FeCl3-生化耦合技术调控未知诱因的污泥膨胀

Control of Sludge Bulking Caused by Unknown Reason Through FeCl3 Coupled with Biochemical Methods

丝状菌污泥膨胀是影响污水处理厂出水水质的常见问题.现有的调控技术存在见效慢、耗时长和通用性差等弊端.提高COD和DO浓度,投加FeCl3和交替曝气是目前调控丝状菌膨胀的主要方法,这些方法的耦合技术调控未知诱因的污泥膨胀的效果鲜有报道.实验设计三段A/O反应器应急性运行SBR工艺,交替曝气时提高DO至(7.45±0.49)mg·L^-1,COD初始浓度提高至(332.73±106.06)mg·L^-1,沉淀工序中投加FeCl3,使之在混合液中质量浓度为120 mg·L^-1,形成的FeCl3-生化耦合技术快速调控未知诱因的Candidatus Saccharibacteria为主要菌属的污泥膨胀,污泥体积指数14 d从274 m L·g^-1稳定至56 m L·g^-1.FeCl3-生化耦合技术有效抑制Candidatus Saccharibacteria的繁殖,其属水平相对丰度从97.64%降低至32.67%.调控过程出水COD和PO43--P浓度均稳定达到一级A标准,NH4^+-N去除率从65.33%增长至74.65%.表明FeCl3-生化耦合技术调控未知诱因的污泥膨胀具有良好效果.

Filamentous bulking could commonly influence effluent water quality in sewage treatment plants.Existing technologies are slowly effective,time consuming,and poorly adaptable.For now,enhancing organics substrates(COD)and dissolved oxygen(DO)concentration,adding FeCl3 into the reactor,and maintaining alternant aeration conditions are common methods to control filamentous bulking,but the effects of coupling techniques on the control of bulking are rarely reported.In this study,the filamentous bulking resulting from unintentionally erupted Candidatus Saccharibacteria was controlled by FeCl3 coupled with biochemical methods,which transforming step-feed A/O processes to the SBR process in the emergency by increasing DO to(7.45±0.49)mg·L^-1 during aeration,enhancing COD to(332.73±106.06)mg·L^-1,and adding FeCl3 into the reactor to set the starting concentration to 120 mg·L-1.As the results showed,FeCl3 coupled with the biochemical method quickly counteracted the bulking sludge mainly composed of Candidatus Saccharibacteria caused by unknown reason,while the Sludge Volume Index dropped from 274 m L·g^-1 to 56 m L·g^-1 within 14 days.The relative abundance of Candidatus Saccharibacteria decreased from 97.64%to 32.67%at the genus level because FeCl3 coupled with the biochemical method inhibited growth of Candidatus Saccharibacteria.Meanwhile,effluents of both COD and PO4^3--P met the effluent requirements of the I-A discharge standard in China and removal efficiency of NH4^+-N increased from 65.33%to 74.65%.The results showed that FeCl3 coupled with the biochemical method exhibited good performance in the control of bulking caused by unknown reasons.