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Sample records for introduced phenol degradation

  1. (ethylene terephthalate) degradation in phenol

    African Journals Online (AJOL)

    No abstract available. The evaluation of the acid number, ash content and melting temperature of poly (ethylene terephthalate) has been reported (Otaigbe et al, 2003). The polymer was dissolved in phenol: 1,2 dichlorobenzene solvent mixture of 35%: 65% and 50%: 50% by weight and then degraded at 143±2oC.

  2. Identification and genetic characterization of phenol- degrading ...

    African Journals Online (AJOL)

    SAURABH

    2013-02-20

    Feb 20, 2013 ... compared with LmPH gene of Pseudomonas sp.CF600. Reversed phase high performance liquid chromatography showed that the isolate can degrade phenol through catechol ortho fission pathway. In this paper, we reported about the new strain of Acinetobacter sp. capable of degrading phenol (9.5 mM.

  3. Degradation and toxicity reduction of phenol by ultrasound waves ...

    African Journals Online (AJOL)

    The effects of parameters such as pH, kinetic constants and initial phenol concentration on the sonochemical degradation of phenol and toxicity assay were studied. The experimental results showed that lower pH and lower concentration of phenol favor the phenol degradation. But the rates of phenol degradation under ...

  4. DEGRADATION AND TOXICITY REDUCTION OF PHENOL BY ...

    African Journals Online (AJOL)

    a

    WAVES. A. Maleki1*, A.H. Mahvi2, A. Mesdaghinia2 and K. Naddafi2. 1Health Faculty, Kurdistan University of Medical Sciences, Sanandaj, Iran. 2School of Public Health ... advanced oxidation process for the treatment of hazardous contaminants in water. .... Degradation and toxicity reduction of phenol by ultrasound waves.

  5. Isolation and identification of phenol degrading bacteria from Lake ...

    African Journals Online (AJOL)

    The aim of this study is to isolate and identify phenol degrading bacteria from Lake Parishan and to assay their kinetic growth. Sixty samples of water and sedimentation of different area of Lake Parishan were collected. In order to isolate phenol degrading bacteria, samples were cultured on salt base phenol broth media.

  6. Degradation and toxicity reduction of phenol by ultrasound waves

    Directory of Open Access Journals (Sweden)

    A. Maleki

    2007-04-01

    Full Text Available The effects of parameters such as pH, kinetic constants and initial phenol concentration on the sonochemical degradation of phenol and toxicity assay were studied. The experimental results showed that lower pH and lower concentration of phenol favor the phenol degradation. But the rates of phenol degradation under sonication have always been quite low. It is found that the rate of ultrasonic degradation of phenol for initial concentration of 1 mg/L is 0.018 min-1 but later it reduces with increasing of phenol initial concentration substantially and the experimental data fitted well with pseudo first-order reaction rate equation. Bioassay tests showed that phenol was toxic to Daphnia magna and so resulted in quite low LC50 values. Comparison of toxicity units (TU between phenol and effluent toxicity showed that the TU value for effluent was 1.21 times lower than that obtained for phenol solely. Thus, the toxicity of metabolites formed during the degradation of phenol is lower than the toxicity of phenol itself.

  7. Identification and genetic characterization of phenol-degrading ...

    African Journals Online (AJOL)

    A phenol-degrading novel monosodium glutamate was isolated from oil contaminated soil in India. This strain was found capable to utilize and tolerate up to 9.5 mM of phenol. Based on the results of phylogenetic similarity of 16S recombinant ribonucleic acid (rRNA) gene sequences and fatty acid analysis, strain MSG8 was ...

  8. Toxicity of Phenol and Salt on the Phenol-Degrading Pseudomonas aeruginosa Bacterium

    Directory of Open Access Journals (Sweden)

    Samaei

    2016-08-01

    Full Text Available Background Phenolic compounds, phenol and phenol derivatives are environmental contaminants in some industrial effluents. Entrance of such substances into the environment causes severe environmental pollution, especially pollution of water resources. Biological treatment is a method that uses the potential of microorganisms to clean up contaminated environments. Among microorganisms, bacteria play an important role in treating wastewater contaminated with phenol. Objectives This study aimed to examine the effects of Pseudomonas aeruginosa on degradation of phenol in wastewater contaminated with this pollutant. Methods In this method, the growth rate of P. aeruginosa bacteria was investigated using different concentrations of salt and phenol. This is an experimental study conducted as a pilot in a batch reactor with different concentrations of phenol (25, 50, 100, 150, 300 and 600 mg L-1 and salt (0%, 0.5%, 1%, 2.5% and 5% during 9, 12 and 15 hours. During three days, from 5 experimental and 3 control samples, 18 samples were taken a day forming a sample size of 54 samples for each phenol concentration. Given the number of phenol concentrations (n = 6, a total of 324 samples were analyzed using a spectrophotometer at a wavelength of 600 nm. Results The phenol concentration of 600 mg L-1 was toxic for P. aeruginosa. However, at a certain concentration, it acts as a carbon source for P. aeruginosa. During investigations, it was found that increasing the concentration of phenol increases the rate of bacteria growth. The highest bacteria growth rate occurred was at the salt concentration of zero and phenol concentration of 600 mg L-1. Conclusions The findings of the current study indicate that at high concentrations of salt, the growth of bacteria reduces so that it stops at a concentration of 50 mg L-1 (5%. Thus, the bacterium is halotolerant or halophilic. With an increase in phenol concentration, the growth rate increased. Phenol toxicity appears

  9. Aerobic degradation of trichloroethylene by co-metabolism using phenol and gasoline as growth substrates.

    Science.gov (United States)

    Li, Yan; Li, Bing; Wang, Cui-Ping; Fan, Jun-Zhao; Sun, Hong-Wen

    2014-05-22

    Trichloroethylene (TCE) is a common groundwater contaminant of toxic and carcinogenic concern. Aerobic co-metabolic processes are the predominant pathways for TCE complete degradation. In this study, Pseudomonas fluorescens was studied as the active microorganism to degrade TCE under aerobic condition by co-metabolic degradation using phenol and gasoline as growth substrates. Operating conditions influencing TCE degradation efficiency were optimized. TCE co-metabolic degradation rate reached the maximum of 80% under the optimized conditions of degradation time of 3 days, initial OD600 of microorganism culture of 0.14 (1.26×10⁷ cell/mL), initial phenol concentration of 100 mg/L, initial TCE concentration of 0.1 mg/L, pH of 6.0, and salinity of 0.1%. The modified transformation capacity and transformation yield were 20 μg (TCE)/mg (biomass) and 5.1 μg (TCE)/mg (phenol), respectively. Addition of nutrient broth promoted TCE degradation with phenol as growth substrate. It was revealed that catechol 1,2-dioxygenase played an important role in TCE co-metabolism. The dechlorination of TCE was complete, and less chlorinated products were not detected at the end of the experiment. TCE could also be co-metabolized in the presence of gasoline; however, the degradation rate was not high (28%). When phenol was introduced into the system of TCE and gasoline, TCE and gasoline could be removed at substantial rates (up to 59% and 69%, respectively). This study provides a promising approach for the removal of combined pollution of TCE and gasoline.

  10. Aerobic Degradation of Trichloroethylene by Co-Metabolism Using Phenol and Gasoline as Growth Substrates

    Directory of Open Access Journals (Sweden)

    Yan Li

    2014-05-01

    Full Text Available Trichloroethylene (TCE is a common groundwater contaminant of toxic and carcinogenic concern. Aerobic co-metabolic processes are the predominant pathways for TCE complete degradation. In this study, Pseudomonas fluorescens was studied as the active microorganism to degrade TCE under aerobic condition by co-metabolic degradation using phenol and gasoline as growth substrates. Operating conditions influencing TCE degradation efficiency were optimized. TCE co-metabolic degradation rate reached the maximum of 80% under the optimized conditions of degradation time of 3 days, initial OD600 of microorganism culture of 0.14 (1.26 × 107 cell/mL, initial phenol concentration of 100 mg/L, initial TCE concentration of 0.1 mg/L, pH of 6.0, and salinity of 0.1%. The modified transformation capacity and transformation yield were 20 μg (TCE/mg (biomass and 5.1 μg (TCE/mg (phenol, respectively. Addition of nutrient broth promoted TCE degradation with phenol as growth substrate. It was revealed that catechol 1,2-dioxygenase played an important role in TCE co-metabolism. The dechlorination of TCE was complete, and less chlorinated products were not detected at the end of the experiment. TCE could also be co-metabolized in the presence of gasoline; however, the degradation rate was not high (28%. When phenol was introduced into the system of TCE and gasoline, TCE and gasoline could be removed at substantial rates (up to 59% and 69%, respectively. This study provides a promising approach for the removal of combined pollution of TCE and gasoline.

  11. Degradation of phenol and chlorophenols by mixed and pure cultures

    African Journals Online (AJOL)

    The results suggest the feasibility of the use of toxic chemicals as phenols, hexadecane and other chlorophenols as co-substrates in field decontamination processes. The inhibitory effect of PCP is shown, and the influence of a readily degradable ancillary carbon source on the performance of pure cultures is reported, ...

  12. Effect of phenolic compounds released during degradation of Coir ...

    African Journals Online (AJOL)

    This study was carried out to investigate the effect of degraded coir pith based cyanobacterial culture filtrate on Rattus norvegicus. The culture filtrate containing phenolic compound was administered at a rate of 42 mg/Kg for 15 days and its effect on serum glucose, protein, creatinine, urea, uric acid, alkaline phosphate ...

  13. Comparison of AOPs Efficiencies on Phenolic Compounds Degradation

    Directory of Open Access Journals (Sweden)

    Lourdes Hurtado

    2016-01-01

    Full Text Available In this work, a comparison of the performances of different AOPs in the phenol and 4-chlorophenol (4-CP degradation at lab and pilot scale is presented. It was found that, in the degradation of phenol, the performance of a coupled electro-oxidation/ozonation process is superior to that observed by a photo-Fenton process. Phenol removal rate was determined to be 0.83 mg L−1 min−1 for the coupled process while the removal rate for photo-Fenton process was only 0.52 mg L−1 min−1. Regarding 4-CP degradation, the complete disappearance of the molecule was achieved and the efficiency decreasing order was as follows: coupled electro-oxidation/ozonation > electro-Fenton-like process > photo-Fenton process > heterogeneous photocatalysis. Total organic carbon was completely removed by the coupled electro-oxidation/ozonation process. Also, it was found that oxalic acid is the most recalcitrant by-product and limits the mineralization degree attained by the technologies not applying ozone. In addition, an analysis on the energy consumption per removed gram of TOC was conducted and it was concluded that the less energy consumption is achieved by the coupled electro-oxidation/ozonation process.

  14. Isolation and Identification of Phenol Degrader Bacteria from Sirjan Golgohar Mine Effluent

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    Mehdi Hassanshhian

    2016-03-01

    Full Text Available Phenol and phenolic compounds are highly toxic substances that are found as monoaromatic compounds in various industrial effluents from oil refineries, petrochemical plants, (coal mines, and phenol resin plants. Their discharge into the environment, especially in water resources, causes serious toxicity. Traditionally, physicochemical methods have been used for the removal of phenol and phenolic compounds. Nowadays, bioremediation is known to be the best method for phenol removal from wastewater. The objective of the present study was twofold: isolation and identification of phenol degrading bacteria in the effluent from Golgohar Mine in Sirjan. For this purpose, samples were collected from different sections at Golgohar Mine and its effluent. Phenol degrading bacteria were isolated via enrichment of the samples in the Bushnell Hass medium with phenol used as the only source of carbon and energy. The predominant phenol degrader bacteria were selected by measuring turbidity at 600 nm. The bacteria were subsequently identified by amplification of 16S rRNA with specific primers and PCR sequencing. In this study, 17 strains of phenol degrader bacteria were isolated in soil and wastewater samples collected from different zones of the mine. Screening methods confirmed that 4 strains exhibit a better capability for phenol degradation as evidenced by their capability to degrade 0.4 g/l of phenol. Molecular identification showed that these bacteria belong to the species Pesudomonas sp, Nitrratireductor sp., and Salegentibacter sp. The results also show that the effluent from Golgohar Mine in Sirjan contains many phenol degrading bacteria. The use of these bacteria in the treatment process may lead to a significant reduction in phenol pollution in the mineral effluent.

  15. VUV/UV light inducing accelerated phenol degradation with a low electric input.

    Science.gov (United States)

    Li, Mengkai; Wen, Dong; Qiang, Zhimin; Kiwi, John

    2017-01-23

    This study presents the first evidence for the accelerated degradation of phenol by Fenton's reagent in a mini-fluidic VUV/UV photoreaction system (MVPS). A low-pressure mercury lamp used in the MVPS led to a complete degradation of phenol within 4-6 min. The HO˙ and HO 2 ˙ originating from both Fenton's reagent and VUV photolysis of water were identified with suitable radical scavengers. The effects of initial concentrations of phenol, H 2 O 2 and Fe 3+ as well as solution pH on phenol degradation kinetics were examined. Increasing the initial phenol concentration slowed down the phenol degradation, whereas increasing the initial H 2 O 2 or Fe 3+ concentration accelerated the phenol degradation. The optimal solution pH was 3.7. At both 254 and 185 nm, increasing phenol concentration enhanced its absorption for the incident photons. The reaction mechanism for the degradation of phenol was suggested consistent with the results obtained. This study indicates that the VUV/UV photo-Fenton process has potential applications in the treatment of industrial wastewater containing phenol and related aromatic pollutants.

  16. Photocatalytic degradation of Phenol Red using complexes of some transition metals and hydrogen peroxide

    Directory of Open Access Journals (Sweden)

    SAVITRI LODHA

    2008-06-01

    Full Text Available The photocatalytic degradation of Phenol Red was investigated using thiocyanate complexes of iron, copper, cobalt and hydrogen peroxide. The rate of photocatalytic degradation of the dye was followed spectrophotometrically. The effect of the variation of different parameters, such as pH, concentration of the complexes and dye, amount of H2O2 and light intensity on the rate of photocatalytic degradation was also studied. A tentative mechanism for the photocatalytic degradation of Phenol Red is proposed.

  17. Efficient photocatalytic degradation of phenol in aqueous solution by SnO{sub 2}:Sb nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Al-Hamdi, Abdullah M., E-mail: Abdullah.Al.Hamdi@lut.fi [Laboratory of Green Chemistry, Lappeenranta University of Technology, Sammonkatu 12, 50130 Mikkeli (Finland); Chemistry Department, Sultan Qaboos University, P.O. Box 17, 123 Al-Khoudh (Oman); Chair in Nanotechnology, Water Research Center, Sultan Qaboos University, P.O. Box 17, 123 Al-Khoudh (Oman); Sillanpää, Mika [Laboratory of Green Chemistry, Lappeenranta University of Technology, Sammonkatu 12, 50130 Mikkeli (Finland); Bora, Tanujjal [Chair in Nanotechnology, Water Research Center, Sultan Qaboos University, P.O. Box 17, 123 Al-Khoudh (Oman); Dutta, Joydeep [Chair in Nanotechnology, Water Research Center, Sultan Qaboos University, P.O. Box 17, 123 Al-Khoudh (Oman); Functional Materials Division, ICT, KTH Royal Institute of Technology, Isafjordsgatan 22, SE-164 40 KistaStockholm (Sweden)

    2016-05-01

    Highlights: • Sb doped SnO{sub 2} nanoparticles were synthesized using sol–gel process. • Photocatalytic degradation of phenol were studies using SnO{sub 2}:Sb nanoparticles. • Under solar light phenol was degraded within 2 h. • Phenol mineralization and intermediates were investigated by using HPLC. - Abstract: Photodegradation of phenol in the presence of tin dioxide (SnO{sub 2}) nanoparticles under UV light irradiation is known to be an effective photocatalytic process. However, phenol degradation under solar light is less effective due to the large band gap of SnO{sub 2}. In this study antimony (Sb) doped tin dioxide (SnO{sub 2}) nanoparticles were prepared at a low temperature (80 °C) by a sol–gel method and studied for its photocatalytic activity with phenol as a test contaminant. The catalytic degradation of phenol in aqueous media was studied using high performance liquid chromatography and total organic carbon measurements. The change in the concentration of phenol affects the pH of the solution due to the by-products formed during the photo-oxidation of phenol. The photoactivity of SnO{sub 2}:Sb was found to be a maximum for 0.6 wt.% Sb doped SnO{sub 2} nanoparticles with 10 mg L{sup −1} phenol in water. Within 2 h of photodegradation, more than 95% of phenol could be removed under solar light irradiation.

  18. Efficient photocatalytic degradation of phenol in aqueous solution by SnO2:Sb nanoparticles

    International Nuclear Information System (INIS)

    Al-Hamdi, Abdullah M.; Sillanpää, Mika; Bora, Tanujjal; Dutta, Joydeep

    2016-01-01

    Highlights: • Sb doped SnO 2 nanoparticles were synthesized using sol–gel process. • Photocatalytic degradation of phenol were studies using SnO 2 :Sb nanoparticles. • Under solar light phenol was degraded within 2 h. • Phenol mineralization and intermediates were investigated by using HPLC. - Abstract: Photodegradation of phenol in the presence of tin dioxide (SnO 2 ) nanoparticles under UV light irradiation is known to be an effective photocatalytic process. However, phenol degradation under solar light is less effective due to the large band gap of SnO 2 . In this study antimony (Sb) doped tin dioxide (SnO 2 ) nanoparticles were prepared at a low temperature (80 °C) by a sol–gel method and studied for its photocatalytic activity with phenol as a test contaminant. The catalytic degradation of phenol in aqueous media was studied using high performance liquid chromatography and total organic carbon measurements. The change in the concentration of phenol affects the pH of the solution due to the by-products formed during the photo-oxidation of phenol. The photoactivity of SnO 2 :Sb was found to be a maximum for 0.6 wt.% Sb doped SnO 2 nanoparticles with 10 mg L −1 phenol in water. Within 2 h of photodegradation, more than 95% of phenol could be removed under solar light irradiation.

  19. DETECTION OF PHENOL DEGRADING BACTERIA AND PSEUDOMONAS PUTIDA IN ACTIVATED SLUDGE BY POLYMERASE CHAIN REACTION

    Directory of Open Access Journals (Sweden)

    H. Movahedyan ، H. Khorsandi ، R. Salehi ، M. Nikaeen

    2009-04-01

    Full Text Available Phenol is one of the organic pollutants in various industrial wastewaters especially petrochemical and oil refining. Biological treatment is one of the considerable choices for removing of phenol present in these wastewaters. Identification of effective microbial species is considered as one of the important priorities for production of the biomass in order to achieve desirable kinetic of biological reactions. Basic purpose of this research is identification of phenol-degrading Pseudomonas Putida in activated sludge by polymerase chain reaction (PCR that has high speed and specificity. In this research, 10 various colonies of phenol-degrading bacteria were isolated from municipal activated sludge and the rate of phenol removal and growth rate of these bacteria were assessed in different concentrations of phenol (200 – 900 mg/L. Confirmation of the largest subunit of multicomponent phenol hydroxylase (LmPH gene and gene coding the N fragment in Pseudomonas Putida-derived methyl phenol operon (DmpN gene through PCR were used for general identification of phenol-degrading bacteria and Pseudomonas Putida, respectively. Presence of a 600 bp (base pairs bond in all of isolated strains indicated that they contain phenol hydroxylase gene. 6 of 10 isolated bacteria were Pseudomonas Putida because they produced a 199 bp PCR product by DmpN primers. According to PCR results in this study, the best phenol-degrading bacteria that can utilize 500 – 600 mg/L phenol completely after 48 hours incubation, belong to Pseudomonas Putida strains. It is clear that use of isolated bacteria can lead to considerable decrease of treatment time as well as promotion of phenol removal rate.

  20. Inhibition of anaerobic degradation of phenolics and methanogenesis by coal coking wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Fedorak, P.M.; Hrudey, S.E.

    1987-01-01

    Dilutions of a wastewater containing 410 mg/l phenolics (by 4-aminoantipyrine method) from a coal coking process were tested in anaerobic batch cultures to determine whether phenol degradation and subsequent methane production would occur. Phenol was degraded in cultures which contained up to 30% (V/V) wastewater but no methane production could be attributed to the phenol degradation. Higher concentrations of the wastewater severely inhibited methane formation likely due to cyanide which was present in the wastewater at 8.3 mg/l. Exhaustive extraction at neutral pH with diethyl ether could not alleviate this inhibition, suggesting that it was not primarily due to non-polar organic compounds. Although the inclusion of 2500 mg/l activated carbon in the batch cultures improved the methanogenic fermentation, methane yields were still lower then expected for complete phenolic conversion. 17 refs.

  1. Induction and carbon catabolite repression of phenol degradation genes in Rhodococcus erythropolis nad Rhodococcus jostii

    Czech Academy of Sciences Publication Activity Database

    Szököl, Juraj; Rucká, Lenka; Šimčíková, M.; Halada, Petr; Nešvera, Jan; Pátek, Miroslav

    2014-01-01

    Roč. 98, č. 19 (2014), s. 8267-8279 ISSN 0175-7598 R&D Projects: GA MŠk 2B08062; GA ČR(CZ) GAP504/11/0394 Institutional support: RVO:61388971 Keywords : Phenol degradation * Phenol hydroxylase * Rhodococcus erythropolis Subject RIV: EE - Microbiology, Virology Impact factor: 3.337, year: 2014

  2. Variability of Biological Degradation of Phenolic Hydrocarbons in an Aerobic Aquifer Determined by Laboratory Batch Experiments

    DEFF Research Database (Denmark)

    Nielsen, Per Henning; Christensen, Thomas Højlund

    1994-01-01

    The biological aerobic degradation of 7 phenolic hydrocarbons (phenol, o-cresol, o-nitrophenol, p-nitrophenol, 2,6-dichlorophenol, 2,4-dichlorophenol, 4,6-o-dichlorocresol) and 1 aromatic hydrocarbon (nitrobenzene) was studied for 149 days in replicate laboratory batch microcosms with sediment...

  3. Sol-Gel Synthesized Semiconductor Oxides in Photocatalytic Degradation of Phenol

    OpenAIRE

    Maria K. Cherepivska; Roman V. Prihod’ko

    2014-01-01

    Effectiveness of photocatalytic degradation of phenol in aqueous solution using semiconductor oxides (SO) prepared by a sol-gel method was examined. The physical and chemical properties of synthesized catalysts were investigated by X-ray diffraction (XRD), diffuse reflectance UV-Vis spectroscopy (DRS), and N2-adsorption measurements. The optimal conditions of the photocatalytic degradation of phenol using prepared titanium dioxide sample were defined.

  4. Degradation of Phenol in Wastewater with Ozone Produced by Self-design Ozone Generator

    OpenAIRE

    Wang Shibo; Zhong Dongwei; Qu Guangfei; Ning Ping; Quan Jiankang; Chen Xiaotian

    2016-01-01

    The optimized tube’s structure of the self-design ozone generator was made with the double dielectric inner electrode and small metal cones were embedded in the outside electrode. This ozone generator was used for the degradation of phenol in wastewater. The research was studied from ozone gas flow rate, reaction time, the initial pH and concentration of the phenol in wastewater. In addition, the article also discusses the reaction mechanism of ozone degraded the phenol in wastewater. The res...

  5. Identification and characterization of phenol hydroxylase from phenol-degrading Candida tropicalis strain JH8.

    Science.gov (United States)

    Long, Yan; Yang, Sheng; Xie, Zhixiong; Cheng, Li

    2014-09-01

    The gene phhY encoding phenol hydroxylase from Candida tropicalis JH8 was cloned, sequenced, and expressed in Escherichia coli. The gene phhY contained an open reading frame of 2130 bp encoding a polypeptide of 709 amino acid residues. From its sequence analysis, it is a member of a family of flavin-containing aromatic hydroxylases and shares 41% amino acid identity with phenol hydroxylase from Trichosporon cutaneum. The recombinant phenol hydroxylase exists as a homotetramer structure with a native molecular mass of 320 kDa. Recombinant phenol hydroxylase was insensitive to pH treatment; its optimum pH was at 7.6. The optimum temperature for the enzyme was 30 °C, and its activity was rapidly lost at temperatures above 60 °C. Under the optimal conditions with phenol as substrate, the K(m) and V(max) of recombinant phenol hydroxylase were 0.21 mmol·L(-1) and 0.077 μmol·L(-1)·min(-1), respectively. This is the first paper presenting the cloning and expression in E. coli of the phenol hydroxylase gene from C. tropicalis and the characterization of the recombinant phenol hydroxylase.

  6. Potential impact of methyl isobutyl ketone (MIBK) on phenols degradation in an UASB reactor and its degradation properties.

    Science.gov (United States)

    Wang, Wei; Yang, Kai; Sierra, Julian Muñoz; Zhang, Xuedong; Yuan, Shoujun; Hu, Zhenhu

    2017-07-05

    Methyl isobutyl ketone (MIBK) as a solvent is extensively used for the phenols extraction from the wastewater, so it is unavoidable to expose in the effluent due to the solubility and leakage problem. The present study evaluated the impact of MIBK on phenols degradation in an UASB reactor and analyzed its degradation properties. The results indicated that the continuous dosing (0.1gL -1 ) and impact (10gL -1 ) of MIBK had limited effect on phenols removal (1-2% reduction) in the UASB reactor, but the specific methanogenic activity (SMA) values of sludge decreased by 45-75% after MIBK exposure. Anaerobic degradation rate of MIBK fitted well to a pseudo-first-order kinetic equation with respect to the initial concentration of 35mgL -1 (k=0.0115h -1 , R 2 =0.9664). Furthermore, the relative methane generation rate constants of MIBK were 0.00816, 0.00613, 0.00273, and 0.00207d -1 at the initial concentrations of 0.1, 0.5, 5, and 10gL -1 , respectively. MIBK showed higher inhibitory effect on the methanogenesis than on phenols degradation. This study pointed out that the industrial installations should consider the influence of solvent on anaerobic treatment of phenolic wastewater. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Degradation of Phenol in Wastewater with Ozone Produced by Self-design Ozone Generator

    Directory of Open Access Journals (Sweden)

    Wang Shibo

    2016-01-01

    Full Text Available The optimized tube’s structure of the self-design ozone generator was made with the double dielectric inner electrode and small metal cones were embedded in the outside electrode. This ozone generator was used for the degradation of phenol in wastewater. The research was studied from ozone gas flow rate, reaction time, the initial pH and concentration of the phenol in wastewater. In addition, the article also discusses the reaction mechanism of ozone degraded the phenol in wastewater. The results illustrate that the ozone concentration of self-design ozone generator under the pure oxygen flux (1.0 L/min were 7.06 mg/L, compared with the unoptimized ozone, the optimized ozone generator’s efficiency was improved 56.89%; the phenol removal rate was increased as the initial pH increased in wastewater, when pH was 12, the phenol removal rate was 80.17%; GC-MS analysis was adopted to analyze and determine the phenol intermediates. The results illustrate that the major oxidation degradation products of phenol may be p-benzoquinone benzenequinone, 4-cyclopentene-1, 3-dione and diacetone alcohol.

  8. Degradation of Malaysian peatlands decreases levels of phenolics in soil and in leaves of Macaranga pruinosa

    Directory of Open Access Journals (Sweden)

    CATHERINE MARY YULE

    2016-04-01

    Full Text Available Indo-Malaysian tropical peat swamp forests (PSF sequester enormous stores of carbon in the form of phenolic compounds, particularly lignin as well as tannins. These phenolic compounds are crucial for ecosystem functioning in PSF through their inter-related roles in peat formation and plant defenses. Disturbance of PSF causes destruction of the peat substrate, but the specific impact of disturbance on phenolic compounds in peat and its associated vegetation has not previously been examined. A scale was developed to score peatland degradation based on the three major human impacts that affect tropical PSF – logging, drainage and fire. The objectives of this study were to compare the amount of phenolic compounds in Macaranga pruinosa, a common PSF tree, and in the peat substrate along a gradient of peatland degradation from pristine peat swamp forest to cleared, drained and burnt peatlands. We examined phenolic compounds in M. pruinosa and in peat and found that levels of total phenolic compounds and total tannins decrease in the leaves of M.pruinosa and also in the surface peat layers with an increase in peatland degradation. We conclude that waterlogged conditions preserve the concentration of phenolic compounds in peat, and that even PSF that has been previously logged but which has recovered a full canopy cover will have high levels of total phenolic content (TPC in peat. High levels of TPC in peat and in the flora are vital for the inhibition of decomposition of organic matter and this is crucial for the accretion of peat and the sequestration of carbon. Thus regional PSF flourish despite the phenolic rich, toxic, waterlogged, nutrient poor, conditions, and reversal of such conditions is a sign of degradation.

  9. The degradation of kraft lignin during hydrothermal treatment for phenolics

    Directory of Open Access Journals (Sweden)

    Tang Kai

    2015-09-01

    Full Text Available Kraft lignin was hydrothermally depolymerized at low temperature/short time in water for producing value-added phenolics. The effects of residence time (15, 60 min and reaction temperature (130, 180, 230ºC on yields of oils and phenolic compounds were studied in detail. Total oil yield was found to range between 7% and 10%. The compositions of oils were analyzed by GC-MS to confirm the main compound to be guaiacol (2-methoxy phenol in the range of 12–55% of oil depending on different reaction conditions. The most interesting was the finding that maximum value of total oil yield (10% of kraft lignin and guaiacol amount (55% of oil was obtained at 130ºC/15, 60 min which is a low reaction temperature/short time, while the residual kraft lignins were analyzed by FTIR with respect to the conversion mechanism of kraft lignin by this process.

  10. Kinetics of batch microbial degradation of phenols by indigenous ...

    African Journals Online (AJOL)

    The potential of various organisms to metabolize organic compounds has been observed to be a potentially effective means in disposing of hazardous and toxic wastes. Phenolic compounds have long been recognized as one of the most recalcitrant and persistent organic chemicals in the environment. The bioremediation ...

  11. Effect of phenolic compounds released during degradation of Coir ...

    African Journals Online (AJOL)

    MICHAEL

    mice by 63%, curcumin induced a similar inhibition but quercertin and rutin failed to alter tumor formation at dietary level of 2% carcin. Lin and Chin (2007) reported phenolic compounds are widely present in the plant kingdom. Many epidemiological studies have indicated that consumption of some plant derived food stuffs ...

  12. Substrate inhibition kinetics of phenol degradation by binary mixed ...

    African Journals Online (AJOL)

    Steady states of a continuous culture with an inhibitory substrate were used to estimate kinetic parameters under substrate limitation (chemo stat operation). Mixed cultures of an indigenous Pseudomonas fluorescence and Pseudomonas aeruginosa were grown in continuous culture on phenol as the sole source of carbon ...

  13. Substrate inhibition kinetics of phenol degradation by binary mixed ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-11-05

    Nov 5, 2008 ... Steady states of a continuous culture with an inhibitory substrate were used to estimate kinetic parameters under substrate limitation (chemo stat operation). Mixed cultures of an indigenous. Pseudomonas fluorescence and Pseudomonas aeruginosa were grown in continuous culture on phenol as the sole ...

  14. Optimization of phenol degradation by Candida tropicalis Z-04 using Plackett-Burman design and response surface methodology.

    Science.gov (United States)

    Zhou, Jiangya; Yu, Xiaojuan; Ding, Cong; Wang, Zhiping; Zhou, Qianqian; Pao, Hao; Cai, Weimin

    2011-01-01

    Statistical experimental designs were used to optimize the process of phenol degradation by Candida tropicalis Z-04, isolated from phenol-degrading aerobic granules. The most important factors influencing phenol degradation (p Plackett-Burman design with 11 variables, were yeast extract, phenol, inoculum size, and temperature. Steepest ascent method was undertaken to determine the optimal regions of these four significant factors. Central composite design (CCD) and response surface analysis were adopted to further investigate the mutual interactions between these variables and to identify their optimal values that would generate maximum phenol degradation. The analysis results indicated that interactions between yeast extract and temperature, phenol and temperature, inoculum size and temperature affected the response variable (phenol degradation) significantly. The predicted results showed that the maximum removal efficiency of phenol (99.10%) could be obtained under the optimum conditions of yeast extract 0.41 g/L, phenol 1.03 g/L, inoculum size 1.43% (V/V) and temperature 30.04 degrees C. These predicted values were further verified by validation experiments. The excellent correlation between predicted and experimental values confirmed the validity and practicability of this statistical optimum strategy. This study indicated the excellent ability of C. tropicalis Z-04 in degrading high-strength phenol. Optimal conditions obtained in this experiment laid a solid foundation for further use of this microorganism in the treatment of high-strength phenol effluents.

  15. Degradation and mineralization of phenol compounds with goethite catalyst and mineralization prediction using artificial intelligence.

    Directory of Open Access Journals (Sweden)

    Farhana Tisa

    Full Text Available The efficiency of phenol degradation via Fenton reaction using mixture of heterogeneous goethite catalyst with homogeneous ferrous ion was analyzed as a function of three independent variables, initial concentration of phenol (60 to 100 mg /L, weight ratio of initial concentration of phenol to that of H2O2 (1: 6 to 1: 14 and, weight ratio of initial concentration of goethite catalyst to that of H2O2 (1: 0.3 to 1: 0.7. More than 90 % of phenol removal and more than 40% of TOC removal were achieved within 60 minutes of reaction. Two separate models were developed using artificial neural networks to predict degradation percentage by a combination of Fe3+ and Fe2+ catalyst. Five operational parameters were employed as inputs while phenol degradation and TOC removal were considered as outputs of the developed models. Satisfactory agreement was observed between testing data and the predicted values (R2Phenol = 0.9214 and R2TOC= 0.9082.

  16. Kinetics of Phenol Degradation in Aqueous Solution Oxidized under Low Frequency Ultrasonic Irradiation

    Directory of Open Access Journals (Sweden)

    Marwan Marwan

    2014-06-01

    Full Text Available Phenol is categorized as a refractory pollutant and its presence in water stream is strictly limited according to the government regulation. The present study investigated the degra-dation of phenol in aqueous solution by the effect of ultrasound. The process took place in a 500 ml glass reactor equipped with magnetic stirring and irradiated by low frequency (28 kHz ultrasound from a horn type probe. Ultrasonic irradiation was found to enhance oxidation rates at ambient conditions, compared to other approaches. Optimum conditions were observed at a stirring speed of 400 rpm and temperature of 30 C in acidic solution. It was revealed that the phenol degradation was the first order kinetics with respect to phenol. A low value of the activation energy 6.04 kcal/mol suggested that diffusional steps were rate determining during the phenol decomposition. It also confirmed that phenol was mostly degraded in the film region and less occurred in the bulk solution.

  17. Switching Oxygen Reduction Pathway by Exfoliating Graphitic Carbon Nitride for Enhanced Photocatalytic Phenol Degradation.

    Science.gov (United States)

    Zhang, Hui; Guo, Liang-Hong; Zhao, Lixia; Wan, Bin; Yang, Yu

    2015-03-19

    The selectivity of molecular oxygen activation on the exfoliated graphitic carbon nitride (g-C3N4) and its influence on the photocatalytic phenol degradation process were demonstrated. Compared with bulk g-C3N4, the exfoliated nanosheet yielded a 3-fold enhancement in photocatalytic phenol degradation. ROS trapping experiments demonstrated that although the direct hole oxidation was mainly responsible for phenol photodegradation on both g-C3N4 catalysts, molecular oxygen activation processes on their surface greatly influenced the whole phenol degradation efficiency. Reactive oxygen species and Raman spectroscopy measurements revealed that oxygen was preferentially reduced to ·O2(-) by one-electron transfer on bulk g-C3N4, while on g-C3N4 nanosheet the production of H2O2 via a two-electron transfer process was favored due to the rapid formation of surface-stabilized 1,4-endoperoxide. The latter process not only promotes the separation of photogenerated electron-hole pairs but also greatly facilitates reactive oxygen species formation and subsequently enhances phenol degradation.

  18. Controlled Defects of Zinc Oxide Nanorods for Efficient Visible Light Photocatalytic Degradation of Phenol

    Directory of Open Access Journals (Sweden)

    Jamal Al-Sabahi

    2016-03-01

    Full Text Available Environmental pollution from human and industrial activities has received much attention as it adversely affects human health and bio-diversity. In this work we report efficient visible light photocatalytic degradation of phenol using supported zinc oxide (ZnO nanorods and explore the role of surface defects in ZnO on the visible light photocatalytic activity. ZnO nanorods were synthesized on glass substrates using a microwave-assisted hydrothermal process, while the surface defect states were controlled by annealing the nanorods at various temperatures and were characterized by photoluminescence and X-ray photoelectron spectroscopy. High performance liquid chromatography (HPLC was used for the evaluation of phenol photocatalytic degradation. ZnO nanorods with high surface defects exhibited maximum visible light photocatalytic activity, showing 50% degradation of 10 ppm phenol aqueous solution within 2.5 h, with a degradation rate almost four times higher than that of nanorods with lower surface defects. The mineralization process of phenol during degradation was also investigated, and it showed the evolution of different photocatalytic byproducts, such as benzoquinone, catechol, resorcinol and carboxylic acids, at different stages. The results from this study suggest that the presence of surface defects in ZnO nanorods is crucial for its efficient visible light photocatalytic activity, which is otherwise only active in the ultraviolet region.

  19. The effects of hydrogen peroxide on the sonochemical degradation of phenol and bisphenol A.

    Science.gov (United States)

    Lim, Myunghee; Son, Younggyu; Khim, Jeehyeong

    2014-11-01

    This report describes the effects of H2O2 concentration (0.01, 0.1, 1, and 10mM) on the sonochemical degradation of phenol and bisphenol A (BPA) using an ultrasonic source of 35kHz and 0.08W/mL. The concentration of the target pollutants (phenol or BPA), total organic carbon (TOC), and H2O2 were monitored for each input concentration of H2O2. The effects of H2O2 on the sonochemical degradation of phenol was more significant than that of BPA because phenol has a high solubility and low octanol-water partition coefficient (Kow) value and is subsequently very likely to remain in the aqueous phase, giving it a greater probability of reacting with H2O2. The removal of TOC was also enhanced by the addition of H2O2. Some intermediates of BPA have a high Kow value and subsequently have a greater probability of pyrolyzing by the high temperatures and pressures inside of cavitation bubbles. Thus the removal efficiency of TOC in BPA was higher than that of phenol. The removal efficiencies of TOC were lower than the degradation efficiencies of phenol and BPA. This result is due to the fact that some intermediates cannot readily degrade during the sonochemical reaction. The H2O2 concentration decreased but was not completely consumed during the sonochemical degradation of pollutants. The initial H2O2 concentration and the physical/chemical characteristics of pollutants were considered to be important factors in determining the formation rate of the H2O2. When high concentration of H2O2 was added to the solution, the formation rates were relatively low compared to when low concentrations of H2O2 were used. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Isolation and characterization of phenol degrading bacterium strain Bacillus thuringiensis J20 from olive waste in Palestine.

    Science.gov (United States)

    Ereqat, Suheir I; Abdelkader, Ahmad A; Nasereddin, Abedelmajeed F; Al-Jawabreh, Amer O; Zaid, Taher M; Letnik, Ilya; Abdeen, Ziad A

    2018-01-02

    This study aimed at isolation of phenol degrading bacteria from olive mill wastes in Palestine. The efficiency of phenol removal and factors affecting phenol degradation were investigated. A bacterial strain (J20) was isolated from solid olive mill waste and identified as Bacillus thuringiensis based on standard morphological, biochemical characteristics and 16SrRNA sequence analysis. The strain was able to grow in a phenol concentration of 700 mg/L as the sole carbon and energy source. The culture conditions showed a significant impact on the ability of these cells to remove phenol. This strain exhibited optimum phenol degradation performance at pH 6.57 and 30 °C . Under the optimized conditions, this strain could degrade 88.6% of phenol (700 mg/L) within 96 h when the initial cell density was OD 600 0.2. However, the degradation efficiency could be improved from about 88% to nearly 99% by increasing the cell density. Immobilization of J20 was carried out using 4% sodium alginate. Phenol degradation efficiency of the immobilized cells of J20 was higher than that of the free cells, 100% versus 88.6% of 700 mg/L of phenol in 120 h, indicating the improved tolerance of the immobilized cells toward phenol toxicity. The J20 was used in detoxifying crude OMWW, phenolic compounds levels were reduced by 61% compared to untreated OMWW after five days of treatment. Hence, B. thuringiensis-J20 can be effectively used for bioremediation of phenol-contaminated sites in Palestine. These findings may lead to new biotechnological applications for the degradation of phenol, related to olive oil production.

  1. Host-vector system for phenol-degrading Rhodococcus erythropolis based on Corynebacterium plasmids

    Czech Academy of Sciences Publication Activity Database

    Veselý, Martin; Pátek, Miroslav; Nešvera, Jan; Čejková, A.; Masák, J.; Jirků, V.

    2003-01-01

    Roč. 61, - (2003), s. 523-527 ISSN 0175-7598 R&D Projects: GA ČR GA526/01/0177 Institutional research plan: CEZ:AV0Z5020903 Keywords : phenol-degrading * rhodococcus * erythropolis Subject RIV: EE - Microbiology, Virology Impact factor: 2.034, year: 2003

  2. Host-vector system for phenol-degrading Rhodococcus erythropolis based on Corynebacterium plasmids

    Czech Academy of Sciences Publication Activity Database

    Veselý, Martin; Pátek, Miroslav; Nešvera, Jan; Čejková, A.; Masák, J.; Jirků, V.

    2003-01-01

    Roč. 61, - (2003), s. 523-527 ISSN 0175-7598 R&D Projects: GA AV ČR IPP1050128; GA ČR GA526/01/0177 Institutional research plan: CEZ:AV0Z5020903 Keywords : phenol-degrading * rhodococcus erythropolis Subject RIV: EE - Microbiology, Virology Impact factor: 2.034, year: 2003

  3. Continuous aerobic phenol degradation by defined mixed immobilized cultutre in packed bed reactors

    Czech Academy of Sciences Publication Activity Database

    Páca jr., J.; Páca, J.; Kostečková, A.; Stiborová, M.; Sobotka, Miroslav; Gerrard, A. M.; Soccol, C. R.

    2005-01-01

    Roč. 50, č. 4 (2005), s. 301-308 ISSN 0015-5632 R&D Projects: GA ČR GA104/03/0407 Institutional research plan: CEZ:AV0Z50200510 Keywords : phenol degradation * pseudomonas putida * commamonas testosteroni Subject RIV: EE - Microbiology, Virology Impact factor: 0.918, year: 2005

  4. related strain capable of degradation of phenol from oil ...

    African Journals Online (AJOL)

    SAM

    2014-04-02

    Apr 2, 2014 ... College of Chemical and Environmental Engineering, Shandong University of Science and Technology, Qingdao,. Shandong, 266590, China. ... tant in water and soil (Jiang et al., 2005). The biological degradation is ... Unavoidable oil leak in the processes of oil extraction and transport caused the serious ...

  5. Degradation of phenols in olive oil mill wastewater by biological, enzymatic, and photo-Fenton oxidation.

    Science.gov (United States)

    Justino, Celine; Marques, Ana Gabriela; Duarte, Kátia Reis; Duarte, Armando Costa; Pereira, Ruth; Rocha-Santos, Teresa; Freitas, Ana Cristina

    2010-03-01

    Olive oil mill wastewater (OOMW) environmental impacts minimization have been attempted by developing more effective processes, but no chemical or biological treatments were found to be totally effective to mitigate their impact on receiving systems. This work is the first that reports simultaneously the efficiency of three different approaches: biological treatment by two fungal species (Trametes versicolor or Pleurotus sajor caju), enzymatic treatment by laccase, and chemical treatment by photo-Fenton oxidation on phenols removal. Those treatments were performed on OOMW with or without phenol supplement (p-coumaric, vanillin, guaiacol, vanillic acid, or tyrosol). OOMW samples resulted from treatments were extracted for phenols using liquid-liquid extraction and analyzed by gas chromatography coupled to mass spectrometry. Treatment with T. versicolor or P. sajor caju were able to remove between 22% and 74% and between 8% and 76% of phenols, respectively. Treatment by laccase was able to reduce 4% to 70% of phenols whereas treatment by photo-Fenton oxidation was responsible for 100% phenols reduction. Range of phenol degradation was equivalent between T. versicolor, P. sajor caju and laccase for p-coumaric, guaiacol, caffeic acid, and tyrosol in supplemented OOMW, which enhances this enzyme role in the biological treatment promoted by these two species. Phenols were removed more efficiently by photo-Fenton treatment than by biological or enzymatic treatments. Use of fungi, laccase, or photo-Fenton presents great potential for removing phenols from OOMW. This should be further assessed by increasing the application scale and the reactor configurations effect on the performance, besides a toxicity evaluation of treated wastewater in comparison to raw wastewater.

  6. Arsenite oxidation-enhanced photocatalytic degradation of phenolic pollutants on platinized TiO2.

    Science.gov (United States)

    Kim, Jaesung; Kim, Jungwon

    2014-11-18

    The effect of As(III) on the photocatalytic degradation of phenolic pollutants such as 4-chlorophenol (4-CP) and bisphenol A (BPA) in a suspension of platinized TiO2 (Pt/TiO2) was investigated. In the presence of As(III), the photocatalytic degradation of 4-CP and BPA was significantly enhanced, and the simultaneous oxidation of As(III) to As(V) was also achieved. This positive effect of As(III) on the degradation of phenolic pollutants is attributed to the adsorption of As(V) (generated from As(III) oxidation) on the surface of Pt/TiO2, which facilitates the production of free OH radicals ((•)OHf) that are more reactive than surface-bound OH radicals ((•)OHs) toward phenolic pollutants. The generation of (•)OHf was indirectly verified by using coumarin as an OH radical trapper and comparing the yields of coumarin--OH adduct (i.e., 7-hydroxycoumarin) formed in the absence and presence of As(V). In repeated cycles of 4-CP degradation, the degradation efficiency of 4-CP gradually decreased in the absence of As(III), whereas it was mostly maintained in the presence of As(III), which was either initially present or repeatedly injected at the beginning of each cycle. The positive effect of As(III) on 4-CP degradation was observed over a wide range of As(III) concentrations (up to mM levels) with Pt/TiO2. However, a high concentration of As(III) (hundreds of μM) inhibited the degradation of 4-CP with bare TiO2. Therefore, Pt/TiO2 can be proposed as a practical photocatalyst for the simultaneous oxidation of phenolic pollutants and As(III) in industrial wastewaters.

  7. Optimization of phenol degradation by the microalga Chlorella pyrenoidosa using Plackett-Burman Design and Response Surface Methodology.

    Science.gov (United States)

    Dayana Priyadharshini, S; Bakthavatsalam, A K

    2016-05-01

    Statistical optimization designs were used to optimize the phenol degradation using Chlorella pyrenoidosa. The important factor influencing phenol degradation was identified by two-level Plackett-Burman Design (PBD) with five factors. PBD determined the following three factors as significant for phenol degradation viz. algal concentration, phenol concentration and reaction time. CCD and RSM were applied to optimize the significant factors identified from PBD. The results obtained from CCD indicated that the interaction between the concentration of algae and phenol, phenol concentration and reaction time and algal concentration and reaction time affect the phenol degradation (response) significantly. The predicted results showed that maximum phenol degradation of 97% could be achieved with algal concentration of 4g/L, phenol concentration of 0.8g/L and reaction time of 4days. The predicted values were in agreement with experimental values with coefficient of determination (R(2)) of 0.9973. The model was validated by subsequent experimentations at the optimized conditions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Phenol degradation by TiO2 photocatalysts combined with different pulsed discharge systems.

    Science.gov (United States)

    Zhang, Yi; Lu, Jiani; Wang, Xiaoping; Xin, Qing; Cong, Yanqing; Wang, Qi; Li, Chunjuan

    2013-11-01

    Films of TiO2 nanotubes distributed over the inner surface of a discharge reactor cylinder (CTD) or adhered to a stainless steel electrode surface (PTD) in a discharge reactor were compared with a single-discharge (SD) system to investigate their efficiencies in phenol degradation. Morphology studies indicated that the TiO2 film was destroyed in the PTD system, but that there was no change in the CTD system after discharge. X-ray diffraction results revealed that the anatase phase of the original sample was preserved in the CTD system, but that an anatase-to-rutile phase transformation occurred in the PTD system after discharge. The highest efficiencies of phenol degradation and total organic carbon (TOC) mineralization were observed in the CTD system, and there was no decrease in phenol degradation efficiency upon reuse of a TiO2 film, indicating high catalysis activity and stability of the TiO2 photocatalysts in the combined treatment. TiO2 photocatalysts favored the formation of hydrogen peroxide and disfavored the formation of ozone. A greater degree of oxidation of intermediates and higher energy efficiency in phenol oxidation were observed with the TiO2-plasma systems, especially in the CTD system, compared to those with the SD system. Copyright © 2013 Elsevier Inc. All rights reserved.

  9. Enhanced degradation of phenol by Sphingomonas sp. GY2B with resistance towards suboptimal environment through adsorption on kaolinite.

    Science.gov (United States)

    Gong, Beini; Wu, Pingxiao; Huang, Zhujian; Li, Yuewu; Dang, Zhi; Ruan, Bo; Kang, Chunxi; Zhu, Nengwu

    2016-04-01

    The effects of clay minerals on microbial degradation of phenol under unfavorable environmental conditions were investigated. Degradation of phenol by Sphingomonas sp. GY2B adsorbed on kaolinite, montmorillonite, and vermiculite were evaluated in comparison with free bacteria under optimal conditions. Kaolinite was found to be the most effective in accelerating degradation rate (reducing the degradation time) as well as improving degradation efficiency (increasing the percentage of phenol degraded), with GY2B/kaolinite complex achieving a degradation efficiency of 96% within 6 h. GY2B adsorbed on kaolinite was more competent than free GY2B in degradation under conditions with high phenol concentrations and at alkaline pH. Kaolinite reduced the time required for degradation by 8-12 h and improved the degradation efficiency by as much as 82% at high phenol concentrations. Meanwhile, the GY2B/kaolinite complex reduced the degradation time by 24 h and improved the degradation efficiency by 46% at pH 12. The improvement was partially due to the buffering effects of kaolinite. It was also shown that Cr(VI) and kaolinite synergistically enhanced the degradation by GY2B, with Cr(VI) and kaolinite both increasing the degradation rate and kaolinite being primarily responsible for enhanced degradation efficiency. These results showed one of the common clay minerals, kaolinite, is able to significantly improve the microbial degradation performance, and protect microorganisms against unfavorable environment. Kaolinite can collaborate with Cr(VI) to further improve the microbial degradation performance. It is implied that clay minerals have great potential to be applied in enhancing the biodegradation of phenol. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Gamma irradiation-induced complete degradation and mineralization of phenol in aqueous solution: Effects of reagent

    Energy Technology Data Exchange (ETDEWEB)

    Alkhuraiji, Turki S., E-mail: khuraiji@kacst.edu.sa [King Abdulaziz City for Science and Technology—KACST, Nuclear Science Research Institute, National Center for Irradiation Technology, P. O. BOX 6086, Riyadh 11442 (Saudi Arabia); Boukari, Sahidou O.B. [Université de Poitiers (France); Alfadhl, Fadhl S. [King Abdulaziz City for Science and Technology—KACST, Nuclear Science Research Institute, National Center for Irradiation Technology, P. O. BOX 6086, Riyadh 11442 (Saudi Arabia)

    2017-04-15

    Highlights: • Ionizing radiation effectively mineralizes phenol in aqueous solution. • Radiolytic system improves when O{sub 3}, H{sub 2}O{sub 2}, N{sub 2}O, O{sub 2}, or S{sub 2}O{sub 8}{sup 2−} is combined with γ-rays. • Radiation chemical yield, dose constant, and dose for 90% degradation are discussed. • Removal/mineralization yields increase with initial concentration of H{sub 2}O{sub 2} or S{sub 2}O{sub 8}{sup 2−}. • Initial pH and inorganic salts have an impact on phenol degradation. - Abstract: This study aims to gain new insight into phenol degradation and mineralization in aqueous solution using ionizing radiation to control its radiolytic elimination under various experimental conditions and to present the different radical reactions involved in water radiolysis. The most obvious finding of this study is that the combination of a reagent, i.e., O{sub 3}, H{sub 2}O{sub 2}, N{sub 2}O, O{sub 2,} or S{sub 2}O{sub 8}{sup 2−}, with γ-rays effectively enhances the radiolytic system for phenol degradation or mineralization. Radiolytic yield is higher with H{sub 2}O{sub 2} than with S{sub 2}O{sub 8}{sup 2−}. For the γ-ray/free O{sub 2}, γ-ray/H{sub 2}O{sub 2}, γ-ray/S{sub 2}O{sub 8}{sup 2−}, γ-ray/N{sub 2}O, and γ-ray/N{sub 2} systems, the absorbed doses for 90% phenol elimination are 1.7, 0.85, 1.65, 1.2, and 6.4 kGy, respectively; in contrast, phenol can be decomposed totally and directly via reaction with molecular ozone. The lowest dose constant for phenol removal is determined for γ-ray/HCO{sub 3}{sup −}. 89% of mineralization is reached for an absorbed dose of 10 kGy with a γ-ray/S{sub 2}O{sub 8}{sup 2−} combination.

  11. Phenols

    Energy Technology Data Exchange (ETDEWEB)

    Hirschberger, W.

    1942-10-22

    The damand for phenol greatly increased after the development of synthetics. The only source for their production was coal. The amount obtained depended greatly on the temperature at which the coal had been treated. The phenol content of low-temperature carbonization tars was higher than from high-temperature coke ovens and the temperatures used in hydrogenation had been found to be particularly advantageous. The yields, referred to coal, were about forty times as high with pressure hydrogenation as from coke ovens. Calculated to the coal used, 4% to 5% useful phenols were obtained during coal hydrogenation and these consisted of about 20% phenols, 35% cresols, and 45% xylenols. The proportion was similar with brown coal, but the recovery of the pure materials was made more difficult by the presence of other oxygenated substances. The most common method of phenol production from oils and the off-waters was the extraction with sodium hydroxide, followed by setting the phenols free with carbon dioxide. The phenosolvan process (extraction with water and distillation), the tricresyl phosphate process, the Fresol process (with methyl alcohol), and the method of extraction with superheated steam were also discussed. Leuna was the only hydrogenation works that recovered phenols on an industrial scale.

  12. Strategy of Pseudomonas pseudoalcaligenes C70 for effective degradation of phenol and salicylate.

    Directory of Open Access Journals (Sweden)

    Merike Jõesaar

    Full Text Available Phenol- and naphthalene-degrading indigenous Pseudomonas pseudoalcaligenes strain C70 has great potential for the bioremediation of polluted areas. It harbours two chromosomally located catechol meta pathways, one of which is structurally and phylogenetically very similar to the Pseudomonas sp. CF600 dmp operon and the other to the P. stutzeri AN10 nah lower operon. The key enzymes of the catechol meta pathway, catechol 2,3-dioxygenase (C23O from strain C70, PheB and NahH, have an amino acid identity of 85%. The metabolic and regulatory phenotypes of the wild-type and the mutant strain C70ΔpheB lacking pheB were evaluated. qRT-PCR data showed that in C70, the expression of pheB- and nahH-encoded C23O was induced by phenol and salicylate, respectively. We demonstrate that strain C70 is more effective in the degradation of phenol and salicylate, especially at higher substrate concentrations, when these compounds are present as a mixture; i.e., when both pathways are expressed. Moreover, NahH is able to substitute for the deleted PheB in phenol degradation when salicylate is also present in the growth medium. The appearance of a yellow intermediate 2-hydroxymuconic semialdehyde was followed by the accumulation of catechol in salicylate-containing growth medium, and lower expression levels and specific activities of the C23O of the sal operon were detected. However, the excretion of the toxic intermediate catechol to the growth medium was avoided when the growth medium was supplemented with phenol, seemingly due to the contribution of the second meta pathway encoded by the phe genes.

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

    Science.gov (United States)

    Pontes, Ricardo F F; Moraes, José E F; Machulek, Amilcar; Pinto, José M

    2010-04-15

    The objective of this paper is to develop and validate a mechanistic model for the degradation of phenol by the Fenton process. Experiments were performed in semi-batch operation, in which phenol, catechol and hydroquinone concentrations were measured. Using the methodology described in Pontes and Pinto [R.F.F. Pontes, J.M. Pinto, Analysis of integrated kinetic and flow models for anaerobic digesters, Chemical Engineering Journal 122 (1-2) (2006) 65-80], a stoichiometric model was first developed, with 53 reactions and 26 compounds, followed by the corresponding kinetic model. Sensitivity analysis was performed to determine the most influential kinetic parameters of the model that were estimated with the obtained experimental results. The adjusted model was used to analyze the impact of the initial concentration and flow rate of reactants on the efficiency of the Fenton process to degrade phenol. Moreover, the model was applied to evaluate the treatment cost of wastewater contaminated with phenol in order to meet environmental standards. 2009 Elsevier B.V. All rights reserved.

  14. Rate limiting factors in trichloroethylene co-metabolic degradation by phenol-grown aerobic granules.

    Science.gov (United States)

    Zhang, Yi; Tay, Joo Hwa

    2014-04-01

    The potential of aerobic granular sludge in co-metabolic removal of recalcitrant substances was evaluated using trichloroethylene (TCE) as the model compound. Aerobic granules cultivated in a sequencing batch reactor with phenol as the growth substrate exhibited TCE and phenol degradation activities lower than previously reported values. Depletion of reducing energy and diffusion limitation within the granules were investigated as the possible rate limiting factors. Sodium formate and citrate were supplied to the granules in batch studies as external electron sources. No significant enhancing effect was observed on the instant TCE transformation rates, but 10 mM formate could improve the ultimate transformation capacity by 26 %. Possible diffusion barrier was studied by sieving the biomass into five size fractions, and determining their specific TCE and phenol degradation rates and capacities. Biomass in the larger size fractions generally showed lower activities. Large granules of >700 μm diameter exhibited only 22 % of the flocs' TCE transformation capacity and 35 % of its phenol dependent SOUR, indicating the possible occurrence of diffusion limitation in larger biomass. However, the highest specific TCE transformation rate was observed with the fraction that mostly consisted of small granules (150-300 μm), suggesting an optimal size range while applying aerobic granules in TCE co-metabolic removal.

  15. Oxidative Degradation of Phenol containing Wastewater using Fenton Reagent, Permanganate and Ultraviolet Radiation

    International Nuclear Information System (INIS)

    Abd El-Rahman, N.M.; Talaat, H.A.; Sorour, M.H.

    1999-01-01

    Phenol containing wastewaters are generated by numerous industrial units including integrated steel mills, textile mills, plastic production, etc. The present work is targeted to explore the viable oxidation techniques for degradation of phenolic wastewater. Three modes of treatment have been adopted in this study, namely, sole oxidant mode using Fenton reagent or permanganate, UV-assisted oxidation and two consequent chemical oxidation steps. Results indicated the superiority of fenton reagent over KMnO 4 oxidation in the sole oxidant mode. On the other hand, UV-assisted KMnO 4 oxidation enables almost complete COD reduction. Dual chemical oxidation mode employing KMnO 4 oxidation followed by Fenton reagent is also an efficient oxidative degradation system

  16. Oxidation Degradation Study And Use Of Phenol And Amina Antioxidant Compounds In Natural Rubber Cyclical

    OpenAIRE

    Arofah Megasari Siregar; Eddyanto; Basuki Wirjosentono; Ameilia Zuliyanti Siregar

    2015-01-01

    The research was conducted research into the use of commercial antioxidants Irganox 1010 wingstay to inhibit the oxidative degradation of cyclic polymers of natural rubber and polypropylene nanocomposite with commercial montmorillonite PP MMT-Clay. Proces mixing nanocomposit PPMMT using commercial compatibiliser PP-g-MA PB3200 made in an internal mixer at a temperature of 180 C for 10 minutes and 65 rpm rotor speed. Hyndered phenol antioxidant effectiveness was analyzed using Fourier Transfo...

  17. Degradation of 4-Chloro phenol by gamma radiation of 137Cs and X-rays

    International Nuclear Information System (INIS)

    Gonzalez J, J. C.; Jimenez B, J.; Cejudo A, J.

    2010-01-01

    This paper presents results of radiolytic degradation of 4-chloro phenol in the presence of TiO 2 , Al 2 O 3 and SiO 2 , using different radiation sources than 60 Co, which is so common in this type of experiment. The radiation sources used were X-rays with energy of 100 keV and radiation from 137 Cs (662 keV). After irradiation with a dose of 50 c Gy X-ray and TiO 2 obtained a degradation of about 5%, no degradation was obtained with 137 Cs source and other oxides. This may be due to the fact that X-rays have a linear energy transfer greater value, and in the case of TiO 2 present a crystalline structure, whereas the other two oxides are amorphous. Both characteristics result in better formation of a reactive species that allows the degradation of the compound. (Author)

  18. Identification of genes and pathways related to phenol degradation in metagenomic libraries from petroleum refinery wastewater.

    Directory of Open Access Journals (Sweden)

    Cynthia C Silva

    Full Text Available Two fosmid libraries, totaling 13,200 clones, were obtained from bioreactor sludge of petroleum refinery wastewater treatment system. The library screening based on PCR and biological activity assays revealed more than 400 positive clones for phenol degradation. From these, 100 clones were randomly selected for pyrosequencing in order to evaluate the genetic potential of the microorganisms present in wastewater treatment plant for biodegradation, focusing mainly on novel genes and pathways of phenol and aromatic compound degradation. The sequence analysis of selected clones yielded 129,635 reads at an estimated 17-fold coverage. The phylogenetic analysis showed Burkholderiales and Rhodocyclales as the most abundant orders among the selected fosmid clones. The MG-RAST analysis revealed a broad metabolic profile with important functions for wastewater treatment, including metabolism of aromatic compounds, nitrogen, sulphur and phosphorus. The predicted 2,276 proteins included phenol hydroxylases and cathecol 2,3- dioxygenases, involved in the catabolism of aromatic compounds, such as phenol, byphenol, benzoate and phenylpropanoid. The sequencing of one fosmid insert of 33 kb unraveled the gene that permitted the host, Escherichia coli EPI300, to grow in the presence of aromatic compounds. Additionally, the comparison of the whole fosmid sequence against bacterial genomes deposited in GenBank showed that about 90% of sequence showed no identity to known sequences of Proteobacteria deposited in the NCBI database. This study surveyed the functional potential of fosmid clones for aromatic compound degradation and contributed to our knowledge of the biodegradative capacity and pathways of microbial assemblages present in refinery wastewater treatment system.

  19. Degradation behavior of carbon nanotubes/phenol-furfuryl alcohol multifunctional composites with aerospace application

    Science.gov (United States)

    Conejo, L. S.; Costa, M. L.; Oishi, S. S.; Botelho, E. C.

    2017-10-01

    Lightweight and highly conductive composite associated with good impact and tribological properties could be used in the aerospace industry to replace metal for an aircraft skin and still provide effective shielding against electromagnetic interference (EMI). Also, phenol-furfuryl alcohol resins (PFA) are excellent candidates to replace existing thermoset matrices used for obtaining glassy carbon, both in its pure form and reinforced with nanoscale structures. The synthesis of PFA allow obtaining a resin with better properties than that showed by conventional phenolic resins and with synthesis and cure processes more controlled than observed for the furfuryl alcohol resin. This work has as main purpose the synthesis and thermal characterization of PFA resin and its nanostructured composites with different concentrations of carbon nanotubes (0, 0.1, 0.5 and 1.0 wt%). PFA resin was synthesized with 1:2:1 molar ratio of phenol/formaldehyde/furfuryl alcohol, according to the more appropriate condition obtained previously. The specimens were evaluated by thermogravimetry (TGA) to knowledge of the temperature of thermal degradation, either by actual analyses as simulated by simulation heating rate conversion software (known as Highway Simulation). The introduction of CNT in PFA sample does not affect its thermal stability. The values of residual weight found for samples with CNT additions are close to the values of the phenolic resin in the literature (about 60% residual weight).

  20. Microbial degradation of phenol in high-salinity solutions in suspensions and hollow fiber membrane contactors.

    Science.gov (United States)

    Juang, Ruey-Shin; Wu, Cheng-Ying

    2007-01-01

    A microporous polypropylene (PP) hollow fiber membrane contactor was used as a bioreactor to degrade phenol in aqueous solutions by Pseudomonas putida BCRC 14365 at 30 degrees C. The fibers were pre-wetted by ethanol to make them more hydrophilic. The initial cell density was fixed at 0.025 gl(-1). The effects of added NaCl concentration (0-1.78 M) and pH (3-8) in substrate solution on the biodegradation were studied. The experimental results by suspended cells were discussed. It was shown that the cells in microporous hollow fibers were unable to tolerate substrate solution pH to a larger range than those in suspensions. The suspended cells grew well on 100 mg l(-1) of phenol only at NaCl concentrations below 0.44 M. However, the cells in microporous hollow fibers could completely degrade 500 mg l(-1) of phenol in solutions containing NaCl concentration up to 1.52 M, which was due to the enhanced tolerance limit to salinity effect by the membrane-attached biofilms and the sufficiently slow mass transfer of NaCl through the membrane pores.

  1. Oxidative degradation of phenols in sono-Fenton-like systems upon high-frequency ultrasound irradiation

    Science.gov (United States)

    Aseev, D. G.; Sizykh, M. R.; Batoeva, A. A.

    2017-12-01

    The kinetics of oxidative degradation of phenol and chlorophenols upon acoustic cavitation in the megahertz range (1.7 MHz) is studied experimentally in model systems, and the involvement of in situ generated reactive oxygen species (ROSs) is demonstrated. The phenols subjected to high frequency ultrasound (HFUS) are ranked in terms of their rate of conversion: 2,4,6-trichlorophenol > 2,4-dichlorophenol 2-chlorophenol > 4-chlorophenol phenol. Oxidative degradation upon HFUS irradiation is most efficient at low concentrations of pollutants, due to the low steady-state concentrations of the in situ generated ROSs. A dramatic increase is observed in the efficiency of oxidation in several sonochemical oxidative systems (HFUS in combination with other chemical oxidative factors). The system with added Fe2+ (a sono-Fenton system) derives its efficiency from hydrogen peroxide generated in situ as a result of the recombination of OH radicals. The S2O8 2-/Fe2+/HFUS system has a synergetic effect on substrate oxidation that is attributed to a radical chain mechanism. In terms of the oxidation rates, degrees of conversion, and specific energy efficiencies of 4-chlorophenol oxidation based on the amount of oxidized substance per unit of expended energy the considered sonochemical oxidative systems form the series HFUS < S2O8 2-/HFUS < S2O8 2-/Fe2+/HFUS.

  2. Degradation of phenol by Rhodococcus erythropolis UPV-1 immobilized on Biolite in a packed-bed reactor.

    Science.gov (United States)

    Begoña Prieto, M; Hidalgo, Aurelio; Serra, Juan L; Llama, María J

    2002-07-17

    A strain of Rhodococcus erythropolis has been isolated and identified by 16S rRNA sequencing. Cells acclimated to phenol can be adsorbed on the external surface of beads of the ceramic support Biolite where they grow forming a network of large filaments. Exponentially-growing cells were adsorbed faster than their stationary-phase counterparts. Immobilization resulted in a remarkable enhancement of the respiratory activity of cells and a shorter lag phase preceding the active phenol degradation. Under optimum operation conditions, the immobilized cells in a laboratory-scale column reactor packed with support beads were able to degrade completely phenol in defined mineral medium at a maximum rate of 18 kg phenol m(-3) per day. The performance of the bioreactor in long-term continuous operation was characterized by pumping defined mineral medium which contained different concentrations of phenol at different flow-rates. Once phenol biodegradation in defined mineral medium was well established, an industrial wastewater from a resin manufacturing company, which contained both phenol and formaldehyde, was tested. In this case, after wastewater conditioning (i.e. pH, nitrogen source and micronutrient amendments) the immobilized cells were able to remove completely formaldehyde and to partly biodegrade phenols at a rate of 1 kg phenol m(-3) per day.

  3. Resorcinol degradation by a Penicillium chrysogenum strain under osmotic stress: mono and binary substrate matrices with phenol.

    Science.gov (United States)

    Guedes, Sumaya Ferreira; Mendes, Benilde; Leitão, Ana Lúcia

    2011-04-01

    A phenol-degrading Penicillium chrysogenum strain previously isolated from a salt mine was able to grow at 1,000 mg l(-1) of resorcinol on solid medium. The aerobic degradation of resorcinol by P. chrysogenum CLONA2 was studied in batch cultures in minimal mineral medium with 58.5 g l(-1) of sodium chloride using resorcinol as the sole carbon source. The fungal strain showed the ability to degrade up to 250 mg l(-1) of resorcinol. Resorcinol and phenol efficiency degradation by P. chrysogenum CLONA2 was compared. This strain removes phenol faster than resorcinol. When phenol and resorcinol were in binary substrate matrices, phenol enhanced resorcinol degradation, and organic load decreased with respect to the mono substrate matrices. The acute toxicity of phenol and resorcinol, individually and in combination, to Artemia franciscana larvae has been verified before and after the bioremediation process with P. chrysogenum CLONA2. The remediation process was effective in mono and binary substrate systems.

  4. Kinetic study of adsorption and degradation of aniline, benzoic acid, phenol, and diuron in soil suspensions

    International Nuclear Information System (INIS)

    Dao, T.H.; Lavy, T.L.

