title: Comparison of micropollutants' removal performance between pre-ozonation and post-ozonation using a pilot study.
abstract: Despite the strong oxidizing ability of ozone, pre-ozonation has seldom been employed for the purpose of micropollutant removal in drinking water utilities. In this paper, the possibility of using pre-ozonation instead of post-ozonation for the removal of micropollutants was explored because of the lower risk of forming carcinogenic bromate. A 1.0 m3/h pilot system was utilized to compare the efficacy of pre- and post-ozonation in the removal of bulk organic pollutants as well as micropollutants, including typical odor-causing compounds, pharmaceuticals, and typical pesticides, from one source water (Huangpu River) characterized by the occurrence of various micropollutants. Both pre-ozonation and post-ozonation could achieve similar water purification performance under an ozone dose of 1.5 mg/L, in terms of bulk water quality parameters like CODMn(66% in combination with biological activated carbon (BAC) treatment, compared to 62% with the pre-ozonation-BAC combination) or micropollutants including 27 pharmaceuticals (85% in combination with BAC compared to 87% with the pre-ozonation-BAC combination) and 25 pesticides (72% in combination with BAC compared to 61% with the pre-ozonation-BAC combination). Pre-ozonation exhibited slightly better odorant removal performance (100% in combination with BAC compared to 92% with the post-ozonation-BAC combination); however, post-ozonation generated approximately 6.0 μg/L bromate at an ozone dose of 2.0 mg/L, while pre-ozonation did not form bromate even at an ozone dose as high as 3.0 mg/L. So pre-ozonation in combination with BAC might be a solution for the removal of micropollutants from source water with high bromate formation risk. The results of this study will be helpful for the optimization of ozonation processes in the water supply industry.
authors.affiliation: Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of the Chinese Academy of Sciences, Beijing 100019, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Yang
authors.affiliation: Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of the Chinese Academy of Sciences, Beijing 100019, China. Electronic address: jwyu@rcees.ac.cn.
authors.forename: Jianwei
authors.initials: J
authors.lastname: Yu
authors.affiliation: Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of the Chinese Academy of Sciences, Beijing 100019, China.
authors.forename: Qingyuan
authors.initials: Q
authors.lastname: Guo
authors.affiliation: Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of the Chinese Academy of Sciences, Beijing 100019, China.
authors.forename: Chunmiao
authors.initials: C
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of the Chinese Academy of Sciences, Beijing 100019, China.
authors.forename: Min
authors.initials: M
authors.lastname: Yang
authors.affiliation: Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of the Chinese Academy of Sciences, Beijing 100019, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Shanghai National Engineering Research Center of Urban Water Resources Co., Ltd., Shanghai 200082, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Xia
authors.affiliation: Shanghai National Engineering Research Center of Urban Water Resources Co., Ltd., Shanghai 200082, China.
authors.forename: Dong
authors.initials: D
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Yu
mesh_terms: D001959:Bromates; D010126:Ozone; D010865:Pilot Projects; D014874:Water Pollutants, Chemical; D018508:Water Purification; D014881:Water Supply
chemical_list: D001959:Bromates; D014874:Water Pollutants, Chemical; D010126:Ozone
keywords: Drinking water; Micropollutants; Post-ozonation; Pre-ozonation