由混凝或气浮构成的组合工艺处理太湖原水比较

Comparison of pilot effect between sedimentation and dissolved air flocculation for the treatment of Taihu Lake water

摘要:

针对低温东太湖原水,考察常规+臭氧-生物活性炭(O₃-BAC)处理中气浮和沉淀两种工艺对出水水质的影响．结果表明:气浮工艺对原水浊度的去除效果明显优于沉淀工艺,平均去除率高约10.1％,无论是气浮还是沉淀工艺,经O₃-BAC深度处理后出水浊度均稳定在1 NTU以下;气浮工艺对有机物的去除效果略优于沉淀工艺,CODMn和DOC平均去除率分别高约5.4％和1.6％,常规处理工艺后出水有机物含量不能达标,O₃-BAC工艺出水CODMn稳定在0.5～2.1 mg／L,DOC稳定在0.3～2.0 mg／L;沉淀／气浮工艺只对腐殖质略有去除效果,砂滤对荧光物质几乎无去除作用,而O₃-BAC工艺是去除水中荧光类物质的主要手段;气浮工艺对藻类的去除效果略优于沉淀工艺,深度处理后出水硅藻活性和叶绿素浓度降为0,蓝藻仍保有部分活性．

Abstract:

The effluent quality of combined process containing O₃-BAC treatment between sedimentation process and dissolved air flocculation(DAF) process for the treatment of East Taihu Lake raw water were compared. The results showed that the removal efficiency of turbidity by DAF was 10.1％ higher than that by sedimentation process, and the effluent turbidity was stabled at 1 NTU or less after the treatment of the O₃-BAC. Compared with the sedimentation process, the CODMnand DOC removal efficiencies of DAF were increased by 5.4％ and 1.6％, respectively. The CODMnand DOC were stabled at 0.5-2.1 mg／L and 0.3-2.0 mg／L after O₃-BAC process respectively, while the organic concentration could not reach to effluent standard after conventional treatment. O₃-BAC process played a dominant role in the decrease of fluorescence intensity, while conventional treatment process had only a slight or no effect on the removal of fluorescent material. The experimental results indicated that the DAF was slightly better for algae removal efficiency than sedimentation process. The concentration of diatom activity and chlorophyll decreased to 0 and cyanobacteria still retained part of the activity after advanced treatment.