超滤/臭氧氧化工艺对再生水中AOC的去除效果

Removal of Assimilable Organic Carbon in Reclaimed Water by Ultrafiltration/Ozonation Process

如何控制微生物生长、保障水质生物稳定性,是再生水输配与利用过程中关注的重要问题。可同化有机碳(AOC)是评价水质生物稳定性的重要指标。对北京市某再生水厂超滤/臭氧氧化处理过程中AOC浓度及其分子质量分布特性的变化进行了研究,结果表明:二级出水中的AOC主要为分子质量>10 ku的有机物,超滤对二级出水中有机物的去除效果良好,对AOC的去除率达到73%。臭氧氧化可提高有机物的可生化性,导致AOC浓度升高了48%。在二级出水和超滤出水中,AOC物质以分子质量>10 ku的有机物为主,分别占79%和59%;经臭氧处理后,小分子质量(<1 ku)有机物对AOC的贡献明显上升,所占比例达到74%,同时大分子质量(>10 ku)和中等分子质量(1～10 ku)有机物所占的比例分别下降到22%和3%。

Control of microbial growth and biostability is important to the transportation, distribu- tion and use of reclaimed water. Assimilable organic carbon （AOC） is an important index to evaluate wa- ter biostability. The changes in AOC concentration and its molecular weight distribution in the ultrafiltra- tion/ozonation treatment process were investigated in a reclaimed water plant in Beijing. The results showed that the AOC in the secondary effluent was mainly composed of macromolecular organic com- pounds （more than 10 ku）. The removal rate of AOC in ultrafiltration was 73%. Ozonation could im- prove the biodegradability of organic matters in reclaimed water, resulting in a 48% increase in AOC.The proportions of AOCs with molecular weight more than 10 ku to total AOC were 79% and 59% in the secondary effluent and after uhrafihration, respectively. The proportion of AOCs with molecular weight less than 1 ku increased to as high as 74% after ozonation. Meanwhile, the proportions of AOC with mo- lecular weights of more than 10 ku and of 1 to 10 ku decreased to 22% and 3% respectively after ozona- tion.