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Zhao H, Wang S, Chenggang L, Tang Y, Pan Y. Theoretical study on degradation of polymethyl substituted benzenes by OH radicals in the atmosphere. CHEMOSPHERE 2024; 352:141243. [PMID: 38246501 DOI: 10.1016/j.chemosphere.2024.141243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 01/15/2024] [Accepted: 01/16/2024] [Indexed: 01/23/2024]
Abstract
As volatile organic compounds (VOCs), pentamethylbenzene (5-PeMB) and hexamethylbenzene (6-HeMB) are found widely in petroleum and coal tar. Through combustion and industrial generation entering into the atmosphere, they can produce photochemical smog and secondary organic aerosols (SOA) to endanger human health and ecoenvironment eventually. In order to reveal their environmental chemistry, the OH-initiated degradation mechanisms of 5-PeMB and 6-HeMB were studied based on density functional theory (DFT). Result showed that addition pathways were the most favorable with energy barriers of 20.7 and 25.3 kJ/mol, respectively, in the two reactions. The degradation rate constants at 298 K were calculated to be 2.69 × 10-10 and 1.28 × 10-10 cm3 molecule-1 ·s-1, coinciding with the available experimental values. In the presence of OH radicals, the atmospheric lifetimes were estimated to be 2.17 and 2.78 h, respectively, for 5-PeMB and 6-HeMB. According to the quantitative structure-activity relationship (QSAR) model, the toxicity during the degradation process is decreased to fish, daphnia, and green algae.
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Affiliation(s)
- Hui Zhao
- School of Environmental and Municipal Engineering, Qingdao University of Technology, Fushun Road 11, Qingdao, Shandong, 266033, PR China
| | - Shuangjun Wang
- School of Environmental and Municipal Engineering, Qingdao University of Technology, Fushun Road 11, Qingdao, Shandong, 266033, PR China
| | - Lu Chenggang
- School of Environmental and Municipal Engineering, Qingdao University of Technology, Fushun Road 11, Qingdao, Shandong, 266033, PR China
| | - Yizhen Tang
- School of Environmental and Municipal Engineering, Qingdao University of Technology, Fushun Road 11, Qingdao, Shandong, 266033, PR China.
| | - Yaru Pan
- Tonghua Normal Collage, Yucai Roads 950, Tonghua, Jilin, 134000, PR China
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2
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Gawel A, Sühnholz S, Georgi A, Kopinke FD, Mackenzie K. Fe-zeolites for the adsorption and oxidative degradation of nitroaromatic compounds in water. JOURNAL OF HAZARDOUS MATERIALS 2023; 459:132125. [PMID: 37515994 DOI: 10.1016/j.jhazmat.2023.132125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 07/20/2023] [Accepted: 07/21/2023] [Indexed: 07/31/2023]
Abstract
Nitroaromatic compounds (NACs) are prominent explosives. In this context, these toxic substances were released into the environment and cause long-lasting groundwater contamination. In preparation of a possible in-situ remediation, colloidal Fe-zeolites were investigated for their capabilities as adsorbents and oxidation catalysts. It was shown that the Fe-zeolites FeBEA35 and FeFAU55 are potent inorganic adsorbents for NACs and simultaneously capable of activating H2O2 as Fenton-like oxidation catalysts. Adsorption isotherms of 15 NACs on both zeolites were measured to evaluate the option of coupling adsorptive contaminant enrichment with oxidative degradation. The faujasite-type zeolite FeFAU55 showed a distinct S-type adsorption behaviour and reached significantly higher NAC loadings of > 20 wt%. For FeBEA35, L-type adsorption isotherms and maximum loadings qmax of about 4 wt% were obtained. Degradation of all NACs, monitored by nitrate formation, was observed. Apparent rate constants of the NACs with hydroxyl radicals in a homogeneous, stoichiometric Fenton reaction were related to the heterogeneous system to examine the role of adsorption on the oxidative degradation. Beneficial influence of the adsorption on the oxidation rates was identified. The results of this work open up promising prospects for future application of Fe-zeolites for the in-situ remediation of NAC-contaminated groundwater.
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Affiliation(s)
- Alina Gawel
- Evonik Operations GmbH, Process Technology & Engineering, Paul-Baumann-Str. 1, D-45772 Marl, Germany.
| | - Sarah Sühnholz
- Helmholtz-Center for Environmental Research - UFZ, Department of Environmental Engineering, Permoserstr. 15, D-04318 Leipzig, Germany; Intrapore GmbH, Katernberger Str. 107, D-45327 Essen, Germany
| | - Anett Georgi
- Helmholtz-Center for Environmental Research - UFZ, Department of Environmental Engineering, Permoserstr. 15, D-04318 Leipzig, Germany
| | - Frank-Dieter Kopinke
- Helmholtz-Center for Environmental Research - UFZ, Department of Environmental Engineering, Permoserstr. 15, D-04318 Leipzig, Germany
| | - Katrin Mackenzie
- Helmholtz-Center for Environmental Research - UFZ, Department of Environmental Engineering, Permoserstr. 15, D-04318 Leipzig, Germany
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3
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Costante MR, García Einschlag FS. Assessment of key processes that govern the degradation of mixtures in photo-Fenton systems. J Photochem Photobiol A Chem 2022. [DOI: 10.1016/j.jphotochem.2022.114096] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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4
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Rodríguez-Córdoba W, Gutiérrez-Arzaluz L, Cortés-Guzmán F, Peon J. Excited state dynamics and photochemistry of nitroaromatic compounds. Chem Commun (Camb) 2021; 57:12218-12235. [PMID: 34735557 DOI: 10.1039/d1cc04999b] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Nitrated aromatic molecules have unique photoinduced channels. Due to the presence of oxygen-centered non-bonding orbitals, they can undergo sub-picosecond intersystem crossing showing one of the strongest couplings between the singlet and triplet manifolds among organic molecules. Several nitroaromatic compounds also have a distinctive nitric oxide photodissociation channel which occurs through a complex sequence of atom rearrangements and state changes. These remarkable processes have stimulated the attention of several research groups over the last few years who have applied modern femtosecond spectroscopies and new computational methods to these topics. Nitroaromatic molecules also have demonstrated their value as case-studies, where they can serve to understand the influence of torsional motions between the nitro substituent and the aromatic system in the conversions between states. In this contribution we highlight several of the recent results in this area. Due to the importance of the atmospheric photochemistry of nitrated compounds and their accumulating applications as nitric oxide release agents, continued research about the effects of the different state orderings, substitution patterns, and solvent effects is central to the development of future applications and for a better understanding of their environmental pathways. From this analysis, several pending issues are highlighted, which include the nature of the dominant singlet state involved in intersystem crossing, the role of the formation of charge-transfer states, the yield of the internal conversion channel to the electronic ground state, and a more generalized understanding of the sequence of steps which lead to nitric oxide dissociation.