    1987-01-01

    Laboratory studies were conducted to investigate the effects of low temperature and accelerated soil-solution contact on soil adsorption of labile organic chemicals. The authors measured the kinetics of adsorption and degradation of 14 C-aniline, 14 C-benzoic acid, 14 C-phenol, and 14 C-diuron in the solution phase at 3 and 22 0 C. In the initial stages of reactions, the adsorption of all four chemicals was instantaneous at both temperatures under accelerated soil and solution mixing. A steady state was observed after the onset of equilibrium for the adsorption reaction for all compounds within 10 to 30 min. Its length varied according to the expected order of susceptibility to microbial degradation, i.e., diuron > aniline > phenol ≥ benzoate. It was apparent that the steady-state period without or in combination with low temperature could be advantageously used to obtain adsorption measurements in microbially active systems. A mechanistic sorption-catalyzed degradation model was evaluated to uncouple mathematically these processes. The model described satisfactorily the disappearance of labile chemicals in soil suspensions. Numerical analysis allowed the concurrent determination of adsorption, desorption, and biodegradation rate coefficients

  5. Biosurfactant production by Pseudomonas fluorescens growing on molasses and its application in phenol degradation

    Science.gov (United States)

    Suryantia, Venty; Marliyana, Soerya Dewi; Wulandari, Astri

    2015-12-01

    A molasses based medium for the biosurfactant production by Pseudomonas fluorescens was developed, where the effect of pre-treated of molasses and medium composition were evaluated. Biosurfactant production was followed by measuring optical density (OD), surface tension and emulsifying index (E24) over 12 days of fermentation. The optimum condition for the biosurfactant production was obtained when a medium containing of 8 g/L nutrient broth, 5 g/L NaCl, 1 g/L NH4NO3 and 5% v/v pre-treated molasses with centrifugation was used as media with 3 days of fermentation. The biosurfactant was identified as a rhamnolipid type biosurfactant which had critical micelle concentration (CMC) value of 801 mg/L and was able to reduce the surface tension of the water from 80 mN/m to 51 mN/m. The biosurfactants had water in oil (w/o) emulsion type. Biosurfactant was able to emulsify various hydrocarbons, which were able to decrase the interfacial tension about 50-75% when benzyl chloride, anisaldehyde and palm oil were used as immiscible compounds. The biosurfactant exhibited the E24 value of about 50% and the stable emulsion was reached up to 30 days when lubricant was used as an immiscible compound. Up to 68% of phenol was degraded in the presence of biosurfactant within 15 days, whereas only 56% of phenol was degraded in the absence of biosurfactant. Overall, the results exhibited that molasses are recommended for the rhamnolipids production which possessed good surface-active properties and had potential application in the enhancement of phenol degradation.

  6. Immobilization of Bacillus sp. in mesoporous activated carbon for degradation of sulphonated phenolic compound in wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Sekaran, G., E-mail: ganesansekaran@gmail.com [Environmental Technology Division, Council of Scientific and Industrial Research (CSIR), Central Leather Research Institute (CLRI), Adyar, Chennai-600 020 (India); Karthikeyan, S. [Environmental Technology Division, Council of Scientific and Industrial Research (CSIR), Central Leather Research Institute (CLRI), Adyar, Chennai-600 020 (India); Gupta, V.K. [Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee-247 667 (India); Department of Chemistry, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Boopathy, R.; Maharaja, P. [Environmental Technology Division, Council of Scientific and Industrial Research (CSIR), Central Leather Research Institute (CLRI), Adyar, Chennai-600 020 (India)

    2013-03-01

    Xenobiotic compounds are used in considerable quantities in leather industries besides natural organic and inorganic compounds. These compounds resist biological degradation and thus they remain in the treated wastewater in the unaltered molecular configurations. Immobilization of organisms in carrier matrices protects them from shock load application and from the toxicity of chemicals in bulk liquid phase. Mesoporous activated carbon (MAC) has been considered in the present study as the carrier matrix for the immobilization of Bacillus sp. isolated from Effluent Treatment Plant (ETP) employed for the treatment of wastewater containing sulphonated phenolic (SP) compounds. Temperature, pH, concentration, particle size and mass of MAC were observed to influence the immobilization behavior of Bacillus sp. The percentage immobilization of Bacillus sp. was the maximum at pH 7.0, temperature 20 Degree-Sign C and at particle size 300 {mu}m. Enthalpy, free energy and entropy of immobilization were - 46.9 kJ mol{sup -1}, - 1.19 kJ mol{sup -1} and - 161.36 J K{sup -1} mol{sup -1} respectively at pH 7.0, temperature 20 Degree-Sign C and particle size 300 {mu}m. Higher values of {Delta}H{sup 0} indicate the firm bonding of the Bacillus sp. in MAC. Degradation of aqueous sulphonated phenolic compound by Bacillus sp. immobilized in MAC followed pseudo first order rate kinetics with rate constant 1.12 Multiplication-Sign 10{sup -2} min{sup -1}. Highlights: Black-Right-Pointing-Pointer Degradation on phenolic syntan using immobilized activated carbon as catalyst. Black-Right-Pointing-Pointer Bacillus sp. immobilized cell reactor removed all refractory organic loads. Black-Right-Pointing-Pointer The removal mechanism is due to co-metabolism between carbon and organisms. Black-Right-Pointing-Pointer The organics are completely metabolized rather than adsorption.

  7. LOGICAL AND EXPERIMENTAL DESIGN FOR PHENOL DEGRADATION USING IMMOBILIZED ACINETOBACTER SP. CULTURE

    Directory of Open Access Journals (Sweden)

    Amro Abd Al Fattah Amara

    2010-05-01

    Full Text Available Phenol degradation processes were conducted through a series of enzymatic reactions effects and is affect by different components of the microbial metabolic flux. Using different optimization strategies like mutagenesis could lead to a successful optimization but also lead to lost of some important microbial features or to release a new virulence or unexpected characters. Plackett-Burman closes much gab between optimization, safety, time, cost, Man/hr, the complexity of the metabolic flux etc. Using Plackett-Burman experimental design lead to map the points affect in the optimization process by well understanding their request from nutrient and the best environmental condition required. In this study nine variables include pH (X1, oC (X2, glucose (X3, yeast extract (X4, meat extract (X5, NH4NO3 (X6, K-salt (X7, Mg-salt (X8 and trace element (X9 are optimized during phenol degradation by Acinetobacter sp., using Plackett-Burman design method. Plackett-Burman included 16 experiments, each was used in two levels, [-1] low and high [+1]. According to Blackett-Burman design experiments the maximum degradation rate was 31.25 mg/l/h. Logical and statistical analysis of the data lead to select pH, Temperature and Meat extract as three factors affecting on phenol degradation rate. These three variables have been used in Box-Behnken experimental design for further optimization. Meat extract, which is not statistically recommended for optimization has been used while it can substitute trace element, which is statistically significant. Glucose, which is statistically significant, did not included while it has a negative effect and gave the best result at 0 g/l amount. Glucose has been completely omitted from the media.  pH, temperature and meat extract were used in fifteen experiments each was used in three levels, –1, 0, and +1 according to Box-Behnken design. Microsoft Excel 2002 solver tool was used to optimize the model created from Box-Behnken. The

  8. Analysis of catRABC operon for catechol degradation from phenol-degrading Rhodococcus erythropolis

    Czech Academy of Sciences Publication Activity Database

    Veselý, Martin; Knoppová, Monika; Nešvera, Jan; Pátek, Miroslav

    2007-01-01

    Roč. 76, - (2007), s. 159-168 ISSN 0175-7598 R&D Projects: GA ČR GA526/04/0542 Institutional research plan: CEZ:AV0Z50200510 Keywords : rhodococcus erythropolis * catrabc operon * catechol degradation Subject RIV: EE - Microbiology, Virology Impact factor: 2.475, year: 2007

  9. Nitrogen-sensitized dual phase titanate/titania for visible-light driven phenol degradation

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Yu Hua; Subramaniam, Vishnu P.; Gong, Dangguo; Tang, Yuxin [School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Highfield, James, E-mail: James_Highfield@ices.a-star.edu.sg [Institute of Chemical and Engineering Sciences 1 Pesek Road, Jurong Island, Singapore 627833 (Singapore); Pehkonen, Simo O. [Chemical Engineering Program, Masdar Institute of Science and Technology, PO Box 54224, Abu Dhabi (United Arab Emirates); Pichat, Pierre [Photocatalyse et Environnement, CNRS/Ecole Centrale de Lyon (STMS), 69134 Ecully Cedex (France); Schreyer, Martin K. [Institute of Chemical and Engineering Sciences 1 Pesek Road, Jurong Island, Singapore 627833 (Singapore); Chen, Zhong, E-mail: aszchen@ntu.edu.sg [School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore)

    2012-12-15

    A dual-phase material (DP-160) comprising hydrated titanate (H{sub 2}Ti{sub 3}O{sub 7}{center_dot}xH{sub 2}O) and anatase (TiO{sub 2}) was synthesized in a low-temperature one-pot process in the presence of triethylamine (TEA) as the N-source. The unique structure exhibits strong visible light absorption. The chromophore is linked to Ti-N bonds derived from both surface sensitization and sub-surface (bulk) doping. From transmission electron microscope (TEM) and textural studies by N{sub 2} physisorption, the composite exists as mesoporous particles with a grain size of {approx}20 nm and mean pore diameter of 3.5 nm, responsible for the high surface area ({approx}180 m{sup 2}/g). DP-160 demonstrated photocatalytic activity in the degradation of phenol under visible light ({lambda}>420 nm). The activity of the composite was further enhanced by a small addition (0.001 M) of H{sub 2}O{sub 2}, which also gave rise to some visible light activity in the control samples. This effect is believed to be associated with the surface peroxo-titanate complex. GC-MS analyses showed that the intermediate products of phenol degradation induced by visible light irradiation of DP-160 did not differ from those obtained by UV (band-gap) irradiation of TiO{sub 2}. The overall performance of the composite is attributed to efficient excitation via inter-band states (due to N-doping), surface sensitization, improved adsorptive properties of aromatic compounds due to the N-carbonaceous overlayer, and the presence of heterojunctions that are known to promote directional charge transfer in other mixed-phase titanias like Degussa P25. - graphical abstract: Nitrogen-sensitized dual phase titanate/titania photocatalyst showing extended visible light absorption and efficient photocatalytic degradation of phenol. Highlights: Black-Right-Pointing-Pointer Low temperature one-pot synthesis of visible light active dual phase photocatalyst. Black-Right-Pointing-Pointer The dual phase consists of

  10. Phenol degradation on Pr6O11 surface under UV-A light. Synergistic photocatalysis by semiconductors

    International Nuclear Information System (INIS)

    Karunakaran, C.; Dhanalakshmi, R.

    2009-01-01

    Phenol degrades on the surface of Pr 6 O 11 , an insulator, under UV-A light and the degradation rate increases linearly with phenol concentration and photon flux but decreases linearly with pH. The degradation efficiency is higher with UV-C light than with UV-A light. While TiO 2 , Fe 2 O 3 , CuO, ZnO, ZnS, Nb 2 O 5 and CdO particles individually photocatalyze the degradation each semiconductor exhibits synergistic effect, an enhanced photodegradation, when present along with Pr 6 O 11 suggesting hole-transfer from illuminated semiconductors to phenol adsorbed on Pr 6 O 11 during collision

  11. Roles of manganese oxides in degradation of phenol under UV-Vis irradiation: adsorption, oxidation, and photocatalysis.

    Science.gov (United States)

    Zhang, Qin; Cheng, Xiaodi; Zheng, Chen; Feng, Xionghan; Qiu, Guohong; Tan, Wenfeng; Liu, Fan

    2011-01-01

    Manganese oxides are known as one type of semiconductors, but their photocatalysis characteristics have not been deeply explored. In this study, photocatalytic degradation of phenol using several synthesized manganese oxides, i.e, acidic birnessite (BIR-H), alkaline birnessite (BIR-OH), cryptomelane (CRY) and todorokite (TOD), were comparatively investigated. To elucidate phenol degradation mechanisms, X-ray diffraction (XRD), ICP-AES (inductively coupled plasma-atomic emission spectroscopy), TEM (transmission electronic microscope), N2 physisorption at 77 K and UV-visible diffuse reflectance spectroscopy (UV-Vis DRS) were employed to characterize the structural, compositional, morphological, specific surface area and optical absorption properties of the manganese oxides. After 12 hr of UV-Vis irradiation, the total organic carbon (TOC) removal rate reached 62.1%, 43.1%, 25.4%, and 22.5% for cryptomelane, acidic birnessite, todorokite and alkaline birnessite, respectively. Compared to the reactions in the dark condition, UV-Vis exposure improved the TOC removal rates by 55.8%, 31.9%, 23.4% and 17.9%. This suggests a weak ability of manganese oxides to degrade phenol in the dark condition, while UV-Vis light irradiation could significantly enhance phenol degradation. The manganese minerals exhibited photocatalytic activities in the order of: CRY > BIR-H > TOD > BIR-OH. There may be three possible mechanisms for photochemical degradation: (1) direct photolysis of phenol; (2) direct oxidation of phenol by manganese oxides; (3) photocatalytic oxidation of phenol by manganese oxides. Photocatalytic oxidation of phenol appeared to be the dominant mechanism.

  12. Tunable Degradation Rate and Favorable Bioactivity of Porous Calcium Sulfate Scaffolds by Introducing Nano-Hydroxyapatite

    Directory of Open Access Journals (Sweden)

    Jianhua Zhou

    2016-12-01

    Full Text Available The bone scaffolds should possess suitable physicochemical properties and osteogenic activities. In this study, porous calcium sulfate (CaSO4 scaffolds were fabricated successfully via selected laser sintering (SLS. Nano-hydroxyapatite (nHAp, a bioactive material with a low degradation rate, was introduced into CaSO4 scaffolds to overcome the overquick absorption. The results demonstrated that nHAp could not only control the degradation rate of scaffolds by adjusting their content, but also improve the pH environment by alleviating the acidification progress during the degradation of CaSO4 scaffolds. Moreover, the improved scaffolds were covered completely with the apatite spherulites in simulated body fluid (SBF, showing their favorable bioactivity. In addition, the compression strength and fracture toughness were distinctly enhanced, which could be ascribed to large specific area of nHAp and the corresponding stress transfer.

  13. Physiological changes of Candida tropicalis population degrading phenol in fed batch reactor

    Directory of Open Access Journals (Sweden)

    Eliska Komarkova

    2003-12-01

    Full Text Available Candida tropicalis can use phenol as the sole carbon and energy source. Experiments regarding phenol degradations from the water phase were carried out. The fermentor was operated as a fed-batch system with oxistat control. Under conditions of nutrient limitation and an excess of oxygen the respiration activity of cells was suppressed and some color metabolites (black-brown started to be formed. An accumulation of these products inhibited the cell growth under aerobic conditions. Another impact was a decrease of the phenol hydroxylase activity as the key enzyme of the phenol degradation pathway at the end of the cell respiration activity. This decrease is linked with the above mentioned product inhibition. The cell death studied by fluorescent probe proceeded very slowly after the loss of the respiration activity. The starvation stress induced an increase of the endogenous respiration rate at the expense of phenol oxidation.Candida tropicalis pode utilizar fenol como única fonte de carbono e de energia. O fermentador foi operado em um sistema ''batelada-alimentada'' e controle oxidativo. Em condições limitantes de nutrientes e excesso de oxigênio a atividade respiratória das células foi suprimida e o calor do metabolismo pode ser formado. Uma acumulação desses produtos inibiu o crescimento das células em condições aeróbicas. Outro impacto foi um decréscimo da atividade fenol hidroxilase como enzima chave da degradação do fenol no final da atividade respirométrica. Essa redução está relacionada com os fatos acima mencionados. A morte da célula estudada por sonda de fluorescência ocorreu lentamente após a perda da atividade respiratória. O ''stress'' celular induziu um aumento na taxa de respiração endógena devido à oxidação fenólica.

  14. Preparation and Electrocatalytic Performance of Bi-Modified Quartz Column Particle Electrode for Phenol Degradation

    Directory of Open Access Journals (Sweden)

    Jiguo Huang

    2015-01-01

    Full Text Available Bismuth oxide (Bi2O3 and its composites have good electrocatalytic performance. Quartz column is a good kind of catalyst carrier with the characteristics of high mechanical strength and good stability. A novel Bi-modified quartz column particle electrode (BQP was prepared by the dipping-calcination method. The characterization results revealed that Bi2O3 was successfully loaded on quartz column. The optimum preparation condition was calcining at 550°C for 4 h. Electrocatalytic performance was evaluated by the degradation of phenol and the results indicated that the triclinic phase of Bi2O3 showed the best electrocatalytic property. Besides, when the dosage concentration of the particle electrode was 125 g/L and the electrolytic voltage was 12 V, the degradation rate of phenol (200 mg/L reached the highest (94.25%, compared with 70.00% of that in two-dimensional (2D system. In addition, the removal rate of chemical oxygen demand (COD was 75.50%, compared with 53.30% of that in 2D system. The reusability and regeneration of BQP were investigated and the results were good. Mechanism of enhanced electrochemical oxidation by BQP was evaluated by the capture of hydroxyl radical.

  15. Degradation of phenolics, nitrogen-heterocyclics and polynuclear aromatic hydrocarbons in a rotating biological contactor.

    Science.gov (United States)

    Jeswani, Hansa; Mukherji, Suparna

    2012-05-01

    The degradation of phenolics, heterocyclics and polynuclear aromatic hydrocarbons (PAHs) in a synthetic biomass gasifier wastewater with average COD of 1388 mg/L was studied in a three stage rotating biological contactor (RBC) using the pyrene degrader, Exiguobacterium aurantiacum and activated sludge consortia (1:3 v/v). As the organic loading rate (OLR) was varied from 3.3 to 14 g/m(2)/d, the COD removal ranged from 63.3% to 92.6%. Complete removal of all the constituents was observed at the lowest OLR of 3.3g/m(2)/d. At 24h hydraulic retention time (HRT) and OLR of 6.6g/m(2)/d complete removal of pyridine, quinoline and benzene and 85-96% removal of phenol, naphthalene, phenanthrene, fluoranthene and pyrene was observed. E. aurantiacum was found to be the dominant bacteria in the biofilm. Clark's model provided good fits to data for all the three stages of the RBC. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. 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

    2017-05-01

    In this study, solid acid amorphous Fe 3 O 4 /SiO 2 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 Na 2 S 2 O 8 as sulfur source. The surface morphology and phase composition were characterized by SEM, EDS, XRD and XPS analyses. NH 3 -TPD was used to evaluate surface acidity of PEO coating. The results indicated that sulfur decorated amorphous Fe 3 O 4 /SiO 2 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 Na 2 S 2 O 8 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 Na 2 S 2 O 8 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. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Biochemical, transcriptional and translational evidences of the phenol-meta-degradation pathway by the hyperthermophilic Sulfolobus solfataricus 98/2.

    Directory of Open Access Journals (Sweden)

    Alexia Comte

    Full Text Available Phenol is a widespread pollutant and a model molecule to study the biodegradation of monoaromatic compounds. After a first oxidation step leading to catechol in mesophilic and thermophilic microorganisms, two main routes have been identified depending on the cleavage of the aromatic ring: ortho involving a catechol 1,2 dioxygenase (C12D and meta involving a catechol 2,3 dioxygenase (C23D. Our work aimed at elucidating the phenol-degradation pathway in the hyperthermophilic archaea Sulfolobus solfataricus 98/2. For this purpose, the strain was cultivated in a fermentor under different substrate and oxygenation conditions. Indeed, reducing dissolved-oxygen concentration allowed slowing down phenol catabolism (specific growth and phenol-consumption rates dropped 55% and 39%, respectively and thus, evidencing intermediate accumulations in the broth. HPLC/Diode Array Detector and LC-MS analyses on culture samples at low dissolved-oxygen concentration (DOC  =  0.06 mg x L(-1 suggested, apart for catechol, the presence of 2-hydroxymuconic acid, 4-oxalocrotonate and 4-hydroxy-2-oxovalerate, three intermediates of the meta route. RT-PCR analysis on oxygenase-coding genes of S. solfataricus 98/2 showed that the gene coding for the C23D was expressed only on phenol. In 2D-DIGE/MALDI-TOF analysis, the C23D was found and identified only on phenol. This set of results allowed us concluding that S. solfataricus 98/2 degrade phenol through the meta route.

  18. Degradation of 4-Chloro phenol by gamma radiation of {sup 137}Cs and X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez J, J. C. [Instituto Tecnologico de Toluca, Av. Tecnologico s/n, Ex-Rancho La Virgen, 52140 Metepec, Estado de Mexico (Mexico); Jimenez B, J.; Cejudo A, J., E-mail: jaime.jimenez@inin.gob.m [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2010-07-01

    This paper presents results of radiolytic degradation of 4-chloro phenol in the presence of TiO{sub 2}, Al{sub 2}O{sub 3} and SiO{sub 2}, using different radiation sources than {sup 60}Co, which is so common in this type of experiment. The radiation sources used were X-rays with energy of 100 keV and radiation from {sup 137}Cs (662 keV). After irradiation with a dose of 50 c Gy X-ray and TiO{sub 2} obtained a degradation of about 5%, no degradation was obtained with {sup 137}Cs source and other oxides. This may be due to the fact that X-rays have a linear energy transfer greater value, and in the case of TiO{sub 2} present a crystalline structure, whereas the other two oxides are amorphous. Both characteristics result in better formation of a reactive species that allows the degradation of the compound. (Author)

  19. Fast gradient HPLC/MS separation of phenolics in green tea to monitor their degradation.

    Science.gov (United States)

    Šilarová, Petra; Česlová, Lenka; Meloun, Milan

    2017-12-15

    The degradation of catechins and other phenolics in green tea infusions were monitored using fast HPLC/MS separation. The final separation was performed within 2.5min using Ascentis Express C18 column (50mm×2.1mm i.d.) packed with 2μm porous shell particles. Degradation was studied in relation to the temperature of water (70, 80, 90°C) and the standing time of the infusion (up to 6h). Along with chromatographic separation, the antioxidant properties of the infusions were monitored using two spectrophotometric methods. During staying of green tea infusion, the degradation of some catechins probably to gallic acid was observed. Finally, the influence of tea bag storage on antioxidant properties of green tea was evaluated. Rapid degradation of antioxidants after 3weeks was observed. The principal component analysis, factor analysis and discriminant analysis were used for the statistical evaluation of obtained experimental data. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Olive Mill Wastewater (OMW) Phenol Compounds Degradation by Means of a Visible Light Activated Titanium Dioxide-Based Photocatalyst

    Science.gov (United States)

    Cuomo, Francesca; Venditti, Francesco; Cinelli, Giuseppe; Ceglie, Andrea; Lopez, Francesco

    2016-09-01

    The use of titanium dioxide as heterogeneous photocatalyst is drawing considerable attention for water and air purification and remediation. Recently, TiO2 particles have been modified in order to make this material attractive for industrial and environmental remediation usage. In the present study, phenolic compounds of olive mill wastewater (OMW) were degraded in the presence of glucose-doped titanium particles (CDT) through a photocatalysis process activated by visible light. The photocatalyst effectiveness towards the polluted wastewater from olive oil industry was tested on systems having different initial concentrations of phenols and in the presence of different amounts of CDT. For kinetic analysis the role of Ti/TPh ratio (amount of catalyst/amount of total phenols) was investigated. The rate constant (k2) and the amounts of species adsorbed on adsorbent at equilibrium (qe) of each reaction were calculated by fitting kinetics data to a second-order kinetic adsorption model. The results collected at different Ti/TPh ratios showed that the amount of phenols that can be removed from the water solution linearly increases with the Ti/TPh ratio till a maximum value (optimal ratio) at which no further degradation of phenolic compounds was obtainable. Such kind of parameter allows to identify the optimal value of catalyst and the initial substrate concentration for a high level of degradation. The results showed in this study can have an important impact for an applicative point of view.

  1. Phenolic acid degradation potential and growth behavior of lactic acid bacteria in sunflower substrates.

    Science.gov (United States)

    Fritsch, Caroline; Heinrich, Veronika; Vogel, Rudi F; Toelstede, Simone

    2016-08-01

    Sunflower flour provides a high content of protein with a well-balanced amino acid composition and is therefore regarded as an attractive source for protein. The use for human nutrition is hindered by phenolic compounds, mainly chlorogenic acid, which can lead under specific circumstances to undesirable discolorations. In this study, growth behavior and degradation ability of chlorogenic acid of four lactic acid bacteria were explored. Data suggested that significant higher fermentation performances on sunflower flour as compared to sunflower protein concentrate were reached by Lactobacillus plantarum, Pediococcus pentosaceus, Lactobacillus gasseri and Bifidobacterium animalis subsp. lactis. In fermentation with the latter two strains reduced amounts of chlorogenic acid were observed in sunflower flour (-11.4% and -19.8%, respectively), which were more pronounced in the protein concentrate (-50.7% and -95.6%, respectively). High tolerances against chlorogenic acid and the cleavage product quinic acid with a minimum inhibitory concentration (MIC) of ≥20.48 mg/ml after 48 h were recorded for all strains except Bifidobacterium animalis subsp. lactis, which was more sensitive. The second cleavage compound, caffeic acid revealed a higher antimicrobial potential with MIC values of 0.64-5.12 mg/ml. In this proof of concept study, degradation versus inhibitory effect suggest the existence of basic mechanisms of interaction between phenolic acids in sunflower and lactic acid bacteria and a feasible way to reduce the chlorogenic acid content, which may help to avoid undesired color changes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Microbial degradation of plant leachate alters lignin phenols and trihalomethane precursors

    Science.gov (United States)

    Pellerin, Brian A.; Hernes, Peter J.; Saraceno, John Franco; Spencer, Robert G.M.; Bergamaschi, Brian A.

    2010-01-01

    Although the importance of vascular plant-derived dissolved organic carbon (DOC) in freshwater systems has been studied, the role of leached DOC as precursors of disinfection byproducts (DBPs) during drinking water treatment is not well known. Here we measured the propensity of leachates from four crops and four aquatic macrophytes to form trihalomethanes (THMs)—a regulated class of DBPs—before and after 21 d of microbial degradation. We also measured lignin phenol content and specific UV absorbance (SUVA254) to test the assumption that aromatic compounds from vascular plants are resistant to microbial degradation and readily form DBPs. Leaching solubilized 9 to 26% of total plant carbon, which formed 1.93 to 6.72 mmol THM mol C-1 However, leachate DOC concentrations decreased by 85 to 92% over the 21-d incubation, with a concomitant decrease of 67 to 92% in total THM formation potential. Carbon-normalized THM yields in the residual DOC pool increased by 2.5 times on average, consistent with the preferential uptake of nonprecursor material. Lignin phenol concentrations decreased by 64 to 96% over 21 d, but a lack of correlation between lignin content and THM yields or SUVA254 suggested that lignin-derived compounds are not the source of increased THM precursor yields in the residual DOC pool. Our results indicate that microbial carbon utilization alters THM precursors in ecosystems with direct plant leaching, but more work is needed to identify the specific dissolved organic matter components with a greater propensity to form DBPs and affect watershed management, drinking water quality, and human health.

  3. Phenology, TPC and size-fractioning phenolics variability in temperate Sargassaceae (Phaeophyceae, Fucales) from Western Brittany: native versus introduced species.

    Science.gov (United States)

    Le Lann, K; Connan, S; Stiger-Pouvreau, V

    2012-09-01

    The phenology of the introduced Sargassum muticum and two native species Bifurcaria bifurcata and Cystoseira baccata were monitored during eighteen months at two sites in Brittany. Density and length varied seasonally only in Sargassum. Larger individuals of Sargassum were observed in summer whereas in Cystoseira, they appeared almost in autumn. Peaks in maturity were delayed: in summer for Sargassum and in winter for Cystoseira and Bifurcaria. Phenolic contents increased before their respective reproductive period as a chemical defence. Moreover, size composition varied with site and season depending on species. In Sargassum, the quantity of small compounds decreased in summer together with an increase of 2000/5000 Da compounds. In Bifurcaria 2000/5000 Da compounds increased in summer (photoprotection) while in Cystoseira it increased in winter (protection for reproduction). Sargassum presented then a phenological plasticity not observed in native species. Moreover the three species possessed different chemical strategies to succeed in partitioning their vital space. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Degradation of phenol and Cr (VI) wastewater with contact glow discharge electrolysis method and the addition of Fe2+

    Science.gov (United States)

    Kurniawan, Raden Ridzki Aditya; Saksono, Nelson

    2017-11-01

    Phenol and Cr (VI) are an organic waste and dangerous heavy metals which generated from a wide variety of industrial processes such as textiles, paints, dyes, and others. For that reason, we need effective waste treatment technologies, one of them is Contact Glow Discharge Electrolysis (CGDE). This method produce reactive species such as radical hidroxyl so as to be able to degradate phenol and Cr(VI) wastewater effectively. This research aims to obtain the effect of Fe 2+ and air bubbles in degradation of phenol and Cr (VI) waste simultaneously. Waste degradation is measured its absorbance with UV-Vis spectrophotometer. In the conditions of 600 Volt voltage, Na2SO4 0.02 M, anode depth of 1.5 cm, the addition of Fe2+ 40 ppm and the addition of air bubbles for 30 minutes was obtained a percentage degradation of phenol 99.47%, Cr (VI) 76.75% and specific energy of 344.473 kJ / mmol.

  5. Oxidation Degradation Study And Use Of Phenol And Amina Antioxidant Compounds In Natural Rubber Cyclical

    Directory of Open Access Journals (Sweden)

    Arofah Megasari Siregar

    2015-08-01

    Full Text Available The research was conducted research into the use of commercial antioxidants Irganox 1010 wingstay to inhibit the oxidative degradation of cyclic polymers of natural rubber and polypropylene nanocomposite with commercial montmorillonite PP MMT-Clay. Proces mixing nanocomposit PPMMT using commercial compatibiliser PP-g-MA PB3200 made in an internal mixer at a temperature of 180 C for 10 minutes and 65 rpm rotor speed. Hyndered phenol antioxidant effectiveness was analyzed using Fourier Transform Infra Red FTIR. Analysis of infrared is done by measuring the broad index absorption of the carbonyl group CO at a wavelength of 1700 cm-1 and a broad index uptake hydroxyl group at a wavelength of 3400 cm-1 before and after heated in an oven temperature of 125oC with variations in exposure time. The results indicate the use of antioxidant Irganox 1010 in nanocomposite PP MMT with a stabilizing factor of 5.5. Further commercial antioxidants will be used to restrain the rate of oxidation degradation of the natural rubber products cyclical CNR.

  6. HETEROGENEOUS PHOTOCATALYTIC DEGRADATION OF PHENOL IN AQUEOUS SUSPENSION OF PERIWINKLE SHELL ASH CATALYST IN THE PRESENCE OF UV FROM SUNLIGHT

    Directory of Open Access Journals (Sweden)

    OSARUMWENSE, J. O.

    2015-12-01

    Full Text Available The batch photocatalytic degradation of phenol in aqueous solution wasinvestigated using periwinkle shell ash (PSA as photocatalyst. Chemical characterisation of the PSA revealed that the major oxides present were calcium oxide (CaO, silica (SiO2 and aluminium oxide (Al2O3 which accounted for 41.3, 33.2 and 9.2% of the weight of PSA characterised. The major elements in PSA were iron (19.2% and zinc (16.5%. FTIR results revealed absorption peaks of 3626.59 cm−1, 1797.58 cm−1, 1561.43 cm−1 and 1374.34 cm−1 in the infrared spectrum of PSA corresponding to O–H, C= O, C= C and C–H bonds respectively. Increasing the initial phenol concentration resulted in a decrease in the degradation efficiency of PSA. Lower catalyst loadings favoured the degradation process. Maximum degradation efficiency was obtained when the initial phenol concentration and catalyst loading were set as 50 g/L and 5 g/L respectively. The kinetics of the degradation process was well described by the pseudo first order equation while the diffusion mechanism was well represented by the intra particle diffusion model (R2>0.90. The adsorption equilibrium data fitted well to the Langmuir isotherm equation with an R2 value of 0.997.

  7. Application of a Novel Semiconductor Catalyst, CT, in Degradation of Aromatic Pollutants in Wastewater: Phenol and Catechol

    Directory of Open Access Journals (Sweden)

    Xiao Chen

    2014-01-01

    Full Text Available Water-soluble phenol and phenolic compounds were generally removed via advanced oxidation processes. A novel semiconductor catalyst, CT, was the first-time employed in the present study to degrade phenol and catechol. The phenolic compounds (initial concentration of 88 mg L−1 were completely mineralized by the CT catalytic nanoparticles (1% within 15 days, under acidic condition and with the presence of mild UV radiation (15 w, the emitted wavelength is 254 nm and the light intensity <26 μw/cm2. Under the same reaction condition, 1% TiO2 (mixture of rutile and anatase, nanopowder, <100 nm and H2O2 had lower removal efficiency (phenol: <42%; catechol: <60%, whereas the control (without addition of catalysts/H2O2 only showed <12% removal. The processes of phenol/catechol removal by CT followed pseudo-zero-order kinetics. The aromatic structures absorbed the UV energy and passed to an excited state, which the CT worked on. The pollutants were adsorbed on the CT’s surface and oxidized via charge-transfer and hydroxyl radical generation by CT. Given low initial concentrations, a circumstance encountered in wastewater polishing, the current set-up should be an efficient and less energy- and chemical-consumptive treatment method.

  8. Synergic mechanism of adsorption and metal-free catalysis for phenol degradation by N-doped graphene aerogel.

    Science.gov (United States)

    Ren, Xiaohua; Guo, Huanhuan; Feng, Jinkui; Si, Pengchao; Zhang, Lin; Ci, Lijie

    2018-01-01

    3D porous N-doped reduced graphene oxide (N-rGO) aerogels were synthesized by a hydrothermal reduction of graphene oxide (GO) with urea and following freeze-drying process. N-rGO aerogels have a high BET surface of 499.70 m 2 /g and a high N doping content (5.93-7.46 at%) including three kinds of N (graphitic, pyridinic and pyrrolic). Their high catalytic performance for phenol oxidation in aqueous solution was investigated by catalytic activation of persulfate (PS). We have demonstrated that N-rGO aerogels are promising metal-free catalysts for phenol removal. Kinetics studies indicate that phenol degradation follows first-order reaction kinetics with the reaction rate constant of 0.16799 min -1 for N-rGO-A(1:30). Interestingly, the comparison of direct catalytic oxidation with adsorption-catalytic oxidation experiments indicates that adsorption plays an important role in the catalytic oxidation of phenol by decreasing the phenol degradation time. Spin density and adsorption modeling demonstrates that graphitic N in N-rGO plays the most important role for the catalytic performance by inducing high positive charge densities to adjacent carbon atoms and facilitating phenol adsorption on these carbon sites. Furthermore, the activation mechanism of persulfate (PS) on N-rGO was first investigated by DFT method and PS can be activated to generate strongly oxidative radical (SO 4 · - ) by transferring electrons to N-rGO. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Ag nanoparticles loaded on porous graphitic carbon nitride with enhanced photocatalytic activity for degradation of phenol

    Science.gov (United States)

    Han, Zhenwei; Wang, Nan; Fan, Hai; Ai, Shiyun

    2017-03-01

    Highly efficient photocatalyst of visible-light-driven Ag nanoparticles loaded on porous graphitic carbon nitride (g-C3N4) was prepared by the reduction of Ag ions on porous g-C3N4. The obtained Ag/porous g-C3N4 composite products were characterized by X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), UV-vis diffuse reflection spectra (DRS), thermal gravimetric analysis (TGA). The results demonstrated that a homogeneous distribution of Ag NPs of 10 nm was attached onto the surface of the porous g-C3N4. The prepared Ag/porous g-C3N4 samples were applied for catalyzing the degradation of phenol in water under visible light irradiation. Porous g-C3N4 demonstrated an excellent support for the formation and dispersion of small uniform Ag NPs. When the weight percentage of Ag reaches 5%, the nanohybrid exhibits superior photocatalytic activities compared to bulk g-C3N4, porous g-C3N4, and 2% Ag/porous g-C3N4 hybrids. The enhanced photocatalytic performance is due to the synergic effect between Ag and porous g-C3N4, which suppressed the recombination of photogenerated electron-hole pairs.

  10. Microbial Degradation of Phenols and Aromatic Hydrocarbons in Creosote-contaminated Groundwater Under Nitrate-reducing Conditions

    DEFF Research Database (Denmark)

    Flyvbjerg, John; Arvin, Erik; Jensen, Bjørn K.

    1993-01-01

    of toluene, phenol, the cresols (o-, m- and p-cresol) and the dimethylphenols 2,4-DMP and 3,4-DMP at both 10° and 20°C. Benzene, the xylenes, napthalene, 2,3-DMP, 2,5-DMP, 2,6-DMP and 3,5-DMP were resistant to biodegradation during 7–12 months of incubation. It was demonstrated that the degradation...

  11. Fe(3+)- and Cu(2+)-reduction by phenol derivatives associated with Azure B degradation in Fenton-like reactions.

    Science.gov (United States)

    Aguiar, André; Ferraz, André

    2007-01-01

    Several phenol derivatives were evaluated regarding their capacities for Fe(3+) and Cu(2+) reduction. Selected compounds were assayed in Fenton-like reactions to degrade Azure B. 3,4-Dihydroxyphenylacetic, 2,5-dihydroxyterephtalic, gallic, chromotropic and 3-hydroxyanthranilic acids were the most efficient reducers of both metallic ions. The reaction system composed of 3-hydroxyanthranilic acid/Fe(3+)/H(2)O(2) was able to degrade Azure B at higher levels than the conventional Fenton reaction (87% and 75% of decolorization after 20min reaction, respectively). Gallic and syringic acids, catechol and vanillin induced Azure B degradations at lower levels as compared with conventional Fenton reaction. Azure B was not degraded in the presence of 10% (v/v) methanol or ethanol, which are OH radical scavengers, confirming the participation of this radical in the degradation reactions. Iron-containing reactions consumed substantially more H(2)O(2) than reactions containing copper. In iron-containing reactions, even the systems that caused a limited degradation of the dye consumed high concentrations of H(2)O(2). On the other hand, the reactions containing Fe(3+), H(2)O(2) and 3-hydroxyanthranilic acid or 3,4-dihydroxyphenylacetic acid were the most efficient on degradation of Azure B and also presented the highest H(2)O(2) consumption. These results indicate that H(2)O(2) consumption occurs even when the dye is not extensively degraded, suggesting that part of the generated OH radicals reacts with the own phenol derivative instead of Azure B.

  12. Extracellular laccase production and phenolic degradation by an olive mill wastewater isolate

    Directory of Open Access Journals (Sweden)

    R. Kumar

    2018-03-01

    Full Text Available Olive mill wastewater (OMWW presents a challenge to the control of effluents due to the presence of a high organic load, antimicrobial agents (monomeric-polymeric phenols, volatile acids, polyalcohols, and tannins, salinity and acidity. In this study, the production of extracellular laccase, monomeric or polymeric phenol, from an OMWW isolate based on its ability to biodegrade phenols and gallic acid as a model of phenolic compounds in OMWW was investigated. Phylogenetic analysis of the 16S RNA gene sequences identified the bacterial isolate (Acinetobacter REY as being closest to Acinetobacter pittii. This isolate exhibited a constitutive production of extracellular laccase with an activity of 1.5 and 1.3 U ml/L when supplemented with the inducers CuSO4 and CuSO4+phenols, respectively. Batch experiments containing minimal media supplemented with phenols or gallic acid as the sole carbon and energy source were performed in order to characterize their phenolic biodegradability. Acinetobacter REY was capable of biodegrading up to 200 mg/L of phenols and gallic acid both after 10 h and 72 h, respectively.

  13. Simultaneous bond degradation and bond formation during phenol-formaldehyde curing with wood

    Science.gov (United States)

    Daniel J. Yelle; John Ralph

    2016-01-01

    Bonding of wood using phenol–formaldehyde adhesive develops highly durable bonds. Phenol– formaldehyde is believed to form primary bonds with wood cell wall polymers (e.g., lignin). However, it is unclear how this adhesive interacts and bonds to lignin. Through wood solubilisation methodologies, earlywood and latewood bonded assemblies were characterized using two-...

  14. Microbial Degradation of Phenols and Aromatic Hydrocarbons in Creosote-contaminated Groundwater Under Nitrate-reducing Conditions

    DEFF Research Database (Denmark)

    Flyvbjerg, John; Arvin, Erik; Jensen, Bjørn K.

    1993-01-01

    Batch experiments were carried out to investigate the biodegradation of phenols and aromatic hydrocarbons under anaerobic, nitrate-reducing conditions in groundwater from a creosote-contaminated site at Fredensborg, Denmark. The bacteria in the creosote-contaminated groundwater degraded a mixture...... of toluene, phenol, the cresols (o-, m- and p-cresol) and the dimethylphenols 2,4-DMP and 3,4-DMP at both 10° and 20°C. Benzene, the xylenes, napthalene, 2,3-DMP, 2,5-DMP, 2,6-DMP and 3,5-DMP were resistant to biodegradation during 7–12 months of incubation. It was demonstrated that the degradation...... that in addition to the phenols are toluene other carbon sources present in the groundwater contributed to the consumption of nitrate. If the groundwater was incubated under anaerobic conditions without nitrate, sulphate-reducing conditions evolved after ∼ 1 month at 20°C and ∼2 months at 10°C. In the sulphate...

  15. Implementation of ozonation process in degradation of the phenols present in petrochemistry effluents; Aplicacao do processo de ozonizacao na degradacao de fenois presentes em efluentes petroquimicos

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Fernanda Batista de; Souza, Antonio Augusto Ulson de; Souza, Selene Maria Arruda Guelli Ulson de [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil)

    2008-07-01

    The water contamination by the petrochemical pollutants with high toxicity, such as phenols, is a subject of interest of several researchers. The ozone is an alternative for the effluents treatment, being effective in environmental decontamination, reducing the COD and degrading the phenols. The ozone stability depends on the water pH, the type and content of organic matter. This study aimed to investigate in the phenol ozonation, evaluating the phenol and COD removal at different pHs. Ozone as injected in 5 L of phenol solution of 50 mg L-1 at pH = 2, 7 and 10, from 1 to 25 minutes, and then was measured the quantity of COD and phenol. It was found that in acid pH the ozone has increased the stability, because 82.19% of the ozone that enters in the column remains in solution. The phenol degradation was faster in alkaline solution (pH=10), where in 15 minutes of treatment, 99.7% of phenol was consumed. The COD removal increased from 7.3% in 6 minutes to 87.8% in 30 minutes, but the COD removal increases more slowly than that of phenol which was 53, 8% in 6 min, increasing to 99.2% at 25 min for pH=7. (author)

  16. Potentialities of a Membrane Reactor with Laccase Grafted Membranes for the Enzymatic Degradation of Phenolic Compounds in Water

    Directory of Open Access Journals (Sweden)

    Vorleak Chea

    2014-10-01

    Full Text Available This paper describes the degradation of phenolic compounds by laccases from Trametes versicolor in an enzymatic membrane reactor (EMR. The enzymatic membranes were prepared by grafting laccase on a gelatine layer previously deposited onto α-alumina tubular membranes. The 2,6-dimethoxyphenol (DMP was selected  from among the three different phenolic compounds tested (guaiacol, 4-chlorophenol and DMP to study the performance of the EMR in dead end configuration. At the lowest feed substrate concentration tested (100 mg·L−1, consumption increased with flux (up to 7.9 × 103 mg·h−1·m−2 at 128 L·h−1·m−2, whereas at the highest substrate concentration (500 mg·L−1, it was shown that the reaction was limited by the oxygen content.

  17. Quinoline-degrading strain Pseudomonas aeruginosa KDQ4 isolated from coking activated sludge is capable of the simultaneous removal of phenol in a dual substrate system.

    Science.gov (United States)

    Zhang, Panhong; Jia, Rong; Zhang, Yuxiu; Shi, Peili; Chai, Tuanyao

    2016-11-09

    Quinoline is a refractory organic compound in the treatment of coking wastewater. The isolation of high efficiency quinoline-degrading bacteria from activated sludge and the evaluation of their degradation characteristics in the presence of phenol or in the actual coking wastewater are important for the improvement of effluent quality. The novel bacterial strain Pseudomonas aeruginosa KDQ4 was isolated from a quinoline enrichment culture obtained from the activated sludge of a coking wastewater treatment plant. The optimum temperature and initial pH for quinoline degradation were 33-38°C and 8-9, respectively. KDQ4 completely degraded 400 mg/L of quinoline within 24 h and 800 mg/L of phenol within 30 h. In the dual-substrate system, the removal efficiencies of quinoline and phenol at the same initial concentration (200 mg/L) by KDQ4 were 89% and 100% within 24 h, respectively, indicating that KDQ4 could simultaneously and quickly degrade quinoline and phenol in a coexistence system. Moreover, KDQ4 was able to adapt to actual coking wastewater containing high quinoline and phenol concentrations and rapidly remove them. KDQ4 also exhibited heterotrophic nitrification and aerobic denitrification potential under aerobic conditions. These results suggested a potential bioaugmentation role for KDQ4 in the removal of nitrogen-heterocyclic compounds and phenolics from coking wastewater.

  18. Metabolism of xenobiotics by Chlamydomonas reinhardtii: Phenol degradation under conditions affecting photosynthesis.

    Science.gov (United States)

    Nazos, Theocharis T; Kokarakis, Emmanouel J; Ghanotakis, Demetrios F

    2017-01-01

    In the present work, the biodegradation of phenol by axenic cultures of the unicellular microalga Chlamydomonas reinhardtii was investigated. Biodegradation proved to be a dynamic bioenergetic process, affected by changes in the culture conditions. Microalgae biodegraded defined amounts of phenol, as a result of the induced stress caused at high concentrations, despite the fact that this process proved to be energy demanding and thus affected growth of the culture. High levels of biodegradation were observed both in the absence of an alternative carbon source and in the presence of acetate as a carbon source. Biodegradation of phenol by Chlamydomonas proved to be an aerobic, photoregulated process. This is the first time that Chlamydomonas reinhardtii has been used for bioremediation purposes. This study has demonstrated that the most important factor in the biodegradation of phenol is the selection of the appropriate culture conditions (presence or absence of alternative carbon source, light intensity, and oxygen availability) that provide the best bioenergetic balance among growth, induced stress, and biodegradation of phenol.

  19. 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.

  20. The effect of microwave pretreatment of seeds on the stability and degradation kinetics of phenolic compounds in rapeseed oil during long-term storage.

    Science.gov (United States)

    Rękas, Agnieszka; Ścibisz, Iwona; Siger, Aleksander; Wroniak, Małgorzata

    2017-05-01

    Storage stability and degradation kinetics of phenolic compounds in rapeseed oil pressed from microwave treated seeds (0, 2, 4, 6, 8, 10min, 800W) during long-term storage (12months) at a temperature of 20°C was discussed in the current study. The dominant phenolic compound detected in rapeseed oil was canolol, followed by minor amounts of free phenolic acids and sinapine. The most pronounced effect of seeds microwaving was noted for canolol formation - after 10-min exposure the quantity of this compound was approximately 63-fold higher than in control oil. The degradation of phenolics during storage displayed pseudo first-order kinetics. Differences in the initial degradation rate (r 0 ) demonstrated significant impact of the period of seeds microwave exposure on the degradation rates of phenolic compounds. Results of the half-life calculation (t 1/2 ) showed that the storage stability of phenolic compounds was higher in oils produced from microwave treated rapeseeds than in control oil. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Reduced graphene oxide nanosheets decorated with Au-Pd bimetallic alloy nanoparticles towards efficient photocatalytic degradation of phenolic compounds in water

    Science.gov (United States)

    Darabdhara, Gitashree; Boruah, Purna K.; Borthakur, Priyakshree; Hussain, Najrul; Das, Manash R.; Ahamad, Tansir; Alshehri, Saad M.; Malgras, Victor; Wu, Kevin C.-W.; Yamauchi, Yusuke

    2016-04-01

    Reduced graphene oxide nanosheets decorated with Au-Pd bimetallic alloy nanoparticles are successfully prepared via a chemical approach consisting of reducing the metal precursors using ascorbic acid as reductant at an elevated temperature. The prepared nanocomposite is employed as a photocatalyst for the degradation of organic contaminants such as phenol, 2-chlorophenol (2-CP), and 2-nitrophenol (2-NP). The complete degradation of phenol is achieved after 300 min under natural sunlight irradiation whereas the degradation of 2-CP and 2-NP is completed after 180 min. The activity of the photocatalyst is evaluated considering several parameters such as the initial phenol concentration, the photocatalyst loading, and the pH of the solution. The degradation kinetics of all the compounds is carefully studied and found to follow a linear Langmuir-Hinshelwood model. Furthermore, the reusability of the photocatalyst is successfully achieved up to five cycles and the catalyst exhibits an excellent stability.Reduced graphene oxide nanosheets decorated with Au-Pd bimetallic alloy nanoparticles are successfully prepared via a chemical approach consisting of reducing the metal precursors using ascorbic acid as reductant at an elevated temperature. The prepared nanocomposite is employed as a photocatalyst for the degradation of organic contaminants such as phenol, 2-chlorophenol (2-CP), and 2-nitrophenol (2-NP). The complete degradation of phenol is achieved after 300 min under natural sunlight irradiation whereas the degradation of 2-CP and 2-NP is completed after 180 min. The activity of the photocatalyst is evaluated considering several parameters such as the initial phenol concentration, the photocatalyst loading, and the pH of the solution. The degradation kinetics of all the compounds is carefully studied and found to follow a linear Langmuir-Hinshelwood model. Furthermore, the reusability of the photocatalyst is successfully achieved up to five cycles and the catalyst

  2. Degradation of Substituted Phenols in a hybrid gas-liquid electrical discharge reactor

    Czech Academy of Sciences Publication Activity Database

    Lukeš, Petr; Locke, B.R.

    2005-01-01

    Roč. 44, č. 9 (2005), s. 2921-2930 ISSN 0888-5885 Institutional research plan: CEZ:AV0Z20430508 Keywords : Corona disc harge * hybrid reactor * hydroxyl radical * ozone * substituted phenols * water treatment Subject RIV: BL - Plasma and Gas Disc harge Physics Impact factor: 1.504, year: 2005

  3. In-liquid arc plasma jet and its application to phenol degradation

    KAUST Repository

    Liu, Jing-Lin Lin

    2018-02-07

    We present a new method for achieving chemical reactions induced by plasmas with liquids—an in-liquid arc plasma jet system—designed to have a few advantages over the existing methods. High-speed imaging and optical emission spectroscopy were adopted to highlight the physical aspects of the in-liquid arc plasma jet system, and the feasibility of the system was investigated in a wastewater treatment case with phenol as the model contaminant. We found that the specific energy input is a reasonable parameter by which to characterize the overall process. The phenol removal reaction could be modeled as a pseudo-first-order reaction, and the reaction constant became smaller as the phenol concentration increased. However, complete decomposition of the phenol into water and carbon dioxide required very high energy because the final intermediate, oxalic acid, is relatively stable. Detailed chemical and physical analyses, including byproducts, ions, solution acidity, and conductivity, were conducted to evaluate this new method for use in the appropriate applications.

  4. In-liquid arc plasma jet and its application to phenol degradation

    Science.gov (United States)

    Liu, Jing-Lin; Park, Hyun-Woo; Hamdan, Ahmad; Cha, Min Suk

    2018-03-01

    We present a new method for achieving chemical reactions induced by plasmas with liquids—an in-liquid arc plasma jet system—designed to have a few advantages over the existing methods. High-speed imaging and optical emission spectroscopy were adopted to highlight the physical aspects of the in-liquid arc plasma jet system, and the feasibility of the system was investigated in a wastewater treatment case with phenol as the model contaminant. We found that the specific energy input is a reasonable parameter by which to characterize the overall process. The phenol removal reaction could be modeled as a pseudo-first-order reaction, and the reaction constant became smaller as the phenol concentration increased. However, complete decomposition of the phenol into water and carbon dioxide required very high energy because the final intermediate, oxalic acid, is relatively stable. Detailed chemical and physical analyses, including byproducts, ions, solution acidity, and conductivity, were conducted to evaluate this new method for use in the appropriate applications.

  5. Methylene blue and 4-chloro phenol degradation by photo catalysis with ultraviolet light, using TiO2 as catalyst

    International Nuclear Information System (INIS)

    Martinez H, A.

    2010-01-01

    Within the decontamination and remediation processes of the contaminated waters, as the refining or tertiary processes are the Advanced Oxidation Technologies. Among this technology is the heterogeneous photo catalysis, which is the object of this work to de grate 4-chloro phenol and methylene blue, using as semiconductor commercial titanium dioxide (TiO 2 ). On the degradation the combination is exposed in the use of TiO 2 under gamma irradiation of 60 Co at different doses 400, 500, 800, 1000 and 1500 kGy. The organic compounds degradation was determined and the results show that to more radiation dose, the material is modified in such way that shows a major absorption of the organic compound, in the same way it is determined that to more dose which undergoes the TiO 2 generally a major degradation is observed, but also it is has to give a more time of previous stabilization, for that the degradation is observed of better way. (Author)

  6. Effects of introduced small wood in a degraded stream on fish community and functional diversity

    Science.gov (United States)

    Ken A. Sterling; Melvin L.  Warren Jr.

    2018-01-01

    Abstract - Though the effects of introduced wood on fishes is widely studied for salmonids in upland coldwater streams, there are few studies on this topic conducted in the Coastal Plain of the southeastern US. This research gap is problematic because the introduction of wood is a critical component of efforts aimed at conserving the threatened fish diversity of the...

  7. Prevention of polyurethane oxidative degradation with phenolic antioxidants covalently attached to the hard segments: structure-function relationships.

    Science.gov (United States)

    Stachelek, Stanley J; Alferiev, Ivan; Ueda, Masako; Eckels, Edward C; Gleason, Kevin T; Levy, Robert J

    2010-09-01

    Oxidative degradation of the polyurethane elastomeric (PU) components greatly reduces the efficacy of PU-containing cardiovascular devices. Covalently appending the phenol-based antioxidant, 4-substituted 2,6-di-tert-butylphenol (DBP), to PU hard segments effectively reduced oxidative degradation of the PU in vivo and in vitro in prior studies by our group. In these experiments, we analyze the contribution of the tethering molecule to the antioxidant capabilities of the DBP-modified PU. Bromoalkylation chemistry was used to link DBP to the hard segment of the polyether PU, Tecothane, via our original linker (PU-DBP) or variants containing side chains with one (PU-C-DBP) or three (PU-3C-DBP) carbons. Two additional DBP variants were fabricated in which the DBP group was appended to the alkyl chain via an oxygen atom (PU-O-DBP) or an amide linkage in the middle of the tether (PU-NHCO-DBP). All DBP variant films and unmodified control films were subject to oxidative degradation via 15-day immersion in a solution of 20% H(2)O(2) + 0.1M CoCl(2). At the end of the oxidation protocol, films were analyzed for the presence of oxidation-related endpoints via scanning electron microscopy, contact angle measurements, and Fourier transformation infrared spectroscopy (FTIR). All DBP-containing variants resisted oxidation damage significantly better than the unmodified control PU. SEM analysis of oxidized PU-C-DBP and PU-O-DBP showed evidence of surface cracking, consistent with oxidative degradation of the PU surfaces. Similarly, there was a trend in increased ether crosslinking, a marker for oxidative degradation, in PU-C-DBP and PU-NHCO-DBP films. Consistent with these FTIR results, both PU-C-DBP and PU-NHCO-DBP had significant reductions in measured surface hydrophobicity as a result of oxidation. These data show for the first time that the choice of linker molecule significantly affects the efficiency of the linked phenolic antioxidant. (c) 2010 Wiley Periodicals, Inc.

  8. The use of silica gel prepared by sol-gel method and polyurethane foam as microbial carriers in the continuous degradation of phenol.

    Science.gov (United States)

    Brányik, T; Kuncová, G; Páca, J

    2000-08-01

    A mixed microbial culture was immobilized by entrapment into silica gel (SG) and entrapment/ adsorption on polyurethane foam (PU) and ceramic foam. The phenol degradation performance of the SG biocatalyst was studied in a packed-bed reactor (PBR), packed-bed reactor with ceramic foam (PBRC) and fluidized-bed reactor (FBR). In continuous experiments the maximum degradation rate of phenol (q(s)max) decreased in the order: PBRC (598 mg l(-1) h(-1)) > PBR (PU, 471 mg l(-1)h(-1)) > PBR(SG, 394 mg l(-1) h(-1)) > FBR (PU, 161 mg l(-1) h(-1)) > FBR (SG, 91 mg l(-1) h(-1)). The long-term use of the SG biocatalyst in continuous phenol degradation resulted in the formation of a 100-200 microm thick layer with a high cell density on the surface of the gel particles. The abrasion of the surface layer in the FBR contributed to the poor degradation performance of this reactor configuration. Coating the ceramic foam with a layer of cells immobilized in colloidal SiO2 enhanced the phenol degradation efficiency during the first 3 days of the PBRC operation, in comparison with untreated ceramic packing.

  9. Ultrasound-assisted MnO2 catalyzed homolysis of peracetic acid for phenol degradation: The assessment of process chemistry and kinetics

    NARCIS (Netherlands)

    Rokhina, E.V.; Makarova, K.; Lathinen, M.; Golovina, E.A.; As, van H.; Virkutyte, J.

    2013-01-01

    The combination of peracetic acid (PAA) and heterogeneous catalyst (MnO2) was used for the degradation of phenol in an aqueous solution in the presence of ultrasound irradiation (US). As a relevant source of free radicals (e.g. OH), peracetic acid was comprehensively studied by means of electron

  10. Kinetics of the Degradation of Anthocyanins, Phenolic Acids and Flavonols During Heat Treatments of Freeze-Dried Sour Cherry Marasca Paste

    Directory of Open Access Journals (Sweden)

    Zoran Zorić

    2014-01-01

    Full Text Available The effect of heating temperature (80–120 °C and processing time (5–50 min on the stability of anthocyanins (cyanidin-3-glucosylrutinoside, cyanidin-3-rutinoside and cyanidin- 3-glucoside, quercetin-3-glucoside and phenolic acids (chlorogenic, neochlorogenic, p-coumaric and ferulic acids in freeze-dried Marasca sour cherry pastes was studied. The degradation rates of individual anthocyanins, quercetin-3-glucoside and phenolic acids followed the first order reaction kinetics. Cyanidin-3-glucoside was found to be the most unstable among the anthocyanins, together with p-coumaric and neochlorogenic acids among other phenols. Activation energies for anthocyanin degradation ranged from 42 (cyanidin-3-glucosylrutinoside to 55 kJ/mol (cyanidin-3-glucoside, and for other phenols from 8.12 (chlorogenic acid to 27 kJ/mol (neochlorogenic acid. By increasing the temperature from 80 to 120 °C, the reaction rate constant of cyanidin-3-glucosylrutinoside increased from 2.2·10–2 to 8.5·10–2 min–1, of p-coumaric acid from 1.12·10–2 to 2.5·10–2 min–1 and of quercetin-3-glucoside from 1.5·10–2 to 2.6·10–2 min–1. The obtained results demonstrate that at 80°C the half-life of anthocyanins ranges from 32.10 min for cyanidin-3-glucosylrutinoside to 45.69 min for cyanidin-3-rutinoside, and of other phenolic compounds from 43.39 for neochlorogenic acid to 66.99 min for chlorogenic acid. The results show that the heating temperature and duration affect the anthocyanins considerably more than the other phenols in terms of degradation.

  11. Morphology controlled bulk synthesis of disc-shaped WO{sub 3} powder and evaluation of its photocatalytic activity for the degradation of phenols

    Energy Technology Data Exchange (ETDEWEB)

    Aslam, M. [Centre of Excellence in Environmental Studies (CEES), King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Ismail, Iqbal M.I. [Centre of Excellence in Environmental Studies (CEES), King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Chemistry Department, Faculty of Science, King Abdulaziz University, PO Box 80203, Jeddah 21589 (Saudi Arabia); Chandrasekaran, S. [Centre of Excellence in Environmental Studies (CEES), King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Hameed, A., E-mail: afmuhammad@kau.edu.sa [Centre of Excellence in Environmental Studies (CEES), King Abdulaziz University, Jeddah 21589 (Saudi Arabia); National Centre for Physics, Quaid-e-Azam University, Islamabad 44000 (Pakistan)

    2014-07-15

    Graphical abstract: - Highlights: • User friendly procedure for the synthesis of disc-shaped WO{sub 3}. • Superoxide anion radicals are the major contributors in photocatalytic degradation process. • Electron withdrawing substituents facilitates the degradation process. • Nitrite ions are converted to NO{sub 2} gas in 2-nitophenol degradation. - Abstract: The surfactant assisted synthesis of disc-shaped WO{sub 3} powder and its photocatalytic performance in sunlight exposure is reported. UV–vis DRS, XRD and FESEM characterized the synthesized WO{sub 3}. The synthesized powder exhibited a bandgap of ∼2.55 eV with cubic lattice and high crystallinity. The photocatalytic activity of the synthesized WO{sub 3} was examined for the degradation of phenol, resorcinol, 2-chlorophenol and 2-nitrophenol in complete spectrum and visible segment of sunlight. The highly efficient degradation/mineralization of 2-chloro and 2-nitrophenol compared to that of phenol and resorcinol, under identical experimental conditions, suggested the regulatory role of substituents attached to the aromatic ring in degradation/mineralization process. The time-scale HPLC degradation profiles, identification of intermediates by GC-MS and removal of organic carbon during the course of reaction were utilized to approximate the possible route of degradation/mineralization of phenolic substrates. The measurement of the anions released during the photocatalytic process was used to identify the nature of the major oxidants (O{sub 2}{sup •} {sup −}, OH{sup •} ) and the possible interaction sites. A significant decrease in the photocatalytic activity of synthesized WO{sub 3}, ∼50%, was observed in visible portion of sunlight however, a sustained activity was observed in the repeated exposures.

  12. Differential Gene Expression by Lactobacillus plantarum WCFS1 in Response to Phenolic Compounds Reveals New Genes Involved in Tannin Degradation.

    Science.gov (United States)

    Reverón, Inés; Jiménez, Natalia; Curiel, José Antonio; Peñas, Elena; López de Felipe, Félix; de Las Rivas, Blanca; Muñoz, Rosario

    2017-04-01

    Lactobacillus plantarum is a lactic acid bacterium that can degrade food tannins by the successive action of tannase and gallate decarboxylase enzymes. In the L. plantarum genome, the gene encoding the catalytic subunit of gallate decarboxylase ( lpdC , or lp_2945 ) is only 6.5 kb distant from the gene encoding inducible tannase ( L. plantarum tanB [ tanB Lp ], or lp_2956 ). This genomic context suggests concomitant activity and regulation of both enzymatic activities. Reverse transcription analysis revealed that subunits B ( lpdB , or lp_0271 ) and D ( lpdD , or lp_0272 ) of the gallate decarboxylase are cotranscribed, whereas subunit C ( lpdC , or lp_2945 ) is cotranscribed with a gene encoding a transport protein ( gacP , or lp_2943 ). In contrast, the tannase gene is transcribed as a monocistronic mRNA. Investigation of knockout mutations of genes located in this chromosomal region indicated that only mutants of the gallate decarboxylase (subunits B and C), tannase, GacP transport protein, and TanR transcriptional regulator ( lp_2942 ) genes exhibited altered tannin metabolism. The expression profile of genes involved in tannin metabolism was also analyzed in these mutants in the presence of methyl gallate and gallic acid. It is noteworthy that inactivation of tanR suppresses the induction of all genes overexpressed in the presence of methyl gallate and gallic acid. This transcriptional regulator was also induced in the presence of other phenolic compounds, such as kaempferol and myricetin. This study complements the catalog of L. plantarum expression profiles responsive to phenolic compounds, which enable this bacterium to adapt to a plant food environment. IMPORTANCE Lactobacillus plantarum is a bacterial species frequently found in the fermentation of vegetables when tannins are present. L. plantarum strains degrade tannins to the less-toxic pyrogallol by the successive action of tannase and gallate decarboxylase enzymes. The genes encoding these enzymes are

  13. Contribution of phenolic compounds to food flavors: Strecker-type degradation of amines and amino acids produced by o- and p-diphenols.

    Science.gov (United States)

    Delgado, Rosa M; Zamora, Rosario; Hidalgo, Francisco J

    2015-01-14

    The ability of 20 phenolic derivatives to produce the Strecker-type degradation of phenylalanine and phenylglycine methyl ester was studied to investigate both the direct degradation of amino acids and amines by phenolic compounds in the absence of added oxidants and the effect of the number and positions of hydroxyl groups in the aromatic ring of the phenolic compound in relation to its ability to produce carbonyl derivatives from amino compounds. The obtained results showed that polyphenols can produce the Strecker degradation of amino acids and amines in the absence of added oxidants. The only requisite for producing the reaction is the presence of two hydroxyl groups in ortho or para positions. However, the presence of two hydroxyl groups in meta position in an additional aromatic ring can inhibit the Strecker-degrading ability of the hydroxyl groups in ortho or para positions. A reaction pathway that explains all of these findings is proposed. In addition, the effect of reaction conditions on the obtained reaction yields was studied. Activation energies (Ea) for phenylacetaldehyde formation from phenylalanine in the presence of hydroquinone, 1,2,4-trihydroxybenzene, and benzoquinone were 32.9, 31.5, and 28.8 kJ/mol, respectively.

  14. Identification of the Phenol Functionality in Deprotonated Monomeric and Dimeric Lignin Degradation Products via Tandem Mass Spectrometry Based on Ion-Molecule Reactions with Diethylmethoxyborane

    Science.gov (United States)

    Zhu, Hanyu; Max, Joann P.; Marcum, Christopher L.; Luo, Hao; Abu-Omar, Mahdi M.; Kenttämaa, Hilkka I.

    2016-11-01

    Conversion of lignin into smaller molecules provides a promising alternate and sustainable source for the valuable chemicals currently derived from crude oil. Better understanding of the chemical composition of the resulting product mixtures is essential for the optimization of such conversion processes. However, these mixtures are complex and contain isomeric molecules with a wide variety of functionalities, which makes their characterization challenging. Tandem mass spectrometry based on ion-molecule reactions has proven to be a powerful tool in functional group identification and isomer differentiation for previously unknown compounds. This study demonstrates that the identification of the phenol functionality, the most commonly observed functionality in lignin degradation products, can be achieved via ion-molecule reactions between diethylmethoxyborane (DEMB) and the deprotonated analyte in the absence of strongly electron-withdrawing substituents in the ortho- and para-positions. Either a stable DEMB adduct or an adduct that has lost a methanol molecule (DEMB adduct-MeOH) is formed for these ions. Deprotonated phenols with an adjacent phenol or hydroxymethyl functionality or a conjugated carboxylic acid functionality can be identified based on the formation of DEMB adduct-MeOH. Deprotonated compounds not containing the phenol functionality and phenols containing an electron-withdrawing ortho- or para-substituent were found to be unreactive toward diethylmethoxyborane. Hence, certain deprotonated isomeric compounds with phenol and carboxylic acid, aldehyde, carboxylic acid ester, or nitro functionalities can be differentiated via these reactions. The above mass spectrometry method was successfully coupled with high-performance liquid chromatography for the analysis of a complex biomass degradation mixture.

  15. Visible-Light Degradation of Dyes and Phenols over Mesoporous Titania Prepared by Using Anthocyanin from Red Radish as Template

    Directory of Open Access Journals (Sweden)

    Zhiying Yan

    2014-01-01

    Full Text Available Heterogeneous photocatalysis is able to operate effectively to eliminate organic compounds from wastewater in the presence of semiconductor photocatalyst and a light source. Although photosensitization of titania by organic dyes is one of the conventional ways for visible-light utilization of titania, previous studies have not yet addressed the use of natural food coloring agents as templates in the synthesis of mesostructured materials, let alone the simultaneous achievement of highly crystalline mesoscopic framework and visible-light photocatalytic activity. In this work, anthocyanin, a natural pigment from red radish was directly used as template in synthesis of highly crystalline mesoporous titania. The synthesized mesoporous titania samples were characterized by a combination of various physicochemical techniques, such as XRD, SEM, HRTEM, nitrogen adsorption/desorption, and diffuse reflectance UV-Vis. The prepared mesoporous titania photocatalyst exhibited significant activity under visible-light irradiation for the degradation of dyes and phenols due to its red shift of band-gap-absorption onset and visible-light response as a result of the incorporation of surface carbon species.

  16. Degradation kinetics of peroxidase enzyme, phenolic content, and physical and sensorial characteristics in broccoli (Brassica oleracea L. ssp. Italica) during blanching.

    Science.gov (United States)

    Gonçalves, Elsa M; Pinheiro, Joaquina; Alegria, Carla; Abreu, Marta; Brandão, Teresa R S; Silva, Cristina L M

    2009-06-24

    The effects of water blanching treatment on peroxidase inactivation, total phenolic content, color parameters [-a*/b* and hue (h degrees*)], texture (maximum shear force), and sensory attributes (color and texture, evaluated by a trained panel) of broccoli (Brassica oleracea L. ssp. Italica) were studied at five temperatures (70, 75, 80, 85, and 90 degrees C). Experimental results showed that all studied broccoli quality parameters suffered significative changes due to blanching treatments. The vegetal total phenolic content showed a marked decline. Degradation on objective color and texture measurements and alterations in sensorial attributes were detected. Correlations between sensory and instrumental measurements have been found. Under the conditions 70 degrees C and 6.5 min or 90 degrees C and 0.4 min, 90% of the initial peroxidase activity was reduced. At these conditions, no significant alterations were detected by panelists, and a small amount of phenolic content was lost (ca. 16 and 10%, respectively). The peroxidase inactivation and phenolic content degradation were found to follow first-order reaction models. The zero-order reaction model showed a good fit to the broccoli color (-a*/b* and h degrees*), texture, and sensory parameters changes. The temperature effect was well-described by the Arrhenius law.

