Factors influencing DBPs occurrence in tap water of Jinhua Region in Zhejiang Province, China

Investigating the occurrence of disinfection by-products (DBPs) and identify the related influencing factors in drinking water is essentially important to control DBPs risk. In this study, 64 tap water samples were collected from 8 counties (or county level cities) in Jinhua Region of Zhejiang Province, China. Results showed that the median (range) of trihalomethane (THMs), haloacetic acids (HAAs), haloacetonitriles (HANs), haloketones (HKs) and halonitromethanes (HNMs) were 23.2 (9.1-40.9), 15.3 (5.8-38.6), 2.2 (0.7-7.6), 2.1 (0.2-6.4) and 0.7 (0.2-2.9) mu g/L, respectively. HAAs, HANs, HKs and HNMs levels were generally higher in summer than in winter or spring, while for THMs in most counties, higher levels occurred in winter than in summer or spring. Spatially, Yongkang, Yiwu and Dongyang had higher DBPs levels than Pujiang, Pan'an, Lanxi, Wuyi and Jinhua, which was generally consistent with their economy development (GDP). Correlation analysis showed that DBPs occurrence in tap water was significantly related with physicochemical parameters. Principle component analysis further suggested that organic matter (DOC and UVA(254)) are the major factors influencing the occurrence of THMs, HAAs, HANs and HKs in tap water, while for HNMs, both the organic (DOC and UVA(254)) and inorganic factors (e.g. Temp, NO2--N, pH, Br- and NH4+-N) played important role in its formation.