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Affiliation(s)
- William Rodríguez-Córdoba
- Facultad de ciencias, Escuela de Física, Laboratorio de Fotónica y Optoelectrónica, Universidad Nacional de Colombia - Sede Medellín, Calle 59 A No. 63-20, A.A. 3840, Medellín, Colombia.
| | - Luis Gutiérrez-Arzaluz
- Division of Physical Sciences and Engineering (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia.
| | - Fernando Cortés-Guzmán
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, México, 04510 D.F., Mexico.
| | - Jorge Peon
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, México, 04510 D.F., Mexico.
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5
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UV/H2O2 oxidation of chloronitrobenzenes in waters revisited: Hydroxyl radical induced self-nitration. J Photochem Photobiol A Chem 2021. [DOI: 10.1016/j.jphotochem.2021.113162] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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6
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Jayababu S, Inbasekaran M, Narayanasamy S. Significantly improved solar photodegradation of water pollutant by new plate-like bismuth ferrite nanoparticles tuned by gelatin. INORG CHEM COMMUN 2021. [DOI: 10.1016/j.inoche.2020.108306] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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7
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Hasan I, Shekhar C, Alharbi W, Abu Khanjer M, Khan RA, Alsalme A. A Highly Efficient Ag Nanoparticle-Immobilized Alginate-g-Polyacrylonitrile Hybrid Photocatalyst for the Degradation of Nitrophenols. Polymers (Basel) 2020; 12:E3049. [PMID: 33352658 PMCID: PMC7766039 DOI: 10.3390/polym12123049] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 12/13/2020] [Accepted: 12/15/2020] [Indexed: 12/15/2022] Open
Abstract
Herein, we report PAN-g-Alg@Ag-based nanocatalysts synthesis via in situ oxidative free-radical polymerization of acrylonitrile (AN) using Alg@Ag nanoparticles (Alg@Ag NPs). Various analytical techniques, including FTIR, XRD, SEM, TEM, UV-Vis, and DSC, were employed to determine bonding interactions and chemical characteristics of the nanocatalyst. The optimized response surface methodology coupled central composite design (RSM-CCD) reaction conditions were a 35-min irradiation time in a 70-mg L-1 2,4-dinitrophenol (DNP) solution at pH of 4.68. Here, DNP degradation was 99.46% at a desirability of 1.00. The pseudo-first-order rate constant (K1) values were 0.047, 0.050, 0.054, 0.056, 0.059, and 0.064 min-1 with associated half-life (t1/2) values of 14.74, 13.86, 12.84, 12.38, 11.74, 10.82, and 10.04 min that corresponded to DNP concentrations of 10, 20, 30, 40, 50, 60, and 70 mg L-1, respectively, in the presence of PAN-g-Alg@Ag (0.03 g). The results indicate that the reaction followed the pseudo-first-order kinetic model with an R2 value of 0.99. The combined absorption properties of PAN and Alg@Ag NPs on copolymerization on the surface contributed more charge density to surface plasmon resonance (SPR) in a way to degrade more and more molecules of DNP together with preventing the recombination of electron and hole pairs within the photocatalytic process.
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Affiliation(s)
- Imran Hasan
- Environmental Research Laboratory, Department of Chemistry, Chandigarh University, Gharuan, Mohali 140301, Punjab, India; (I.H.); (C.S.)
| | - Charu Shekhar
- Environmental Research Laboratory, Department of Chemistry, Chandigarh University, Gharuan, Mohali 140301, Punjab, India; (I.H.); (C.S.)
| | - Walaa Alharbi
- Department of Chemistry, Faculty of Science, King Khalid University, P.O. Box-9004, Abha 62529, Saudi Arabia;
| | - Maymonah Abu Khanjer
- Department of Chemistry, College of Science, King Saud University, Riyadh 11451, Saudi Arabia; (M.A.K.); (R.A.K.)
| | - Rais Ahmad Khan
- Department of Chemistry, College of Science, King Saud University, Riyadh 11451, Saudi Arabia; (M.A.K.); (R.A.K.)
| | - Ali Alsalme
- Department of Chemistry, College of Science, King Saud University, Riyadh 11451, Saudi Arabia; (M.A.K.); (R.A.K.)
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8
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Ji Y, Shi Y, Yang Y, Yang P, Wang L, Lu J, Li J, Zhou L, Ferronato C, Chovelon JM. Rethinking sulfate radical-based oxidation of nitrophenols: Formation of toxic polynitrophenols, nitrated biphenyls and diphenyl ethers. JOURNAL OF HAZARDOUS MATERIALS 2019; 361:152-161. [PMID: 30179786 DOI: 10.1016/j.jhazmat.2018.08.083] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 08/07/2018] [Accepted: 08/24/2018] [Indexed: 06/08/2023]
Abstract
Sulfate radical (SO4-)-based oxidation of nitrophenols (NPs) have been widely studied; however, formation of potentially more toxic polynitroaromatic intermediates has been overlooked. In this contribution, we systematically investigated the degradation of four NPs by a SO4--based oxidation process. Degradation efficiency of NPs followed the order: 2-nitrophenol (2-NP) > 4-nitrophenol (4-NP) > 2,4-dinitrophenol (2,4-DNP) > 2,6-dinitrophenol (2,6-DNP). HPLC and LC-MS/MS analysis confirmed the formation of 2,4-DNP, 2,6-DNP and 2,4,6-trinitrophenol (2,4,6-TNP) during NPs transformation by SO4-, suggesting that both denitration and renitration processes occurred. Nitrogen dioxide radicals (NO2) and phenoxy radicals are responsible for the formation of polynitrophenols. Coupling products including nitrated biphenyls and diphenyl ethers were also detected, which were proposed to be formed by combinations of resonance-stabilized radicals. Electron spin density and charge density calculation showed that ortho C-ortho C and ortho C-phenolic O were the most likely combination ways responsible for coupling products formation. ECOSAR program predicted that polynitrated diphenyl ethers and biphenyls had higher ecotoxicological effects on aquatic species such as fish and daphnia. Therefore, the formation of toxic polynitroaromatic intermediates in SO4--based advanced oxidation processes should be scrutinized before this technology can be safely utilized for water and wastewater treatment.