  17. Expression and characteristics of manganese peroxidase from Ganoderma lucidum in Pichia pastoris and its application in the degradation of four dyes and phenol.

    Science.gov (United States)

    Xu, Hui; Guo, Meng-Yuan; Gao, Yan-Hua; Bai, Xiao-Hui; Zhou, Xuan-Wei

    2017-02-23

    Manganese peroxidase (MnP) of white rot basidiomycetes, an extracellular heme enzyme, is part of a peroxidase superfamily that is capable of degrading the different phenolic compounds. Ganoderma, a white rot basidiomycete widely distributed worldwide, could secrete lignin-modifying enzymes (LME), including laccase (Lac), lignin peroxidases (LiP) and MnP. After the selection of a G. lucidum strain from five Ganoderma strains, the 1092 bp full-length cDNA of the MnP gene, designated as G. lucidum MnP (GluMnP1), was cloned from the selected strain. We subsequently constructed an eukaryotic expression vector, pAO815:: GlMnP, and transferred it into Pichia pastoris SMD116. Recombinant GluMnP1 (rGluMnP1) was with a yield of 126 mg/L and a molecular weight of approximately 37.72 kDa and a specific enzyme activity of 524.61 U/L. The rGluMnP1 could be capable of the decolorization of four types of dyes and the degradation of phenol. Phenol and its principal degradation products including hydroquinone, pyrocatechol, resorcinol, benzoquinone, were detected successfully in the experiments. The rGluMnP1 could be effectively expressed in Pichia pastoris and with a higher oxidation activity. We infer that, in the initial stages of the reaction, the catechol-mediated cycle should be the principal route of enzymatic degradation of phenol and its oxidation products. This study highlights the potential industrial applications associated with the production of MnP by genetic engineering methods, and the application of industrial wastewater treatment.

  18. Microbial population responses to pH and salt shock during phenols degradation under high salt conditions revealed by RISA and AFDRA.

    Science.gov (United States)

    Yan, Bin; Wang, Ping; Liao, Wenchao; Ye, Qian; Xu, Meilan; Zhou, Jiti

    2013-01-01

    The responses of microbial community to pH and salt shock during phenols degradation under high salt conditions were revealed by two DNA fingerprint methods, i.e. ribosomal intergenic spacer analysis (RISA) and amplified functional DNA restriction analysis (AFDRA), together with 16S rDNA clone library analysis. It was shown that the phenols removal rate was improved with increasing NaCl concentration from 0 to 50 mg/L, and could remain at a high level even in the presence of 100 mg/L NaCl. The degradation efficiency remained stable under neutral conditions (pH 7.0-9.0), but decreased sharply under acidic (below pH 5.0) or more alkaline conditions (above pH 10.0). The community structure was dramatically changed during salt fluctuations, with Halomonas sp. and Marinobacter sp. as the predominant salt-tolerant species. Meanwhile, Marinobacter sp. and Alcaligenes faecalis sp. were the major species which might play the key role for stabilizing the treatment systems under different pH conditions. Moreover, the changes of phenol hydroxylase genes were analyzed by AFDRA, which showed that these functional genes were substantially different under any shock conditions.

  19. Efficient interfacial charge transfer through plasmon sensitized Ag@Bi2O3hierarchical photoanodes for photoelectrocatalytic degradation of chlorinated phenols.

    Science.gov (United States)

    Eswar, Neerugatti KrishnaRao; Adhikari, Sangeeta; Ramamurthy, Praveen C; Madras, Giridhar

    2018-01-31

    The present work demonstrates an extremely proficient and robust study of efficient interfacial charge transfer through plasmonic Ag decorated Bi 2 O 3 hierarchical photoanodes for the photoelectrochemical treatment of chlorinated phenols. Unique 2D flake-like Bi 2 O 3 hierarchical nanostructures were grown onto a fluorine-doped tin oxide (FTO) substrate by a simple chemical bath deposition method using triethanolamine as complexing agent. The formation of Bi 2 O 3 on FTO was governed by the decomposition of a nucleated bismuth-hydroxyl complex (Bi 2 O 1-x (OH) x ) and modification to the electrode was carried out by the deposition of Ag via a chemical reduction method using hydrazine hydrate. Both the fabricated electrodes were well characterized for their photo- and electro-optical properties. Efficient charge separation was observed due to the surface plasmon resonance phenomenon of silver nanoparticles with the favorable intrinsic properties of Bi 2 O 3 under application of a small electric bias of 1 V preventing the recombination of charge carriers and thereby increasing the rate of photoelectrocatalytic degradation of the chlorinated phenols. PEC degradation using the Ag@Bi 2 O 3 photoelectrode followed the trend 4-CP TCP attack at the chlorinated positions by reactive oxygen species with increasing chlorine substitution and also due to the absence of an expected chain reaction of the generated chlorine radicals (Cl˙) during the PEC reaction. The PEC activity of Ag@Bi 2 O 3 was 1.5 times higher than a Bi 2 O 3 nanoflake electrode for 4-CP over 2 h. The fabricated Ag@Bi 2 O 3 proved to be an efficient photoelectrode with synergistic solar-induced photoactivity. A detailed mechanistic study in the presence of scavengers suggests degradation by produced hydroxyl radical species. Thus, physical insights into the degradation of chlorinated phenols were obtained.

  20. Preparation and Characterization of Au/Pd Modified-TiO2 Photocatalysts for Phenol and Toluene Degradation under Visible Light—The Effect of Calcination Temperature

    Directory of Open Access Journals (Sweden)

    Anna Cybula

    2014-01-01

    Full Text Available Rutile loaded with Au/Pd nanoparticles was prepared using a water-in-oil microemulsion system of water/AOT/cyclohexane followed by calcination. The effect of calcination temperature (from 350 to 700°C on the structure of Au/Pd nanoparticles deposited at rutile matrix and the photocatalytic properties of Au/Pd-TiO2 was investigated in two model reactions (toluene degradation in gas phase and phenol degradation in aqueous phase. Toluene was irradiated over Au/Pd-TiO2 using light emitting diodes (LEDs, λmax⁡ = 415 nm. The sample 0.5 mol% Pd/TiO2 exhibited the highest activity under visible light irradiation in gas and aqueous phase reaction among all photocatalysts calcined at 350°C, while the sample modified only with gold nanoparticles showed the lowest activity. The Au/Pd-TiO2 sample calcinated at 350°C possesses the highest photocatalytic activity when degrading phenol under visible light, which is 14 times higher than that of the one calcinated at 450°C. It was observed that increasing temperature from 350 to 700°C during calcination step caused segregation of metals and finally resulted in photoactivity drop.

  1. Quick photo-Fenton degradation of phenolic compounds by Cu/Al2O3-MCM-41 under visible light irradiation: small particle size, stabilization of copper, easy reducibility of Cu and visible light active material.

    Science.gov (United States)

    Pradhan, Amaresh C; Nanda, Binita; Parida, K M; Das, Mira

    2013-01-14

    The present study reports the photo-Fenton degradation of phenolic compounds (phenol, 2-chloro-4-nitrophenol and 4-chloro-2-nitrophenol) in aqueous solution using mesoporous Cu/Al(2)O(3)-MCM-41 nanocomposite as a heterogeneous photo-Fenton-like catalyst. The in situ incorporation of mesoporous Al(2)O(3) (MA) into the framework of MCM-41 (sol-gel method) forms Al(2)O(3)-MCM-41 and wetness impregnation of Cu(II) on Al(2)O(3)-MCM-41 generates mesoporous Cu/Al(2)O(3)-MCM-41 composite. The effects of pH and H(2)O(2) concentration on degradation of phenol, 2-chloro-4-nitrophenol and 4-chloro-2-nitrophenol are studied. Kinetics analysis shows that the photocatalytic degradation reaction follows a first-order rate equation. Mesoporous 5 Cu/Al(2)O(3)-MCM-41 is found to be an efficient photo-Fenton-like catalyst for the degradation of phenolic compounds. It shows nearly 100% degradation in 45 min at pH 4. The combined effect of small particle size, stabilization of Cu(2+) on the support Al(2)O(3)-MCM-41, ease reducibility of Cu(2+) and visible light activeness are the key factors for quick degradation of phenolic compounds by Cu/Al(2)O(3)-MCM-41.

  2. Enhanced degradation of phenolic compounds in coal gasification wastewater by a novel integration of micro-electrolysis with biological reactor (MEBR) under the micro-oxygen condition.

    Science.gov (United States)

    Ma, Weiwei; Han, Yuxing; Xu, Chunyan; Han, Hongjun; Ma, Wencheng; Zhu, Hao; Li, Kun; Wang, Dexin

    2018-03-01

    The aim of this work was to study an integration of micro-electrolysis with biological reactor (MEBR) for strengthening removal of phenolic compounds in coal gasification wastewater (CGW). The results indicated MEBR achieved high efficiencies in removal of COD and phenolic compounds as well as improvement of biodegradability of CGW under the micro-oxygen condition. The integrated MEBR process was more favorable to improvement of the structural stability of activated sludge and biodiversity of specific functional microbial communities. Especially, Shewanella and Pseudomonas were enriched to accelerate the extracellular electron transfer, finally facilitating the degradation of phenolic compounds. Moreover, MEBR process effectively relieved passivation of Fe-C filler surface and prolonged lifespan of Fe-C filler. Accordingly, the synergetic effect between iron-carbon micro-electrolysis (ICME) and biological action played a significant role in performance of the integrated process. Therefore, the integrated MEBR was a promising practical process for enhancing CGW treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Photocatalytic degradation of 2-propanol and phenol using Au loaded MnWO4 nanorod under visible light irradiation

    CSIR Research Space (South Africa)

    Chakraborty, AK

    2012-06-01

    Full Text Available nanorod. The prepared Au loaded MnWO4 nanorod demonstrated greatly enhanced photocatalytic activity in decomposing 2-propanol and evolving CO2 in gas phase and phenol in aqueous phase compared to bare MnWO4 and commercial TiO2 nanoparticles (Degussa P25...

  4. The Effect of Antioxidants on Suppression of Thermal Degradation of Insulation Material

    Science.gov (United States)

    Sagae, Masahiro; Sekii, Yasuo; Yoshino, Hiroto; Miyake, Koujirou

    Thermal degradation of EPDM and the effect of antioxidants on the degradation of EPDM was investigated. Using FT-IR (Fourier transform infrared spectrophotometer) micrometer the degree of degradation was analyzed. A new evaluation method of mapping measurement was introduced and showed to be very useful. Among oxidants studied, the phenolic antioxidant 4,4'-tiobis(3-methyl-6-tert.-Butyl phenol was confirmed to be useful. A synergetic effects between phenolic antioxidant 2,2'-methylene- bis (4-methyl-6-tert.buthylphenol) and sulfur type antioxidant, dilauryl thiodipropionate, was also confirmed. The temperature dependence of thermal degradation of EPDM was also analyzed.

  5. Investigating Marine Dissolved Organic Matter Fluorescence Transformations with Organic Geochemical Proxies in a Growth and Degradation Experiment using Amino Acids, Amino Sugars, and Phenols

    Science.gov (United States)

    Shields, M. R.; Bianchi, T. S.; Osburn, C. L.; Kinsey, J. D.; Ziervogel, K.; Schnetzer, A.

    2017-12-01

    The origin and mechanisms driving the formation of fluorescent dissolved organic matter (FDOM) in the open ocean remain unclear. Although recent studies have attempted to deconvolve the chemical composition and source of marine FDOM, these studies have been qualitative in nature. Here, we investigate these transformations using a more quantitative biomarker approach in a controlled growth and degradation experiment. In this experiment, a natural assemblage of phytoplankton was collected off the coast of North Carolina and incubated within roller bottles containing 0.2 µm-filtered North Atlantic surface water amended with f/2 nutrients. Samples were collected at the beginning (day 0), during exponential growth (day 13), stationary (day 20), and degradation (day 62) phases of the phytoplankton incubation. Amino acids, amino sugars, and phenolic compounds of the dissolved (DOM) were measured in conjunction with enzyme assays and bacterial counts to track shifts in OM quality as FDOM formed and was then transformed throughout the experiment. The results from the chemical analyses showed that the OM composition changed significantly from the initial and exponential phases to the stationary and degradation phases of the experiment. The percentage of aromatic amino acids to the total amino acid pool increased significantly during the exponential phase of phytoplankton growth, but then decreased significantly during the stationary and degradation phases. This increase was positively correlated to the fractional contribution of the protein-like peak in fluorescence to the total FDOM fluorescence. An increase in the concentration of amino acid degradation products during the stationary and degradation phases suggests that compositional changes in OM were driven by microbial transformation. This was further supported by a concurrent increase in total enzyme activity and increase in "humic-like" components of the FDOM. These findings link the properties and formation of FDOM

  6. Enhanced photocatalytic degradation of aqueous phenol and Cr(VI) over visible-light-driven TbxOy loaded TiO2-oriented nanosheets

    International Nuclear Information System (INIS)

    Lu, Dingze; Yang, Minchen; Fang, Pengfei; Li, Chunhe; Jiang, Lulu

    2017-01-01

    Highlights: • Tb-TNSs with high stability and regeneration behavior were prepared by one-pot method. • Loaded Tb x O y nanoparticles lead to obvious increase of the Ti 3+ ions content. • Loaded Tb x O y results in the changes in the structure of the TNSs and red shift. • Loaded Tb x O y can effectively trap electrons to enhance the separation of charges. • Tb-TNSs exhibit excellent synergistic photocatalytic activities for Cr(VI) and phenol. - Abstract: A visible-light-driven Tb x O y loaded TiO 2 -oriented nanosheets (Tb-TNSs) of 3.6 nm thick and specific surface area of 240–350 m 2 /g provided with highly dispersed Tb x O y nanoparticles of 1–2 nm over the surfaces were synthesized using a one-pot hydrothermal route. Loaded Tb x O y nanoparticles influenced morphology, structure, and optical properties of the TNSs. The XPS results showed that Tb 3+ and Tb 4+ co-exist in Tb-TNSs, and loaded Tb x O y resulted in changes in binding energies of Ti and O. The amount of Ti 3+ increased gradually with the amount of loaded Tb x O y nanoparticles. FL and surface photocurrent spectra results indicated that an appropriate amount of Tb x O y (≤1.0 at.%) loading can effectively improve the separation efficiency of charge carriers. The visible-light-driven photocatalysis could be measured by the removal of phenol or dichromate separately along with synergistic degradation in phenol-Cr(VI) coexistence system. The optimum photocatalytic activity was obtained at Tb/Ti = 1.0 at.% under degradation of aqueous phenol or Cr(VI) solution. Besides, the desorbed Tb-TNSs could be easily regenerated by remedying the damaged structure and reused with excellent performance. High regeneration and stability of photocatalysts were confirmed by seven cyclic tests. An alternant mechanism for the enhanced visible-light-driven photocatalytic activity was also considered.

  7. Evaluation of sunlight induced structural changes and their effect on the photocatalytic activity of V{sub 2}O{sub 5} for the degradation of phenols

    Energy Technology Data Exchange (ETDEWEB)

    Aslam, M. [Centre of Excellence in Environmental Studies (CEES), King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Ismail, Iqbal M.I. [Centre of Excellence in Environmental Studies (CEES), King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Chemistry Department, Faculty of Science, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Salah, Numan [Centre of Nanotechnology, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Chandrasekaran, S. [Centre of Excellence in Environmental Studies (CEES), King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Qamar, M.Tariq [Centre of Excellence in Environmental Studies (CEES), King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Chemistry Department, Faculty of Science, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Hameed, A., E-mail: afmuhammad@kau.edu.sa [Centre of Excellence in Environmental Studies (CEES), King Abdulaziz University, Jeddah 21589 (Saudi Arabia); National Centre for Physics, Quaid-e-Azam University, Islamabad 44000 (Pakistan)

    2015-04-09

    Highlights: • The interaction of UV photons of sunlight induces defects in V{sub 2}O{sub 5}. • The photon induced defects promotes the trapping and transfer of excited electrons. • The nature of the substituent at 2-position affects the degradation process. • The formation of the intermediates is influenced by the nature of substituents. • The released ions are subjected further transformation. - Abstract: Despite knowing the fact that vanadium pentoxide is slightly soluble in aqueous medium, its photocatalytic activity was evaluated for the degradation of phenol and its derivatives (2-hydroxyphenol, 2-chlorophenol, 2-aminophenol and 2-nitrophenol) in natural sunlight exposure. The prime objective of the study was to differentiate between the homogeneous and heterogeneous photocatalysis incurred by dissolved and undissolved V{sub 2}O{sub 5} in natural sunlight exposure. V{sub 2}O{sub 5} was synthesized by chemical precipitation procedure using Triton X-100 as morphology mediator and characterized by DRS, PLS, Raman, FESEM and XRD. A lower solubility of ∼5% per 100 ml of water at 23 °C was observed after calcination at 600 °C. The study revealed no contribution of the dissolved V{sub 2}O{sub 5} in the photocatalytic process. In sunlight exposure, V{sub 2}O{sub 5} powder exhibited substantial activity for the degradation, however, a low mineralization of phenolic substrates was observed. The initial low activity of V{sub 2}O{sub 5} followed by a sharp increase both in degradation and mineralization in complete spectrum sunlight exposure, was further investigated that revealed the decrease in the bandgap and the reduction in the particle size with the interaction of UV photons (<420 nm) as this effect was not observable in the exposure of visible region of sunlight. The role of the chemically different substituents attached to an aromatic ring at 2-positions and the secondary interaction of released ions during the degradation process with the reactive

  8. UV-Vis-Induced Degradation of Phenol over Magnetic Photocatalysts Modified with Pt, Pd, Cu and Au Nanoparticles

    Directory of Open Access Journals (Sweden)

    Izabela Wysocka

    2018-01-01

    Full Text Available The combination of TiO2 photocatalyst and magnetic oxide nanoparticles enhances the separation and recoverable properties of nanosized TiO2 photocatalyst. Metal-modified (Me = Pd, Au, Pt, Cu TiO2/SiO2@Fe3O4 nanocomposites were prepared by an ultrasonic-assisted sol-gel method. All prepared samples were characterized by X-ray powder diffraction (XRD analysis, Brunauer-Emmett-Teller (BET method, X-ray photoelectron spectroscopy (XPS, scanning transmission electron microscopy (STEM, Mott-Schottky analysis and photoluminescence spectroscopy (PL. Phenol oxidation pathways of magnetic photocatalysts modified with Pt, Pd, Cu and Au nanoparticles proceeded by generation of reactive oxygen species, which oxidized phenol to benzoquinone, hydroquinone and catechol. Benzoquinone and maleic acid were products, which were determined in the hydroquinone oxidation pathway. The highest mineralization rate was observed for Pd-TiO2/SiO2@Fe3O4 and Cu-TiO2/SiO2@Fe3O4 photocatalysts, which produced the highest concentration of catechol during photocatalytic reaction. For Pt-TiO2/SiO2@Fe3O4 nanocomposite, a lack of catechol after 60 min of irradiation resulted in low mineralization rate (CO2 formation. It is proposed that the enhanced photocatalytic activity of palladium and copper-modified photocatalysts is related to an increase in the amount of adsorption sites and efficient charge carrier separation, whereas the keto-enol tautomeric equilibrium retards the rate of phenol photomineralization on Au-TiO2/SiO2@Fe3O4. The magnetization hysteresis loop indicated that the obtained hybrid photocatalyst showed magnetic properties and therefore could be easily separated after treatment process.

  9. Measures introduced for improving the resistance against degradation by corrosion of steam generators in Framatome designed PWR'S

    International Nuclear Information System (INIS)

    Smith, K.; Slama, G.; Sort, M.

    1986-01-01

    The operational experience of FRAMATOME plants now extends to more than 8 years with a total of 35 PWR plants commissioned and in operation for periods of time varying from 1 to 7.5 years. Overall, the 1.600 Steam Generator (S.G.) tubes are significantly free from secondary side corrosion problems. On the primary side, several instances of stress corrosion cracking have occurred, this cracking is principally at the transitions of the mechanical roll in 1.600 Mill Annealed tubing. This paper reviews the design and material changes which have been, or are being, introduced to improve the resistance to corrosion. In addition, the application is described of the FRAMATOME shot peening surface treatment to the primary side tube surface of the mechanically rolled expansions. The objective of this treatment is to increase the resistance to primary side stress corrosion cracking by appreciable reduction of the surface tensile stresses. The steam generators of several operational plants have been successfully treated by this technique

  10. Hydroxyl radical scavenging assay of phenolics and flavonoids with a modified cupric reducing antioxidant capacity (CUPRAC) method using catalase for hydrogen peroxide degradation.

    Science.gov (United States)

    Ozyürek, Mustafa; Bektaşoğlu, Burcu; Güçlü, Kubilay; Apak, Reşat

    2008-06-02

    Hydroxyl radicals (OH) generated in the human body may play an important role in tissue injury at sites of inflammation in oxidative stress-originated diseases. As a more convenient, efficient, and less costly alternative to HPLC/electrochemical detection techniques and to the nonspecific, low-yield deoxyribose (TBARS) test, we used a salicylate probe for detecting OH generated by the reaction of iron(II)-EDTA complex with H(2)O(2). The produced hydroxyl radicals attack both the salicylate probe and the hydroxyl radical scavengers that are incubated in solution for 10 min. Added radical scavengers compete with salicylate for the OH produced, and diminish chromophore formation from Cu(II)-neocuproine. At the end of the incubation period, the reaction was stopped by adding catalase. With the aid of this reaction, a kinetic approach was adopted to assess the hydroxyl radical scavenging properties of polyphenolics, flavonoids and other compounds (e.g., ascorbic acid, glucose, mannitol). A second-order rate constant for the reaction of the scavenger with OH could be deduced from the inhibition of colour formation due to the salicylate probe. In addition to phenolics and flavonoids, five kinds of herbs were evaluated for their OH scavenging activity using the developed method. The modified CUPRAC (cupric ion reducing antioxidant capacity) assay proved to be efficient for ascorbic acid, gallic acid and chlorogenic acid, for which the deoxyribose assay test is basically nonresponsive. An important contribution of this developed assay is the inhibition of the Fenton reaction with catalase degradation of hydrogen peroxide so that the remaining H(2)O(2) would neither give a CUPRAC absorbance nor involve in redox cycling of phenolic antioxidants, enabling the rapid assay of polyphenolics.

  11. Ammonia-modified graphene sheets decorated with magnetic Fe{sub 3}O{sub 4} nanoparticles for the photocatalytic and photo-Fenton degradation of phenolic compounds under sunlight irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Boruah, Purna K. [Advanced Materials Group, Materials Sciences and Technology Division, CSIR-North East Institute of Science & Technology, Jorhat 785006 (India); Academy of Scientific and Innovative Research (AcSIR) (India); Sharma, Bhagyasmeeta [Advanced Materials Group, Materials Sciences and Technology Division, CSIR-North East Institute of Science & Technology, Jorhat 785006 (India); Karbhal, Indrapal; Shelke, Manjusha V. [Academy of Scientific and Innovative Research (AcSIR) (India); Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory, Pune-11008, Maharashtra (India); Das, Manash R., E-mail: mnshrdas@yahoo.com [Advanced Materials Group, Materials Sciences and Technology Division, CSIR-North East Institute of Science & Technology, Jorhat 785006 (India); Academy of Scientific and Innovative Research (AcSIR) (India)

    2017-03-05

    Highlights: • Ammonia-modified graphene sheets decorated with magnetic Fe{sub 3}O{sub 4} nanoparticles. • Photocatalytic and photo-Fenton degradation of phenolic compounds. • An excellent reusability of the nanocomposite was observed up to ten cycles. - Abstract: Synthesis of easily separable and eco-friendly efficient catalyst with both photocatalytic and photo-Fenton degradation properties is of great importance for environment remediation application. Herein, ammonia-modified graphene (AG) sheets decorated with Fe{sub 3}O{sub 4} nanoparticles (AG/Fe{sub 3}O{sub 4}) as a magnetically recoverable photocatalyst by a simple in situ solution chemistry approach. First, we have functionalized graphene oxide (GO) sheets by amide functional group and then Fe{sub 3}O{sub 4} nanoparticles (NPs) are doped onto the functionalized GO surface. The AG/Fe{sub 3}O{sub 4} nanocomposite showed efficient photocatalytic activity towards degradation of phenol (92.43%), 2-nitrophenol (2-NP) (98%) and 2-chlorophenol (2-CP) (97.15%) within 70–120 min. Consequently, in case of photo-Fenton degradation phenomenon, 93.56% phenol, 98.76% 2-NP and 98.06% of 2-CP degradation were achieved within 50–80 min using AG/Fe{sub 3}O{sub 4} nanocomposite under sunlight irradiation. The synergistic effect between amide functionalized graphene and Fe{sub 3}O{sub 4} nanoparticles (NPs) enhances the photocatalytic activity by preventing the recombination rate of electron-hole-pair in Fe{sub 3}O{sub 4} NPs. Furthermore, the remarkable reusability of the AG/Fe{sub 3}O{sub 4} nanocomposite was observed up to ten cycles during the photocatalytic degradation of these phenolic compounds.

  12. Enhancement of photocatalytic properties of TiO2 nanoparticles doped with CeO2 and supported on SiO2 for phenol degradation

    International Nuclear Information System (INIS)

    Hao, Chunjing; Li, Jing; Zhang, Zailei; Ji, Yongjun; Zhan, Hanhui; Xiao, Fangxing; Wang, Dan; Liu, Bin; Su, Fabing

    2015-01-01

    Highlights: • CeO 2 -TiO 2 /SiO 2 composites were prepared via a facile co-precipitation method. • Introduction of SiO 2 support increases the dispersion of CeO 2 -TiO 2 . • CeO 2 -TiO 2 /SiO 2 exhibits an enhanced photocatalytic efficiency for phenol degradation. • Ce 3+ /Ce 4+ pair coexisting in CeO 2 improves electron–hole pairs separation efficiency. - Abstract: A series of CeO 2 -TiO 2 and CeO 2 -TiO 2 /SiO 2 composites were prepared with TiCl 4 and Ce (NO 3 ) 3 ·6H 2 O as precursors via a facile co-precipitation method. The obtained samples were characterized by various techniques such as X-ray diffraction (XRD), nitrogen adsorption (N 2 -BET), Fourier transformation infrared spectrum (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and UV–Vis spectroscopy measurements. The results indicated that TiO 2 doped with CeO 2 and supported on SiO 2 could reduce the crystallite size, inhibit the phase transformation, enhance the thermal stability, and effectively extend the spectral response from UV to visible range. When applied to the phenol photodegradation on a homemade batch reactor with an external cooling jacket, the CeO 2 -TiO 2 /SiO 2 catalysts exhibited significantly enhanced photodegradation efficiency in comparison with commercial Degussa P25 and CeO 2 -TiO 2 . The unique catalytic properties of CeO 2 -TiO 2 /SiO 2 were ascribed to improved electron–hole pairs separation efficiency and formation of more reactive oxygen species owing to the presence of Ce 3+ /Ce 4+ , as well as high dispersion of active component of CeO 2 -TiO 2 as a result of the introduction of SiO 2 support. Furthermore, the catalysts can be easily recovered from the reaction solution by centrifugation and reused for four cycles without significant loss of activity

  13. Analysis of the photo catalytic degradation of the 4-chloro phenol and endosulfan by gas chromatography; Analisis de la degradacion fotocatalitica del 4-clorofenol y endosulfan por cromatografia de gases

    Energy Technology Data Exchange (ETDEWEB)

    Pichardo S, E. [ININ, 52750 La Marquesa, Estado de Mexico (Mexico)

    2007-07-01

    The water and soil pollution by organic compounds of considerable toxicity, is every time more alarming. The phenols and organo chlorinated compounds are some of the pollutants of more environmental concern. The present work shows the degradation by heterogeneous photo catalysis of the 4-chloro phenol and endosulfan in watery solutions using a photo reactor at laboratory scale, under ultraviolet irradiation as energy source and titanium dioxide TiO{sub 2} Degussa P25 as catalyst. Solutions of both compounds at concentrations of 10, 20, 30 and 40 mg/L were used, analyzing the more important operation parameters with those that the maxima degradation levels were reached. The analyzed variables were catalyst concentration and irradiation time, the analytical techniques of ultraviolet-visible spectroscopy and gas chromatography were used as process control. By means of ultraviolet-visible spectroscopy it was settled down that starting from the quantitative analysis, the 4-chloro phenol presented bigger degradation at smaller concentrations. Under the operation conditions mentioned in this work, it was observed that the photo catalytic processes obey a first order behavior in the chemical kinetics being adjusted to the Langmuir-Hinshelwood model (L-H). With the purpose of checking the degradation of the same ones it was used the gas chromatography, which is an advanced technique for the process pursuit, auxiliary in the quantification and analysis of the photo catalytic degradation of the 4-chloro phenol and endosulfan. It was based on the development and validation of the analytical method, by means of which was proven that the method is good and reliable in the research environment. The results of the quantitative analysis by gas chromatography and ultraviolet-visible, derived of the photo catalytic degradation of the 4-chloro phenol, in the maximum time of study (180 minutes), using the concentrations of 10, 20, 30 and 40 mg/L was found, by gas chromatography, a

  14. Interactions of β-Conglycinin (7S with Different Phenolic Acids—Impact on Structural Characteristics and Proteolytic Degradation of Proteins

    Directory of Open Access Journals (Sweden)

    Jing Gan

    2016-10-01

    Full Text Available p-Coumalic acid (PCA, caffeic acid (CA, gallic acid (GA and chlorogenic acid (CGA are the major phenolic acids that co-exist with soy protein components in foodstuffs. Surprisingly, there are only a handful of reports that describe their interaction with β-Conglycinin (7S, a major soy protein. In this report, we investigated the interaction between phenolic acids and soy protein 7S and observed an interaction between each of these phenolic acids and soy protein 7S, which was carried out by binding. Further analysis revealed that the binding activity of the phenolic acids was structure dependent. Here, the binding affinity of CA and GA towards 7S was found to be stronger than that of PCA, because CA and GA have one more hydroxyl group. Interestingly, the binding of phenolic acids with soy protein 7S did not affect protein digestion by pepsin and trypsin. These findings aid our understanding of the relationship between different phenolic acids and proteins in complex food systems.

  15. Investigations into aerobic bacterial degradation of phenol compounds in consideration of ecological and physiological parameters; Untersuchungen zum aeroben Abbau phenolischer Verbindungen durch Bakterien unter Beruecksichtigung oekologisch und physiologisch relevanter Faktoren

    Energy Technology Data Exchange (ETDEWEB)

    Rittich, S.

    1992-07-01

    In a polluted soil of an abandoned gas works site, pure bacterial cultures were isolated which were able to degrade phenol, the three cresol isomers, and 2,3-, 2,4- and 3,4-xylenol. There were also mixed populations which degraded 2,5- and 3,5-xylenol. There were no bacteria in this soil which were able to degrade 2,6-xylenol. In spite of this, it was possible for the first time to decompose 2,6-xylenol using a mixed population of three different bacterial strains from other soils. One of these was a strain identified as Myeobacterium spec.SR18 which used 2,6-xylenol as its sole source of C and energy. (orig./EF). [Deutsch] Aus einem mit Schadstoffen kontaminierten Boden eines ehemaligen Gaswerkgelaeaendes konnten Reinkulturen isoliert werden, die in der Lage waren Phenol, die drei Kresolisomere und 2,3-, 2,4- und 3,4-Xylenol abzubauen. Ein 2,5- und 3,5-Xylenolabbau durch Mischpopulationen wurde ebenfalls beobachtet. Dagegen konnten aus diesem Boden keine 2,6-Xylenol-Abbauer gewonnen werden. Der bisher erst einmal beschriebene 2,6-Xylenolabbau gelang schliesslich mit einer weiteren, aus anderen verunreinigten Standorten angereicherten, Mischpopulation, die aus drei verschiedenen Bakterienstaemmen bestand. Darunter befand sich auch ein als Mycobacterium spec.SR18 identifizierter Stamm, der 2,6-Xylenol als alleinige C- und Energiequelle verwertet. (orig./EF).

  16. Bacterial removal of toxic phenols from an industrial effluent

    African Journals Online (AJOL)

    STORAGESEVER

    2008-07-04

    Jul 4, 2008 ... the ability of utilizing various chlorophenolic compounds and demonstrates its potentials of degrading high concentration of phenol in industrial effluents. Key words: Bioremediation, Pseudomonas fluorescens, industrial effluent, chlorophenols. INTRODUCTION. Chlorinated phenols are important chemicals ...

  17. Influence of ph and inoculum size on phenol utilization by bacterial ...

    African Journals Online (AJOL)

    The influence of pH and inoculum size on phenol utilization by bacterial isolates from oil refinery effluent was investigated. The substrate used for the assessment was phenol, which formed a model substrate for the experiment. Phenol was progressively degraded at pH range of 6.3 to 8.0. Maximum phenol degradation by ...

  18. Enhanced anaerobic biological treatment of phenolic wastewaters

    Energy Technology Data Exchange (ETDEWEB)

    Kindzierski, W.B.

    1989-01-01

    The combined treatment requirements for a high strength phenolic wastewater were examined in batch and semicontinuous anaerobic methanogenic bioassays. Solvent extraction pretreatment and in-situ addition of activated carbon during anaerobic treatment were effective in removing phenol from a coal liquefaction wastewater from the H-coal process. The selective pH adjustment of high strength phenolic wastewater followed by diisopropyl ether extraction reduced the phenolic concentration to non-inhibitory levels, and removed non-phenolic inhibitory compounds. The weakly acid nature of phenol and substituted phenols allows for their selective removal by solvent extraction. Anaerobic bacteria were able to degrade phenol in the solvent extracted wastwater, however, the bacteria exhibited instability under semicontinuous feeding conditions. The addition of activated carbon to the stressed phenol-degrading cultures improved their ability to remove phenol from solution. Further investigation into the role activated carbon performed during anaerobic phenol treatment demonstrated its importance as a biological support, in addition to providing adsorptive capacity for organic (including inhibitory) compounds. The similar study of other support materials (ion exchange resins) which did not possess an adsorptive capacity for organic compounds supported these findings. Excellent agreement was demonstrated among physical evaluation methods, performance bioassays, radiolabelled cell adsorption studies, and scanning electron microscopy observations in judging the value of the materials as biological supports.

  19. Enhanced photocatalytic degradation of aqueous phenol and Cr(VI) over visible-light-driven Tb{sub x}O{sub y} loaded TiO{sub 2}-oriented nanosheets

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Dingze; Yang, Minchen; Fang, Pengfei, E-mail: fangpf@whu.edu.cn; Li, Chunhe; Jiang, Lulu

    2017-03-31

    Highlights: • Tb-TNSs with high stability and regeneration behavior were prepared by one-pot method. • Loaded Tb{sub x}O{sub y} nanoparticles lead to obvious increase of the Ti{sup 3+} ions content. • Loaded Tb{sub x}O{sub y} results in the changes in the structure of the TNSs and red shift. • Loaded Tb{sub x}O{sub y} can effectively trap electrons to enhance the separation of charges. • Tb-TNSs exhibit excellent synergistic photocatalytic activities for Cr(VI) and phenol. - Abstract: A visible-light-driven Tb{sub x}O{sub y} loaded TiO{sub 2}-oriented nanosheets (Tb-TNSs) of 3.6 nm thick and specific surface area of 240–350 m{sup 2}/g provided with highly dispersed Tb{sub x}O{sub y} nanoparticles of 1–2 nm over the surfaces were synthesized using a one-pot hydrothermal route. Loaded Tb{sub x}O{sub y} nanoparticles influenced morphology, structure, and optical properties of the TNSs. The XPS results showed that Tb{sup 3+} and Tb{sup 4+} co-exist in Tb-TNSs, and loaded Tb{sub x}O{sub y} resulted in changes in binding energies of Ti and O. The amount of Ti{sup 3+} increased gradually with the amount of loaded Tb{sub x}O{sub y} nanoparticles. FL and surface photocurrent spectra results indicated that an appropriate amount of Tb{sub x}O{sub y} (≤1.0 at.%) loading can effectively improve the separation efficiency of charge carriers. The visible-light-driven photocatalysis could be measured by the removal of phenol or dichromate separately along with synergistic degradation in phenol-Cr(VI) coexistence system. The optimum photocatalytic activity was obtained at Tb/Ti = 1.0 at.% under degradation of aqueous phenol or Cr(VI) solution. Besides, the desorbed Tb-TNSs could be easily regenerated by remedying the damaged structure and reused with excellent performance. High regeneration and stability of photocatalysts were confirmed by seven cyclic tests. An alternant mechanism for the enhanced visible-light-driven photocatalytic activity was also considered.

  20. Sorption of phenol and phenol derivatives in hydrotalcite

    International Nuclear Information System (INIS)

    Avina G, E.I.

    2002-01-01

    One of the main problems in Mexico and in the World is the waste water pollution of a great variety of industrial processes by organic compounds. Among those ones the phenol compounds which are highly toxic, refractories (to the chemical degradation) and poorly biodegradable. This is due in a large extent to the problem created by the accelerated increase in the environmental pollution in the cities and industrial centers. The phenol compounds are used in a great variety of industries such as the production of resins, plasticizers, antioxidants, pesticides, colourings, disinfectants, etc. These phenol compounds are specially harmful, since they have repercussions on the flora of plants of biological treatment of water affecting its operation. The main objective of this work is to evaluate the capacities of phenol detention and its derivatives in an hydrotalcite type compound and diminishing with it the presence in water, in this case, of solutions prepared in the laboratory. In order to analyse this elimination process was used a methodology based in the carrying out in batch experiments and in the elaboration of a sorption isotherm. It is worth pointing out that this work was realized at laboratory scale, at relatively high phenol concentration ratio. With the obtained results when the sorption properties are evaluated the calcined hydrotalcite (HTC) for detaining phenol and p-chloro phenol it was observed that it is detained greater quantity of p-chloro phenol than phenol in the HTC. The detention of these phenol compounds in the HTC is due to the memory effect by the hydrotalcite regeneration starting from the oxides which are formed by the burning material. (Author)

  1. PHENOLIC ACIDS AND LIGNINS IN THE LYCOPODIALES,

    Science.gov (United States)

    ethanolysis or alkaline oxidation of their extracted wood-meals. p-Hydroxybenzoic, vanillic, p-coumaric and ferulic acids were identified in phenolic acid ...Twenty-one species and varieties of Lycopodium have been examined for phenolic acids and for phenolic aldehydes, ketones and acids obtained on...found to yield syringic acid in the ethanol-soluble fraction and on degradation of lignin whereas species included in the genera Huperzia and Lepidotis

  2. Anaerobic methanogenic treatment of phenolic wastewaters

    Energy Technology Data Exchange (ETDEWEB)

    Fedorak, P.M.; Hrudey, S.E.

    1982-09-01

    Batch culture experiments using domestic anaerobic sewage sludge were carried out with a variety of aromatic compounds to determine whether methanogenic fermentations of these substrates could be established. Of the 11 phenolics tested, only phenol and p-cresol were fermented to methane. The acclimation time for the degradation of these two substrates increased as their concentrations increased. In batch cultures, phenol or p-cresol were not degraded when their concentrations were greater than 500 and 400 mg/l respectively, although at higher concentrations, the methanogenic fermentations of non-phenolic substrates were not inhibited. Thus the phenolic-degrading bacteria are more susceptible to inhibition by the toxic substrates than are the methane bacteria. Four dimethylphenol isomers inhibited methane fermentation at 500 but not at 300 mg/l. Maximum degradation rates for phenol and p-cresol were found to be 42 and 52 mg/l/d respectively. Draw-and-feed cultures were established on these substrates, and the phenol-degrading culture showed a substrate removal efficiency of over 99.8%. The reactor, operated with a hydraulic retention time of 25 d and a solids retention time approaching infinity, received a nutrient solution containing 500 mg/l phenol. Preliminary batch cultures inoculated with oil sands tailings pond sludge indicate that microorganisms may exist therein, which are capable of anaerobically degrading o- and m-cresol, 2,5- and 3,5-dimethylphenol, and 3,4-dihydroxytoluene. Overall, these findings indicate that the anaerobic methanogenic degradation of phenolic wastewaters is biochemically feasible. 110 refs., 18 figs., 11 tabs.

  3. NiWO4-ZnO-NRGO ternary nanocomposite as an efficient photocatalyst for degradation of methylene blue and reduction of 4-nitro phenol

    Science.gov (United States)

    Sadiq, M. Mohamed Jaffer; Shenoy, U. Sandhya; Bhat, D. Krishna

    2017-10-01

    A novel NiWO4-ZnO-NRGO ternary nanocomposite has been efficiently synthesized by decorating nitrogen doped reduced graphene oxide (NRGO) with zinc oxide and nickel tungstate nanoparticles via a facile microwave irradiation technique and its capability to catalyze photodegradation of methylene blue (MB) dye in aqueous solution and reduction of 4-nitro phenol (4-NP) to 4-amino phenol (4-AP) using sodium borohydride was explored. The as-synthesized nanocomposite was characterized by X-ray diffraction (XRD), Raman spectroscopy, Brunauer-Emmett-Teller (BET) analysis, energy dispersive X-ray (EDX) analysis, field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), photoluminescence (PL) spectroscopy and diffuse reflectance spectroscopy (DRS) techniques. The photocatalytic activity of the as-synthesized nanocomposite estimated through the photodegradation of MB under visible light irradiation showed 9 times improvement over pure NiWO4. It also showed excellent catalytic activity in reduction of 4-NP to 4-AP. The material also showed excellent stability and reusability. The entire study revealed that the novel NiWO4-ZnO-NRGO ternary nanocomposite can act as a promising bifunctional photocatalyst for environmental remediation and industrial application.

  4. Introducing Aviary

    CERN Document Server

    Peutz, Mike

    2010-01-01

    The world is changing. Where before you needed to purchase and install big and expensive programs on your computer in order to create stunning images, you can now do it all online for free using Aviary. Aviary is an online collection of applications that enable you to upload and modify your own photographs and images, and create new imagery from scratch. It includes a powerful photo-manipulation tool called Phoenix, a vector-drawing application called Raven, an effects suite for creating eye-watering image effects called Peacock, and much more. Introducing Aviary takes you through all of these

  5. Introducing Mudbox

    CERN Document Server

    Kermanikian, Ara

    2010-01-01

    One of the first books on Autodesk's new Mudbox 3D modeling and sculpting tool!. Autodesk's Mudbox was used to create photorealistic creatures for The Dark Knight , The Mist , and others films. Now you can join the crowd interested in learning this exciting new digital modeling and sculpting tool with this complete guide. Get up to speed on all of Mudbox's features and functions, learn how sculpt and paint, and master the art of using effective workflows to make it all go easier.: Introduces Autodesk's Mudbox, an exciting 3D modeling and sculpting tool that enables you to create photorealistic

  6. Individual or synchronous biodegradation of di-n-butyl phthalate and phenol by Rhodococcus ruber strain DP-2

    Energy Technology Data Exchange (ETDEWEB)

    He, Zhixing; Niu, Chengzhen; Lu, Zhenmei, E-mail: lzhenmei@zju.edu.cn

    2014-05-01

    Highlights: • A Rhodococcus ruber strain degraded DBP and phenol. • Degradation kinetics of DBP or phenol fit modified first-order models. • Degradation interaction between DBP and phenol was studied by strain DP-2. • The degradation genes transcriptional were quantified by RT-qPCR. - Abstract: The bacterial strain DP-2, identified as Rhodococcus ruber, is able to effectively degrade di-n-butyl phthalate (DBP) and phenol. Degradation kinetics of DBP and phenol at different initial concentrations revealed DBP and phenol degradation to fit modified first-order models. The half-life of DBP degradation ranged from 15.81 to 27.75 h and phenol degradation from 14.52 to 45.52 h under the initial concentrations of 600–1200 mg/L. When strain DP-2 was cultured with a mixture of DBP (800 mg/L) and phenol (700 mg/L), DBP degradation rate was found to be only slightly influenced; however, phthalic acid (PA) accumulated, and phenol degradation was clearly inhibited during synchronous degradation. Transcriptional levels of degradation genes, phenol hydroxylase (pheu) and phthalate 3,4-dioxygenase (pht), decreased significantly more during synchronous degradation than during individual degradation. Quantitative estimation of individual or synchronous degradation kinetics is essential to manage mixed hazardous compounds through biodegradation in industrial waste disposal.

  7. Continuous phenol removal using Nocardia hydrocarbonoxydans in ...

    African Journals Online (AJOL)

    Shock load studies are essential to investigate the suitability of biocontactors in degradation of pollutants. In the present work, the degradation of phenol by immobilized Nocardia hydrocarbonoxydans in a spouted bed contactor was conducted. Granular activated carbon (GAC) and polymer beads were tested for the ...

  8. Tungsten-doped TiO2/reduced Graphene Oxide nano-composite photocatalyst for degradation of phenol: A system to reduce surface and bulk electron-hole recombination.

    Science.gov (United States)

    Yadav, Manisha; Yadav, Asha; Fernandes, Rohan; Popat, Yaksh; Orlandi, Michele; Dashora, Alpa; Kothari, D C; Miotello, Antonio; Ahuja, B L; Patel, Nainesh

    2017-12-01

    Recombination of photogenerated charges is the main factor affecting the photocatalytic activity of TiO 2 . Here, we report a combined strategy of suppressing both the bulk as well as the surface recombination processes by doping TiO 2 with tungsten and forming a nanocomposite with reduced graphene oxide (rGO), respectively. Sol-gel method was used to dope and optimize the concentration of W in TiO 2 powder. UV-Vis, XPS, PL and time resolved PL spectra along with DFT calculations indicate that W 6+ in TiO 2 lattice creates an impurity level just below the conduction band of TiO 2 to act as a trapping site of electrons, which causes to improve the lifetime of the photo-generated charges. Maximum reduction in the PL intensity and the improvement in charge carrier lifetime was observed for TiO 2 doped with 1 at.% W (1W-TiO 2 ), which also displayed the highest photo-activity for the degradation of p-nitro phenol pollutant in water. Tuning of rGO/TiO 2 ratio (weight) disclosed that the highest activity can be achieved with the composite formed by taking equal amounts of TiO 2 and rGO (1:1), in which the strong interaction between TiO 2 and rGO causes an effective charge transfer via bonds formed near the interface as indicated by XPS. Both these optimized concentrations were utilized to form the composite rGO/1W-TiO 2 , which showed the highest activity in photo-degradation of p-nitro phenol (87%) as compared to rGO/TiO 2 (42%), 1W-TiO 2 (62%) and pure TiO 2 (29%) in 180 min. XPS and PL results revealed that in the present nanocomposite, tungsten species traps the excited electron to reduce the interband recombination in the bulk, while the interaction between TiO 2 and rGO creates a channel for fast transfer of excited electrons towards the latter before being recombined on the surface defect sites. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Sunlight-assisted Fenton reaction catalyzed by gold supported on diamond nanoparticles as pretreatment for biological degradation of aqueous phenol solutions.

    Science.gov (United States)

    Navalon, Sergio; Martin, Roberto; Alvaro, Mercedes; Garcia, Hermenegildo

    2011-05-23

    Gold nanoparticles supported on Fenton-treated diamond nanoparticles (Au/DNPs) have been reported as one of the most efficient solid catalysts effecting the Fenton reaction, achieving a turnover number (TON) as high as 321,000. However, at room temperature the main limitation for the catalytic activity of Au/DNPs is the pH of the solution, which should be less than 5. In this paper, we report that exposure of Au/DNPs to sunlight enhances the catalytic activity of Au/DNPs up to the point that it can promote the Fenton reaction at room temperature even at slightly basic pH values. Also, in addition to performing a deep Fenton treatment and considering that the excess of H(2)O(2) used in the process should be minimized, we have achieved in our study, using a mild Fenton reaction promoted by Au/DNPs under sunlight irradiation, an optimum in the biodegradability, a minimum in the ecotoxicity, and no toxicity for the Vibrio fischeri test. The results have shown that, by using an H(2)O(2) -to-phenol molar ratio of 5.5 or higher, it is possible to achieve a high biodegradability as well as a complete lack of ecotoxicity and of Vibrio fischeri toxicity. The stability of Au/DNPs was confirmed by analyzing the gold leached to the solution and by performing four consecutive reuses of the catalyst with initial pH values ranging from 4 to 8. It was observed that, after finishing the reaction and exhaustive washings with basic aqueous solutions, the initial reaction rate of the used catalyst is recovered to the value exhibited by the fresh solid. Overall, our study shows that the synergism between catalysis and photocatalysis can overcome the limitations found for dark catalytic reactions and that the reaction parameters can be optimized to effect mild Fenton reactions aimed at increasing biodegradability in biorecalcitrant waste waters. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Cometabolic degradation of trichloroethylene by Burkholderia cepacia G4 with poplar leaf homogenate.

    Science.gov (United States)

    Kang, Jun Won; Doty, Sharon Lafferty

    2014-07-01

    Trichloroethylene (TCE), a chlorinated organic solvent, is one of the most common and widespread groundwater contaminants worldwide. Among the group of TCE-degrading aerobic bacteria, Burkholderia cepacia G4 is the best-known representative. This strain requires the addition of specific substrates, including toluene, phenol, and benzene, to induce the enzymes to degrade TCE. However, the substrates are toxic and introducing them into the soil can result in secondary contamination. In this study, poplar leaf homogenate containing natural phenolic compounds was tested for the ability to induce the growth of and TCE degradation by B. cepacia G4. The results showed that the G4 strain could grow and degrade TCE well with the addition of phytochemicals. The poplar leaf homogenate also functioned as an inducer of the toluene-ortho-monooxygenase (TOM) gene in B. cepacia G4.

  11. Photodegradation of phenol on Y2O3 surface

    International Nuclear Information System (INIS)

    Karunakaran, C.; Dhanalakshmi, R.; Anilkumar, P.

    2009-01-01

    Under UV light, phenol degrades on the surface of Y 2 O 3 , an insulator, and the degradation follows first-order kinetics, depends linearly on the light intensity and slows down with pH. The efficiency of degradation is higher with UV-C light than with UV-A light. While particulate anatase TiO 2 , ZnO, ZnS, Fe 2 O 3 , CuO, CdO, and Nb 2 O 5 individually photodegrade phenol, each semiconductor shows synergism when present along with Y 2 O 3 , indicating electron-transfer from phenol adsorbed on Y 2 O 3 to the illuminated semiconductors.

  12. Biodegradation of Phenol by Bacteria Strain Acinetobacter Calcoaceticus PA Isolated from Phenolic Wastewater

    Directory of Open Access Journals (Sweden)

    Zhenghui Liu

    2016-03-01

    Full Text Available A phenol-degrading bacterium strain PA was successfully isolated from the effluent of petrochemical wastewater. Based on its morphological, physiological and biochemical characteristics, the strain PA was characterized as a Gram-negative, strictly aerobic, nonmotile and short rod-shaped bacterium that utilizes phenol as a sole carbon and energy source. 16S rDNA sequence analysis revealed that this strain is affiliated to Acinetobacter calcoaceticus in the group of Gammaproteobacteria. The strain was efficient in removing 91.6% of the initial 800 mg∙L−1 phenol within 48 h, and had a tolerance of phenol concentration as high as 1700 mg∙L−1. These results indicated that A. calcoaceticus possesses a promising potential in treating phenolic wastewater.

  13. Biodegradation of Phenol by Bacteria Strain Acinetobacter Calcoaceticus PA Isolated from Phenolic Wastewater.

    Science.gov (United States)

    Liu, Zhenghui; Xie, Wenyu; Li, Dehao; Peng, Yang; Li, Zesheng; Liu, Shusi

    2016-03-09

    A phenol-degrading bacterium strain PA was successfully isolated from the effluent of petrochemical wastewater. Based on its morphological, physiological and biochemical characteristics, the strain PA was characterized as a Gram-negative, strictly aerobic, nonmotile and short rod-shaped bacterium that utilizes phenol as a sole carbon and energy source. 16S rDNA sequence analysis revealed that this strain is affiliated to Acinetobacter calcoaceticus in the group of Gammaproteobacteria. The strain was efficient in removing 91.6% of the initial 800 mg ∙ L(-1) phenol within 48 h, and had a tolerance of phenol concentration as high as 1700 mg ∙ L(-1). These results indicated that A. calcoaceticus possesses a promising potential in treating phenolic wastewater.

  14. Bacterial removal of toxic phenols from an industrial effluent | Lin ...

    African Journals Online (AJOL)

    isolate, identified as Pseudomonas fluorescens, was obtained using the enrichment process with 2,4,6-trichlorophenol (2,4,6-TCP) as a sole carbon source. This isolate was found to be able to degrade various highly chlorinated phenolic compounds such as pentachlorophenol, 2,4,5-TCP, 2,4,6-TCP as well as phenol, ...

  15. Development of methodology for the determination of carbon isotope ratios using gas chromatography/combustion/isotope ratio mass spectrometry and applications in the biodegradation of phenolic brominated flame retardants and their degradation products.

    Science.gov (United States)

    Xiong, Jukun; Li, Guiying; An, Taicheng

    2015-01-15

    Compound-specific stable carbon isotope analysis of phenolic brominated flame retardants (BFRs) and bisphenol A (BPA) has proven informative to discriminate their source and fate apportionment in the environment. However, because these compounds contain highly polar functional groups and exist as complex mixtures in environment matrices, derivatization is a necessary step, which adds additional non-analyte carbon atoms for analyses and may alter the original stable carbon isotope ratio. It is, therefore, imperative to gain an insight into the relationship between the δ(13) C values of the BFRs and BPA derivatives and those of underivatized BFRs and BPA. The δ(13) C values of BFRs and BPA N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) derivatives were measured by gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS). The δ(13) C values of the BSTFA reagent and the standard underivatized BFRs and BPA were determined using elemental analyzer/isotope ratio mass spectrometry (EA/IRMS). The experimentally obtained δ(13) C values for BFRs and BPA derivatives were then compared with the theoretically calculated values. The derivatization process introduces no isotopic fractionation for BFRs and BPA (the average difference between the theoretically calculated and experimentally obtained δ(13) C values was 0.06 ± 0.15‰, within the precision limits of the GC/C/IRMS measurements). Therefore, the δ(13) C values for the original underivatized BFRs and BPA were computed through a mass balance equation. This work offers a novel tool to research the biotic or abiotic transformation processes of BFRs and BPA in the environment and will offer a perspective for the identification of the environmental source and fate of these organic compounds. Copyright © 2014 John Wiley & Sons, Ltd.

  16. Solistatinol, a novel phenolic compactin analogue from Penicillium solitum

    DEFF Research Database (Denmark)

    Larsen, Thomas Ostenfeld; Lange, Lene; Schnorr, Kirk

    2007-01-01

    Solistatinol, a novel phenolic compactin analogue, has been isolated from Penicillium solitum using a UV-guided strategy. The structure and relative stereochemistry were determined by NMR spectroscopy and mass spectrometry. The absolute stereochemistry was determined by chemical degradation...

  17. Integrated photocatalytic-biological reactor for accelerated phenol mineralization.

    Science.gov (United States)

    Zhang, Yongming; Wang, Lei; Rittmann, Bruce E

    2010-05-01

    An integrated photocatalytic-biological reactor (IPBR) was developed for accelerated phenol degradation and mineralization. In the IPBR, photodegradation and biodegradation occurred simultaneously, but in two separated zones: a piece of mat-glass plate coated with TiO(2) film and illuminated by UV light was connected by internal circulation to a honeycomb ceramic that was the biofilm carrier for biodegradation. This arrangement was designed to give intimate coupling of photocatalysis and biodegradation. Phenol degradation was investigated by following three protocols: photocatlysis with TiO(2) film under ultraviolet light, but no biofilm (photodegradation); biofilm biodegradation with no UV light (biodegradation); and simultaneous photodegradation and biodegradation (intimately coupled photobiodegradation). Photodegradation alone could partly degrade phenol, but was not able to achieve significant mineralization, even with an HRT of 10 h. Biodegradation alone could completely degrade phenol, but it did not mineralize the COD by more than 74%. Photobiodegradation allowed continuous rapid degradation of phenol, but it also led to more complete mineralization of phenol (up to 92%) than the other protocols. The results demonstrate that intimate coupling was achieved by protecting the biofilm from UV and free-radical inhibition. With phenol as the target compound, the main advantage of intimate coupling in the IPBR was increased mineralization, presumably because photocatalysis made soluble microbial products more rapidly biodegradable.

  18. Antioxidant degradation kinetics in apples.

    Science.gov (United States)

    Arora, Bindvi; Sethi, Shruti; Joshi, Alka; Sagar, V R; Sharma, R R

    2018-04-01

    The effect of shelf storage under ambient conditions of cut apple dices on degradation of bioactive compounds such ascorbic acid, total phenols, antioxidant activity (% DPPH inhibition) and PPO activity were investigated. The results indicated that antioxidant activity declined significantly over 80 min storage of diced apples at ambient temperature. Similar trend was observed for ascorbic acid, total phenols and PPO activity. Ascorbic acid, total phenols and antioxidant activity degradation followed first-order kinetics where the rate constant (k) was found to be in range for all the thirteen cultivars, though initial ascorbic acid and phenol content varied in different apple cultivars. The reaction rate constant (k) for first order degradation ranged from 1.16 to 1.97, 0.89 to 1.29 and 0.37 to 1.54 for antioxidant activity, total phenols and ascorbic acid, respectively. This explains that antioxidant activity degrades at higher rate than total phenols and ascorbic acid, which also corroborates that antioxidant activity is affected by both total phenols and ascorbic acid content. In general, total antioxidant activity for apple dices kept for 80 min under ambient conditions exhibited lower values as compared to control.

  19. Biodegradation of phenol by free and encapsulated cells of a new ...

    African Journals Online (AJOL)

    Encapsulated filamentous fungus Aspergillus sp. LEBM2 showed a promising application in bioaugmentation processes, reaching maximum phenol degradation rate of 7.71 ± 0.21 mg/l.h for an initial phenol concentration of 500 mg/l. Key words: Bioremediation, bioaugmentation, immobilization, phenol, filamentous fungi.

  20. Enhancing charge storage of conjugated polymer electrodes with phenolic acids

    Science.gov (United States)

    Wagner, Michal; Rębiś, Tomasz; Inganäs, Olle

    2016-01-01

    We here present studies of electrochemical doping of poly(1-aminoanthraquinone) (PAAQ) films with three structurally different phenolic acids. The examined phenolic acids (sinapic, ferulic and syringic acid) were selected due to their resemblance to redox active groups, which can be found in lignin. The outstanding electrochemical stability of PAAQ films synthesized for this work enabled extensive cycling of phenolic acid-doped PAAQ films. Potentiodynamic and charge-discharge studies revealed that phenolic acid-doped PAAQ films exhibited enhanced capacitance in comparison to undoped PAAQ films, together with appearance of redox activity characteristics specific for each dopant. Electrochemical kinetic studies performed on microelectrodes affirmed the fast electron transfer for hydroquinone-to-quinone reactions with these phenolic compounds. These results imply the potential application of phenolic acids in cheap and degradable energy storage devices.

  1. Feasibility and application of liquid-liquid extraction combined with gas chromatography-mass spectrometry for the analysis of phenolic acids from grape polyphenols degraded by human faecal microbiota.

    Science.gov (United States)

    Muñoz-González, C; Moreno-Arribas, M V; Rodríguez-Bencomo, J J; Cueva, C; Martín Álvarez, P J; Bartolomé, B; Pozo-Bayón, M A

    2012-07-15

    In this study the feasibility of a LLE-GC-EI-MS method for the analysis of 43 phenolic acids belonging to different chemical structure families which have been described in the literature as microbial-derived metabolites after consumption of dietary polyphenols was proved. In addition, the method was applied for the characterisation of phenolic metabolites resulting from the incubation, in anaerobic conditions, of a commercial grape seed extract (GSE) and their corresponding flavan-3-ol monomeric (GSE-M) and oligomeric (GSE-O) fractions with human faeces from healthy volunteers (n=3). The method showed average values of repeatability and reproducibility of 5.0% and 6.3%, respectively, adequate and low detection (1.8-30.8 μg L(-1)) and quantification limits (6.0-102.8 μg L(-1)) and good recovery values (95%, as average value). A total of 27 phenolic acids were identified in the faecal solutions after incubation with the grape seed extracts. In general, faecal samples incubated with GSE and GSE-M (monomeric fraction) yield a higher formation of phenolic acids compared to the samples incubated with the oligomer fraction (GSE-O). Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Phenol Removal by a Novel Non-Photo-Dependent Semiconductor Catalyst in a Pilot-Scaled Study: Effects of Initial Phenol Concentration, Light, and Catalyst Loading

    Directory of Open Access Journals (Sweden)

    Xiao Chen

    2014-01-01

    Full Text Available A novel non-photo-dependent semiconductor catalyst (CT was employed to degrade phenol in the present pilot-scaled study. Effect of operational parameters such as phenol initial concentration, light area, and catalyst loading on phenol degradation, was compared between CT catalyst and the conventional photocatalyst titanium dioxide. CT catalyst excelled titanium dioxide in treating and mineralizing low-level phenol, under both mild UV radiation and thunder conditions of nonphoton. The result suggested that CT catalyst could be applied in circumstances when light is not easily accessible in pollutant-carrying media (e.g., particles, cloudy water, and colored water.

  3. Phenols in anaerobic digestion processes and inhibition of ammonia oxidising bacteria (AOB) in soil

    International Nuclear Information System (INIS)

    Leven, Lotta; Nyberg, Karin; Korkea-aho, Lena; Schnuerer, Anna

    2006-01-01

    This study focuses on the presence of phenols in digestate from seven Swedish large-scale anaerobic digestion processes and their impact on the activity of ammonia oxidising bacteria (AOB) in soil. In addition, the importance of feedstock composition and phenol degradation capacity for the occurrence of phenols in the digestate was investigated in the same processes. The results revealed that the content of phenols in the digestate was related to the inhibition of the activity of AOB in soil (EC 5 = 26 μg phenols g -1 d.w. soil). In addition, five pure phenols (phenol, o-, p-, m-cresol and 4-ethylphenol) inhibited the AOB to a similar extent (EC 5 = 43-110 μg g -1 d.w. soil). The phenol content in the digestate was mainly dependent on the composition of the feedstock, but also to some extent by the degradation capacity in the anaerobic digestion process. Swine manure in the feedstock resulted in digestate containing higher amounts of phenols than digestate from reactors with less or no swine manure in the feedstock. The degradation capacity of phenol and p-cresol was studied in diluted small-scale batch cultures and revealed that anaerobic digestion at mesophilic temperatures generally exhibited a higher degradation capacity compared to digestion at thermophilic temperature. Although phenol, p-cresol and 4-ethylphenol were quickly degraded in soil, the phenols added with the digestate constitute an environmental risk according to the guideline values for contaminated soils set by the Swedish Environmental Protection Agency. In conclusion, the management of anaerobic digestion processes is of decisive importance for the production of digestate with low amounts of phenols, and thereby little risks for negative effects of the phenols on the soil ecosystem

  4. Enzymatic oxidative transformation of phenols by Trametes trogii laccases.

    Science.gov (United States)

    Chakroun, Hanen; Bouaziz, Mohamed; Dhouib, Abdelhafidh; Sayadi, Sami

    2012-09-01

    The removal of toxic phenolic compounds from industrial wastewater is an important issue to be addressed. Their presence in water and soil has become a great environmental concern, and effective methods for their removal need to be addressed. The feasibility of applying laccases for the degradation of phenolic compounds has received increasing attention. In the present work, the transformation of five phenolic compounds (catechol, hydroxytyrosol, tyrosol, guaiacol and p-coumaric acid), the main constituents of a typical wastewater derived from an olive oil factory, by Trametes trogii laccases was studied at concentrations ranging between 0.2 and 1.6 mM. High-performance liquid chromatography analysis showed high degradation rates of phenolic compounds by T trogii laccases. Independently of the used concentration, a complete transformation of guaiacol, p-coumaric acid, hydroxytyrosol and tyrosol occurred after 1 h of incubation. The transformation of catechol depends on its initial concentration. The liquid chromatography-mass spectrometry analysis showed that laccases catalysed transformation of p-coumaric acid and tyrosol, resulting in the formation of phenolic dimers. No reduction of enzyme activity has been observed during the oxidation of all phenolic compounds. These results suggest that the studied laccases were capable of efficiently removing phenolic compounds, as well as catalysing the production of novel phenolic dimers.

  5. Catalytic Ozonation of Phenolic Wastewater: Identification and Toxicity of Intermediates

    Directory of Open Access Journals (Sweden)

    Mahdi Farzadkia

    2014-01-01

    Full Text Available A new strategy in catalytic ozonation removal method for degradation and detoxification of phenol from industrial wastewater was investigated. Magnetic carbon nanocomposite, as a novel catalyst, was synthesized and then used in the catalytic ozonation process (COP and the effects of operational conditions such as initial pH, reaction time, and initial concentration of phenol on the degradation efficiency and the toxicity assay have been investigated. The results showed that the highest catalytic potential was achieved at optimal neutral pH and the removal efficiency of phenol and COD is 98.5% and 69.8%, respectively. First-order modeling demonstrated that the reactions were dependent on the initial concentration of phenol, with kinetic constants varying from 0.038 min−1  ([phenol]o = 1500 mg/L to 1.273 min−1 ([phenol]o = 50 mg/L. Bioassay analysis showed that phenol was highly toxic to Daphnia magna (LC50 96 h=5.6 mg/L. Comparison of toxicity units (TU of row wastewater (36.01 and the treated effluent showed that TU value, after slightly increasing in the first steps of ozonation for construction of more toxic intermediates, severely reduced at the end of reaction (2.23. Thus, COP was able to effectively remove the toxicity of intermediates which were formed during the chemical oxidation of phenolic wastewaters.

  6. Methylene blue and 4-chloro phenol degradation by photo catalysis with ultraviolet light, using TiO{sub 2} as catalyst; Degradacion de azul de metileno y 4-clorofenol por fotocatalisis con luz ultravioleta, utilizando TiO{sub 2} como catalizador

    Energy Technology Data Exchange (ETDEWEB)

    Martinez H, A.

    2010-07-01

    Within the decontamination and remediation processes of the contaminated waters, as the refining or tertiary processes are the Advanced Oxidation Technologies. Among this technology is the heterogeneous photo catalysis, which is the object of this work to de grate 4-chloro phenol and methylene blue, using as semiconductor commercial titanium dioxide (TiO{sub 2}). On the degradation the combination is exposed in the use of TiO{sub 2} under gamma irradiation of {sup 60}Co at different doses 400, 500, 800, 1000 and 1500 kGy. The organic compounds degradation was determined and the results show that to more radiation dose, the material is modified in such way that shows a major absorption of the organic compound, in the same way it is determined that to more dose which undergoes the TiO{sub 2} generally a major degradation is observed, but also it is has to give a more time of previous stabilization, for that the degradation is observed of better way. (Author)

  7. Phenolation of vegetable oils

    Directory of Open Access Journals (Sweden)

    ZORAN S. PETROVIĆ

    2011-04-01

    Full Text Available Novel bio-based compounds containing phenols suitable for the syn­thesis of polyurethanes were prepared. The direct alkylation of phenols with different vegetable oils in the presence of superacids (HBF4, triflic acid as ca­talysts was studied. The reaction kinetics was followed by monitoring the de­crease of the double bond content (iodine value with time. In order to under­stand the mechanism of the reaction, phenol was alkylated with model com­pounds. The model compounds containing one internal double bond were 9-oc­tadecene and methyl oleate and those with three double bonds were triolein and high oleic safflower oil (82 % oleic acid. It was shown that the best structures for phenol alkylation are fatty acids with only one double bond (oleic acid. Fatty acids with two double bonds (linoleic acid and three double bonds (lino­lenic acid lead to polymerized oils by a Diels–Alder reaction, and to a lesser extent to phenol alkylated products. The reaction product of direct alkylation of phenol with vegetable oils is a complex mixture of phenol alkylated with poly­merized oil (30–60 %, phenyl esters formed by transesterification of phenol with triglyceride ester bonds (<10 % and unreacted oil (30 %. The phenolated vegetable oils are new aromatic–aliphatic bio-based raw materials suitable for the preparation of polyols (by propoxylation, ethoxylation, Mannich reactions for the preparation of polyurethanes, as intermediates for phenolic resins or as bio-based antioxidants.

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

    Science.gov (United States)

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

    2003-01-01

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

  9. Anaerobic Benzene Oxidation via Phenol in Geobacter metallireducens

    Science.gov (United States)

    Tremblay, Pier-Luc; Chaurasia, Akhilesh Kumar; Smith, Jessica A.; Bain, Timothy S.; Lovley, Derek R.

