151
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Khan S, He X, Khan HM, Boccelli D, Dionysiou DD. Efficient degradation of lindane in aqueous solution by iron (II) and/or UV activated peroxymonosulfate. J Photochem Photobiol A Chem 2016. [DOI: 10.1016/j.jphotochem.2015.10.004] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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152
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Kuppusamy S, Palanisami T, Megharaj M, Venkateswarlu K, Naidu R. Ex-Situ Remediation Technologies for Environmental Pollutants: A Critical Perspective. REVIEWS OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2016; 236:117-192. [PMID: 26423074 DOI: 10.1007/978-3-319-20013-2_2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Pollution and the global health impacts from toxic environmental pollutants are presently of great concern. At present, more than 100 million people are at risk from exposure to a plethora of toxic organic and inorganic pollutants. This review is an exploration of the ex-situ technologies for cleaning-up the contaminated soil, groundwater and air emissions, highlighting their principles, advantages, deficiencies and the knowledge gaps. Challenges and strategies for removing different types of contaminants, mainly heavy metals and priority organic pollutants, are also described.
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Affiliation(s)
- Saranya Kuppusamy
- CERAR-Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes, SA, 5095, Australia
- CRC CARE-Cooperative Research Centre for Contamination Assessment and Remediation of Environment, 486, Salisbury South, SA, 5106, Australia
| | - Thavamani Palanisami
- CRC CARE-Cooperative Research Centre for Contamination Assessment and Remediation of Environment, 486, Salisbury South, SA, 5106, Australia
- GIER- Global Institute for Environmental Research, Faculty of Science and Information Technology, The University of Newcastle, Callaghan, NSW, 2308, Australia
| | - Mallavarapu Megharaj
- CRC CARE-Cooperative Research Centre for Contamination Assessment and Remediation of Environment, 486, Salisbury South, SA, 5106, Australia.
- GIER- Global Institute for Environmental Research, Faculty of Science and Information Technology, The University of Newcastle, Callaghan, NSW, 2308, Australia.
| | - Kadiyala Venkateswarlu
- Formerly Department of Microbiology, Sri Krishnadevaraya University, Anantapur, 515055, India
| | - Ravi Naidu
- CRC CARE-Cooperative Research Centre for Contamination Assessment and Remediation of Environment, 486, Salisbury South, SA, 5106, Australia
- GIER- Global Institute for Environmental Research, Faculty of Science and Information Technology, The University of Newcastle, Callaghan, NSW, 2308, Australia
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153
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Kerzig C, Goez M. Generating hydrated electrons through photoredox catalysis with 9-anthrolate. Phys Chem Chem Phys 2015; 17:13829-36. [PMID: 25929856 DOI: 10.1039/c5cp01711d] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Hydrated electrons are among the strongest reductants known. Adding the ascorbate dianion as a sacrificial donor turns the photoionization of 9-anthrolate in water into a catalytic cycle for their in situ production with near-UV light (355 nm). The photoionization step is exclusively biphotonic and occurs via the first excited singlet state of the catalyst. Neither triplet formation nor any photochemical side reactions interfere. The ionization by-product, the anthroxy radical, is inert towards the ascorbate monoanion but is rapidly reduced by the dianion, thereby recovering the starting catalyst. A sufficient amount of the sacrificial donor makes that reduction quantitative and leads to a sustainable generation of hydrated electrons, as is evidenced by electron yields greatly surpassing the catalyst concentration. Control experiments established that the superincrease is indeed due to the catalyst regeneration and not to an ionization of other species involved in the reaction.
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Affiliation(s)
- Christoph Kerzig
- Martin-Luther-Universität Halle-Wittenberg, Institut für Chemie, Kurt-Mothes-Str. 2, D-06120 Halle (Saale), Germany.
