title: Characterization and biotoxicity assessment of dissolved organic matter in RO concentrate from a municipal wastewater reclamation reverse osmosis system.
abstract: Reverse osmosis (RO) concentrate from municipal wastewater reclamation reverse osmosis (mWRRO) system containing organic compounds may associate with toxic risk, and its discharge might pose an environmental risk. To identify a basis for the selection of feasible technology in treating RO concentrates, the characteristics and biotoxicity of different fractions of dissolved organic matter (DOM) in RO concentrates from an mWRRO system were investigated. The results indicated that the hydrophilic neutrals (HIN), hydrophobic acids (HOA) and hydrophobic bases (HOB) accounted for 96% of the dissolved organic carbon (DOC) of the total DOM in the RO concentrate. According to the SEC chromatograph detected at 254 nm wavelength of UV, the DOM with molecular weight (MW) 1-3 kDa accounted for the majority of the basic and neutral fractions. The fluorescence spectra of the excitation emission matrix (EEM) indicated that most aromatic proteins, humic/fulvic acid-like and soluble microbial by-product-like substances existed in the fractions HOA and hydrophobic neutrals (HON). The genotoxicity and anti-estrogenic activity of the RO concentrate were 1795.6 ± 57.2 μg 4-NQOL(-1) and 2.19 ± 0.05 mg TAM L(-1), respectively. The HIN, HOA, and HOB contributed to the genotoxicity of the RO concentrate, and the HIN was with the highest genotoxic level of 1007.9 ± 94.8 μg 4-NQOL(-1). The HOA, HON, and HIN lead to the total anti-estrogenic activity of the RO concentrate, and HOA occupied approximately 60% of the total, which was 1.3 ± 0.17 mg TAM L(-1).
authors.affiliation: Department of Environmental Science and Engineering, Beijing Technology and Business University, Beijing 100048, PR China. Electronic address: sunyx@th.btbu.edu.cn.
authors.forename: Ying-Xue
authors.initials: YX
authors.lastname: Sun
authors.affiliation: Department of Environmental Science and Engineering, Beijing Technology and Business University, Beijing 100048, PR China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Gao
authors.affiliation: Environmental Simulation and Pollution Control State Key Joint Laboratory, State Environmental Protection Key Laboratory of Microorganism Application and Risk Control, School of Environment, Tsinghua University, Beijing 100084, PR China; Shenzhen Laboratory of Microorganism Application and Risk Control, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, PR China.
authors.forename: Hong-Ying
authors.initials: HY
authors.lastname: Hu
authors.affiliation: Environmental Simulation and Pollution Control State Key Joint Laboratory, State Environmental Protection Key Laboratory of Microorganism Application and Risk Control, School of Environment, Tsinghua University, Beijing 100084, PR China.
authors.forename: Fang
authors.initials: F
authors.lastname: Tang
authors.affiliation: Department of Environmental Science and Engineering, Beijing Technology and Business University, Beijing 100048, PR China.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Yang
mesh_terms: D057927:Hydrophobic and Hydrophilic Interactions; D009930:Organic Chemicals / Q000032:analysis / Q000633:toxicity*; D009995:Osmosis; D014865:Waste Disposal, Fluid; D062065:Wastewater / Q000032:analysis / Q000633:toxicity; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000633:toxicity*
chemical_list: D009930:Organic Chemicals; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: Anti-estrogenic activity; Dissolved organic matter fractions; Genotoxicity; Reverse osmosis concentrate; Wastewater reclamation