water. The homogeneous Fenton-like catalyzed by iron complex may bring a problem of removing metallic ions in subsequent process, so the heterogeneous Fenton-like catalyzed by iron complex has a better future. The current research situation of the Fenton-like catalyzed by iron complex loaded on resin is introduced emphatically and the reactive species in the Fenton-like catalyzed by iron complex is discussed.%综述了铁络合物催化类Fenton氧化的研究进展.铁络合物与铁相比具有更高的催化活性,可提高水中有机物的去除效果.均相类Fenton存在后续金属离子的去除问题,因此铁络合物作为催化剂的多相催化类Fenton氧化具有更好的应用前景.重点介绍了高分子负载铁络合物催化类Fenton氧化降解水中有机物的研究现状及铁络合物催化类Fenton氧化的反应活性物种.

  12. Optimization of photo-Fenton process parameters on carbofuran degradation using central composite design.

    Science.gov (United States)

    Lu, Li A; Ma, Ying S; Daverey, Achlesh; Lin, Jih G

    2012-01-01

    Carbofuran, one of the most toxic and biorefractory carbamate compounds, is widely used in insecticides in Taiwan (9-18% of total insecticides production per year). In the present study, a central composite design experiment was used to study the effect of photo-Fenton treatment on carbofuran solution and to optimize the process variables such as carbofuran concentration (1-100 mg L(-1)), H(2)O(2) dosage rate (0.25-6 mg L(-1) min(-1)) and Fe(3+) dosage (1-50 mg L(-1)), which influenced the efficiency of carbofuran degradation and mineralization. The results indicated that all the variables investigated in this study had significant roles in the degradation and mineralization of carbofuran in solution. The carbofuran degradation and mineralization efficiencies were increased with increase in H(2)O(2) dosage rate and Fe(3+) dosage, and with decrease in carbofuran concentration. Furthermore, optimum values of both H(2)O(2) dosage rate and Fe(3+) dosage were found to shift to higher values as carbofuran concentration increased. Based on the model obtained in this study, optimum H(2)O(2) dosage rate and Fe(3+) dosage were found to be 4 mg L(-1) min(-1) and 20 mg L(-1), respectively, for 51 mg L(-1) of carbofuran concentration. Under these conditions, carbofuran was completely removed within 30 min and coupled with 78% mineralization at the end of experiment.

  13. 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.

  14. A comparison of central composite design and Taguchi method for optimizing Fenton process.

    Science.gov (United States)

    Asghar, Anam; Abdul Raman, Abdul Aziz; Daud, Wan Mohd Ashri Wan

    2014-01-01

    In the present study, a comparison of central composite design (CCD) and Taguchi method was established for Fenton oxidation. [Dye]ini, Dye:Fe(+2), H2O2:Fe(+2), and pH were identified control variables while COD and decolorization efficiency were selected responses. L 9 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.

  15. [Modification of activated carbon fiber for electro-Fenton degradation of phenol].

    Science.gov (United States)

    Ma, Nan; Tian, Yao-Jin; Yang, Guang-Ping; Xie, Xin-Yuan

    2014-07-01

    Microwave-modified activated carbon fiber (ACF-1), nitric acid-modified activated carbon fiber (ACF-2), phosphoric acid-modified activated carbon fiber (ACF-3) and ammonia-modified activated carbon fiber (ACF-4) were successfully fabricated. The electro-Fenton catalytic activities of modified activated carbon fiber were evaluated using phenol as a model pollutant. H2O2 formation, COD removal efficiency and phenol removal efficiency were investigated compared with the unmodified activated carbon fiber (ACF-0). Results indicated that ACF-1 showed the best adsorption and electrocatalytic activity. Modification was in favor of the formation of H2O2. The performance of different systems on phenol degradation and COD removal were ACF-1 > ACF-3 > ACF-4 > ACF-2 > ACF-0 and ACF-1 > ACF-4 > ACF-3 > ACF-2 > ACF-0, respectively, which confirmed that electrocatalytic activities of modified activated carbon fiber were better than the unmodified. In addition, phenol intermediates were not the same while using different modified activated carbon fibers.

  16. 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.

  17. 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.

  18. 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.