    2013-01-01

    Anaerobic activation of benzene is expected to represent a novel biochemistry of environmental significance. Therefore, benzene metabolism was investigated in Geobacter metallireducens, the only genetically tractable organism known to anaerobically degrade benzene. Trace amounts (benzene to carbon dioxide with the reduction of Fe(III). Phenol was not detected in cell-free controls or in Fe(II)- and benzene-containing cultures of Geobacter sulfurreducens, a Geobacter species that cannot metabolize benzene. The phenol produced in G. metallireducens cultures was labeled with 18O during growth in H218O, as expected for anaerobic conversion of benzene to phenol. Analysis of whole-genome gene expression patterns indicated that genes for phenol metabolism were upregulated during growth on benzene but that genes for benzoate or toluene metabolism were not, further suggesting that phenol was an intermediate in benzene metabolism. Deletion of the genes for PpsA or PpcB, subunits of two enzymes specifically required for the metabolism of phenol, removed the capacity for benzene metabolism. These results demonstrate that benzene hydroxylation to phenol is an alternative to carboxylation for anaerobic benzene activation and suggest that this may be an important metabolic route for benzene removal in petroleum-contaminated groundwaters, in which Geobacter species are considered to play an important role in anaerobic benzene degradation. PMID:24096430

  10. Optimization of the biodegradation of phenol in a RDS; Optimizacion de la biodegradacion de fenol en un reactor discontinuo secuencial

    Energy Technology Data Exchange (ETDEWEB)

    Rancano, A.

    2007-07-01

    In this work the ideal conditions have been studied for the operation of a RDS to take to end the biological degradation of phenol. the results have shown that to minimize the time needed in the degradation the water volume that has to get in every cycle of operation is a function of the concentration of phenol in the nourishment, diminishing this volume on having increased the concentration, to avoid this way the presence of high concentrations of phenol inside the biological reactor, which would provoke low speeds of degradation. If it occurs in the ideal conditions of operation, the time needed to take to end the degradation of the phenol increases linearly with the concentration of phenol in the nourishment, whereas if in every cycle of operation a fixed volume of water is treated, the time needed increases much more rapidly with the concentration of phenol. (Author) 14 refs.

  11. Phenolic compounds in flaxseed

    OpenAIRE

    Johnsson, Pernilla

    2004-01-01

    The dietary lignan secoisolariciresinol diglucoside (SDG), present in high concentrations in flaxseed, and its metabolites enterolactone and enterodiol are thought to decrease the risk of hormone dependent cancers, cardiovascular disease and other “welfare” diseases. Flaxseed also contains other biologically active phenolic compounds, such as phenolic acids. The understanding of the nature of these compounds is crucial for their possible exploitation in drugs and functional foods. Until the m...

  12. Photodegradation of phenol on Y2O3 surface: synergism by semiconductors.

    Science.gov (United States)

    Karunakaran, C; Dhanalakshmi, R; Anilkumar, P

    2009-08-15

    Under UV light, phenol degrades on the surface of Y(2)O(3), an insulator, and the degradation follows first-order kinetics, depends linearly on the light intensity and slows down with pH. The efficiency of degradation is higher with UV-C light than with UV-A light. While particulate anatase TiO(2), ZnO, ZnS, Fe(2)O(3), CuO, CdO, and Nb(2)O(5) individually photodegrade phenol, each semiconductor shows synergism when present along with Y(2)O(3), indicating electron-transfer from phenol adsorbed on Y(2)O(3) to the illuminated semiconductors.

  13. Photodegradation and removal of phenol and phenolic derivatives from petroleum refinery wastewater using nanoparticles of TiO2

    Energy Technology Data Exchange (ETDEWEB)

    Shahrezaei, F. [Academic Center for Education, Culture & Research (ACECR), Kermanshah (Iran, Islamic Republic of); Akhbari, A. [Department of Analytical Chemistry, Faculty of Chemistry, Razi University, Kermanshah (Iran, Islamic Republic of); Water and Wastewater Research Center (WWRC), Razi University, Kermanshah (Iran, Islamic Republic of); Rostami, A. [Kermanshah Oil Refinery company, R& amp; D department (KORC), Kermanshah (Iran, Islamic Republic of)

    2012-07-01

    This study explores the potential application of TiO2 photocatalysis as primary degradation system of phenol and phenolic derivatives from refinery wastewater. The removal of phenol was investigated in terms of various parameters namely: pH, temperature and catalyst concentration. Determination of phenol and phenolic derivatives compounds is carried out by gas chromatography using a flame ionization detector. In order to analyze the process, chemical oxygen demand fraction (R) was studied. The region of the exploration for the process was taken as the area enclosed by pH (2-10), temperature (293-318 k) and catalyst concentration (10-200 mg/l) boundaries. The optimum conditions for phenol and phenolic derivatives removal were found to be 3, 318 k and 100 mg/l, respectively, for pH, temperature and catalyst concentration. The results showed that, at optimum conditions, remarkable removal of 90% of phenol after 2 h can be achieved. The main feature of this work is the use of inexpensive and recoverable catalyst and may be considered for preliminary application in the refinery wastewater treatments after physicochemical treatments to avoid solids and colloids.

  14. Electrochemical catalytic treatment of phenol wastewater

    International Nuclear Information System (INIS)

    Ma Hongzhu; Zhang Xinhai; Ma Qingliang; Wang Bo

    2009-01-01

    The slurry bed catalytic treatment of contaminated water appears to be a promising alternative for the oxidation of aqueous organic pollutants. In this paper, the electrochemical oxidation of phenol in synthetic wastewater catalyzed by ferric sulfate and potassium permanganate adsorbed onto active bentonite in slurry bed electrolytic reactor with graphite electrode has been investigated. In order to determine the optimum operating condition, the orthogonal experiments were devised and the results revealed that the system of ferric sulfate, potassium permanganate and active bentonite showed a high catalytic efficiency on the process of electrochemical oxidation phenol in initial pH 5. When the initial concentration of phenol was 0.52 g/L (the initial COD 1214 mg/L), up to 99% chemical oxygen demand (COD) removal was obtained in 40 min. According to the experimental results, a possible mechanism of catalytic degradation of phenol was proposed. Environmental estimation was also done and the results showed that the treated wastewater have little impact on plant growth and could totally be applied to irrigation.

  15. Phenolics and Plant Allelopathy

    Directory of Open Access Journals (Sweden)

    De-An Jiang

    2010-12-01

    Full Text Available Phenolic compounds arise from the shikimic and acetic acid (polyketide metabolic pathways in plants. They are but one category of the many secondary metabolites implicated in plant allelopathy. Phenolic allelochemicals have been observed in both natural and managed ecosystems, where they cause a number of ecological and economic problems, such as declines in crop yield due to soil sickness, regeneration failure of natural forests, and replanting problems in orchards. Phenolic allelochemical structures and modes of action are diverse and may offer potential lead compounds for the development of future herbicides or pesticides. This article reviews allelopathic effects, analysis methods, and allelopathic mechanisms underlying the activity of plant phenolic compounds. Additionally, the currently debated topic in plant allelopathy of whether catechin and 8-hydroxyquinoline play an important role in Centaurea maculata and Centaurea diffusa invasion success is discussed. Overall, the main purpose of this review is to highlight the allelopacthic potential of phenolic compounds to provide us with methods to solve various ecology problems, especially in regard to the sustainable development of agriculture, forestry, nature resources and environment conservation.

  16. Evaluation of the Antioxidant Properties of Litchi Fruit Phenolics in Relation to Pericarp Browning Prevention

    Directory of Open Access Journals (Sweden)

    Xuewu Duan

    2007-04-01

    Full Text Available Phenolics were extracted from litchi fruit pericarp (LFP tissues, purified and their antioxidant properties analyzed. LFP phenolics strongly inhibited linoleic acid oxidation and exhibited a dose-dependent free-radical scavenging activity against α,α-diphenyl-β-picrylhydrazyl (DPPH· and hydroxyl radicals and superoxide anions. The degradation of deoxyribose by hydroxyl radicals was inhibited by phenolics acting mainly as iron ion chelators, rather than by directly scavenging the radicals. Phenolics from litchi fruit pericarp were found to display similar reducing power activity as ascorbic acid. The effect of phenolic compound treatment on pericarp browning and electrolyte leakage of litchi fruit was also evaluated and it was observed that application of exogenous litchi phenolics to harvested litchi fruit significantly prevented pericarp browning and delayed increases in electrolyte leakage. These results suggest that litchi pericarp tissue phenolics could be beneficial in scavenging free radicals, maintaining membrane integrity and, thereby inhibiting pericarp browning of litchi fruit.

  17. Introduced Pine Sawfly

    Science.gov (United States)

    Louis F. Wilson

    1966-01-01

    The introduced pine, sawfly (Diprion similis (Hartig)) in North America was first discovered in 1914 in a nursery in New Haven, Conn. This insect might have been introduced in the cocoon stage on nursery stock or packing material from Holland. Since its arrival, it has advanced steadily westward, reaching Pennsylvania before 1920 and Ontario by 1931. The present range...

  18. Phenolic acid-based poly(anhydride-esters) as antioxidant biomaterialsa

    OpenAIRE

    Prudencio, Almudena; Faig, Jonathan J.; Song, MinJung; Uhrich, Kathryn E.

    2015-01-01

    Poly(anhydride-esters) comprised of naturally occurring, non-toxic phenolic acids, namely syringic and vanillic acid, with antioxidant properties were prepared via solution polymerization methods. Polymer and polymer precursor physiochemical properties were characterized, including polymer molecular weight and thermal properties. In vitro release studies illustrated that polymer hydrolytic degradation was influenced by relative hydrophobicity and degree of methoxy substitution of the phenolic...

  19. Effect of enzyme treatment during mechanical extraction of olive oil on phenolic compounds and polysaccharides

    NARCIS (Netherlands)

    Vierhuis, E.; Maurizio, S.; Baldioli, M.; Schols, H.A.; Voragen, A.G.J.; Montedoro, G.F.

    2001-01-01

    The effect of the use of cell-wall-degrading-enzyme preparations during the mechanical extraction process of virgin olive oil on the phenolic compounds and polysaccharides was investigated. The use of the enzyme preparations increased the concentration of phenolic compounds in the paste, oil, and

  20. Phenol recovery with liquid ammonia

    Energy Technology Data Exchange (ETDEWEB)

    Heilman

    1943-08-03

    This report covers the results of a phenol recovery plant at Ludwigshafen which had recently suffered a severe explosion. From a Gelsenberg hydrogenation middle oil with 18 percent phenol, an 86 to 96 percent phenol fraction was recovered. Because the occurring neutral oil was phenol-free and because with the process a phenol loss was impossible, it was assumed that the yield was quantitative. With regard to the working process, the middle oil was fed into the upper section of a column four feet high, in which liquid ammonia from below climbed upward. The ammonia thereby absorbed the phenol quantitatively, and the ammonium phenolate solution absorbed a certain amount of neutral oil. The loaded ammonia went over the top of the column while at the foot of the column the phenol-free neutral oil collected and was drawn off. The ammonium phenolate solution was then washed with light gasoline in a second column. For this, the ammonia was fed into the upper, the light gasoline into the lower part of the column. The light gasoline absorbed almost quantitatively the neutral oil which was molecularly or actually colloidally dissolved in the ammonium phenolate solution, and even a small amount of the phenol and ammonia. Thickening in concentration, the light gasoline was fed into a storage tank where it was freed of its dissolved components by atmospheric distillation and recycled into the process. The ammonium phenolate solution which before the gasoline wash left behind a vaporization residue with about 40 percent phenol afterwards produced a raw phenol of 86 to 96 percent pure phenol. Because of technical difficulties, the concentration of the washed ammonium phenolate solution could not be determined. It was gathered at the bottom of the second column and fed into a storage tank where the phenol was freed by pressure distillation. The ammonia was then recycled into the process.

  1. The regulation by phenolic compounds of soil organic matter dynamics under a changing environment.

    Science.gov (United States)

    Min, Kyungjin; Freeman, Chris; Kang, Hojeong; Choi, Sung-Uk

    2015-01-01

    Phenolics are the most abundant plant metabolites and are believed to decompose slowly in soils compared to other soil organic matter (SOM). Thus, they have often been considered as a slow carbon (C) pool in soil dynamics models. Here, however, we review changes in our concept about the turnover rate of phenolics and quantification of different types of phenolics in soils. Also, we synthesize current research on the degradation of phenolics and their regulatory effects on decomposition. Environmental changes, such as elevated CO2, warming, nitrogen (N) deposition, and drought, could influence the production and form of phenolics, leading to a change in SOM dynamics, and thus we also review the fate of phenolics under environmental disturbances. Finally, we propose the use of phenolics as a tool to control rates of SOM decomposition to stabilize organic carbon in ecosystems. Further studies to clarify the role of phenolics in SOM dynamics should include improving quantification methods, elucidating the relationship between phenolics and soil microorganisms, and determining the interactive effects of combinations of environmental changes on the phenolics production and degradation and subsequent impact on SOM processing.

  2. Response of low-strength phenol-acclimated activated sludge to ...

    African Journals Online (AJOL)

    2013-10-07

    -acclimated activated sludge,. (ii) investigate the degradation pathways and (iii) model the growth and biodegradation kinetics, all under the condition of increasingly higher phenol concentrations (step-up shock loading).

  3. Sorption of phenol and phenol derivatives in hydrotalcite; Sorcion de fenol y derivados de fenol en hidrotalcita

    Energy Technology Data Exchange (ETDEWEB)

    Avina G, E.I

    2002-07-01

    One of the main problems in Mexico and in the World is the waste water pollution of a great variety of industrial processes by organic compounds. Among those ones the phenol compounds which are highly toxic, refractories (to the chemical degradation) and poorly biodegradable. This is due in a large extent to the problem created by the accelerated increase in the environmental pollution in the cities and industrial centers. The phenol compounds are used in a great variety of industries such as the production of resins, plasticizers, antioxidants, pesticides, colourings, disinfectants, etc. These phenol compounds are specially harmful, since they have repercussions on the flora of plants of biological treatment of water affecting its operation. The main objective of this work is to evaluate the capacities of phenol detention and its derivatives in an hydrotalcite type compound and diminishing with it the presence in water, in this case, of solutions prepared in the laboratory. In order to analyse this elimination process was used a methodology based in the carrying out in batch experiments and in the elaboration of a sorption isotherm. It is worth pointing out that this work was realized at laboratory scale, at relatively high phenol concentration ratio. With the obtained results when the sorption properties are evaluated the calcined hydrotalcite (HTC) for detaining phenol and p-chloro phenol it was observed that it is detained greater quantity of p-chloro phenol than phenol in the HTC. The detention of these phenol compounds in the HTC is due to the memory effect by the hydrotalcite regeneration starting from the oxides which are formed by the burning material. (Author)

  4. Improving FTIR imaging speciation of organic compound residues or their degradation products in wall painting samples, by introducing a new thin section preparation strategy based on cyclododecane pre-treatment.

    Science.gov (United States)

    Papliaka, Zoi Eirini; Vaccari, Lisa; Zanini, Franco; Sotiropoulou, Sophia

    2015-07-01

    Fourier transform infrared (FTIR) imaging in transmission mode, employing a bidimensional focal plane array (FPA) detector, was applied for the detection and spatially resolved chemical characterisation of organic compounds or their degradation products within the stratigraphy of a critical group of fragments, originating from prehistoric and roman wall paintings, containing a very low concentration of subsisted organic matter or its alteration products. Past analyses using attenuated total reflection (ATR) or reflection FTIR on polished cross sections failed to provide any evidence of any organic material assignable as binding medium of the original painting. In order to improve the method's performance, in the present study, a new method of sample preparation in thin section was developed. The procedure is based on the use of cyclododecane C12H24 as embedding material and a subsequent double-side polishing of the specimen. Such procedure provides samples to be studied in FTIR transmission mode without losing the information on the spatial distribution of the detected materials in the paint stratigraphy. For comparison purposes, the same samples were also studied after opening their stratigraphy with a diamond anvil cell. Both preparation techniques offered high-quality chemical imaging of the decay products of an organic substance, giving clues to the painting technique. In addition, the thin sections resulting from the cyclododecane pre-treatment offered more layer-specific data, as the layer thickness and order remained unaffected, whereas the samples resulting from compression within the diamond cell were slightly deformed; however, since thinner and more homogenous, they provided higher spectral quality in terms of S/N ratio. In summary, the present study illustrates the appropriateness of FTIR imaging in transmission mode associated with a new thin section preparation strategy to detect and localise very low-concentrated organic matter subjected to

  5. Introduced Terrestrial Species Richness

    Data.gov (United States)

    U.S. Environmental Protection Agency — These data represent predicted current distributions of all introduced mammals, birds, reptiles, amphibians and butterflies in the Middle-Atlantic region. These data...

  6. Phenolic Compounds in Brassica Vegetables

    OpenAIRE

    Cartea González, María Elena; Francisco Candeira, Marta; Soengas Fernández, María del Pilar; Velasco Pazos, Pablo

    2011-01-01

    Phenolic compounds are a large group of phytochemicals widespread in the plant kingdom. Depending on their structure they can be classified into simple phenols, phenolic acids, hydroxycinnamic acid derivatives and flavonoids. Phenolic compounds have received considerable attention for being potentially protective factors against cancer and heart diseases, in part because of their potent antioxidative properties and their ubiquity in a wide range of commonly consumed foods of plant origin. The...

  7. Phenolic compounds in Ecuadorian fruits

    OpenAIRE

    Vasco, Catalina

    2009-01-01

    A group of eighteen fruits cultivated in Ecuador were evaluated for their total soluble phenolic compounds and antioxidant activity and attempts were made to identify the group and content of phenolic compounds responsible for the antioxidant activity. In terms of total phenolic content, three groups (with 1000 mg gallic acid equivalents/100 g FW) were clearly distinguishable. RP-HPLC-DAD and/or LC-MS/MS were used to study the phenolic compounds in four Rosaceae fruits (Andean blackberry, str...

  8. Effects of phenolic acid structures on meadow hay digestibility

    NARCIS (Netherlands)

    Rodrigues, M.A.M.; Guedes, C.M.; Cone, J.W.; Gelder, van A.H.; Ferreira, L.M.M.; Sequeira, C.A.

    2007-01-01

    The objectives were to evaluate effects of phenolic acid content and composition on the digestibility of six meadow hays from Northern Portugal. Digestibility was assessed by gas production, in vitro and in situ degradation methods. Four cows fed diets at energy maintenance were used for in situ

  9. Anaerobic treatment of phenolic coal conversion wastewater in semicontinuous cultures

    Energy Technology Data Exchange (ETDEWEB)

    Fedorak, P.M.; Hrudey, S.E.

    1986-01-01

    Effluent from the H-coal process was treated with methanogenic cultures. During a stable period, virtually all the phenol and p- and m-cresol was removed; thereafter, the three compounds began to appear in the outflow, o-Cresol was not degraded under these conditions. Methane production was monitored.

  10. Degradation of Chlorinated Aromatic Compounds in UASB Reactors

    DEFF Research Database (Denmark)

    Christiansen, Nina; Hendriksen, Hanne Vang; Järvinen, Kimmo T.

    1995-01-01

    Data on anaerobic degradation of chloroaromatic compounds in Upflow Anaerobic Sludge Blanket Reactors (UASB-reactor) are presented and compared. Special attention is given to the metabolic pathways for degradation of chlorinated phenols by granular sludge. Results indicate that PCP can be degraded...... in UASB-reactors via stepwise dechlorination to phenol. Phenol will subsequently be converted to benzoate before ring cleavage. Dechlorination proceeds via different pathways dependent upon the inocula used. Results are further presented on the design of special metabolic pathways in granules which do...

  11. METHODS OF REDUCTION OF FREE PHENOL CONTENT IN PHENOLIC FOAM

    Directory of Open Access Journals (Sweden)

    Bruyako Mikhail Gerasimovich

    2012-12-01

    method aimed at reduction of toxicity of phenolic foams consists in the introduction of a composite mixture of chelate compounds. Raw materials applied in the production of phenolic foams include polymers FRB-1A and VAG-3. The aforementioned materials are used to produce foams FRP-1. Introduction of 1% aluminum fluoride leads to the 40% reduction of the free phenol content in the foam. Introduction of crystalline zinc chloride accelerates the foaming and curing of phenolic foams. The technology that contemplates the introduction of zeolites into the mixture includes pre-mixing with FRB -1A and subsequent mixing with VAG-3; thereafter, the composition is poured into the form, in which the process of foaming is initiated. The content of free phenol was identified using the method of UV spectroscopy. The objective of the research was to develop methods of reduction of the free phenol content in the phenolic foam.

  12. Fabrication of the novel core-shell MCM-41@mTiO{sub 2} composite microspheres with large specific surface area for enhanced photocatalytic degradation of dinitro butyl phenol (DNBP)

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Xiao-Na; Wang, Hui-Long, E-mail: hlwang@dlut.edu.cn; Li, Zhen-Duo; Huang, Zhi-Qiang; Qi, Hui-Ping; Jiang, Wen-Feng

    2016-05-30

    Graphical abstract: The mesoporous MCM-41@mTiO{sub 2} composite microspheres with core/shell structure, well-crystallized mesoporous TiO{sub 2} layer, high specific surface, large pore volume and excellent photocatalytic activity were synthesized by combining sol-gel and simple hydrothermal treatment. - Highlights: • The mesoporous MCM-41@mTiO{sub 2} composite was synthesized successfully. • The composite was facilely prepared by combining sol-gel and hydrothermal method. • The composite exhibited high photocatalytic degradation activity for DNBP. • The composite photocatalyst has excellent reproducibility. - Abstract: The mesoporous MCM-41@mTiO{sub 2} core-shell composite microspheres were synthesized successfully by combining sol-gel and simple hydrothermal treatment. The morphology and microstructure characteristics of the synthesized materials were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), N{sub 2} adsorption-desorption measurements, X-ray powder diffraction (XRD), UV–vis diffuse reflectance spectra (UV–vis/DRS) and Fourier transform infrared spectroscopy (FT-IR). The results indicate that the composite material possesses obvious core/shell structure, a pure mesoporous and well-crystallized TiO{sub 2} layer (mTiO{sub 2}), high specific surface area (316.8 m{sup 2}/g), large pore volume (0.42 cm{sup 3}/g) and two different pore sizes (2.6 nm and 11.0 nm). The photocatalytic activity of the novel MCM-41@mTiO{sub 2} composite was evaluated by degrading 2-sec-butyl-4,6-dinitrophenol (DNBP) in aqueous suspension under UV and visible light irradiation. The results were compared with commercial anatase TiO{sub 2} and Degussa P25 and the enhanced degradation were obtained with the synthesized MCM-41@mTiO{sub 2} composite under the same conditions, which meant that this material can serve as an efficient photocatalyst for the degradation of hazardous organic pollutants in wastewaters.

  13. Introducing ZBrush 4

    CERN Document Server

    Keller, Eric

    2011-01-01

    Introducing ZBrush 4 launches readers head-on into fulfilling their artistic potential for sculpting realistic creature, cartoon, and hard surface models in ZBrush. ZBrush's innovative technology and interface can be intimidating to both digital-art beginners as well as veterans who are used to a more conventional modeling environment. This book dispels myths about the difficulty of ZBrush with a thorough tour and exploration of the program's interface. Engaging projects also allow the reader to become comfortable with digital sculpting in with a relaxed and fun book atmosphere. Introducing ZB

  14. Phenolic Compounds in Brassica Vegetables

    Directory of Open Access Journals (Sweden)

    Pablo Velasco

    2010-12-01

    Full Text Available Phenolic compounds are a large group of phytochemicals widespread in the plant kingdom. Depending on their structure they can be classified into simple phenols, phenolic acids, hydroxycinnamic acid derivatives and flavonoids. Phenolic compounds have received considerable attention for being potentially protective factors against cancer and heart diseases, in part because of their potent antioxidative properties and their ubiquity in a wide range of commonly consumed foods of plant origin. The Brassicaceae family includes a wide range of horticultural crops, some of them with economic significance and extensively used in the diet throughout the world. The phenolic composition of Brassica vegetables has been recently investigated and, nowadays, the profile of different Brassica species is well established. Here, we review the significance of phenolic compounds as a source of beneficial compounds for human health and the influence of environmental conditions and processing mechanisms on the phenolic composition of Brassica vegetables.

  15. Characterization of phenols biodegradation by compound specific stable isotope analysis

    Science.gov (United States)

    Wei, Xi; Gilevska, Tetyana; Wenzig, Felix; Hans, Richnow; Vogt, Carsten

    2015-04-01

    Biodegradation of phenol and alkylphenols has been described under both oxic and anoxic conditions. In the absence of molecular oxygen, the degradation of phenolic compounds is initiated by microorganisms through carboxylation, fumarate addition to the methyl moiety or anoxic hydroxylation of the methyl moiety. Comparatively, under aerobic condition, the initiation mechanisms are revealed to be monoxygenation or dihydroxylation for phenol and ring hydroxylation or methyl group oxidation for cresols. While several studies biochemically characterized the enzymes and reaction mechanisms in the relevant degradation pathways, isotope fractionation patterns were rarely reported possibly due to constraints in current analytical methods. In this study, the carbon isotope fractionation patterns upon the degradation of phenol and cresols by several strains were analyzed by using isotope ratio mass spectrometry connected with liquid chromatography (LC-IRMS). The corresponding enrichment factors for carbon (ƐC) have been obtained. Cresols degradation by various strains showed generally moderate carbon isotope fractionation patterns with notable differences. For p-cresol degradation, five strains were examined. The aerobic strain Acinetobacter calcoaceticus NCIMB8250 exploits ring hydroxylation by molecular oxygen as initial reaction, and a ƐC value of -1.4±0.2‰ was obtained. Pseudomonas pseudoalcaligenes NCIMB 9867, an aerobic strain initiating cresols degradation via oxygen-dependent side chain hydroxylation, yielded a ƐC value of -2.3±0.2‰. Under nitrate-reducing conditions, Geobacter metallireducens DSM 7210 and Azoarcus buckelii DSM 14744 attacks p-cresol at the side chain by monohydroxylation using water as oxygen source; the two strains produced ƐC values of -3.6±0.4‰ and -2±0.1‰, accordingly. The sulfate-reducing Desulfosarcina cetonica DSM 7267 activating cresols by fumarate addition to the methyl moiety yielded ƐC values of -1.9±0.2‰ for p

  16. In situ and laboratory determined first-order degradation rate constants of specific organic compounds in an aerobic aquifer

    DEFF Research Database (Denmark)

    Nielsen, P.H.; Bjerg, P.L.; Nielsen, P.

    1996-01-01

    , tetrachloroethene, phenol, o-cresol, 2,4- and 2,6-dichlorophenol, 4,6-o-dichlorocresol, and o- and p-nitrophenol in an aerobic aquifer, All aromatic hydrocarbons were degraded in ISM and LBM experiments. The phenolic hydrocarbons were ail degraded in ISM experiments, but some failed to degrade in LBM experiments...

  17. Introducing Electromagnetic Field Momentum

    Science.gov (United States)

    Hu, Ben Yu-Kuang

    2012-01-01

    I describe an elementary way of introducing electromagnetic field momentum. By considering a system of a long solenoid and line charge, the dependence of the field momentum on the electric and magnetic fields can be deduced. I obtain the electromagnetic angular momentum for a point charge and magnetic monopole pair partially through dimensional…

  18. Introducing Business English

    NARCIS (Netherlands)

    Nickerson, C.; Planken, B.C.

    2015-01-01

    Introducing Business English provides a comprehensive overview of this topic, situating the concepts of Business English and English for Specific Business Purposes within the wider field of English for Special Purposes. This book draws on contemporary teaching and research contexts to demonstrate

  19. Aggregation of immobilized activated sludge cells into aerobically grown microbial granules for the aerobic biodegradation of phenol.

    Science.gov (United States)

    Jiang, H-L; Tay, J-H; Tay, S T-L

    2002-01-01

    The aim of this study is to evaluate the utility of aerobically grown microbial granules for the biological treatment of phenol-containing wastewater. A column-type sequential aerobic sludge blanket reactor was inoculated with activated sludge and fed with phenol as the sole carbon source, at a rate of 1.5 g phenol l-1 d-1. Aerobically grown microbial granules first appeared on day 9 of reactor operation and quickly grew to displace the seed flocs as the dominant form of biomass in the reactor. These granules were compact and regular in appearance, and consisted of bacterial rods and cocci and fungi embedded in an extracellular polymeric matrix. The granules had a mean size of 0.52 mm, a sludge volume index of 40 ml g-1 and a specific oxygen utilization rate of 110 mg oxygen g VSS-1 h-1 (VSS stands for volatile suspended solids). Specific phenol degradation rates increased with phenol concentration from 0 to 500 mg phenol l-1, peaked at 1.4 g phenol g VSS-1 d-1, and declined with further increases in phenol concentration as substrate inhibition effects became important. Aerobically grown microbial granules were successfully cultivated in a reactor maintained at a loading rate of 1.5 g phenol l-1 d-1. The granules exhibited a high tolerance towards phenol. Significant rates of phenol degradation were attained at phenol concentrations as high as 2 g l-1. This is the first study to demonstrate the ability of aerobically grown microbial granules to degrade phenol. These granules appear to represent an excellent immobilization strategy for microorganisms to biologically remove phenol and other toxic chemicals in high-strength industrial wastewaters.

  20. Enzyme release of phenolics from muscadine grape (Vitis rotundifolia Michx.) skins and seeds.

    Science.gov (United States)

    Xu, Changmou; Yagiz, Yavuz; Borejsza-Wysocki, Wlodzimierz; Lu, Jiang; Gu, Liwei; Ramírez-Rodrigues, Milena M; Marshall, Maurice R

    2014-08-15

    Enzyme degradation of plant cell wall polysaccharides can potentially enhance the release of bioactive phenolics. The aim of this study was to evaluate various combinations of solvent and enzyme, enzyme type (cellulase, pectinase, ß-glucosidase), and hydrolysis time (1, 4, 8, 24 h) on the release of muscadine grape skin and seed phenolics, and their antioxidant activities. Results showed that pre-treated muscadine skins and seeds with enzymes decreased total phenolic yield compared with solvent (50% ethanol) alone. Enzyme release of phenolics from skins of different muscadine varieties was significantly different while release from seeds was similar. Enzyme hydrolysis was found to shorten extraction time. Most importantly, enzyme hydrolysis modified the galloylated form of polyphenols to low molecular weight phenolics, releasing phenolic acids (especially gallic acid), and enhancing antioxidant activity. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Bioremediation of phenols and polycyclic aromatic hydrocarbons in creosote contaminated soil using ex-situ landtreatment.

    Science.gov (United States)

    Guerin, T F

    1999-03-19

    Soil from a former creosoting plant containing phenols and polycyclic aromatic hydrocarbons, was remediated using an ex-situ landtreatment process. Total 16 USEPA priority PAH and total phenol were reduced from 290 mg/kg and 40 mg/kg to bioremediation process involved soil mixing, aeration, and slow release fertilizer addition. The indigenous populations of PAH and phenol utilizing populations of microorganisms were shown to increase during the treatment process, indicating that biostimulation was effective. The most extensive degradation was apparent with the 2- and 3-ring PAH, with decreases of 97% and 82%, respectively. The higher molecular weight 3- and 4-ring PAH were degraded at slower rates, with reductions of 45% and 51%, respectively. Six-ring PAH were degraded the least with average reductions of < 35%. The residual concentrations of PAH and total phenol obtained in the study allowed the treated soil to be disposed of as low level contaminated landfill.

  2. [Effects of aniline and phenol on freshwater algae growth].

    Science.gov (United States)

    Chen, Chuan-ping; Zhang, Ting-ting; He, Mei; Wu, An-ping; Nie, Liu-wang

    2007-01-01

    By the methods of bioassay, this paper studied the effects of aniline or phenol on the growth of Chlorella pyrenoidosa and Scenedesmus obiquus. The results showed that these two compounds had evident effects on the growth of test algae species. For the same species, aniline was more toxic. Under the same concentration of the compounds, S. obiquus was more sensitive than C. pyrenoidosa. These two algae species could degrade or absorb parts of the compounds, and phenol in particular, when their concentrations were lower.

  3. Biodegradation of phenols in a sandstone aquifer under aerobic conditions and mixed nitrate and iron reducing conditions

    DEFF Research Database (Denmark)

    Broholm, Mette; Arvin, Erik

    2000-01-01

    Ammonia liquor with very high concentrations of phenol and alkylated phenols is known to have leaked into the subsurface at a former coal carbonization plant in the UK, giving high concentrations of ammonium in the groundwater. In spite of this, no significant concentrations of phenols were found...... to 5 mg 1(-1): high: similar to 60 mg 1(-1), and very high: similar to 600 mg 1(-1)) and in the presence of other organic coal-tar compounds (mono- and polyaromatic hydrocarbons (BTEXs and PAHs) and heterocyclic compounds (NSOs)) and ammonia liquor. Sandstone cores and groundwater for the microcosms...... degradation of phenols in unamended microcosms. The effect of other organic coal-tar compounds (BTEXs, PAWs, NSOs) on the degradation of the phenols under unamended conditions was limited to slightly longer lag-phases fur some of the phenols. Other constituents of the ammonia liquor did not appear...

  4. Introducing Program Evaluation Models

    Directory of Open Access Journals (Sweden)

    Raluca GÂRBOAN

    2008-02-01

    Full Text Available Programs and project evaluation models can be extremely useful in project planning and management. The aim is to set the right questions as soon as possible in order to see in time and deal with the unwanted program effects, as well as to encourage the positive elements of the project impact. In short, different evaluation models are used in order to minimize losses and maximize the benefits of the interventions upon small or large social groups. This article introduces some of the most recently used evaluation models.

  5. Introducing the CTA concept

    Science.gov (United States)

    Acharya, B. S.; Actis, M.; Aghajani, T.; Agnetta, G.; Aguilar, J.; Aharonian, F.; Ajello, M.; Akhperjanian, A.; Alcubierre, M.; Aleksić, J.; Alfaro, R.; Aliu, E.; Allafort, A. J.; Allan, D.; Allekotte, I.; Amato, E.; Anderson, J.; Angüner, E. O.; Antonelli, L. A.; Antoranz, P.; Aravantinos, A.; Arlen, T.; Armstrong, T.; Arnaldi, H.; Arrabito, L.; Asano, K.; Ashton, T.; Asorey, H. G.; Awane, Y.; Baba, H.; Babic, A.; Baby, N.; Bähr, J.; Bais, A.; Baixeras, C.; Bajtlik, S.; Balbo, M.; Balis, D.; Balkowski, C.; Bamba, A.; Bandiera, R.; Barber, A.; Barbier, C.; Barceló, M.; Barnacka, A.; Barnstedt, J.; Barres de Almeida, U.; Barrio, J. A.; Basili, A.; Basso, S.; Bastieri, D.; Bauer, C.; Baushev, A.; Becerra, J.; Becherini, Y.; Bechtol, K. C.; Becker Tjus, J.; Beckmann, V.; Bednarek, W.; Behera, B.; Belluso, M.; Benbow, W.; Berdugo, J.; Berger, K.; Bernard, F.; Bernardino, T.; Bernlöhr, K.; Bhat, N.; Bhattacharyya, S.; Bigongiari, C.; Biland, A.; Billotta, S.; Bird, T.; Birsin, E.; Bissaldi, E.; Biteau, J.; Bitossi, M.; Blake, S.; Blanch Bigas, O.; Blasi, P.; Bobkov, A.; Boccone, V.; Boettcher, M.; Bogacz, L.; Bogart, J.; Bogdan, M.; Boisson, C.; Boix Gargallo, J.; Bolmont, J.; Bonanno, G.; Bonardi, A.; Bonev, T.; Bonifacio, P.; Bonnoli, G.; Bordas, P.; Borgland, A.; Borkowski, J.; Bose, R.; Botner, O.; Bottani, A.; Bouchet, L.; Bourgeat, M.; Boutonnet, C.; Bouvier, A.; Brau-Nogué, S.; Braun, I.; Bretz, T.; Briggs, M.; Bringmann, T.; Brook, P.; Brun, P.; Brunetti, L.; Buanes, T.; Buckley, J.; Buehler, R.; Bugaev, V.; Bulgarelli, A.; Bulik, T.; Busetto, G.; Buson, S.; Byrum, K.; Cailles, M.; Cameron, R.; Camprecios, J.; Canestrari, R.; Cantu, S.; Capalbi, M.; Caraveo, P.; Carmona, E.; Carosi, A.; Carr, J.; Carton, P.-H.; Casanova, S.; Casiraghi, M.; Catalano, O.; Cavazzani, S.; Cazaux, S.; Cerruti, M.; Chabanne, E.; Chadwick, P.; Champion, C.; Chen, A.; Chiang, J.; Chiappetti, L.; Chikawa, M.; Chitnis, V. R.; Chollet, F.; Chudoba, J.; Cieślar, M.; Cillis, A.; Cohen-Tanugi, J.; Colafrancesco, S.; Colin, P.; Colome, J.; Colonges, S.; Compin, M.; Conconi, P.; Conforti, V.; Connaughton, V.; Conrad, J.; Contreras, J. L.; Coppi, P.; Corona, P.; Corti, D.; Cortina, J.; Cossio, L.; Costantini, H.; Cotter, G.; Courty, B.; Couturier, S.; Covino, S.; Crimi, G.; Criswell, S. J.; Croston, J.; Cusumano, G.; Dafonseca, M.; Dale, O.; Daniel, M.; Darling, J.; Davids, I.; Dazzi, F.; De Angelis, A.; De Caprio, V.; De Frondat, F.; de Gouveia Dal Pino, E. M.; de la Calle, I.; De La Vega, G. A.; de los Reyes Lopez, R.; De Lotto, B.; De Luca, A.; de Mello Neto, J. R. T.; de Naurois, M.; de Oliveira, Y.; de Oña Wilhelmi, E.; de Souza, V.; Decerprit, G.; Decock, G.; Deil, C.; Delagnes, E.; Deleglise, G.; Delgado, C.; Della Volpe, D.; Demange, P.; Depaola, G.; Dettlaff, A.; Di Paola, A.; Di Pierro, F.; Díaz, C.; Dick, J.; Dickherber, R.; Dickinson, H.; Diez-Blanco, V.; Digel, S.; Dimitrov, D.; Disset, G.; Djannati-Ataï, A.; Doert, M.; Dohmke, M.; Domainko, W.; Dominis Prester, D.; Donat, A.; Dorner, D.; Doro, M.; Dournaux, J.-L.; Drake, G.; Dravins, D.; Drury, L.; Dubois, F.; Dubois, R.; Dubus, G.; Dufour, C.; Dumas, D.; Dumm, J.; Durand, D.; Dyks, J.; Dyrda, M.; Ebr, J.; Edy, E.; Egberts, K.; Eger, P.; Einecke, S.; Eleftheriadis, C.; Elles, S.; Emmanoulopoulos, D.; Engelhaupt, D.; Enomoto, R.; Ernenwein, J.-P.; Errando, M.; Etchegoyen, A.; Evans, P.; Falcone, A.; Fantinel, D.; Farakos, K.; Farnier, C.; Fasola, G.; Favill, B.; Fede, E.; Federici, S.; Fegan, S.; Feinstein, F.; Ferenc, D.; Ferrando, P.; Fesquet, M.; Fiasson, A.; Fillin-Martino, E.; Fink, D.; Finley, C.; Finley, J. P.; Fiorini, M.; Firpo Curcoll, R.; Flores, H.; Florin, D.; Focke, W.; Föhr, C.; Fokitis, E.; Font, L.; Fontaine, G.; Fornasa, M.; Förster, A.; Fortson, L.; Fouque, N.; Franckowiak, A.; Fransson, C.; Fraser, G.; Frei, R.; Albuquerque, I. F. M.; Fresnillo, L.; Fruck, C.; Fujita, Y.; Fukazawa, Y.; Fukui, Y.; Funk, S.; Gäbele, W.; Gabici, S.; Gabriele, R.; Gadola, A.; Galante, N.; Gall, D.; Gallant, Y.; Gámez-García, J.; García, B.; Garcia López, R.; Gardiol, D.; Garrido, D.; Garrido, L.; Gascon, D.; Gaug, M.; Gaweda, J.; Gebremedhin, L.; Geffroy, N.; Gerard, L.; Ghedina, A.; Ghigo, M.; Giannakaki, E.; Gianotti, F.; Giarrusso, S.; Giavitto, G.; Giebels, B.; Gika, V.; Giommi, P.; Girard, N.; Giro, E.; Giuliani, A.; Glanzman, T.; Glicenstein, J.-F.; Godinovic, N.; Golev, V.; Gomez Berisso, M.; Gómez-Ortega, J.; Gonzalez, M. M.; González, A.; González, F.; González Muñoz, A.; Gothe, K. S.; Gougerot, M.; Graciani, R.; Grandi, P.; Grañena, F.; Granot, J.; Grasseau, G.; Gredig, R.; Green, A.; Greenshaw, T.; Grégoire, T.; Grimm, O.; Grube, J.; Grudzinska, M.; Gruev, V.; Grünewald, S.; Grygorczuk, J.; Guarino, V.; Gunji, S.; Gyuk, G.; Hadasch, D.; Hagiwara, R.; Hahn, J.; Hakansson, N.; Hallgren, A.; Hamer Heras, N.; Hara, S.; Hardcastle, M. J.; Harris, J.; Hassan, T.; Hatanaka, K.; Haubold, T.; Haupt, A.; Hayakawa, T.; Hayashida, M.; Heller, R.; Henault, F.; Henri, G.; Hermann, G.; Hermel, R.; Herrero, A.; Hidaka, N.; Hinton, J.; Hoffmann, D.; Hofmann, W.; Hofverberg, P.; Holder, J.; Horns, D.; Horville, D.; Houles, J.; Hrabovsky, M.; Hrupec, D.; Huan, H.; Huber, B.; Huet, J.-M.; Hughes, G.; Humensky, T. B.; Huovelin, J.; Ibarra, A.; Illa, J. M.; Impiombato, D.; Incorvaia, S.; Inoue, S.; Inoue, Y.; Ioka, K.; Ismailova, E.; Jablonski, C.; Jacholkowska, A.; Jamrozy, M.; Janiak, M.; Jean, P.; Jeanney, C.; Jimenez, J. J.; Jogler, T.; Johnson, T.; Journet, L.; Juffroy, C.; Jung, I.; Kaaret, P.; Kabuki, S.; Kagaya, M.; Kakuwa, J.; Kalkuhl, C.; Kankanyan, R.; Karastergiou, A.; Kärcher, K.; Karczewski, M.; Karkar, S.; Kasperek, J.; Kastana, D.; Katagiri, H.; Kataoka, J.; Katarzyński, K.; Katz, U.; Kawanaka, N.; Kellner-Leidel, B.; Kelly, H.; Kendziorra, E.; Khélifi, B.; Kieda, D. B.; Kifune, T.; Kihm, T.; Kishimoto, T.; Kitamoto, K.; Kluźniak, W.; Knapic, C.; Knapp, J.; Knödlseder, J.; Köck, F.; Kocot, J.; Kodani, K.; Köhne, J.-H.; Kohri, K.; Kokkotas, K.; Kolitzus, D.; Komin, N.; Kominis, I.; Konno, Y.; Köppel, H.; Korohoda, P.; Kosack, K.; Koss, G.; Kossakowski, R.; Kostka, P.; Koul, R.; Kowal, G.; Koyama, S.; Kozioł, J.; Krähenbühl, T.; Krause, J.; Krawzcynski, H.; Krennrich, F.; Krepps, A.; Kretzschmann, A.; Krobot, R.; Krueger, P.; Kubo, H.; Kudryavtsev, V. A.; Kushida, J.; Kuznetsov, A.; La Barbera, A.; La Palombara, N.; La Parola, V.; La Rosa, G.; Lacombe, K.; Lamanna, G.; Lande, J.; Languignon, D.; Lapington, J.; Laporte, P.; Lavalley, C.; Le Flour, T.; Le Padellec, A.; Lee, S.-H.; Lee, W. H.; Leigui de Oliveira, M. A.; Lelas, D.; Lenain, J.-P.; Leopold, D. J.; Lerch, T.; Lessio, L.; Lieunard, B.; Lindfors, E.; Liolios, A.; Lipniacka, A.; Lockart, H.; Lohse, T.; Lombardi, S.; Lopatin, A.; Lopez, M.; López-Coto, R.; López-Oramas, A.; Lorca, A.; Lorenz, E.; Lubinski, P.; Lucarelli, F.; Lüdecke, H.; Ludwin, J.; Luque-Escamilla, P. L.; Lustermann, W.; Luz, O.; Lyard, E.; Maccarone, M. C.; Maccarone, T. J.; Madejski, G. M.; Madhavan, A.; Mahabir, M.; Maier, G.; Majumdar, P.; Malaguti, G.; Maltezos, S.; Manalaysay, A.; Mancilla, A.; Mandat, D.; Maneva, G.; Mangano, A.; Manigot, P.; Mannheim, K.; Manthos, I.; Maragos, N.; Marcowith, A.; Mariotti, M.; Marisaldi, M.; Markoff, S.; Marszałek, A.; Martens, C.; Martí, J.; Martin, J.-M.; Martin, P.; Martínez, G.; Martínez, F.; Martínez, M.; Masserot, A.; Mastichiadis, A.; Mathieu, A.; Matsumoto, H.; Mattana, F.; Mattiazzo, S.; Maurin, G.; Maxfield, S.; Maya, J.; Mazin, D.; Mc Comb, L.; McCubbin, N.; McHardy, I.; McKay, R.; Medina, C.; Melioli, C.; Melkumyan, D.; Mereghetti, S.; Mertsch, P.; Meucci, M.; Michałowski, J.; Micolon, P.; Mihailidis, A.; Mineo, T.; Minuti, M.; Mirabal, N.; Mirabel, F.; Miranda, J. M.; Mirzoyan, R.; Mizuno, T.; Moal, B.; Moderski, R.; Mognet, I.; Molinari, E.; Molinaro, M.; Montaruli, T.; Monteiro, I.; Moore, P.; Moralejo Olaizola, A.; Mordalska, M.; Morello, C.; Mori, K.; Mottez, F.; Moudden, Y.; Moulin, E.; Mrusek, I.; Mukherjee, R.; Munar-Adrover, P.; Muraishi, H.; Murase, K.; Murphy, A.; Nagataki, S.; Naito, T.; Nakajima, D.; Nakamori, T.; Nakayama, K.; Naumann, C.; Naumann, D.; Naumann-Godo, M.; Nayman, P.; Nedbal, D.; Neise, D.; Nellen, L.; Neustroev, V.; Neyroud, N.; Nicastro, L.; Nicolau-Kukliński, J.; Niedźwiecki, A.; Niemiec, J.; Nieto, D.; Nikolaidis, A.; Nishijima, K.; Nolan, S.; Northrop, R.; Nosek, D.; Nowak, N.; Nozato, A.; O'Brien, P.; Ohira, Y.; Ohishi, M.; Ohm, S.; Ohoka, H.; Okuda, T.; Okumura, A.; Olive, J.-F.; Ong, R. A.; Orito, R.; Orr, M.; Osborne, J.; Ostrowski, M.; Otero, L. A.; Otte, N.; Ovcharov, E.; Oya, I.; Ozieblo, A.; Padilla, L.; Paiano, S.; Paillot, D.; Paizis, A.; Palanque, S.; Palatka, M.; Pallota, J.; Panagiotidis, K.; Panazol, J.-L.; Paneque, D.; Panter, M.; Paoletti, R.; Papayannis, A.; Papyan, G.; Paredes, J. M.; Pareschi, G.; Parks, G.; Parraud, J.-M.; Parsons, D.; Paz Arribas, M.; Pech, M.; Pedaletti, G.; Pelassa, V.; Pelat, D.; Perez, M. d. C.; Persic, M.; Petrucci, P.-O.; Peyaud, B.; Pichel, A.; Pita, S.; Pizzolato, F.; Platos, Ł.; Platzer, R.; Pogosyan, L.; Pohl, M.; Pojmanski, G.; Ponz, J. D.; Potter, W.; Poutanen, J.; Prandini, E.; Prast, J.; Preece, R.; Profeti, F.; Prokoph, H.; Prouza, M.; Proyetti, M.; Puerto-Gimenez, I.; Pühlhofer, G.; Puljak, I.; Punch, M.; Pyzioł, R.; Quel, E. J.; Quinn, J.; Quirrenbach, A.; Racero, E.; Rajda, P. J.; Ramon, P.; Rando, R.; Rannot, R. C.; Rataj, M.; Raue, M.; Reardon, P.; Reimann, O.; Reimer, A.; Reimer, O.; Reitberger, K.; Renaud, M.; Renner, S.; Reville, B.; Rhode, W.; Ribó, M.; Ribordy, M.; Richer, M. G.; Rico, J.; Ridky, J.; Rieger, F.; Ringegni, P.; Ripken, J.; Ristori, P. R.; Riviére, A.; Rivoire, S.; Rob, L.; Roeser, U.; Rohlfs, R.; Rojas, G.; Romano, P.; Romaszkan, W.; Romero, G. E.; Rosen, S.; Rosier Lees, S.; Ross, D.; Rouaix, G.; Rousselle, J.; Rousselle, S.; Rovero, A. C.; Roy, F.; Royer, S.; Rudak, B.; Rulten, C.; Rupiński, M.; Russo, F.; Ryde, F.; Sacco, B.; Saemann, E. O.; Saggion, A.; Sahakian, V.; Saito, K.; Saito, T.; Saito, Y.; Sakaki, N.; Sakonaka, R.; Salini, A.; Sanchez, F.; Sanchez-Conde, M.; Sandoval, A.; Sandaker, H.; Sant'Ambrogio, E.; Santangelo, A.; Santos, E. M.; Sanuy, A.; Sapozhnikov, L.; Sarkar, S.; Sartore, N.; Sasaki, H.; Satalecka, K.; Sawada, M.; Scalzotto, V.; Scapin, V.; Scarcioffolo, M.; Schafer, J.; Schanz, T.; Schlenstedt, S.; Schlickeiser, R.; Schmidt, T.; Schmoll, J.; Schovanek, P.; Schroedter, M.; Schultz, C.; Schultze, J.; Schulz, A.; Schure, K.; Schwab, T.; Schwanke, U.; Schwarz, J.; Schwarzburg, S.; Schweizer, T.; Schwemmer, S.; Segreto, A.; Seiradakis, J.-H.; Sembroski, G. H.; Seweryn, K.; Sharma, M.; Shayduk, M.; Shellard, R. C.; Shi, J.; Shibata, T.; Shibuya, A.; Shum, E.; Sidoli, L.; Sidz, M.; Sieiro, J.; Sikora, M.; Silk, J.; Sillanpää, A.; Singh, B. B.; Sitarek, J.; Skole, C.; Smareglia, R.; Smith, A.; Smith, D.; Smith, J.; Smith, N.; Sobczyńska, D.; Sol, H.; Sottile, G.; Sowiński, M.; Spanier, F.; Spiga, D.; Spyrou, S.; Stamatescu, V.; Stamerra, A.; Starling, R.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Steiner, S.; Stergioulas, N.; Sternberger, R.; Sterzel, M.; Stinzing, F.; Stodulski, M.; Straumann, U.; Strazzeri, E.; Stringhetti, L.; Suarez, A.; Suchenek, M.; Sugawara, R.; Sulanke, K.-H.; Sun, S.; Supanitsky, A. D.; Suric, T.; Sutcliffe, P.; Sykes, J.; Szanecki, M.; Szepieniec, T.; Szostek, A.; Tagliaferri, G.; Tajima, H.; Takahashi, H.; Takahashi, K.; Takalo, L.; Takami, H.; Talbot, G.; Tammi, J.; Tanaka, M.; Tanaka, S.; Tasan, J.; Tavani, M.; Tavernet, J.-P.; Tejedor, L. A.; Telezhinsky, I.; Temnikov, P.; Tenzer, C.; Terada, Y.; Terrier, R.; Teshima, M.; Testa, V.; Tezier, D.; Thuermann, D.; Tibaldo, L.; Tibolla, O.; Tiengo, A.; Tluczykont, M.; Todero Peixoto, C. J.; Tokanai, F.; Tokarz, M.; Toma, K.; Torii, K.; Tornikoski, M.; Torres, D. F.; Torres, M.; Tosti, G.; Totani, T.; Toussenel, F.; Tovmassian, G.; Travnicek, P.; Trifoglio, M.; Troyano, I.; Tsinganos, K.; Ueno, H.; Umehara, K.; Upadhya, S. S.; Usher, T.; Uslenghi, M.; Valdes-Galicia, J. F.; Vallania, P.; Vallejo, G.; van Driel, W.; van Eldik, C.; Vandenbrouke, J.; Vanderwalt, J.; Vankov, H.; Vasileiadis, G.; Vassiliev, V.; Veberic, D.; Vegas, I.; Vercellone, S.; Vergani, S.; Veyssiére, C.; Vialle, J. P.; Viana, A.; Videla, M.; Vincent, P.; Vincent, S.; Vink, J.; Vlahakis, N.; Vlahos, L.; Vogler, P.; Vollhardt, A.; von Gunten, H.-P.; Vorobiov, S.; Vuerli, C.; Waegebaert, V.; Wagner, R.; Wagner, R. G.; Wagner, S.; Wakely, S. P.; Walter, R.; Walther, T.; Warda, K.; Warwick, R.; Wawer, P.; Wawrzaszek, R.; Webb, N.; Wegner, P.; Weinstein, A.; Weitzel, Q.; Welsing, R.; Werner, M.; Wetteskind, H.; White, R.; Wierzcholska, A.; Wiesand, S.; Wilkinson, M.; Williams, D. A.; Willingale, R.; Winiarski, K.; Wischnewski, R.; Wiśniewski, Ł.; Wood, M.; Wörnlein, A.; Xiong, Q.; Yadav, K. K.; Yamamoto, H.; Yamamoto, T.; Yamazaki, R.; Yanagita, S.; Yebras, J. M.; Yelos, D.; Yoshida, A.; Yoshida, T.; Yoshikoshi, T.; Zabalza, V.; Zacharias, M.; Zajczyk, A.; Zanin, R.; Zdziarski, A.; Zech, A.; Zhao, A.; Zhou, X.; Ziętara, K.; Ziolkowski, J.; Ziółkowski, P.; Zitelli, V.; Zurbach, C.; Żychowski, P.; CTA Consortium

    2013-03-01

    The Cherenkov Telescope Array (CTA) is a new observatory for very high-energy (VHE) gamma rays. CTA has ambitions science goals, for which it is necessary to achieve full-sky coverage, to improve the sensitivity by about an order of magnitude, to span about four decades of energy, from a few tens of GeV to above 100 TeV with enhanced angular and energy resolutions over existing VHE gamma-ray observatories. An international collaboration has formed with more than 1000 members from 27 countries in Europe, Asia, Africa and North and South America. In 2010 the CTA Consortium completed a Design Study and started a three-year Preparatory Phase which leads to production readiness of CTA in 2014. In this paper we introduce the science goals and the concept of CTA, and provide an overview of the project.

  6. Mexico introduces pentavalent vaccine.

    Science.gov (United States)

    1999-08-01

    Combination vaccines have been introduced in Mexico. The national immunization program has incorporated the measles-mumps-rubella (MMR) vaccines in 1998, and the pentavalent vaccine in 1999. The two categories of antigen composition in combination vaccines are: 1) multiple different antigenic types of a single pathogen, such as the 23 valent pneumococcal polysaccharide vaccine, and 2) antigens from different pathogens causing different diseases, such as the DPT and MMR vaccines. Pentavalent vaccines are included in the second category. The vaccine protects against diphtheria, tetanus, pertussis, hepatitis B, and other diseases produced by Haemophilus influenzae type b (Hib). Combined diphtheria, tetanus, pertussis, hepatitis B, and Haemophilus influenza type b (DTP-HB/Hib) vaccine has been distributed to 87% of Mexican children under 1 year of age. Over 800,000 doses of pentavalent vaccine have been administered.

  7. Batch anaerobic methanogenesis of phenolic coal conversion waste water

    Energy Technology Data Exchange (ETDEWEB)

    Fedorak, P.M.; Hrudey, S.E.

    1985-01-01

    The amenability to anaerobic treatment of a phenolic wastewater from a coal conversion pilot plant was investigated in batch experiments using the Hungate serum bottle technique, using cultures containing unmodified wastewater, wastewater extracted with ether, and pre-reduced, reconstituted wastewater. Data are given on the composition of the wastewater and the concentrations of various phenolic compounds present. Wastewater concentrations of 2, 4 and 6% (vol/vol) increased methane production compared with control cultures, but higher concentrations of the wastewater were inhibitory. Further experiments indicated that the inhibitory components were ether-extractable, but were not any of the major phenolic compounds present in the original wastewater. There was also evidence to confirm that m-cresol was amenable to anaerobic degradation.

  8. BIODEGRADATION OF PHENOL BY FREE AND IMMOBILIZED CELLS OF A NOVEL Pseudomonas sp. NBM11

    Directory of Open Access Journals (Sweden)

    Satya Sundar Mohanty

    Full Text Available Abstract In the present study, a pure culture of bacterium (Pseudomonas sp. Strain NBM11 was isolated from the soil sample from a site contaminated with medical wastes and wastewater. The isolated strain can degrade up to 1000 mg/L of phenol completely. It was observed that temperature, pH and initial concentration of phenol play key roles in determining the rate of phenol degradation. The isolated strain exhibited the maximal degradation of the substrate within a range of pH 6.8 to 7.2 and an incubation temperature between 30 ºC and 32 ºC. It was found that by increasing the concentration of phenol, the lag phase gets extended due to the inhibitory nature of phenol. The kinetic parameters such as µmax (maximum specific growth rate, Ks (half-saturation coefficient and Ki (substrate inhibition constant were estimated as 0.184 1/h, 7.79 mg/L and 319.24 mg/L, respectively, by fitting the growth kinetics data to the Haldane model of substrate inhibition. The bacterial strain was immobilized in alginate beads and its phenol degradation efficiency was observed to increase many fold. The immobilized cells were found to be used efficiently for seven cycles consecutively without any decrease in their efficiency.

  9. Introducing International Geneva

    CERN Multimedia

    2015-01-01

    Geneva is variously known as the city of peace, the world’s smallest metropolis and a place where great ideas have taken form. It has been the home to philosophers such as Rousseau and Voltaire. It was the centre of the Calvinist reformation and birthplace of the Red Cross.   I hardly need to tell you that it is also a city of great international collaboration in science. Little wonder, then, that over the years, Geneva has developed into the world’s capital of internationalism in the broadest sense of the word. Yet while we all know of the existence of modern day International Geneva, how many of us really know what it does? Here at CERN, we’re about to find out. Next week sees the first in a series of talks at the Laboratory from the heads of some of the institutions that make up International Geneva. On Friday, 20 February, it will be my pleasure to introduce you to Michael Møller, Acting Director-General of the United Nations Office at Geneva (UNO...

  10. Introducing the new EDMS

    CERN Multimedia

    The EDMS Team

    2014-01-01

    We are very pleased to announce the arrival of a brand new EDMS: EDMS 6. The CERN Engineering and Equipment Data Management Service just got better than ever! EDMS is the de facto interface for all engineering related data and more. Currently there are more than 1.2 million documents and nearly 2 million files stored in EDMS.   What’s new? The first thing you will notice is the look and feel of EDMS 6; the new design not only makes it more modern but also more intuitive, so that the system is easier to use, regardless of your experience with EDMS. Whilst we have kept the key concepts, we have introduced more functionality and improved navigation within the interface, allowing for better performance to help you in your daily work. We have also added a personal slant to EDMS 6 so that you can now customise your list of favourite objects. Modifying data in EDMS is much simpler, allowing you to view all object data in a single window.  More functionality will be added in the ...

  11. Development of Simple Bacterial Biosensor for Phenol Detection in Water at Medium Concentration using Glass Microelectrode

    Directory of Open Access Journals (Sweden)

    Setyawan Purnomo Sakti

    2016-01-01

    Full Text Available Water is one of the most fundamental natural resources in earth. The availability of clean water becomes a global interest. Many human activities result in water pollution. One from many pollution substances in water is phenol. Phenol is a very common residual compound in industrial activity. Extensive use of phenol in industry degrades water quality. Regulation has been set in many countries to prevent further damage to the water resource caused by phenol and limiting phenol concentration in water before released into the environment. Therefor it is importance to develop a sensor which can detect phenol concentration in water to be used as a wastewater quality control system. This paper presents a development of bacterial biosensor using Pseudomonas putida and Pseudomonas fluorescens as a biological sensitive material. The sensor was made from glass micro electrode using Ag/AgCl electrode as reference electrode, silver electrode and cellulose ester. The Pseudomonas putida was entrapped inside the nutrient solution and separated by cellulose ester membrane from water containing phenol. It was found that the Pseudomonas putida in used must be growth in 10 hours to reach its optimum growth condition. Linear relationship between biosensor output voltages to phenol concentration was measured for phenol concentration below 200 ppm. The sensitivity of the developed biosensor was 72mV/ppm for Pseudomonas putida and 68.8 mV/ppm for Pseudomonas fluorescens.

  12. Electrochemical sensor for predicting transformer overload by phenol measurement

    Energy Technology Data Exchange (ETDEWEB)

    Bosworth, Timothy; Setford, Steven; Saini, Selwayan [Cranfield Centre for Analytical Science, Cranfield University, Silsoe, Beds MK45 4DT (United Kingdom); Heywood, Richard [National Grid Company Plc, Kelvin Avenue, Leatherhead, Surrey KT22 7ST (United Kingdom)

    2003-03-10

    Transformer overload is a significant problem to the power transmission industry, with severe safety and cost implications. Overload may be predicted by measuring phenol levels in the transformer-insulating oil, arising from the thermolytic degradation of phenol-formaldehyde resins. The development of two polyphenol oxidase (PPO) sensors, based on monitoring the enzymatic consumption of oxygen using an oxygen electrode, or reduction of enzymatically generated o-quinone at a screen-printed electrode (SPE), for the measurement of phenol in transformer oil is reported. Ex-service oils were prepared either by extraction into aqueous electrolyte-buffer, or by direct dilution in propan-2-ol, the latter method being more amenable to simple at-line operation. The oxygen electrode, with a sensitivity of 2.87 nA {mu}g{sup -1} ml{sup -1}, RSD of 7.0-19.9% and accuracy of {+-}8.3% versus the industry standard International Electrotechnical Commission (IEC) method, proved superior to the SPE (sensitivity: 3.02 nA {mu}g{sup -1} ml{sup -1}; RSD: 8.9-18.3%; accuracy: {+-}7.9%) and was considerably more accurate at low phenol concentrations. However, the SPE approach is more amenable to field-based usage for reasons of device simplicity. The method has potential as a rapid and simple screening tool for the at-site monitoring of phenol in transformer oils, thereby reducing incidences of transformer failure.

  13. Radiation induced decomposition of chlorinated phenols in water

    Science.gov (United States)

    Getoff, N.; Solar, S.

    Experiments with 4-Cl-phenol as a model compound for pesticides were performed under steady-state conditions using deoxygenated solutions as well as such saturated with air, oxygen or oxygen mixed with ozone. The yield of Cl -ions serviced as an indicator for the degradation process. As main products of the first step of decomposition were identified: polyhydroxybenzenes, aldehydes and acids. The yield of aldehydes was studied as a function of the absorbed dose and substrate concentration. In the presence of ozone a chain-reaction of the oxidative pollutant degradation takes place. Transient absorption spectra and kinetics obtained by preliminary pulse radiolysis studies of 4-Cl-phenol in the presence of oxygen as well as probable reaction mechanisms are also presented.

  14. Recovery of phenol of industrial wastewaters with NaCl treatment

    International Nuclear Information System (INIS)

    Serna, Iveth; Torres, Jesus; Hoyos Bibian

    2003-01-01

    A technique for phenol recovery from residual wastewater, which has been made in an empiric way in some local industries, is explored in this work. It was carried out an experimental design that takes into account the concentration of NaCl as the entrance variable and the phenol recovery percentage as the exit variable. The statistical analysis of data determined that the best operation point is 25 Celsius degrade, with a initial ph between 2 and 3, an initial concentration of 6% and 21,5% for phenol and NaCl respectively, achieving a phenol recovery of 79 % with a phenol concentration in the organic phase of 83%. Besides the experimental part some theories are exposed dealing with the separation of a no electrolyte and water by salt addition

  15. Effect of operational strategies on activated sludge’s acclimation to phenol, subsequent aerobic granulation, and accumulation of polyhydoxyalkanoates

    International Nuclear Information System (INIS)

    Wosman, Afrida; Lu, Yuhao; Sun, Supu; Liu, Xiang; Wan, Chunli; Zhang, Yi; Lee, Duu-Jong; Tay, JooHwa

    2016-01-01

    Highlights: • Activated sludge was acclimated to phenol with 2 different strategies. • Acclimated sludge later underwent aerobic granulation process. • Sludge acclimated with phenol only degraded phenol and formed granules faster. • Sludge acclimated with phenol + acetate formed more stable and robust granules. • Both sludge exhibited significant PHA accumulation in early granulation stage. - Abstract: Aerobic granules, a relative novel form of microbial aggregate, are capable of degrading many toxic organic pollutants. Appropriate strategy is needed to acclimate seed sludge to the toxic compounds for successful granulation. In this study, two distinct strategies, i.e. mixed or single carbon sources, were experimented to obtain phenol-acclimated sludge. Their effects on reactor performance, biomass characteristics, microbial population and the granulation process were analyzed. Sludge fed with phenol alone exhibited faster acclimation and earlier appearance of granules, but possibly lower microbial diversity and reactor stability. Using a mixture of acetate and phenol in the acclimation stage, on the other hand, led to a reactor with slower phenol degradation and granulation, but eventual formation of strong and stable aerobic granules. In addition, the content of intracellular polyhydoxyakanoates (PHA) was also monitored, and significant accumulation was observed during the pre-granulation stage, where PHA >50% of dry weight was observed in both reactors.

  16. Effect of operational strategies on activated sludge’s acclimation to phenol, subsequent aerobic granulation, and accumulation of polyhydoxyalkanoates

    Energy Technology Data Exchange (ETDEWEB)

    Wosman, Afrida; Lu, Yuhao; Sun, Supu; Liu, Xiang [Department of Environmental Science and Engineering, Fudan University, 220 Handan Road, Yangpu District, Shanghai, 200433 (China); Wan, Chunli, E-mail: hitwan@163.com [Department of Environmental Science and Engineering, Fudan University, 220 Handan Road, Yangpu District, Shanghai, 200433 (China); Zhang, Yi, E-mail: sybil_zhang@yahoo.com [Department of Environmental Science and Engineering, Fudan University, 220 Handan Road, Yangpu District, Shanghai, 200433 (China); Lee, Duu-Jong [Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan (China); Tay, JooHwa [Department of Civil Engineering, University of Calgary, Calgary, AB T2N 1N4 (Canada)

    2016-11-05

    Highlights: • Activated sludge was acclimated to phenol with 2 different strategies. • Acclimated sludge later underwent aerobic granulation process. • Sludge acclimated with phenol only degraded phenol and formed granules faster. • Sludge acclimated with phenol + acetate formed more stable and robust granules. • Both sludge exhibited significant PHA accumulation in early granulation stage. - Abstract: Aerobic granules, a relative novel form of microbial aggregate, are capable of degrading many toxic organic pollutants. Appropriate strategy is needed to acclimate seed sludge to the toxic compounds for successful granulation. In this study, two distinct strategies, i.e. mixed or single carbon sources, were experimented to obtain phenol-acclimated sludge. Their effects on reactor performance, biomass characteristics, microbial population and the granulation process were analyzed. Sludge fed with phenol alone exhibited faster acclimation and earlier appearance of granules, but possibly lower microbial diversity and reactor stability. Using a mixture of acetate and phenol in the acclimation stage, on the other hand, led to a reactor with slower phenol degradation and granulation, but eventual formation of strong and stable aerobic granules. In addition, the content of intracellular polyhydoxyakanoates (PHA) was also monitored, and significant accumulation was observed during the pre-granulation stage, where PHA >50% of dry weight was observed in both reactors.

  17. Bioavailability of phenols from a phenol-enriched olive oil.

    Science.gov (United States)

    Suárez, Manuel; Valls, Rosa M; Romero, Maria-Paz; Macià, Alba; Fernández, Sara; Giralt, Montse; Solà, Rosa; Motilva, Maria-José

    2011-12-01

    Phenolic compounds are one of the main reasons behind the healthy properties of virgin olive oil (VOO). However, their daily intake from VOO is low compared with that obtained from other phenolic sources. Therefore, the intake of VOO enriched with its own phenolic compounds could be of interest to increase the daily dose of these beneficial compounds. To evaluate the effectiveness of enrichment on their bioavailability, the concentration of phenolic compounds and their metabolites in human plasma (0, 60, 120, 240 and 300 min) from thirteen healthy volunteers (seven men and six women, aged 25 and 69 years) was determined after the ingestion of a single dose (30 ml) of either enriched virgin olive oil (EVOO) (961·17 mg/kg oil) or control VOO (288·89 mg/kg oil) in a cross-over study. Compared with VOO, EVOO increased plasma concentration of the phenol metabolites, particularly hydroxytyrosol sulphate and vanillin sulphate (P oil phenols are highly dependent on the individual.