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Affiliation(s)
- Yuefei Ji
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China.
| | - Yuanyuan Shi
- SHU-UTS SILC Business School, Shanghai, 201800, China
| | - Yan Yang
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Peizeng Yang
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Lu Wang
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Junhe Lu
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China.
| | - Jianhua Li
- Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China
| | - Lei Zhou
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, IRCELYON, F-69626, Villeurbanne, France
| | - Corinne Ferronato
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, IRCELYON, F-69626, Villeurbanne, France
| | - Jean-Marc Chovelon
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, IRCELYON, F-69626, Villeurbanne, France
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9
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Yang P, Luo S, Liu Y, Jiao W. Degradation of nitrobenzene wastewater in an acidic environment by Ti(IV)/H 2O 2/O 3 in a rotating packed bed. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:25060-25070. [PMID: 29936612 DOI: 10.1007/s11356-018-2551-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 06/13/2018] [Indexed: 06/08/2023]
Abstract
The rotating packed bed (RPB) as a continuous flow reactor performs very well in degradation of nitrobenzene wastewater. In this study, acidic nitrobenzene wastewater was degraded using ozone (O3) combined with hydrogen peroxide and titanium ions (Ti(IV)/H2O2/O3) or using only H2O2/O3 in a RPB. The degradation efficiency of nitrobenzene by Ti(IV)/H2O2/O3 is roughly 16.84% higher than that by H2O2/O3, and it reaches as high as 94.64% in 30 min at a H2O2/O3 molar ratio of 0.48. It is also found that the degradation efficiency of nitrobenzene is significantly affected by the high gravity factor, H2O2/O3 molar ratio, and Ti(IV) concentration, and it reaches a maximum at a high gravity factor of 40, a Ti(IV) concentration of 0.50 mmol/L, a pH of 4.0, a H2O2/O3 molar ratio of 0.48, a liquid flow rate of 120 L/h, and an initial nitrobenzene concentration of 1.22 mmol/L. Both direct ozonation and indirect ozonation are involved in the reaction of O3 with organic pollutants. The indirect ozonation due to the addition of different amounts of tert-butanol (·OH scavenger) in the system accounts for 84.31% of the degradation efficiency of nitrobenzene, indicating that the nitrobenzene is dominantly oxidized by ·OH generated in the RPB-Ti(IV)/H2O2/O3 process. Furthermore, the possible oxidative degradation mechanisms are also proposed to better understand the role of RPB in the removal of pollutants. Graphical abstract ᅟ.
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Affiliation(s)
- Peizhen Yang
- Shanxi Province Key Laboratory of Higee-Oriented Chemical Engineering, North University of China, Taiyuan, 030051, Shanxi, China
| | - Shuai Luo
- Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24061, USA
| | - Youzhi Liu
- Shanxi Province Key Laboratory of Higee-Oriented Chemical Engineering, North University of China, Taiyuan, 030051, Shanxi, China
| | - Weizhou Jiao
- Shanxi Province Key Laboratory of Higee-Oriented Chemical Engineering, North University of China, Taiyuan, 030051, Shanxi, China.
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10
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Zotesso JP, Cossich ES, Janeiro V, Tavares CRG. Treatment of hospital laundry wastewater by UV/H 2O 2 process. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2017; 24:6278-6287. [PMID: 27234839 DOI: 10.1007/s11356-016-6860-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Accepted: 05/09/2016] [Indexed: 05/15/2023]
Abstract
Hospitals consume a large volume of water to carry out their activities and, hence, generate a large volume of effluent that is commonly discharged into the local sewage system without any treatment. Among the various sectors of healthcare facilities, the laundry is responsible for the majority of water consumption and generates a highly complex effluent. Although several advanced oxidation processes (AOPs) are currently under investigation on the degradation of a variety of contaminants, few of them are based on real wastewater samples. In this paper, the UV/H2O2 AOP was evaluated on the treatment of a hospital laundry wastewater, after the application of a physicochemical pretreatment composed of coagulation-flocculation and anthracite filtration. For the UV/H2O2 process, a photoreactor equipped with a low-pressure UV-C lamp was used and the effects of initial pH and [H2O2]/chemical oxygen demand (COD) ratio on COD removal were investigated through a randomized factorial block design that considered the batches of effluent as blocks. The results indicated that the initial pH had no significant effect on the COD removal, and the process was favored by the increase in [H2O2]/COD ratio. Color and turbidity were satisfactorily reduced after the application of the physicochemical pretreatment, and COD was completely removed by the UV/H2O2 process under suitable conditions. The results of this study show that the UV/H2O2 AOP is a promising candidate for hospital laundry wastewater treatment and should be explored to enable wastewater reuse in the washing process.
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Affiliation(s)
- Jaqueline Pirão Zotesso
- Department of Chemical Engineering, State University of Maringá, Av. Colombo, 5790 - Bloco D90, CEP 87020-900, Maringá, PR, Brazil.
