Control of chlorination disinfection by-products in drinking water by combined nanofiltration process: A case study with trihalomethanes and haloacetic acids

Wenjing Zheng; Yan Chen; Jian Zhang; Xing Peng; Pengcheng Xu; Yalin Niu; Bingzhi Dong

doi:10.1016/j.chemosphere.2024.142121

Control of chlorination disinfection by-products in drinking water by combined nanofiltration process: A case study with trihalomethanes and haloacetic acids

Chemosphere. 2024 Apr 25:358:142121. doi: 10.1016/j.chemosphere.2024.142121. Online ahead of print.

Authors

Wenjing Zheng¹, Yan Chen², Jian Zhang¹, Xing Peng¹, Pengcheng Xu¹, Yalin Niu¹, Bingzhi Dong³

Affiliations

¹ Key Laboratory of Yellow River Water Environment in Gansu Province, Lanzhou Jiaotong University, Lanzhou, 730070, China; College of Environment and Municipal Engineering, Lanzhou Jiaotong University, Lanzhou, 730070, China.
² Key Laboratory of Yellow River Water Environment in Gansu Province, Lanzhou Jiaotong University, Lanzhou, 730070, China; College of Environment and Municipal Engineering, Lanzhou Jiaotong University, Lanzhou, 730070, China. Electronic address: xiaojingmama@163.com.
³ College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China; Key Laboratory of Yangtze River Water Environment, Ministry of Education, Shanghai, 200092, China.

PMID: 38677607
DOI: 10.1016/j.chemosphere.2024.142121

Abstract

Disinfection by-products (DBPs) are prevalent contaminants in drinking water and are primarily linked to issues regarding water quality. These contaminants have been associated with various adverse health effects. Among different treatment processes, nanofiltration (NF) has demonstrated superior performance in effectively reducing the levels of DBPs compared to conventional processes and ozone-biological activated carbon (O₃-BAC) processes. In this experiment, we systematically investigated the performance of three advanced membrane filtration treatment schemes, namely "sand filter + nanofiltration" (SF + NF), "sand filter + ozone-biological activated carbon + nanofiltration" (SF + O₃-BAC + NF), and "ultrafiltration + nanofiltration" (UF + NF), in terms of their ability to control disinfection by-product (DBP) formation in treated water, analyzed the source and fate of DBP precursors during chlorination, and elucidated the role of precursor molecular weight distribution during membrane filtration in relation to DBP formation potential (DBPFP). The results indicated that each treatment process reduced DBPFP, as measured by trihalomethane formation potential (THMFP) and haloacetic acid formation potential (HAAFP), with the SF + O₃-BAC + NF process being the most effective (14.27 μg/L and 14.88 μg/L), followed by the SF + NF process (21.04 μg/L and 16.29 μg/L) and the UF + NF process (26.26 μg/L and 21.75 μg/L). Tyrosine, tryptophan, and soluble microbial products were identified as the major DBP precursors during chlorination, with their fluorescence intensity decreasing gradually as water treatment progressed. Additionally, while large molecular weight organics (60-100,000 KDa) played a minor role in DBPFP, small molecular weight organics (0.2-5 KDa) were highlighted as key contributors to DBPFP, and medium molecular weight organics (5-60 KDa) could adhere to the membrane surface and reduce DBPFP. Based on these findings, the combined NF process can be reasonably selected for controlling DBP formation, with potential long-term benefits for human health.

Keywords: Combined nanofiltration process; Disinfection by-products; Drinking water treatment; Natural organic matter.