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154
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Xie P, Ma J, Liu W, Zou J, Yue S, Li X, Wiesner MR, Fang J. Removal of 2-MIB and geosmin using UV/persulfate: contributions of hydroxyl and sulfate radicals. WATER RESEARCH 2015; 69:223-233. [PMID: 25486622 DOI: 10.1016/j.watres.2014.11.029] [Citation(s) in RCA: 262] [Impact Index Per Article: 29.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Revised: 09/27/2014] [Accepted: 11/17/2014] [Indexed: 06/04/2023]
Abstract
2-methylisoborneol (2-MIB) and geosmin are two odor-causing compounds that are difficult to remove and the cause of many consumer complaints. In this study, we assessed the degradation of 2-MIB and geosmin using a UV/persulfate process for the first time. The results showed that both 2-MIB and geosmin could be degraded effectively using this process. The process was modeled based on steady-state assumption with respect to the odor-causing compounds and either hydroxyl or sulfate radicals. The second order rate constants for 2-MIB and geosmin reacting with the sulfate radical (SO4(-)) were estimated to be (4.2 ± 0.6) × 10(8) M(-1)s(-1) and (7.6 ± 0.6) × 10(8) M(-1)s(-1) respectively at a pH of 7.0. The contributions of the hydroxyl radical (OH) to 2-MIB and geosmin degradation were 3.5 times and 2.0 times higher, respectively, than the contribution from SO4(-) in Milli-Q water with 2 mM phosphate buffer at pH 7.0. The pseudo-first-order rate constants (ko(s)) of both 2-MIB and geosmin increased with increasing dosages of persulfate. Although pH did not affect the degradation of 2-MIB and geosmin directly, different scavenging effects of hydrogen phosphate and dihydrogen phosphate resulted in higher values of ko(s) for both 2-MIB and geosmin in acidic condition. Bicarbonate and natural organic matter (NOM) inhibited the degradation of both 2-MIB and geosmin dramatically through consuming OH and SO4(-) and were likely to be the main radical scavengers in natural waters when using UV/persulfate process to control 2-MIB and geosmin.
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Affiliation(s)
- Pengchao Xie
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Jun Ma
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
| | - Wei Liu
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Jing Zou
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Siyang Yue
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Xuchun Li
- School of the Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310012, China
| | - Mark R Wiesner
- Civil and Environmental Engineering, Duke University, Durham 27708-0287, USA
| | - Jingyun Fang
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China
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155
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Li X, Fang J, Liu G, Zhang S, Pan B, Ma J. Kinetics and efficiency of the hydrated electron-induced dehalogenation by the sulfite/UV process. WATER RESEARCH 2014; 62:220-228. [PMID: 24956604 DOI: 10.1016/j.watres.2014.05.051] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2014] [Revised: 05/21/2014] [Accepted: 05/26/2014] [Indexed: 06/03/2023]
Abstract
Hydrated electron (e(aq)(-)), which is listed among the most reactive reducing species, has great potential for removal and detoxification of recalcitrant contaminants. Here we provided quantitative insight into the availability and conversion of e(aq)(-) in a newly developed sulfite/UV process. Using monochloroacetic acid as a simple e(aq)(-)-probe, the e(aq)(-)-induced dehalogenation kinetics in synthetic and surface water was well predicted by the developed models. The models interpreted the complex roles of pH and S(IV), and also revealed the positive effects of UV intensity and temperature quantitatively. Impacts of humic acid, ferrous ion, carbonate/bicarbonate, and surface water matrix were also examined. Despite the retardation of dehalogenation by electron scavengers, the process was effective even in surface water. Efficiency of the process was discussed, and the optimization approaches were proposed. This study is believed to better understand the e(aq)(-)-induced dehalogenation by the sulfite/UV process in a quantitative manner, which is very important for its potential application in water treatment.
