title: Transformation of anti-estrogenic-activity related dissolved organic matter in secondary effluents during ozonation.
abstract: Anti-estrogenic activity of dissolved organic matter (DOM) in reclaimed water is gaining increasing attention. In this study, anti-estrogenic activity removal efficiency by ozonation in the tertiary treatment process of domestic wastewater was investigated. The anti-estrogenic activity in the secondary effluents used in this study ranged between 0.95 and 2.00 mg-TAM L(-1) and decreased significantly after ozonation. The removal efficiency of anti-estrogenic activity at a dose of 10 mg-O3 L(-1) was 65-87%. The removal of the anti-estrogenic activity was highly correlated with the removal of UV254, suggesting that UV254 can be used as a surrogate for anti-estrogenic activity during ozonation. The results of size exclusion chromatography of the wastewater samples during ozonation showed that the UV254 absorbance of the DOM fraction with large apparent molecular weight (MW) around 7.6 k Da dropped significantly, and the DOM fraction was suspected to be humic substances which have been previously identified as anti-estrogenic constituents in secondary effluents. The excitation emission matrix fluorescence spectra of the wastewater samples proved that humic substances existed in the DOM and indeed reacted with the ozone. With the help of two-dimensional correlation of Fourier transform infrared, it was confirmed that the aromatic structures in the DOM were largely destroyed by ozonation. Therefore, it was suggested that the destruction of the aromatic structures in the DOM was related to the removal of the anti-estrogenic activity.
authors.affiliation: Environmental Simulation and Pollution Control State Key Joint Laboratory, and State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (MARC), School of Environment, Tsinghua University, Beijing 100084, PR China. Electronic address: tangx05@mails.tsinghua.edu.cn.
authors.forename: Xin
authors.initials: X
authors.lastname: Tang
authors.forename: Qian-Yuan
authors.initials: QY
authors.lastname: Wu
authors.forename: Xin
authors.initials: X
authors.lastname: Zhao
authors.forename: Ye
authors.initials: Y
authors.lastname: Du
authors.forename: Huang
authors.initials: H
authors.lastname: Huang
authors.forename: Xiao-Lei
authors.initials: XL
authors.lastname: Shi
authors.forename: Hong-Ying
authors.initials: HY
authors.lastname: Hu
mesh_terms: D002850:Chromatography, Gel; D020847:Estrogen Receptor Modulators / Q000737:chemistry*; D010126:Ozone / Q000737:chemistry*; D012995:Solubility; D013050:Spectrometry, Fluorescence; D017550:Spectroscopy, Fourier Transform Infrared; D060753:Water Quality
chemical_list: D020847:Estrogen Receptor Modulators; D010126:Ozone
keywords: 2D correlation analysis of FTIR; Anti-estrogenic activity; Fluorescence analysis; Ozonation; Size exclusion analysis