  18. Optimization of phenol biodegradation by efficient bacteria isolated from petrochemical effluents

    Directory of Open Access Journals (Sweden)

    M. Shahriari Moghadam

    2016-05-01

    Full Text Available Phenol is an environmental pollutant present in industrial wastewaters such as refineries, coal processing and petrochemicals products. In this study three phenol degrading bacteria from Arak Petrochemical Complex effluent were isolated which consume phenol. Molecular analysis was used to identify bacteria and isolated bacteria were identified as Rhodococcus pyridinivorans (NS1, Advenella faeciporci (NS2 and Pseudomonas aeroginosa (NS3. Among the isolated strains, NS1 had the highest ability to degrade phenol. In order to observe the best yield in phenol biodegradation using NS1, optimization was performed using one factor at a time of experimental design to investigate the effect of four factors, including pH, temperature, phosphate and urea concentration. The optimal biodegradation condition through or tho pathway was pH = 8, urea = 1 g/L, temperature = 30°C and K2HPO4 = 0.5 g/L. Under the suggested condition, a biodegradation efficiency of 100% was achieved. Moreover, NS1 has shown growth and phenol degradation in concentrations between 250 to 2000 mg/L. In a nutshell, the results revealed thatphenol efficiently consumed by NS1 as the sole carbon source. Obviously, the isolate strain may be seen as an important tool in the bioremediation of wastewater effluent, petrochemical complex.

  19. Phenol-photodegradation on ZrO2. Enhancement by semiconductors.

    Science.gov (United States)

    Karunakaran, C; Dhanalakshmi, R; Gomathisankar, P

    2012-06-15

    On illumination with light of wavelength 365 nm phenol undergoes degradation on the surface of ZrO(2). The rate of degradation enhances linearly with the concentration of phenol and also the light intensity but decreases with increase of pH. The photonic efficiency of degradation is higher with illumination at 254 nm than with 365 nm. The diffuse reflectance spectral study suggests phenol-sensitized activation of ZrO(2) with 365 nm light. TiO(2), Fe(2)O(3), CuO, ZnO, ZnS, Nb(2)O(5) and CdO particles enhance the photodegradation on ZrO(2), indicating inter-particle charge-transfer. Determination of size of the particles under suspension, by light scattering technique, shows agglomeration of particles supporting the proposition of charge-transfer between particles. Copyright © 2012 Elsevier B.V. All rights reserved.

  20. Sinalbin degradation products in mild yellow mustard paste

    Directory of Open Access Journals (Sweden)

    Paunović Dragana

    2012-01-01

    Full Text Available Sinalbin degradation products in mild yellow mustard paste were investigated. The analyzed material consisted of a mild yellow mustard paste condiment and ground white mustard seeds which were originally used in the mustard paste production process. The samples were extracted in a Soxhlet extraction system and analyzed by gas chromatography - mass spectrometry (GC-MS technique. The only sinalbin degradation product in ground mustard seeds was 2-(4-hydroxyphenylacetonitrile. The most abundant sinalbin degradation product in yellow mustard paste was 4-(hydroxymethylphenol. Other compounds identified in this sample were: 4-methyl phenol, 4-ethyl phenol, 4-(2-hydroxyethylphenol and 2-(4-hydroxyphenyl ethanoic acid.

  1. Influence of physical and chemical parameters on the irradiation of aqueous solutions of phenol by electron beam

    International Nuclear Information System (INIS)

    Pellizzari, Fabien

    2005-01-01

    The aim of this work was the study of the influence of different parameters by electron beam irradiation on the decomposition of phenol in aqueous solution. A simulation based on a simplified mechanism emphasized the importance of the oxygenation of the solutions in the removal of phenol by ionisation. A model of the reactor used was proposed from the study of the influence of the beam energy on the decomposition of phenol. Penetration depths of the electrons were determined. Phenol degradation was found to increase with the dose rate. The fraction of the dose into several passages under the electron beam improved the abatement of the phenol. The reoxygenation of the solutions between each passage and the kinetic expressions of irradiation could explain this effect. As expected, the first by-products identified were originated from the reaction of phenol with hydroxyl radicals. [fr

  2. Biodegradation of low concentrations of 1,2-dibromoethane in groundwater is enhanced by phenol.

    Science.gov (United States)

    Baek, Kyunghwa; Wang, Meng; McKeever, Robert; Rieber, Kahlil; Park, Chul; Nüsslein, Klaus

    2014-02-01

    The lead scavenger 1,2-dibromoethane (EDB), a former additive to leaded gasoline, is a common groundwater contaminant, yet not much knowledge is available for its targeted bioremediation, especially under in situ conditions. The study site was an aviation gas spill site, which, although all hydrocarbons and most of the EDB were remediated in the mid-1990s, still exhibits low levels of EDB remaining in the groundwater (about 11 μg EDB/l). To evaluate the effect of phenol on biostimulation of low concentration of EDB, microcosms were established from an EDB-contaminated aquifer. After 300 days at environmentally relevant conditions (12 ± 2 °C, static incubation), EDB was not significantly removed from unamended microcosms compared to the abiotic control. However, in treatments amended with phenol, up to 80 % of the initial EDB concentration had been degraded, while added phenol was removed completely. Microbial community composition in unamended and phenol-amended microcosms remained unchanged, and Polaromonas sp. dominated both types of microcosms, but total bacterial abundance and numbers of the gene for phenol hydroxylase were higher in phenol-amended microcosms. Dehalogenase, an indicator suggesting targeted aerobic biodegradation of EDB, was not detected in either treatment. This finding suggests phenol hydroxylase, rather than a dehalogenation reaction, may be responsible for 1,2-dibromoethane oxidation under in situ conditions. In addition, biostimulation of EDB is possible through the addition of low levels of phenol in aerobic groundwater sites.

  3. Hydroxyl radical mediated degradation of phenylarsonic acid.

    Science.gov (United States)

    Xu, Tielian; Kamat, Prashant V; Joshi, Sachin; Mebel, Alexander M; Cai, Yong; O'Shea, Kevin E

    2007-08-16

    Phenyl-substituted arsonic acids have been widely used as feed additives in the poultry industry. While very few studies have been reported on the environmental impact of these compounds, they have been introduced into the environment through land application of poultry litter in large quantities (about 10(6) kg/year). Phenylarsonic acid (PA) was used as a model for problematic arsonic acids. Dilute aqueous solutions of PA were subjected to gamma radiolysis under hydroxyl radical generating conditions, which showed rapid degradation of PA. Product studies indicate addition of (.)OH to the phenyl ring forms the corresponding phenols as the primary products. Arsenite, H3As(III)O3, and arsenate, H3As(V)O4, were also identified as products. The optimized structures and relative calculated energies (using GAUSSIAN 98, the B3LYP/6-31G(d) method) of the various transient intermediates are consistent with the product studies. Pulse radiolysis was used to determine the rate constants of PA with (.)OH (k = 3.2 x 10(9) M(-1) s(-1)) and SO4(.-) (k = 1.0 x 10(9) M(-1) s(-1)). PA reacts slower toward O(.-) (k = 1.9 x 10(7) M(-1) s(-1)) and N3(.) (no detectable transient), due to the lower oxidation potential of these two radicals. Our results indicate advanced oxidative processes employing (.)OH and SO4(.-) can be effective for the remediation of phenyl-substituted arsonic acids.

  4. Soymilk enriched with green coffee phenolics - Antioxidant and nutritional properties in the light of phenolics-food matrix interactions.

    Science.gov (United States)

    Sęczyk, Łukasz; Świeca, Michał; Gawlik-Dziki, Urszula

    2017-05-15

    This study investigated the effect of soymilk fortification with green coffee extract (GCE) on phenolic contents, antioxidant capacity, relative in vitro digestibility of proteins and starch, and consumer acceptance. Special attention was paid to the effect of phenolics-food matrix interactions on fortification efficiency. Soymilk was enriched with GCE extracts containing 0.025-1mg of phenolics per 1mL-samples M1-M6. Compared to control, an increase in phenolic contents of up to 70% (M6) was observed for potentially bioaccessible fractions (AD). The antiradical activity and reducing power were also about 1.9 and 10.1 times higher, respectively. However, the determined phenolic and antioxidant activities differed from those predicted. Fortification improved the digestibility of nutrients when higher doses of GCE was introduced (M4-M6). The addition of GCE at an adequate dose allowed the production of a beverage with elevated hedonic properties. In conclusion, fortification was a successful in improving the pro-health status of soymilk. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Aquatic pathways model to predict the fate of phenolic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Aaberg, R.L.; Peloquin, R.A.; Strenge, D.L.; Mellinger, P.J.

    1983-04-01

    Organic materials released from energy-related activities could affect human health and the environment. To better assess possible impacts, we developed a model to predict the fate of spills or discharges of pollutants into flowing or static bodies of fresh water. A computer code, Aquatic Pathways Model (APM), was written to implement the model. The computer programs use compartmental analysis to simulate aquatic ecosystems. The APM estimates the concentrations of chemicals in fish tissue, water and sediment, and is therefore useful for assessing exposure to humans through aquatic pathways. The APM will consider any aquatic pathway for which the user has transport data. Additionally, APM will estimate transport rates from physical and chemical properties of chemicals between several key compartments. The major pathways considered are biodegradation, fish and sediment uptake, photolysis, and evaporation. The model has been implemented with parameters for distribution of phenols, an important class of compounds found in the water-soluble fractions of coal liquids. Current modeling efforts show that, in comparison with many pesticides and polyaromatic hydrocarbons (PAH), the lighter phenolics (the cresols) are not persistent in the environment. The properties of heavier molecular weight phenolics (indanols, naphthols) are not well enough understood at this time to make similar judgements. For the twelve phenolics studied, biodegradation appears to be the major pathway for elimination from aquatic environments. A pond system simulation (using APM) of a spill of solvent refined coal (SRC-II) materials indicates that phenol, cresols, and other single cyclic phenolics are degraded to 16 to 25 percent of their original concentrations within 30 hours. Adsorption of these compounds into sediments and accumulation by fish was minor.

  6. Dietary phenolics: chemistry, bioavailability and effects on health.

    Science.gov (United States)

    Crozier, Alan; Jaganath, Indu B; Clifford, Michael N

    2009-08-01

    There is much epidemiological evidence that diets rich in fruit and vegetables can reduce the incidence of non-communicable diseases such as cardiovascular diseases, diabetes, cancer and stroke. These protective effects are attributed, in part, to phenolic secondary metabolites. This review summarizes the chemistry, biosynthesis and occurrence of the compounds involved, namely the C6-C3-C6 flavonoids-anthocyanins, dihydrochalcones, flavan-3-ols, flavanones, flavones, flavonols and isoflavones. It also includes tannins, phenolic acids, hydroxycinnamates and stilbenes and the transformation of plant phenols associated with food processing (for example, production of black tea, roasted coffee and matured wines), these latter often being the major dietary sources. Events that occur following ingestion are discussed, in particular, the deglycosylation, glucuronidation, sulfation and methylation steps that occur at various points during passage through the wall of the small intestine into the circulatory system and subsequent transport to the liver in the portal vein.We also summarise the fate of compounds that are not absorbed in the small intestine, but which pass into the large intestine where they are degraded by the colonic microflora to phenolic acids, which can be absorbed into the circulatory system and subjected to phase II metabolism prior to excretion. Initially, the protective effect of dietary phenolics was thought to be due to their antioxidant properties which resulted in a lowering of the levels of free radicals within the body.However, there is now emerging evidence that themetabolites of dietary phenolics,which appear in the circulatory systemin nmol/L to low mmol/L concentrations, exertmodulatory effects in cells through selective actions on different components of the intracellular signalling cascades vital for cellular functions such as growth, proliferation and apoptosis. In addition, the intracellular concentrations required to affect cell

  7. Sulfomethylated phenolic material useful in post primary oil recovery

    Energy Technology Data Exchange (ETDEWEB)

    Stapp, P.R.; Pardue, J.E.

    1986-12-30

    This patent describes a sulfomethylated alkyl phenol compound chosen from among the group consisting of sulfomethylated alkyl phenol, sulfomethylated alkylated bis-phenol, and sulfomethylated alkylated naphthol.

  8. FRUCTOSANS AND PHENOLIC COMPOUNDS OF YACON

    Directory of Open Access Journals (Sweden)

    M. S. Gins

    2015-01-01

    Full Text Available Using the high-efficiency liquid chromatography, the phenolic compounds of yacon (Polymnia sonchifolia introduced in Ukraine have been studied. The derivants of hydroxycinnamic acid is prevalent in the ethanol extracts from leaves and roots of yacon. Differences in the contents of  ethanol extracts from fresh and dry roots were shown. The total amount of hydroxycinnamic acids was 2,8 % – 4,3 % depending on the layer of leaves. It was found that roots content 36-45% of fructosans expressed as fructose and dry matter.

  9. Characterization of degradation products from alkaline wet oxidation of wheat straw

    DEFF Research Database (Denmark)

    Klinke, H.B.; Ahring, B.K.; Schmidt, A.S.

    2002-01-01

    constituted the majority of degradation products (8.5 g). The main phenol monomers were 4-hydroxybenzaldehyde, vanillin, syringaldehyde, acetosyringone (4-hydroxy-3,5-dimethoxy-acetophenone), vanillic acid and syringic acid, occurring in 0.04-0.12 g per 100 g straw concentrations. High lignin removal from...... the solid fraction (62%) did not provide a corresponding increase in the phenol monomer content but was correlated to high carboxylic acid concentrations. The degradation products in the hemicellulose fractions co-varied with the pre-treatment conditions in the principal component analysis according...... to their chemical structure, e.g. diacids (oxalic and succinic acids), furan aldehydes, phenol aldehydes, phenol ketones and phenol acids. Aromatic aldehyde formation was correlated to severe conditions with high temperatures and low pH. Apart from CO2 and water, carboxylic acids were the main degradation products...

  10. Development of a phenol-enriched olive oil with both its own phenolic compounds and complementary phenols from thyme.

    Science.gov (United States)

    Rubió, Laura; Motilva, Maria-José; Macià, Alba; Ramo, Tomás; Romero, Maria-Paz

    2012-03-28

    Besides affecting the oil's sensorial characteristics, the presence of herbs and spices has an impact on the nutritional value of the flavored oils. The aim of the study was to develop a new product based on the phenol-enrichment of a virgin olive oil with both its own phenolic compounds (secoiridoid derivatives) plus additional complementary phenols from thyme (flavonoids). We studied the effect of the addition of phenolic extracts (olive cake and thyme) on phenolic composition, oxidative stability, antioxidant activity, and bitter sensory attribute of olive oils. Results showed that flavonoids from thyme appeared to have higher transference ratios (average 89.7%) from the phenolic extract to oil, whereas secoiridoids from olive presented lower transference ratios (average 35.3%). The bitter sensory attribute of the phenol-enriched oils diminished with an increase of the concentration of phenols from thyme, which might denote an improvement in the consumer acceptance.

  11. Phenolic Profiling for Traceability of Vanilla ×tahitensis

    Science.gov (United States)

    Busconi, Matteo; Lucini, Luigi; Soffritti, Giovanna; Bernardi, Jamila; Bernardo, Letizia; Brunschwig, Christel; Lepers-Andrzejewski, Sandra; Raharivelomanana, Phila; Fernandez, Jose A.

    2017-01-01

    Vanilla is a flavoring recovered from the cured beans of the orchid genus Vanilla. Vanilla ×tahitensis is traditionally cultivated on the islands of French Polynesia, where vanilla vines were first introduced during the nineteenth century and, since the 1960s, have been introduced to other Pacific countries such as Papua New Guinea (PNG), cultivated and sold as “Tahitian vanilla,” although both sensory properties and aspect are different. From an economic point of view, it is important to ensure V. ×tahitensis traceability and to guarantee that the marketed product is part of the future protected designation of the origin “Tahitian vanilla” (PDO), currently in progress in French Polynesia. The application of metabolomics, allowing the detection and simultaneous analysis of hundreds or thousands of metabolites from different matrices, has recently gained high interest in food traceability. Here, metabolomics analysis of phenolic compounds profiles was successfully applied for the first time to V. ×tahitensis to deepen our knowledge of vanilla metabolome, focusing on phenolics compounds, for traceability purposes. Phenolics were screened through a quadrupole-time-of-flight mass spectrometer coupled to a UHPLC liquid chromatography system, and 260 different compounds were clearly evidenced and subjected to different statistical analysis in order to enable the discrimination of the samples based on their origin. Eighty-eight and twenty three compounds, with a prevalence of flavonoids, resulted to be highly discriminant through ANOVA and Orthogonal Projections to Latent Structures Discriminant Analysis (OPLS-DA) respectively. Volcano plot analysis and pairwise comparisons were carried out to determine those compounds, mainly responsible for the differences among samples as a consequence of either origin or cultivar. The samples from PNG were clearly different from the Tahitian samples that were further divided in two different groups based on the different

  12. Phenolic Profiling for Traceability of Vanilla ×tahitensis

    Directory of Open Access Journals (Sweden)

    Matteo Busconi

    2017-10-01

    Full Text Available Vanilla is a flavoring recovered from the cured beans of the orchid genus Vanilla. Vanilla ×tahitensis is traditionally cultivated on the islands of French Polynesia, where vanilla vines were first introduced during the nineteenth century and, since the 1960s, have been introduced to other Pacific countries such as Papua New Guinea (PNG, cultivated and sold as “Tahitian vanilla,” although both sensory properties and aspect are different. From an economic point of view, it is important to ensure V. ×tahitensis traceability and to guarantee that the marketed product is part of the future protected designation of the origin “Tahitian vanilla” (PDO, currently in progress in French Polynesia. The application of metabolomics, allowing the detection and simultaneous analysis of hundreds or thousands of metabolites from different matrices, has recently gained high interest in food traceability. Here, metabolomics analysis of phenolic compounds profiles was successfully applied for the first time to V. ×tahitensis to deepen our knowledge of vanilla metabolome, focusing on phenolics compounds, for traceability purposes. Phenolics were screened through a quadrupole-time-of-flight mass spectrometer coupled to a UHPLC liquid chromatography system, and 260 different compounds were clearly evidenced and subjected to different statistical analysis in order to enable the discrimination of the samples based on their origin. Eighty-eight and twenty three compounds, with a prevalence of flavonoids, resulted to be highly discriminant through ANOVA and Orthogonal Projections to Latent Structures Discriminant Analysis (OPLS-DA respectively. Volcano plot analysis and pairwise comparisons were carried out to determine those compounds, mainly responsible for the differences among samples as a consequence of either origin or cultivar. The samples from PNG were clearly different from the Tahitian samples that were further divided in two different groups based on

  13. Phenolic Profiling for Traceability of Vanilla ×tahitensis.

    Science.gov (United States)

    Busconi, Matteo; Lucini, Luigi; Soffritti, Giovanna; Bernardi, Jamila; Bernardo, Letizia; Brunschwig, Christel; Lepers-Andrzejewski, Sandra; Raharivelomanana, Phila; Fernandez, Jose A

    2017-01-01

    Vanilla is a flavoring recovered from the cured beans of the orchid genus Vanilla . Vanilla × tahitensis is traditionally cultivated on the islands of French Polynesia, where vanilla vines were first introduced during the nineteenth century and, since the 1960s, have been introduced to other Pacific countries such as Papua New Guinea (PNG), cultivated and sold as "Tahitian vanilla," although both sensory properties and aspect are different. From an economic point of view, it is important to ensure V . × tahitensis traceability and to guarantee that the marketed product is part of the future protected designation of the origin "Tahitian vanilla" (PDO), currently in progress in French Polynesia. The application of metabolomics, allowing the detection and simultaneous analysis of hundreds or thousands of metabolites from different matrices, has recently gained high interest in food traceability. Here, metabolomics analysis of phenolic compounds profiles was successfully applied for the first time to V . × tahitensis to deepen our knowledge of vanilla metabolome, focusing on phenolics compounds, for traceability purposes. Phenolics were screened through a quadrupole-time-of-flight mass spectrometer coupled to a UHPLC liquid chromatography system, and 260 different compounds were clearly evidenced and subjected to different statistical analysis in order to enable the discrimination of the samples based on their origin. Eighty-eight and twenty three compounds, with a prevalence of flavonoids, resulted to be highly discriminant through ANOVA and Orthogonal Projections to Latent Structures Discriminant Analysis (OPLS-DA) respectively. Volcano plot analysis and pairwise comparisons were carried out to determine those compounds, mainly responsible for the differences among samples as a consequence of either origin or cultivar. The samples from PNG were clearly different from the Tahitian samples that were further divided in two different groups based on the different

  14. Irradiation with benzene, toluene and phenol electron beams in aqueous solution

    International Nuclear Information System (INIS)

    Santoyo O, E.L.; Lopez V, H.; Vazquez A, O.; Lizama S, B.E.; Garcia F, M.

    1998-01-01

    It is described a methodology for waste water treatment which is simulated doing a benzene-toluene-phenol mixture in aqueous solution. Three different concentrations of them ones were used which were irradiated with electron beams coming from a Pelletron Accelerator carrying out the degradation effect of these compounds in CO 2 and H 2 O. By mean of gas chromatography the analytical determinations were realized finding that in lower concentration of benzene and toluene performances of degradation higher than 95 % were obtained, but higher concentrations (100 ppm) the performance diminishes at 89 %, while for phenol in higher concentrations its degradation is over 60 % and in lower concentrations the degradation is under 80 %. The results are obtained with a constant irradiation time of 12 seconds and neutral pH. (Author

  15. Ranking of phenols for abiotic oxidation in aqueous environment: a QSPR approach.

    Science.gov (United States)

    Gramatica, Paola; Pilutti, Pamela; Papa, Ester

    2005-01-01

    The limited availability and variability of data related to the overall degradation of compounds in the environment is a very relevant issue in studies related to environmental fate and chemical behavior. The studied phenol data set consists of reaction rate constants of different oxidation reactions in surface waters, available either experimentally or, to fill the data gap, from our QSAR models reported herein. A PCA (Principal Component Analysis) model based on these oxidative degradations has been proposed to evaluate the degradability of chemicals. The score of the first Principal Component is modelled by theoretical molecular descriptors to obtain a multiple linear regression (MLR) model with high predictive power, both internally and externally validated. This modeling approach allows a fast and preliminary ranking of phenols according to their tendency to be degraded by oxidants in water, starting only from knowledge of their molecular structure.

  16. Assessing wines based on total phenols, phenolic acids and ...

    African Journals Online (AJOL)

    The aim of this study was to investigate the phenolic profile of some red wines produced from native Turkish grape varieties (Vitis vinifera Öküzgözü, V. vinifera Boğazkere and V. vinifera Shiraz) and some red fruit wines produced from pomegranate (Punica granatum L.), myrtle (Myrtus communis L.) and black mulberry ...

  17. Characterization of phenolic resins with thermogravimetry-mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Cherng; Tackett, J.R.

    1990-01-01

    As part of an advanced material research program, thermogravimetry-mass spectrometry (TG-MS) analysis of a phenolic resin was carried out recently for the study of the curing of the prepolymer, solvent extraction, and carbonization of the polymer at high temperature in inert atmosphere. These steps are critical to the quality of the produced advanced material. In addition to TG-MS, several other complementary techniques were also employed for the analysis of the phenolic resin prepolymer and its curing and thermal degradation products. These techniques include pyrolysis-gas chromatography-mass spectrometry, direct insertion probe-mass spectrometry and gas chromatography-mass spectrometry. 7 refs., 5 figs., 3 tabs.

  18. Phenolic Acid-based Poly(anhydride-esters) as Antioxidant Biomaterials.

    Science.gov (United States)

    Prudencio, Almudena; Faig, Jonathan J; Song, MinJung; Uhrich, Kathryn E

    2016-02-01

    Poly(anhydride-esters) comprised of naturally occurring, non-toxic phenolic acids, namely syringic and vanillic acid, with antioxidant properties were prepared via solution polymerization methods. Polymer and polymer precursor physiochemical properties were characterized, including polymer molecular weight and thermal properties. In vitro release studies illustrated that polymer hydrolytic degradation was influenced by relative hydrophobicity and degree of methoxy substitution of the phenolic acids. Further, the released phenolic acids were found to maintain antioxidant potency relative to free phenolic acid controls as determined by a 2,2-diphenyl-1-picrylhydrazyl assay. Polymer cytotoxicity was assessed with L929 fibroblasts in polymer-containing media; appropriate cell morphology and high fibroblast proliferation were obtained for the polymers at the lower concentrations. These polymers deliver non-cytotoxic levels of naturally occurring antioxidants, which could be efficacious in topical delivery of antioxidant therapies. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Phenolic acid-based poly(anhydride-esters) as antioxidant biomaterialsa

    Science.gov (United States)

    Prudencio, Almudena; Faig, Jonathan J.; Song, MinJung

    2015-01-01

    Poly(anhydride-esters) comprised of naturally occurring, non-toxic phenolic acids, namely syringic and vanillic acid, with antioxidant properties were prepared via solution polymerization methods. Polymer and polymer precursor physiochemical properties were characterized, including polymer molecular weight and thermal properties. In vitro release studies illustrated that polymer hydrolytic degradation was influenced by relative hydrophobicity and degree of methoxy substitution of the phenolic acids. Further, the released phenolic acids were found to maintain antioxidant potency relative to free phenolic acid controls as determined by a 2,2-diphenyl-1-picrylhydrazyl assay. Polymer cytotoxicity was assessed with L929 fibroblasts in polymer-containing media; appropriate cell morphology and high fibroblast proliferation were obtained for the polymers at the lower concentrations. These polymers deliver non-cytotoxic levels of naturally occurring antioxidants, which could be efficacious in topical delivery of antioxidant therapies. PMID:26425923

  20. Thermal stability of phenolic based binders and frictional performance of brake composite materials

    Science.gov (United States)

    Pudhota, Madhuri

    To enhance frictional performance, wear and to obtain improved thermal stability with a reduction of noise, vibration, and harshness (NVH) and provide environment friendly brakes for the increasing needs of the population's comfort and safety requirements this study was initiated. The thermal stability of two different phenolic resins as binder on the frictional performance of brake composite material was studied. The two phenolic resins used are Durite phenolic resin and Bakelite phenolic resins. They were tested for friction, wear, thermal stability and degradation. This was executed by using a universal friction tester (UFT) for testing friction and wear, then on thermo gravimetric analysis (TGA) and the TGA results indicate more mass loss of NB samples contrary to test results. When individual materials were heated, Bakelite lost less mass compared to Durite. The friction test indicates more friction when used the NB samples but they had less wear and more stability nevertheless this could vary for other compositions and conditions.

  1. Phenol oxidation by mushroom waste extracts: a kinetic and thermodynamic study.

    Science.gov (United States)

    Pigatto, Gisele; Lodi, Alessandra; Aliakbarian, Bahar; Converti, Attilio; da Silva, Regildo Marcio Gonçalves; Palma, Mauri Sérgio Alves

    2013-09-01

    Tyrosinase activity of mushroom extracts was checked for their ability to degrade phenol. Phenol oxidation kinetics was investigated varying temperature from 10 to 60 °C and the initial values of pH, enzyme activity and phenol concentration in the ranges 4.5-8.5, 1.43-9.54 U/mL and 50-600 mg/L, respectively. Thermodynamic parameters of phenol oxidation and tyrosinase reversible inactivation were estimated. Tyrosinase thermostability was also investigated through residual activity tests after extracts exposition at 20-50 °C, whose results allowed exploring the thermodynamics of enzyme irreversible thermoinactivation. This study is the first attempt to separate the effects of reversible unfolding and irreversible denaturation of tyrosinase on its activity. Extracts were finally tested on a real oil mill wastewater. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Lipid encapsulated phenolic compounds by fluidization

    Science.gov (United States)

    Phenolic compounds exhibit antioxidant and antimicrobial activities with applications as functional food and feed additives. Ferulic acid, a phenolic compound present in grain crops and lignocellulose biomass, was encapsulated with saturated triglycerides using a laboratory fluidizer. Stability of t...

  3. Synthesis and Characterization of Bio-Oil Phenol Formaldehyde Resin Used to Fabricate Phenolic Based Materials

    Directory of Open Access Journals (Sweden)

    Yong Cui

    2017-06-01

    Full Text Available In this study, bio-oil from the fast pyrolysis of renewable biomass was used as the raw material to synthesize bio-oil phenol formaldehyde (BPF resin—a desirable resin for fabricating phenolic-based material. During the synthesis process, paraformaldehyde was used to achieve the requirement of high solid content and low viscosity. The properties of BPF resins were tested. Results indicated that BPF resin with the bio-oil addition of 20% had good performance on oxygen index and bending strength, indicating that adding bio-oil could modify the fire resistance and brittleness of PF resin. The thermal curing behavior and heat resistance of BPF resins were investigated by differential scanning calorimetry (DSC and thermal gravimetric analysis (TGA. Results showed that adding bio-oil had an impact on curing characteristics and thermal degradation process of PF resin, but the influence was insignificant when the addition was relatively low. The chemical structure and surface characteristics of BPF resins were determined by Fourier transform infrared (FTIR spectroscopy and scanning electron microscopy (SEM. The analysis demonstrated that adding bio-oil in the amount of 20% was able to improve the crosslinking degree and form more hydrocarbon chains in PF resin.

  4. Synthesis and Characterization of Bio-Oil Phenol Formaldehyde Resin Used to Fabricate Phenolic Based Materials.

    Science.gov (United States)

    Cui, Yong; Hou, Xiaopeng; Wang, Wenliang; Chang, Jianmin

    2017-06-18

    In this study, bio-oil from the fast pyrolysis of renewable biomass was used as the raw material to synthesize bio-oil phenol formaldehyde (BPF) resin-a desirable resin for fabricating phenolic-based material. During the synthesis process, paraformaldehyde was used to achieve the requirement of high solid content and low viscosity. The properties of BPF resins were tested. Results indicated that BPF resin with the bio-oil addition of 20% had good performance on oxygen index and bending strength, indicating that adding bio-oil could modify the fire resistance and brittleness of PF resin. The thermal curing behavior and heat resistance of BPF resins were investigated by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). Results showed that adding bio-oil had an impact on curing characteristics and thermal degradation process of PF resin, but the influence was insignificant when the addition was relatively low. The chemical structure and surface characteristics of BPF resins were determined by Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). The analysis demonstrated that adding bio-oil in the amount of 20% was able to improve the crosslinking degree and form more hydrocarbon chains in PF resin.

  5. Octyl Phenol Synthesis Using Natural Clays

    Directory of Open Access Journals (Sweden)

    S. Casuscelli

    2000-03-01

    Full Text Available A series of clay minerals, HB, NB and Al-PILC have been studied in the alkylation reactions of 2-octanol with phenol at 180°C, under conditions of alcohol/phenol = 1 (mole ratio and W/FAo °= 64,27 ghmol-1. The selectivity of Al-PILC was 77,12% for octyl phenol and 16,5% for dioctyl phenol.

  6. [Effects of introducing Eucalyptus on indigenous biodiversity].

    Science.gov (United States)

    Ping, Liang; Xie, Zong-Qiang

    2009-07-01

    Eucalyptus is well-known as an effective reforestation tree species, due to its fast growth and high adaptability to various environments. However, the introduction of Eucalyptus could have negative effects on the local environment, e. g., inducing soil degradation, decline of groundwater level, and decrease of biodiversity, and especially, there still have controversies on the effects of introduced Eucalyptus on the understory biodiversity of indigenous plant communities and related mechanisms. Based on a detailed analysis of the literatures at home and abroad, it was considered that the indigenous plant species in the majority of introduced Eucalyptus plantations were lesser than those in natural forests and indigenous species plantations but more than those in other exotic species plantations, mainly due to the unique eco-physiological characteristics of Eucalyptus and the irrational plantation design and harvesting techniques, among which, anthropogenic factors played leading roles. Be that as it may, the negative effects of introducing Eucalyptus on local plant biodiversity could be minimized via more rigorous scientific plantation design and management based on local plant community characteristics. To mitigate the negative effects of Eucalyptus introduction, the native trees and understory vegetation in plantations should be kept intact during reforestation with Eucalyptus to favor the normal development of plant community and regeneration. At the same time, human disturbance should be minimized to facilitate the natural regeneration of native species.

  7. Joint action of benzoxazinone derivatives and phenolic acids.

    Science.gov (United States)

    Jia, Chunhong; Jia, Chunghong; Kudsk, Per; Mathiassen, Solvejg K

    2006-02-22

    The joint action of binary and ternary mixtures of benzoxazinone derivatives and phenolic acids was studied using the additive dose model (ADM) as reference model. The activity of fixed-ratio mixtures of phenolic acids [ferulic acid (FA), p-coumaric acid (CA), vanillic acid (VA), and p-hydroxybenzoic acid (HBA)] and benzoxazinone derivatives [2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA), 6-methoxybenzoxazolin-2-one (MBOA), benzoxazolin-2-one (BOA), 2-aminophenol (AP), and N-(2-hydroxyphenyl)acetamide (HPAA)] on Lolium perenne and Myosotis arvensis root growth was assessed in Petri dishes. Root length was recorded 6 days after seeding, and EC(50) and EC(90) values were estimated using nonlinear regression analyses. The benzoxazinone derivatives were found to be more phytotoxic than the phenolic acids, particularly on M. arvensis. Binary mixtures of phenolic acids responded predominantly additively on both plant species. Deviations from additivity were species-specific with antagonistic responses on L. perenne and synergistic responses on M. arvensis. Similarly, binary mixtures of benzoxazinone derivatives also followed the ADM, although synergistic responses were observed for BOA + AP and BOA + HPAA. Binary and ternary mixtures of benzoxazinone derivatives and phenolic acids responded primarily antagonistically; however, a significant synergistic performance was observed with DIMBOA + FA and DIMBOA + VA on L. perenne. These results do not support the assumption that allelopathic effects of wheat can be attributed to synergistic effects of otherwise weakly active allelopathic compounds, and it is suggested that future research be directed toward identifying and studying the effects of other potential allelochemicals including the degradation products of the most abundant wheat allelochemicals.

  8. Phenol biodegradation by immobilized Pseudomonas putida FNCC-0071 cells in alginate beads

    Science.gov (United States)

    Hakim, Lukman Nul; Rochmadi, Sutijan

    2017-06-01

    Phenol is one of industrial liquid waste which is harmful to the environment, so it must be degraded. It can be degraded by immobilized Pseudomonas putida FNCC-0071 cells. It needs the kinetics and mass transfer data to design this process which can be estimated by the proposed dynamic model in this study. This model involves simultaneous diffusion and reaction in the alginate bead and liquid bulk. The preliminary stage of phenol biodegradation process was acclimatization cells. This is the stage where cells were acclimated to phenol as carbon source (substrate). Then the acclimated cells were immobilized in alginate beads by extrusion method. The variation of the initial phenol concentration in the solution is 350 to 850 ppm where 60 g alginate bead contained by cells loaded into its solution in reactor batch, so then biodegradation occurs. In this study, the average radius of alginate bead was 0.152 cm. The occurred kinetic reaction process can be explained by Blanch kinetic model with the decreasing of parameter μmax' while the increasing values of initial phenol concentration in the same time, but the parameters KM, KM', and kt were increasing by the rising values of initial phenol concentration. The value of the parameter β is almost zero. Effective diffusivity of phenol and cells are 1.11 × 10-5±4.5% cm2 s-1 and 1.39 × 10-7± 0.04% cm2 s-1. The partition coefficient of phenol and cells are 0.39 ± 15% and 2.22 ± 18%.

  9. Trichlorinated phenols from Hypholoma elongatum.

    NARCIS (Netherlands)

    Swarts, H.J.; Verhagen, F.J.M.; Field, J.A.; Wijnberg, J.B.P.A.

    1998-01-01

    Three trichlorinated phenols, 2,4,6-trichloro-3-methoxyphenol, 3,5,6-trichloro-2,4-dimethoxyphenol and 3,4,6-trichloro-2,5-dimethoxyphenol, were detected as novel metabolites in the ethyl acetate extract from the culture medium of the Basidiomycete, Hypholoma elongatum (strain WIJS94-28).

  10. Compositional differences in the phenolics compounds of ...

    African Journals Online (AJOL)

    This study evaluates phenolic composition of commercial and experimental wines derived from bunch (Vitis vinifera) and muscadine (Vitis rotundifolia) grapes to determine compositional differences in phenolics. HPLC analysis of wines showed that majority of phenolic compounds eluted during the first 30 min. Of the red ...

  11. PREPARATION OF NOVOLACS USING PHENOLIC RICH ...

    African Journals Online (AJOL)

    Preferred Customer

    ABSTRACT. The possibility of using phenolic rich components (water insoluble fraction) from biomass pyrolysis oil as partial substitute of phenol in synthesis of high-ortho phenolic novolac under the catalyst of. HCl/Zn(AC)2 has been proved using differential scanning calorimetry (DSC) and Fourier transformed infrared.

  12. Biodegradation of phenol using recombinant plasmid-carrying Rhodococcus erythropolis strains

    Czech Academy of Sciences Publication Activity Database

    Zídková, L.; Szököl, Juraj; Rucká, Lenka; Pátek, Miroslav; Nešvera, Jan

    2013-01-01

    Roč. 84, OCT 2013 (2013), s. 179-184 ISSN 0964-8305 R&D Projects: GA MŠk 2B08062 Institutional research plan: CEZ:AV0Z50200510 Keywords : Rhodococcus erythropolis * Phenol degradation * Wastewater Subject RIV: EE - Microbiology, Virology Impact factor: 2.235, year: 2013

  13. The role of humic and fulvic acids in the phototransformation of phenolic compounds in seawater

    Energy Technology Data Exchange (ETDEWEB)

    Calza, P., E-mail: paola.calza@unito.it; Vione, D.; Minero, C.

    2014-09-15

    Humic substances (HS) are known to act as photosensitizers toward the transformation of pollutants in the surface layer of natural waters. This study focused on the role played by HS toward the transformation of xenobiotics in seawater, with the purpose of assessing the prevailing degradation routes. Phenol was chosen as model xenobiotic and its transformation was investigated under simulated sunlight in the presence of terrestrial or marine humic and fulvic acids, in pure water at pH 8, artificial seawater (ASW) or natural seawater (NSW). The following parameters were determined: (1) the phenol degradation rate; (2) the variation in HS concentration with irradiation time; (3) the production of transformation products; (4) the influence of iron species on the transformation process. Faster transformation of phenol was observed with humic acids (HA) compared to fulvic acids (SRFA), and transformation induced by both HA and SRFA was faster in ASW than that in pure water. These observations can be explained by assuming an interplay between different competing and sometimes opposite processes, including the competition between chloride, bromide and dissolved oxygen for reaction with HS triplet states. The analysis of intermediates formed in the different matrices under study showed the formation of several hydroxylated (hydroquinone, 1,4-benzoquinone, resorcinol) and condensed compounds (2,2′-bisphenol, 4,4′-bisphenol, 4-phenoxyphenol). Although 1,4-benzoquinone was the main transformation product, formation of condensed molecules was significant with both HA and SRFA. Experiments on natural seawater spiked with HS confirmed the favored formation of condensed products, suggesting a key role of humic matter in dimerization reactions occurring in saline water. - Highlights: • Phenol transformation in seawater can be photosensitized by humic substances. • Dimeric species are peculiar intermediates formed in the process. • Phenol degradation occurred faster with

  14. Haloxylon Activated Carbon; a Novel Absorbent to Remove Phenol from Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    Miranzadeh M.B.* PhD,

    2016-09-01

    Full Text Available Abstract Aims: Even low concentrations of phenol in industrial waste can cause many difficulties for the aquatic environment. So removal of this organic matter is an important issue. the adsorption process, is one of the most effective methods for isolation and purification of Phenols. The aim of this study was to introduce wood haloxylon as a natural and new absorbent to remove phenol from aqueous solutions. Instrument & Methods: Experiments were carried out in laboratory scale to evaluate the effect of important variables such as initial pH (4, 5, 6, 7, 8 and 9, the initial concentration of phenol (100, 50 and 150mg/l, adsorbent dosage (0.5, 1 and 2g/l and reaction time (20, 40 and 60min. The concentration of phenol was measured by the photometric method at wavelengths of 500nm. Findings: The highest efficiency was recorded at pH=7 and at a rate of 45.2% and after it the removal efficiency dropped. The maximum adsorption of phenol happened in the first 20 minutes (35.8% and after that, it was absorbed more slowly and took 60 minutes (45.2% to reach the equilibrium. By increasing the concentration of phenol from 50 to 150mg/l, the removal of phenol reduced from 45.2 to 30.6% and the absorptive capacity increased of from 1.1 to 2.3mg/g. By increasing the adsorbent dosage from 0.5 to 2g/l, the removal of phenol increased from 19.1 to 45.2% and the absorptive capacity decreased from 1.9 to 1.1mg/g. Conclusion: HTAC, in optimum conditions, can be used for pre-treatment of aqueous solution containing phenol.

  15. Introduced Terrestrial Species Richness (Future)

    Data.gov (United States)

    U.S. Environmental Protection Agency — These data represent predicted current distributions of all introduced fish in the Middle-Atlantic region. These data are available for both 8-digit HUCs and EMAP...

  16. Biossensores amperométricos para determinação de compostos fenólicos em amostras de interesse ambiental Amperometric biosensors for phenolic compounds determination in the environmental interess samples

    Directory of Open Access Journals (Sweden)

    Simone Soares Rosatto

    2001-02-01

    Full Text Available Phenols are widely used in many areas and commonly found as industrial by-products. A great number of agricultural and industrial activities realise phenolic compounds in the environmental. Waste phenols are produced mainly by the wood-pulp industry and during production of synthetic polymers, drugs, plastics, dyes, pesticides and others. Phenols are also released into the environmental by the degradation of pesticides with phenolic skeleton. The phenols level control is very important for the environmental protection. Amperometric biosensor has shown the feasibility to complement laboratory-based analytical methods for the determination of phenolic compounds, providing alternatives to conventional methods which have many disadvantages. This brief review considers the evolution of an approach to amperometric measurement using the catalytic properties of some enzymes for phenolic compounds monitoring.

  17. Effect of the addition of different types of oenological commercial tannins on phenolic and sensorial red wine characteristics evolution

    Directory of Open Access Journals (Sweden)

    Jordão António M.

    2016-01-01

    Full Text Available The main objective of this work was to understand the effect of the addition of different commercial types of oenological tannins on red wine phenolic compounds and sensorial characteristics evolution. So, six different commercial oenological tannins obtained from different sources at an average dosage recommended by the manufactures were added to a red wine. During 120 wine aging days several phenolic parameters were analyzed (including several individual phenolic compounds by HPLC and also the sensorial characteristics of the wines. Wines treated with oenological tannins showed higher total phenols and flavonoid phenols and lesser color degradation during the aging time considered. After 120 aging days, wines aged with oenological tannins showed more total and individual anthocyanins and significantly more red color that induced significantly color differences in relation to the untreated wine (especially for the wines treated with condensed tannins. From a sensorial point of view it was also possible to detect a clear differentiation between the wines.

  18. Growth response of Avena sativa in amino-acids-rich soils converted from phenol-contaminated soils by Corynebacterium glutamicum.

    Science.gov (United States)

    Lee, Soo Youn; Kim, Bit-Na; Choi, Yong Woo; Yoo, Kye Sang; Kim, Yang-Hoon; Min, Jiho

    2012-04-01

    The biodegradation of phenol in laboratory-contaminated soil was investigated using the Gram-positive soil bacterium Corynebacterium glutamicum. This study showed that the phenol degradation caused by C. glutamicum was greatly enhanced by the addition of 1% yeast extract. From the toxicity test using Daphnia magna, the soil did not exhibit any hazardous effects after the phenol was removed using C. glutamicum. Additionally, the treatment of the phenolcontaminated soils with C. glutamicum increased various soil amino acid compositions, such as glycine, threonine, isoleucine, alanine, valine, leucine, tyrosine, and phenylalanine. This phenomenon induced an increase in the seed germination rate and the root elongation of Avena sativa (oat). This probably reflects that increased soil amino acid composition due to C. glutamicum treatment strengthens the plant roots. Therefore, the phenol-contaminated soil was effectively converted through increased soil amino acid composition, and additionally, the phenol in the soil environment was biodegraded by C. glutamicum.

  19. Study on The Application of Composed TiO2-diatomite in The Removal of Phenol in Water

    Science.gov (United States)

    Liu, S.; Li, J.

    2017-10-01

    As an environmentally friendly pollution control technology, TiO2 photocatalytic technology has a broad prospect in the field of environmental protection. In this paper, composed nano-TiO2-diatomite were prepared by depositing TiO2 nanoparticles on the surface of diatomite microparticles. The nano-TiO2/diatomite composed photocatalyst is used to remove phenol in water in a specific designed reaction box under 4 different operation factors such as different reaction time, different pollutant concentration, different UV light powers and different amount of catalytic powder. The experimental results indicate that the phenol removal percentages are influenced by the reaction time most significantly, the second is the phenol concentration, the next one is the photocatalyst amount and the UV light powers’ effect is quite limited. Tthe degradation of phenol typically slows down at the reaction time about 30 or 60 minutes. Besides that, the phenol removal kinetic removal rates were also investigated.

  20. Anaerobic biogranulation in a hybrid reactor treating phenolic waste

    International Nuclear Information System (INIS)

    Ramakrishnan, Anushyaa; Gupta, S.K.

    2006-01-01

    Granulation was examined in four similar anaerobic hybrid reactors 15.5 L volume (with an effective volume of 13.5 L) during the treatment of synthetic coal wastewater at the mesophilic temperature of 27 ± 5 deg. C. The hybrid reactors are a combination of UASB unit at the lower part and an anaerobic filter at the upper end. Synthetic wastewater with an average chemical oxygen demand (COD) of 2240 mg/L, phenolics concentration of 752 mg/L and a mixture of volatile fatty acids was fed to three hybrid reactors. The fourth reactor, control system, was fed with a wastewater containing sodium acetate and mineral nutrients. Coal waste water contained phenol (490 mg/L); m-, o-, p-cresols (123.0, 58.6, 42 mg/L); 2,4-, 2,5-, 3,4- and 3,5-dimethyl phenols (6.3, 6.3, 4.4 and 21.3 mg/L) as major phenolic compounds. A mixture of anaerobic digester sludge and partially granulated sludge (3:1) were used as seed materials for the start up of the reactors. Granules were observed after 45 days of operation of the systems. The granules ranged from 0.4 to 1.2 mm in diameter with good settling characteristics with an SVI of 12 mL/g SS. After granulation, the hybrid reactor performed steadily with phenolics and COD removal efficiencies of 93% and 88%, respectively at volumetric loading rate of 2.24 g COD/L d and hydraulic retention time of 24 h. The removal efficiencies for phenol and m/p-cresols reached 92% and 93% (corresponding to 450.8 and 153 mg/L), while o-cresol was degraded to 88% (corresponding to 51.04 mg/L). Dimethyl phenols could be removed completely at all the organic loadings and did not contribute much to the residual organics. Biodegradation of o-cresol was obtained in the hybrid-UASB reactors

  1. Sorption of a phenols mixture in aqueous solution with activated carbon

    International Nuclear Information System (INIS)

    Mejia M, D.

    2004-01-01

    The constant population growth and the quick industrialization have caused severe damages to our natural aquifer resources for a great variety of organic and inorganic pollutants. Among these they are those phenol compounds that are highly toxic, resistant (to the degradation chemistry) and poorly biodegradable. The phenolic compounds is used in a great variety of industries, like it is the production of resins, nylon, plastifiers, anti-oxidants, oil additives, drugs, pesticides, colorants, explosives, disinfectants and others. The disseminated discharges or effluents coming from the industrial processes toward lakes and rivers are causing a growing adverse effect in the environment, as well as a risk for the health. Numerous studies exist on the phenols removal and phenols substituted for very varied techniques, among them they are the adsorption in activated carbon. This finishes it has been used successfully for the treatment of residual waters municipal and industrial and of drinking waters and it is considered as the best technique available to eliminate organic compounds not biodegradable and toxic present in aqueous solution (US EPA, 1991). However a little information exists on studies carried out in aqueous systems with more of a phenolic compound. The activated carbon is broadly used as adsorbent due to its superficial properties in the so much treatment of water as of aqueous wastes, adsorbent for the removal of organic pollutants. The main objective of this work is the adsorption of a aqueous mixture of phenol-4 chloro phenol of different concentrations in activated carbon of mineral origin of different meshes and to diminish with it their presence in water. The experiments were carried out for lots, in normal conditions of temperature and pressure. The experimental results show that the removal capacity depends so much of the superficial properties of the sorbent like of the physical properties and chemical of the sorbate. The isotherms were carried

  2. Bioavailability of dietary phenolic compounds: Review

    Directory of Open Access Journals (Sweden)

    Erick Gutiérrez-Grijalva Paul Gutiérrez-Grijalva

    2015-12-01

    Full Text Available Phenolic compounds are ubiquitous in plant-based foods. High dietary intake of fruits, vegetables and cereals is related to a decreased rate in chronic diseases. Phenolic compounds are thought to be responsible, at least in part, for those health effects. Nonetheless, phenolic compounds bioaccessibility and biotransformation is often not considered in these studies; thus, a precise mechanism of action of phenolic compounds is not known. In this review we aim to present a comprehensive knowledge of the metabolic processes through which phenolic compounds go after intake.

  3. Phenols and aromatic amines as thermal stabilizers in polyolefin processing

    Czech Academy of Sciences Publication Activity Database

    Pospíšil, Jan; Habicher, W. D.; Al-Malaika, S.; Zweifel, H.; Nešpůrek, Stanislav

    2001-01-01

    Roč. 176, - (2001), s. 55-63 ISSN 1022-1360. [International Conference on Polymer Modification, Degradation and Stabilization /1./. Palermo, 03.09.2000-07.09.2000] R&D Projects: GA AV ČR IAA1050901; GA MŠk ME 184; GA MŠk ME 372; GA AV ČR KSK4050111 Institutional research plan: CEZ:AV0Z4050913 Keywords : thermal stabilizers * phenols * aromatic amines Subject RIV: CD - Macromolecular Chemistry Impact factor: 0.634, year: 2001

  4. Biodegradation of high concentrations of phenol by baker’s yeast in anaerobic sequencing batch reactor

    Directory of Open Access Journals (Sweden)

    Ali Asghar Najafpoor

    2015-06-01

    Full Text Available Background: Phenol, as a pure substance, is used in many fields because of its disinfectant, germicidal, local anesthetic, and peptizing properties. Aqueous solutions of phenol are produced as waste in industries and discharged into the environment. Therefore, elevated concentrations of phenol may be found in air or water because of industrial discharge or the use of phenolic products. Method: The strains of Saccharomyces cerevisiae used in this project were natural strains previously purchased from Razavy company. They were grown at 30°C on Petri plates containing yeast extract glucose (YGC and then purified by being spread onto new plates, and isolated colonies were obtained. These colonies provided the basis of selection. Prepared strains were applied in anaerobic sequencing batch reactors (ASBRs as first seed. The experiment conditions were optimized using response surface methodology (RSM. After the determined runs were performed using Design-Expert software, data were analyzed using mentioned software as well. Results: This study evaluated the capability of baker’s yeast to remove phenol in high concentrations. The tested strains showed excellent tolerance to phenol toxicity at concentrations up to 6100 mg/L. Study of the batch degradation process showed that the phenol removal rate could exceed 99.9% in 24 hours at a concentration of 1000 mg/L. The results showed catechol is the first intermediate product of phenol degradation. In survey results of the Design–Expert software, R2 and Adeq precision were 0.97 and 25.65, respectively. Conclusion: The results demonstrated that ASBR performs robustly under variable influent concentrations of inhibitory compounds. The high removal performance despite the high phenol concentration may be a result of reactor operating strategies. Based on the progressive increase of inlet phenol concentration, allowing for an enhanced biomass acclimation in a short time, results at the microbiological levels

  5. Novel regulator MphX represses activation of phenol hydroxylase genes caused by a XylR/DmpR-type regulator MphR in Acinetobacter calcoaceticus.

    Science.gov (United States)

    Yu, Haiying; Peng, Zixin; Zhan, Yuhua; Wang, Jin; Yan, Yongliang; Chen, Ming; Lu, Wei; Ping, Shuzhen; Zhang, Wei; Zhao, Zhonglin; Li, Shuying; Takeo, Masahiro; Lin, Min

    2011-03-24

    Acinetobacter calcoaceticus PHEA-2 utilizes phenol as its sole carbon and energy source and has a multi-component phenol hydroxylase-encoding gene operon (mphKLMNOP) for phenol degradation. Two additional genes, mphR and mphX, were found upstream and downstream of mphKLMNOP, respectively. The mphR gene encodes a XylR/DmpR-type regulator-like protein and is transcribed in the opposite direction to mphKLMNOP. The mphX gene is transcribed in the same direction as mphKLMNOP and encodes a protein with 293 amino acid residues showing weak identity with some unknown proteins encoded in the meta-cleavage pathway gene clusters for aromatic compound degradation. Disruption of mphR by homologous recombination resulted in the loss of phenol degradation while disruption of mphX caused significantly faster phenol degradation than in the wild type strain. Transcriptional assays for mphK, mphR, and mphX revealed that mphR activated mphKLMNOP transcription in the presence of phenol, but mphX partially repressed this activation. Gel mobility-shift assay demonstrated a direct interaction of MphR with the mphK promoter region. These results indicate the involvement of a novel repressor protein MphX in transcriptional regulation of phenol hydroxylase genes caused by a XylR/DmpR-type regulator MphR.

  6. Novel regulator MphX represses activation of phenol hydroxylase genes caused by a XylR/DmpR-type regulator MphR in Acinetobacter calcoaceticus.

    Directory of Open Access Journals (Sweden)

    Haiying Yu

    2011-03-01

    Full Text Available Acinetobacter calcoaceticus PHEA-2 utilizes phenol as its sole carbon and energy source and has a multi-component phenol hydroxylase-encoding gene operon (mphKLMNOP for phenol degradation. Two additional genes, mphR and mphX, were found upstream and downstream of mphKLMNOP, respectively. The mphR gene encodes a XylR/DmpR-type regulator-like protein and is transcribed in the opposite direction to mphKLMNOP. The mphX gene is transcribed in the same direction as mphKLMNOP and encodes a protein with 293 amino acid residues showing weak identity with some unknown proteins encoded in the meta-cleavage pathway gene clusters for aromatic compound degradation. Disruption of mphR by homologous recombination resulted in the loss of phenol degradation while disruption of mphX caused significantly faster phenol degradation than in the wild type strain. Transcriptional assays for mphK, mphR, and mphX revealed that mphR activated mphKLMNOP transcription in the presence of phenol, but mphX partially repressed this activation. Gel mobility-shift assay demonstrated a direct interaction of MphR with the mphK promoter region. These results indicate the involvement of a novel repressor protein MphX in transcriptional regulation of phenol hydroxylase genes caused by a XylR/DmpR-type regulator MphR.

  7. High Phenolics Rutgers Scarlet Lettuce Improves Glucose Metabolism in High Fat Diet-Induced Obese Mice

    Science.gov (United States)

    Cheng, Diana M.; Roopchand, Diana E.; Poulev, Alexander; Kuhn, Peter; Armas, Isabel; Johnson, William D.; Oren, Andrew; Ribnicky, David; Zelzion, Ehud; Bhattacharya, Debashish; Raskin, Ilya

    2016-01-01

    Scope The ability of high phenolic Rutgers Scarlet Lettuce (RSL) to attenuate metabolic syndrome and gut dysbiosis was studied in very high fat diet (VHFD)-fed mice. Phenolic absorption was assessed in vivo and in a gastrointestinal tract model. Methods and results Mice were fed VHFD, VHFD supplemented with RSL (RSL-VHFD) or store-purchased green lettuce (GL-VHFD), or low-fat diet (LFD) for 13 weeks. Compared to VHFD or GL-VHFD-fed groups, RSL-VHFD group showed significantly improved oral glucose tolerance (p<0.05). Comparison of VHFD, RSL-VHFD, and GL-VHFD groups revealed no significant differences with respect to insulin tolerance, hepatic lipids, body weight gain, fat mass, plasma glucose, triglycerides, free fatty acid, and lipopolysaccharide levels, as well as relative abundances of major bacterial phyla from 16S rDNA amplicon data sequences (from fecal and cecal samples). However, RSL and GL-supplementation increased abundance of several taxa involved in plant polysaccharide degradation/fermentation. RSL phenolics chlorogenic acid, quercetin-3-glucoside, and quercetin-malonyl-glucoside were bioaccessible in the TIM-1 digestion model, but had relatively low recovery. Conclusions RSL phenolics contributed to attenuation of postprandial hyperglycemia. Changes in gut microbiota were likely due to microbiota accessible carbohydrates in RSL and GL rather than RSL phenolics, which may be metabolized, absorbed, or degraded before reaching the colon. PMID:27529448

  8. Cathode degradation

    Energy Technology Data Exchange (ETDEWEB)

    Shores, D.A.; Selman, J.R.; Ong, E.T.

    1989-12-01

    This report describes the results of a three-year study of cathode degradation in molten carbonate fuel cells involving both experimental and theoretical work. A keystone of the study is the development of a mathematical model, which describes cathode degradation in terms of the fundamental processes of a fluxing mechanism, i.e., dissolution, transport and precipitation. New fundamental data have been obtained on the solubility of NiO, especially on the effect of water vapor, and on the kinetics of NiO dissolution in (Li{sub 0.62}K{sub 0.38}){sub 2}CO{sub 3}, and these data have been incorporated in the model. Laboratory cell testing in 3 cm{sup 2} cells has been carried out to obtain experimental data on degradation rates for direct comparison with the calculated results from the model. These comparisons have helped to verify several aspects of the model. For example, the model predicts with fair accuracy the location of the Ni deposit in the tile and the deposition rate. It is also fair to point out that the model is a relatively simple representation of complex processes, and it does not answer all questions about cathode degradation. Further work is needed. Because of its fundamental basis, the model can readily be upgraded and extended when further experimental data become available. The solubility studies, modeling efforts and cell testing have interacted iteratively to optimize progress. 94 figs., 24 tabs.

  9. Prompting Strategies for Introducing Opera.

    Science.gov (United States)

    Beck, Charles R.

    2002-01-01

    Describes how to introduce opera to students through the use of prompting strategies. Explains that these strategies encourage active participation by students and help to improve listening skills. Focuses on prompting strategies, such as matching characters to songs, identifying, and sequencing songs. (CMK)

  10. Introducing Positive Psychology to SLA

    Science.gov (United States)

    MacIntyre, Peter D.; Mercer, Sarah

    2014-01-01

    Positive psychology is a rapidly expanding subfield in psychology that has important implications for the field of second language acquisition (SLA). This paper introduces positive psychology to the study of language by describing its key tenets. The potential contributions of positive psychology are contextualized with reference to prior work,…

  11. Introducing Happiness: A Practical Guide

    OpenAIRE

    Buckingham, Will

    2012-01-01

    A brief and breezy guide to the various philosophies of happiness—from Zhuangzi to the world of Positive Psychology and from Epicurus to the Buddha—packed with entertaining and fun exercises. Introducing Happiness is also a very intense shade of yellow.

  12. Game Design to Introduce Pets

    Directory of Open Access Journals (Sweden)

    Wahyu Febriyanto

    2017-02-01

    Full Text Available Introduction of animals from an early age can make children to love animals, especially pets. Children are the easiest group to receive stimulation, such as for example the stimulation of introducing children to the pet. Various media are used by parents to introduce pet. For examplle, by the media of books, multimedia, etc. One of the interesting media to introduce pet is with game. Of these problems then need to know how to make concept and design game to introduced pets for children age 3-6 years. In this paper, author formulate how to make pet game design include game genre, user interface design, image model selection, game characters, and game engine. The expected design of this game can be formulation of learning through proper game as a learning tool children. Game design derived from this writing by using model 2-dimensional images are funny and interesting coloring. And combines several game genres into one, or use the mini games that children do not get bored quickly. Design of GUI (Graphical User Interface is made as simple as possible so that children easily understand in playing this game, but also must use an interesting image

  13. Introduce XBRL to Business Students

    Science.gov (United States)

    Corkern, Sheree M.; Morgan, Mark I.

    2012-01-01

    This paper informs business instructors and educators about XBRL (Extensible Business Reporting Language) so that they can introduce it to their students and expand their students' understanding of how it relates to the accounting profession. Even though the financial community has entered a new age with this standardized reporting language, many…

  14. An Exercise to Introduce Power

    Science.gov (United States)

    Seier, Edith; Liu, Yali

    2013-01-01

    In introductory statistics courses, the concept of power is usually presented in the context of testing hypotheses about the population mean. We instead propose an exercise that uses a binomial probability table to introduce the idea of power in the context of testing a population proportion. (Contains 2 tables, and 2 figures.)

  15. Electrochemical Incineration of Phenolic Compounds from the Hydrocarbon Industry Using Boron-Doped Diamond Electrodes

    Directory of Open Access Journals (Sweden)

    Alejandro Medel

    2012-01-01

    Full Text Available Electrochemical incineration using boron-doped diamond electrodes was applied to samples obtained from a refinery and compared to the photo-electro-Fenton process in order to selectively eliminate the phenol and phenolic compounds from a complex matrix. Due to the complex chemical composition of the sample, a pretreatment to the sample in order to isolate the phenolic compounds was applied. The effects of the pretreatment and of pH on the degradation of the phenolic compounds were evaluated. The results indicate that the use of a boron-doped diamond electrode in an electrochemical incineration process mineralizes 99.5% of the phenolic sample content. Working in acidic medium (pH = 1, and applying 2 A at 298 K under constant stirring for 2 hours, also results in the incineration of the reaction intermediates reflected by 97% removal of TOC. In contrast, the photo-electro-Fenton process results in 99.9% oxidation of phenolic compounds with only a 25.69% removal of TOC.

  16. Benzene electro-oxidation in a PEMFC for phenol and electricity cogeneration

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Rui; Ji, Baofeng; Yang, Weishen; Xin, Qin [State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, CAS, P.O. Box 110, 116023 Dalian (China); Song, Shuqin; Douvartzides, Savvas; Tsiakaras, Panagiotis [Department of Mechanical Engineering, School of Engineering, University of Thessalia, Pedion Areos, 383 34 Volos (Greece); Sun, Gongquan [Direct Alcohol Fuel Cell Lab, Dalian Institute of Chemical Physics, CAS, P.O. Box 110, 116023 Dalian (China)

    2005-11-09

    In the present investigation, the electrochemically-assisted oxidation of benzene in a H{sub 2}-O{sub 2} proton exchange membrane fuel cell (PEMFC), for electricity and phenol cogeneration is studied. Experiments were carried out in a PEMFC electrochemical reactor using Pd black as cathode electrocatalyst at 60 and 80{sup o}C, respectively and 1atm back pressure. Indeed, it was found that the only product detected under the examined experimental conditions was phenol. The online GC product analysis revealed that it is impossible to produce phenol when the fuel cell circuit is open (I=0) under all the examined experimental conditions. When the fuel cell circuit was closed, however, the phenol yield was found to follow a volcano-type dependence on the current of the external circuit. It was found that the maximum phenol yield was 0.35% at 100mA/cm{sup 2} at 80{sup o}C. At the same time, the PEMFC performance was also investigated during the phenol generation process. Furthermore, experiments with the rotating ring disc electrode (RRDE) technique showed that the intermediate oxidation product, i.e. H{sub 2}O{sub 2} existed during the oxygen electro-reduction process. The cyclic voltammograms showed that benzene was strongly adsorbed on the Pd surface, leading to a degradation of the PEMFC performance.

  17. Simultaneous Removal of Phenol and Dissolved Solids from Wastewater Using Multichambered Microbial Desalination Cell.

    Science.gov (United States)

    Pradhan, Harapriya; Jain, Sumat Chand; Ghangrekar, Makarand M

    2015-12-01

    Microbial desalination cell (MDC) has great potential toward direct electricity generation from wastewater and concurrent desalination through potential difference developed due to microbial activity. Degradation of phenol by isolate Pseudomonas aeruginosa in anodic chamber and simultaneous desalination of water in middle desalination chamber of multichamber MDC is demonstrated in this study. Performance of the MDCs with different anodic inoculum conditions, namely pure culture of P. aeruginosa (MDC-1), 50 % v/v mixture of P. aeruginosa and anaerobic mixed consortia (MDC-2) and anaerobic mixed consortia (MDC-3), was evaluated to compare the phenol degradation in anodic chamber, bioelectricity generation, and simultaneous total dissolved solids (TDS) removal from saline water in desalination chamber. Synergistic effect between P. aeruginosa and mixed anaerobic consortia as inoculum was evident in MDC-2 demonstrating phenol degradation of 90 %, TDS removal of 75 % in 72 h of reaction time along with higher power generation of 27.5 mW/m(2) as compared to MDC-1 (95 %, 64 %, 12.8 mW/m(2), respectively) and MDC-3 (58 %, 52 %, 4.8 mW/m(2), respectively). The results illustrate that the multichamber MDC-2 is effective for simultaneous removal of phenol and dissolved solids contained in industrial wastewaters.

  18. Impact of phenolic substrate and growth temperature on the arthrobacter chlorophenolicus proteome

    Energy Technology Data Exchange (ETDEWEB)

    Unell, Maria; Abraham, Paul E.; Shah, Manesh; Zhang, Bing; Ruckert, Christian; VerBerkmoes, Nathan C.; Jansson, Janet K.

    2009-02-15

    We compared the Arthrobacter chlorophenolicus proteome during growth on 4-chlorophenol, 4-nitrophenol or phenol at 5 C and 28 C; both for the wild type and a mutant strain with mass spectrometry based proteomics. A label free workflow employing spectral counting identified 3749 proteins across all growth conditions, representing over 70% of the predicted genome and 739 of these proteins form the core proteome. Statistically significant differences were found in the proteomes of cells grown under different conditions including differentiation of hundreds of unknown proteins. The 4-chlorophenol-degradation pathway was confirmed, but not that for phenol.

  19. Radiation degradation of aromatic pollutants exit in wastewater and ph dependence

    CERN Document Server

    Takriti, S

    2002-01-01

    The effect of gamma radiation on the degradation of phenol (hydroxybenzene), resorcinol (1,3 dihydroxybenzen) and hydroquinone (1,4 dihydroxybenzen) exit in waste water was investigated. The concentrations of these pollutants as well as the irradiated solution ph were studied. The results showed that the phenol is very resistance against the radiation doses comparing the other phenol compounds. Phenol was also a product of radiolysis of resorcinol and hydroquinone. On the other hand, the acid phase of the irradiation sample increased the degradation rate of pollutants. Spectrophotometer (UV-VIS) and chromatography (HPLC) were used to monitor the analysis of the radiation product solution. The results illustrated the existing of many substances such as organic alcohol, aldehyde, ketone and acidic functional groups as a final radiation products. The degradation of benzene, monochlorobenzene (CB) and 1,2 dichlorobenzene (1,2 DCB) exit in waste water by gamma irradiation was investigated. The effect of the irradi...

  20. Laccase catalyzed synthesis of iodinated phenolic compounds with antifungal activity.

    Directory of Open Access Journals (Sweden)

    Julian Ihssen

    Full Text Available Iodine is a well known antimicrobial compound. Laccase, an oxidoreductase which couples the one electron oxidation of diverse phenolic and non-phenolic substrates to the reduction of oxygen to water, is capable of oxidizing unreactive iodide to reactive iodine. We have shown previously that laccase-iodide treatment of spruce wood results in a wash-out resistant antimicrobial surface. In this study, we investigated whether phenolic compounds such as vanillin, which resembles sub-structures of softwood lignin, can be directly iodinated by reacting with laccase and iodide, resulting in compounds with antifungal activity. HPLC-MS analysis showed that vanillin was converted to iodovanillin by laccase catalysis at an excess of potassium iodide. No conversion of vanillin occurred in the absence of enzyme. The addition of redox mediators in catalytic concentrations increased the rate of iodide oxidation ten-fold and the yield of iodovanillin by 50%. Iodinated phenolic products were also detected when o-vanillin, ethyl vanillin, acetovanillone and methyl vanillate were incubated with laccase and iodide. At an increased educt concentration of 0.1 M an almost one to one molar ratio of iodide to vanillin could be used without compromising conversion rate, and the insoluble iodovanillin product could be recovered by simple centrifugation. The novel enzymatic synthesis procedure fulfills key criteria of green chemistry. Biocatalytically produced iodovanillin and iodo-ethyl vanillin had significant growth inhibitory effects on several wood degrading fungal species. For Trametes versicolor, a species causing white rot of wood, almost complete growth inhibition and a partial biocidal effect was observed on agar plates. Enzymatic tests indicated that the iodinated compounds acted as enzyme responsive, antimicrobial materials.