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Affiliation(s)
- Xuchun Li
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Jingyun Fang
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China
| | - Guifang Liu
- School of Civil Engineering, Harbin Engineering University, Harbin 150001, China
| | - Shujuan Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Bingcai Pan
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China.
| | - Jun Ma
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
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156
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Goez M, Kerzig C, Naumann R. An “All-Green” Catalytic Cycle of Aqueous Photoionization. Angew Chem Int Ed Engl 2014; 53:9914-6. [DOI: 10.1002/anie.201405693] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Indexed: 01/08/2023]
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157
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Goez M, Kerzig C, Naumann R. An “All-Green” Catalytic Cycle of Aqueous Photoionization. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201405693] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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158
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Qu Y, Zhang CJ, Chen P, Zhou Q, Zhang WX. Effect of initial solution pH on photo-induced reductive decomposition of perfluorooctanoic acid. CHEMOSPHERE 2014; 107:218-223. [PMID: 24439837 DOI: 10.1016/j.chemosphere.2013.12.046] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Revised: 12/13/2013] [Accepted: 12/18/2013] [Indexed: 06/03/2023]
Abstract
The effects of initial solution pH on the decomposition of perfluorooctanoic acid (PFOA) with hydrated electrons as reductant were investigated. The reductive decomposition of PFOA depends strongly on the solution pH. In the pH range of 5.0-10.0, the decomposition and defluorination rates of PFOA increased with the increase of the initial solution pH. The rate constant was 0.0295 min(-1) at pH 10.0, which was more than 49.0 times higher than that at pH 5.0. Higher pH also inhibits the generation of toxic intermediates during the PFOA decomposition. For example, the short-chain PFCAs reached a lower maximum concentration in shorter reaction time as pH increasing. The peak areas of accumulated fluorinated and iodinated hydrocarbons detected by GC/MS under acidic conditions were nearly 10-100 times more than those under alkaline conditions. In short, alkaline conditions were more favorable for photo-induced reduction of PFOA as high pH promoted the decomposition of PFOA and inhibited the accumulation of intermediate products. The concentration of hydrated electron, detected by laser flash photolysis, increased with the increase of the initial pH. This was the main reason why the decomposition of PFOA in the UV-KI system depended strongly on the initial pH.
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Affiliation(s)
- Yan Qu
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China
| | - Chao-Jie Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China.
| | - Pei Chen
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China
| | - Qi Zhou
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China
| | - Wei-Xian Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China
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159
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Kerzig C, Goez M. Highly efficient green-light ionization of an aryl radical anion: key step in a catalytic cycle of electron formation. Phys Chem Chem Phys 2014; 16:25342-9. [DOI: 10.1039/c4cp04156a] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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160
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Song Z, Tang H, Wang N, Zhu L. Reductive defluorination of perfluorooctanoic acid by hydrated electrons in a sulfite-mediated UV photochemical system. JOURNAL OF HAZARDOUS MATERIALS 2013; 262:332-338. [PMID: 24056245 DOI: 10.1016/j.jhazmat.2013.08.059] [Citation(s) in RCA: 144] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Revised: 08/22/2013] [Accepted: 08/23/2013] [Indexed: 05/28/2023]
Abstract
A method for reductive degradation of perfluorooctanoic acid (PFOA) was established by using a sulfite/UV process. This process led to a PFOA removal of 100% at about 1h and a defluorination ratio of 88.5% at reaction time of 24h under N2 atmosphere, whereas the use of either UV irradiation or SO3(2-) alone induced little defluorination of PFOA under the same conditions. It was confirmed that the reductive defluorination of PFOA was achieved by hydrated electrons being generated from the photo-conversion of SO3(2-) as a mediator. Theoretical reaction kinetic analysis demonstrated that the generation of hydrated electrons was promoted by increasing either SO3(2-) concentration or solution pH, leading to the acceleration of the PFOA defluorination. Accompanying the reduction of PFOA, a small amount of short-chain perfluorocarboxylic acids, less fluorinated carboxylic acids and perfluorinated alkyl sulfonates were generated, all of which were able to be further degraded with further releasing of fluoride ions. Based on the generation, accumulation and distribution of intermediates, hydrated electrons induced defluorination pathway of PFOA was proposed in a sulfite-mediated UV photochemical system.