  19. Pd/RGO modified carbon felt cathode for electro-Fenton removing of EDTA-Ni.

    Science.gov (United States)

    Zhang, Zhen; Zhang, Junya; Ye, Xiaokun; Hu, Yongyou; Chen, Yuancai

    Ethylenediaminetetraacetic acid (EDTA) forms stable complexes with toxic metals such as nickel due to its strong chelation. The electro-Fenton (EF) process using a cathode made from palladium (Pd), reduced graphene oxide (RGO) and carbon felt, fed with air, exhibited high activities and stability for the removal of 10 mg L(-1) EDTA-Ni solution. Pd/RGO catalyst was prepared by one-pot synthesis; the scanning electron microscopy and X-ray diffraction analysis indicated nanoparticles and RGO were well distributed on carbon felt, forming three dimensional architecture with both large macropores and a mesoporous structure. The cyclic voltammetric results showed that the presence of RGO in Pd/RGO/carbon felt significantly increased the current response of two-electron reduction of O2 (0.45 V). The key factors influencing the removal efficiency of EDTA-Ni, such as pH, current and Fe(2+) concentration, were investigated. Under the optimum conditions, the removal efficiency of EDTA-Ni reached 83.8% after 100 min EF treatment. Mechanism analysis indicated that the introduction of RGO in Pd/RGO/carbon felt significantly enhanced the electrocatalytic activities by inducing •OH in the EF process; direct H2O2 oxidation still accounted for a large amount of EDTA-Ni removal efficiency.

  20. Activated sludge treatment by electro-Fenton process: Parameter optimization and degradation mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Rahmani, Ali Reza; Azarian, Ghasem; Berizi, Zohreh [Hamadan University of Medical Sciences, Hamadan (Iran, Islamic Republic of); Nematollahi, Davood [Bu-Ali-Sina University, Hamadan (Iran, Islamic Republic of); Godini, Kazem [Ilam University of Medical Sciences, Ilam (Iran, Islamic Republic of)

    2015-08-15

    This study was conducted to evaluate the mineralization of activated sludge (MAS) by a facile and environmentally friendly electro-Fenton process (EFP). The effects of initial H{sub 2}O{sub 2} concentration, pH value, applied current density and operating time on MAS through determining the removal rate of chemical oxygen demand (COD) and total coliform (TC) were studied. 72% of COD was removed by indirect oxidation double-mediated based on the electro- generation of hydroxyl radical and active chlorine, under the following optimum conditions: 127mmol L{sup -}1 of hydrogen peroxide, pH=3.0, 10 mA cm{sup -}2 of DC current, 120min of operating time, and 0.22mol L{sup -}1 of NaCl as the supporting electrolyte. Only in 10 min and pH 3.0 approximately 100% of TC was removed. The findings indicated that EFP can be applied efficiently for MAS by selecting appropriate operating conditions. The bottom line is that the process is entirely effective owing to the application of green oxidants (hydroxyl radical and active chlorine) and lack of being influenced by environmental situations, which can be introduced as an alternative to current conventional methods.

  1. Electroplating sludge derived zinc-ferrite catalyst for the efficient photo-Fenton degradation of dye.

    Science.gov (United States)

    Cao, Zhenbang; Zhang, Jia; Zhou, Jizhi; Ruan, Xiuxiu; Chen, Dan; Liu, Jianyong; Liu, Qiang; Qian, Guangren

    2017-02-14

    A zinc-dominant ferrite catalyst for efficient degradation of organic dye was prepared by the calcination of electroplating sludge (ES). Characterizations indicated that zinc ferrite (ZnFe2O4) coexisted with Fe2O3 structure was the predominant phase in the calcined electroplating sludge (CES). CES displayed a high decolorization ratio (88.3%) of methylene blue (MB) in the presence of H2O2 combined with UV irradiation. The high efficiency could be ascribed to the photocatalytic process induced by ZnFe2O4 and the photo-Fenton dye degradation by ferrous content, and a small amount of Al and Mg in the sludge might also contribute to the catalysis. Moreover, the degradation capability of dye by CES was supported by the synthetic ZnFe2O4 with different Zn to Fe molar ratio (n(Zn): n(Fe)), as 84.81%-86.83% of dye was removed with n(Zn): n(Fe) ranged from 1:0.5 to 1:3. All synthetic ferrite samples in the simulation achieved adjacent equilibrium decolorization ratio, the flexible proportioning of divalent metal ions (M(2+)) to trivalent metal ions (M(3+)) applied in the synthesis indicated that the catalyst has a high availability. Therefore, an efficacious catalyst for the degradation of dye can potentially be derived from heavy metal-containing ES, it's a novel approach for the reutilization of ES.

