title: Transformation of acetaminophen during water chlorination treatment: kinetics and transformation products identification.
abstract: As a high-consumption drug in the world, acetaminophen (AAP) has been widely detected in natural waters and wastewaters. Its reactivity and the transformation products formed during chlorination may greatly threaten the safety of drinking water. The reaction kinetics of AAP during chlorination was investigated in this study. The results showed that the reaction kinetics could be well described with a kinetics model of -d[AAP]/dt = k app[AAP]t (0.63)[Cl2]t (1.37). The values of apparent rate constant (k app) were dependent on reaction temperature, ammonium, and pH. With the increase in reaction temperature from 5.0 ± 1.0 to 40.0 ± 1.0 °C, the removal efficiency of AAP increased from 60 to 100 %. When ammonium was present in the solution at 2.0 mg/L, the transformation of AAP was inhibited due to the rapid formation of chloramines. The maximum of k app was 0.58 × 10(2) M(-1) · min(-1) at pH 9.0, and the minimum was 0.27 M(-1) · min(-1) at pH 11.0. A low mineralization of AAP (about 7.2 %) with chlorination was observed through TOC analysis, implying the formation of plenty of transformation products during chlorination. The main transformation products, hydroquinone and two kinds of chlorinated compounds, monochlorinated acetaminophen and dichlorinated acetaminophen, were detected in gas chromatography-mass spectrometry analysis.
authors.affiliation: School of Civil Engineering, Hefei University of Technology, Hefei, 230009, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Cao
authors.affiliation: School of Civil Engineering, Hefei University of Technology, Hefei, 230009, China.
authors.forename: Mengtao
authors.initials: M
authors.lastname: Zhang
authors.affiliation: School of Civil Engineering, Hefei University of Technology, Hefei, 230009, China. sjyuan@hfut.edu.cn.|State Key Laboratory of Pollution Control and Resource Reuse, Nanjing University, Nanjing, 210046, China. sjyuan@hfut.edu.cn.
authors.forename: Shoujun
authors.initials: S
authors.lastname: Yuan
authors.affiliation: School of Civil Engineering, Hefei University of Technology, Hefei, 230009, China.
authors.forename: Jingwei
authors.initials: J
authors.lastname: Feng
authors.affiliation: Chemistry Department, Delaware State University, Dover, DE, 19901, USA. qwang@desu.edu.
authors.forename: Qiquan
authors.initials: Q
authors.lastname: Wang
authors.affiliation: School of Civil Engineering, Hefei University of Technology, Hefei, 230009, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.affiliation: School of Civil Engineering, Hefei University of Technology, Hefei, 230009, China.
authors.forename: Zhenhu
authors.initials: Z
authors.lastname: Hu
mesh_terms: D000082:Acetaminophen / Q000032:analysis / Q000737:chemistry*; D002700:Chloramines / Q000737:chemistry; D002713:Chlorine / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry; D054879:Halogenation; D007700:Kinetics; D014867:Water / Q000737:chemistry*; D018508:Water Purification / Q000379:methods
chemical_list: D002700:Chloramines; D014867:Water; D000082:Acetaminophen; D002713:Chlorine
keywords: Acetaminophen; Chlorination; Kinetics; Mechanism; Transformation