| | - Eneida Sala Cossich
- Department of Chemical Engineering, State University of Maringá, Av. Colombo, 5790 - Bloco D90, CEP 87020-900, Maringá, PR, Brazil
| | - Vanderly Janeiro
- Department of Statistics, State University of Maringá, Av. Colombo, 5790 - Bloco D90, CEP 87020-900, Maringá, PR, Brazil
| | - Célia Regina Granhen Tavares
- Department of Chemical Engineering, State University of Maringá, Av. Colombo, 5790 - Bloco D90, CEP 87020-900, Maringá, PR, Brazil
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11
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Zhang Y, Klamerth N, Messele SA, Chelme-Ayala P, Gamal El-Din M. Kinetics study on the degradation of a model naphthenic acid by ethylenediamine-N,N'-disuccinic acid-modified Fenton process. JOURNAL OF HAZARDOUS MATERIALS 2016; 318:371-378. [PMID: 27442987 DOI: 10.1016/j.jhazmat.2016.06.063] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Revised: 06/22/2016] [Accepted: 06/30/2016] [Indexed: 06/06/2023]
Abstract
Naphthenic acids (NAs) are reported to be the main species responsible for the oil sands process-affected water (OSPW) toxicity. In this study, the degradation of cyclohexanoic acid (CHA) as a model compound for NAs by an ethylenediamine-N,N'-disuccinic acid (EDDS)-modified Fenton process was investigated at pH 8. Optimum dose for Fe-EDDS (EDDS:Fe=2:1) was 0.45mM, and 2.94mM for hydrogen peroxide (H2O2). The time profiles of the main species in the process were studied, including CHA, H2O2, Fe(II), total Fe, and Fe-EDDS (in the main form of Fe(III)EDDS). The second-order rate constant between EDDS and hydroxyl radical (OH) at pH 8 was obtained as 2.48±0.43×10(9)M(-1)s(-1). OH was proved to be the main species responsible for the CHA degradation, while superoxide radical (O2(-)) played a minor role. The consecutive addition of H2O2 and Fe-EDDS led to a higher removal of CHA compared to that achieved by adding the reagents at a time. The half-wave potential of Fe(III/II)EDDS was measured at pH 7-9. The EDDS-modified Fenton process is a promising alternative to degrade NAs.
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Affiliation(s)
- Ying Zhang
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, AB, T6G 1H9, Canada
| | - Nikolaus Klamerth
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, AB, T6G 1H9, Canada
| | - Selamawit Ashagre Messele
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, AB, T6G 1H9, Canada
| | - Pamela Chelme-Ayala
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, AB, T6G 1H9, Canada
| | - Mohamed Gamal El-Din
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, AB, T6G 1H9, Canada.
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12
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Zhang N, Geronimo I, Paneth P, Schindelka J, Schaefer T, Herrmann H, Vogt C, Richnow HH. Analyzing sites of OH radical attack (ring vs. side chain) in oxidation of substituted benzenes via dual stable isotope analysis (δ(13)C and δ(2)H). THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 542:484-494. [PMID: 26520272 DOI: 10.1016/j.scitotenv.2015.10.075] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2015] [Revised: 10/14/2015] [Accepted: 10/14/2015] [Indexed: 06/05/2023]
Abstract
OH radicals generated by the photolysis of H2O2 can degrade aromatic contaminants by either attacking the aromatic ring to form phenolic products or oxidizing the substituent. We characterized these competing pathways by analyzing the carbon and hydrogen isotope fractionation (εC and εH) of various substituted benzenes. For benzene and halobenzenes that only undergo ring addition, low values of εC (-0.7‰ to -1.0‰) were observed compared with theoretical values (-7.2‰ to -8‰), possibly owing to masking effect caused by pre-equilibrium between the substrate and OH radical preceding the rate-limiting step. In contrast, the addition of OH radicals to nitrobenzene ring showed a higher εC (-3.9‰), probably due to the lower reactivity. Xylene isomers, anisole, aniline, N,N-dimethylaniline, and benzonitrile yielded normal εH values (-2.8‰ to -29‰) indicating the occurrence of side-chain reactions, in contrast to the inverse εH (11.7‰ to 30‰) observed for ring addition due to an sp(2) to sp(3) hybridization change at the reacting carbon. Inverse εH values for toluene (14‰) and ethylbenzene (30‰) were observed despite the formation of side-chain oxidation products, suggesting that ring addition has a larger contribution to isotope fractionation. Dual element isotope slopes (∆δ(2)H/∆δ(13)C) therefore allow identification of significant degradation pathways of aromatic compounds by photochemically induced OH radicals. Issues that should be addressed in future studies include quantitative determination of the contribution of each competing pathway to the observed isotope fractionation and characterization of physical processes preceding the reaction that could affect isotope fractionation.
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Affiliation(s)
- Ning Zhang
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research-UFZ, Permoserstraße 15, 04318 Leipzig, Germany
| | - Inacrist Geronimo
- Institute of Applied Radiation Chemistry, Lodz University of Technology, Żeromskiego 116, 90-924 Łódź, Poland
| | - Piotr Paneth
- Institute of Applied Radiation Chemistry, Lodz University of Technology, Żeromskiego 116, 90-924 Łódź, Poland
| | - Janine Schindelka
- Department of Chemistry, Leibniz Institute for Tropospheric Research (TROPOS), Permoserstraße 15, 04318 Leipzig, Germany
| | - Thomas Schaefer
- Department of Chemistry, Leibniz Institute for Tropospheric Research (TROPOS), Permoserstraße 15, 04318 Leipzig, Germany
| | - Hartmut Herrmann
- Department of Chemistry, Leibniz Institute for Tropospheric Research (TROPOS), Permoserstraße 15, 04318 Leipzig, Germany
| | - Carsten Vogt
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research-UFZ, Permoserstraße 15, 04318 Leipzig, Germany
| | - Hans H Richnow
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research-UFZ, Permoserstraße 15, 04318 Leipzig, Germany.
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13
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Mahbub P, Nesterenko PN. Application of photo degradation for remediation of cyclic nitramine and nitroaromatic explosives. RSC Adv 2016. [DOI: 10.1039/c6ra12565d] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Photo degradation is a rapid and safe remediation process and advances in continuous-flow photochemistry can scale-up yields of photo degradation.
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Affiliation(s)
- P. Mahbub
- Australian Centre for Research on Separation Science
- School of Physical Sciences
- University of Tasmania
- Hobart 7001
- Australia
| | - P. N. Nesterenko
- Australian Centre for Research on Separation Science
- School of Physical Sciences
- University of Tasmania
- Hobart 7001
- Australia
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14
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Vidal E, Negro A, Cassano A, Zalazar C. Simplified reaction kinetics, models and experiments for glyphosate degradation in water by the UV/H2O2process. Photochem Photobiol Sci 2015; 14:366-77. [DOI: 10.1039/c4pp00248b] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This work reports the degradation kinetics of glyphosate in water employing the UV/H2O2process. The kinetic model was experimentally validated. Results compare the kinetics of the herbicide alone and a commercial formulation.
