低溶解氧丝状菌污泥微膨胀在A/O中的启动与维持

采用实际生活污水,研究了低溶解氧丝状菌污泥微膨胀在A/O系统中的启动、维持及其调控,并考察了微膨胀过程中系统对污染物的去除效果.试验结果表明:较低的有机负荷条件(F/M为0.14 kg/(kgMLSS.d))下,大幅度降低溶解氧并不一定会诱发污泥膨胀,而在正常有机负荷(F/M为0.24 kg/(kgMLSS.d))下,维持溶解氧质量浓度在0.3～0.4 mg/L时,系统的污泥容积指数(SVI)能稳定在150～300 mL/g,发生丝状菌微膨胀;丝状菌污泥微膨胀状态可长期稳定维持,并具有高度的可控性;与高溶解氧条件相比,在低溶解氧污泥微膨胀期间,COD和TN的平均去除率有所升高,分别为85%和69%,氨氮基本能完全硝化;同时,由于丝状菌的网捕作用,出水水质中的悬浮物(SS)明显减少,且随着SVI的升高而降低;A/O系统实现并维持低溶解氧丝状菌微膨胀期间,节约曝气量约42%,有效地节约了能耗.

Starting and Sustaining of Limited Filamentous Bulking Under Low Dissolved Oxygen in A/O Process

The starting,sustaining,and regulation of limited filamentous bulking with low dissolved oxygen and removal efficiencies of pollutants in the process are investigated based on a lab-scale A/O reactor with real domestic wastewater as the influent.Experimental results show that significant reduction of dissolved oxygen will not induce filamentous bulking with a lower organic load(F/M=0.14 kg/(kgMLSS·d));however,SVI values can be maintained at 150-300 mg/L with the normal organic load(F/M=0.24 kg/(kgMLSS·d)) when the dissolved oxygen is 0.3-0.4 mg/L.The state can also be sustained stable for long and have good controllability.Compared with the system under high dissolved oxygen,the removal efficiencies of COD and TN are improved during the period of limited filamentous bulking,and the values are 85% and 69%,respectively.Simultaneously,ammonia is completely removed.Besides,SS in the effluent decreases with increasing SVI.Aeration consumptions decrease by 17% during the period of limited filamentous bulking.Energy consumption can be effectively reduced.