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Affiliation(s)
- Zhou Song
- Key Laboratory of Catalysis and Materials Science of the State Ethnic Affairs Commission and Ministry of Education, College of Chemistry and Materials Science, South-Central University for Nationalities, Wuhan 430074, PR China; College of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, PR China
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161
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Liu X, Yoon S, Batchelor B, Abdel-Wahab A. Degradation of vinyl chloride (VC) by the sulfite/UV advanced reduction process (ARP): effects of process variables and a kinetic model. THE SCIENCE OF THE TOTAL ENVIRONMENT 2013; 454-455:578-583. [PMID: 23570912 DOI: 10.1016/j.scitotenv.2013.03.060] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Revised: 03/16/2013] [Accepted: 03/16/2013] [Indexed: 06/02/2023]
Abstract
Vinyl chloride (VC) poses a threat to humans and environment due to its toxicity and carcinogenicity. In this study, an advanced reduction process (ARP) that combines sulfite with UV light was developed to destroy VC. The degradation of VC followed pseudo-first-order decay kinetics and the effects of several experimental factors on the degradation rate constant were investigated. The largest rate constant was observed at pH9, but complete dechlorination was obtained at pH11. Higher sulfite dose and light intensity were found to increase the rate constant linearly. The rate constant had a little drop when the initial VC concentration was below 1.5mg/L and then was approximately constant between 1.5mg/L and 3.1mg/L. A degradation mechanism was proposed to describe reactions between VC and the reactive species that were produced by the photolysis of sulfite. A kinetic model that described major reactions in the system was developed and was able to explain the dependence of the rate constant on the experimental factors examined. This study may provide a new treatment technology for the removal of a variety of halogenated contaminants.
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Affiliation(s)
- Xu Liu
- Zachry Department of Civil Engineering, Texas A&M University, College Station, TX 77843-3136, USA.
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162
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Qian Y, Wang W, Boyd JM, Wu M, Hrudey SE, Li XF. UV-induced transformation of four halobenzoquinones in drinking water. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:4426-4433. [PMID: 23560392 DOI: 10.1021/es305044k] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Halobenzoquinones (HBQs) are a group of emerging disinfection byproducts (DBPs) found in treated drinking water. Because the use of UV treatment for disinfection is becoming more widespread, it is important to understand how the HBQs may be removed or changed due to UV irradiation. Water samples containing four HBQs, 2,6-dichloro-1,4-benzoquinone (DCBQ), 2,3,6-trichloro-1,4-benzoquinone (TCBQ), 2,6-dichloro-3-methyl-1,4-benzoquinone (DCMBQ), and 2,6-dichloro-1,4-benzoquinone (DBBQ), were treated using a modified bench scale collimated beam device, mimicking UV treatment. Water samples before and after UV irradiation were analyzed for the parent compounds and products using a high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) method. As much as 90% of HBQs (0.25 nmol L(-1)) in both pure water and tap water were transformed to other products after UV254 irradiation at 1000 mJ cm(-2). The major products of the four HBQs were identified as 3-hydroxyl-2,6-dichloro-1,4-benzoquinone (OH-DCBQ) from DCBQ, 5-hydroxyl-2,6-dichloro-3-methyl-1,4-benzoquinone (OH-DCMBQ) from DCMBQ, 5-hydroxyl-2,3,6-trichloro-1,4-benzoquinone (OH-TCBQ) from TCBQ, and 3-hydroxyl-2,6-dibromo-1,4-benzoquinone (OH-DBBQ) from DBBQ. These four OH-HBQs were further modified to monohalogenated benzoquinones when the UV dose was higher than 200 mJ cm(-2). These results suggested possible pathways of UV-induced transformation of HBQs to other compounds. Under the UV dose commonly used in water treatment plants, it is likely that HBQs are partially converted to other halo-DBPs. The occurrence and toxicity of these mixed DBPs warrant further investigation to understand whether they pose a health risk.
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Affiliation(s)
- Yichao Qian
- Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Alberta, Canada, T6G 2G3
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