Characterization of DOM and disinfection by-products precursors in biological activated carbon filter backwash water from drinking water treatments
Tianxiao Sun,
Yulin Tang,
Xinlu Qu,
Yongjie Huang,
TuoDong Liu,
Bin Xu,
Haihua Tang,
Tianyang Zhang,
Naiyun Gao
Affiliations
Tianxiao Sun
State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science & Engineering, Tongji University, Shanghai 200092, China
Yulin Tang
State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science & Engineering, Tongji University, Shanghai 200092, China
Xinlu Qu
State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science & Engineering, Tongji University, Shanghai 200092, China
Yongjie Huang
State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science & Engineering, Tongji University, Shanghai 200092, China
TuoDong Liu
State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science & Engineering, Tongji University, Shanghai 200092, China
Bin Xu
State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science & Engineering, Tongji University, Shanghai 200092, China
Haihua Tang
Shanghai Waterworks Fengxian Co., Ltd, Shanghai 201400, China
Tianyang Zhang
State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science & Engineering, Tongji University, Shanghai 200092, China
Naiyun Gao
State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science & Engineering, Tongji University, Shanghai 200092, China
Biological activated carbon filter backwash water (BAC FBW) removes pollutants from BAC filters in drinking water treatment plants. Characterizing the dissolved organic matter (DOM) in BAC FBW is of great significance for the recycling and treatment of backwash water. DOM pollution was monitored over a year using three-dimensional excitation–emission matrix fluorescence spectra. The dissolved organic carbon (DOC) concentration and fluorescence results showed that the DOC concentration reached the lowest value of 1.95 mg/L in the summer. The relative abundances of fluorescence components had a direct relationship with temperature variations. The soluble microbial products were enhanced greatly during cold seasons, while fulvic-acid-like and humic-acid-like compounds remained constant. Disinfection by-products (DBPs) formation potential and cytotoxicity were evaluated. The total haloacetonitriles (HANs), trihalomethanes (THMs), halonitromethanes (HNMs), and haloacetaldehyde (HALs) formation potentials ranged from 35.5 to 47.3 μg/L, 95.1 to 126 μg/L, 4.95 to 8.06 μg/L, and 43.4 to 53.0 μg/L in BAC FBW, respectively. Among all DBPs included in the calculation, the order of contribution to cytotoxicity was HANs > HALs > THMs > HNMs, respectively. Especially, HANs were much higher than the other DBPs, which should be controlled to avoid the biological risk of effluent quality. HIGHLIGHTS DOC concentration of backwash water reached its lowest value in the summer.; Seasonal variations impacted the composition of DOM due to microbial activity.; THMs were the main DBPs in the backwash water.; The order of contribution to cytotoxicity was HANs > HALS > THMs > HNMs in backwash water.;
