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Unusual Catalytic Effect of Fe3+ on 2,4-dichlorophenoxyacetic Acid Degradation by Radio Frequency Discharge in Aqueous Solution. WATER 2022. [DOI: 10.3390/w14111719] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/07/2022]
Abstract
2,4-dichlorophenoxyacetic acid (2,4-D) is a widely used herbicide for controlling broad-leaved weeds. The development of an efficient process for treating the refractory 2,4-D wastewater is necessary. In this study, liquid-phase degradation of 2,4-D induced by radio frequency discharge (RFD) was studied. Experimental results showed that the degradation was more effective in acidic than in neutral or alkaline solutions. During the degradation, a large amount of hydrogen peroxide (H2O2, 1.2 mM/min, almost equal to that without 2,4-D) was simultaneously produced, and catalytic effects of both ferric (Fe3+) and ferrous (Fe2+) ions on the degradation were examined and compared. It was found that 2,4-D degraded more rapidly in the case of Fe3+ than the that of Fe2+. Such a scenario is explained that Fe3+ was successively reduced to Fe2+ by the atomic hydrogen (•H) and •OH-adducts of 2,4-D resulting from RFD, which in turn catalyzed the H2O2 to form more •OH radicals through Fenton’s reaction, indicating that Fe3+ not only accelerates the degradation rate but also increases the amount of •OH available for 2,4-D degradation by suppressing the back reaction between the •H and •OH. 2,4-dichlorophenol, 4,6-dichlororesorcinol, 2-hydroxy-4-chloro- and 2-chloro-4-hydroxy- phenoxyacetic acids, hydroxylated 2,4-Ds, and carboxylic acids (glycolic, formic and oxalic) were identified as the byproducts. Energy yields of RFD have been compared with those of other nonthermal plasma processes.
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2
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Fast Aqueous Biodegradation of Highly-Volatile Organic Compounds in a Novel Anaerobic Reaction Setup. ENVIRONMENTS 2018. [DOI: 10.3390/environments5110115] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The present work explores the biodegradation of some emerging pollutants (EPs) in an anaerobic slowly-agitated up-flow packed-bed reactor (USPBR) filled with biological activated carbon (BAC). Chlorobenzene (CB) and 2,4-dichlorophenoxyacetic acid (2,4-D) were selected as volatile organic compounds (VOC) and major constituents of many pesticides. Experiments carried out in continuous operation showed that bioconversion up to 90% was achieved for CB and 2,4-D, at space times below 0.6 h and 1.2 h, respectively, at ambient temperature. Overall, removal rates of 0.89 g L−1 d−1 and 0.46 g L−1 d−1 were obtained for CB and 2,4-D, respectively. These results revealed that the degradation of CB and 2,4-D in this anaerobic configuration of bioreactor is an efficient and fast process. The Michaelis–Menten model properly describes the degradation process for CB. Above initial concentrations of 100 mg L−1, 2,4-D presented a considerable inhibitory effect over the biofilm. For this reason, a substrate inhibition factor was included in the Michaelis–Menten equation; the expanded model presented a good fitting to the experimental data, regardless of the inlet concentration. Therefore, USPBR-BAC combination showed to be a highly efficient system for the biodegradation of such compounds.
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Cai J, Zhou M, Liu Y, Savall A, Groenen Serrano K. Indirect electrochemical oxidation of 2,4-dichlorophenoxyacetic acid using electrochemically-generated persulfate. CHEMOSPHERE 2018; 204:163-169. [PMID: 29655109 DOI: 10.1016/j.chemosphere.2018.04.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 03/29/2018] [Accepted: 04/01/2018] [Indexed: 06/08/2023]
Abstract
This research investigated persulfate electrosynthesis using a boron-doped diamond anode and a chemical reaction of persulfate in its activated form with an herbicide, 2,4-Dichlorophenoxyacetic acid (2,4-D). The first part of this research is dedicated to the influence of the applied current density on the electrosynthesis of persulfate. The first part shows that for a 2 M sulfuric acid, the current efficiency reached 96% for 5 mA/cm2 and dropped to 52% for a higher current density (100 mA cm-2). This fall cannot be explained by mass transfer limitations: an increase in temperature (from 9 to 30 °C) during electrolysis leads to the decomposition of 23% of the persulfate. The second part of this research shows that a quasi-complete degradation of the target herbicide can be reached under controlled operating conditions: (i) a high ratio of initial concentrations [Persulfate]/[2,4-D], (ii) a minimum temperature of 60 °C that produces sulfate radicals by heat decomposition of persulfate, and (iii) a sufficient contact time between reactants is required under dynamic conditions.
