title: Characterization of trihalomethane, haloacetic acid, and haloacetonitrile precursors in a seawater reverse osmosis system.
abstract: Seawater reverse osmosis (SWRO) has been extensively applied to replenish the limited freshwater resources. One concern of such technology is the formation of disinfection by-products (DBPs) during the pre-chlorination process. For the SWRO tested in this study, the concentrations of trihalomethanes (THMs), haloacetic acids (HAAs), and haloacetonitriles (HANs) increased by 35.1, 23.7 and 4.9μg/L, respectively, after a seawater sample (with UV254/DOC of 3.7L/mg·m and Br-of 50.9mg/L) was pre-chlorinated (1-2mg-Cl2/L). The dissolved organic matter (DOM) with molecular weight (MW) <1kDa dominated the formation of total THMs, HAAs and HANs. To further investigate DBPs precursors in the seawater, the DOM with MW<1kDa was fractionated to hydrophobic acids (HOA), hydrophobic bases (HOB), hydrophobic neutrals (HON), and hydrophilic substances (HIS). The excitation emission matrix fluorescence spectra analysis showed that most aromatic protein and fulvic acid of the DOM with MW<1kDa were present in the HON and HIS fractions. The HON fraction was the dominant precursor to form THMs and HAAs, while HIS controlled the formation of HANs. Furthermore, bromo - DBPs dominated the total DBPs yields after the chlorination of HIS fraction.
authors: Department of Environmental Science and Engineering, Beijing Technology and Business University, Beijing 100048, PR China.
authors: Zhe
authors: Z
authors: Yang
authors: Department of Environmental Science and Engineering, Beijing Technology and Business University, Beijing 100048, PR China. Electronic address: sunyx@th.btbu.edu.cn.
authors: Ying-Xue
authors: YX
authors: Sun
authors: Department of Civil and Environmental Engineering, The George Washington University, Washington, DC 20052, USA.
authors: Tao
authors: T
authors: Ye
authors: Department of Environmental Science and Engineering, Beijing Technology and Business University, Beijing 100048, PR China.
authors: Na
authors: N
authors: Shi
authors: State Key Joint Laboratory of Environmental Simulation and Pollution Control, State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (MARC), School of Environment, Tsinghua University, Beijing 100084, PR China.
authors: Fang
authors: F
authors: Tang
authors: State Key Joint Laboratory of Environmental Simulation and Pollution Control, State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (MARC), School of Environment, Tsinghua University, Beijing 100084, PR China.
authors: Hong-Ying
authors: HY
authors: Hu
keywords: Brominated disinfection by-products; Chlorination; Disinfection by-products precursors; Dissolved organic matter fractions; Seawater reverse osmosis (SWRO)