Water quality of water source area in Taihu Lake and effect on water treatment process

Due to the severe pollution taken place in Taihu Lake, the investigation of water source quality in Taihu Lake is urgent for the development of drinking water treatment processes. Water samples taken from two water source areas in Taihu Lake were analyzed. The results showed that ammonia, TN, TP and COD_Mn were the dominant contaminants. The concentrations of those contaminants all exceeded “surface water environmental quality standards(GB3838-2002)” and seasonally varietied. Turbidity and density of algae displayed similar variation trends all year around and reached the peak values in July and August. In Xiaowanli water source area, the ratios of the dissolved organic substances(DOC) with molecular weights less than 0.5kD and those from 1kD to 3kD to total DOC were 27.92% and 28.37%, respectively. In Chongshan water source area, the ratios of those DOCs were 26.45% and 24.20% Nine classes of the US EPA Priority Pollutants were detected in the two areas. Based on the studied water source characteristics, the recommended drinking water treatment process is as follows: Cascade biological pre-treatment - (enhanced) conventional treatment process-O₃-BAC-disinfection.