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Affiliation(s)
- Eduardo Vidal
- INTEC (UNL-CONICET)
- Santa Fe
- Argentina
- Facultad de Humanidades y Ciencias
- FHUC
| | | | - Alberto Cassano
- INTEC (UNL-CONICET)
- Santa Fe
- Argentina
- Departamento de Medio Ambiente
- FICH
| | - Cristina Zalazar
- INTEC (UNL-CONICET)
- Santa Fe
- Argentina
- Departamento de Medio Ambiente
- FICH
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15
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Sindelar HR, Brown MT, Boyer TH. Evaluating UV/H₂O₂, UV/percarbonate, and UV/perborate for natural organic matter reduction from alternative water sources. CHEMOSPHERE 2014; 105:112-118. [PMID: 24405969 DOI: 10.1016/j.chemosphere.2013.12.040] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Revised: 12/06/2013] [Accepted: 12/11/2013] [Indexed: 06/03/2023]
Abstract
Natural organic matter (NOM) continues to increase in drinking water sources due to many factors, including changes in land use and global climate. Water treatment facilities will need to evaluate the best treatment options to account for these higher NOM levels. The UV/H₂O₂ advanced oxidation process (AOP) is one treatment option that has shown success at reducing high levels of NOM. As a result, this study evaluated the UV/H₂O₂ for the reduction of NOM in a high NOM water matrix, the Florida Everglades. In addition to liquid H₂O₂, sodium percarbonate and sodium perborate were used as oxidants to evaluate their performance as alternatives to liquid H₂O₂. Results showed that all three oxidants were able to reduce aromatic carbon (UV₂₅₄) by 46-66% and dissolved organic carbon (DOC) by 11-19% at UV fluences of 2.6-2.7 J cm(-2) and an H₂O₂ dose of 100 mg L(-1). When the UV fluences were increased to 21.8-26.1 J cm(-2) at an H₂O₂ dose of 100 mg L(-1), UV₂₅₄ reduction increased to 79-97% and DOC to 42-82% for all three oxidants. All three oxidants performed statistically similar for UV₂₅₄ reduction. However, for DOC reduction, H₂O₂ performed statically better than both percarbonate and perborate, and perborate performed statistically better than percarbonate. While the UV/H₂O₂ AOP is effective for NOM reduction in high NOM waters, advances in electrical efficiency are needed to make it economically feasible.
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Affiliation(s)
- Hugo R Sindelar
- Department of Environmental Engineering Sciences, University of Florida, P.O. Box 116450, Gainesville, FL 32611-6450, USA
| | - Mark T Brown
- Department of Environmental Engineering Sciences, University of Florida, P.O. Box 116450, Gainesville, FL 32611-6450, USA
| | - Treavor H Boyer
- Department of Environmental Engineering Sciences, University of Florida, P.O. Box 116450, Gainesville, FL 32611-6450, USA.
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16
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da Silva SS, Chiavone-Filho O, Neto ELDB, Mota ALN, Foletto EL, Nascimento CAO. Photodegradation of non-ionic surfactant with different ethoxy groups in aqueous effluents by the photo-Fenton process. ENVIRONMENTAL TECHNOLOGY 2014; 35:1556-1564. [PMID: 24701956 DOI: 10.1080/09593330.2013.873485] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The photo-Fenton process was applied to degrade non-ionic surfactants with different numbers of ethoxy groups, seven (E7), ten (E10) and twenty-three (E23). The effects of H2O2 concentration, Fe(II) concentration and number of ethoxy groups on the mineralization of surfactants were investigated. The response surface methodology (RSM) was applied to determine optimal concentrations of Fenton's reagents for each surfactant. The efficiency of the photo-Fenton process reached 95% for all surfactants studied at 45 min in optimal conditions determined in this work. The analysis of results showed that the efficiency depends upon the number of ethoxy groups in the surfactant. The increase in ethoxy groups favoured the mineralization of surfactants. The analysis of variance (ANOVA) was applied, and according to the F-test the models for the mineralization of surfactants were considered significant and predictable. The photo-Fenton process has proven to be feasible for the degradation of ethoxylated surfactants in aqueous solution.
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17
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Zuorro A, Fidaleo M, Fidaleo M, Lavecchia R. Degradation and antibiotic activity reduction of chloramphenicol in aqueous solution by UV/H2O2 process. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2014; 133:302-308. [PMID: 24412593 DOI: 10.1016/j.jenvman.2013.12.012] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Revised: 11/26/2013] [Accepted: 12/07/2013] [Indexed: 06/03/2023]
Abstract
The efficacy of the UV/H2O2 process to degrade the antibiotic chloramphenicol (CHL) was investigated at 20 °C using a low-pressure mercury lamp as UV source. A preliminary analysis of CHL degradation showed that the process followed apparent first-order kinetics and that an optimum H2O2 concentration existed for the degradation rate. The first-order rate constant was used as the response variable and its dependence on initial CHL and H2O2 concentrations, UV light intensity and reaction time was investigated by a central composite design based on the response surface methodology. Analysis of response surface plots revealed a large positive effect of radiation intensity, a negative effect of CHL concentration and that there was a region of H2O2 concentration leading to maximum CHL degradation. CHL solutions submitted to the UV/H2O2 process were characterized by TOC and their activity against Escherichia coli and Staphylococcus aureus was assessed. No residual antibiotic activity was detected, even at CHL concentrations higher than those used in the designed experiments. Overall, the obtained results strongly support the possibility of reducing the risks associated with the release of CHL into the environment, including the spread of antibiotic resistance, by the UV/H2O2 process.
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Affiliation(s)
- Antonio Zuorro
- Department of Chemical Engineering, Materials & Environment, Sapienza University, Via Eudossiana 18, 00184 Roma, Italy
| | - Marco Fidaleo
- Laboratory of Molecular Neuroembryology, IRCCS Fondazione Santa Lucia, Roma, Italy
| | - Marcello Fidaleo
- Department for Innovation in Biological, Agro-Food and Forest Systems, University of Tuscia, Viterbo, Italy
| | - Roberto Lavecchia
- Department of Chemical Engineering, Materials & Environment, Sapienza University, Via Eudossiana 18, 00184 Roma, Italy.
