Insight into the effect of wastewater-derived dissolved organic matter composition on norgestrel degradation in activated sludge: Coupled bacterial community and molecular characteristics. (1st June 2022)

• Record Type: Journal Article
• Authors: Yu, Qingmiao; Hu, Xianda; Zhao, Fuzheng; Zhu, Chenyu; Guan, Linchang; Ren, Hongqiang; Geng, Jinju
• Is Part Of: Water research. Volume 216(2022)
• Publication Date: 2022-06-01
• Subjects: Activated sludge -- Norgestrel -- Degradation -- Bacterial community -- DOM composition; Water -- Pollution -- Research -- Periodicals; 363.7394
• DOI: 10.1016/j.watres.2022.118255
• Languages: English
• ISSNs: 0043-1354

Abstract

Highlights: DOM composition and NGT removal were measured in seventeen WWTPs during two seasons. Lab studies proved that DOM composition affected the NGT biodegradation by activated sludge. Dynamic variations of DOM molecular composition and bacterial communities were explored. Reveals the intrinsic relationship that the DOM molecules composition affected NGT degradation via regulation of microbes. Nine major TPs of NGT were identified with varied abundance in different groups. Abstract: Dissolved organic matter (DOM) mediates the microbial transformation of micropollutants, including norgestrel (NGT) in natural waters. However, little is known of the effect of complex and variable wastewater-derived DOM composition on NGT degradation during wastewater treatment. In this study, the relationship between the compositions of initial DOM and NGT removal efficiencies of 17 wastewater treatment plants (WWTPs) in spring and summer were analyzed. The different molecular composition of DOM was selected in the lab to further explore its effect on NGT degradation by activated sludge. Results indicated that the DOM composition was a substantial driver of NGT removal in WWTPs. The discrepancies in the initial DOM composition contributed to the differences in the kinetics of NGT degradation by activated sludge. The larger rapid decay phase rates of NGT are usually accompanied by a large proportion of labile substances in DOM. High-throughput sequencing and ultrahigh-resolution mass spectrometry were used to further analyze the evolution of bacterial communities and DOM molecular composition were combined with network analysis to reveal the intrinsic relationship that how DOM composition affected NGT degradation by regulating core microbes. Eighty-nine core OTUs were significantly associated with NGT degradation, and 73 occurred in the rapid decay phase, implying that NGT degradation was mainly regulated by the initial composition of DOM. Nine major transformation products were identified in different groups with widely varying concentrations or relative abundances of these transformation products. This work provides valuable insights into the effects of wastewater-derived DOM composition on NGT degradation by activated sludge and innovatively explores the influence mechanisms from the bacterial community and molecular characterization perspectives. Graphical abstract: Image, graphical abstract .