  2. Electro-Fenton treatment of mature landfill leachate in a continuous flow reactor.

    Science.gov (United States)

    Zhang, Hui; Ran, Xiaoni; Wu, Xiaogang

    2012-11-30

    The treatment of mature landfill leachate by EF-Fere (also called Fered-Fenton) method was carried out in a continuous stirred tank reactor (CSTR) using Ti/RuO(2)-IrO(2)-SnO(2)-TiO(2) mesh anodes and Ti mesh cathodes. The effects of important parameters, including initial pH, inter-electrode gap, H(2)O(2) to Fe(2+) molar ratio, H(2)O(2) dosage and hydraulic retention time, on COD removal were investigated. The results showed that the complete mixing condition was fulfilled in the electrochemical reactor employed in this study and COD removal followed a modified pseudo-first order kinetic model. The COD removal efficiency increased with the decrease of H(2)O(2) to Fe(2+) molar ratio and hydraulic retention time. There existed an optimal inter-electrode gap or H(2)O(2) dosage so that the highest COD removal was achieved. Nearly the same COD removal was obtained at initial pH 3 and 5, but the steady state was quickly achieved at initial pH 3. The organic pollutants in the leachate were analyzed through a gas chromatography coupled with mass spectrometry (GC-MS) system. About 73 organics were detected in the leachate, and 52 of which were completely removed after EF-Fere process.

  3. Treatment of municipal wastewater treatment plant effluents with modified photo-Fenton as a tertiary treatment for the degradation of micro pollutants and disinfection.

    Science.gov (United States)

    Klamerth, Nikolaus; Malato, Sixto; Agüera, Ana; Fernández-Alba, Amadeo; Mailhot, Gilles

    2012-03-06

    The goal of this paper was to develop a modified photo-Fenton treatment able to degrade micro pollutants in municipal wastewater treatment plant (MWTP) effluents at a neutral pH with minimal iron and H(2)O(2) concentrations. Complexation of Fe by ethylenediamine-N,N'-disuccinic acid (EDDS) leads to stabilization and solubilization of Fe at natural pH. Photo-Fenton experiments were performed in a pilot compound parabolic collector (CPC) solar plant. Samples were treated with solid phase extraction (SPE) and analyzed by HPLC-Qtrap-MS. The rapid degradation of contaminants within the first minutes of illumination and the low detrimental impact on degradation of bicarbonates present in the water suggested that radical species other than HO(•) are responsible for the efficiency of such photo-Fenton process. Disinfection of MWTP effluents by the same process showed promising results, although disinfection was not complete.

  4. Reaction Graph

    Institute of Scientific and Technical Information of China (English)

    傅育熙

    1998-01-01

    The paper proposes reaction graphs as graphical representations of computational objects.A reaction graph is a directed graph with all its arrows and some of its nodes labeled.Computations are modled by graph rewriting of a simple nature.The basic rewriting rules embody the essence of both the communications among processes and cut-eliminations in proofs.Calculi of graphs are ideentified to give a formal and algebraic account of reaction graphs in the spirit of process algebra.With the help of the calculi,it is demonstrated that reaction graphs capture many interesting aspects of computations.

  5. Relevance of a combined process coupling electro-Fenton and biological treatment for the remediation of sulfamethazine solutions – Application to an industrial pharmaceutical effluent

    OpenAIRE

    Mansour, Dorsaf; Fourcade, Florence; Soutrel, Isabelle; Hauchard, Didier; Bellakhal, Nizar; Amrane, Abdeltif

    2014-01-01

    International audience; A combined process coupling an electro-Fenton pretreatment and a biological degradation was implemented in order to mineralize synthetic and industrial pharmaceutical effluents, containing a veterinary antibiotic, sulfamethazine (SMT). The electro-Fenton pretreatment of SMT synthetic solution was first examined and the obtained results showed total SMT degradation after 30 min of electrolysis at pH 3, 18°C, 500 mA and an initial SMT concentration of 0.2 mM, while the l...

  6. 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.

  7. Electrochemically assisted Fenton reaction : reaction of hydroxyl radicals with xenobiotics followed by on-line analysis with high-performance liquid chromatography/tandem mass spectrometry

    NARCIS (Netherlands)

    Jurva, U; Wikstrom, HV; Bruins, AP

    2002-01-01

    Oxygen radicals are generated in vivo by various processes, often as toxic intermediates in different metabolic transformations, and have been shown to play an important role for a large number of diseases. In this article we introduce an electrochemical flow-through system that allows generation of

  8. 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.