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Affiliation(s)
- Jingju Cai
- Key Laboratory of Pollution Process and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Urban Ecology Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Minghua Zhou
- Key Laboratory of Pollution Process and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Urban Ecology Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China.
| | - Ye Liu
- Laboratoire de Génie Chimique, CNRS, INPT, UPS, Université de Toulouse, 118 Route de Narbonne, F-31062, Toulouse, France
| | - André Savall
- Laboratoire de Génie Chimique, CNRS, INPT, UPS, Université de Toulouse, 118 Route de Narbonne, F-31062, Toulouse, France
| | - Karine Groenen Serrano
- Laboratoire de Génie Chimique, CNRS, INPT, UPS, Université de Toulouse, 118 Route de Narbonne, F-31062, Toulouse, France.
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D'Angelo A, Tedesco M, Cipollina A, Galia A, Micale G, Scialdone O. Reverse electrodialysis performed at pilot plant scale: Evaluation of redox processes and simultaneous generation of electric energy and treatment of wastewater. WATER RESEARCH 2017; 125:123-131. [PMID: 28843152 DOI: 10.1016/j.watres.2017.08.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 07/24/2017] [Accepted: 08/03/2017] [Indexed: 06/07/2023]
Abstract
This paper describes the experimental campaign carried out with a reverse electrodialysis (RED) demonstration plant (Marsala, Italy) with the main aims of: (i) evaluating the effect of various operating parameters, including the redox processes, on the system performances; (ii) using the plant for the simultaneous generation of electric energy and treatment of wastewater. The prototype (44 × 44 cm2, 500 cell pairs) was tested using both real (brackish water and brine) and artificial solutions. Tests with two different electrode rinse solutions (with or without iron redox couples) were performed. In agreement with the data obtained in the laboratory, the presence of iron ions contributes positively to the power production. The effect of flow rates in the electrode and saline compartments, as well as aging of the electrode rinse solution was also investigated. The possibility to remove an organic pollutant (the azoic dye Acid Orange 7) from the electrode solution was tested, obtaining a very fast and total removal of the pollutant. This experimental campaign represents the first demonstration in a real environment of the abilities of a RED plant to treat wastewater, thus giving useful indications for the spreading of RED technology in the near future.
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Affiliation(s)
- Adriana D'Angelo
- Dipartimento dell'Innovazione Industriale e Digitale, Ingegneria Chimica, Gestionale, Informatica, Meccanica, Universitá di Palermo (UNIPA), Viale delle Scienze Ed.6, 90128 Palermo, Italy
| | - Michele Tedesco
- Dipartimento dell'Innovazione Industriale e Digitale, Ingegneria Chimica, Gestionale, Informatica, Meccanica, Universitá di Palermo (UNIPA), Viale delle Scienze Ed.6, 90128 Palermo, Italy; Wetsus, European Centre of Excellence for Sustainable Water Technology, Oostergoweg 9, 8911 MA Leeuwarden, The Netherlands
| | - Andrea Cipollina
- Dipartimento dell'Innovazione Industriale e Digitale, Ingegneria Chimica, Gestionale, Informatica, Meccanica, Universitá di Palermo (UNIPA), Viale delle Scienze Ed.6, 90128 Palermo, Italy
| | - Alessandro Galia
- Dipartimento dell'Innovazione Industriale e Digitale, Ingegneria Chimica, Gestionale, Informatica, Meccanica, Universitá di Palermo (UNIPA), Viale delle Scienze Ed.6, 90128 Palermo, Italy
| | - Giorgio Micale
- Dipartimento dell'Innovazione Industriale e Digitale, Ingegneria Chimica, Gestionale, Informatica, Meccanica, Universitá di Palermo (UNIPA), Viale delle Scienze Ed.6, 90128 Palermo, Italy
| | - Onofrio Scialdone
- Dipartimento dell'Innovazione Industriale e Digitale, Ingegneria Chimica, Gestionale, Informatica, Meccanica, Universitá di Palermo (UNIPA), Viale delle Scienze Ed.6, 90128 Palermo, Italy.