  1. Oxidative phenols in forage crops containing polyphenol oxidase enzymes.

    Science.gov (United States)

    Parveen, Ifat; Threadgill, Michael D; Moorby, Jon M; Winters, Ana

    2010-02-10

    Polyphenol oxidases (PPOs) are copper-containing enzymes that catalyze oxidation of endogenous monophenols to ortho-dihydroxyaryl compounds and of ortho-dihydroxyaryl compounds to ortho-quinones. Subsequent nucleophilic addition reactions of phenols, amino acids, and proteins with the electrophilic ortho-quinones form brown-, black-, or red-colored secondary products associated with the undesired discolouration of fruit and vegetables. Several important forage plants also exhibit significant PPO activity, and a link with improved efficiency of ruminant production has been established. In ruminant animals, extensive degradation of forage proteins, following consumption, can result in high rates of excretion of nitrogen, which contributes to point-source and diffuse pollution. Reaction of quinones with forage proteins leads to the formation of protein-phenol complexes that are resistant to proteolytic activity during ensilage and during rumen fermentation. Thus, PPO in red clover (Trifolium pratense) has been shown to improve protein utilization by ruminants. While PPO activity has been demonstrated in a number of forage crops, little work has been carried out to identify substrates of PPO, knowledge of which would be beneficial for characterizing this trait in these forages. In general, a wide range of 1,2-dihydroxyarenes can serve as PPO substrates because these are readily oxidized because of the ortho positioning of the hydroxy groups. Naturally occurring phenols isolated from forage crops with PPO activity are reviewed. A large number of phenols, which may be directly or indirectly oxidized as a consequence of PPO activity, have been identified in several forage grass, legume, cereal, and brassica species; these include hydroxybenzoic acids, hydroxycinnamates, and flavonoids. In conclusion, a number of compounds are known or postulated to enable PPO activity in important PPO-expressing forage crops. Targeting the matching of these compounds with PPO activity

  2. Chemistry and health of olive oil phenolics.

    Science.gov (United States)

    Cicerale, Sara; Conlan, Xavier A; Sinclair, Andrew J; Keast, Russell S J

    2009-03-01

    The Mediterranean diet is associated with a lower incidence of atherosclerosis, cardiovascular disease, and certain types of cancer. The apparent health benefits have been partially attributed to the dietary consumption of virgin olive oil by Mediterranean populations. Most recent interest has focused on the biologically active phenolic compounds naturally present in virgin olive oils. Studies (human, animal, in vivo and in vitro) have shown that olive oil phenolics have positive effects on certain physiological parameters, such as plasma lipoproteins, oxidative damage, inflammatory markers, platelet and cellular function, and antimicrobial activity. Presumably, regular dietary consumption of virgin olive oil containing phenolic compounds manifests in health benefits associated with a Mediterranean diet. This paper summarizes current knowledge on the physiological effects of olive oil phenolics. Moreover, a number of factors have the ability to affect phenolic concentrations in virgin olive oil, so it is of great importance to understand these factors in order to preserve the essential health promoting benefits of olive oil phenolic compounds.

  3. Immobilization of Tyrosinase on (3-Aminopropyltriethoxysilane-Functionalized Carbon Felt-Based Flow-Through Detectors for Electrochemical Detection of Phenolic Compounds

    Directory of Open Access Journals (Sweden)

    Zheng Zhou

    2017-07-01

    Full Text Available Tyrosinase (TYR was covalently immobilized onto amino-functionalized carbon felt (CF surface via glutaraldehyde (GA. Prior to the TYR-immobilization, primary amino group was introduced to the CF surface by treatment with 3-aminopropyltriethoxysilane (APTES. The resulting TYR-immobilized CF was used as a working electrode unit of an electrochemical flow-through detector for mono- and di-phenolic compounds (i.e., catechol, p-cresol, phenol and p-chlorophenol. Additionally, flow injection peaks based on electroreduction of the enzymatically produced o-quinone species were detected at −0.05 V vs. Ag/AgCl. The resulting TYR/GA/APTES/CF biosensor responded well to all compounds tested with limits of detection range from 7.5 to 35 nmol−1 (based on three times S/N ratio. Moreover, such modified electrode exhibits good stability and reproducibility for catechol. No serious degradation of the peak current was found over 30 consecutive injections.

  4. Reaction pathway of the degradation of the p-hydroxybenzoic acid by sulfate radical generated by ionizing radiations

    International Nuclear Information System (INIS)

    Criquet, Justine; Leitner, Nathalie Karpel Vel

    2015-01-01

    The degradation of p-hydroxybenzoic acid (HBA) in aqueous solutions by ionizing radiation was studied. The phenolic pollutant was easily removed by the electron beam irradiation, as more than 80% of the initial 100 µM introduced was degraded for a dose of 600 Gy. It was shown that the addition of persulfate, producing the sulfate radical as additional reactive species, induced a change in the reaction pathway. LC–MS analyses were performed in order to identify the different by-products formed. In the absence of persulfate, the main by-product formed was 3,4-dihydroxybenzoic acid, while in presence of persulfate, 1,4-benzoquinone was detected and the hydroxylated by-products were not present. A reaction pathway of HBA degradation by hydroxyl and sulfate radicals was proposed from the identification of the chemical structure of the different by-products detected. The influences of pH and dissolved oxygen were also studied. A high decline of HBA degradation was observed at pH 11 compared to pH 4.5, this decrease was minimized in the presence of persulfate. The dissolved oxygen concentration was found to be a limiting parameter of HBA degradation, however an excess of dissolved oxygen in solution did not improve the degradation to a large extent. - Highlights: • p-Hydroxybenzoic acid (HBA) is easily removed by e-beam irradiation. • The sulfate radicals formed from persulfate induce loss of the benzoic acid skeleton. • The dissolved oxygen concentration is a limiting parameter of the HBA degradation. • The effect of pH is minimized in presence of persulfate

  5. Flexible Phenolic Impregnated Felt, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — During this program Fiber Materials, Inc. (FMI) will develop innovative yet practical methods for preparing Phenolic Impregnated Felt (PIF) materials for thermal...

  6. Introducing the Global Register of Introduced and Invasive Species

    Science.gov (United States)

    Pagad, Shyama; Genovesi, Piero; Carnevali, Lucilla; Schigel, Dmitry; McGeoch, Melodie A.

    2018-01-01

    Harmonised, representative data on the state of biological invasions remain inadequate at country and global scales, particularly for taxa that affect biodiversity and ecosystems. Information is not readily available in a form suitable for policy and reporting. The Global Register of Introduced and Invasive Species (GRIIS) provides the first country-wise checklists of introduced (naturalised) and invasive species. GRIIS was conceived to provide a sustainable platform for information delivery to support national governments. We outline the rationale and methods underpinning GRIIS, to facilitate transparent, repeatable analysis and reporting. Twenty country checklists are presented as exemplars; GRIIS Checklists for close to all countries globally will be submitted through the same process shortly. Over 11000 species records are currently in the 20 country exemplars alone, with environmental impact evidence for just over 20% of these. GRIIS provides significant support for countries to identify and prioritise invasive alien species, and establishes national and global baselines. In future this will enable a global system for sustainable monitoring of trends in biological invasions that affect the environment. PMID:29360103

  7. Phenolic Constituents from Alchornea castaneifolia

    Directory of Open Access Journals (Sweden)

    Michał Gleńsk

    2016-01-01

    Full Text Available Alchornea castaneifolia is a tree growing commonly in several South American countries. It is best known under its Peruvian name Iporuru. The leaves are being used as a folk remedy against numerous symptoms associated with pain and inflammation. It has a reputation for being a tonic and booster of male libido. In this study, using a combination of chromatographic techniques, we isolated phenolic constituents present in leaves, and elucidated their structures using MS and NMR techniques. The isolated and characterized compounds were myricetin glucoside, myricetin galactoside, proanthocyanidin A1 and A2, epicatechin, gallic acid, shikimic acid, putranjivain A, elaeocarpusin and never before isolated methyl ester of repandusinic acid A.

  8. Introducing ZBrush 3rd Edition

    CERN Document Server

    Keller, Eric

    2012-01-01

    Learn ZBrush inside and out with this updated new edition Get totally comfortable sculpting in a digital environment with the latest edition of this bestselling beginner's guide to ZBrush. Fully updated for the newest version of the software, ZBrush 4R3, this book dispels any fears you might have about the difficulty of using ZBrush and soon has you creating realistic, cartoon, and organic models with flair. Learn all the essentials, as you complete fun tutorials on painting, meshes, organic scripting, hard surface sculpting, lighting, rendering, and more. Introduces you to ZBrush, the sculpt

  9. Introducing the Medical Ethics Bowl.

    Science.gov (United States)

    Merrick, Allison; Green, Rochelle; Cunningham, Thomas V; Eisenberg, Leah R; Hester, D Micah

    2016-01-01

    Although ethics is an essential component of undergraduate medical education, research suggests that current medical ethics curricula face considerable challenges in improving students' ethical reasoning. This article discusses these challenges and introduces a promising new mode of graduate and professional ethics instruction for overcoming them. We begin by describing common ethics curricula, focusing in particular on established problems with current approaches. Next, we describe a novel method of ethics education and assessment for medical students that we have devised: the Medical Ethics Bowl (MEB). Finally, we suggest the pedagogical advantages of the MEB when compared to other ethics curricula.

  10. Introducing Character Animation with Blender

    CERN Document Server

    Mullen, Tony

    2011-01-01

    Introducing Character Animation with Blender, 2nd Edition is written in a friendly but professional tone, with clear descriptions and numerous illustrative screenshots. Throughout the book, tutorials focus on how to accomplish actual animation goals, while illustrating the necessary technical methods along the way. These are reinforced by clear descriptions of how each specific aspect of Blender works and fits together with the rest of the package. By following all the tutorials, the reader will gain all the skills necessary to build and animate a well-modeled, fully-rigged character of their

  11. Davies, Florence (1995. Introducing Reading. Davies, Florence (1995. Introducing Reading.

    Directory of Open Access Journals (Sweden)

    Sonia Maria Gomes Ferreira

    2008-04-01

    Full Text Available Arising at a time of unprecedented growth of interest in fostering critical thinking, Introducing Reading offers a clear introduction and thorough account of contemporary developments in the field of reading. While overtly focusing on the special demands of social and human aspects of the reading practice, the issues raised have crucial resonance in the sphere of critical reading. Explicitly addressed to teachers of mother tongue and foreign language contexts, the book claims to elaborate on aspects of reading which have received meager attention to date: individual readers engaged in different real-world reading tasks, the social contexts where such readers engage and interact with texts, and the nature and variety of texts, here regarded as “participants” in the interaction between reader and writer. To this extent, the book successfully reaches the ambitious aim of “socializing and humanizing reading and the teaching of reading” (p. xi. Arising at a time of unprecedented growth of interest in fostering critical thinking, Introducing Reading offers a clear introduction and thorough account of contemporary developments in the field of reading. While overtly focusing on the special demands of social and human aspects of the reading practice, the issues raised have crucial resonance in the sphere of critical reading. Explicitly addressed to teachers of mother tongue and foreign language contexts, the book claims to elaborate on aspects of reading which have received meager attention to date: individual readers engaged in different real-world reading tasks, the social contexts where such readers engage and interact with texts, and the nature and variety of texts, here regarded as “participants” in the interaction between reader and writer. To this extent, the book successfully reaches the ambitious aim of “socializing and humanizing reading and the teaching of reading” (p. xi.

  12. Comparison between thermal and ozone regenerations of spent activated carbon exhausted with phenol.

    Science.gov (United States)

    Alvarez, P M; Beltrán, F J; Gómez-Serrano, V; Jaramillo, J; Rodríguez, E M

    2004-04-01

    Thermal and ozone regenerations of granular activated carbons (GAC) used in the removal of phenol from aqueous solution have been studied. The phenol isotherms for virgin GAC could be well represented by the Langmuir equation. Direct ozonation of GAC introduced large amounts of acidic surface oxygen groups, which caused a decrease in the phenol uptake. Thermogravimetric methods were used to investigate the mechanism of phenol adsorption onto virgin and ozonated carbons. Thermal regeneration was carried out at 1123K using nitrogen (pyrolysis alone) or nitrogen and carbon dioxide (pyrolysis plus oxidation). Results showed that spent carbons do not recover their adsorption characteristics when heated under inert conditions whereas carbon dioxide regeneration was effective at about 15% wt burn-off. Regeneration of GAC was also carried out with ozone as oxidizing gas at room temperature. Ozone dose and the nature of GAC have much influence on the regeneration performance. For an individual GAC there exits an optimum ozone dose for which phenol is eliminated together with most of its oxidation by-products without incurring in carbon surface chemical alterations. However, if excessive ozone is applied some acidic surface groups are formed on the GAC, thereby decreasing the adsorption capacity for phenol. Results showed that spent carbons can recover most of their adsorption characteristics and specific surface areas when regenerated through a number of adsorption-ozone regeneration cycles.

  13. Degraded Crater

    Science.gov (United States)

    2004-01-01

    21 October 2004 Near the center of this Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image lies the degraded remnants of an old meteor impact crater. The terrain in which it occurs is a heavily eroded, north middle-latitude surface. The image is located in the fretted terrains north of Arabia Terra near 41.3oN, 305.8oW. The image covers an area about 3 km (1.9 mi) wide and sunlight illuminates the scene from the lower left.

  14. Phenolics, Antiradical Assay and Cytotoxicity of Processed Mango ...

    African Journals Online (AJOL)

    Phenolics, Antiradical Assay and Cytotoxicity of Processed Mango ( Mangifera indica ) and Bush Mango ( Irvingia gabonensis ) Kernels. ... Nigerian Food Journal ... Phenolic constituents (total phenols, flavonoids, tannins, and anthocyanins), comparative antiradical potency and cytotoxicity of processed mango (Mangifera ...

  15. Biodegradation of phenol by a newly isolated marine bacterial strain ...

    African Journals Online (AJOL)

    ajl yemi

    2011-12-26

    peptone agar plates with. 1500 mg/L phenol. ... biodegradation of the strain was up to 92.0% under the optimum conditions even when the phenol ... Growth of marine bacterial isolates in various concentration of phenol. Isolate.

  16. Food proteins as potential carriers for phenolics

    NARCIS (Netherlands)

    Bohin, M.C.

    2013-01-01

    The development of phenolic-rich functional foods is often limited by the off-tastes of phenolics that might be counteracted by sequestering these compounds using a carrier, thereby preventing them to interact with bitter taste receptors and salivary proteins. A range of common animal food proteins

  17. Biodegradation of phenol by Pseudomonas pictorum on ...

    African Journals Online (AJOL)

    Biodegradation of phenol using Pseudomonas pictorum (ATCC 23328) a potential biodegradant of phenol was investigated under different operating conditions. Chitin was chosen as a support material and then partially characterized physically and chemically. The pH of the solution was varied over a range of 7 – 9.

  18. Biodegradation of phenol with immobilized Pseuodomonas putida ...

    African Journals Online (AJOL)

    Biodegradation of phenol with immobilized Pseuodomonas putida activated carbon packed bio-filter tower. ... Comparative study on adsorption and simultaneous adsorption and biodegradation (SAB) of phenol using Pseuodomonas putida (MTCC 1194) in a biofilter tower packed with fresh granular activated carbon (GAC) ...

  19. Phenol esterase activity of porcine skin

    Science.gov (United States)

    The alkyl esters of plant-derived phenols may serve as slow-release sources for cutaneous delivery of antioxidants. The ability of skin esterases to hydrolyze phenolic esters was examined. Esters of tyrosol and hydroxytyrosol were prepared from decanoic and lipoic acids. Ferulic acid was esterified ...

  20. Phytochemical composition, total phenolic content and ferric ...

    African Journals Online (AJOL)

    The increased interest in discovering drugs from natural source led to the investigation of the phytochemical composition, the total phenolic content (TPC) and ferric reducing antioxidant power (FRAP) of leaf, stem and root bark extracts of S. sarmentosus DC. The total phenolic content of the extracts were examined using ...

  1. Olive oil phenols are absorbed in humans

    NARCIS (Netherlands)

    Vissers, M.N.; Zock, P.L.; Roodenburg, A.J.C.; Leenen, R.; Katan, M.B.

    2002-01-01

    Animal and in vitro studies suggest that olive oil phenols are effective antioxidants. The most abundant phenols in olive oil are the nonpolar oleuropein- and ligstroside-aglycones and the polar hydroxytyrosol and tyrosol. The aim of this study was to gain more insight into the metabolism of those

  2. Activity and resistance of iron-containing amorphous, zeolitic and mesostructured materials for wet peroxide oxidation of phenol.

    Science.gov (United States)

    Calleja, G; Melero, J A; Martínez, F; Molina, R

    2005-05-01

    Iron-containing materials have been prepared following several strategies of synthesis and using different silica supports (amorphous, zeolitic and mesostructured materials). Activity and stability of these materials was evaluated on the wet peroxide oxidation of phenol under mild reaction conditions (100 degrees C, air pressure of 1MPa and stoichiometric amount of hydrogen peroxide for the complete mineralisation of phenol). Their catalytic performance was monitored in terms of phenol and total organic carbon (TOC) conversions, by-products distribution (aromatics compounds and carboxylic acids) and degree of metal leached into the aqueous solution. The nature and local environment of iron species is strongly dependent on the synthetic route, which dramatically influences their catalytic performance. Crystalline iron oxide species supported over mesostructured SBA-15 materials have demonstrated to be the most interesting catalysts for phenol degradation according to its high organic mineralisation, low sensitivity to leaching out and good oxidant efficiency.

  3. Introducing positive psychology to SLA

    Directory of Open Access Journals (Sweden)

    Sarah Mercer

    2014-01-01

    Full Text Available Positive psychology is a rapidly expanding subfield in psychology that has important implications for the field of second language acquisition (SLA. This paper introduces positive psychology to the study of language by describing its key tenets. The potential contributions of positive psychology are contextualized with reference to prior work, including the humanistic movement in language teaching, models of motivation, the concept of an affective filter, studies of the good language learner, and the concepts related to the self. There are reasons for both encouragement and caution as studies inspired by positive psychology are undertaken. Papers in this special issue of SSLLT cover a range of quantitative and qualitative methods with implications for theory, research, and teaching practice. The special issue serves as a springboard for future research in SLA under the umbrella of positive psychology.

  4. Introducing Newton and classical physics

    CERN Document Server

    Rankin, William

    2002-01-01

    The rainbow, the moon, a spinning top, a comet, the ebb and flood of the oceans ...a falling apple. There is only one universe and it fell to Isaac Newton to discover its secrets. Newton was arguably the greatest scientific genius of all time, and yet he remains a mysterious figure. Written and illustrated by William Rankin, "Introducting Newton and Classical Physics" explains the extraordinary ideas of a man who sifted through the accumulated knowledge of centuries, tossed out mistaken beliefs, and single-handedly made enormous advances in mathematics, mechanics and optics. By the age of 25, entirely self-taught, he had sketched out a system of the world. Einstein's theories are unthinkable without Newton's founding system. He was also a secret heretic, a mystic and an alchemist, the man of whom Edmund Halley said "Nearer to the gods may no man approach!". This is an ideal companion volume to "Introducing Einstein".

  5. Determination of Phenolic Compounds in Wines

    Directory of Open Access Journals (Sweden)

    Charalampos Proestos

    2012-04-01

    Full Text Available Normal 0 false false false MicrosoftInternetExplorer4 Wine contains natural antioxidants such as phenolic compounds also known as bioactive compounds. Samples of commercially available Greek wines were analyzed in order to determine this phenolic content. For the analysis, Reversed Phase-High Performance Liquid Chromatography (RP-HPLC coupled with a multiwavelength Ultraviolet/visible (UV/vis detector was used. The most abundant phenolic substances detected were (+-catechin (13.5-72.4 mg L-1 , gallic acid (0.40-99.47 mg L-1 and caffeic acid (0.87-33.48 mg L-1. The principal component analysis (PCA technique was used to study differentiation among wines according to their production area. Red wines contained more phenolic substances than white ones. Differences of the phenolic composition in wines of the same cultivar were investigated too.

  6. Degradation of caffeic acid in subcritical water and online HPLC-DPPH assay of degradation products.

    Science.gov (United States)

    Khuwijitjaru, Pramote; Suaylam, Boonyanuch; Adachi, Shuji

    2014-02-26

    Caffeic acid was subjected to degradation under subcritical water conditions within 160-240 °C and at a constant pressure of 5 MPa in a continuous tubular reactor. Caffeic acid degraded quickly at these temperatures; the main products identified by liquid chromatography-diode array detection/mass spectrometry were hydroxytyrosol, protocatechuic aldehyde, and 4-vinylcatechol. The reaction rates for the degradation of caffeic acid and the formation of products were evaluated. Online high-performance liquid chromatography/2,2-diphenyl-1-picryhydrazyl assay was used to determine the antioxidant activity of each product in the solution. It was found that the overall antioxidant activity of the treated solution did not change during the degradation process. This study showed a potential of formation of antioxidants from natural phenolic compounds under these subcritical water conditions, and this may lead to a discovering of novel antioxidants compounds during the extraction by this technique.

  7. Sustainable biodegradation of phenol by Acinetobacter calcoaceticus P23 isolated from the rhizosphere of duckweed Lemna aoukikusa.

    Science.gov (United States)

    Yamaga, Fumiko; Washio, Kenji; Morikawa, Masaaki

    2010-08-15

    Phenol-degrading bacteria were isolated from the rhizosphere of duckweed (Lemna aoukikusa) using an enrichment culture method. One of the isolates, P23, exhibited an excellent ability to degrade phenol and attach to a solid surface under laboratory conditions. Phylogenetic analysis revealed that P23 belongs to the genera Acinetobacter and has the highest similarity to Acinetobacter calcoaceticus. P23 rapidly colonized on the surface of sterilized duckweed roots and formed biofilms, indicating that the conditions provided by the root system of duckweed are favorable to P23. A long-term performance test (160 h) showed that continuous removal of phenol can be attributed to the beneficial symbiotic interaction between duckweed and P23. P23 is the first growth-promoting bacterium identified from Lemna aoukikusa. The results in this study suggest the potential usefulness of dominating a particular bacterium in the rhizosphere of duckweeds to achieve efficient and sustainable bioremediation of polluted water.

  8. Study of the catabolism of thyme phenols combining in vitro fermentation and human intervention.

    Science.gov (United States)

    Mosele, Juana I; Martín-Peláez, Sandra; Macià, Alba; Farràs, Marta; Valls, Rosa-Maria; Catalán, Úrsula; Motilva, María-José

    2014-11-12

    The gut metabolism of four thyme phenolics (monoterpenes thymol and carvacrol, rosmarinic acid, and eriodictyol) was evaluated in vitro. After the in vitro transformations of the individual phenols had been studied, the presence of their microbial metabolites was investigated in human feces collected before and after a sustained intake (3 weeks) of 25 mL/day of a thyme phenol-enriched olive oil. Results of in vitro fermentation showed low degradation of thymol and carvacrol. By contrast, large catabolism was noted when rosmarinic acid and eriodictyol were fermented, yielding hydroxyphenylpropionic acid as the main metabolite. In accordance with these results, after the in vivo intervention with thyme phenol-enriched olive oil, an increase in the concentration of hydroxyphenylpropionic and phenylpropionic acids was observed in human feces, confirming the effective in vivo microbial degradation of rosmarinic acid and eriodictyol. Carvacrol was detected in fecal samples at trace levels, suggesting that monoterpenes are well absorbed in the upper part of the gastrointestinal tract.

  9. Effect of phenolic compounds and osmotic stress on the expression of penicillin biosynthetic genes from Penicillium chrysogenum var. halophenolicum strain

    Directory of Open Access Journals (Sweden)

    Sumaya Ferreira Guedes

    2012-01-01

    Full Text Available Phenol and phenolic compounds are aromatic pollutants that inhibit biological treatment of wastewaters. Penicillium chrysogenum var. halophenolicum is a halotolerant fungus that previously showed the ability to degrade phenol and resorcinol in high salinity conditions. The presence of the penicillin biosynthetic cluster in P. chrysogenum var. halophenolicum was recently described. In this article, we examined the expression of pcbAB, pcbC and penDE, genes responsible for δ-(L-α-aminoadipyl-L-cysteinyl-D-valine synthetase, isopenicillin N synthase and isopenicillin N acyltransferase activities, respectively, in P. chrysogenum var. halophenolicum. A quantitative PCR (qPCR approach was used to determine how these genes were expressed in media with 2% and 5.9% NaCl supplemented with phenol, catechol, hydroquinone and resorcinol as the sole carbon source. The effect of salt on the capability of P. chrysogenum var. halophenolicum to degrade aromatic compounds was measured using HPLC. qPCR analysis of RNA extracted from P. chrysogenum var. halophenolicum indicated that the expression levels of pcbAB, pcbC and penDE decreased in high saline concentrations compared to the levels expressed in media with glucose. High concentrations of salt significantly repress the expression of pcbAB and penDE. The pcbC gene was expressed differentially in catechol containing medium. There was no evident relationship between the expression levels of penicillin biosynthetic genes and yields of penicillin. Meanwhile, the presence of phenol and phenolic compounds seems to positively influence the antibiotic production; high concentrations of salt stimulated penicillin production. These results support the hypothesis that phenol, phenolic compounds and high concentrations of salt could act like a stress factor for P. chrysogenum var. halophenolicum resulting in higher yields of β-lactam antibiotic production.

  10. Exploring the Degradation of Ibuprofen by Bacillus thuringiensis B1(2015b: The New Pathway and Factors Affecting Degradation

    Directory of Open Access Journals (Sweden)

    Ariel Marchlewicz

    2017-10-01

    Full Text Available Ibuprofen is one of the most often detected pollutants in the environment, particularly at landfill sites and in wastewaters. Contamination with pharmaceuticals is often accompanied by the presence of other compounds which may influence their degradation. This work describes the new degradation pathway of ibuprofen by Bacillus thuringiensis B1(2015b, focusing on enzymes engaged in this process. It is known that the key intermediate which transformation limits the velocity of the degradation process is hydroxyibuprofen. As the degradation rate also depends on various factors, the influence of selected heavy metals and aromatic compounds on ibuprofen degradation by the B1(2015b strain was examined. Based on the values of non-observed effect concentration (NOEC it was found that the toxicity of tested metals increases from Hg(II < Cu(II < Cd(II < Co(II < Cr(VI. Despite the toxic effect of metals, the biodegradation of ibuprofen was observed. The addition of Co2+ ions into the medium significantly extended the time necessary for the complete removal of ibuprofen. It was shown that Bacillus thuringiensis B1(2015b was able to degrade ibuprofen in the presence of phenol, benzoate, and 2-chlorophenol. Moreover, along with the removal of ibuprofen, degradation of phenol and benzoate was observed. Introduction of 4-chlorophenol into the culture completely inhibits degradation of ibuprofen.

  11. [Antimicrobic features of phenolic lipids].

    Science.gov (United States)

    Nikolaev, Iu A; Borzenkov, I A; Kalinin, M V; Loĭko, N G; Tarasov, A L; Plakunov, V K; Beliaev, S S; Voronina, N V; Gal'chenko, V F; El'-Registan, G I

    2010-01-01

    The connection between the efficiency of phenolic lipids (PL) and their hydrophobic property (solubility) and hydrophobic property of microorganisms' cell structure is shown. The mixture of amphiphilic di(oxiphenil)-phenil-methanes, which act bacteriostatically under 15 mg/l, possesses maximal efficiency against Staphylococcus aureus. Against Mycobacterium smegmatis with hydrophobic cell wall, hydrophobic 2,4-dialkylocibenzol 70 mg/l was the most effective. Hexylresorcin (HR) stops the development of gram-positive bacteria in concentrations 20-50 mg/l, that of gram-negative bacteria in concentration 65 mg/l, that of M. smegmatis at 70 mg/l, and that of yeast and fungi at 300 mg/l. HR prevails bacteria spores germination in the concentration 25-100 mg/l. The dependence of antibacterial action of isomers and homologues of alkylresorcins on their structure--number, position, and length of alkyl substituents--is studied.

  12. [Inhibition of Denitrification by Total Phenol Load of Coal Gasification Wastewater].

    Science.gov (United States)

    Zhang, Yu-ying; Chen, Xiu-rong; Wang, Lu; Li, Jia-hui; Xu, Yan; Zhuang, You-jun; Yu, Ze-ya

    2016-03-15

    High loaded phenolic pollutants, refractory and high toxic, which existed in coal gasification wastewater, could cause the inhibition of sludge activity. In biological denitrification process of activated sludge treatment system, people tend to focus on the phenol inhibition on the efficiency and activity of nitrifying bacteria while there are few researches on the denitrification process. In order to investigate the inhibition of phenolic compounds from coal gasification wastewater on the denitrification and sludge activity, we used anoxic denitrification system to indentify the influence of different phenol load on denitrification efficiency (removal efficiency of NO₃⁻-N and NO₂⁻-N) as well as the stress and degradation activity of sludge. The results showed that when the concentration of total phenol was changed from 50 mg · L⁻¹ to 200 mg · L⁻¹, the removal rates of NO₃⁻-N and NO₂⁻-N were changed from 55% and 25% to 83% and 83% respectively. In the process of sludge domestication, the characteristics of denitrifying sludge were influenced to a certain degree.

  13. Kinetic model describing the UV/H2O2 photodegradation of phenol from water

    Directory of Open Access Journals (Sweden)

    Rubio-Clemente Ainhoa

    2017-01-01

    Full Text Available A kinetic model for phenol transformation through the UV/H2O2 system was developed and validated. The model includes the pollutant decomposition by direct photolysis and HO•, HO2• and O2 •- oxidation. HO• scavenging effects of CO3 2-, HCO3 -, SO4 2- and Cl- were also considered, as well as the pH changes as the process proceeds. Additionally, the detrimental action of the organic matter and reaction intermediates in shielding UV and quenching HO• was incorporated. It was observed that the model can accurately predict phenol abatement using different H2O2/phenol mass ratios (495, 228 and 125, obtaining an optimal H2O2/phenol ratio of 125, leading to a phenol removal higher than 95% after 40 min of treatment, where the main oxidation species was HO•. The developed model could be relevant for calculating the optimal level of H2O2 efficiently degrading the pollutant of interest, allowing saving in costs and time.

  14. Improvement of phenol photodegradation efficiency by a combined g-C3N4/Fe(III)/persulfate system.

    Science.gov (United States)

    Hu, Jian-Yang; Tian, Ke; Jiang, Hong

    2016-04-01

    Graphite-like C3N4 (g-C3N4) is an efficient visible-light-driven photocatalyst commonly used in dye decolorization with very poor photocatalytic efficiency for degrading recalcitrant organic pollutants, such as phenol. In this study, we designed a g-C3N4/Fe(III)/persulfate system to significantly improve the phenol photodegradation efficacy by combining photocatalysis and light Fenton interaction. The phenol removal ratio and degradation rate of the g-C3N4/Fe(III)/persulfate system are 16.5- and 240-fold higher than those of individual g-C3N4 system. Sulfate radicals [Formula: see text] and H2O2 are detected in the g-C3N4/Fe(III)/persulfate system, suggesting that both radical decomposition and light Fenton interaction play important roles in phenol degradation. The efficient coupled photocatalytic system of g-C3N4 combined with Fe(III) and persulfate shows significant potential for application in large-scale degradation of environmental pollutants. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Comparison of Sonolysis, Photolysis, and Photosonolysis for the Degradation of Organic Matter

    Directory of Open Access Journals (Sweden)

    Afshin Maleki

    2009-06-01

    Full Text Available Phenol is one of the most common compounds found in the effluents of many industries such as petroleum refining and petrochemicals, pharmaceuticals, pesticides, paint and dye industries, organic chemicals manufacturing, etc. Due to the high toxicity of phenol, the contamination of bodies of water with this chemical is a serious problem for the environment and human health. In this study, the sonochemical, photochemical, and photosonochemical degradation of phenol in an aqueous solution were investigated. The sonochemical and photochemical experiments were carried out using a bath sonicator (500 W working at 35 and 130 kHz frequencies and a 400W medium pressure UV lamp. Experiments were performed at initial concentrations varying from 1 to 100 mg L-1. The effects of such parameters as pH, initial phenol concentration, and oxidation period have been determined. Results showed that the effects of ultrasound wave for phenol oxidation were mainly due to hydroxyl radical production during cavitation-induced water decomposition. However, low rates of sonochemical destruction of phenol in water solution obtained. In the sonochemical process, phenol underwent degradation at a faster rate at 130 kHz than 35 kHz. Besides, it was shown that reaction rates involving hydroxyl radicals (hydrogen peroxide formation and phenol oxidation had a maximum value at higher frequencies. The best yield was observed at 130 kHz for phenol degradation perhaps due to the greater availability of hydroxyl radical on the outer surface of cavitation bubbles. It was found that the rate of photochemical degradation of phenol was higher than sonochemical destruction. Also, the results showed that the combination of ultrasound wave and ultraviolet irradiation was considerably more effective than either ultrasound or ultraviolet light alone. Thus, based on the results of this study, the synergistic action of ultrasound and ultraviolet light is confirmed. This may be the result of

  16. Inhibition of ethanol-producing yeast and bacteria by degradation products produced during pre-treatment of biomass

    DEFF Research Database (Denmark)

    Klinke, H.B.; Thomsen, A.B.; Ahring, Birgitte Kiær

    2004-01-01

    degradation, phenol monomers from lignin degradation are important co-factors in hydrolysate inhibition, and inhibitory effects of these aromatic compounds on different ethanol producing microorganisms is reviewed. The furans and phenols generally inhibited growth and ethanol production rate (Q......(EtOH)) but not the ethanol yields (Y-EtOH) in Saccharomyces cerevisiae. Within the same phenol functional group (aldehyde, ketone, and acid) the inhibition of volumetric ethanol productivity was found to depend on the amount of methoxyl substituents and hence hydrophobicity (log P). Many pentose-utilizing strains...

  17. Introducing the Moon's Orbital Eccentricity

    Science.gov (United States)

    Oostra, Benjamin

    2014-11-01

    I present a novel way to introduce the lunar orbital eccentricity in introductory astronomy courses. The Moon is perhaps the clearest illustration of the general orbital elements such as inclination, ascending node, eccentricity, perigee, and so on. Furthermore, I like the students to discover astronomical phenomena for themselves, by means of a guided exercise, rather than just telling them the facts.1 The inclination and nodes may be found by direct observation, monitoring carefully the position of the Moon among the stars. Even the regression of the nodes may be discovered in this way2 To find the eccentricity from students' observations is also possible,3 but that requires considerable time and effort. if a whole class should discover it in a short time, here is a method more suitable for a one-day class or home assignment. The level I aim at is, more or less, advanced high school or first-year college students. I assume them to be acquainted with celestial coordinates and the lunar phases, and to be able to use algebra and trigonometry.

  18. Introducing Physician Assistants to Ontario

    Directory of Open Access Journals (Sweden)

    Meredith Vanstone

    2014-02-01

    Full Text Available In 2006, the Ontario Ministry of Health and Long-Term Care (MOHLTC introduced Physician Assistants (PAs through the announcement of demonstration projects, education and training programs, and subsequent funding. PAs are directly supervised by physicians and act as physician extenders by performing acts as delegated to them by their supervising physicians. PAs were proposed as a potential solution to help improve access to health care and reduce wait times throughout the province. Prior to the 2006 Ministry announcement, there was little public discussion regarding the acceptance of the PA role or its sustainability. Opposition from nursing and other groups emerged in response to the 2006 announcement and flared again when stakeholder comments were solicited in 2012 as part of the PA application for status as regulated health professionals. As a health reform, the introduction of PAs has neither succeeded nor failed. In 2013, the majority of PA funding continues to be provided by the MOHLTC, and it is unknown whether the PA role will be sustainable when the MOHTLC withdraws salary funding and health system employers must decide whether or not to continue employing PAs at their own expense.

  19. Development of a phenol-enriched olive oil with phenolic compounds from olive cake.

    Science.gov (United States)

    Suárez, Manuel; Romero, Maria-Paz; Motilva, Maria-José

    2010-10-13

    The recent information regarding the healthy properties of virgin olive oil phenols and the interest in increasing the value of byproducts from the oil extraction processs support the standardized development of phenol-enriched olive oil. Accordingly, the aim of this research work was to evaluate strategies for the development of a virgin olive oil enriched with phenolic compounds obtained from olive cake to increase phenolic ingestion without the drawback of a higher calorie intake. For this proposal, different combinations of phenolic extracts were evaluated at a range of concentrations to obtain the best prototype of enriched olive oil. To study the functionality of the phenol enrichments, the total phenolic content and the oxidative stability were determined by the Folin-Ciocalteu and Rancimat tests, respectively. In addition, the phenolic composition and antioxidant capacity (ORAC assay) of the oils were studied. Finally, the stability and potential bioaccesibility of the phenolic fraction of the enriched oils were tested by an in vitro gastrointestinal digestion model. Results of the study showed different strategies to select the best prototype of enriched olive oil, taking into consideration not only their phenolic content but also other important factors such as the feasibility of implementing the preparation process in the food industry.

  20. Insights into lignin degradation and its potential industrial applications.

    Science.gov (United States)

    Abdel-Hamid, Ahmed M; Solbiati, Jose O; Cann, Isaac K O

    2013-01-01

    Lignocellulose is an abundant biomass that provides an alternative source for the production of renewable fuels and chemicals. The depolymerization of the carbohydrate polymers in lignocellulosic biomass is hindered by lignin, which is recalcitrant to chemical and biological degradation due to its complex chemical structure and linkage heterogeneity. The role of fungi in delignification due to the production of extracellular oxidative enzymes has been studied more extensively than that of bacteria. The two major groups of enzymes that are involved in lignin degradation are heme peroxidases and laccases. Lignin-degrading peroxidases include lignin peroxidase (LiP), manganese peroxidase (MnP), versatile peroxidase (VP), and dye-decolorizing peroxidase (DyP). LiP, MnP, and VP are class II extracellular fungal peroxidases that belong to the plant and microbial peroxidases superfamily. LiPs are strong oxidants with high-redox potential that oxidize the major non-phenolic structures of lignin. MnP is an Mn-dependent enzyme that catalyzes the oxidation of various phenolic substrates but is not capable of oxidizing the more recalcitrant non-phenolic lignin. VP enzymes combine the catalytic activities of both MnP and LiP and are able to oxidize Mn(2+) like MnP, and non-phenolic compounds like LiP. DyPs occur in both fungi and bacteria and are members of a new superfamily of heme peroxidases called DyPs. DyP enzymes oxidize high-redox potential anthraquinone dyes and were recently reported to oxidize lignin model compounds. The second major group of lignin-degrading enzymes, laccases, are found in plants, fungi, and bacteria and belong to the multicopper oxidase superfamily. They catalyze a one-electron oxidation with the concomitant four-electron reduction of molecular oxygen to water. Fungal laccases can oxidize phenolic lignin model compounds and have higher redox potential than bacterial laccases. In the presence of redox mediators, fungal laccases can oxidize non-phenolic

  1. Photo- and thermal degradation of olive oil measured using an optical fibre smartphone spectrofluorimeter

    Science.gov (United States)

    Hossain, Md Arafat; Canning, John; Cook, Kevin; Ast, Sandra; Jamalipour, Abbas

    2017-04-01

    Degradation of olive oil under light and heat are analysed using an optical fibre based low-cost portable smartphone spectrofluorimeter. Visible fluorescence bands associated with phenolic acids, vitamins and chlorophyll centred at λ 452, 525 and 670 nm respectively are generated using near-UV excitation (LED λex 370 nm), of extra virgin olive oil are degraded more likely than refined olive oil under light and heat exposure. Packaging is shown to be critical when assessing the origin of degradation.

  2. Introducing Science to undergraduate students

    Directory of Open Access Journals (Sweden)

    P. Avila Jr

    2006-07-01

    Full Text Available The knowledge of scientific method provides stimulus and development of critical thinking and logical analysis of information besides the training of continuous formulation of hypothesis to be applied in formal scientific issues as well as in everyday facts. The scientific education, useful for all people, is indispensable for the experimental science students. Aiming at the possibility to offer a systematic learning of the scientific principles, we developed a undergraduate course designed to approximate the students to the procedures of scientific production and publication. The course was developed in a 40 hours, containing two modules: I. Introducing Scientific Articles (papers and II. Writing Research Project. The first module deals with: (1 the difference between scientific knowledge and common sense; (2 scientific methodology; (3 scientific publishing categories; (4 logical principles; (5 deduction and induction approach and (6 paper analysis. The second module includes (1 selection of problem to be solved by experimental procedures; (2 bibliography revision; (3 support agencies; (4 project writing and presentation and (5 critical analysis of experimental results. The course used a Collaborative Learning strategy with each topic being developed through activities performed by the students. Qualitative and quantitative (through Likert questionnaires evaluation were carried out in each step of the course, the results showing great appreciation by the students. This is also the opinion of the staff responsible for the planning and development of the course, which is now in its second and improved version.

  3. Synthesis of Magnetic Carbon Supported Manganese Catalysts for Phenol Oxidation by Activation of Peroxymonosulfate

    Directory of Open Access Journals (Sweden)

    Yuxian Wang

    2016-12-01

    Full Text Available Magnetic core/shell nanospheres (MCS were synthesized by a novel and facile one-step hydrothermal method. Supported manganese oxide nanoparticles (Fe3O4/C/Mn were obtained from various methods (including redox, hydrothermal and impregnation using MCS as the support material and potassium permanganate as the precursor of manganese oxide. The Mn/MCS catalysts were characterized by a variety of characterization techniques and the catalytic performances of Fe3O4/C/Mn nanoparticles were tested in activation of peroxymonosulfate to produce reactive radicals for phenol degradation in aqueous solutions. It was found that Fe3O4/C/Mn catalysts can be well dispersed and easily separated from the aqueous solutions by an external magnetic field. Kinetic analysis showed that phenol degradation on Fe3O4/C/Mn catalysts follows the first order kinetics. The peroxymonosulfate activation mechanism by Fe3O4/C/Mn catalysts for phenol degradation was then discussed.

  4. Bursting in the Belousov-Zhabotinsky Reaction added with Phenol in a Batch Reactor

    International Nuclear Information System (INIS)

    Cadena, Ariel; Agreda, Jesus; Barragan, Daniel

    2013-01-01

    The classic Belousov-Zhabotinski reaction was modified by adding phenol as a second organic substrate that kinetically competes with the malonic acid in the reduction of Ce 4+ to Ce 3+ and in the removal of molecular bromine of the reaction mixture. The oscillating reaction of two substrates exhibited burst firing and an oscillatory period of long duration. Analysis of experimental data shows an increasing of the bursting phenomenon, with a greater spiking in the burst firing and with a longer quiescent state, as a function of the initial phenol concentration increase. It was hypothesized that the bursting phenomenon can be explained introducing a redox cycle between the reduced phenolic species (hydroxyphenols) and the oxidized ones (quinones). The hypothesis was experimentally and numerically tested and from the results it is possible to conclude that the bursting phenomenon exhibited by the oscillating reaction of two substrates is mainly driven by a p-di-hydroxy-benzene/p-benzoquinone redox cycle (author)

  5. Investigation of phytochemical constituents, phenolic profiles and antioxidant activities of ricegrass juice compared to wheatgrass juice

    Directory of Open Access Journals (Sweden)

    Rattanamanee Chomchan

    2016-10-01

    Full Text Available Background: Cereal grass has been brought attention as a new functional food. Wheatgrass juice was known as a super food which provides lots of advantages for human health. However, the young stage of rice sprout has not been made widely known for consumption, though it is in the similar family to wheat (Poaeceae. Accordingly, ricegrass juice can and should be introduced, especially in Asian countries, as an economical functional drink. Nevertheless, currently there is none of the apparent evidences which confirm the nutritive values of ricegrass juice compared to wheatgrass juice. Objective: To investigate the chemical compositions, major phytochemical constituents, bioactive compounds content, specific phenolic profiles, and in vitro antioxidant activities of ricegrass juice compared to wheatgrass juice. Methods: Rice and wheat seeds were germinated and grown hydroponically for 8 days. Both fresh plants were determined for chemical compositions. Next, the grasses were extracted with water, centrifuged, and the supernatants were tested for chlorophyll, carotenoid, and ascorbic acid contents. The left-over supernatant were freeze-dried. The extracts were then screened for the main group of phytochemicals, total extractable phenolic and specific phenolic compounds. Lastly, the extracts were tested for the antioxidant activities using DPPH, ABTS, FRAP, FCA and HRSA. Results: Data revealed that wheatgrass contained higher levels of protein and fat. Both ricegrass and wheatgrass juice extract exhibited the group of phenol, tannin and saponin but not alkaloid, flavonoid, sterol, terpenoid, courmarin, and cardiac glycoside. Wheatgrass juice can be detected for higher level of ascorbic acid and chlorophyll. Both grass juices were found the similar phenolic acids analyzed by HPLC included pyrogallol, vanilic acid, syringic acid and ferulic acid, however, ricegrass juice contained larger amounts of all phenolic acids excluding syringic acid. Conversely

  6. Efficient Enzymatic Synthesis of Phenolic Ester by Increasing Solubility of Phenolic Acids in Ionic Liquids

    DEFF Research Database (Denmark)

    Yang, Zhiyong; Guo, Zheng; Xu, Xuebing

    Compounds from phenolic acid family are well known natural antioxidants, but the application of phenolic acids as antioxidants in industry is limited due to the relatively low solubility in oil-based media. The properties of phenolic acids can be modified through enzymatic lipophilization...... and modified phenolic acids will have amphiphilic property, therefore they can be localized at oil-water or water-oil phase where oxidation is considered to occur frequently. It had been reported that immobilized Candida Antarctica lipase B was the most effective biocatalyst for the various esterification...... reactions, and it had been widely used for esterification of various phenolic acids with fatty alcohol or triglycerides. However, the conversion of phenolic acids is low due to low solubility in hydrophobic solvents and hindrance effect of unsaturated side chain towards the enzyme. Our studies show...

  7. Impact of nanoclay dispersed phenol formaldehyde/fumed silica nanocomposites on physico-mechanical and thermal properties

    Science.gov (United States)

    Lai, Josephine Chang Hui; Rahman, Md. Rezaur; Hamdan, Sinin

    2017-12-01

    In this study, the physical, mechanical and thermal properties of phenol formaldehyde/fumed silica/nanoclay (PF/FS/clay) nanocomposites were investigated. PF/FS/clay nanocomposites were prepared via condensation polymerization method and the effect of different clays as compatibilizers were subsequently investigated. The properties of nanocomposites were characterized through Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), Thermogravimetric Analysis (TGA) and tensile test. FT-IR results confirmed the condensation polymerization and the formation of nanocomposites. SEM result revealed that the surface-modified clay (1.34TCN) had better compatibility with PF/FS matrix compared to surface-modified clay (1.28E), clay (1.30E) and clay (1.31PS). Besides, clay (1.34TCN)-loaded nanocomposites showed better surface morphology among all the nanocomposites. Furthermore, PF/FS/clay (1.34TCN) nanocomposite exhibited better tensile strength and modulus up to 68% due to the strong interfacial bonding between the polymer matrix and fillers. Thermal stability of PF/FS/clay (1.34TCN) nanocomposite showed the highest weight percent loss at the final degradation stage with higher activation energy. Overall, this study proved that clay (1.34TCN) was the most suitable to be introduced in PF/FS matrix.

  8. Operationalizing measurement of forest degradation

    DEFF Research Database (Denmark)

    Dons, Klaus; Smith-Hall, Carsten; Meilby, Henrik

    2015-01-01

    Quantification of forest degradation in monitoring and reporting as well as in historic baselines is among the most challenging tasks in national REDD+ strategies. However, a recently introduced option is to base monitoring systems on subnational conditions such as prevalent degradation activities....... In Tanzania, charcoal production is considered a major cause of forest degradation, but is challenging to quantify due to sub-canopy biomass loss, remote production sites and illegal trade. We studied two charcoal production sites in dry Miombo woodland representing open woodland conditions near human...... settlements and remote forest with nearly closed canopies. Supervised classification and adaptive thresholding were applied on a pansharpened QuickBird (QB) image to detect kiln burn marks (KBMs). Supervised classification showed reasonable detection accuracy in the remote forest site only, while adaptive...

  9. Phenol and Its Toxicity: A Case Report

    Directory of Open Access Journals (Sweden)

    Mahesh Chand Meena

    2014-12-01

    Full Text Available Background: Phenol and its derivatives like dinitrophenol and pentachlorophenol (carbolic acid are widely used as insecticides, but they are very toxic substances. Phenol is a general protoplasmic poison with corrosive local effects that denature proteins. Poisoning with phenol compounds may occur by ingestion, inhalation, and absorption through skin. In this report we presented the toxicity effects of Phenol and its derivatives like dinitrophenol and pentachlorophenol on humans. Case report: A 27-year-old married female was found unconscious at her residence in September 2013. She was expired after hospitalization in Lady Hardinge Medical College and its associated hospital on the same day after six hours. On examination, corrosion of skin, at angel of mouth and chin, and brown discoloration in mucosa of the esophagus were seen. Histological examination showed exfoliation of esophageal mucosa and coagulative necrosis of gastric mucosa. In toxicological analyses, carbolic acid was detected. Conclusion: Strict precautionary measures are advised when using this compound.

  10. Spectroscopic properties of pharmacologically active phenols

    Science.gov (United States)

    Tolstorozhev, G. B.; Skornyakov, I. V.; Bel'kov, M. V.; Shadyro, O. I.; Polozov, G. I.; Sorokin, V. L.; Ksendzova, G. A.

    2012-05-01

    The IR Fourier-transform spectra of pharmacologically active phenol molecules in solutions in CCl4 and in the crystalline state have been studied. Phenol derivatives with different directivities and different levels of pharmacological efficiency have been examined. Based on analysis of the IR spectra of screened phenols, the antimicrobial activity of phenols with free hydroxyl groups has been shown to be highest. The high antimicrobial activity of aminophenols is related to the formation of intramolecular hydrogen bonds. For aminophenols that are active against herpesviruses, O-H...N hydrogen bonds are formed in molecules. The main characteristic of the high antiviral activity against A-type influenza is predominance of intramolecular hydrogen bonds of the O-H...O=C type in molecules. Sulfur-containing aminophenols, which manifest activity against HIV infection, are characterized by the occurrence of hydrogen bonds that involve the participation of the OH, NH, and SO2 groups.

  11. Profile, antioxidant potential, and applicability of phenolic ...

    African Journals Online (AJOL)

    Aghomotsegin

    2015-10-14

    ) of Spirulina platensis and assesses their antioxidant potential, applying them as a natural conservative in minimally processed apples. The phenolic extract showed 396 µg g-1 gallic acid, 347 µg g-1 of caffeic acid, 54 µg g-1.

  12. Use of Modified Phenolic Thyme Extracts (Thymus vulgaris) with Reduced Polyphenol Oxidase Substrates as Anthocyanin Color and Stability Enhancing Agents.

    Science.gov (United States)

    Aguilar, Oscar; Hernández-Brenes, Carmen

    2015-12-14

    Residual enzymatic activity in certain foods, particularly of polyphenoloxidase (PPO), is responsible for the majority of anthocyanin degradation in food systems, causing also parallel losses of other relevant nutrients. The present work explored the feasibility of modifying phenolic profiles of thyme extracts, by use of chromatographic resins, to obtain phenolic extracts capable of enhancing anthocyanin colour and stability in the presence of PPO activity. Results indicated that pretreatment of thyme extracts with strong-anion exchange resins (SAE) enhanced their copigmentation abilities with strawberry juice anthocyanins. Phenolic chromatographic profiles, by HPLC-PDA, also demonstrated that thyme extracts subjected to SAE treatments had significantly lower concentrations of certain phenolic compounds, but extracts retained their colour enhancing and anthocyanin stabilization capacities though copigmentation. Additional testing also indicated that SAE modified extract had a lower ability (73% decrease) to serve as PPO substrate, when compared to the unmodified extract. Phenolic profile modification process, reported herein, could be potentially used to manufacture modified anthocyanin-copigmentation food and cosmetic additives for colour-stabilizing applications with lower secondary degradation reactions in matrixes that contain PPO activity.

  13. Use of Modified Phenolic Thyme Extracts (Thymus vulgaris with Reduced Polyphenol Oxidase Substrates as Anthocyanin Color and Stability Enhancing Agents

    Directory of Open Access Journals (Sweden)

    Oscar Aguilar

    2015-12-01

    Full Text Available Residual enzymatic activity in certain foods, particularly of polyphenoloxidase (PPO, is responsible for the majority of anthocyanin degradation in food systems, causing also parallel losses of other relevant nutrients. The present work explored the feasibility of modifying phenolic profiles of thyme extracts, by use of chromatographic resins, to obtain phenolic extracts capable of enhancing anthocyanin colour and stability in the presence of PPO activity. Results indicated that pretreatment of thyme extracts with strong-anion exchange resins (SAE enhanced their copigmentation abilities with strawberry juice anthocyanins. Phenolic chromatographic profiles, by HPLC-PDA, also demonstrated that thyme extracts subjected to SAE treatments had significantly lower concentrations of certain phenolic compounds, but extracts retained their colour enhancing and anthocyanin stabilization capacities though copigmentation. Additional testing also indicated that SAE modified extract had a lower ability (73% decrease to serve as PPO substrate, when compared to the unmodified extract. Phenolic profile modification process, reported herein, could be potentially used to manufacture modified anthocyanin-copigmentation food and cosmetic additives for colour-stabilizing applications with lower secondary degradation reactions in matrixes that contain PPO activity.

  14. Microwave Cure of Phenol-Formaldehyde Adhesive

    OpenAIRE

    高谷, 政広; 田平, 英敏; 岡本, 忠

    2006-01-01

    [Synopsis] Phenol-formaldehyde resin has been used as a versatile material for adhesives and coatings of a wide range of adherends because of its excellent performance in water- resistance, strength against abrasion, and so on. However, it has a drawback of slow rate of cure and relevant emission of formaldehyde gas after bonding. We studied the curing performance under irradiation of microwave for the purpose of looking for a way of accelerating the cure rate of phenol formaldehyde resin. Th...

  15. Berry Phenolics of Grapevine under Challenging Environments

    Directory of Open Access Journals (Sweden)

    Hernâni Gerós

    2013-09-01

    Full Text Available Plant phenolics have been for many years a theme of major scientific and applied interest. Grape berry phenolics contribute to organoleptic properties, color and protection against environmental challenges. Climate change has already caused significant warming in most grape-growing areas of the world, and the climatic conditions determine, to a large degree, the grape varieties that can be cultivated as well as wine quality. In particular, heat, drought and light/UV intensity severely affect phenolic metabolism and, thus, grape composition and development. In the variety Chardonnay, water stress increases the content of flavonols and decreases the expression of genes involved in biosynthesis of stilbene precursors. Also, polyphenolic profile is greatly dependent on genotype and environmental interactions. This review deals with the diversity and biosynthesis of phenolic compounds in the grape berry, from a general overview to a more detailed level, where the influence of environmental challenges on key phenolic metabolism pathways is approached. The full understanding of how and when specific phenolic compounds accumulate in the berry, and how the varietal grape berry metabolism responds to the environment is of utmost importance to adjust agricultural practices and thus, modify wine profile.

  16. Detection of phenols using engineered bacteria

    Science.gov (United States)

    Wise, Arlene A.; Kuske, Cheryl R.; Terwilliger, Thomas C.

    2007-12-04

    Detection of phenols using engineered bacteria. A biosensor can be created by placing a reporter gene under control of an inducible promoter. The reporter gene produces a signal when a cognate transcriptional activator senses the inducing chemical. Creation of bacterial biosensors is currently restricted by limited knowledge of the genetic systems of bacteria that catabolize xenobiotics. By using mutagenic PCR to change the chemical specificity of the Pseudomonas species CF600 DmpR protein, the potential for engineering novel biosensors for detection of phenols has been demonstrated. DmpR, a well-characterized transcriptional activator of the P. CF600's dmp operon mediates growth on simple phenols. Transcription from Po, the promoter heading the dmp operon, is activated when the sensor domain of DmpR interacts with phenol and mono-substituted phenols. By altering the sensor domain of the DmpR, a group of DmpR derivatives that activate transcription of a Po-lacZ fusion in response to eight of the EPA's eleven priority pollutant phenols has been created. The assays and the sensor domain mutations that alter the chemical specificity of DmpR is described.

  17. Phenolic substances in Ailanthus glandulosa Desf

    Directory of Open Access Journals (Sweden)

    Pekala Karolina

    2014-06-01

    Full Text Available The aim of this work was the isolation and identification of phenolic acids from fruit and leaves of Ailanthus glandulosa Desf. The methods used in the isolation and identification of the compounds were: isolation of phenolic acids modified by Ibrahim and Towers, acidic and alkaline hydrolysis by Schmidtlein and Herrmann and identification of phenolic acids in the isolated fraction of two-dimensional thin layer chromatography (TLC on cellulose plates. In the course of the study, the presence of phenolic acids in leaves and fruit of Ailanthus glandulosa Desf was confirmed. Overall, proportions of 15 phenolic acids were found and identified in the analyzed material. These are: gallic acid, ellagic acid, caffeic acid, gentisic acid, protocatechuic acid, p-hydroxybenzoic acid, m-hydroxybenzoic acid, ferulic acid, p-coumaric acid, syryngic acid, vanillic acid, salicylic acid, 2-hydroxy-4- methoxybenzoic acid, 2,5-dimethoxycinnamic, p-hydroxyphenylacetic acid, and 3 other compounds named A, B, C, whose identification was not possible due to the lack of suitable reference patterns. Studies have shown that leaves and fruit of the plant Ailanthus glandulosa Desf. contain a large number of phenolic acids which possess many important pharmacological activities.

  18. Mixed oxides derived from layered double hydroxides as novel catalysts for phenol photodegradation

    Science.gov (United States)

    Puscasu, C. M.; Carja, G.; Mureseanu, M.; Zaharia, C.

    2017-08-01

    The removal of organic pollutants is nowadays a very challenging aspect of the environmental research. There are strong interests to develop novel semiconducting photocatalysts able to efficiently promote advanced oxidation reactions. The development of photocatalysts based on the mixtures of mixed oxides derived from layered double hydroxides (LDHs) - a family of naturally occurring anionic clays - might offer novel environmental-friendly solutions for the cost effective removal of organic pollutants. This work presents ZnO/ZnAl2O4, ZnO/Zn2TiO4 and ZnO/ZnCr2O4 as novel photocatalytic formulations for phenol degradation under UV irradiation. They were obtained by the controlled thermal treatment of the layered double hydroxides matrices (LDHs), as precursors materials, type ZnM-LDH (M = Al3+, Cr3+ or Ti4+). The LDHs were synthesized by the co-precipitation method at a constant pH. Controlled calcination at 650°C gives rise to solutions of mixed metal oxides. The structural and nanoarchitectonics characteristics of the studied catalysts were described by: XRD, SEM/TEM and TG/DTG techniques. Results show that in the photocatalytic process of the phenol degradation from aqueous solutions, ZnO/ZnCr2O4 and ZnO/ZnAl2O4 showed the best performance degrading ∼98% of phenol after 3.5 hs and 5 hs, respectively; while ZnO/Zn2TiO4 has degraded almost 80 % after 7.5 hs of UV irradiation. These results open new opportunities in the development of new cost effective photoresponsive formulations able to facilitate the photo-degradation of the organic pollution as “green” solution for removal of dangerous pollutants.

  19. Phenol Biodegradation by Free and Immobilized Candida tropicalis RETL-Crl on Coconut Husk and Loofah Packed in Biofilter Column

    International Nuclear Information System (INIS)

    Shazryenna, D; Ruzanna, R; Jessica, M S; Piakong, M T

    2015-01-01

    Phenols and its derivatives are environmental pollutant commonly found in many industrial effluents. It is toxic in nature and causes various health hazards. However, they are poorly removed in conventional biological processes due to their toxicity. Immobilization of microbial cells has received increasing interest in the field of waste treatment and creates opportunities in a wide range of sectors including environmental pollution control. Live cells of phenol-degrading yeast, Candida tropicalis RETL-Crl, were immobilized on coconut husk and loofah by adsorption. The immobolized particle was packed into biofilter column which used for continuous treatment of a phenol with initial phenol concentration of 3mM. Both loofah and coconut husk have similar phenol biodegradation rate of 0.0188 gL −1 h −1 within 15 hours to achieve a phenol removal efficiency of 100%. However loofah have lower biomass concentration of 4.22 gL −1 compared to biomass concentration on coconut husk, 4.39 gL −1 . Coconut husk contain higher biomass concentration which makes it better support material than loofah. Fibrous matrices such as loofah and coconut husk provide adequate supporting surfaces for cell adsorption, due to their high specific surface area. Therefore, coconut husk and loofah being an agricultural waste product have the potential to be used as low-cost adsorbent and support matrix for microbial culture immobilization for the removal of organic pollutant from wastewater. (paper)

  20. Radio catalysis application in degradation of complex organic samples

    International Nuclear Information System (INIS)

    Moreno L, A.

    2014-01-01

    The generation of wastewater is a consequence of human activities, industries to be the generators of a large part of these discharges. These contaminated waters can be processed for their remediation; however the recalcitrant organic compounds are hardly removed through conventional treatments applied, so that new technologies have been developed for disposal such as the advanced oxidation technologies or processes. With the aim of the study is to apply ionizing radiation as a method of remediation in wastewater, in this work were carried out experiments of radiolysis and radio catalysis, which are techniques considered advanced oxidation technologies, that consist in irradiate with 60 Co gamma radiation solutions of 4- chloro phenol and methylene blue, applied at different concentrations and using as process control measurements of the compound not degraded by UV-vis spectrophotometry at 507 and 664 nm for 4-chloro phenol and methylene blue respectively. At doses greater than 2.5 kGy were near-zero degradation. Degradation experiments were also conducted by photo catalysis by irradiation with a UV lamp of 354 nm wavelength. For 4-chloro phenol results showed that degradation is efficient (39%). With those previous results, these techniques were applied to degrade complex mixtures of organic compounds from samples of wastewater from a sewage treatment plant, where was considered as process control measurement of the dissolved organic carbon obtained by a spectrophotometric analysis at 254 nm, and a maximum of 26% degradation was obtained by applying 80 kGy. On the other hand, a series of experiments fractionating the irradiations at intervals of 20 kGy to obtain a cumulative dose of 80 kGy, which was 2.8 times greater with respect to degradation by radio catalysis with continuous irradiation. (Author)

  1. Copigmentation effect of phenolic compounds on red currant juice anthocyanins during storage

    Directory of Open Access Journals (Sweden)

    Mirela Kopjar

    2009-01-01

    Full Text Available Copigmentation has been suggested as a main colour stabilising mechanism in plants protecting the coloured flavylium cation from the nucleophilic attack by the water molecule. In this study influence of phenolic compounds addition (catechol, 4-methyl catechol, (+-catechin and gallic acid on stability of red currant juice anthocyanins (copigment:pigment molar ratio 50:1 and 100:1 during 30 days of storage at 4 °C was investigated. Stability of anthocyanins was evaluated through determination of anthocyanins, total colour difference (ΔE*, kinetic parameters and anthocyanin retention. The initial anthocyanin content of red currant juice was 44.34 mg/100 g. During storage degradation of anthocyanins occurred. After storage anthocyanin content of red currant juice was 38.87 mg/100 mL. However, in samples with addition of phenolic compounds degradation was less pronounced due to formation of pigment-copigment complex (i.e. copigmentation. Anthocyanin content in samples with addition of phenolic compounds ranged from 39.2 to 43.83 mg/100 mL, depending on phenolic compound, its concentration and storage time. The lowest degradation was observed when gallic acid was added. Monitoring only λmax of absorption spectrum of juices, one can get incomplete picture of colour stability of red currant juice. It was important to monitor total colour change (ΔE* with CIELAB colour system since all parameters are taken into account. The lowest ΔE*, after 30 days of storage, had samples with addition of catechol and (+-catechin (0.83 and 0.86, respectively, while the highest values had samples with addition of gallic acid (1.26.

  2. Effects of different enzymatic pre-press maceration treatments on the release of phenols into blackcurrant juice

    DEFF Research Database (Denmark)

    Bagger-Jørgensen, Rico; Meyer, Anne Boye Strunge

    2004-01-01

    , and temperature on the total phenol concentration, the juice yield, and on polysaccharide degradation were evaluated for four commercial, fungal enzyme preparations in statistically designed experimental templates. In optimal experimental conditions, treatments with Macer8 [FJ] and Pectinex Ultra SP-L released...... ~6500 and 6650 mg gallic acid equivalents/L of total phenols, respectively. These levels correspond to increases of 14-15% compared to the juice extracted without enzymes, and were significantly higher than those achieved with Rapidase BE Super and Grindamyl pectinase treatments. Increased enzyme dosage...

  3. Thermal degradation of grape marc polyphenols.

    Science.gov (United States)

    Sólyom, Katalin; Solá, Ruth; Cocero, María José; Mato, Rafael B

    2014-09-15

    Bioactive compounds of wine making by-products are of interest in food, cosmetics and pharmaceutical industries. Extraction of antioxidants under mild conditions is time-consuming, giving ground to the development of intensification processes where the operation at high temperature may deteriorate extract quality. This study examined thermal degradation of grape marc and its filtered extract (80, 100 and 150°C). The decrease in anthocyanin content was modelled under non-isothermal conditions by first order kinetics, using the Arrhenius equation. Simulated degradation under isothermal heating showed that the grape marc is more sensitive by one order of magnitude to heat than the filtered extract. This tendency was also confirmed by analyses of the total phenolic content and antioxidant activity. It is suggested that an optimal combination of temperature, treatment time and also raw material environment could be found in process intensification. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Effects of fungal degradation on the CuO oxidation products of lignin: A controlled laboratory study

    Science.gov (United States)

    Hedges, John I.; Blanchette, Robert A.; Weliky, Karen; Devol, Allan H.

    1988-11-01

    Duplicate samples of birch wood were degraded for 0, 4, 8 and 12 weeks by the white-rot fungus, Phlebia tremellosus, and for 12 weeks by 6 other white-rot and brown-rot fungi. P. tremellosus caused progressive weight losses and increased the H/C and O/C of the remnant wood by preferentially degrading the lignin component of the middle lamellae. This fungus increased the absolute (weight loss-corrected) yield of the vanillic acid CuO reaction product above its initial level and exponentially decreased the absolute yields of all other lignin-derived phenols. Total yields of syringyl phenols were decreased 1.5 times as fast as total vanillyl phenol yields. Within both phenol families, aldehyde precursors were degraded faster than precursors of the corresponding ketones, which were obtained in constant proportion to the total phenol yield. Although two other white-rot fungi caused similar lignin compositional trends, a fourth white-rot species, Coriolus versicolor, simultaneously eroded all cell wall components and did not concentrate polysaccharides in the remnant wood. Wood degraded by the three brown-rot fungi exhibited porous cell walls with greatly reduced integrity. The brown-rot fungi also preferentially attacked syringyl structural units, but degraded all phenol precursors at a much slower rate than the white-rotters and did not produce excess vanillic acid. Degradation by P. tremellosus linearly increased the vanillic acid/vanillin ratio, (Ad/Al)v, of the remnant birch wood throughout the 12 week degradation study and exponentially decreased the absolute yields of total vanillyl phenols, total syringyl phenols and the syringyl/vanillyl phenol ratio, S/V. At the highest (Ad/Al)v of 0.50 (12 week samples), total yields of syringyl and vanillyl phenols were decreased by 65% and 80%, respectively, with a resulting reduction of 40% in the original S/V. Many of the diagenetically related compositional trends that have been previously reported for lignins in natural

  5. An antioxidant bioinspired phenolic polymer for efficient stabilization of polyethylene.

    Science.gov (United States)

    Ambrogi, Veronica; Panzella, Lucia; Persico, Paola; Cerruti, Pierfrancesco; Lonz, Carlo A; Carfagna, Cosimo; Verotta, Luisella; Caneva, Enrico; Napolitano, Alessandra; d'Ischia, Marco

    2014-01-13

    The synthesis, structural characterization and properties of a new bioinspired phenolic polymer (polyCAME) produced by oxidative polymerization of caffeic acid methyl ester (CAME) with horseradish peroxidase (HRP)-H2O2 is reported as a new sustainable stabilizer toward polyethylene (PE) thermal and photo-oxidative degradation. PolyCAME exhibits high stability toward decarboxylation and oxidative degradation during the thermal processes associated with PE film preparation. Characterization of PE films by thermal methods, photo-oxidative treatments combined with chemiluminescence, and FTIR spectroscopy and mechanical tests indicate a significant effect of polyCAME on PE durability. Data from antioxidant capacity tests suggest that the protective effects of polyCAME are due to the potent scavenging activity on aggressive OH radicals, the efficient H-atom donor properties inducing free radical quenching, and the ferric ion reducing ability. PolyCAME is thus proposed as a novel easily accessible, eco-friendly, and biocompatible biomaterial for a sustainable approach to the stabilization of PE films in packaging and other applications.

  6. Storage effects on anthocyanins, phenolics and antioxidant activity of thermally processed conventional and organic blueberries.

    Science.gov (United States)

    Syamaladevi, Roopesh M; Andrews, Preston K; Davies, Neal M; Walters, Thomas; Sablani, Shyam S

    2012-03-15

    Consumer demand for products rich in phytochemicals is increasing as a result of greater awareness of their potential health benefits. However, processed products are stored for long-term and the phytochemicals are susceptible to degradation during storage. The objective of this study was to assess the storage effects on phytochemicals in thermally processed blueberries. Thermally processed canned berries and juice/puree were analysed for phytochemicals during their long-term storage. The phytochemical retention of thermally processed blueberries during storage was not influenced by production system (conventional versus organic). During 13 months of storage, total anthocyanins, total phenolics and total antioxidant activity in canned blueberry solids decreased by up to 86, 69 and 52% respectively. In canned blueberry syrup, total anthocyanins and total antioxidant activity decreased by up to 68 and 15% respectively, while total phenolic content increased by up to 117%. Similar trends in phytochemical content were observed in juice/puree stored for 4 months. The extent of changes in phytochemicals of thermally processed blueberries during storage was significantly influenced by blanching. Long-term storage of thermally processed blueberries had varying degrees of influence on degradation of total anthocyanins, total phenolics and total antioxidant activity. Blanching before thermal processing helped to preserve the phytochemicals during storage of blueberries. Copyright © 2011 Society of Chemical Industry.

