BAF用作混凝沉淀工艺预处理单元的研究

采用传统的混凝、沉淀、过滤工艺处理有机污染比较严重的城市河流原水时．出水水质难以令人满意，且混凝剂投量较高。为此，考察了曝气生物滤池（BAF）作为混凝、沉淀工艺预处理单元的可行性。研究结果表明，在投药量相同的情况下，BAF-混凝沉淀工艺出水的浊度和CODMn比单独混凝沉淀工艺低得多；由于BAF能导致水中有机污染物的成分（或性质）发生改变，因而提高了混凝沉淀工段的除污效果；组合工艺对CODMn的去除率〉70％，并有效降低了混凝剂的投量。

Study on Biological Aerated Filter as Pretreatment Process of Coagulation and Sedimentation

Using the conventional coagulation and sedimentation technologies,treated water quality cannot be guaranteed with higher coagulant consumption when treating urban river raw water with severe organic contamination.Therefore,the feasibility of the biological aerated filter(BAF) as the pretreatment unit of coagulation and sedimentation(CS) was investigated.The results indicate that under the same suitable coagulant doses,lower turbidity and COD_(Mn) concentrations are obtained from the effluent through the combined BAF-CS process.The COD_(Mn) removal rate of the combined process is above 70%,thus decreasing the coagulation dosage.Because BAF can cause change of composition of organic contaminants, the treatment effects in the subsequent coagulation and sedimentation system are enhanced.The coagulant consumption of the combined BAF-CS process is also lower than that of the traditional coagulation and sedimentation process.