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5
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Pitoi MM, Patterson BM, Furness AJ, Bastow TP, McKinley AJ. Fate of N-nitrosomorpholine in an anaerobic aquifer used for managed aquifer recharge: a column study. WATER RESEARCH 2011; 45:2550-2560. [PMID: 21396674 DOI: 10.1016/j.watres.2011.02.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2010] [Revised: 02/04/2011] [Accepted: 02/12/2011] [Indexed: 05/30/2023]
Abstract
The fate of N-nitrosomorpholine (NMOR) was evaluated at microgram and nanogram per litre concentrations. Experiments were undertaken to simulate the passage of groundwater contaminants through a deep anaerobic pyritic aquifer system, as part of a managed aquifer recharge (MAR) strategy. Sorption studies demonstrated the high mobility of NMOR in the Leederville aquifer system, with retardation coefficients between 1.2 and 1.6. Degradation studies from a 351 day column experiment and a 506 day stop-flow column experiment showed an anaerobic biologically induced reductive degradation process which followed first order kinetics. A biological lag-time of less than 3 months and a transient accumulation of morpholine (MOR) were also noted during the degradation. Comparable half-life degradation rates of 40-45 days were observed over three orders of magnitude in concentration (200 ng L(-1) to 650 μg L(-1)). An inhibitory effect on microorganism responsible to the biodegradation of NMOR at 650 μg L(-1) or a threshold effect at 200 ng L(-1) was not observed during these experiments.
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Affiliation(s)
- M M Pitoi
- CSIRO Land and Water, Private Bag 5, Wembley, WA 6913, Australia
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6
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Tong SP, Shi R, Zhang H, Ma CA. Kinetics of Fe(3)O(4)-CoO/Al(2)O(3) catalytic ozonation of the herbicide 2-(2,4-dichlorophenoxy) propionic acid. JOURNAL OF HAZARDOUS MATERIALS 2011; 185:162-167. [PMID: 20926187 DOI: 10.1016/j.jhazmat.2010.09.013] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2009] [Revised: 09/06/2010] [Accepted: 09/07/2010] [Indexed: 05/30/2023]
Abstract
The presence of Fe(3)O(4)-CoO/Al(2)O(3) can improve degradation efficiency significantly during the ozonation of the herbicide 2-(2,4-dichlorophenoxy) propionic acid (2,4-DP). The main factors affecting degradation efficiency, such as pH, the catalyst concentration and addition of the scavenger, were investigated. The kinetics of the catalytic ozonation are also discussed. The results indicate that two factors, the oxidation after adsorption of 2,4-DP and the oxidation of hydroxyl radicals (OH), lead to a great enhancement in ozonation efficiency during the catalytic ozonation of 2,4-DP in the presence of Fe(3)O(4)-CoO/Al(2)O(3), in which the oxidation of the OH plays an important role. Under controlled conditions, the apparent reaction rate constants for the degradation of 2,4-DP were determined to be 2.567 × 10(-4)s(-1) for O(3) and 1.840 × 10(-3)s(-1) for O(3)/Fe(3)O(4)-CoO/Al(2)O(3). The results from the analysis of the reaction kinetics using the relative method showed that O(3)/Fe(3)O(4)-CoO/Al(2)O(3) possessed a larger R(ct) (R(ct) is defined as the ratio of the ·OH exposure to the O(3) exposure, R(ct) = ∫C(t)(OH) dt/C(t)O(3)dt) than O(3), indicating that O(3)/Fe(3)O(4)-CoO/Al(2)O(3) produced more hydroxyl radicals.
