title: Comparison of formation of disinfection by-products by chlorination and ozonation of wastewater effluents and their toxicity to Daphnia magna.
abstract: This study compared the two most frequently used disinfectants (i.e., chlorine and ozone) to understand their efficiency in wastewater effluents and the ecotoxicity of disinfection by-products created during chlorination and ozonation. Four trihalomethanes (THMs) and nine haloacetic acids (HAAs) were measured from a chlorine-disinfected sample and two aldehydes (i.e., formaldehydes and acetaldehydes) were analyzed after ozonation. Chlorination was effective for total coliform removal with Ct value in the range of 30-60 mg-min/L. Over 1.6 mg/L of ozone dose and 0.5 min of the contact time presented sufficient disinfection efficiency. The concentration of THMs increased with longer contact time (24 h), but that of HAAs showed little change with contact time. The measured concentration of formaldehyde at the ozone dose of 1.6 mg/L and the contact time of 9 min showed the greatest value in this study, approximately 330 μg L(-1), from which the corresponding ecotoxicity was determined using an indicator species, Daphnia magna. The ecotoxicity results were consistent with the toxicological features judged by occurrence, genotoxicity, and carcinogenicity. Both the disinfection efficiency as well as the DBP formation potential should therefore be considered to avoid harmful impacts on aquatic environments when a disinfection method is used for wastewater effluents.
authors.affiliation: Department of Environmental Engineering, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul, 05029, South Korea.
authors.forename: Keun-Young
authors.initials: KY
authors.lastname: Park
authors.affiliation: Department of Environmental Engineering, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul, 05029, South Korea.
authors.forename: Su-Young
authors.initials: SY
authors.lastname: Choi
authors.affiliation: Department of Environmental Engineering, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul, 05029, South Korea; Youngsin Metal Industrial Co., LTD., Electricity Business Division, 593 Manho-ri, Poseung-myun, Pyongtaek-si, Kyunggi-do, South Korea.
authors.forename: Seung-Hoon
authors.initials: SH
authors.lastname: Lee
authors.affiliation: Department of Environmental Engineering, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul, 05029, South Korea. Electronic address: jhkweon@konkuk.ac.kr.
authors.forename: Ji-Hyang
authors.initials: JH
authors.lastname: Kweon
authors.affiliation: Department of Civil and Environmental Engineering, Sejong University, 209 Neungdong-ro, Gwangjin-gu, Seoul, 05006, South Korea.
authors.forename: Ji-Hyeon
authors.initials: JH
authors.lastname: Song
mesh_terms: D000079:Acetaldehyde / Q000032:analysis / Q000633:toxicity; D000818:Animals; D002713:Chlorine / Q000737:chemistry* / Q000633:toxicity; D062845:Chloroacetates / Q000032:analysis / Q000633:toxicity; D003621:Daphnia / Q000187:drug effects*; D004202:Disinfectants / Q000737:chemistry* / Q000633:toxicity; D004203:Disinfection / Q000379:methods*; D005557:Formaldehyde / Q000032:analysis / Q000633:toxicity; D054879:Halogenation; D010126:Ozone / Q000737:chemistry* / Q000633:toxicity; D022882:Trihalomethanes / Q000032:analysis / Q000633:toxicity; D062065:Wastewater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000633:toxicity; D018508:Water Purification / Q000379:methods
chemical_list: D000079:Acetaldehyde; D002713:Chlorine; D062845:Chloroacetates; D004202:Disinfectants; D005557:Formaldehyde; D010126:Ozone; D022882:Trihalomethanes; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: Chlorination; Disinfection by-products; Ecotoxicity; Ozonation; Wastewater effluents