臭氧接触池臭氧投加方式的优化

摘要

臭氧接触池内臭氧(O3)投加方式是影响臭氧接触池反应效率的关键因素.以密云水库水为处理对象,对臭氧接触池内臭氧投加方式进行优化,通过考察气液接触方式和投加点个数对ρ(O3)、传质效率及有机物去除率的影响,确定最优臭氧投加方式.结果表明,适当增加布气点个数可有效增强气液传质,提高有机物去除率,但当布气点个数高于3个时,臭氧传质效率无明显提升,而且造成出水ρ(O3)过高,不利于后续工艺的进行.采用三段式臭氧投加方式,臭氧投加比为3∶3∶1时,密云水库水中臭氧传质效率达78.1％,有机物去除率为47.5％；向密云水库水中添加3 mg/L腐殖酸后,该投加比下臭氧传质效率为76.8％,有机物去除率为40.3％,出水ρ(O3)为0.26 mg/L,不会对后续工艺产生影响；并且该条件下臭氧利用率最高,BrO3-生成量最低,为最佳臭氧投加比.%The pollution of surface water is becoming more and more serious with the economic development.The requirements for the drinking water quality was higher than before since the "Standards for Drinking Water Quality" (GB/T 5749-2006) was implemented.In order to remove the organic pollutants,ozonation was employed as a tool in the drinking water treatment process,and the ozone contactor was used to make ozone diffused into the water.The ozone distribution is a key factor to the reaction efficiency between ozone and the organic pollutant in ozone contactor.The influence of ozone distribution in the ozone contactor on mass transfer efficiency,O3 content and organic removal efficiency was investigated,while water samples were collected from the Miyun Reservoir.The gas-liquid mass transfer was enhanced,and the removal efficiency of organic pollutant was improved when the number of aeration point increased.However,the mass transfer efficiency of ozone showed no significant increase when four-point aeration was used.Moreover,O3 content in the effluent water was too high for the following process.The mass transfer efficiency of ozone in the water was 78.1％,and the removal efficiency of oganics was 47.5％ when three-point aeration was used,with the proportion of 3∶ 3∶ 1.When humic acid of 3 mg/L was added in the water samples,the mass transfer efficiency of ozone was 76.8％,and the removal efficiency of oganics was 40.3％ using the same method.The O3 content in the effluent water was 0.26 mg/L,which would not destroy the biofilm on the surface of the activated carbon in biological activated carbon progress.At the proportion of 3∶ 3∶ 1,the utilization ratio of ozone value was the highest (60.1％),and the generation amount of bromate was the lowest.Therefore,the best method of gas distribution in ozone contactor was three-point aeration,with the proportion of 3∶ 3∶ 1.