Control Of Filamentous Bacteria Activatdd Sludge Expansion By The Weight Increasing Agent Method

With the continuous construction of sewage plants in China,the filamentous bulking of sludge is becoming more and more serious.In view of the present situation,the additive method can control sludge bulking rapidly and effectively.In the actual operation of waterworks,once the occurrence of sludge bulking,through this method can effectively and quickly control sludge expansion,to ensure the stable operation of sewage treatment.Thus,a large amount of time has been obtained to find the expansive factors causing sludge bulking.By improving the expansion factor,the environmental conditions for inhibiting filamentous bacteria growth have been created,and the sludge bulking problem has been fundamentally solved.In this study,artificial sewage was used as the substrate and SBR as the reactor.Filamentous sludge bulking occurred through 24 cycles by reducing dissolved oxygen?DO?and sludge loading.Study the control effect of filamentous sludge bulking by adding the Yellow River sand and zeolite powder in the small reactor.The results showed that adding the Yellow River sand and zeolite powder could control sludge bulking rapidly and effectively,and improve the settlement of sludge.when used repeatedly and equally way adding sand of the Yellow River to control sludge bulking,the best dosage is about 1000mg/L.After four cycles of operation,the SV was reduced to below 50%.In the effluent water,COD_Cr is about 45mg/L,ammonia nitrogen is about 4.5mg/L and total phosphorus is about 0.3mg/L,at the same time sludge bulking can be controlled.The optimum dosage is about 4200mg/L when using a large amount of one-time dosing method.After a cycle operation,the SV decreases rapidly,and the COD_Cr,ammonia nitrogen and total phosphorus respectively fluctuated from 30 to 40mg/L,4 to 6mg/L,and 0.3 to 0.4mg/L in the effluent water.In general,when adding the Yellow River sand control sludge bulking,there has little effect for COD_Cr and ammonia nitrogen,but it has a great influence on total phosphorus.Adding zeolite to control sludge bulking,when we using a large one-time dosing method to control sludge bulking,the optimal dosage is about4000mg/L.After running one cycle,the SV drops to about 40%.Because of the large surface area and strong adsorption which the zeolite powder has,the effluents of CODcr,total phosphorus and ammonia nitrogen are significantly lower than before.The effluent water quality of COD_Cr is about 40mg/L,the ammonia nitrogen is basically stable at about 2.5mg/L,and the total phosphorus is about 0.3mg/L.One-time dosing method has the advantages of convenient operation,remarkable effect,short duration and so on,so it is recommended to adopt a large number of one-time dosing method in actual operation.The bulking filamentous bacteria will not be completely eliminated by adding weight increasing agent.If the expansion factor is not improved,the sludge will expand again when the dosing factor is not improved.If timely changes of sludge bulking factor,the new sludge gradually can replace old sludge,The bulking filamentous bacteria will gradually disappear,and the sedimentation could be recovery.