Received Date:2024-07-18 Revised Date:2024-08-28
Nitrate and organic micropollutants (OMPs) often coexist in effluent from urban sewage treatment plants, while the influence of organic micropollutants on the advanced denitrification process remains unclear. To investigate how denitrification processes respond to organic micropollutants, this study constructed a denitrification moving bed biofilm reactor to examine the denitrification removal rate, organic micropollutant removal efficiency, response of extracellular polymeric substances (EPS) in the biofilm, and variation of key enzyme activities in the electron transport chain. Results showed that organic micropollutants limited denitrification efficiency, with carbon and nitrogen removal rates fluctuating and decreasing to below 70%. The removal rates of organic micropollutants such as ethinyl estradiol (EE), estriol (E3), and diclofenac (DCF) exceeded 75%, while carbamazepine (CBZ) removall rates fluctuated between 20% and 44%. When organic micropollutants were introduced, microorganisms initially utilized a portion of the EPS as nutrients and subsequently secreted more EPS to resist the stress caused by organic micropollutants. The activity of key enzymes in the electron transport chain was inhibited, thus reducing electron transport eliciency and deteriorating denitrification performance. Higher concentrations of organic micropollutants had a more pronounced impact on denitrification elfficiency, EPS content, and key enzyme activities in the electron transport chain, thereby leading to a quicker metabolic response from the microorganisms. The study provides a reference for deep nitrogen removal and co-removal of organic micropollutants in effluent.
Close-LIU Shuyi, WANG Depeng, HUANG Kailong, ZHANG Xuxiang. Study on the effects of organic micropollutants on advanced denitrification systems[J/OL]. Energy Environmental Protection: 1-8[2024-09-27]. https://doi.org/10.20078/j.eep.20240906.