This study is based on a demonstration project of pre-ozonation+conventional water treatment+ advanced treatment(O3-BAC) process in a drinking water treatment plant in Jiangsu province. Besides regular evaluation index examination such as turbidity

TOC

CODMn and UV254

this study focused on effects of ozone dosage on the removal efficiency of disinfection by-product formation potential (DBPFP)

mainly total trihalomethanes formation potential (TTHMFP) and total halogen acid formation potential (THAAFP) in each treatment unit. When the O3 dosages in the pre-ozone unit and O3-BAC unit were 1.1 mg·L-1 and 1.8 mg·L-1

respectively

trichloromethane chloroform formation potential (TCMFP) was the dominant THMFP species to be removed which account for 86.8% and 60.2%

respectively of TTHMFP removal mass. Trichloroacetic acid generating potential (TCAAFP) was the dominant THAAFP species to be removed in the pre-ozone unit which occupied an average of 77.2% of total THAAFP removal mass. In the O3-BAC treatment unit

chloride haloacetic acid formation potential (Cl-HAAFP) was the dominant HAAFP species to be removed and accounted for 70.2% of THAAFP removal mass. The optimized pre-ozonation+conventional water treatment+advanced treatment(O3-BAC) process finally removed up to 21.9% and 63.2% of TTHMFP and THAAFP

respectively

and obtained 82.49% of biodegradable dissolved organic carbon (BDOC) total removal rate. The result indicated that the advanced treatment under optimized condition would effectively remove the DBPFP contents

and thereby reduced the output of water DBPs and ensured the drinking water safety and its biological stability.