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Affiliation(s)
- Shao-Ping Tong
- College of Chemical Engineering and Materials Science, State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, Zhejiang University of Technology, Hangzhou 310032, China.
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Junker T, Paatzsch C, Knacker T. A water-sediment screening tool for measuring biodegradation of organic chemicals. THE SCIENCE OF THE TOTAL ENVIRONMENT 2010; 408:3803-3810. [PMID: 19945141 DOI: 10.1016/j.scitotenv.2009.11.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2009] [Revised: 11/05/2009] [Accepted: 11/05/2009] [Indexed: 05/28/2023]
Abstract
A water-sediment screening tool (WSST) was developed based on OECD guideline 301 C (MITI I; Ministry of International Trade and Industry, Japan) to generate biodegradation data. The WSST and experimental procedures were tested and validated using aniline (CAS No. 62-53-3) and benzoic acid (CAS No. 65-85-0) as reference substances. In the presence of sediment components a higher endogenous respiration rate in the control vessels without test substance was measured compared to the water-only MITI test system, particularly due to organic constituents. However, it could be demonstrated that a distinct biodegradation in the presence of sediment can be determined and that there is no influence of the sediment pre-treatment on the biological oxygen demand in the WSST. Experiments resulted in biodegradation rates >60% after approximately six days for both compounds. However, degradation of benzoic acid resulted in a shorter lag-phase and a higher degree of degradation compared to aniline. Differences in results between the MITI test system and the WSST observed for aniline can be explained by adsorption to constituents of the sediment and assimilation by activated sludge. In comparison with literature data the results obtained for aniline in the MITI test system and the WSST showed reproducibility and were within the expected range. In conclusion, the WSST is a suitable screening tool to determine kinetic biodegradation data required to predict the biodegradation behaviour of organic chemicals in water-sediment systems and the data might be used to improve quantitative structure-property relationships (QSPRs).
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Affiliation(s)
- Thomas Junker
- ECT Oekotoxikologie GmbH, Boettgerstrasse 2-14, D-65439 Floersheim, Germany.
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8
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Tong S, Shi R, Zhang H, Ma C. Catalytic performance of Fe3O4-CoO/Al2O3 catalyst in ozonation of 2-(2,4-dichlorophenoxy)propionic acid, nitrobenzene and oxalic acid in water. J Environ Sci (China) 2010; 22:1623-1628. [PMID: 21235195 DOI: 10.1016/s1001-0742(09)60298-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Fe3O4-CoO/Al2O3 catalyst was prepared by incipient wetness impregnation using Fe(NO3)3 x 9H2O and Co(NO3)2 x 6H2O as the precursors, and its catalytic performance was investigated in ozonation of 2-(2,4-dichlorophenoxy)propionic acid (2,4-DP), nitrobenzene and oxalic acid. The experimental results indicated that Fe3O4-CoO/Al2O3 catalyst enabled an interesting improvement of ozonation efficiency during the degradation of each organic pollutant, and the Fe3O4-CoO/Al2O3 catalytic ozonation system followed a radical-type mechanism. The kinetics of ozonation alone and Fe3O4-CoO/Al2O3 catalytic ozonation of three organic pollutants in aqueous solution were discussed under the mere consideration of direct ozone reaction and OH radical reaction to well investigate its performance. In the catalytic ozonation of 2,4-DP, the apparent reaction rate constants (k) were determined to be 1.456 x 10(-2) min(-1) for ozonation alone and 4.740 x 10(-2) min(-1) for O3/Fe3O4-CoO/Al203. And O3/Fe3O4-CoO/Al2O3 had a larger R(ct) (6.614 x 10(-9)) calculated by the relative method than O3 did (1.800 x 10(-9)), showing O3/Fe3O4-CoO/Al2O3 generated more hydroxyl radical. Similar results were also obtained in the catalytic ozonation of nitrobenzene and oxalic acid. The above results demonstrated that the catalytic performance of Fe3O4-CoO/Al2O3 in ozonation of studied organic substance was universal to a certain degree.
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Affiliation(s)
- Shaoping Tong
- College of Chemical Engineering and Materials Science, State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, Zhejiang University of Technology, Hangzhou 310032, China.