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18
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Soltani T, Entezari MH. Photolysis and photocatalysis of methylene blue by ferrite bismuth nanoparticles under sunlight irradiation. ACTA ACUST UNITED AC 2013. [DOI: 10.1016/j.molcata.2013.05.004] [Citation(s) in RCA: 183] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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19
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Spectroscopic characterization and photoinduced processes of 4-oxoquinoline derivatives. J Photochem Photobiol A Chem 2011. [DOI: 10.1016/j.jphotochem.2011.09.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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20
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Chen HW, Chen CY, Wang GS. Performance evaluation of the UV/H2O2 process on selected nitrogenous organic compounds: reductions of organic contents vs. corresponding C-, N-DBPs formations. CHEMOSPHERE 2011; 85:591-597. [PMID: 21782208 DOI: 10.1016/j.chemosphere.2011.06.090] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Revised: 06/20/2011] [Accepted: 06/21/2011] [Indexed: 05/31/2023]
Abstract
The presence of various organic contaminants in water sources is of concern due to their direct threats to human health and potential to react with disinfectants to form carcinogenic byproducts including trihalomethanes, haloacetic acids and nitrosamines in finished water. This study applied both medium-pressure and low-pressure ultraviolet light coupled with hydrogen peroxide (UV/H2O2) to evaluate its efficacy for degradation of selected nitrogenous organic compounds and corresponding disinfection byproduct (DBP) formation. Six organic compounds were chosen as target precursors based on their nitrogen contents and molecular structures. The results showed that higher oxidation capacity resulted in better reduction of organic matters and DBP formation potentials (DBPFPs). However, insufficient contact time and oxidant doses could lead to a rise of DBPFPs in the early stages of UV/H2O2 reactions. A greater percentage removal was achieved for organic carbon than organic nitrogen after UV/H2O2 treatment, especially for compounds with complicated structure such as diltiazem. During the UV/H2O2 treatment, the intermediate products include tertiary amine, dimethyl amine (DMA) or DMA-like structures, which are N-nitrosodimethylamine (NDMA) precursors after chlorination or chloramination. Furthermore, it was observed that using dissolved organic nitrogen and DMA to predict NDMAFP could lead to biased conclusions because of the complex nature of nitrogenous matters in aqueous environments.
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Affiliation(s)
- Huei-Wen Chen
- Institute of Environmental Health, National Taiwan University, Taipei, Taiwan
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21
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Kholod YA, Gryn'ova G, Gorb L, Hill FC, Leszczynski J. Evaluation of the dependence of aqueous solubility of nitro compounds on temperature and salinity: a COSMO-RS simulation. CHEMOSPHERE 2011; 83:287-294. [PMID: 21215986 DOI: 10.1016/j.chemosphere.2010.12.065] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2010] [Revised: 12/10/2010] [Accepted: 12/13/2010] [Indexed: 05/30/2023]
Abstract
The solubility in pure and saline water at various temperatures was calculated for selected nitro compounds (nitrobenzene, 1,3,5-trinitrobenzene, 2-nitrotoluene, 3-nitrotoluene, 4-nitrotoluene, 2,4-dinitrotoluene, 2,6-dinitrotoluene, 2,3-dinitrotoluene, 3,4-dinitrotoluene, 2,4,6-trinitrotoluene) using the Conductor-like Screening model for Real Solvents (COSMO-RS). The results obtained were compared with experimental values. The COSMO-RS predictions have shown high accuracy in reproducing the trends of aqueous solubilities for both temperature and salinity. The proposed methodology was then applied to predict the aqueous solubilities of 19 nitro compounds in the temperature range of 5-50°C in saline solutions. The salting-out parameters of the Setschenow equation were also calculated. The predicted salting-out parameters were overestimated when compared to the measured values, but these parameters can still be used for qualitative estimation of the trends.
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Affiliation(s)
- Yana A Kholod
- Interdisciplinary Center for Nanotoxicity, Department of Chemistry, Jackson State University, Jackson, MS 39217, USA.
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22
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Abramović BF, Banić ND, Sojić DV. Degradation of thiacloprid in aqueous solution by UV and UV/H2O2 treatments. CHEMOSPHERE 2010; 81:114-119. [PMID: 20692009 DOI: 10.1016/j.chemosphere.2010.07.016] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2010] [Revised: 07/09/2010] [Accepted: 07/12/2010] [Indexed: 05/29/2023]
Abstract
Although some studies concerning flash photolysis and photocatalytic ozonation of thiacloprid have already been published, no complete investigation and explanation of the effects of thiacloprid photodegradation under the conditions of UV and UV/H(2)O(2) (high-pressure mercury lamp and H(2)O(2)) have been reported yet. The photochemical degradation of thiacloprid (0.32 mM) was studied under a variety of solution conditions, by varying the initial concentrations of H(2)O(2) from 0 to 162 mM and the pH from 2.8 to 9. In the UV/H(2)O(2) system, thiacloprid reacted rapidly, the maximum first-order rate constant (2.7 x 10(-2)min(-1), r=0.9996) being observed at the H(2)O(2)/thiacloprid molar ratio of 220 and pH 2.8. Under these conditions, 97% of the thiacloprid was removed in about 120 min. The thiacloprid degradation is accompanied by the formation of a number of ionic byproducts (Cl(-), acetate, formate, SO(4)(2-), and NH(4)(+)) and organic intermediates, so that after 35 h of irradiation, 17% of organic carbon remained non-degraded. The application of UV radiation, or H(2)O(2) alone, yielded no significant thiacloprid degradation. The study of the rate of removal of thiacloprid from natural water showed that it is dominantly influenced by the presence of HCO(3)(-).
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Affiliation(s)
- Biljana F Abramović
- Faculty of Sciences, Department of Chemistry, Biochemistry and Environmental Protection, Trg D. Obradovića 3, 21000 Novi Sad, Serbia.
