絮凝剂对活性污泥降解有机物及除磷的影响

Effect of Flocculant on Organic Matter Degradation and Phosphorus Removal by Activated Sludge

为探究絮凝剂对污水生物除磷过程有机物降解及除磷的影响,以实际废水、聚合氯化铝(PAC)和聚丙烯酰胺(PAM)为探究对象,建立序批式强化生物除磷(EBPR)系统,在中温条件下研究了絮凝剂对EBPR系统的影响并能揭示相关作用机制。结果表明PAC与PAM存在能抑制化学需氧量(COD)去除,且两者同时存在时稳定时期出水COD为64~69 mg/L,相应去除效率为80.3%~81.5%,显著低于空白组。单独PAC与PAM对氨氮抑制不明显,而当PAC与PAM同时存在时,氨氮去除效率被显著抑制。絮凝剂提高污泥中胞外聚合物含量,且增加蛋白质与多糖的比例。此外,絮凝剂抑制生物除磷效率,PAC与PAM同时存在时,出水溶解性磷酸盐(SP)为1.68 mg/L,SP去除效率降低至79%。絮凝剂抑制厌氧释磷与好氧吸磷。絮凝剂降低除磷关键酶活性并降低Betaproteobacteria相对丰度而提高Alphaproteobacteria的相对丰度。

In order to explore the effect of flocculant on the degradation of organic matter and phosphorus removal in the process of biological phosphorus removal,a sequencing batch enhanced biological phosphorus removal(EBPR)system was established with the actual wastewater,polyaluminium chloride(PAC)and polyacrylamide(PAM).The results showed that the presence of PAC and PAM can inhibit the removal of chemical oxygen demand(COD),and when both of them exist at the same time,the COD of effluent in the stable period was 64~69 mg/L,and the corresponding removal efficiency was 80.3%~81.5%,which was significantly lower than that in the blank.When PAC and PAM exist at the same time,the removal efficiency of ammonia nitrogen was significantly inhibited.The flocculant increased the content of extracellular polymer and the ratio of protein to polysaccharide.In addition,when PAC and PAM exist at the same time,the SP of the effluent was 1.68 mg/L,and the SP removal efficiency was reduced to 79%.Flocculants inhibit anaerobic phosphorus release and aerobic phosphorus absorption.The flocculant decreased the activity of key enzyme and the relative abundance of Betaproteobacteria,while the relative abundance of Alphaproteobacteria increased.