MBR出水氯、紫外、臭氧单独与组合消毒

Disinfection of MBR effluents by chlorination,ultraviolet irradiation,ozonation and combination technologies

采用氯、紫外和臭氧单独与2种组合工艺对MBR工艺中试出水进行了消毒实验,研究了不同消毒方式对指示性微生物的去除效果以及消毒副产物三卤甲烷(THMs)生成量随有效氯投加量的变化。结果表明,组合工艺消毒效果明显优于单独消毒效果,紫外剂量为25 mJ/cm2与有效氯投加量为3 mg/L的紫外与氯组合、臭氧投加量为6 mg/L与有效氯投加量为4 mg/L的臭氧与氯组合2种工艺消毒后出水中的总大肠菌群指标均满足《污水再生利用城市杂用水水质》(GB/T 18920-2002)的要求。THMs生成量随着有效氯投加量的增加而增加。相对紫外与氯组合消毒,臭氧与氯组合消毒可以大幅度降低THMs生成量,有效氯投加量为4 mg/L时,THMs生成浓度为14.11μg/L,比氯单独消毒过程降低了37.19%。

The objective of this work was to investigate the disinfection effectiveness of several technologies,i. e. chlorination,ultraviolet(UV) irradiation,ozonation,and the combination chlorination with UV irradiation or ozonation,on the removal of indicator microorganisms and the formation of trihalomethanes( THMs)related to available chlorine dosage from a pilot-scale MBR effluents. The combination technologies exhibited much higher disinfection effectiveness than that of single one. The total coliform of disinfected MBR effluents disinfected in both UV-chlorination combination process( at an UV dose of 25 mJ /cm2 and an available chlorine dose of 3 mg /L) and ozonation-chlorination combination process( at an ozone dose of 6 mg /L and an available chlorine dose of 4 mg /L) could meet the requirement of Reuse of Urban Recycling Water-Water Quality,a standard for Urban Miscellaneous Water Consumption(GB /T18920-2002). The concentration of THMs increased with the increase of available chlorine dosage. In comparison with UV-chlorination combination process,ozonation-chlorination combination process could effectively reduce the THM formation.. The concentration of THMs was 14. 11 μg /L at an available dose of 4 mg /L,which decreased by 37. 19% compared with chlorination disinfection.