Developing surrogate indicators for predicting suppression of halophenols formation potential and abatement of estrogenic activity during ozonation of water and wastewater. (15th September 2019)

• Record Type: Journal Article
• Authors: Huang, Yu; Cheng, Shi; Wu, Ya-Ping; Wu, Ji; Li, Yan; Huo, Zong-Li; Wu, Ji-Chun; Xie, Xian-Chuan; Korshin, Gregory V.; Li, Ai-Min; Li, Wen-Tao
• Is Part Of: Water research. Volume 161(2019)
• Page Start: 152
• Page End: 160
• Publication Date: 2019-09-15
• Subjects: Ozonation -- Dissolved organic matter -- Halophenol -- Endocrine disrupting chemical -- Surrogate indicator -- Haloacetic acids; Water -- Pollution -- Research -- Periodicals; 363.7394
• DOI: 10.1016/j.watres.2019.05.092
• Languages: English
• ISSNs: 0043-1354

Abstract

Abstract: This study focused on developing surrogate indicators for predicting oxidation of phenolic groups in dissolved organic matter (DOM), suppression of halophenols' formation potential and abatement of estrogenic activity during ozonation of water and wastewater. The evolution of pH-dependent differential absorbance spectra suggests that O3 preferentially reacts with the DOM phenolic moieties and less so with the aromatic carboxylic groups with increasing O3 /DOC (dissolved organic carbon) ratios and changes of UV absorbance and fluorescence. When ozonation used as pretreatment, the formation of halophenols in subsequent chlorination decreased linearly with increasing O3 doses or changes of UV absorbance until it reached 85% suppression of the halophenols' formation from unaltered DOM. The thresholds of decreases of UVA254, UVA280 and humic-like fluorescence corresponding to 85% suppression of halophenols' formation were in the range of 25%–30%, 30%–35% and 30%–45%, respectively. Pre-ozonation also showed a moderate suppression of haloacetic acids (HAAs) formation potentials, ≤26.5% for reverse osmosis isolate of Suwannee River natural organic matter and ≤31.5% for Yangtze River at applied O3 doses. Measurement of changes of estrogenic activity during ozonation of water and wastewater showed that to attain a >90% abatement of estrogenic activity, the corresponding thresholds of decreases of UVA254, UVA280 and humic-like fluorescence were ∼30%, ∼40%, and ∼70%, respectively. Bromate formation was also suppressed to below 10 μg/L before these thresholds. This study suggests that optimal ozonation conditions and a balance between control of disinfection byproducts (halophenols, HAAs and bromate) and elimination of estrogenic activity can be reached based on online data. Graphical abstract: Image 1 Highlights: The pH-titration DAS reflected changes of DOM phenolic vs carboxylic groups by O3 . Pre-ozonation mildly controlled HAAs but effectively reduced halophenols formation. Suppression of halophenols (<85%) well correlated with O3 dose and UV absorbance. Abatement of estrogenic activity by ozonation lagged behind removal of EDCs. Thresholds of spectroscopic indices established for control of EDCs and DBPs by O3 .