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) µg/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 UVA254) are the major factors influencing the occurrence of THMs, HAAs, HANs and HKs in tap water, while for HNMs, both the organic (DOC and UVA254) and inorganic factors (e.g. Temp, NO2--N, pH, Br- and NH4+-N) played important role in its formation.

Using regression models to evaluate the formation of trihalomethanes and haloacetonitriles via chlorination of source water with low SUVA values in the Yangtze River Delta region, China.

The purpose of this study was to develop the multiple regression models to evaluate the formation of trihalomethanes (THMs) and haloacetonitriles (HANs) during chlorination of source water with low specific ultraviolet absorbance (SUVA) in Yangtze River Delta, China. The results showed that the regression models of THMs exhibited good accuracy and precision, and 86-97 % of the calculated values fell within ±25 % of the measured values. While the HANs models showed relatively weak evaluation ability, as only 75-83 % of the calculated values were within ±25 % of the measured values. The organic matter [dissolved organic carbon (DOC) or UV absorbance at 254 nm] and bromide exerted the most important influence on the formation of HANs. While for THMs, besides the organic matter and bromide, reaction time was also a key factor. Comparing the models for total THMs (T-THMs) in this study with others revealed that the regression models from the low SUVA waters may have low DOC coefficients, but high bromide coefficients as compared with those from the high SUVA waters.