氯化钙控制污泥膨胀

Control of activated sudge bulking by adding calcium chloride

污泥膨胀是活性污泥工艺运行中经常遇到的最棘手的问题之一。本实验以人工合成污水为底物,采用序机式活性污泥法(SBR);研究投加无机混凝剂氯化钙控制污泥膨胀的情况,同时研究丝状菌和菌胶团的变化。研究发现,投加氯化钙后,丝状菌数量明显减少;形成较多大而密实规则的菌胶团,污泥膨胀得到控制。污泥容积指数(SVI)由最初的309.5 mL/g降到67.1 mL/g,污泥沉降性能改善。停止投加氯化钙后又运行了18周期,活性污泥没有发生再次膨胀。投加氯化钙对COD去除率没有明显影响。研究结果表明,投加氯化钙是一种有效的污泥膨胀应急控制措施。

The sludge bulking is one of the thorniest problems in the activated sludge process.The experiment used synthesis wastewater as the substrate,and operation process used sequencing batch reactor（SBR）.The effect of adding inorganic coagulant calcium chloride to control activated sludge bulking and the change of filamentous bacteria and the floc-forming bacteria was studied in a laboratory activated sludge system.The results showed that,after adding the calcium chloride,the number of filamentous bacteria obviously decreased;and the shape of zoogloea became larger and more roughly spherical,the sludge bulking was under control.The sludge volume index（SVI） decreased from 309.5 mL/g to 67.1 mL/g,the sludge settling property was improved.The system continued to run 18 cycles without adding the calcium chloride,the activated sludge did not bulking again.Adding calcium chloride had no significant effect on COD removal rate.The results indicated that adding calcium chloride was one kind of effective emergency methods to control sludge bulking.