  9. Inactivation of natural enteric bacteria in real municipal wastewater by solar photo-Fenton at neutral pH.

    Science.gov (United States)

    Ortega-Gómez, E; Esteban García, B; Ballesteros Martín, M M; Fernández Ibáñez, P; Sánchez Pérez, J A

    2014-10-15

    This study analyses the use of the solar photo-Fenton treatment in compound parabolic collector photo-reactors at neutral pH for the inactivation of wild enteric Escherichia coli and total coliform present in secondary effluents of a municipal wastewater treatment plant (SEWWTP). Control experiments were carried out to find out the individual effects of mechanical stress, pH, reactants concentration, and UVA radiation as well as the combined effects of UVA-Fe and UVA-H2O2. The synergistic germicidal effect of solar-UVA with 50 mg L(-1) of H2O2 led to complete disinfection (up to the detection limit) of total coliforms within 120 min. The disinfection process was accelerated by photo-Fenton, achieving total inactivation in 60 min reducing natural bicarbonate concentration found in the SEWWTP from 250 to 100 mg L(-1) did not give rise to a significant enhancement in bacterial inactivation. Additionally, the effect of hydrogen peroxide and iron dosage was evaluated. The best conditions were 50 mg L(-1) of H2O2 and 20 mg L(-1) of Fe(2+). Due to the variability of the SEWWTP during autumn and winter seasons, the inactivation kinetic constant varied between 0.07 ± 0.04 and 0.17 ± 0.04 min(-1). Moreover, the water treated by solar photo-Fenton fulfilled the microbiological quality requirement for wastewater reuse in irrigation as per the WHO guidelines and in particular for Spanish legislation.

  10. 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.

  11. 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.

  12. Application of SBA-15 in Adsorption-Fenton Oxidation Process for Simultaneous Remediation of Dehp and As(iii)

    Science.gov (United States)

    Latorre, I.; Hwang, S.

    2013-12-01

    Di-2-ethylhexyl phthalate (DEHP) has been widely used as plasticizer in the manufacturing of polymeric materials to enhance flexibility, transparency and softness, particularly, in polyvinyl chloride (PVC) production. Several studies elucidated that DEHP could be linked to hepatocellular tumors and pre-term birth and may be a developmental and reproductive toxicant. Arsenic (As) contamination has been widespread in the environment and because of its toxicity and prevalence in nature; it also has become a significant environmental health concern. Most solid waste materials containing DEHP and As(III) are disposed of in landfills and may migrate to groundwater and soil environments representing a threat to human receptors. Therefore, the application of adsorption-Fenton oxidation process with Fe adsorbed to SBA-15 matrix was assessed for simultaneous remediation of DEHP and As(III). Three sequences were run to assess the regeneration efficiency of the SBA-15. A response surface methodology was employed to optimize adsorption and Fenton regeneration. Adsorption optimization was evaluated with regard to SBA-15 doses and the extent of As(III) and Fe concentrations. Optimization of Fenton regeneration, in addition, assessed initial H2O2 concentration. Global optimization for maximum reduction of DEHP and As(III) was performed by D-Optimal. Highest adsorption of DEHP (90-95%) and As (40-95%) into the SBA-15 was predicted at 1.16 mM Fe, 18.74 mg SBA-15 and 3.71 mg/L As(III). Highest reduction of As (78-99%) and DEHP (90-97%) was predicted with 0.50 mM Fe, 22 mg SBA-15, 3.02 mg/L As(III) and 22.50 mM H2O2. Global optimal treatments were validated and SBA-15 regenerated material was characterized via SEM and XPS. The efficiency of DEHP and As(III) remediation by adsorption-Fenton oxidation process, applying optimal treatment combinations, was evaluated using leachate from a lab scale bioreactor monofill (i.e., filled with PVC materials). Capability of As(III) and DEHP

  13. Influence of the apparent molecular size of humic substances on the efficiency of coagulation using Fenton's reagent

    Directory of Open Access Journals (Sweden)