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Huang Y, Liu X, Fang Y, Wang Q, Lau K. Degradation of 2, 4-D acid using Mn2+ as catalyst under UV irradiation. ACTA ACUST UNITED AC 2009. [DOI: 10.1007/s11859-009-0314-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Zhao BX, Li XZ, Wang P. 2,4-Dichlorophenol Degradation by an Integrated Process: Photoelectrocatalytic Oxidation and E-Fenton Oxidation. Photochem Photobiol 2007; 83:642-6. [PMID: 17132072 DOI: 10.1562/2006-09-05-ra-1030] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A new reactor system was designed for an integrated process involving photoelectrocatalytic oxidation (PECO) and electro-Fenton (E-Fenton) oxidation. Its efficiency was evaluated in terms of 2,4-dichlorophenol (2,4-DCP) degradation in aqueous solution. In this process, a TiO2 electrode and an iron (Fe) electrode were used as anodes in parallel, while graphite felt (GF) was used as a cathode. When an electrical current is applied between the anodes and the cathode, the iron anode can release Fe2+ and the GF cathode can generate H2O2 continuously in the reaction solution. Under UV-A illumination, while a H2O2-assisted PECO reaction occurs on the surface of the TiO2 photo anode, an E-Fenton reaction takes place in the solution. The experimental results demonstrated that 2,4-DCP degradation in aqueous solution was greatly enhanced because of the interaction between the two types of reactions. Moreover, the effect of pH as an important factor was investigated. It was found that the combined reaction becomes less pH sensitive than the typical E-Fenton reaction and may be suitable for application in a wide pH range.
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Affiliation(s)
- B X Zhao
- Research Center for Green Chemistry and Technology, School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China
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11
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Jankowska A, Biesaga M, Drzewicz P, Trojanowicz M, Pyrzyńska K. Chromatographic separation of chlorophenoxy acid herbicides and their radiolytic degradation products in water samples. WATER RESEARCH 2004; 38:3259-3264. [PMID: 15276742 DOI: 10.1016/j.watres.2004.03.032] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2003] [Revised: 02/25/2004] [Accepted: 03/08/2004] [Indexed: 05/24/2023]
Abstract
HPLC procedure for simultaneous determination of chlorophenoxy acid herbicides and their radiolytic degradation products in waters is described with the use of octadecylsilica column and spectrophotometric detection at 280 nm. The satisfactory separation was achieved with a mobile phase of pH 2.5 consisting of 43.7 mM acetic acid with 40% (v/v) acetonitrile. Limit of detection values for herbicides and phenol derivatives were in the range of 19-41 microg/l and 10-60 microg/l, respectively. The developed method was applied for monitoring the effectiveness of radiolytic degradation of herbicides. Studies of products of gamma-radiolysis of 2,4-dichlorophenol have shown that the efficiency of this process is affected by the presence of naturally occurring scavengers of gamma-radiation such as carbonates or nitrates.
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Affiliation(s)
- A Jankowska
- Department of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland
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Decomposition of 2,4-dichlorophenoxyacetic acid by ozonation, ionizing radiation as well as ozonation combined with ionizing radiation. Radiat Phys Chem Oxf Engl 1993 2004. [DOI: 10.1016/s0969-806x(03)00471-7] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Campos SXD, Sanches SM, Falone SZ, Vieira EM. Influência da taxa de dose na degradação do herbicida ácido diclorofenóxiacético (2,4-d) por meio da radiação gama do cobalto-60. ECLÉTICA QUÍMICA 2004. [DOI: 10.1590/s0100-46702004000100005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Métodos convencionais de descontaminação ambiental, algumas vezes apenas transferem esses resíduos de um lugar para outro. Esse estudo tem como objetivo checar a influência de diferentes taxas de doses de radiação gama do cobalto-60 na degradação do herbicida 2,4-D, em água e metanol. Os resultados mostraram que o 2,4-D, em água, foi totalmente degradado em uma dose de 30 kGy, utilizando-se taxa de dose de 2,7 kGy h-1 e 20 kGy com uma taxa de dose de 5- 60 kGy h-1. Para o metanol, a total degradação do 2,4-D ocorreu com uma dose de 150 kGy e taxa de dose de 2,7 kGy h-1 e 100 kGy utilizando-se taxa de dose de 5- 60 kGy h-1. Assim conclui-se que a degradação do herbicida 2,4-D é dependente da dose e da taxa de dose de radiação.O valor radiolítico da degradação do 2,4-D foi calculado.
