饮用水处理工艺中臭氧剂量控制消毒副产物生成势研究

Study of ozone dosage via disinfection by-product formation potential controlling in drinking water treatment

依托江苏某自来水厂预臭氧+常规处理+臭氧-BAC深度处理示范工程,在浑浊度、TOC、CODMn、UV254等常规评价指标监测基础上,重点探讨不同臭氧投加量条件下各处理单元对总三卤甲烷生成势(TTHMFP)与总卤乙酸生成势(THAAFP)各类消毒副产物生成势(DBPFP)物质的去除规律与作用机理。结果表明,在预臭氧最佳投加量为1.1 mg·L-1,后臭氧最佳投加量为1.8 mg·L-1时,预臭氧和臭氧-BAC深度处理单元对THMFP的去除以三氯甲烷生成势(TCMFP)为主,其去除量分别占TTHMFP去除量的86.8%和60.2%,对HAAFP的去除在预臭氧单元以三氯乙酸生成势(TCAAFP)为主,占THAAFP去除量的77.2%,在O3-BAC深度处理单元以氯代卤乙酸生成势(Cl-HAAFP)为主,占THAAFP去除量的70.2%。深度处理工艺不同工艺段在最佳臭氧投加剂量下对TTHMFP及THAAFP的平均去除率分别可达21.9%及63.2%,生物可降解溶解性有机碳(BDOC)总去除率达82.49%,说明该优化的深度处理工艺能够较有效地去除DBPFP,保障出水水质生物稳定性。

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.