Occurrence and fate of N-nitrosamines in three full-scale drinking water treatment systems with different treatment trains
| Autor: | Zhenghua Zhang, Tahir Maqbool, Jiaxing Zhang, Li Chen, Yanling Qin, Qianye Li |
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| Rok vydání: | 2021 |
| Předmět: |
China
Risk level Nitrosamines Environmental Engineering 010504 meteorology & atmospheric sciences Distribution networks Chemistry Drinking Water Ultrafiltration 010501 environmental sciences 01 natural sciences Pollution Water Purification Residual chlorine Tap water Renal Dialysis Environmental chemistry Environmental Chemistry N nitrosamines Water treatment Cancer risk Waste Management and Disposal Water Pollutants Chemical 0105 earth and related environmental sciences |
| Zdroj: | Science of The Total Environment. 783:146982 |
| ISSN: | 0048-9697 |
| Popis: | The occurrence of mutagenic and carcinogenic N-nitrosamines in drinking water is of great concern. In this study, dynamics and removal of nine N-nitrosamines in three drinking water treatment systems of a southern city of China are monitored during one year of sampling. The impacts of physicochemical treatment units on the removal and generation of N-nitrosamines were evaluated. The O3 and KMnO4 based pre-oxidation units have caused an increase in N-nitrosamines concentration, with O3 showing the substantial generation of N-nitrosamines. The carbon filter and ultrafiltration membrane units were found effective in removing N-nitrosamine precursors. These drinking water treatment systems have been useful in removing N-nitrosamine precursors; meanwhile, a slight decrease was found in already formed N-nitrosamines concentration. However, N-nitrosomorpholine (NMOR) and N-nitrosodiphenylamine (NDPhA) were found resistant toward all kinds of physicochemical treatments, and negligible changes in concentration were noted in all drinking water treatment systems. The distribution networks in the city provided an effective contact period to residual chlorine and precursors, which caused an increase in N-nitrosamines concentration. Overall, N-nitrosodimethylamine (NDMA) and N-nitroso-diethylamine (NDEA) have been found near the cancer risk threshold (10-6) in all of the drinking water treatment systems, while the remaining seven N-nitrosamines were found below the risk level. |
| Databáze: | OpenAIRE |
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