    MARCELO DE JULIO

    2013-06-01

    Full Text Available This work used Fenton's reagent as a coagulating agent in the treatment of water samples with high true colour caused by humic substances (HS extracted from peat. In addition, the effects of the apparent molecular size of HS on coagulation, flocculation and flotation were studied. To that end, four distinct water samples having the same true colour were prepared using HS with different molecular sizes, which were obtained by ultrafiltration fractioning. Through optimisation of coagulant dosage and coagulation pH, as well as posterior construction of coagulation diagrams for each water sample, it was verified that the sample prepared with the smallest apparent molecular size of HS was the most difficult to treat, requiring higher coagulant (Fenton's reagent dosages than samples prepared with larger HS molecular sizes. Furthermore, filtration experiments after dissolved air flotation (DAF were carried out in an attempt to simulate conventional treatment. The most representative results in filtered water were: apparent colour ≤ 3 HU; turbidity Este trabalho empregou o reagente de Fenton como agente coagulante no tratamento de águas contendo cor elevada causada pela introdução de substâncias húmicas extraídas de turfa. Além disto, foi estudado o efeito do tamanho molecular aparente das substâncias húmicas na eficiência da coagulação, floculação e flotação de águas; para isto foram preparadas quatro águas distintas apresentado a mesma cor verdadeira, mas com substâncias húmicas de diferentes tamanhos moleculares, obtidas por fracionamento por ultrafiltração. Por meio da otimização da dosagem de coagulante e respectivo pH de coagulação e posterior construção dos diagramas de coagulação para cada água de estudo, verificou-se que a água preparada com as substâncias húmicas de menor tamanho molecular aparente apresentou maior grau de dificuldade para tratamento, requerendo dosagens de coagulante (reagente de Fenton bem

  14. Fenton process on single and mixture components of phenothiazine pharmaceuticals: Assessment of intermediaries, fate, and preliminary ecotoxicity.

    Science.gov (United States)

    Wilde, Marcelo L; Schneider, Mandy; Kümmerer, Klaus

    2017-04-01

    Pharmaceuticals do not occur isolated in the environment but in multi-component mixtures and may exhibit antagonist, synergistic or additive behavior. Knowledge on this is still scarce. The situation is even more complicated if effluents or potable water is treated by oxidative processes or such transformations occur in the environment. Thus, determining the fate and effects of parent compounds, metabolites and transformation products (TPs) formed by transformation and degradation processes in the environment is needed. This study investigated the fate and preliminary ecotoxicity of the phenothiazine pharmaceuticals, Promazine (PRO), Promethazine (PRM), Chlorpromazine (CPR), and Thioridazine (THI) as single and as components of the resulting mixtures obtained from their treatment by Fenton process. The Fenton process was carried out at pH7 and by using 0.5-2mgL(-1) of [Fe(2+)]0 and 1-12.5mgL(-1) of [H2O2]0 at the fixed ratio [Fe(2+)]0:[H2O2]0 of 1:10 (w:w). No complete mineralization was achieved. Constitutional isomers and some metabolite-like TPs formed were suggested based on their UHPLC-HRMS(n) data. A degradation pathway was proposed considering interconnected mechanisms such as sulfoxidation, hydroxylation, N-dealkylation, and dechlorination steps. Aerobic biodegradation tests (OECD 301 D and OECD 301 F) were applied to the parent compounds separately, to the mixture of parent compounds, and for the cocktail of TPs present after the treatment by Fenton process. The samples were not readily biodegradable. However, LC-MS analysis revealed that abiotic transformations, such hydrolysis, and autocatalytic transformations occurred. The initial ecotoxicity tested towards Vibrio fischeri as individual compounds featured a reduction in toxicity of PRM and CPR by the treatment process, whereas PRO showed an increase in acute luminescence inhibition and THI a stable luminescence inhibition. Concerning effects of the mixture components, reduction in toxicity by the

  15. Fenton treatment of olive oil mill wastewater--applicability of the method and parameters effects on the degradation process

    Institute of Scientific and Technical Information of China (English)

    Bensalah Nasr; Bedoui Ahmed; Gadri Abdellatif

    2004-01-01

    The low biodegradability of polyphenolic compounds typically found in olive processing indicated that biological treatment is not always successful in the treatment of olive oil mill wastewater in term of COD removal. In this study the results of investigations on the applicability of Fenton's reagent in the treatment of this effluent were discussed. The efficiency of this method was determined. 86 % of removal COD was obtained using 5 mol H2O2 and 0.4 mol Fe2+ per liter of crude OMW. The main parameters that govern the complex reactive system, i.e., time, pH, [H2O2] and [Fe(II)] have been studied.