title: Impact of persulfate and ultraviolet light activated persulfate pre-oxidation on the formation of trihalomethanes, haloacetonitriles and halonitromethanes from the chlor(am)ination of three antibiotic chloramphenicols.
abstract: Persulfate oxidation processes, with and without activation using ultraviolet light (respectively UV/PS and PS) have the potential to degrade anthropogenic chemicals in water. However, little is known about the impact of PS or UV/PS pre-oxidation on downstream formation of disinfection by-products (DBPs). In this study the three antibiotic chloramphenicols (chloramphenicol and two of its analogues [thiamphenicol and florfenicol], referred to collectively as CAPs), which frequently occur in wastewater-impacted source waters used by drinking water treatment plants, were selected as model antibiotic compounds. The formation of carbonaceous and nitrogenous disinfection by-products, including halomethanes, haloacetonitriles and halonitromethanes, during chlorination and chloramination preceded by PS and UV/PS was investigated. No significant concentrations of haloacetonitriles and halonitromethanes were detected during chlorination. During chloramination chloramphenicol formed a considerable amount of dichloronitromethane (e.g., 3.44 ± 0.33% mol/mol at NH2Cl dose = 1 mM) and trichloronitromethane (e.g., 0.79 ± 0.07% mol/mol at NH2Cl dose = 1 mM), compared with THM and HAN formation. PS pre-oxidation achieved a statistically significant reduction in trichloromethane formation from chlorination, and in HAN and HNM formation from chloramination. Although UV/PS slightly increased dichloroacetonitrile formation during chloramination, it significantly decreased dichloronitromethane and trichloronitromethane formation during chloramination. Overall, the use of PS and UV/PS has the potential to have contrasting impacts on DBP formation in heavily wastewater-impacted waters, depending on the disinfection method. Hence, their application needs to be carefully balanced against the downstream effect on DBP formation.
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, Ministry of Education Key Laboratory of Yangtze River Water Environment, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China. Electronic address: feedwater@126.com.
authors.forename: Wenhai
authors.initials: W
authors.lastname: Chu
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, Ministry of Education Key Laboratory of Yangtze River Water Environment, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China; School of Environmental and Safety Engineering, Changzhou University, Changzhou, 213164, China.
authors.forename: Tengfei
authors.initials: T
authors.lastname: Chu
authors.affiliation: Department of Civil and Environmental Engineering, Imperial College London, London SW7 2AZ, UK.
authors.forename: Tom
authors.initials: T
authors.lastname: Bond
authors.affiliation: School of Environmental and Safety Engineering, Changzhou University, Changzhou, 213164, China.
authors.forename: Erdeng
authors.initials: E
authors.lastname: Du
authors.affiliation: School of Environmental and Safety Engineering, Changzhou University, Changzhou, 213164, China.
authors.forename: Yingqing
authors.initials: Y
authors.lastname: Guo
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, Ministry of Education Key Laboratory of Yangtze River Water Environment, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China. Electronic address: gaonaiyun@tongji.edu.cn.
authors.forename: Naiyun
authors.initials: N
authors.lastname: Gao
mesh_terms: D000097:Acetonitriles / Q000737:chemistry*; D002701:Chloramphenicol / Q000737:chemistry* / Q000302:isolation & purification; D002713:Chlorine / Q000737:chemistry; D004202:Disinfectants / Q000032:analysis / Q000737:chemistry; D004203:Disinfection / Q000379:methods; D054879:Halogenation; D006843:Hydrocarbons, Chlorinated / Q000737:chemistry; D008697:Methane / Q000031:analogs & derivatives* / Q000737:chemistry; D009595:Nitroparaffins / Q000737:chemistry*; D010084:Oxidation-Reduction / Q000528:radiation effects; D013440:Sulfides / Q000737:chemistry*; D013839:Thiamphenicol / Q000031:analogs & derivatives / Q000737:chemistry / Q000302:isolation & purification; D022882:Trihalomethanes / Q000737:chemistry*; D014466:Ultraviolet Rays; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000302:isolation & purification; D018508:Water Purification / Q000379:methods
chemical_list: D000097:Acetonitriles; D004202:Disinfectants; D006843:Hydrocarbons, Chlorinated; D009595:Nitroparaffins; D013440:Sulfides; D022882:Trihalomethanes; D014874:Water Pollutants, Chemical; C051552:persulfides; D002713:Chlorine; D002701:Chloramphenicol; C035534:florfenicol; D013839:Thiamphenicol; D008697:Methane; C008640:nitromethane
keywords: Chloramphenicols; Haloacetonitriles; Halonitromethanes; Trihalomethanes; Ultraviolet/persulfate