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Campos SX, Vieira EM, Cordeiro PJ, Rodrigues-Fo E, Murgu M. Degradation of the herbicide 2, 4-dichlorophenoxyacetic acid (2,4-D) dimethylamine salt by gamma radiation from cobalt-60 in aqueous solution containing humic acid. Radiat Phys Chem Oxf Engl 1993 2003. [DOI: 10.1016/s0969-806x(03)00366-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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15
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Zona R, Solar S. Oxidation of 2,4-dichlorophenoxyacetic acid by ionizing radiation: degradation, detoxification and mineralization. Radiat Phys Chem Oxf Engl 1993 2003. [DOI: 10.1016/s0969-806x(02)00330-4] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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16
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Chu W, Ching MH. Modeling the ozonation of 2,4-dichlorophoxyacetic acid through a kinetic approach. WATER RESEARCH 2003; 37:39-46. [PMID: 12465786 DOI: 10.1016/s0043-1354(02)00250-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The ozonation of herbicide 2,4-dichlorophoxyacetic acid (2,4-D) was studied and modeled at different initial pH levels and initial concentrations. The degradation rate of 2,4-D was found to increase with the initial pH level and decrease with initial 2,4-D concentration. A two-stage ozonation of 2,4-D was observed, in which the initial stage of ozonation was slightly faster than the second stage due to the higher initial (saturated) ozone concentration; under these circumstances, the direct molecular ozone oxidation was likely to predominate. At the second stage, the indirect radical oxidation became more significant in determining the overall 2,4-D oxidation, and the reaction was more pH-dependent. A mathematic model associated with the analytical solutions consisting of direct and indirect oxidations contributed by the molecular ozone and free radical is proposed. The proposed model is capable of predicting the decay of 2,4-D quantitatively by ozonation at different initial pH levels and initial 2,4-D concentrations.
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Affiliation(s)
- W Chu
- Department of Civil and Structural Engineering, Research Centre for Urban Environmental Technology and Management, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
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Zona R, Solar S, Gehringer P. Degradation of 2,4-dichlorophenoxyacetic acid by ionizing radiation: influence of oxygen concentration. WATER RESEARCH 2002; 36:1369-1374. [PMID: 11902792 DOI: 10.1016/s0043-1354(01)00323-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Ionizing radiation has been proved as a promising method for the degradation of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D). The gamma-radiolytic decomposition and chloride formation follows an apparent first order kinetic, kde/kCl = 3. For complete removal of 500 microM 2,4-D, a dose of 4 kGy is required. Phenolic intermediates (2,4-dichlorophenol, the isomers 2-chloro-4-hydroxy- and 4-chloro-2-hydroxy phenoxyacetic acid and three hydroxylation products of 2,4-D) are formed. Using oxygen saturation during irradiation, they are removed again with a dose of 4 kGy. For the formation of the main organic product acetic acid a reaction mechanism is discussed. Oxygen concentration enhances strongly fragmentation and mineralization. A reduction of 36% TOC could be achieved.
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Affiliation(s)
- R Zona
- Institute for Theoretical Chemistry and Structural Biology, University of Vienna, Austria
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18
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Roch F, Védy JC. Modulation of metabolic activity prevents degradation of sorbed toluene. CHEMOSPHERE 1999; 38:1797-1810. [PMID: 10101849 DOI: 10.1016/s0045-6535(98)00395-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The factors affecting the ability of a bacterial species to degrade different amounts of toluene (8.5 to 217 mg/g) sorbed to granular activated carbon (GAC), in an aqueous solution of mineral salts, were investigated. After 144 days the amounts of toluene remaining on one type of GAC ranged from 7.5 to 9.5 mg/g, and the aqueous concentrations of toluene ranged from 2 to 7 micrograms/L. Neither bacterial death nor an inhibition by accumulating by-products could explain why the remaining toluene had not been degraded. However, at these low concentrations of toluene, and probably because of cell starvation, bacteria were observed to be more than 100-times less efficient to degrade toluene than at high concentrations. We propose that this low degradation ability is responsible for the presence of residual toluene on the GAC, and that this mechanism may contribute to the persistence of low concentrations of sorbed pollutants in the environment.
