Kinetics and mechanism of 17β-estradiol chlorination in a pilot-scale water distribution systems.
The kinetics and mechanisms of 17β-estradiol (E2) chlorination in water distribution systems (WDS) were studied. We examined the impacts of different factors, including pH, temperature, humic acid concentration and type, and flow velocity. The experimental results showed that the rate constants in beaker tests and WDS were described by a pseudo-first-order model. pH had the greatest impact on E2 chlorination in the beaker tests. However, temperature had the greatest impact on E2 chlorination in WDS. Mechanistic analysis of E2 chlorination showed that chlorine attacked E2 in three stages: 1) halogenation of the aromatic ring, 2) cleavage of the benzene moiety and chlorine or bromine substitution formation, and 3) formation of trihalomethanes (THMs) and halogenated acetic acids (HAAs) from phenolic intermediates through benzene ring opening with chlorine and/or bromine substitution of hydrogen on the carbon atoms. In the third stage, the concentrations of THMs and HAAs increased rapidly.
College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, Zhejiang 310027, China. Electronic address: congil@zju.edu.cn.
Cong
C
Li
College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, Zhejiang 310027, China.
Feilong
F
Dong
School of Civil and Environmental Engineering, Georgia Institute of Technology, USA. Electronic address: john.crittenden@ce.gatech.edu.
John C
JC
Crittenden
College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, Zhejiang 310027, China.
Feng
F
Luo
College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, Zhejiang 310027, China.
Xinbo
X
Chen
College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, Zhejiang 310027, China.
Taotao
T
Zhao
D000085:Acetates; D004958:Estradiol / Q000737:chemistry*; D054879:Halogenation; D006812:Humic Substances; D007700:Kinetics; D010865:Pilot Projects; D022882:Trihalomethanes; D018508:Water Purification / Q000379:methods*; D014881:Water Supply / Q000592:standards*
D000085:Acetates; D006812:Humic Substances; D022882:Trihalomethanes; D004958:Estradiol
17β-estradiol; Chlorination; Humic acid; Kinetics; Mechanism