  7. Application of two bacterial strains for wastewater bioremediation and assessment of phenolics biodegradation.

    Science.gov (United States)

    Paisio, Cintia E; Quevedo, María R; Talano, Melina A; González, Paola S; Agostini, Elizabeth

    2014-08-01

    The use of native bacteria is a useful strategy to decontaminate industrial effluents. In this work, two bacterial strains isolated from polluted environments constitutes a promising alternative since they were able to remove several phenolic compounds not only from synthetic solutions but also from effluents derived from a chemical industry and a tannery which are complex matrices. Acinetobacter sp. RTE 1.4 showed ability to completely remove 2-methoxyphenol (1000 mg/L) while Rhodococcus sp. CS 1 not only degrade the same concentration of this compound but also removed 4- chlorophenol, 2,4-dichlorophenol and pentachlorophenol with high efficiency. Moreover, both bacteria degraded phenols naturally present or even exogenously added at high concentrations in effluents from the chemical industry and a tannery in short time (up to 5 d). In addition, a significant reduction of biological oxygen demand and chemical oxygen demand values was achieved after 7 d of treatment for both effluents using Acinetobacter sp. RTE 1.4 and Rhodococcus sp. CS1, respectively. These results showed that Acinetobacter sp. RTE1.4 and Rhodococcus sp. CS 1 might be considered as useful biotechnological tools for an efficient treatment of different effluents, since they showed wide versatility to detoxify these complex matrices, even supplemented with high phenol concentrations.

  8. Evaluation of copper slag to catalyze advanced oxidation processes for the removal of phenol in water

    International Nuclear Information System (INIS)

    Huanosta-Gutiérrez, T.; Dantas, Renato F.; Ramírez-Zamora, R.M.; Esplugas, S.

    2012-01-01

    Highlights: ► We evaluate the use of an industrial residue (copper slag) as catalyst in water treatment. ► The copper slag was effective to remove organic pollutants (phenol) from water. ► During experimentation, Cu and Fe leaching were not higher than the acceptable levels. ► Slag/H 2 O 2 /UV and slag/H 2 O 2 treatments promoted biodegradability increment of the contaminated water. ► The control of the reaction time would minimize the environmental impact of the produced effluents in terms of acute toxicity. - Abstract: The aim of this work was to evaluate the use of copper slag to catalyze phenol degradation in water by advanced oxidation processes (AOPs). Copper slag was tested in combination with H 2 O 2 (slag/H 2 O 2 ) and H 2 O 2 /UV (slag/H 2 O 2 /UV). The studied methods promoted the complete photocatalytic degradation of phenol. Besides, they were able to reduce about 50% the TOC content in the samples. Slag/H 2 O 2 /UV and slag/H 2 O 2 treatments have favored biodegradability increment along the reaction time. Nevertheless, the irradiated method achieved higher values of the biodegradability indicator (BOD 5 /TOC). The toxicity assessment indicated the formation of more toxic compounds in both treatments. However, the control of the reaction time would minimize the environmental impact of the effluents.

  9. Degradation of lignin β-aryl ether units in Arabidopsis thaliana expressing LigD, LigF and LigG from Sphingomonas paucimobilis SYK-6

    DEFF Research Database (Denmark)

    Mnich, Ewelina; Vanholme, Ruben; Oyarce, Paula

    2017-01-01

    Lignin is a major polymer in the secondary plant cell wall and composed of hydrophobic interlinked hydroxyphenylpropanoid units. The presence of lignin hampers conversion of plant biomass into biofuels; plants with modified lignin are therefore being investigated for increased digestibility....... The bacterium Sphingomonas paucimobilis produces lignin-degrading enzymes including LigD, LigF and LigG involved in cleaving the most abundant lignin inter-unit linkage, the β-aryl ether bond. In this study, we expressed the LigD, LigF and LigG (LigDFG) genes in Arabidopsis thaliana to introduce post......-lignification modifications into the lignin structure. The three enzymes were targeted to the secretory pathway. Phenolic metabolite profiling and 2D HSQC NMR of the transgenic lines showed an increase in oxidized guaiacyl and syringyl units without concomitant increase in oxidized β-aryl-ether units, showing lignin bond...

  10. Experimental Investigation on the Specific Heat of Carbonized Phenolic Resin-Based Ablative Materials

    Science.gov (United States)

    Zhao, Te; Ye, Hong; Zhang, Lisong; Cai, Qilin

    2017-10-01

    As typical phenolic resin-based ablative materials, the high silica/phenolic and carbon/phenolic composites are widely used in aerospace field. The specific heat of the carbonized ablators after ablation is an important thermophysical parameter in the process of heat transfer, but it is rarely reported. In this investigation, the carbonized samples of the high silica/phenolic and carbon/phenolic were obtained through carbonization experiments, and the specific heat of the carbonized samples was determined by a 3D DSC from 150 °C to 970 °C. Structural and compositional characterizations were performed to determine the mass fractions of the fiber and the carbonized product of phenolic which are the two constituents of the carbonized samples, while the specific heat of each constituent was also measured by 3D DSC. The masses of the carbonized samples were reduced when heated to a high temperature in the specific heat measurements, due to the thermal degradation of the carbonized product of phenolic resin in the carbonized samples. The raw experimental specific heat of the two carbonized samples and the carbonized product of phenolic resin was modified according to the quality changes of the carbonized samples presented by TGA results. Based on the mass fraction and the specific heat of each constituent, a weighted average method was adopted to obtain the calculated results of the carbonized samples. Due to the unconsolidated property of the fiber samples which impacts the reliability of the DSC measurement, there is a certain deviation between the experimental and calculated results of the carbonized samples. Considering the similarity of composition and structure, the data of quartz glass and graphite were used to substitute the specific heat of the high silica fiber and carbon fiber, respectively, resulting in better agreements with the experimental ones. Furthermore, the accurate specific heat of the high silica fiber and carbon fiber bundles was obtained by

  11. Efficacy of differently applied tyrosine and tryptophan for modulation of phenolic metabolism in Trachyspermum ammi (L.) sprague seedlings.

    Science.gov (United States)

    Mahmood, Saqib; Mahmood, Tariq; Hussian, Iqbal; Javed, Sadia; Afzal, Beenish; Ghaffar, Freeha; Iqbal, Muhammad; Akram, Muhammad; Ali Shah, Syed Muhammad

    2016-09-01

    Phenolics are pharmaceutically important molecules. Tyrosine and tryptophan are precursors of phenolic metabolism. It was aimed to investigate the potential of exogenously introduced precursors on the phenolic contents in Trachyspermum ammi (L.) Sprague seedlings. The seeds of two local varieties (Chakwal and Desi) were grown in completely randomized design in a growth chamber at 19 ± 2°C with two amino acids (tyrosine and tryptophan) applied (priming and supplementation in rooting medium) at two treatment levels (0, and 1%). Ten days old seedlings were harvested and subjected for growth (root and shoot length, fresh weight and dry weight) and phenolic estimation was done by HPLC method. Presence of seven phenolic acids including quercitin, chromatotropic acid, gallic acid, chlorogenic acid, sinnapic acid, trans 4 hydroxy 3 methoxy cinamic acid and P-courmeric acid was confirmed in both varieties with dissimilar fraction. Poor growth was observed by "Desi" under controlled conditions that were efficiently enhanced by tyrosine and tryptophan treatments. As precursors both amino acids differed for allosteric regulation of the pathway. That varied from application to application and variety to variety too for a pattern of phenolic accumulation. In conclusion, tyrosine and tryptophan application can be useful for farmers for improved growth of T. ammi and for pharmaceutical scientists to modulate metabolites of interest.

  12. Fatal Phenol Toxicity Following Attempted Tattoo Removal.

    Science.gov (United States)

    Li, Zhen; Zhang, Huang; Li, Shu-Hua; Byard, Roger W

    2016-07-01

    Tattoo removal is increasingly required as the number of, particularly young, people acquiring tattoos is increasing. A 21-year-old man is reported who underwent attempted removal of large dragon tattoo utilizing a tattoo machine that injected a phenol-containing solution. At the end of the 3-h procedure, he collapsed and died. At autopsy, large areas of white skin discoloration with focal necrosis and sloughing were present overlying areas of previous tattooing. Histological examination showed collections of eosinophilic fluid with a minimal chronic inflammatory infiltrate in better preserved areas, with focal areas of dermal necrosis. Toxicology was positive for phenol in cardiac blood and liver tissue. There were no underlying organic disease or injuries present which could have caused or contributed to death. This idiosyncratic method of tattoo removal involving subcutaneous injection of phenol had resulted in death most likely from cardiotoxicity. © 2016 American Academy of Forensic Sciences.

  13. Characterization of Phenolic Compounds in Wine Lees.

    Science.gov (United States)

    Zhijing, Ye; Shavandi, Amin; Harrison, Roland; Bekhit, Alaa El-Din A

    2018-03-25

    The effect of vinification techniques on phenolic compounds and antioxidant activity of wine lees are poorly understood. The present study investigated the antioxidant activity of white and red wine lees generated at early fermentation and during aging. In this study, the total phenol content (TPC), total tannin content (TTC), mean degree of polymerization (mDP), and antioxidant activities of five white and eight red wine lees samples from different vinification backgrounds were determined. The results showed that vinification techniques had a significant ( p 35 mg Trolox/g FDM) (PN: Pinot noir lees; FDM: Freeze-dried Material). This study indicates that tannin is one of the major phenolic compounds available in wine lees that can be useful in human and animal health applications.

  14. Phenolic constituents of shea (Vitellaria paradoxa) kernels.

    Science.gov (United States)

    Maranz, Steven; Wiesman, Zeev; Garti, Nissim

    2003-10-08

    Analysis of the phenolic constituents of shea (Vitellaria paradoxa) kernels by LC-MS revealed eight catechin compounds-gallic acid, catechin, epicatechin, epicatechin gallate, gallocatechin, epigallocatechin, gallocatechin gallate, and epigallocatechin gallate-as well as quercetin and trans-cinnamic acid. The mean kernel content of the eight catechin compounds was 4000 ppm (0.4% of kernel dry weight), with a 2100-9500 ppm range. Comparison of the profiles of the six major catechins from 40 Vitellaria provenances from 10 African countries showed that the relative proportions of these compounds varied from region to region. Gallic acid was the major phenolic compound, comprising an average of 27% of the measured total phenols and exceeding 70% in some populations. Colorimetric analysis (101 samples) of total polyphenols extracted from shea butter into hexane gave an average of 97 ppm, with the values for different provenances varying between 62 and 135 ppm of total polyphenols.

  15. Determination of biological activities and total phenolic contents of flowers of jasminum humile and roots of dorema aucheri

    International Nuclear Information System (INIS)

    Khan, A.; Farooq, U.; Ullah, F.; Iqbal, J.

    2014-01-01

    The present study was designed to investigate in vitro antioxidant, NO scavenging, and antibacterial activities as well as total phenolic contents of different extracts of flowers of Jasminum humile and roots of Dorema aucheri. The plant extracts showed significant antioxidant activity, having IC50 values comparable to those of references used in each assay and also inhibited accumulation of nitrite in vitro. The plant extracts yielded phenolic contents and showed significant antibacterial activity. The observed antioxidant potential and phenolic contents of the extracts showed that flowers of J. humile and roots of D. aucheri are potential source of natural antioxidants that may help to retard oxidative degradation and microbial growth in food industry. (author)

  16. Promotion of Phenol Photodecomposition over TiO2 Using Au, Pd, and AuPd Nanoparticles

    DEFF Research Database (Denmark)

    Su, Ren; Tiruvalam, Ramchandra; He, Qian

    2012-01-01

    Noble metal nanoparticles (Au, Pd, AuPd alloys) with a narrow size distribution supported on nanocrystalline TiO2 (M/TiO2) have been synthesized via a sol-immobilization route. The effect of metal identity and size on the photocatalytic performance of M/TiO2 has been systematically investigated...... using phenol as a probe molecule. A different phenol degradation pathway was observed when using M/TiO2 catalysts as compared to pristine TiO2.We propose a mechanism to illustrate how the noble metal nanoparticles enhance the efficiency of phenol decomposition based on photoreduction of p......-benzoquinone under anaerobic conditions. Our results suggest that the metal nanoparticles not only play a role in capturing photogenerated electrons, but are strongly involved in the photocatalytic reaction mechanism. The analysis of the reaction intermediates allows us to conclude that on M/TiO2 undesired redox...

  17. Impact of olive oil phenolic concentration on human plasmatic phenolic metabolites.

    Science.gov (United States)

    Rubió, Laura; Valls, Rosa-M; Macià, Alba; Pedret, Anna; Giralt, Montse; Romero, Maria-Paz; de la Torre, Rafael; Covas, Maria-Isabel; Solà, Rosa; Motilva, Maria-José

    2012-12-15

    Three different functional phenol-enriched virgin olive oils (FVOO) were prepared with a phenolic content of 250 (L-FVOO), 500 (M-FVOO), and 750 mg (H-FVOO) total phenols/kg. In a randomised, cross-over study with 12 healthy volunteers, the pharmacokinetics of phenolic biological metabolites was assessed. An increasing linear trend was observed for hydroxytyrosol sulfate, the main phenolic metabolite quantified in plasma, with C(max) values of 1.35, 3.32, and 4.09 μmol/l, and AUC mean values of 263.7, 581.4, and 724.4 μmol/min for L-FVOO, M-FVOO, and H-FVOO, respectively. From our data an acute intake of phenol-enriched olive oils promotes a dose-dependent response of phenol conjugate metabolites in human plasma. Also, we point out for the first time hydroxytyrosol acetate sulfate as a main biological metabolite of hydroxytyrosol from olive oil ingestion. Copyright © 2012 Elsevier Ltd. All rights reserved.

  18. Degradation of triphenylborane-pyridine antifouling agent in water by copper ions.

    Science.gov (United States)

    Tsuboi, Ai; Okamura, Hideo; Kaewchuay, Netnapit; Fukushi, Keiichi; Zhou, Xiaojian; Nishida, Tomoaki

    2013-01-01

    Triphenylborane-pyridine (TPBP) is an antifouling compound used in Asian countries, including Japan, and its residue has not been detected in aquatic environments to date. There are limited data on its fate for environmental management. The purpose of this study was to evaluate whether TPBP is degraded by metal ions in aquatic environments. TPBP with metal ions in 20 mM sodium acetate buffer at pH 8.0 was placed at 25 degrees C in the dark for 24 h. The concentrations of TPBP and its degradation products, such as diphenylboronic acid, phenylboronic acid (MPB), phenol, benzene, biphenyl, and boron were determined. The presence of copper ions (50 mg/l), but not zinc or manganese ions, resulted in complete degradation of TPBP in 24 h. The TPBP degradation was much faster than the boron production in the initial reaction (0-1 h) with copper salts, depending on the copper salts tested. TPBP was degraded by copper ions (5 mg/l) in 24 h, producing phenol, MPB, biphenyl, and borate. Cu2+ as copper(II) chloride or copper(II) acetate led to complete degradation of TPBP, and thylenediaminetetraacetic acid disodium salt addition suppressed the TPBP degradation. Cu+ as copper(I) acetate also completely degraded TPBP, and bathocuproine addition suppressed the TPBP degradation. This suggests that copper ions existing in natural environments might degrade TPBP released from antifouling paint into water, and this could be one of the important mechanisms to dissipate TPBP residues in aquatic environments.

  19. Irradiation with benzene, toluene and phenol electron beams in aqueous solution; Irradiacion con haces de electrones de benceno, tolueno y fenol en solucion acuosa

    Energy Technology Data Exchange (ETDEWEB)

    Santoyo O, E.L.; Lopez V, H.; Vazquez A, O.; Lizama S, B.E.; Garcia F, M. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1998-07-01

    It is described a methodology for waste water treatment which is simulated doing a benzene-toluene-phenol mixture in aqueous solution. Three different concentrations of them ones were used which were irradiated with electron beams coming from a Pelletron Accelerator carrying out the degradation effect of these compounds in CO{sub 2} and H{sub 2}O. By mean of gas chromatography the analytical determinations were realized finding that in lower concentration of benzene and toluene performances of degradation higher than 95 % were obtained, but higher concentrations (100 ppm) the performance diminishes at 89 %, while for phenol in higher concentrations its degradation is over 60 % and in lower concentrations the degradation is under 80 %. The results are obtained with a constant irradiation time of 12 seconds and neutral pH. (Author.

  20. Optimization of laccase production by two strains of Ganoderma lucidum using phenolic and metallic inducers

    Directory of Open Access Journals (Sweden)

    Francisco Kuhar

    Full Text Available Ganoderma lucidum (Curtis P. Karst is a white rot fungus that is able to degrade the lignin component in wood. The ability of two strains of this species to produce the ligninolytic enzyme laccase was assessed. After the evaluation of induction with heavy metals and phenolic compounds, it was found that among the tested substances, copper and ferulic acid are the best laccase inducers. It was also observed that the two types of inducers (phenolic and metallic produce different electrophoretic patterns of laccase activity. Optimized concentrations of inducers were obtained through a factorial design and the thermal stability of optimized supernatants was studied at a wide range of acidic pH. We found that the enzyme is more thermostable at higher pH values.

  1. Autohydrolysis and organosolv process for recovery of hemicelluloses, phenolic compounds and lignin from grape stalks.

    Science.gov (United States)

    Amendola, D; De Faveri, D M; Egües, I; Serrano, L; Labidi, J; Spigno, G

    2012-03-01

    A combination of two environment-friend processes for hemicelluloses and lignin recovery from red grape stalks were investigated: an autohydrolysis pretreatment at 180°C for 30 min followed by a non-catalysed ethanol organosolv step at 180°C for 90 min. Hemicelluloses were precipitated by ethanol addition to autohydrolysis liquor, while lignin was tentatively precipitated by acidification of liquors from both the processes. Results suggest that stalks hemicelluloses can be easily hydrolysed requiring a milder treatment to reduce sugar degradation, while the organosolv process did not give a consistent delignification. Autohydrolysis allowed a recovery of 2% (on stalks d.m.) of total phenols in the liquor. Organosolv liquor had a higher concentration of phenols (corresponding to 0.72% of stalks d.m.) which almost completely precipitated with lignin. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. The role of nitrite and nitrate ions as photosensitizers in the phototransformation of phenolic compounds in seawater

    Energy Technology Data Exchange (ETDEWEB)

    Calza, P., E-mail: paola.calza@unito.it [Universita degli Studi di Torino, Dipartimento di Chimica, Via P. Giuria 5, 10125 Torino (Italy); Vione, D. [Universita degli Studi di Torino, Dipartimento di Chimica, Via P. Giuria 5, 10125 Torino (Italy); Universita degli Studi di Torino, Centro Interdipartimentale NatRisk, Via Leonardo da Vinci 44, 10095 Grugliasco (Italy); Novelli, A. [Max Planck Institute for Chemistry, 55128 Mainz (Germany); Pelizzetti, E.; Minero, C. [Universita degli Studi di Torino, Dipartimento di Chimica, Via P. Giuria 5, 10125 Torino (Italy)

    2012-11-15

    Nitrite and nitrate are known to be involved in photochemical processes occurring in natural waters. In this study we have investigated the role played by these photosensitizers towards the transformation of xenobiotic organic matter in marine water, with the goal of assessing the typical transformation routes induced in seawater by irradiated nitrite/nitrate. For this purpose, phenol was chosen as model molecule. Phenol transformation was investigated under simulated solar radiation in the presence of nitrite (in the range of 1 Multiplication-Sign 10{sup -5}-1 Multiplication-Sign 10{sup -2} M) or nitrate ions, in pure water at pH 8, in artificial seawater (containing same dissolved salts as seawater but no organic matter), and in natural seawater. In all experiments, phenol degradation rate and formation of intermediates were assessed. As expected, phenol disappearance rate decreased with decreasing nitrite concentration and was slightly reduced by the presence of chloride. Other salts present in artificial seawater (e.g. HCO{sub 3}{sup -}, CO{sub 3}{sup 2-} and Br{sup -}) had a more marked effect on phenol transformation. Analysis of intermediates formed in the different matrices under study showed generation of hydroxyl-, nitro- and chloroderivatives of phenol, to a different extent depending on experimental conditions. 1,4-Benzoquinone prevailed in all cases, nitroderivatives were only formed with nitrite but were not detected in nitrate-spiked solutions. Competition was observed between halogenation and nitration of phenol, with variable outcome depending on nitrite concentration. The most likely reason is competition between nitrating and halogenating species for reaction with the phenoxyl radical. A kinetic model able to justify the occurrence of different intermediates under the adopted conditions is presented and discussed. -- Highlights: Black-Right-Pointing-Pointer Nitrite and nitrate-mediated solar-driven transformations of pollutant in seawater were

  3. Comparing macrophyte herbivory by introduced Louisiana crayfish ...

    African Journals Online (AJOL)

    Comparing macrophyte herbivory by introduced Louisiana crayfish ( Procambarus clarkii ) (Crustacea: Cambaridae) and native Dytiscid beetles ( Cybister tripunctatus ) (Coleoptera: Dytiscidae), in Kenya.

  4. Investigation of Phenol Removal in Aqueous Solutions Using Advanced Photochemical Oxidation (APO

    Directory of Open Access Journals (Sweden)

    Naser Jamshidi

    2010-01-01

    Full Text Available Most organic compounds are resistant to conven­tional chemical and biological treatments. For this reason, other methods are being studied as alter­natives to the biological and classical physico-chemical pro­cesses. In this study, advanced photochemical oxidation (APO processes (UV, UV/H2O2, UV/H2O2/Fe(II, andUV/H2O2/Fe(III were investigated in lab-scale experiments for the degradation of phenol in an aqueous solution. A medium-pressure 300 watt (UV-C mercury ultraviolet lamp was used as the radiation source and H2O2 30% as the oxidant. Phenol (initial concentration= 0.5 mmol/L was selected as the model due to its high use and application. Some important parameters such as pH, H2O2 input concentration, iron catalyst concentration, the type of iron salt, and duration of UV radiation were studied based on the standard methods. The results showed that the Photo-Fenton process was the most effective treatment under acidic conditions producing a higher rate of phenol degradation over a very short radiation time. The process accelerated the oxidation rate by 4-5 times the rate of the UV/H2O2 process. The optimum conditions were obtained at a pH value of 3, with a molar ratio of 11.61 for H2O2/Phenol and molar ratios of 0.083 and 0.067for Iron/H2O2 in the UV/H2O2/Fe (II and the UV/H2O2/Fe (III systems, respectively.

  5. Antibacterial Activity of Phenolic Compounds Against the Phytopathogen Xylella fastidiosa

    OpenAIRE

    Maddox, Christina E.; Laur, Lisa M.; Tian, Li

    2010-01-01

    Xylella fastidiosa is a pathogenic bacterium that causes diseases in many crop species, which leads to considerable economic loss. Phenolic compounds (a group of secondary metabolites) are widely distributed in plants and have shown to possess antimicrobial properties. The anti-Xylella activity of 12 phenolic compounds, representing phenolic acid, coumarin, stilbene and flavonoid, was evaluated using an in vitro agar dilution assay. Overall, these phenolic compounds were effective in inhibiti...

  6. Anticancer activity of selected phenolic compounds: QSAR studies using ridge regression and neural networks.

    Science.gov (United States)

    Nandi, Sisir; Vracko, Marjan; Bagchi, Manish C

    2007-11-01

    -propagation artificial neural network studies have been introduced in the present investigation for a better understanding of multidimensional rational patterns in more complex data sets. The counter-propagation artificial neural network studies were performed on the same data set and with the same descriptors as have been carried out in developing ridge regression models and the result of counter-propagation neural network models produces very interesting findings in terms of leave-one-out test. Finally, an attempt has been made for a comparative study of the relative effectiveness of linear statistical methods versus nonlinear techniques, such as counter-propagation neural networks in modeling structure-activity studies of the phenolic compounds.

  7. Electro oxidation of Phenol on a Ti/RuO{sub 2} anode: effect of some electrolysis parameters

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Iranildes D. dos; Dutra, Achilles J.B. [Universidade Federal do Rio de Janeiro (PEMM/COPPE/UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-Graduacao de Engenharia. Programa de Engenharia Metalurgica e de Materiais; Afonso, Julio C., E-mail: julio@iq.ufrj.b [Universidade Federal do Rio de Janeiro (IQ/UFRJ), RJ (Brazil). Inst. de Quimica. Dept. de Quimica Analitica

    2011-07-01

    The influences of electrolysis time, anodic area, current density and supporting electrolyte on phenol and its byproducts degradation on a Ti/RuO{sub 2} anode were investigated. It was observed that phenol and its byproducts were rapidly broken down in the presence of chloride ions. Gas chromatography/mass spectrometry (GC/MS) data have shown that the presence of chloride ions lead to chlorophenols formation, due to reactions with Cl{sub 2} and/or OCl{sup -} generated during electrolysis. However, these intermediate products were also degraded later by the oxidizing agents. The standards established by the CONAMA (Brazilian National Council for the Environment) for phenols and chlorophenols in effluents were achieved after 360 min of electrolysis with a current density of 10 mA cm-2. Cyclic voltammograms obtained with the anodes before and after 436 h of electrolysis under severe salinity conditions (2 mol L-1) and current density (800 mA cm-2) showed that Ti/RuO{sub 2} did not lose its electrocatalytic properties. This fact indicates that Ti/RuO{sub 2} can be used for the treatment of effluents containing phenols in a chloride environment. (author)

  8. Antiplasmodial activity of some phenolic compounds from ...

    African Journals Online (AJOL)

    Background: Plasmodium falciparum, one of the causative agents of malaria, has high adaptability through mutation and is resistant to many types of anti-malarial drugs. This study presents an in vitro assessment of the antiplasmodial activity of some phenolic compounds isolated from plants of the genus Allanblackia.

  9. Micropropagation and Evaluation of Phenolic Content, Antioxidant ...

    African Journals Online (AJOL)

    Vernonia cinerea, belonging to the family Asteraceae, is of wide medicinal application. This study investigated the antimicrobial, antioxidant activities and the total phenolic contents of wild plant of Vernonia cinerea with its respective shoot cultures.Nodal explants of V. cinerea were cultured on Murashige and Skoog (MS) ...

  10. Physical bonding between sunflower proteins and phenols

    NARCIS (Netherlands)

    Karefyllakis, Dimitris; Altunkaya, Serkan; Berton-Carabin, Claire C.; Goot, van der Atze Jan; Nikiforidis, Constantinos V.

    2017-01-01

    The complexation of proteins with phenolic compounds has been recently considered a promising route to improve the oxidative stability of food dispersions, such as oil-in-water (O/W) emulsions. However, the effect of such a complexation on the functional properties of proteins, such as their

  11. Separation and characterization of phenolic compounds from ...

    African Journals Online (AJOL)

    Terminalia ivoriensis A. Chev. (Combretaceae) is an Ivorian medicinal plant. There is little ethnobotanical and almost no chemical information available for this species. The aim of this study was to isolate phenolic compounds from T. ivoriensis. In this way, its ethyl acetate extract (Ea) was fractionated by silica gel column ...

  12. DROUGHT AFFECTS PROTEIN AND PHENOLIC CONTENT IN ...

    African Journals Online (AJOL)

    userpc

    Department of Biochemistry, Bayero University, Kano, Nigeria. ... Water deficit stress led to significant (P<0.05) increase in total protein content, but total phenolics content in all the landraces increased slightly. Drought stress ... the leaves of drought-stressed plants might be related to the antioxidant defence role of the.

  13. Profile, antioxidant potential, and applicability of phenolic ...

    African Journals Online (AJOL)

    ) of Spirulina platensis and assesses their antioxidant potential, applying them as a natural conservative in minimally processed apples. The phenolic extract showed 396 &µg g-1 gallic acid, 347 µg g-1 of caffeic acid, 54 µg g-1 salicylic acid ...

  14. Antioxidant Capacity, Radical Scavenging Kinetics and Phenolic ...

    African Journals Online (AJOL)

    Antioxidant Capacity, Radical Scavenging Kinetics and Phenolic Profile of Methanol Extracts of Wild Plants of Southern Sonora, Mexico. EF Moran-Palacio, LA Zamora-Álvarez, NA Stephens-Camacho, GA Yáñez- Farías, A Virgen-Ortiz, O Martínez-Cruz, JA Rosas-Rodríguez ...

  15. Production of phenolic compounds from Spirulina maxima ...

    African Journals Online (AJOL)

    The purpose of this study was to illustrate the enhancing process of phenolics synthesis in Spirulina maxima grown in Zarrouk's medium supplemented with different concentration of NaNO3 and/or combined with phenylalanine (L-PA). Also, the protective efficacy of Spirulina polyphenolic (SPP) extracts against ...

  16. Flavonoid, hesperidine, total phenolic contents and antioxidant ...

    African Journals Online (AJOL)

    Additionally, the antioxidant activities were also determined by ferric reducing antioxidant power (FRAP) and 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging activity. C. hystrix had the highest flavonoid and total phenolic contents while C. aurantifolia had the highest hesperidine content. The antioxidant activity of ...

  17. Molecular complexes of phenols with DDQ

    Indian Academy of Sciences (India)

    Abstract. Molecular complexes of phenols with DDQ have been studied spectrophotometrically in the temperature range of 10–30°C in a solvent (CHCl3) of low polarity under low donor concentrations. All the complexes exhibit one CT band each in the wavelength region where acceptor and donor do not have any ...

  18. Characterization of Phenolic Compounds in Wine Lees

    Directory of Open Access Journals (Sweden)

    Ye Zhijing

    2018-03-01

    Full Text Available The effect of vinification techniques on phenolic compounds and antioxidant activity of wine lees are poorly understood. The present study investigated the antioxidant activity of white and red wine lees generated at early fermentation and during aging. In this study, the total phenol content (TPC, total tannin content (TTC, mean degree of polymerization (mDP, and antioxidant activities of five white and eight red wine lees samples from different vinification backgrounds were determined. The results showed that vinification techniques had a significant (p < 0.05 impact on total phenol and tannin content of the samples. White wine lees had high mDP content compared with red ones. Catechin (50–62% and epicatechin contents were the predominant terminal units of polymeric proanthocyanidin extracted from examined samples. Epigallocatechin was the predominant extension unit of white wine lees, whereas epicatechin was the predominant compound in red wine marc. The ORAC (oxygen radical absorbance capacity assay was strongly correlated with the DPPH (α, α-diphenyl-β-picrylhydrazyl assay, and the results showed the strong antioxidant activities associated with red wine lees (PN > 35 mg Trolox/g FDM (PN: Pinot noir lees; FDM: Freeze-dried Material. This study indicates that tannin is one of the major phenolic compounds available in wine lees that can be useful in human and animal health applications.

  19. Stability of lipid encapsulated phenolic acid particles

    Science.gov (United States)

    Phenolic compounds such as ferulic acid and p-coumaric acids are potential bioactive additives for use in animal feeds to replace current antioxidants and antimicrobial compounds. These compounds are ubiquitous in plants and may be obtained from commodity grain crops and waste biomass. Encapsulation...

  20. Interaction of phenolic antioxidants and hydroxyl radicals

    International Nuclear Information System (INIS)

    Wang, W.F.; Luo, J.; Yao, S.D.; Lian, Z.R.; Zhang, J.S.; Lin, N.Y.

    1993-01-01

    Based on pulse radiolysis of aqueous solutions of four phenolic antioxidants including green tea polyphenols, quercetin, caffeic acid and sinapic acid the rate constants for reactions of OH and the antioxidants were determined. Green tea polyphenols and quercetin are the strongest antioxidants. (author)

  1. Interaction of phenolic antioxidants and hydroxyl radicals

    International Nuclear Information System (INIS)

    Wang Wenfeng; Luo Jian; Yao Side; Lian Zhirui; Zhang Jiashan; Lin Nianyun

    1992-01-01

    Based on pulse radiolysis of aqueous solutions of four phenolic antioxidants including green tea polyphenols, quercetin, caffeic acid and sinapic acid the rate constants for reactions of OH and the antioxidants were determined. And green tea polyphenols and quercetin are the strongest antioxidants

  2. Separation and characterization of phenolic compounds from ...

    African Journals Online (AJOL)

    Attioua

    2013-07-03

    Jul 3, 2013 ... (Theobroma cacao). J. Mass Spectrom. 38:35-42. Sanchez R, Jauregui LR, Viladomat B, Codina (2004). Qualitative analysis of phenolic compounds in apple Pomace using liquid chromatography coupled to mass spectrometry in tandem mode. Rapid Communun Mass Spectrom. 18:553-563. Saulo LDS ...

  3. Analysis of phenolic compounds for poultry feeds

    Science.gov (United States)

    Phenolic compounds have generated significant interest recently as feed additives that can impart bioactive characteristics such as anti-oxidant, anti-microbial, and anti-fungal properties to a feed formulation [1-2]. Such natural compounds may offer some preventive benefit to the routine administra...

  4. CORRELATION AMONG PHENOLIC, TOXIC METALS AND ...

    African Journals Online (AJOL)

    Preferred Customer

    KEY WORDS: Toxic metals, Phenols, Flavonoids, Antioxidant activity, Correlation analysis. INTRODUCTION. Humans consume ... treat intestinal worms, fluid retention, poor appetite, and trouble sleeping (insomnia). It is also used as a sedative to ... Treatment of skin diseases, diabetes, anti- hepatotoxic activity. 13, 14. Pot.

  5. Condensed tannins. Structure of the "phenolic scids"

    Science.gov (United States)

    Peter E. Laks; Richard W. Hemingway

    1987-01-01

    Conifer bark-derived condensed tannins can be used in formulating adhesives. Under some extraction conditions and during normal adhesive formulation, the tannin is exposed to strongly alkaline conditions. Alkaline rearrangement results in partial or total rearrangement of tannins of the procyanidin class to "phenolic acids" which have less phloroglucinol...

  6. Yttrium Nitrate mediated Nitration of Phenols at room temperature in ...

    Indian Academy of Sciences (India)

    Rapid nitration of electron rich phenols using Y(NO₃)₃.6H₂O in glacial acetic acid at room temperature was observed with good yield. The method allows nitration of phenols without oxidation, and isolation of nitration product in a rapid and simple way. The described method is selective for phenols.

  7. 40 CFR 721.5908 - Modified phenolic resin (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Modified phenolic resin (generic). 721... Substances § 721.5908 Modified phenolic resin (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as modified phenolic resin (PMN P...

  8. 40 CFR 721.5905 - Modified phenolic resin (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Modified phenolic resin (generic). 721... Substances § 721.5905 Modified phenolic resin (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a modified phenolic resin (PMN...

  9. 40 CFR 721.5762 - Aromatic aldehyde phenolic resin (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Aromatic aldehyde phenolic resin... Specific Chemical Substances § 721.5762 Aromatic aldehyde phenolic resin (generic). (a) Chemical substance... aromatic aldehyde phenolic resin (PMN P-01-573) is subject to reporting under this section for the...

  10. Kinetics of biological treatment of phenolic wastewater in a three ...

    African Journals Online (AJOL)

    Phenolic wastewater was treated in a three-phase draft tube fluidized bed reactor containing biofilm. Phenol removal rate with biofilm was evaluated both theoretically and experimentally. The results indicate that biodegradation of phenolic wastewater by biofilm process could be treated as a zero order reaction.

  11. Preparation of novolacs using phenolic rich components as partial ...

    African Journals Online (AJOL)

    The possibility of using phenolic rich components (water insoluble fraction) from biomass pyrolysis oil as partial substitute of phenol in synthesis of high-ortho phenolic novolac under the catalyst of HCl/Zn(AC)2 has been proved using differential scanning calorimetry (DSC) and Fourier transformed infrared spectroscopy ...

  12. Exploring antioxidant reactivity and molecular structure of phenols ...

    Indian Academy of Sciences (India)

    Phenolic compounds can be considered as themost important bioactive compounds in Mediterranean diet. However, many of the complex connections between phenols antioxidant reactivity and their molecular structure remain unsolved. To shine light on these issues, the antioxidant reactivity of 15 relevant phenolic ...

  13. [Production, absorption and excretion of phenols in intestinal obstruction].

    Science.gov (United States)

    Kawamoto, M

    1986-11-01

    In intestinal obstruction, phenols were produced in the distended loop proximal to obstruction by enteric bacteria. Clinically, in 17 cases of non-strangulated intestinal obstruction, phenols were detected in 15 cases and mean concentration of phenols was 4.2 +/- 9.7 micro g/ml(mean +/- 1 SD). In the fraction of phenols, p-cresol was detected in 15 cases and mean concentration was 3.8 +/- 7.7 and phenol was detected in 4 cases and mean concentration was 0.5 +/- 2.6. Phenols were decreased as clinical improvement of intestinal obstruction. Enteric bacteria in enteric juice ranged from 10(4) to 10(10)/ml and its change paralleled to phenols concentration. Mean urinary concentration of phenols in intestinal obstruction was increased to 297 +/- 415 mg/day compared to control (less than 50 mg/day). Its change also paralleled to phenols concentration in enteric juice. Closed ileal loop was made in dogs and phenols were infused in the loop. Phenols were increased in the portal vein 5 min after the infusion and in the femoral vein 60 min after the infusion. Phenols, which was thought to be toxic to the host, were proved to be produced in the distended intestine and excreted from the kidney.

  14. Characterization of Chlorinated Solvent Degradation Profile Due to Microbial and Chemical Processes in a Constructed Wetland

    National Research Council Canada - National Science Library

    Sobolewski, Teresa

    2004-01-01

    .... With their upward flow capability it is possible to introduce an aerobic and anaerobic environment with a consortium of microorganisms available to degrade the contaminants to within acceptable...

  15. Paraplegia after intercostal neurolysis with phenol

    Directory of Open Access Journals (Sweden)

    Gollapalli L

    2014-11-01

    Full Text Available Lakshman Gollapalli, Rudramanaidu Muppuri Department of Anesthesiology and Pain Medicine, Wayne State University/Detroit Medical Center, Detroit, MI, USA Abstract: In patients with advanced stages of cancer, severe pain is commonly encountered and is very difficult to treat. It affects the quality of life of the patient and the families involved. Pain can be managed using analgesics and adjuvant therapy. However, studies have shown that at least 10%–15% of patients fail to control pain adequately and will experience severe pain. We discuss the case of a 66-year-old female with metastatic adenoid cystic carcinoma of the left submandibular gland and developed paraplegia following intercostal neurolysis with phenol. After a successful diagnostic T6 to T12 intercostal nerve block, the patient was scheduled for an intercostal neurolytic block. We injected 2 mL of 10% aqueous phenol at each level on the left from the T6 to T12 ribs. One hour after the procedure, the patient developed bilateral lower extremity weakness with difficulty moving. A physical examination showed the absence of sensation to pinpricks and vibration from T10 to S5 and an absence of anal sphincter tone and sensation. Magnetic resonance images of the thoracic and lumbar spine showed leptomeningeal metastatic disease and myelitis. We postulate that the paraplegia could be from phenol diffusing along either the spinal nerves or the paravertebral venous plexus into the subarachnoid space. This case report points to the risks involved with phenol neurolysis close to the spine, and we propose alternative methods to minimize neurological complications. Keywords: intercostal neurolysis, pain, phenol, paraplegia 

  16. PEM fuel cell degradation

    Energy Technology Data Exchange (ETDEWEB)

    Borup, Rodney L [Los Alamos National Laboratory; Mukundan, Rangachary [Los Alamos National Laboratory

    2010-01-01

    The durability of PEM fuel cells is a major barrier to the commercialization of these systems for stationary and transportation power applications. While significant progress has been made in understanding degradation mechanisms and improving materials, further improvements in durability are required to meet commercialization targets. Catalyst and electrode durability remains a primary degradation mode, with much work reported on understanding how the catalyst and electrode structure degrades. Accelerated Stress Tests (ASTs) are used to rapidly evaluate component degradation, however the results are sometimes easy, and other times difficult to correlate. Tests that were developed to accelerate degradation of single components are shown to also affect other component's degradation modes. Non-ideal examples of this include ASTs examining catalyst degradation performances losses due to catalyst degradation do not always well correlate with catalyst surface area and also lead to losses in mass transport.

  17. Enhanced biodegradation of mixed phenol and sodium salicylate by Pseudomonas putida in membrane contactors.

    Science.gov (United States)

    Juang, Ruey-Shin; Tsai, Shang-Yuan

    2006-11-01

    A polypropylene (PP) hollow fiber membrane contactor was used as a reactor to enhance the biodegradation of equimolar phenol and sodium salicylate (SA) by Pseudomonas putida CCRC 14365 at 30 degrees C and pH 7. Experiments were performed at a fixed initial cell density of 0.025 g/L and in the total substrate level range 5.32-63.8 mM. The degradation experiments by free cells were also studied for comparison. With pristine hydrophobic fibers, the degradation of SA was started only after phenol was completely consumed. Substrate inhibitory effect was avoided due to sufficiently low substrate levels in the cell medium; however, the biodegradation was time consuming. With ethanol-wetted fibers, both substrates were completely degraded much faster than the use of pristine fibers. Although the wetted fibers were unable to prevent movement of substrates through the pores, biofilm formed on the outer surfaces of the fibers could enhance the tolerance limit of substrate toxicity. This greatly extended the treatment range to high-level substrate mixtures, as long as the water was nearly neutral and free of concentrated inorganic salts.

  18. Directional liquefaction of biomass for phenolic compounds and in situ hydrodeoxygenation upgrading of phenolics using bifunctional catalysts

    Science.gov (United States)

    Junfeng Feng; Chung-yun Hse; Kui Wang; Zhongzhi Yang; Jianchun Jiang; Junming Xu

    2017-01-01

    Phenolic compounds derived from biomass are important feedstocks for the sustainable production of hydrocarbon biofuels. Hydrodeoxygenation is an effective process to remove oxygen-containing functionalities in phenolic compounds. This paper reported a simple method for producing hydrocarbons by liquefying biomass and upgrading liquefied products. Three phenolic...

  19. Acclimation of aerobic-activated sludge degrading benzene derivatives and co-metabolic degradation activities of trichloroethylene by benzene derivative-grown aerobic sludge.

    Science.gov (United States)

    Wang, Shizong; Yang, Qi; Bai, Zhiyong; Wang, Shidong; Wang, Yeyao; Nowak, Karolina M

    2015-01-01

    The acclimation of aerobic-activated sludge for degradation of benzene derivatives was investigated in batch experiments. Phenol, benzoic acid, toluene, aniline and chlorobenzene were concurrently added to five different bioreactors which contained the aerobic-activated sludge. After the acclimation process ended, the acclimated phenol-, benzoic acid-, toluene-, aniline- and chlorobenzene-grown aerobic-activated sludge were used to explore the co-metabolic degradation activities of trichloroethylene (TCE). Monod equation was employed to simulate the kinetics of co-metabolic degradation of TCE by benzene derivative-grown sludge. At the end of experiments, the mixed microbial communities grown under different conditions were identified. The results showed that the acclimation periods of microorganisms for different benzene derivatives varied. The maximum degradation rates of TCE for phenol-, benzoic acid-, toluene-, aniline- and chlorobenzene-grown aerobic sludge were 0.020, 0.017, 0.016, 0.0089 and 0.0047 mg g SS(-1) h(-1), respectively. The kinetic of TCE degradation in the absence of benzene derivative followed Monod equation well. Also, eight phyla were observed in the acclimated benzene derivative-grown aerobic sludge. Each of benzene derivative-grown aerobic sludge had different microbial community composition. This study can hopefully add new knowledge to the area of TCE co-metabolic by mixed microbial communities, and further the understanding on the function and applicability of aerobic-activated sludge.

  20. Flexible, durable proton energy degraders for the GE PETtrace

    DEFF Research Database (Denmark)

    Engle, J. W.; Gagnon, K.; Severin, Gregory

    2012-01-01

    In order to limit the formation of radioisotopic impurities during proton bombardments of solid targets, two methods of introducing degrader foils into the beam upstream of the target were tested. The first design uses a 445 μm thick fixed degrader machined from a single piece of aluminum. The se...

  1. A Kinetic Degradation Study of Curcumin in Its Free Form and Loaded in Polymeric Micelles

    NARCIS (Netherlands)

    Naksuriya, Ornchuma; van Steenbergen, Mies J.; Sastre Torano, Javier; Okonogi, Siriporn; Hennink, Wim E.

    Curcumin, a phenolic compound, possesses many pharmacological activities and is under clinical evaluation to treat different diseases. However, conflicting data about its stability have been reported. In this study, the kinetic degradation of curcumin from a natural curcuminoid mixture under various

  2. Sorption of a phenols mixture in aqueous solution with activated carbon; Sorcion de una mezcla de fenoles en solucion acuosa con carbon activado

    Energy Technology Data Exchange (ETDEWEB)

    Mejia M, D

    2004-07-01

    The constant population growth and the quick industrialization have caused severe damages to our natural aquifer resources for a great variety of organic and inorganic pollutants. Among these they are those phenol compounds that are highly toxic, resistant (to the degradation chemistry) and poorly biodegradable. The phenolic compounds is used in a great variety of industries, like it is the production of resins, nylon, plastifiers, anti-oxidants, oil additives, drugs, pesticides, colorants, explosives, disinfectants and others. The disseminated discharges or effluents coming from the industrial processes toward lakes and rivers are causing a growing adverse effect in the environment, as well as a risk for the health. Numerous studies exist on the phenols removal and phenols substituted for very varied techniques, among them they are the adsorption in activated carbon. This finishes it has been used successfully for the treatment of residual waters municipal and industrial and of drinking waters and it is considered as the best technique available to eliminate organic compounds not biodegradable and toxic present in aqueous solution (US EPA, 1991). However a little information exists on studies carried out in aqueous systems with more of a phenolic compound. The activated carbon is broadly used as adsorbent due to its superficial properties in the so much treatment of water as of aqueous wastes, adsorbent for the removal of organic pollutants. The main objective of this work is the adsorption of a aqueous mixture of phenol-4 chloro phenol of different concentrations in activated carbon of mineral origin of different meshes and to diminish with it their presence in water. The experiments were carried out for lots, in normal conditions of temperature and pressure. The experimental results show that the removal capacity depends so much of the superficial properties of the sorbent like of the physical properties and chemical of the sorbate. The isotherms were carried

  3. Removal of Phenol in Aqueous Solution Using Kaolin Mineral Clay

    International Nuclear Information System (INIS)

    Sayed, M.S.

    2008-01-01

    Kaolin clay were tested for phenol removal as toxic liquid waste from aqueous waste water. Several experimental conditions such as weight and particle size of clay were investigated to study batch kinetic techniques, also the ph and concentration of the phenol solution were carried out. The stability of the Langmuir adsorption model of the equilibrium data were studied for phenol sorbent clay system. Infrared spectra, thermogravimetric and differential thermal analysis techniques were used to characterize the behavior of kaolin clay and kaolin clay saturated with phenol. The results obtained showed that kaolin clay could be used successfully as an efficient sorbent material to remove phenol from aqueous solution

  4. Targeting proteins for degradation.

    Science.gov (United States)

    Schrader, Erin K; Harstad, Kristine G; Matouschek, Andreas

    2009-11-01

    Protein degradation plays a central role in many cellular functions. Misfolded and damaged proteins are removed from the cell to avoid toxicity. The concentrations of regulatory proteins are adjusted by degradation at the appropriate time. Both foreign and native proteins are digested into small peptides as part of the adaptive immune response. In eukaryotic cells, an ATP-dependent protease called the proteasome is responsible for much of this proteolysis. Proteins are targeted for proteasomal degradation by a two-part degron, which consists of a proteasome binding signal and a degradation initiation site. Here we describe how both components contribute to the specificity of degradation.

  5. Benzoic acid intermediates in the anaerobic biodegradation of phenols

    Energy Technology Data Exchange (ETDEWEB)

    Londry, K.L.; Fedorak, P.M

    1992-01-01

    Phenols have many environmental sources, including plants producing simple phenols to the complex phenolic polymers such as lignins. Phenols from industrial processes such as petroleum refining, coal conversion, and wood preservation are of greater concern because of their potential toxicity and recalcitrance. A review is presented describing the sources and types of phenols released into the environment, the role of various electron acceptors in environmental situations, and the common occurrence of benzoic acid intermediates in the biotransformations of lignin-derived aromatic compounds. The anaerobic metabolism of phenol and the three cresol isomers is addressed in detail to illustrate that the formation of benzoic acid is a common feature in phenol biodegradation. Finally, the known pathways for benzoic acid metabolism under anaerobic conditions are reviewed. 101 refs., 4 figs., 2 tabs.

  6. Introducing Relativity: Less May Be More

    Science.gov (United States)

    Ogborn, Jon

    2005-01-01

    This article shows how relativity can be introduced in four stages, each building on those before it, but the teacher can choose to stop after whichever stage he/she believes the pupils are capable of tackling.

  7. pcaH, a molecular marker for estimating the diversity of the protocatechuate-degrading bacterial community in the soil environment

    DEFF Research Database (Denmark)

    El Azhari, Najoi

    2007-01-01

    Microorganisms degrading phenolic compounds play an important role in soil carbon cycling as well as in pesticide degradation. The pcaH gene encoding a key ring-cleaving enzyme of the β-ketoadipate pathway was selected as a functional marker. Using a degenerate primer pair, pcaH fragments were cl...

  8. Traits and Resource Use of Co-Occurring Introduced and Native Trees in a Tropical Novel Forest

    Science.gov (United States)

    Jéssica Fonseca da Silva; Ernesto Medina; Ariel Lugo

    2017-01-01

    Novel forests are naturally regenerating forests that have established on degraded lands and have a species composition strongly influenced by introduced species. We studied ecophysiological traits of an introduced species (Castilla elastica Sessé) and several native species growing side by side in novel forests dominated by C. elastica ...

  9. Adsorption of phenolic compounds from aqueous solutions by aminated hypercrosslinked polymers.

    Science.gov (United States)

    Jiang, Zhen-mao; Li, Ai-min; Cai, Jian-guo; Wang, Chun; Zhang, Quan-xin

    2007-01-01

    Two novel polymers (NJ-1 and NJ-2) were synthesized by chemically modified a hypercrosslinked polymer NJ-0 with dimethylamine and trimethylamine, respectively. The comparison of the adsorption properties of the three polymers toward phenol, resorcin and phloroglucin was made. The study focused on the static equilibrium adsorption behaviors and the adsorption thermodynamics. Freundlich equation was found to fit the adsorption results well. The effect of amino groups introduced onto the surface of the resin and the structure of phenolic compounds on the adsorption were also studied. The hydrogen-bonding interaction and electrostatic interaction could happen between the amino groups and the adsorbates. The adsorption impetus increased as quantity of hydroxyl groups increased, but the adsorption capacity decreased due to the drop of the matching degree of the aperture of resins and the diameter of adsorbate molecules.

  10. Phenolics from Kalanchoe marmorata Baker, Family Crassulaceae

    Directory of Open Access Journals (Sweden)

    Abdel Nasser Badawy Singab

    2011-06-01

    Full Text Available In search of plants rich in phenolics in Egypt, Kalanchoe marmorata Baker was subjected to phytochemical study. The preliminary phytochemical screening revealed its richness in phenolics. Fractionation of the lyophilized aqueous extract of the leaves of K. marmorata by different organic solvents successively resulted in the isolation and purification of five compounds from the ethyl acetate soluble fraction. These compounds namely; E1 isorhamnetin-3-O-α-l-1C4-rhamnopyranoside; E2 quercitin; E3 4′-methoxy-myricetin-3-O-α-l-1C4-rhamnopyranoside; E4 Quercitin-3-O-β-d-4C1-glucopyranoside and E5 protocatechuic-4′-O-β-d-4C1-glucopyranoside, were identified by analysis of their spectral data including 1H NMR and 13C NMR.

  11. Bioactivity of Olive Oil Phenols in Neuroprotection

    Science.gov (United States)

    Angeloni, Cristina; Barbalace, Maria Cristina

    2017-01-01

    Neurological disorders such as stroke, Alzheimer’s and Parkinson’s diseases are associated with high morbidity and mortality, and few or no effective options are available for their treatment. These disorders share common pathological characteristics like the induction of oxidative stress, abnormal protein aggregation, perturbed Ca2+ homeostasis, excitotoxicity, inflammation and apoptosis. A large body of evidence supports the beneficial effects of the Mediterranean diet in preventing neurodegeneration. As the Mediterranean diet is characterized by a high consumption of extra-virgin olive oil it has been hypothesized that olive oil, and in particular its phenols, could be responsible for the beneficial effect of the Mediterranean diet. This review provides an updated vision of the beneficial properties of olive oil and olive oil phenols in preventing/counteracting both acute and chronic neurodegenerative diseases. PMID:29068387

  12. Studies on the physiology of microbial degradation of pentachlorophenol

    Energy Technology Data Exchange (ETDEWEB)

    Valo, R.; Apajalahti, J.; Salkinoja-Salonen, M.

    1985-03-01

    The requirements and conditions for pentachlorophenol (PCP) biodegradation by a mixed bacterial culture was studied. The effects of oxygen, nutrients, additional carbon sources, pH and temperature are described. Up to 90% of PCP was degraded into CO/sub 2/ and inorganic chloride in 1 week at an input concentration of <600 ..mu..M. Degradation continued when pO/sub 2/ was lowered to 0.0002 atm but ceased when pO/sub 2/ was further decreased to 0.00002 atm. Supplementary carbon sources, such as phenol, hydroxybenzoic acids or complex nutrients did not affect the biodegradation, but the presence of ammonium salts enhanced the rate of PCP degradation without affecting the yield of CO/sub 2/. The degrading organisms were shown to be procaryotic mesophiles; no degradation was shown at temperatures below +8/sup 0/ and above +50/sup 0/C. The optimum pH for degradation was from 6.4 to 7.2 and at higher pH value (8.4) degradation was inhibited more than at lower pH (5.6).

  13. Effect of metal chlorides on thermal degradation of (waste) polycarbonate.

    Science.gov (United States)

    Chiu, Shwu-Jer; Chen, Shi-Hau; Tsai, Chou-Tso

    2006-01-01

    In this study, we investigated how to treat (waste) polycarbonate efficiently to reduce its degraded residue. The study was carried out in an isothermal reactor under continuous nitrogen flow at atmospheric pressure to pyrolyze polycarbonate (PC) alone and in the presence of metal chloride. Some metal chlorides were shown to be catalytic active for the degradation of PC at 400 degrees C, which increased degradation conversion from 8.5% to more than 58.3%. Among those active metal chlorides, ZnCl2 and SnCl2 can produce higher liquid product yields. Effects such as particle size of PC, temperature, the weight ratio of metal chloride/PC, and degradation time on the degradation conversion of PC without and with these two most active metal chlorides were studied. Results of the liquid product analysis by GC/MS demonstrated the product composition of PC degradation over the metal chlorides is much simpler than that of degradation alone. The main liquid product is phenol, p-isopropylphenol, diphenyl carbonate, and bisphenol A for all cases.

  14. Discoloration of polymers by phenolic antioxidants

    Czech Academy of Sciences Publication Activity Database

    Pospíšil, Jan; Habicher, W. D.; Pilař, Jan; Nešpůrek, Stanislav; Kuthan, J.; Piringer, G. O.; Zweifel, H.

    2002-01-01

    Roč. 77, č. 3 (2002), s. 531-538 ISSN 0141-3910 R&D Projects: GA ČR GA202/01/0518; GA ČR GA203/02/1243 Institutional research plan: CEZ:AV0Z4050913 Keywords : polymer discoloration * phenolic antioxidant * antioxidant transformation Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.145, year: 2002

  15. Flavonoid, hesperidine, total phenolic contents and antioxidant ...

    African Journals Online (AJOL)

    ONOS

    2010-01-11

    Jan 11, 2010 ... distilled water) and allowed to stand at 22ºC for 5 min. Then, 0.75. mL of sodium carbonate (60 g/L) ... was taken in a test tube and incubated at 30°C in water bath for 10 min. Then, absorbance was taken at 0 .... have reported high DPPH scavenging activity of lemon compared to orange. The high phenolic ...

  16. Monitoring of phenol photodegradation by ultraviolet spectroscopy

    Science.gov (United States)

    Roig, B.; Gonzalez, C.; Thomas, O.

    2003-01-01

    Advanced oxidation processes (AOPs) have been developed as an emerging technology for hazardous organic treatment in industrial wastewater. In this paper, the contribution of ultraviolet (UV) spectroscopy to follow phenol photodegradation was studied in a laboratory photochemical reactor equipped with a low pressure mercury lamp. It has been observed that a multicomponent approach is efficient for the evolution estimation of the initial product or intermediate compounds formed during the photodegradation.

  17. Spice phenolics inhibit human PMNL 5-lipoxygenase.

    Science.gov (United States)

    Prasad, N Satya; Raghavendra, R; Lokesh, B R; Naidu, K Akhilender

    2004-06-01

    A wide variety of phenolic compounds and flavonoids present in spices possess potent antioxidant, antimutagenic and anticarcinogenic activities. We examined whether 5-lipoxygenase (5-LO), the key enzyme involved in biosynthesis of leukotrienes is a possible target for the spices. Effect of aqueous extracts of turmeric, cloves, pepper, chili, cinnamon, onion and also their respective active principles viz., curcumin, eugenol, piperine, capsaicin, cinnamaldehyde, quercetin, and allyl sulfide were tested on human PMNL 5-LO activity by spectrophotomeric and HPLC methods. The formation of 5-LO product 5-HETE was significantly inhibited in a concentration-dependent manner with IC(50) values of 0.122-1.44 mg for aqueous extracts of spices and 25-83 microM for active principles, respectively. The order of inhibitory activity was of quercetin>eugenol>curcumin>cinnamaldehyde>piperine>capsaicin>allyl sulfide. Quercetin, eugenol and curcumin with one or more phenolic ring and methoxy groups in their structure showed high inhibitory effect, while the non-phenolic spice principle allyl sulfide showed least inhibitory effect on 5-LO. The inhibitory effect of quercetin, curcumin and eugenol was similar to that of synthetic 5-LO inhibitors-phenidone and NDGA. Moreover, the inhibitory potency of aqueous extracts of spice correlated with the active principles of their respective spices. The synergistic or antagonistic effect of mixtures of spice active principles and spice extracts were investigated and all the combinations of spice active principles/extracts exerted synergistic effect in inhibiting 5-LO activity. These findings clearly suggest that phenolic compounds present in spices might have physiological role in modulating 5-LO pathway.

  18. Detection of Total Phenol in Green and Black Teas by Flow Injection System and Unmodified Screen Printed Electrode

    Directory of Open Access Journals (Sweden)

    Ivanildo Luiz de Mattos

    2010-01-01

    Full Text Available A flow injection system using an unmodified gold screen-printed electrode was employed for total phenol determination in black and green teas. In order to avoid passivation of the electrode surface due to the redox reaction, preoxidation of the sample was realized by hexacyanoferrate(III followed by addition of an EDTA solution. The complex formed in the presence of EDTA minimizes or avoids polymerization of the oxidized phenols. The previously filtered tea sample and hexacyanoferrate(III reagent were introduced simultaneously into two-carrier streams producing two reproducible zones. At confluence point, the pre-oxidation of the phenolic compounds occurs while this zone flows through the coiled reactor and receives the EDTA solution before phenol detection. The consumption of ferricyanide was monitorized at 360 mV versus Ag/AgCl and reflected the total amount of phenolic compounds present in the sample. Results were reported as gallic acid equivalents (GAEs. The proposed system is robust, versatile, environmentally-friendly (since the reactive is used only in the presence of the sample, and allows the analysis of about 35–40 samples per hour with detection limit = 1 mg/L without the necessity for surface cleaning after each measurement. Precise results are in agreement with those obtained by the Folin-Ciocalteu method.

  19. Detection of Total Phenol in Green and Black Teas by Flow Injection System and Unmodified Screen Printed Electrode

    Science.gov (United States)

    de Mattos, Ivanildo Luiz; Zagal, José Heraclito

    2010-01-01

    A flow injection system using an unmodified gold screen-printed electrode was employed for total phenol determination in black and green teas. In order to avoid passivation of the electrode surface due to the redox reaction, preoxidation of the sample was realized by hexacyanoferrate(III) followed by addition of an EDTA solution. The complex formed in the presence of EDTA minimizes or avoids polymerization of the oxidized phenols. The previously filtered tea sample and hexacyanoferrate(III) reagent were introduced simultaneously into two-carrier streams producing two reproducible zones. At confluence point, the pre-oxidation of the phenolic compounds occurs while this zone flows through the coiled reactor and receives the EDTA solution before phenol detection. The consumption of ferricyanide was monitorized at 360 mV versus Ag/AgCl and reflected the total amount of phenolic compounds present in the sample. Results were reported as gallic acid equivalents (GAEs). The proposed system is robust, versatile, environmentally-friendly (since the reactive is used only in the presence of the sample), and allows the analysis of about 35–40 samples per hour with detection limit = 1 mg/L without the necessity for surface cleaning after each measurement. Precise results are in agreement with those obtained by the Folin-Ciocalteu method. PMID:21461407

  20. ABTS assay of phenol oxidase activity in soil.

    Science.gov (United States)

    Floch, Carine; Alarcon-Gutiérrez, Enrique; Criquet, Stéven

    2007-12-01

    Phenol oxidases (PO) are involved in degradation of many recalcitrant aromatic compounds and may be sensitive to some pollutants. Hence, their activities may be a useful indicator for evaluating soil quality and health. To this end, the aim of this study was to develop a simple method to assay PO activity directly in bulk samples by spectrophotometric test using 2,2'-azinobis-(-3 ethylbenzothiazoline-6-sulfononic acid) diammonium salt (ABTS) as the substrate. Three Mediterranean soils were used as models. For each soil, we studied the kinetic parameters and the effects of certain factors (i.e. amount of soil, pH, temperature, incubation time and substrate concentration) in order to determine the optimum conditions for the ABTS assay. Results showed that PO attain their optimum activities when incubating 0.1 g of soil at 30 degrees C for 5 min with 10 ml of a Modified Universal Buffer (MUB) at pH 2 and 200 microl of a 0.1 M ABTS solution.

  1. Subcritical water extraction of flavoring and phenolic compounds from cinnamon bark (Cinnamomum zeylanicum).

    Science.gov (United States)

    Khuwijitjaru, Pramote; Sayputikasikorn, Nucha; Samuhasaneetoo, Suched; Penroj, Parinda; Siriwongwilaichat, Prasong; Adachi, Shuji

    2012-01-01

    Cinnamon bark (Cinnamomum zeylanicum) powder was treated with subcritical water at 150 and 200°C in a semi-continuous system at a constant flow rate (3 mL/min) and pressure (6 MPa). Major flavoring compounds, i.e., cinnamaldehyde, cinnamic acid, cinnamyl alcohol and coumarin, were extracted at lower recoveries than the extraction using methanol, suggesting that degradation of these components might occur during the subcritical water treatment. Caffeic, ferulic, p-coumaric, protocatechuic and vanillic acids were identified from the subcritical water treatment. Extraction using subcritical water was more effective to obtain these acids than methanol (50% v/v) in both number of components and recovery, especially at 200°C. Subcritical water treatment at 200°C also resulted in a higher total phenolic content and DPPH radical scavenging activity than the methanol extraction. The DPPH radical scavenging activity and total phenolic content linearly correlated but the results suggested that the extraction at 200°C might result in other products that possessed a free radical scavenging activity other than the phenolic compounds.

  2. Consequences of plant phenolic compounds for productivity and health of ruminants.

    Science.gov (United States)

    Waghorn, Garry C; McNabb, Warren C

    2003-05-01

    Plant phenolic compounds are diverse in structure but are characterised by hydroxylated aromatic rings (e.g. flavan-3-ols). They are categorised as secondary metabolites, and their function in plants is often poorly understood. Many plant phenolic compounds are polymerised into larger molecules such as the proanthocyanidins (PA; condensed tannins) and lignins. Only the lignins, PA, oestrogenic compounds and hydrolysable tannins will be considered here. Lignins slow the physical and microbial degradation of ingested feed, because of resilient covalent bonding with hemicellulose and cellulose, rather than any direct effects on the rumen per se. The PA are prevalent in browse and are expressed in the foliage of some legumes (e.g. Lotus spp.), but rarely in grasses. They reduce the nutritive value of poor-quality diets, but can also have substantial benefits for ruminant productivity and health when improved temperate forages are fed. Beneficial effects are dependent on the chemical and physical structure, and concentration of the PA in the diet, but they have been shown to improve live-weight gain, milk yield and protein concentration, and ovulation rate. They prevent bloat in cattle, reduce gastrointestinal nematode numbers, flystrike and CH4 production. Some phenolic compounds (e.g. coumestans) cause temporary infertility, whilst those produced by Fusarium fungi found in pasture, silage or stored grains can cause permanent infertility. The HT may be toxic because products of their metabolism can cause liver damage and other metabolic disorders.

  3. Inhibitory effects of furan derivatives and phenolic compounds on dark hydrogen fermentation.

    Science.gov (United States)

    Lin, Richen; Cheng, Jun; Ding, Lingkan; Song, Wenlu; Zhou, Junhu; Cen, Kefa

    2015-11-01

    The inhibitory effects of furan derivatives [i.e. furfural and 5-hydroxymethylfurfural (5-HMF)] and phenolic compounds (i.e. vanillin and syringaldehyde) on dark hydrogen fermentation from glucose were comparatively evaluated. Phenolic compounds exhibited stronger inhibition on hydrogen production and glucose consumption than furan derivatives under the same 15mM concentration. Furan derivatives were completely degraded after 72h fermentation, while over 55% of phenolic compounds remained unconverted after 108h fermentation. The inhibition coefficients of vanillin (14.05) and syringaldehyde (11.21) were higher than those of 5-HMF (4.35) and furfural (0.64). Vanillin exhibited the maximum decrease of hydrogen yield (17%). The consumed reducing power by inhibitors reduction from R-CHO to RCH2OH was a possible reason contributed to the decreased hydrogen yield. Vanillin exhibited the maximum delay of peak times of hydrogen production rate and glucose consumption. Soluble metabolites and carbon conversion efficiency decreased with inhibitors addition, which were consistent with hydrogen production. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Effects of plant antimicrobial phenolic compounds on virulence of the genus Pectobacterium.

    Science.gov (United States)

    Joshi, Janak Raj; Burdman, Saul; Lipsky, Alexander; Yedidia, Iris

    2015-01-01

    Pectobacterium spp. are among the most devastating necrotrophs, attacking more than 50% of angiosperm plant orders. Their virulence strategy is based mainly on the secretion of exoenzymes that degrade the cell walls of their hosts, providing nutrients to the bacteria, but conversely, exposing the bacteria to plant defense compounds. In the present study, we screened plant-derived antimicrobial compounds, mainly phenolic acids and polyphenols, for their ability to affect virulence determinants including motility, biofilm formation and extracellular enzyme activities of different Pectobacteria: Pectobacterium carotovorum, P. brasiliensis, P. atrosepticum and P. aroidearum. In addition, virulence assays were performed on three different plant hosts following exposure of the bacteria to selected phenolic compounds. These experiments showed that cinnamic, coumaric, syringic and salicylic acids and catechol can considerably reduce disease severity, ranging from 20 to 100%. The reduced disease severity was not only the result of reduced bacterial growth, but also of a direct effect of the compounds on important bacterial virulence determinants, including pectolytic and proteolytic exoenzyme activities, that were reduced by 50-100%. This is the first report revealing a direct effect of phenolic compounds on virulence factors in a wide range of Pectobacterium strains. Copyright © 2015 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  5. Influence of taro (Colocasia esculenta L. Shott) growth conditions on the phenolic composition and biological properties.

    Science.gov (United States)

    Gonçalves, Rui F; Silva, Artur M S; Silva, Ana Margarida; Valentão, Patrícia; Ferreres, Federico; Gil-Izquierdo, Angel; Silva, João B; Santos, Delfim; Andrade, Paula B

    2013-12-15

    Colocasia esculenta (L.) Shott, commonly known as taro, is an essential food for millions of people. The leaves are consumed in sauces, purees, stews, and soups, being also used in wound healing treatment. Nowadays, the consumers' demand for bioactive compounds from the diet led to the development of new agricultural strategies for the production of health-promoting constituents in vegetables. In this work, two strategies (variety choice and irrigation conditions) were considered in the cultivation of C. esculenta. The effect on the phenolic composition of the leaves was evaluated. Furthermore, a correlation between the biological activity of the different varieties and their chemical composition was established. Qualitative and quantitative differences in the phenolic composition were observed between varieties; furthermore, the irrigation conditions also influenced the composition. C. esculenta varieties were able to scavenge several oxidant species and to inhibit hyaluronidase, but data suggest that metabolites other than phenolics are involved. The results show that cultivation strategies can effectively modulate the accumulation of these types of bioactive compounds. Furthermore C. esculenta wound healing potential can be attributed, at least in part, to the protection of the wound site against oxidative/nitrosative damage and prevention of hyaluronic acid degradation. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. A strategy for introducing hydrogen into transportation

    International Nuclear Information System (INIS)

    Farrell, A.E.; Keith, D.W.; Corbett, J.J.

