[Variations of biological stability and disinfection byproduct in water distribution systems and their correlations]

Variations of assimilable organic carbon (AOC), trihalomethanes (THMs) and haloacetic acids (HAAs) in two different water distribution systems (DSs) were investigated in Shanghai, a eastern city of China. Correlations of drinking water biological stability and disinfection byproduct were analyzed. The results show that AOC and HAAs are varied based on chlorine residual and microbial activity. And their concentrations are increased by chlorine oxidation in the front part of pipe networks where high residual chlorine contents exist, while reduced by bacterial consuming in the end part pipe networks where low residual chlorine exists. Changes of THMs in DSs are influenced by residual chlorine merely, and contents have risen with the extension of pipe net. There are evident linear relationships between HAAs and AOC, and precursors of them are homologous. Contents of THMs are positively correlated with AOC. Therefore biological stability and disinfection byproduct, as two important factors of drinking water safety, present inherent relevances.