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Affiliation(s)
- F Roch
- Département de Génie Rural, Swiss Federal Institute of Technology, Lausanne, Switzerland
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Fomsgaard IS, Johannesen H, Pitty J, Rugama R. Degradation of14c‐maneb in sediment from a Nicaraguan estuary. ACTA ACUST UNITED AC 1998. [DOI: 10.1080/00207239808711176] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Fomsgaard IS. Modelling the mineralization kinetics for low concentrations of pesticides in surface and subsurface soil. Ecol Modell 1997. [DOI: 10.1016/s0304-3800(97)01982-0] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Providenti MA, Lee H, Trevors JT. Selected factors limiting the microbial degradation of recalcitrant compounds. ACTA ACUST UNITED AC 1993. [DOI: 10.1007/bf01569669] [Citation(s) in RCA: 84] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Lewis DL, Gattie DK. Predicting chemical concentration effects on transformation rates of dissolved organics by complex microbial assemblages. Ecol Modell 1991. [DOI: 10.1016/0304-3800(91)90062-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Neilson AH. The biodegradation of halogenated organic compounds. THE JOURNAL OF APPLIED BACTERIOLOGY 1990; 69:445-70. [PMID: 2292512 DOI: 10.1111/j.1365-2672.1990.tb01536.x] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- A H Neilson
- Swedish Environmental Research Institute, Stockholm
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Stenström J. Kinetics of decomposition of 2,4-dichlorophenoxyacetic acid byAlcaligenes eutrophus JMP134 and in soil. ACTA ACUST UNITED AC 1989. [DOI: 10.1002/tox.2540040402] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Izaguirre G, Wolfe RL, Means EG. Degradation of 2-Methylisoborneol by Aquatic Bacteria. Appl Environ Microbiol 1988; 54:2424-31. [PMID: 16347753 PMCID: PMC204277 DOI: 10.1128/aem.54.10.2424-2431.1988] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
2-Methylisoborneol (MIB) is a musty- or muddy-smelling compound which occurs in some natural waters and which is difficult to remove by conventional water treatment methods. Bacterial degradation of MIB was examined in batch culture experiments. Cultures able to metabolize MIB were enriched in a mineral salts medium supplemented with milligram-per-liter levels of the compound and were inoculated with water and sediment samples from reservoirs where MIB is seasonally produced. Bacteria from degrading cultures were isolated on R2A agar and identified as predominantly
Pseudomonas
spp. Degradation occurred only in cultures consisting of three or more different bacteria. MIB supported growth as the sole added carbon source at 1 to 6.7 mg/liter. MIB was also degraded at microgram-per-liter levels in sterile filtered lake water inoculated with washed bacteria and in synthetic medium supplemented with various sugars or acetate. Complete degradation of MIB took from 5 days to more than 2 weeks. Enrichment with isoborneol, a structural analog of MIB, failed as a preenrichment for MIB degraders. Isoborneol at 20 to 40 mg/liter readily supported bacterial growth, whereas MIB at 12 to 20 mg/liter took months to degrade. The relative recalcitrance of MIB compared with isoborneol may be a result of the additional methyl group in MIB.
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Affiliation(s)
- G Izaguirre
- Water Quality Division, Metropolitan Water District of Southern California, La Verne, California 91750
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Jones SH, Alexander M. Phosphorus enhancement of mineralization of low concentrations ofp-nitrophenol byFlavobacteriumsp. in lake water. FEMS Microbiol Lett 1988. [DOI: 10.1111/j.1574-6968.1988.tb02582.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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