    2003-01-01

    Considerable effort is being expended on research and demonstration projects aimed at introducing hydrogen into the transportation sector as a fuel, generally motivated by concerns about carbon dioxide emissions and petroleum imports (or scarcity). In this paper we focus on one aspect of strategy for introducing hydrogen--the choice of transportation mode. Our analysis suggests that cost of introducing hydrogen can be reduced by selecting a mode that uses a small number of relatively large vehicles that are operated by professional crews along a limited number of point-to-point routes or within a small geographic area. In addition, technological innovation in vehicle design will take place most quickly in modes where individual vehicles are produced to order and each receives significant engineering attention (not those manufactured in vast quantities on assembly lines). The immediate environmental benefits of introducing hydrogen fuel will occur in modes that have relatively less stringent pollution regulations applied to them. These insights, suggest that heavy-duty freight modes would be a less costly way to introduce hydrogen as a transportation fuel and a more effective way to advance hydrogen-related technologies so that they could subsequently be used more widely in light-duty vehicles

  7. Estimate of consumption of phenolic compounds by Brazilian population

    Directory of Open Access Journals (Sweden)

    Vanesa Gesser Corrêa

    2015-04-01

    Full Text Available OBJECTIVE: Estimate the intake of phenolic compounds by the Brazilian population. METHODS: To estimate the average per capita food consumption, micro data from the National Dietary Survey and from the Household Budget Survey from 2008 to 2009 was analyzed. The phenolic content in food was estimated from the base of Phenol-Explorer. It was chosen according to compatibility and variety of food items and usual method of preparation. RESULTS: The Brazilian population consumed, on average, 460.15 mg/day of total phenolic compounds, derived mainly from beverages (48.9%, especially coffee and legumes (19.5%. Since this analysis of classes of phenolics it was possible to observe an intake of 314 mg/day of phenolic acids, 138.92 mg/day of flavonoids and 7.16 mg/ day of other kinds of phenolics. Regarding the variables studied this present study shows that those men who live in the countryside and in the northeastern region of the country had a higher consumption of phenolic compounds. Besides, consumption was higher by adults and the elderly, the medium income classes, the population with incomplete and complete primary education and those with adequate nutrition and also overweight status. CONCLUSION: The intake of phenolic compounds can be considered low, especially where consumption of fruit and vegetables is insufficient. We can conclude that coffee and black beans were the best contributors to phenolic intake.

  8. Thermomechanical analyses of phenolic foam reinforced with glass fiber mat

    International Nuclear Information System (INIS)

    Zhou, Jintang; Yao, Zhengjun; Chen, Yongxin; Wei, Dongbo; Wu, Yibing

    2013-01-01

    Highlights: • Over 10% glass fiber was used to reinforce phenolic foam in the shape of glass fiber mat. • Nucleating agents were used together with glass fiber mat and improved tensile strength of phenolic foam by 215.6%. • Nucleating agents lead to a smaller bubble size of phenolic foam. • The glass transition temperature of phenolic foam remained unchanged during the reinforcement. - Abstract: In this paper, thermomechanical analysis (TMA) and dynamic mechanical analysis were employed to study the properties of phenolic foam reinforced with glass fiber mat. Unreinforced phenolic foam was taken as the control sample. Mechanical tests and scanning electron microscopy were performed to confirm the results of TMA. The results show that glass fiber mat reinforcement improves the mechanical performance of phenolic foam, and nucleating agents improve it further. Phenolic foam reinforced with glass fiber mat has a smaller thermal expansion coefficient compared with unreinforced foam. The storage modulus of the reinforced phenolic foam is also higher than that in unreinforced foam, whereas the loss modulus of the former is lower than that of the latter. The glass transition temperature of the phenolic foam matrix remains unchanged during the reinforcement

  9. Synthesis of a boron modified phenolic resin

    Directory of Open Access Journals (Sweden)

    Aparecida M. Kawamoto

    2010-08-01

    Full Text Available Phenolic resin has long been used as matrix for composites mainly because of its flame retardant behavior and high char yield after pyrolysis, which results in a self supporting structure. The addition of ceramic powders, such as SiC and B4C, as fillers to the phenolic resin, results in better thermo-oxidative stability, but as drawbacks, it has poor homogeneity, adhesion and processing difficulties during molding of the composites. The addition of single elements, such as boron, silicon and phosphorus in the main backbone of the thermo-set resin is a new strategy to obtain special high performance resins, which results in higher mechanical properties, avoiding the drawbacks of simply adding fillers, which results in enhanced thermo-oxidative stability compared to conventional phenol-formaldehyde resins. Therefore, the product can have several applications, including the use as ablative thermal protection for thermo-structural composites. This work describes the preparation of a boron-modified phenolic resin (BPR using salicyl alcohol and boric acid. The reaction was performed in refluxing toluene for a period of four hours, which produced a very high viscosity amber resin in 90% yield.The final structure of the compound, the boric acid double, substituted at the hydroxyl group of the aromatic ring, was determined with the help of the Infrared Spectroscopy, ¹H-NMR, TGA-DSC and boron elemental analysis. The absorption band of the group B-O at 1349 cm ˉ¹ can be visualized at the FT-IR spectrum. ¹H-NMR spectra showed peaks at 4.97-5.04 ppm and 3.60-3.90 ppm assigned to belong to CH2OH groups from the alcohol. The elemental analysis was also performed for boron determination.The product has also been tested in carbon and silicon fibers composite for the use in thermal structure. The results of the tests showed composites with superior mechanical properties when compared with the conventional phenolic resin.

  10. Properties and processing characteristics of low density carbon cloth phenolic composites

    Science.gov (United States)

    Wang, C. Jeff

    1993-01-01

    Ply-lift and pocketing are two critical anomalies of carbon cloth phenolic composites (CCPC) in rocket nozzle applications. Ply lift occurs at low temperatures when the A/P and in-plane permeabilities of the composite materials are still very low and in-plane porous paths are blocked. Pocketing occurs at elevated temperatures when in-plane permeability is reduced by the A/P compressive stress. The thermostructural response of CCPC in a rapid heating environment involves simultaneous heat, mass, and momentum transfer along with the degradation of phenolic resin in a multiphase system with temperature- and time-dependent material properties as well as dynamic processing conditions. Three temperature regions represent the consequent chemical reactions, material transformations, and property transitions, and provide a quick qualitative method for characterizing the thermostructural behavior of a CCPC. In order to optimize the FM5939 LDCCP (low density carbon cloth phenolic) for the nozzle performance required in the Advanced Solid Rocket Motor (ASRM) program, a fundamental study on LDCCP materials was conducted. The cured composite has a density of 1.0 +/- 0.5 gm/cc which includes 10 to 25 percent void volume. The weight percent of carbon microballoon is low (7-15 percent). However, they account for approximately one third of the volume and historically their percentages have not been controlled very tightly. In addition, the composite properties show no correlation with microballoon weight percent or fiber properties (e.g. fiber density or fiber moisture adsorption capacity). Test results concerning the ply-lift anomaly in the MNASA motor firings were: (1) Steeper ply angle (shorter path lenght) designs minimized/eliminated by lifting, (2) material with higher void volume ply lifted less frequently, (3) materials with high (greater than 9 percent) microballoon content had a higher rate of ply lifting, and (4) LDCCP materials failed at microballoon-resin interfaces

  11. Degradation of Synthetic Dyes by Laccases – A Mini-Review

    Directory of Open Access Journals (Sweden)

    Legerská Barbora

    2016-06-01

    Full Text Available Laccases provide a promising future as a tool to be used in the field of biodegradation of synthetic dyes with different chemical structures. These enzymes are able to oxidize a wide range of phenolic substrates without the presence of additional co-factors. Laccases have been confirmed for their potential of synthetic dye degradation from wastewater and degradation products of these enzymatic reactions become less toxic than selected dyes. This study discusses the potential of laccase enzymes as agents for laccase-catalyzed degradation in terms of biodegradation efficiency of synthetic dyes, specifically: azo dyes, triphenylmethane, indigo and anthraquinone dyes. Review also summarizes the laccase-catalyzed degradation mechanisms of the selected synthetic dyes, as well as the degradation products and the toxicity of the dyes and their degradation products.

  12. Photocatalytic Based Degradation Processes of Lignin Derivatives

    Directory of Open Access Journals (Sweden)

    Colin Awungacha Lekelefac

    2015-01-01

    Full Text Available Photocatalysis, belonging to the advanced oxidation processes (AOPs, is a potential new transformation technology for lignin derivatives to value added products (e.g., phenol, benzene, toluene, and xylene. Moreover, lignin represents the only viable source to produce aromatic compounds as fossil fuel alternative. This review covers recent advancement made in the photochemical transformation of industrial lignins. It starts with the photochemical reaction principle followed by results obtained by varying process parameters. In this context, influences of photocatalysts, metal ions, additives, lignin concentration, and illumination intensity and the influence of pH are presented and discussed. Furthermore, an overview is given on several used process analytical methods describing the results obtained from the degradation of lignin derivatives. Finally, a promising concept by coupling photocatalysis with a consecutive biocatalytic process was briefly reviewed.

  13. Contribution of Polyphenol Oxidation, Chlorophyll and Vitamin C Degradation to the Blackening of Piper nigrum L.

    Science.gov (United States)

    Gu, Fenglin; Huang, Feifei; Wu, Guiping; Zhu, Hongying

    2018-02-09

    Black pepper ( Piper nigrum L.) is the most widely used spice in the world. Blackening is considered to be beneficial and important in the processing of black pepper because it contributes to its color and flavor. The purpose of this paper is to investigate polyphenol oxidation as well as the chlorophyll and vitamin C (VC) degradation in the blackening of Piper nigrum L. Black pepper was produced by four methods, and changes in polyphenols, chlorophyll and VC were studied by high performance liquid chromatography (HPLC) and ultraviolet-visible and visible (UV-Vis) spectrophotometry. The results show that polyphenol oxidase activity significantly decreased during the preparation of black pepper, and the concentrations of phenolic compounds, VC, and chlorophyll a and b also significantly decreased. Polyphenol oxidation and chlorophyll and VC degradation contribute to the blackening. A crude extract of phenolic compounds from black pepper was prepared by the system solvent method. The greater the polarity of the extraction solvent, the higher the extraction rates of the phenolic compounds and the total phenol content. Pepper phenolic compounds were analyzed by HPLC analysis.

  14. Contribution of Polyphenol Oxidation, Chlorophyll and Vitamin C Degradation to the Blackening of Piper nigrum L.

    Directory of Open Access Journals (Sweden)

    Fenglin Gu

    2018-02-01

    Full Text Available Black pepper (Piper nigrum L. is the most widely used spice in the world. Blackening is considered to be beneficial and important in the processing of black pepper because it contributes to its color and flavor. The purpose of this paper is to investigate polyphenol oxidation as well as the chlorophyll and vitamin C (VC degradation in the blackening of Piper nigrum L. Black pepper was produced by four methods, and changes in polyphenols, chlorophyll and VC were studied by high performance liquid chromatography (HPLC and ultraviolet-visible and visible (UV-Vis spectrophotometry. The results show that polyphenol oxidase activity significantly decreased during the preparation of black pepper, and the concentrations of phenolic compounds, VC, and chlorophyll a and b also significantly decreased. Polyphenol oxidation and chlorophyll and VC degradation contribute to the blackening. A crude extract of phenolic compounds from black pepper was prepared by the system solvent method. The greater the polarity of the extraction solvent, the higher the extraction rates of the phenolic compounds and the total phenol content. Pepper phenolic compounds were analyzed by HPLC analysis.

  15. Newly introduced sample preparation techniques: towards miniaturization.

    Science.gov (United States)

    Costa, Rosaria

    2014-01-01

    Sampling and sample preparation are of crucial importance in an analytical procedure, representing quite often a source of errors. The technique chosen for the isolation of analytes greatly affects the success of a chemical determination. On the other hand, growing concerns about environmental and human safety, along with the introduction of international regulations for quality control, have moved the interest of scientists towards specific needs. Newly introduced sample preparation techniques are challenged to meet new criteria: (i) miniaturization, (ii) higher sensitivity and selectivity, and (iii) automation. In this survey, the most recent techniques introduced in the field of sample preparation will be described and discussed, along with many examples of applications.

  16. Introducing particle physics a graphic guide

    CERN Document Server

    AUTHOR|(CDS)2071677

    2013-01-01

    What really happens at the most fundamental levels of nature? Introducing Particle Physics explores the very frontiers of our knowledge, even showing how particle physicists are now using theory and experiment to probe our very concept of what is real. From the earliest history of the atomic theory through to supersymmetry, micro-black holes, dark matter, the Higgs boson, and the possibly mythical graviton, practising physicist and CERN contributor Tom Whyntie gives us a mind-expanding tour of cutting-edge science. Featuring brilliant illustrations from Oliver Pugh, Introducing Particle Physics is a unique tour through the most astonishing and challenging science being undertaken today.

  17. Roles of small laccases from Streptomyces in lignin degradation.

    Science.gov (United States)

    Majumdar, Sudipta; Lukk, Tiit; Solbiati, Jose O; Bauer, Stefan; Nair, Satish K; Cronan, John E; Gerlt, John A

    2014-06-24

    Laccases (EC 1.10.3.2) are multicopper oxidases that can oxidize a range of substrates, including phenols, aromatic amines, and nonphenolic substrates. To investigate the involvement of the small Streptomyces laccases in lignin degradation, we generated acid-precipitable polymeric lignin obtained in the presence of wild-type Streptomyces coelicolor A3(2) (SCWT) and its laccase-less mutant (SCΔLAC) in the presence of Miscanthus x giganteus lignocellulose. The results showed that strain SCΔLAC was inefficient in degrading lignin compared to strain SCWT, thereby supporting the importance of laccase for lignin degradation by S. coelicolor A3(2). We also studied the lignin degradation activity of laccases from S. coelicolor A3(2), Streptomyces lividans TK24, Streptomyces viridosporus T7A, and Amycolatopsis sp. 75iv2 using both lignin model compounds and ethanosolv lignin. All four laccases degraded a phenolic model compound (LM-OH) but were able to oxidize a nonphenolic model compound only in the presence of redox mediators. Their activities are highest at pH 8.0 with a low krel/Kapp for LM-OH, suggesting that the enzymes’ natural substrates must be different in shape or chemical nature. Crystal structures of the laccases from S. viridosporus T7A (SVLAC) and Amycolatopsis sp. 75iv2 were determined both with and without bound substrate. This is the first report of a crystal structure for any laccase bound to a nonphenolic β-O-4 lignin model compound. An additional zinc metal binding site in SVLAC was also identified. The ability to oxidize and/or rearrange ethanosolv lignin provides further evidence of the utility of laccase activity for lignin degradation and/or modification.

  18. Synthesis and Characterization of Bio-Oil Phenol Formaldehyde Resin Used to Fabricate Phenolic Based Materials

    OpenAIRE

    Cui, Yong; Hou, Xiaopeng; Wang, Wenliang; Chang, Jianmin

    2017-01-01

    In this study, bio-oil from the fast pyrolysis of renewable biomass was used as the raw material to synthesize bio-oil phenol formaldehyde (BPF) resin—a desirable resin for fabricating phenolic-based material. During the synthesis process, paraformaldehyde was used to achieve the requirement of high solid content and low viscosity. The properties of BPF resins were tested. Results indicated that BPF resin with the bio-oil addition of 20% had good performance on oxygen index and bending streng...

  19. A Laboratory Exercise To Understand the Importance of Enzyme Technology in the Fruit-Processing Industry: Viscosity Decrease and Phenols Release from Apple Mash

    DEFF Research Database (Denmark)

    Pinelo, Manuel; Nielsen, Michael Krogsgaard; Meyer, Anne S.

    2011-01-01

    In a 4-h laboratory exercise, students accomplish a series of enzymatic macerations of apple mash, assess the viscosity of the mash during the maceration, extract the juice by centrifugation, and measure the levels of antioxidant phenols extracted into the juice after different enzyme treatments....... The exercise shows the impact of enzyme-catalyzed plant cell-wall degradation on the viscosity of apple fruit mash and on the extraction of antioxidant phenols into experimentally prepared apple juice. The exercise also demonstrates that pectinolytic and cellulolytic enzymes have different effects...

  20. The hydrogen bond strength of the phenol-phenolate anionic complex: a computational and photoelectron spectroscopic study.

    Science.gov (United States)

    Buytendyk, Allyson M; Graham, Jacob D; Collins, Kim D; Bowen, Kit H; Wu, Chia-Hua; Wu, Judy I

    2015-10-14

    The phenol-phenolate anionic complex was studied in vacuo by negative ion photoelectron spectroscopy using 193 nm photons and by density functional theory (DFT) computations at the ωB97XD/6-311+G(2d,p) level. We characterize the phenol-phenolate anionic complex as a proton-coupled phenolate pair, i.e., as a low-barrier hydrogen bond system. Since the phenol-phenolate anionic complex was studied in the gas phase, its measured hydrogen bond strength is its maximal ionic hydrogen bond strength. The D(PhO(-)···HOPh) interaction energy (26-30 kcal mol(-1)), i.e., the hydrogen bond strength in the PhO(-)···HOPh complex, is quite substantial. Block-localized wavefunction (BLW) computations reveal that hydrogen bonded phenol rings exhibit increased ring π-electron delocalization energies compared to the free phenol monomer. This additional stabilization may explain the stronger than expected proton donating ability of phenol.

  1. Changes of turbidity during the phenol oxidation by photo-Fenton treatment.

    Science.gov (United States)

    Villota, Natalia; Camarero, Luis M; Lomas, Jose M; Perez, Jonatan

    2014-11-01

    Turbidity presented by phenol solutions oxidized with Fenton reagent shows the tendency of a first order intermediate kinetics. Thus, turbidity can be considered a representative parameter of the presence of intermediate oxidation species, which are generated along the decomposition of toxic and reluctant contaminants, such as phenol. Moreover, that parameter presents a linear dependence with the catalyst dosage, but is also determined by the initial contaminant load. When analyzing the oxidation mechanism of phenol, it is found that the maximum turbidity occurs when the treatment is carried out at oxidant to phenol molar ratios R = 4.0. These oxidation conditions correspond to the presence of a reaction mixture mainly composed of dihydroxylated rings, precursors of the muconic acid formation. The oxidation via "para" comprises the formation reactions of charge transfer complexes (quinhydrone), between the para-dihydroxylated intermediates (hydroquinone) and the para-substituted quinones (p-benzoquinone), which are quite unstable and reactive species, quickly decomposed into hydroxyhydroquinones. Working with oxidant ratios up to R = 6.0, the maximum observed value of turbidity in the oxidized solutions is kept almost constant. It is found that, in these conditions, the pyrogallol formation is maximal, what is generated through the degradation of ortho-species (catechol and ortho-benzoquinone) and meta-substituted (resorcinol). Operating with ratios over R = 6.0, these intermediates are decomposed into biodegradable acids, generating lower turbidity in the solution. Then, the residual turbidity is a function of the molar ratio of the ferrous ions vs. moles of oxidant utilized in the essays, that lets to estimate the stoichiometric dosage of catalyst as 20 mg/L at pH = 3.0, whereas operating in stoichiometric conditions, R = 14.0, the residual turbidity of water results almost null.

  2. Interspecific variation in total phenolic content in temperate brown algae

    Directory of Open Access Journals (Sweden)

    Anna Maria Mannino

    2017-09-01

    Full Text Available Marine algae synthesize secondary metabolites such as polyphenols that function as defense and protection mechanisms. Among brown algae, Fucales and Dictyotales (Phaeophyceae contain the highest levels of phenolic compounds, mainly phlorotannins, that play multiple roles. Four temperate brown algae (Cystoseira amentacea, Cystoseira compressa, Dictyopteris polypodioides and Padina pavonica were studied for total phenolic contents. Total phenolic content was determined colorimetrically with the Folin-Ciocalteu reagent. Significant differences in total phenolic content were observed between leathery and sheetlike algae and also within each morphological group. Among the four species, the sheet-like alga D. polypodioides, living in the upper infralittoral zone, showed the highest concentration of phenolic compounds. These results are in agreement with the hypothesis that total phenolic content in temperate brown algae is influenced by a combination of several factors, such as growth form, depth, and exposition to solar radiation.

  3. Phenolic Compounds Analysis of Root, Stalk, and Leaves of Nettle

    Directory of Open Access Journals (Sweden)

    Semih Otles

    2012-01-01

    Full Text Available Types of nettles (Urtica dioica were collected from different regions to analyze phenolic compounds in this research. Nettles are specially grown in the coastal part. According to this kind of properties, nettle samples were collected from coastal part of (Mediterranean, Aegean, Black sea, and Marmara Turkey. Phenolic profile, total phenol compounds, and antioxidant activities of nettle samples were analyzed. Nettles were separated to the part of root, stalk, and leaves. Then, these parts of nettle were analyzed to understand the difference of phenolic compounds and amount of them. Nettle (root, stalk and leaves samples were analyzed by using High-Performance Liquid Chromatography with Diode-Array Detection (HPLC-DAD to qualitative and quantitative determination of the phenolic compounds. Total phenolic components were measured by using Folin-Ciocalteu method. The antioxidant activity was measured by using DPPH (2,2-diphenyl-1-picrylhydrazyl which is generally used for herbal samples and based on single electron transfer (SET.

  4. The Health Benefiting Mechanisms of Virgin Olive Oil Phenolic Compounds

    Directory of Open Access Journals (Sweden)

    Lisa Parkinson

    2016-12-01

    Full Text Available Virgin olive oil (VOO is credited as being one of the many healthful components associated with the Mediterranean diet. Mediterranean populations experience reduced incidence of chronic inflammatory disease states and VOO is readily consumed as part of an everyday Mediterranean dietary pattern. VOO is rich in phenolic compounds and the health promoting benefits of these phenolics are now established. Recent studies have highlighted the biological properties of VOO phenolic compounds elucidating their anti-inflammatory activities. This paper will review current knowledge on the anti-inflammatory and nutrigenomic, chemoprotective and anti-atherosclerotic activities of VOO phenolics. In addition the concentration, metabolism and bioavailability of specific phenolic compounds will be discussed. The evidence presented in the review concludes that oleurepein, hydroxytyrosol and oleocanthal have potent pharmacological activities in vitro and in vivo; however, intervention studies with biologically relevant concentrations of these phenolic compounds are required.

  5. The Health Benefiting Mechanisms of Virgin Olive Oil Phenolic Compounds.

    Science.gov (United States)

    Parkinson, Lisa; Cicerale, Sara

    2016-12-16

    Virgin olive oil (VOO) is credited as being one of the many healthful components associated with the Mediterranean diet. Mediterranean populations experience reduced incidence of chronic inflammatory disease states and VOO is readily consumed as part of an everyday Mediterranean dietary pattern. VOO is rich in phenolic compounds and the health promoting benefits of these phenolics are now established. Recent studies have highlighted the biological properties of VOO phenolic compounds elucidating their anti-inflammatory activities. This paper will review current knowledge on the anti-inflammatory and nutrigenomic, chemoprotective and anti-atherosclerotic activities of VOO phenolics. In addition the concentration, metabolism and bioavailability of specific phenolic compounds will be discussed. The evidence presented in the review concludes that oleurepein, hydroxytyrosol and oleocanthal have potent pharmacological activities in vitro and in vivo; however, intervention studies with biologically relevant concentrations of these phenolic compounds are required.

  6. Introducing Electronic Reports. Connecting Scholarship Series.

    Science.gov (United States)

    Pomeroy, Robert W.

    Designed to be a "road map," this guide introduces an approach to producing "electronic reports," documents that fuse computer-based methods with traditional research techniques. The guide emphasizes four stages--planning, inquiry, analysis, and expression. The chapter on planning discusses defining objectives, flowcharting,…

  7. Introducing Grounded Theory into translation studies | Wehrmeyer ...

    African Journals Online (AJOL)

    This article introduces tenets of Grounded Theory into a reception-oriented model for translation studies, in which the basis of comparison (tertium comparationis) between source and target texts is constructed from target audience expectancy norms. The model is primarily designed for projects where conformity to target ...

  8. Optimization of breeding methods when introducing multiple ...

    African Journals Online (AJOL)

    Optimization of breeding methods when introducing multiple resistance genes from American to Chinese wheat. JN Qi, X Zhang, C Yin, H Li, F Lin. Abstract. Stripe rust is one of the most destructive diseases of wheat worldwide. Growing resistant cultivars with resistance genes is the most effective method to control this ...

  9. Introducing the Adherence Strategy Engineering Framework (ASEF)

    DEFF Research Database (Denmark)

    Wagner, Stefan Rahr; Toftegaard, Thomas Skjødeberg; Bertelsen, Olav W.

    2013-01-01

    resulting in reduced data quality and suboptimal treatment. Objectives: The aim of this paper is to introduce the Adherence Strategy Engineering Framework (ASEF) as a method for developing novel technology-based adherence strategies to assess and improve patient adherence levels in the unsupervised setting...

  10. Introducing fluid dynamics using dimensional analysis

    DEFF Research Database (Denmark)

    Jensen, Jens Højgaard

    2013-01-01

    Many aspects of fluid dynamics can be introduced using dimensional analysis, combined with some basic physical principles. This approach is concise and allows exploration of both the laminar and turbulent limits—including important phenomena that are not normally dealt with when fluid dynamics...

  11. Introducing new agricultural technologies and marketing strategies ...

    African Journals Online (AJOL)

    Introducing new agricultural technologies and marketing strategies: A means for increasing income and nutrition of farm households in Ethiopia. ... Both the treatment of the nutritional deficits and the decision making criteria defined by farmers are expected to be useful techniques in other developing country technology ...

  12. Hybridisation between native Oreochromis species and introduced ...

    African Journals Online (AJOL)

    The Nile tilapia Oreochromis niloticus has been introduced throughout Africa outside its native range for aquaculture purposes. Hybridisation between escaped O. niloticus and native Oreochromis species is of concern due to potential negative effects on wild genetic resources for conservation, aquaculture and capture ...

  13. Introduce Construction Technology through Home Inspection

    Science.gov (United States)

    Wiggins, Enrique R.

    2007-01-01

    Introducing technology education students to the field of home inspection gives them a great opportunity to learn about and apply construction technology content. In working with his 8th-grade students, the author covers the purpose of a home inspection, the dynamic of home inspections, the process involved in inspecting schools and homes and…

  14. Introducing Technology Education at the Elementary Level

    Science.gov (United States)

    McKnight, Sean

    2012-01-01

    Many school districts are seeing a need to introduce technology education to students at the elementary level. Pennsylvania's Penn Manor School District is one of them. Pennsylvania has updated science and technology standards for grades 3-8, and after several conversations the author had with elementary principals and the assistant superintendent…

  15. Introducing Complex Systems into the Mathematics Curriculum

    Science.gov (United States)

    English, Lyn D.

    2008-01-01

    Children live in a highly sophisticated world composed of interlocking complex systems. An appreciation and understanding of such systems is critical for making effective decisions about everyone's lives as individuals and as community members. This article addresses one approach to introducing children of all achievement levels to introductory…

  16. Introducing Micro-finance in Sweden

    DEFF Research Database (Denmark)

    Barinaga, Ester

    2013-01-01

    The case describes the first year of efforts to introduce microfinance as a tool to work with vulnerable groups in Sweden, more particularly ex-convicts, former drug-addicts and longterm unemployed women of immigrant background. The teaching objective is to discuss whether micro-finance can be seen...

  17. The Wedding Project: Introducing the Project Approach

    Science.gov (United States)

    Sorrels, Barbara; Norris, Deborah; Sheeran, Linda

    2004-01-01

    Constructivist education, based on the theories of Piaget and Vygotsky, advocates an approach to curriculum and teaching that is student centered, inquiry based, integrated and intellectually engaging. One teaching strategy that provides such an experience is the Project Approach, reflective of the pedagogy of John Dewey and introduced as a model…

  18. Effects of extrusion, infrared and microwave processing on Maillard reaction products and phenolic compounds in soybean.

    Science.gov (United States)

    Zilić, Slađana; Mogol, Burçe Ataç; Akıllıoğlu, Gül; Serpen, Arda; Delić, Nenad; Gökmen, Vural

    2014-01-15

    The Maillard reaction indicators furosine, hydroxymethylfurfural (HMF), acrylamide and color were determined to evaluate heat effects induced during extrusion, infrared and microwave heating of soybean. In addition, the present paper aimed to study changes in the phenolic compounds, as well as in the overall antioxidant properties of different soybean products in relation to heating at 45-140 °C during the processes. Soybean proteins were highly sensible to Maillard reaction and furosine was rapidly formed under slight heating conditions during extrusion and infrared heating. Microwave heating at lower temperatures for a longer time yielded lower acrylamide levels in the final soybean products, as a result of its partial degradation. However, during infrared heating, acrylamide formation greatly increased with decreasing moisture content. After a short time of extrusion and infrared heating at 140 °C and microwave heating at 135 °C for 5 min, concentrations of HMF increased to 11.34, 26.21 and 34.97 µg g(-1), respectively. The heating conditions caused formation of acrylamide, HMF and furosine in high concentration. The results indicate that the complex structure of soybeans provides protection of phenolic compounds from thermal degradation, and that Maillard reaction products improved the antioxidant properties of heat-treated soybean. © 2013 Society of Chemical Industry.

  19. Phenolic Compounds Analysis of Root, Stalk, and Leaves of Nettle

    OpenAIRE

    Otles, Semih; Yalcin, Buket

    2012-01-01

    Types of nettles (Urtica dioica) were collected from different regions to analyze phenolic compounds in this research. Nettles are specially grown in the coastal part. According to this kind of properties, nettle samples were collected from coastal part of (Mediterranean, Aegean, Black sea, and Marmara) Turkey. Phenolic profile, total phenol compounds, and antioxidant activities of nettle samples were analyzed. Nettles were separated to the part of root, stalk, and leaves. Then, these parts ...

  20. Syntrophy in Methanogenic Degradation

    NARCIS (Netherlands)

    Worm, P.; Müller, N.; Plugge, C.M.; Stams, A.J.M.; Schink, B.

    2010-01-01

    This chapter deals with microbial communities of bacteria and archaea that closely cooperate in methanogenic degradation and perform metabolic functions in this community that neither one of them could carry out alone. The methanogenic degradation of fatty acids, alcohols, most aromatic compounds,

  1. Degradations and Rearrangement Reactions

    Science.gov (United States)

    Zhang, Jianbo

    This section deals with recent reports concerning degradation and rearrangement reactions of free sugars as well as some glycosides. The transformations are classified in chemical and enzymatic ways. In addition, the Maillard reaction will be discussed as an example of degradation and rearrangement transformation and its application in current research in the fields of chemistry and biology.

  2. Modelling of Phenol Contamination in Wonorejo Estuary, Indonesia

    Science.gov (United States)

    Suntoyo; Sakinah, W.

    2017-07-01

    Phenol as a part of marine pollution in Wonorejo estuary has been a concern today. Mass death of clams and decreasing growth of shrimps often occur in this area. The citizens made assumption that source of marine pollution from Sidoarjo mud disaster. This paper investigates the distribution of phenol from modelling with MIKE 21, Eco Lab module. Measurement were done in Wonorejo estuary to get a validation of modelling. Modelling result shows phenol concentration in northern Wonorejo estuary is higher than other areas. Hence, it was concluded that the phenol source is not from Sidoarjo mud disaster.

  3. Peroxidase extraction from jicama skin peels for phenol removal

    Science.gov (United States)

    Chiong, T.; Lau, S. Y.; Khor, E. H.; Danquah, M. K.

    2016-06-01

    Phenol and its derivatives exist in various types of industrial effluents, and are known to be harmful to aquatic lives even at low concentrations. Conventional treatment technologies for phenol removal are challenged with long retention time, high energy consumption and process cost. Enzymatic treatment has emerged as an alternative technology for phenol removal from wastewater. These enzymes interact with aromatic compounds including phenols in the presence of hydrogen peroxide, forming free radicals which polymerize spontaneously to produce insoluble phenolic polymers. This work aims to extract peroxidase from agricultural wastes materials and establish its application for phenol removal. Peroxidase was extracted from jicama skin peels under varying extraction conditions of pH, sample-to-buffer ratio (w/v %) and temperature. Experimental results showed that extraction process conducted at pH 10, 40% w/v and 25oC demonstrated a peroxidase activity of 0.79 U/mL. Elevated temperatures slightly enhanced the peroxidase activities. Jicama peroxidase extracted at optimum extraction conditions demonstrated a phenol removal efficiency of 87.5% at pH 7. Phenol removal efficiency was ∼ 97% in the range of 30 - 40oC, and H2O2 dosage has to be kept below 100 mM for maximum removal under phenol concentration tested.

  4. Cytotoxicity of Phenol Red in Toxicity Assays for Carbon Nanoparticles

    Directory of Open Access Journals (Sweden)

    Chunhai Fan

    2012-09-01

    Full Text Available To explore the novel properties of carbon nanoparticles (CNPs in nanotoxicity assays, the adsorption of phenol red (a pH indicator for culture medium by multi-walled carbon nanotubes (MWNTs and three kinds of carbon blacks (CBs with nanosize, and its effects on cytotoxicity were studied. Results indicated that the phenol red adsorbed and delivered into cells by CBs was responsible for the toxicity to Hela cells in the medium without serum. The cellular uptake of phenol red was verified using 125I-labeling techniques. The size-dependent cytotoxicity of CBs was found to closely correlate to adsorption of phenol red, cellular uptake of phenol red-CB complexes and the amount of phenol red delivered into the cells by CBs. Although the CBs were either nontoxic or slightly toxic, as vehicles of phenol red, they played an essential role in the cytotoxicity induced by phenol red. However, MWNTs showed an intrinsic cytotoxicity independent of phenol red. The implications associated with these findings are discussed.

  5. Performance evaluation of organic emulsion liquid membrane on phenol removal.

    Science.gov (United States)

    Ng, Y S; Jayakumar, N S; Hashim, M A

    2010-12-15

    The percentage removal of phenol from aqueous solution by emulsion liquid membrane and emulsion leakage was investigated experimentally for various parameters such as membrane:internal phase ratio, membrane:external phase ratio, emulsification speed, emulsification time, carrier concentration, surfactant concentration and internal agent concentration. These parameters strongly influence the percentage removal of phenol and emulsion leakage. Under optimum membrane properties, the percentage removal of phenol was as high as 98.33%, with emulsion leakage of 1.25%. It was also found that the necessity of carrier for enhancing phenol removal was strongly dependent on the internal agent concentration. Copyright © 2010 Elsevier B.V. All rights reserved.

  6. Rapid determination of phenol content in extra virgin olive oil

    Directory of Open Access Journals (Sweden)

    Favati, F.

    1994-04-01

    Full Text Available A quick extraction methodology was developed to reduce the time usually required to determine the phenol content in olive oil. The validity of this method, based on SPE technique, was tested against two other phenol extraction techniques.
    The statistical analysis of the analytical data showed that over a phenol content range of 110-550 μg/g oil, the proposed method can be a reliable alternative for a rapid extraction of the phenols from olive oil.

    No disponible.

  7. Chlorine dioxide as phenol and H2S scavenger - formation of halogenated phenols and subsequent environmental risk

    Energy Technology Data Exchange (ETDEWEB)

    Melbye, Alf G.; Faksness, Liv-Guri; Knudsen, Boerre Leif

    2006-03-15

    Formation of halogenated phenols as side products from treatment of produced water with aqueous chlorine dioxide has been investigated. The literature describes formation of halogenated hydrocarbons in effluent treatment using chlorine, hypochlorite and chlorine dioxide. A new chlorine dioxide product, originally intended as a H2S scavenger in the oil and gas industry, has been tested both as a phenol scavenger and H2S-scavenger for produced water applications. The concern about the possible formation of halogenated by-products initiated laboratory testing of chlorine dioxide as phenol and H2S scavenger for produced water applications. The tests also included synthetic matrixes containing phenols, and the tests show that halogenated phenols, mainly brominated species, are found in produced water after treatment with chlorine dioxide. Due to potential environmental risk from halogenated organic contaminants, the use of chlorine dioxide as phenol and H2S scavenger is not recommended. (Author)

  8. Study of the interactions between Eu(III) and Al2O3 particles in the presence of phenolic acids

    International Nuclear Information System (INIS)

    Moreau, P.

    2012-01-01

    In the framework of environmental pollution by radionuclides, this work was focused on the interactions occurring in systems containing europium(III) - as a chemical analogue for the actinides Am(III) and Cm(III) -, phenolic acids - lignin degradation products and anti-fungi, naturally occurring in soils, and alumina - representative of sorption sites found in the environment. This study was conducted at different scales of description: the macroscopic scale - to quantify Eu(III) and/or phenolic acids adsorption onto the mineral surface -, and the microscopic scale - to study the chemical environment of Eu(III) using Time-Resolved Luminescence Spectroscopy (TRLS). First, the binary systems, i.e. systems containing only two entities among the three previously cited, were characterized. Complexation constants of Eu(III) by three phenolic acids (4-hydroxybenzoic, 3,4-dihydroxybenzoic, and 3,4,5-trihydroxybenzoic acids) were determined and quantum calculations (DFT) were carried out on La(III)-acid complex analogues. Sorption of the acids onto aluminol sites was modelled using surface complexation concepts. Analyses of two ternary systems (containing 4-hydroxybenzoic and 3,4-dihydroxybenzoic acids) revealed synergistic processes for Eu(III) and phenolic acids sorption onto Al 2 O 3 . A spectral fingerprint of ternary complex involving Eu(III)/4-hydroxybenzoic acid/Al 2 O 3 surface sites was evidenced. (author) [fr

  9. Exposure to phenols, parabens and UV filters

    DEFF Research Database (Denmark)

    Joensen, Ulla N.; Jørgensen, Niels; Thyssen, Jacob P.

    2017-01-01

    Concentrations of eight simple phenols, six parabens and nine UV filters were analysed in urine from 65 FLG loss-of-function mutation carriers and 130 non-carriers (controls). Regression analyses, controlling for urinary dilution and confounders, were performed to estimate associations between FLG mutation...... status and chemical concentrations in urine. Results FLG mutation carriers had 80% (13–180%) higher urinary concentrations of methyl paraben (MeP) and 91% (13–219%) higher concentrations of n-propyl paraben (n-PrP) than controls. For 13 compounds, levels were higher in FLG mutation carriers, although...

  10. Kinetics of Phenol Oxidation by Candidateopicalis: Effect of Oxygen Supply Rate and Nutrients on Phenol Inhibition

    Czech Academy of Sciences Publication Activity Database

    Páca, J.; Komárková, E.; Prell, Aleš; Stiborová, M.; Sobotka, Miroslav

    2002-01-01

    Roč. 47, č. 6 (2002), s. 701-707 ISSN 0015-5632 R&D Projects: GA ČR GA104/00/0575 Keywords : phenol oxidation * candida tropicalis Subject RIV: EE - Microbiology, Virology Impact factor: 0.979, year: 2002

  11. Utilizing the phenol byproducts of coke production: 3. Phenols as coinhibitors of thermopolymerization during styrene production

    Energy Technology Data Exchange (ETDEWEB)

    I.I. Batura; A.F. Gogotov; V.I. Cherepanov; O.I. Baranov; A.A. Levchuk; M.V. Parilova [Irkutsk State Technical University, Irkutsk (Russian Federation)

    2009-01-15

    A new oligomerization procedure for phenol byproducts from coke production is experimentally studied. This method, oxidative combination, is intended to produce an effective coinhibitor of styrene thermopolymerization. When combined with a Mannich base, the new oligomer exhibits excellent inhibiting properties in the heat treatment of styrene and matches the effectiveness of imported inhibitors based on nitroxyl radicals. 15 refs., 1 tab.

  12. Full scale treatment of phenolic coke coking waste water under unsteady conditions

    Energy Technology Data Exchange (ETDEWEB)

    Suschka, Jan [Institute for Ecology of Industrial Areas, Katowice (Poland); Morel, Jacek; Mierzwinski, Stanislaw; Januszek, Ryszard [Coke Plant Przyjazn, Dabrowa Gornicza (Poland)

    1993-12-31

    Phenolic waste water from the largest coke coking plant in Poland is treated at a full technical scale. From the very beginning it became evident that very high qualitative variations in short and long periods were to be expected. For this purpose, the biological treatment plant based on activated sludge is protected through preliminary physical-chemical treatment and the results are secured by a final chemical stage of treatment. Nevertheless, improvements in the performance of the treatment plant have been found necessary to introduce. In this work, the experience gained over the last five years is described and developed improvements were presented. 3 refs., 9 figs., 1 tab.

  13. [Reductive degradation of chlorophenols in aqueous solution by gamma irradiation].

    Science.gov (United States)

    Peng, Yun-Xia; He, Shi-Jun; Gong, Wen-Qi; Wang, Jian-Long

    2013-04-01

    Because chlorine is an electron withdrawing group, the highly chlorinated phenols may react quickly with hydrated electrons rather than with hydroxyl radicals. The process of reactions of four chlorophenols (4-CP, 2-CP, 2,4-DCP, 2,4,6-TCP) with e(aq)(-) was investigated in aqueous solutions by detecting the concentration of CPs, Cl- and intermediates. In the e(aq)(-) reductive system, the experimental results showed that the order of four kinds of chlorophenol degradation and dechlorination was 2,4,6-TCP > 2,4-DCP > 2-CP > 4-CP. The greater the chlorine content was the higher reactivity of hydrated electrons towards chlorophenols was. Furthermore, hydrated electrons may preferentially attack the ortho-position of chlorine atom rather than the para-position of chlorine atom. Phenol and Cl- were detected as the final product of the reductive reaction. Additionally, processes of degradation and dechlorination of CPs were observed as the pseudo-first-order kinetics. The reaction constant of degradation of 4-CP, 2-CP, 2,4-DCP and 2,4,6-TCP were 0.154, 0.253, 0.750 and 1.188 kGy(-1), respectively. Meanwhile, the dechlorination of 4-CP, 2-CP, 2,4-DCP and 2,4,6-TCP were 0.137, 0.219, 0.251 and 0.306 kGy(-1), respectively.

  14. Bursting in the Belousov-Zhabotinsky Reaction added with Phenol in a Batch Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Cadena, Ariel; Agreda, Jesus, E-mail: jaagredab@unal.edu.co [Departamento de Quimica, Facultad de Ciencias, Universidad Nacional de Colombia, Bogota (Colombia); Barragan, Daniel [Escuela de Quimica, Facultad de Ciencias, Universidad Nacional de Colombia, Medellin (Colombia)

    2013-12-01

    The classic Belousov-Zhabotinski reaction was modified by adding phenol as a second organic substrate that kinetically competes with the malonic acid in the reduction of Ce{sup 4+} to Ce{sup 3+} and in the removal of molecular bromine of the reaction mixture. The oscillating reaction of two substrates exhibited burst firing and an oscillatory period of long duration. Analysis of experimental data shows an increasing of the bursting phenomenon, with a greater spiking in the burst firing and with a longer quiescent state, as a function of the initial phenol concentration increase. It was hypothesized that the bursting phenomenon can be explained introducing a redox cycle between the reduced phenolic species (hydroxyphenols) and the oxidized ones (quinones). The hypothesis was experimentally and numerically tested and from the results it is possible to conclude that the bursting phenomenon exhibited by the oscillating reaction of two substrates is mainly driven by a p-di-hydroxy-benzene/p-benzoquinone redox cycle (author)

  15. Influence of heat and moisture treatment on carotenoids, phenolic content, and antioxidant capacity of orange maize flour.

    Science.gov (United States)

    Beta, Trust; Hwang, Taeyoung

    2018-04-25

    The aim of this work was to study the effect of heat and moisture treatment (HMT) on carotenoids, phenolic content and antioxidant capacity of ground, orange maize. Total carotenoid content (TCC) of untreated sample (53.39 mg/kg) was 2.2 times higher than measured in treated orange maize f (24.61 mg/kg). The rates of degradation with HMT were in the following order: β-carotene > β-cryptoxanthin > zeaxanthin > lutein. There was a significant interaction between longer heating time and higher moisture content on carotenoid degradation (p < .05). Total phenolic content (TPC) in raw sample (1664.74 mg/kg) was two-fold higher than in treated orange maize (827.89 mg/kg). Ferulic acid was the most abundant and stable phenolic acid in raw and treated orange maize. The antioxidant capacity of orange maize was higher in methanol than in butanol extracts. The highest correlation (0.924) was observed between TPC and ABTS+ scavenging capacity of methanol extracts. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Comparative analysis of the complete genome of an Acinetobacter calcoaceticus strain adapted to a phenol-polluted environment.

    Science.gov (United States)

    Zhan, Yuhua; Yan, Yongliang; Zhang, Wei; Chen, Ming; Lu, Wei; Ping, Shuzhen; Lin, Min

    2012-01-01

    The complete genome sequence of Acinetobacter calcoaceticus PHEA-2, a non-pathogenic phenol-degrading bacterium previously isolated from industrial wastewater of an oil refinery in China, has been established. This is the first sequence of an A. calcoaceticus strain. We report here a comparative genomic analysis of PHEA-2 with two other Acinetobacter species having different lifestyles, Acinetobacter baumannii AYE, a pathogenic human-adapted strain, and Acinetobacter baylyi ADP1, a soil-living strain. For a long time, A. calcoaceticus could not be easily distinguished from A. baumannii strains. Indeed, whole-genome comparison revealed high synteny between A. calcoaceticus and A. baumannii genomes, but most genes for multiple drug resistance as well as those presumably involved in pathogenicity were not present in the PHEA-2 genome and phylogenetic analysis showed that A. calcoaceticus differed from A. baumannii antibiotic-susceptible strains. It also revealed that many genes associated with environmental adaptation were acquired by horizontal gene transfer, including an 8-kb phenol degradation gene cluster. A relatively higher proportion of transport-related proteins were found in PHEA-2 than in ADP1 and AYE. Overall, these findings highlight the remarkable capacity of A. calcoaceticus PHEA-2 to effectively adapt to a phenol-polluted wastewater environment. Copyright © 2011 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  17. The challenges of introducing internal social media

    DEFF Research Database (Denmark)

    Madsen, Vibeke Thøis

    2017-01-01

    Purpose – The purpose of this paper is to explore the challenges associated with introducing internal social media (ISM) into organizations in order to help them reap the benefits of coworker communication on ISM. Design/methodology/approach – The paper is based on an exploratory study in ten...... facilitators and sense-givers. Keywords Organizational communication, Internal communication, Coworker, Internal social media Paper type Research paper...

  18. Introducing the new business demography statistics

    OpenAIRE

    Karen Grierson; Andrew Allen

    2008-01-01

    Introducing the new business demography statisticsA new National Statistics series waspublished on 28 November 2008 bythe Offi ce for National Statistics (ONS),providing data on business births,deaths and survival rates, called BusinessDemography: Enterprise Births andDeaths. The Department for Business,Enterprise & Regulatory Reform (BERR)also published its series Business start upsand closures: VAT registrations andde-registrations in 2007 on the sameday. The year 2008 is the final update t...

  19. Introducing carbon taxes in South Africa

    International Nuclear Information System (INIS)

    Alton, Theresa; Arndt, Channing; Davies, Rob; Hartley, Faaiqa; Makrelov, Konstantin; Thurlow, James; Ubogu, Dumebi

    2014-01-01

    Highlights: • South Africa is considering introducing a carbon tax to reduce greenhouse gas emissions. • A phased-in tax of US$30 per ton can achieve national emissions reductions targets set for 2025. • Ignoring all potential benefits, the tax reduces national welfare by about 1.2 percent in 2025. • Border carbon adjustments reduce welfare losses while maintaining emissions reductions. • The mode for recycling carbon tax revenues strongly influences distributional outcomes. - Abstract: South Africa is considering introducing a carbon tax to reduce greenhouse gas emissions. Following a discussion of the motivations for considering a carbon tax, we evaluate potential impacts using a dynamic economywide model linked to an energy sector model including a detailed evaluation of border carbon adjustments. Results indicate that a phased-in carbon tax of US$30 per ton of CO 2 can achieve national emissions reductions targets set for 2025. Relative to a baseline with free disposal of CO 2 , constant world prices and no change in trading partner behavior, the preferred tax scenario reduces national welfare and employment by about 1.2 and 0.6 percent, respectively. However, if trading partners unilaterally impose a carbon consumption tax on South African exports, then welfare/employment losses exceed those from a domestic carbon tax. South Africa can lessen welfare/employment losses by introducing its own border carbon adjustments. The mode for recycling carbon tax revenues strongly influences distributional outcomes, with tradeoffs between growth and equity

  20. Introduced mammals on Western Indian Ocean islands

    Directory of Open Access Journals (Sweden)

    James C. Russell

    2016-04-01

    Full Text Available The diversity of introduced mammals and their introduction history varies greatly across the Western Indian Ocean (WIO islands, from ancient introductions in the past millennia on islands off the East coast of Africa where extant terrestrial native mammal communities exist, to very recent invasions in the past decades on islands in the Mascarene archipelago. We compile the distribution of 16 introduced mammal taxa on 28 island groups comprising almost 2000 islands. Through an exhaustive literature review and expert consultation process we recorded all mammal eradications, and species recoveries which could be attributed to introduced mammal eradication or control. All island groups have been invaded by mammals, and invasive cats and rats in particular are ubiquitous, but cultural contingency has also led to regional invasions by other mammals such as lemurs, civets and tenrecs. Mammal eradications have been attempted on 45 islands in the WIO, the majority in the Seychelles and Mauritius, and where successful have resulted in spectacular recovery of species and ecosystems. Invasive mammalian predator eradication or control in association with habitat management has led to improved conservation prospects for at least 24 species, and IUCN red-list down-listing of eight species, in the Mascarene Islands. Future island conservation prioritisation in the region will need to take account of global climate change and predicted sea-level rises and coastal inundation. Greater investment and prioritisation in island conservation in the region is warranted, given its high biodiversity values and the extent of invasions.

  1. In-Depth Two-Year Study of Phenolic Profile Variability among Olive Oils from Autochthonous and Mediterranean Varieties in Morocco, as Revealed by a LC-MS Chemometric Profiling Approach

    Science.gov (United States)

    Bajoub, Aadil; Medina-Rodríguez, Santiago; Olmo-García, Lucía; Ajal, El Amine; Monasterio, Romina P.; Hanine, Hafida; Fernández-Gutiérrez, Alberto; Carrasco-Pancorbo, Alegría

    2016-01-01

    Olive oil phenolic fraction considerably contributes to the sensory quality and nutritional value of this foodstuff. Herein, the phenolic fraction of 203 olive oil samples extracted from fruits of four autochthonous Moroccan cultivars (“Picholine Marocaine”, “Dahbia”, “Haouzia” and “Menara”), and nine Mediterranean varieties recently introduced in Morocco (“Arbequina”, “Arbosana”, “Cornicabra”, “Frantoio”, “Hojiblanca”, “Koroneiki”, “Manzanilla”, “Picholine de Languedoc” and “Picual”), were explored over two consecutive crop seasons (2012/2013 and 2013/2014) by using liquid chromatography-mass spectrometry. A total of 32 phenolic compounds (and quinic acid), belonging to five chemical classes (secoiridoids, simple phenols, flavonoids, lignans and phenolic acids) were identified and quantified. Phenolic profiling revealed that the determined phenolic compounds showed variety-dependent levels, being, at the same time, significantly affected by the crop season. Moreover, based on the obtained phenolic composition and chemometric linear discriminant analysis, statistical models were obtained allowing a very satisfactory classification and prediction of the varietal origin of the studied oils. PMID:28036024

  2. In-Depth Two-Year Study of Phenolic Profile Variability among Olive Oils from Autochthonous and Mediterranean Varieties in Morocco, as Revealed by a LC-MS Chemometric Profiling Approach

    Directory of Open Access Journals (Sweden)

    Aadil Bajoub

    2016-12-01

    Full Text Available Olive oil phenolic fraction considerably contributes to the sensory quality and nutritional value of this foodstuff. Herein, the phenolic fraction of 203 olive oil samples extracted from fruits of four autochthonous Moroccan cultivars (“Picholine Marocaine”, “Dahbia”, “Haouzia” and “Menara”, and nine Mediterranean varieties recently introduced in Morocco (“Arbequina”, “Arbosana”, “Cornicabra”, “Frantoio”, “Hojiblanca”, “Koroneiki”, “Manzanilla”, “Picholine de Languedoc” and “Picual”, were explored over two consecutive crop seasons (2012/2013 and 2013/2014 by using liquid chromatography-mass spectrometry. A total of 32 phenolic compounds (and quinic acid, belonging to five chemical classes (secoiridoids, simple phenols, flavonoids, lignans and phenolic acids were identified and quantified. Phenolic profiling revealed that the determined phenolic compounds showed variety-dependent levels, being, at the same time, significantly affected by the crop season. Moreover, based on the obtained phenolic composition and chemometric linear discriminant analysis, statistical models were obtained allowing a very satisfactory classification and prediction of the varietal origin of the studied oils.

  3. QSARs for phenols and phenolates: oxidation potential as a predictor of reaction rate constants with photochemically produced oxidants.

    Science.gov (United States)

    Arnold, William A; Oueis, Yan; O'Connor, Meghan; Rinaman, Johanna E; Taggart, Miranda G; McCarthy, Rachel E; Foster, Kimberley A; Latch, Douglas E

    2017-03-22

    Quantitative structure-activity relationships (QSARs) for prediction of the reaction rate constants of phenols and phenolates with three photochemically produced oxidants, singlet oxygen, carbonate radical, and triplet excited state sensitizers/organic matter, are developed. The predictive variable is the one-electron oxidation potential (E 1 ), which is calculated for each species using density functional theory. The reaction rate constants are obtained from the literature, and for singlet oxygen, are augmented with new experimental data. Calculated E 1 values have a mean unsigned error compared to literature values of 0.04-0.06 V. For singlet oxygen, a single linear QSAR that includes both phenols and phenolates is developed that predicts experimental rate constants, on average, to within a factor of three. Predictions for only 6 out of 87 compounds are off by more than a factor of 10. A more limited data set for carbonate radical reactions with phenols and phenolates also gives a single linear QSAR with prediction of rate constant being accurate to within a factor of three. The data for the reactions of phenols with triplet state sensitizers demonstrate that two sensitizers, 2-acetonaphthone and methylene blue, most closely predict the reactivity trend of triplet excited state organic matter with phenols. Using sensitizers with stronger reduction potentials could lead to overestimation of rate constants and thus underestimation of phenolic pollutant persistence.

  4. Effects of Introduced Materials in the Drift Scale Test

    International Nuclear Information System (INIS)

    DeLoach, L; Jones, RL

    2002-01-01

    Water samples previously acquired from superheated (>140 C) zones within hydrological test boreholes of the Drift Scale Test (DST) show relatively high fluoride concentrations (5-66 ppm) and low pH (3.1-3.5) values. In these high temperature regions of the rock, water is present superheated vapor only--liquid water for sampling purposes is obtained during the sampling process by cooling. Based on data collected to date, it is evident that the source of the fluoride and low pH is from introduced man-made materials (Teflon(trademark) and/or Viton(trademark) fluoroelastomer) used in the test. The test materials may contribute fluoride either by degassing hydrogen fluoride (HF) directly to produce trace concentrations of HF gas (∼0.1 ppm) in the high temperature steam, or by leaching fluoride in the sampling tubes after condensation of the superheated steam. HF gas is known to be released from Viton(trademark) at high temperatures (Dupont Dow Elastomers L.L.C., Elkton, MD, personal communication) and the sample water compositions indicate near stoichiometric balance of hydrogen ion and fluoride ion, indicating dissolution of HF gas into the aqueous phase. These conclusions are based on a series of water samples collected to determine if the source of the fluoride is from the degradation of materials originally installed to facilitate measurements. Analyses of these water samples show that the source of the fluoride is the introduced materials, that is the Viton(trademark) packers used to isolate test zones and/or Teflon(trademark) tubing used to draw water and steam from the test zones. In particular, water samples collected from borehole (BH) 72 high temperatures (∼ 170 C) prior to introduction of any Viton(trademark) or Teflon(trademark) show pH Values (4.8 to 5.5) and fluoride concentrations well below 1 ppm over a period of six months. These characteristics are typical of condensing DST steam that contains only some dissolved carbon dioxide generated by water

  5. Convective drying kinetics of strawberry (Fragaria ananassa): Effects on antioxidant activity, anthocyanins and total phenolic content.

    Science.gov (United States)

    Méndez-Lagunas, Lilia; Rodríguez-Ramírez, Juan; Cruz-Gracida, Marlene; Sandoval-Torres, Sadoth; Barriada-Bernal, Gerardo

    2017-09-01

    The thermal drying effects on strawberries were investigated in terms of the kinetics of antioxidant activity (AA), anthocyanins (A) and total phenolic compound content (TPC), as well as the final colour. The evaluated drying temperatures were 50 and 60°C with an air rate of 1.5m/s. The 2,2-diphenyl-2-picryl-hydrazyl, pH differential and Folin-Ciocalteu methods were used to assess the antioxidant properties. The kinetics of TPC and AA showed an initial and final period of degradation attributed to inhibition of enzymes. A plateau between these two periods suggests that under certain conditions of temperature and water content, no degradation reactions occurred. Final losses of up to 74, 45 and 78% were found for AA, A and TPC, respectively. The total colour change (ΔE) was lesser degree at 60 than 50°C. Thermal degradation of the antioxidant compounds followed a first-order reaction kinetics and the degradation rate constants (k) were calculated. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Inhibition of lignin-derived phenolic compounds to cellulase.

    Science.gov (United States)

    Qin, Lei; Li, Wen-Chao; Liu, Li; Zhu, Jia-Qing; Li, Xia; Li, Bing-Zhi; Yuan, Ying-Jin

    2016-01-01

    Lignin-derived phenolic compounds are universal in the hydrolysate of pretreated lignocellulosic biomass. The phenolics reduce the efficiency of enzymatic hydrolysis and increase the cost of ethanol production. We investigated inhibition of phenolics on cellulase during enzymatic hydrolysis using vanillin as one of the typical lignin-derived phenolics and Avicel as cellulose substrate. As vanillin concentration increased from 0 to 10 mg/mL, cellulose conversion after 72-h enzymatic hydrolysis decreased from 53 to 26 %. Enzyme deactivation and precipitation were detected with the vanillin addition. The enzyme concentration and activity consecutively decreased during hydrolysis, but the inhibition degree, expressed as the ratio of the cellulose conversion without vanillin to the conversion with vanillin (A 0 /A), was almost independent on hydrolysis time. Inhibition can be mitigated by increasing cellulose loading or cellulase concentration. The inhibition degree showed linear relationship with the vanillin concentration and exponential relationship with the cellulose loading and the cellulase concentration. The addition of calcium chloride, BSA, and Tween 80 did not release the inhibition of vanillin significantly. pH and temperature for hydrolysis also showed no significant impact on inhibition degree. The presence of hydroxyl group, carbonyl group, and methoxy group in phenolics affected the inhibition degree. Besides phenolics concentration, other factors such as cellulose loading, enzyme concentration, and phenolic structure also affect the inhibition of cellulose conversion. Lignin-blocking agents have little effect on the inhibition effect of soluble phenolics, indicating that the inhibition mechanism of phenolics to enzyme is likely different from insoluble lignin. The inhibition of soluble phenolics can hardly be entirely removed by increasing enzyme concentration or adding blocking proteins due to the dispersity and multiple binding sites of phenolics

  7. Deterioration of Polyethylene Exposed to Chlorinated Species in Aqueous Phases : Test Methods, Antioxidants Consumption and Polymer Degradation

    OpenAIRE

    Yu, Wenbin

    2013-01-01

    This thesis presents a study of antioxidant depletion in water containing chlorinated species (water containing 10 ppm either Cl2 or ClO2, buffered to pH = 6.8), the degradation products in the aqueous phase, and polyethylene pipe degradation scenarios. A low molecular weight hydrocarbon analogue (squalane) was used instead of solid polyethylene as the host material for the antioxidants, and the depletion of antioxidants has been studied. The phenolic antioxidant Irganox 1010 was consumed ca....

  8. Phenolic compounds in Rosaceae fruits from Ecuador.

    Science.gov (United States)

    Vasco, Catalina; Riihinen, Kaisu; Ruales, Jenny; Kamal-Eldin, Afaf

    2009-02-25

    RP-HPLC-DAD was used to study the content of phenolic compounds in four Ecuadorian fruits (strawberry, Andean blackberry, plum, and capuli cherry). Compounds were identified using spectral characteristics of representative standards and reference samples. Further, LC-MS with MS/MS was used to confirm molecular assignments in previously unstudied capuli cherry. Gallic acid was detected in Andean blackberry, and galloyl esters were detected in strawberries. Both these berries contained ellagic acid derivatives as major compounds, followed by anthocyanins, cyanidin, and pelargonidin glycosides. Plums and capuli cherry showed similar profiles of phenolic compounds, with chlorogenic and neochlorogenic acids being the most important hydroxycinnamates. (-)-Epicatechin was found in high amounts in Andean blackberry, plums, and capuli cherry, while (+)-catechin was only found in capuli cherry. Proanthocyanidins were major compounds in all fruits, and all contained considerable amounts of quercetin derivatives and smaller amounts of kaempferol derivatives. LC-MS analysis of capuli cherry revealed dimeric and trimeric procyanidins, quercetin and kaempferol hexosides and pentosides, and a kaempferol-O,C-dipentoside.

  9. Degradation of 3-phenoxybenzoic acid by a Bacillus sp.

    Directory of Open Access Journals (Sweden)

    Shaohua Chen

    Full Text Available 3-Phenoxybenzoic acid (3-PBA is of great environmental concern with regards to endocrine disrupting activity and widespread occurrence in water and soil, yet little is known about microbial degradation in contaminated regions. We report here that a new bacterial strain isolated from soil, designated DG-02, was shown to degrade 95.6% of 50 mg·L(-1 3-PBA within 72 h in mineral salt medium (MSM. Strain DG-02 was identified as Bacillus sp. based on the morphology, physio-biochemical tests and 16S rRNA sequence. The optimum conditions for 3-PBA degradation were determined to be 30.9°C and pH 7.7 using response surface methodology (RSM. The isolate converted 3-PBA to produce 3-(2-methoxyphenoxy benzoic acid, protocatechuate, phenol, and 3,4-dihydroxy phenol, and subsequently transformed these compounds with a q(max, K(s and K(i of 0.8615 h(-1, 626.7842 mg·L(-1 and 6.7586 mg·L(-1, respectively. A novel microbial metabolic pathway for 3-PBA was proposed on the basis of these metabolites. Inoculation of strain DG-02 resulted in a higher degradation rate on 3-PBA than that observed in the non-inoculated soil. Moreover, the degradation process followed the first-order kinetics, and the half-life (t(1/2 for 3-PBA was greatly reduced as compared to the non-inoculated control. This study highlights an important potential application of strain DG-02 for the in situ bioremediation of 3-PBA contaminated environments.

  10. Degradation of recalcitrant organic contaminants by solar photocatalysis.

    Science.gov (United States)

    Mansouri, L; Bousselmi, L; Ghrabi, A

    2007-01-01

    Biological pre-treated landfill leachates of Djebel Chakir contains some macromolecular organic substances that are resistant to biological degradation. The aim of the present work is to assess the feasibility of removing refractory organic pollutants in biological pre-treated landfill leachate by solar photocatalyse process. Leachate pollutant contents are studied to assess their contribution to leachate pollution and their treatability by solar photocatalyse process. Phenol is chosen as model of pollutants, to evaluate its removal and the efficiency of the photocatalytic system. The experiments were carried out in suspended photocatalytic reactor, using TiO2 Degussa P25, under sunlight illumination (UV-A: 15-31 W/cm2). Under optimum operational conditions, applied to single reactant (phenol), the system presents a TOC removal of 90% (the degradation follows a first-order kinetic). Based on the TOC removal, the results shows that the degradation of biological pre-treated leachate follows a zero-order kinetic. After 5 h of sunlight exposure, 74% of COT is removed. The TOC removal is the best without any correction of the pH and at the TiO2 concentration of 2.5 g/L. The photocatalytic degradation of organic contaminants as well as the formation and disappearance of the by-products were followed by GC/MS. The solar photocatalysis processes induce several modifications of the matrix leading to more biodegradable forms: all the remaining and new compounds generated after the biological pre-treatment of leachate are degraded and other types of organics appear, mainly carboxylic acid, aliphatic hydrocarbons and phtalic acids.

  11. Influence of Forage Phenolics on Ruminal Fibrolytic Bacteria and In Vitro Fiber Degradation

    OpenAIRE

    Varel, Vincent H.; Jung, Hans-Joachim G.

    1986-01-01

    In vitro cultures of ruminal microorganisms were used to determine the effect of cinnamic acid and vanillin on the digestibility of cellulose and xylan. Cinnamic acid and vanillin depressed in vitro dry matter disappearance of cellulose 14 and 49%, respectively, when rumen fluid was the inoculum. The number of viable Bacteroides succinogenes cells, the predominant cellulolytic organism, was threefold higher for fermentations which contained vanillin than for control fermentations. When xylan ...

  12. Genome Sequence of Rhodococcus erythropolis Strain CCM2595, a Phenol Derivative-Degrading Bacterium

    Czech Academy of Sciences Publication Activity Database

    Strnad, Hynek; Pátek, Miroslav; Fousek, Jan; Szököl, Juraj; Ulbrich, P.; Nešvera, Jan; Pačes, Václav; Vlček, Čestmír

    2014-01-01

    Roč. 2, č. 2 (2014) ISSN 2169-8287 R&D Projects: GA ČR GA13-28283S; GA MŠk 2B08062 Institutional support: RVO:68378050 ; RVO:61388971 Keywords : Rhodococcus erythropolis * genome sequence Subject RIV: EB - Genetics ; Molecular Biology

  13. The degradation of wheat straw lignin

    Science.gov (United States)

    Liang, Jiaqi

    2017-03-01

    Lignin is a kind of formed by polymerization of aromatic alcohol, prices are lower and sources of renewable resources. Using lignin as raw material, through the push to resolve together preparation phenolic high value-added fine chemicals alkanes and aromatic hydrocarbons, such as the high grade biofuels, can partly replace fossil fuels as raw material to the production process, biomass resources is an important part of the comprehensive utilization of effective components. In lignin push solve clustering method, catalytic hydrogenolysis can directly to the lignin into liquid fuels, low oxygen content in the use of biofuels shows great potential. In this paper, through the optimization of the reaction time, reaction temperature, catalyst type and solvent type, dosage of catalyst, etc factors, determines the alcoholysis - hydrogen solution two-step degradation of lignin, the optimal process conditions: lignin alcoholysis under 50% methanol and NaOH catalyst in the solution, the lignin in methanol solution and 50% hydrogen solution under the Pd/C catalyst. In this process, the degradation of lignin yield can reach 42%.

  14. Anaerobic benzene degradation by Gram-positive sulfate-reducing bacteria.

    Science.gov (United States)

    Abu Laban, Nidal; Selesi, Drazenka; Jobelius, Carsten; Meckenstock, Rainer U

    2009-06-01

    Despite its high chemical stability, benzene is known to be biodegradable with various electron acceptors under anaerobic conditions. However, our understanding of the initial activation reaction and the responsible prokaryotes is limited. In the present study, we enriched a bacterial culture that oxidizes benzene to carbon dioxide under sulfate-reducing conditions. Community analysis using terminal restriction fragment length polymorphism, 16S rRNA gene sequencing and FISH revealed 95% dominance of one phylotype that is affiliated to the Gram-positive bacterial genus Pelotomaculum showing that sulfate-reducing Gram-positive bacteria are involved in anaerobic benzene degradation. In order to get indications of the initial activation mechanism, we tested the substrate utilization, performed cometabolism tests and screened for putative metabolites. Phenol, toluene, and benzoate could not be utilized as alternative carbon sources by the benzene-degrading culture. Cometabolic degradation experiments resulted in retarded rates of benzene degradation in the presence of phenol whereas toluene had no effect on benzene metabolism. Phenol, 2-hydroxybenzoate, 4-hydroxybenzoate, and benzoate were identified as putative metabolites in the enrichment culture. However, hydroxylated aromatics were shown to be formed abiotically. Thus, the finding of benzoate as an intermediate compound supports a direct carboxylation of benzene as the initial activation mechanism but additional reactions leading to its formation cannot be excluded definitely.

  15. Biological, ecological and agronomic significance of plant phenolic ...

    African Journals Online (AJOL)

    Phenolics are low molecular compounds ubiquitous in all tissues of higher plants with great significance in plant development. Our understanding of some phenolic compounds in the last few decades has greatly improved. However, their biological, ecological and agronomical significance in the rhizosphere of most ...

  16. Phenolic Content, and Antioxidant and Antimicrobial Activities of ...

    African Journals Online (AJOL)

    Erah

    Methods: The content of total phenols, flavonoids and anthocyanins of the alcohol, hydroalcohol and aqueous extracts of ... Keywords: Crataegus oxyacantha L.; Natural phenolic compounds; Antioxidant and antimicrobial activity, Southeast Serbia. ..... Antioxidant activities of Sechium edule (Jacq.) Swart extracts, Food ...

  17. 21 CFR 177.2410 - Phenolic resins in molded articles.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Phenolic resins in molded articles. 177.2410... as Components of Articles Intended for Repeated Use § 177.2410 Phenolic resins in molded articles... articles intended for repeated use in contact with nonacid food (pH above 5.0), in accordance with the...

  18. Phenolic acid changes during Orobanche parasitism on faba bean ...

    African Journals Online (AJOL)

    The present work is intended to provide further information on broomrape parasitism based on phenolic acid changes in either the host plant(s) or in each of the host and the parasite in the host-parasite system. Detection of phenolic acids was carried out using high performance liquid chromatography (HPLC) in the host ...

  19. Antioxidants and phenolic secretion in sugarcane genotypes shoot culture

    Science.gov (United States)

    The secretion of phenolic compounds is a major limitation for sugarcane in vitro culture, causing a loss of regenerative capacity and subsequent cell death. In this study, micropropagation and phenolic secretion of four Saccharum genotypes in the presence of different antioxidants were evaluated. As...

  20. Anti-cancer and antioxidant properties of phenolics isolated from ...

    African Journals Online (AJOL)

    Purpose: To investigate the antioxidant and anticancer activities of phenolics from the leaf extract of Toona sinensis (TS). Methods: Acetone leaf extract of TS was screened for total phenolic and flavanoid contents, and the flanonoids were subjected to high performance liquid chromatographic (HPLC) analysis. Antioxidant ...