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23
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Wu C, Linden KG. Phototransformation of selected organophosphorus pesticides: roles of hydroxyl and carbonate radicals. WATER RESEARCH 2010; 44:3585-94. [PMID: 20537677 PMCID: PMC3758901 DOI: 10.1016/j.watres.2010.04.011] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2010] [Revised: 03/17/2010] [Accepted: 04/10/2010] [Indexed: 05/17/2023]
Abstract
The phototransformation of two organophosphorus pesticides, parathion and chlorpyrifos, by hydroxyl radicals and carbonate radicals in aqueous solution were studied. Addition of hydrogen peroxide increased the UV degradation rates of both pesticides and data were simulated through kinetic modeling. The second-order rate constants of parathion and chlorpyrifos with hydroxyl radical were determined to be 9.7 +/- 0.5 x 10(9) and 4.9 +/- 0.1 x 10(9) M(-1) s(-1), respectively. The presence of bi/carbonate ions reduced the pesticide degradation rates via scavenging of hydroxyl radical but the formation of carbonate radical also contributed to the degradation of the pesticides with second-order reaction rate constants of 2.8 +/- 0.2 x 10(6) and 8.8 +/- 0.4 x 10(6) M(-1) s(-1) for parathion and chlorpyrifos, respectively. The dual roles of bicarbonate ion in UV/H2O2 treatment systems, i.e., scavenging of hydroxyl radicals and formation of carbonate radicals, were examined and discussed using a simulative kinetic model. The transformation of pesticides by carbonate radicals at environmentally relevant bi/carbonate concentrations was shown to be a significant contributor to the environmental fate of the pesticides and it reshaped the general phototransformation kinetics of both pesticides in UV/H2O2 systems.
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Affiliation(s)
- Changlong Wu
- Department of Civil and Environmental Engineering, Duke University, Box 90287, Durham, North Carolina 27708-0287
| | - Karl G. Linden
- Department of Civil, Environmental, and Architectural Engineering, University of Colorado at Boulder; Boulder, CO 80309, Phone: (303) 492-4798, Fax: (303) 492-7317;
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24
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Carlos L, Nichela D, Triszcz JM, Felice JI, García Einschlag FS. Nitration of nitrobenzene in Fenton's processes. CHEMOSPHERE 2010; 80:340-345. [PMID: 20417542 DOI: 10.1016/j.chemosphere.2010.03.034] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2009] [Revised: 03/22/2010] [Accepted: 03/23/2010] [Indexed: 05/29/2023]
Abstract
Previous studies of nitrobenzene (NB) degradation by Fenton and photo-Fenton technologies have demonstrated the formation and accumulation of 1,3-dinitrobenzene (1,3-DNB) as a highly toxic reaction intermediate. In the present study, we analyze the conditions that favor 1,3-DNB formation during NB degradation by Fe(2+)/H(2)O(2), Fe(3+)/H(2)O(2), UV/Fe(3+)/H(2)O(2) or UV/H(2)O(2) processes. Nitration yields in Fenton, Fenton-like and photo-Fenton techniques were much higher than those observed in UV/H(2)O(2) systems. Besides, several tests showed that 1,3-DNB formation increases with the initial iron concentration and decreases as the initial H(2)O(2) concentration increases. In order to asses the key species involved in NB nitration mechanism, additional experiments were performed in the presence of NO(2)(-)or NO(3)(-). In dark systems, 1,3-DNB yield significantly increased with increasing [NO(2)(-)]_(0), while it was not affected by the presence of NO(3)(-). In contrast, 1,3-DNB yields were higher and more strongly affected by the additive concentration in UV/NO(3)(-) systems than in UV/HNO(2)/NO(2)(-) systems. Dark experiments performed at pH 1.5 in excess of HNO(2) along with UV/NO(3)(-) tests conducted in the presence of 2-propanol show that hydroxyl radicals play an important role in NB nitration since NB molecule does not react with the nitrating agents ONOOH, .NO or .NO(2). The results indicate that, in the experimental domain tested, the prevailing NB nitration pathway involves the reaction between the .OH-NB adduct and .NO(2) radicals.
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Affiliation(s)
- Luciano Carlos
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas, CCT-La Plata-CONICET, Departamento de Química, Facultad de Ciencias Exactas, UNLP, La Plata, Argentina
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25
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Yuan F, Hu C, Hu X, Qu J, Yang M. Degradation of selected pharmaceuticals in aqueous solution with UV and UV/H(2)O(2). WATER RESEARCH 2009; 43:1766-74. [PMID: 19232423 DOI: 10.1016/j.watres.2009.01.008] [Citation(s) in RCA: 167] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2008] [Revised: 01/14/2009] [Accepted: 01/14/2009] [Indexed: 05/17/2023]
Abstract
The degradation of four pharmaceutical compounds (PhACs), ibuprofen (IBU), diphenhydramine (DP), phenazone (PZ), and phenytoin (PHT) was investigated via ultraviolet (UV) photolysis and UV/H(2)O(2) process with a low-pressure (LP) UV lamp. For each PhAC tested, direct photolysis quantum yields at 254 nm were found to be ranging from 6.32 x 10(-2) to 2.79 x 10(-1)molE(-1) at pH 7. The second-order rate constants of the reaction between the PhACs and OH were determined to be from 4.86 x 10(9) to 6.67 x 10(9)M(-1)s(-1) by using a competition kinetic model which utilized para-chlorobenzoic acid (pCBA) as a reference compound. The overall effect of OH radical scavenging from humic acid (HA) and anions HCO(3)(-), NO(3)(-) was measured utilizing R(OH,UV) method through examining the aqueous photodegradation of pCBA as a probe compound. Moreover, these fundamental direct and indirect photolysis parameters were applied in the model prediction for oxidation rate constants of the PhACs in UV/H(2)O(2) process. It was found that the predicted oxidation rate constants approximated the observed ones. The results indicated that the new R(OH,UV) probe compound method was applicable for measuring background OH radical scavenging effects in water treatment process of UV/H(2)O(2). Furthermore, by GC-MS analysis, most of the intermediates created during the photodegradation of the selected PhACs in UV/H(2)O(2) process were identified. For the photodegradation of PZ, a competition mechanism existed between the direct UV photolysis and the oxidation of OH. An appropriate dosage of H(2)O(2) could hinder the occurrence of the direct photolysis.
