Organic indicators and its influencing factors in finished water of domestic water treatment units with activated carbon filters in Shanghai

Objective To investigate organic indicators and its influencing factors in finished water of domestic water treatment units(WTUs) with activated carbon filters in Shanghai. Methods A total of 248 families were chosen in Shanghai and the finished water samples of WTUs were collected for the determination of COD and TOC in summer(Jul.),autumn(Oct.),and winter(Dec.), and the influencing factors were investigated. Results The unqualified rates for COD were 37.5% in summer,33.6% in autumn and 37.9% in winter. The unqualified rates for TOC of treated water was 0.8% in summer, meanwhile, TOCs were qualified in autumn and winter. Multivariate analysis showed that treated water volume of the filter was positively correlated with the unqualified rates of COD in summer, autumn and winter. There were positive correlations between COD and TOC in each season. Conclusion The main influencing factors for removal rate of organic compounds for domestic WTUs with activated carbon filters are treated water volume, the water quality of raw water. It is necessary to replace the activated carbon filters in time.