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Affiliation(s)
- Fang Yuan
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
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26
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Olmez-Hanci T, Imren C, Arslan-Alaton I, Kabdaşlı I, Tünay O. H2O2/UV-C oxidation of potential endocrine disrupting compounds: a case study with dimethyl phthalate. Photochem Photobiol Sci 2009; 8:620-7. [DOI: 10.1039/b817420b] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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27
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García Einschlag FS, Felice JI, Triszcz JM. Kinetics of nitrobenzene and 4-nitrophenol degradation by UV irradiation in the presence of nitrate and nitrite ions. Photochem Photobiol Sci 2009; 8:953-60. [DOI: 10.1039/b901835b] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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28
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Wu C, Linden KG. Degradation and byproduct formation of parathion in aqueous solutions by UV and UV/H(2)O(2) treatment. WATER RESEARCH 2008; 42:4780-90. [PMID: 18834610 PMCID: PMC3758902 DOI: 10.1016/j.watres.2008.08.023] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2008] [Revised: 08/16/2008] [Accepted: 08/20/2008] [Indexed: 05/05/2023]
Abstract
The photodegradation of parathion in aqueous solutions by UV and UV/H(2)O(2) processes was evaluated. Direct photolysis of parathion both by LP (low pressure) and MP (medium pressure) lamps at pH 7 was very slow with quantum yields of 6.67+/-0.33x10(-4) and 6.00+/-1.06x10(-4)molE(-1), respectively. Hydrogen peroxide enhanced the photodegradation of parathion through the reaction between UV generated hydroxyl radical and parathion with a second-order reaction rate constant of 9.70+/-0.45x10(9)M(-1)s(-1). An optimum molar ratio between hydrogen peroxide and parathion was determined to be between 300 and 400. Photodegradation of parathion yielded several organic byproducts, of which the paraoxon, 4-nitrophenol, O,O,O-triethyl thiophosphate and O,O-diethyl-methyl thiophosphate were quantified and their occurrence during UV/H(2)O(2) processes were discussed. NO(2)(-), PO(4)(3-), NO(3)(-) and SO(4)(2-) were the major anionic byproducts of parathion photodegradation and their recover ratios were also discussed. A photodegradation scheme suggesting three simultaneous pathways was proposed in the study.
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Affiliation(s)
- Changlong Wu
- Department of Civil and Environmental Engineering, Duke University, Durham, North Carolina 27708-0287
| | - Karl G. Linden
- Department of Civil, Environmental, and Architectural Engineering, University of Colorado at Boulder; Boulder, CO 80309
- Corresponding Author, Phone: (303) 492-4798, Fax: (303) 492-7317;
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29
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Alibegic D, Tsuneda S, Hirata A. Oxidation of Tetrachloroethylene in a Bubble Column Photochemical Reactor Applying the UV/H2O2 Technique. CAN J CHEM ENG 2008. [DOI: 10.1002/cjce.5450810353] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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30
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31
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Zalazar CS, Labas MD, Brandi RJ, Cassano AE. Dichloroacetic acid degradation employing hydrogen peroxide and UV radiation. CHEMOSPHERE 2007; 66:808-15. [PMID: 16904730 DOI: 10.1016/j.chemosphere.2006.06.044] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2006] [Revised: 06/14/2006] [Accepted: 06/16/2006] [Indexed: 05/11/2023]
Abstract
The degradation reaction of dichloroacetic acid employing H(2)O(2) and UVC radiation (253.7nm) has been studied in a well mixed reactor operating inside a recycling system. It has been shown that in an aqueous solution no stable reaction intermediates are formed and, at every time during the reaction, two mols of hydrochloric acid are formed for every mol of dichloroacetic acid that is decomposed and, in the same way, there is a paired agreement between the calculated TOC concentration corresponding to the unaltered dichloroacetic acid and the experimental values measured in the solution. On this basis and classical references from the scientific literature for the H(2)O(2) photolysis, a complete reaction scheme, apt for reaction kinetics mathematical modeling and ulterior scale-up is proposed.
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Affiliation(s)
- Cristina S Zalazar
- INTEC (Universidad Nacional del Litoral and CONICET), Güemes 3450. (3000) Santa Fe, Argentina
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32
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Priya M, Madras G. Photocatalytic degradation of nitrobenzenes with combustion synthesized nano-TiO2. J Photochem Photobiol A Chem 2006. [DOI: 10.1016/j.jphotochem.2005.06.012] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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33
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Chiş V. Molecular and vibrational structure of 2,4-dinitrophenol: FT-IR, FT-Raman and quantum chemical calculations. Chem Phys 2004. [DOI: 10.1016/j.chemphys.2004.01.003] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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34
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Brillas E, Baños MA, Camps S, Arias C, Cabot PL, Garrido JA, Rodríguez RM. Catalytic effect of Fe2+, Cu2+and UVA light on the electrochemical degradation of nitrobenzene using an oxygen-diffusion cathode. NEW J CHEM 2004. [DOI: 10.1039/b312445b] [Citation(s) in RCA: 126] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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35
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García Einschlag FS, Carlos L, Capparelli AL. Competition kinetics using the UV/H2O2 process: a structure reactivity correlation for the rate constants of hydroxyl radicals toward nitroaromatic compounds. CHEMOSPHERE 2003; 53:1-7. [PMID: 12892661 DOI: 10.1016/s0045-6535(03)00388-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The rate constants for hydroxyl radical reaction toward a set of nitroaromatic substrates kS, have been measured at 25 degrees C using competition experiments in the UV/H2O2 process. For a given pair of substrates S1 and S2, the relative reactivity beta (defined as kS1/kS2) was calculated from the slope of the corresponding double logarithmic plot, i.e., of ln[S1] vs. ln[S2]. This method is more accurate and remained linear for larger conversions in comparison with the plots of ln[S1] and ln[S2] against time. The rate constants measured ranged from 0.33 to 8.6 x 10(9) M(-1)s(-1). A quantitative structure-reactivity relationship was found using the Hammett equation. Assuming sigma values to be additive, a value of -0.60 was obtained for the reaction constant rho. This value agrees with the high reactivity and the electrophilic nature of HO* radical.
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Affiliation(s)
- Fernando S García Einschlag
- Instituto de Investigaciones Fisicoquímica Teóricas y Aplicadas, Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Casilla de Correo 16, Sucursal 4, 1900 La Plata, Argentina.
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