Study On Sludge Reduction Under Synergistic Effect Of Diatomite And Uncoupling

Activated sludge is a sewage biological treatment technology which is most widely used in the world by far,but the biggest drawback of this process is to produce a lot of excess sludge.Common sludge disposal means accompanied by high cost,easy to cause secondary pollution and other issues.So the reduction of sludge is becoming the hot spots in field of water treatment.The sludge reduction technology is divided into three types:Recessive Growth,Biological Predation and Uncoupling.Among them,chemical uncoupling technology is recognized and praised for its convenience and no need to change the existing technology.However,the use of uncoupling agent alone can lead to reducing effluent treatment efficiency and deterioration of sludge performance.In this study,after seeking the best dosing concentration of DNP,DNP and diatomite were used to study the effect of sludge reduction,treatment,sludge and microbial population in SBR process.How to improve the treatment effect caused by DNP and the deterioration of sludge performance,and determine the optimal dosage method and best environmental impact factors of DNP and diatomite synergistic process.The experimental results show that in the SBR reactor,the sludge yield decreases with the increase of DNP(2,4-dinitropHenol)concentration,which is 80%higher than that of the blank.However,the effluent quality and the COD removal rate decreased by 7?30%,the removal rate of NH4+-N and TN decreased by 20%and 44%respectively,and SV1 was between 80-120mL/g,while the sludge activity increased by 21%.Through the cost analysis and the comparison of the parameters,the optimal dosage of DNP was 6mg/L.The optimum concentration of 6mg/LDNP was used in the SBR reactor in combination with 50mg/L diatomite,and the COD removal rate was improved by 13.35%compared with DNP(6mg/L)alone.NH4+-N and TN removal rates increased by 18.6%and 26.58%respectively,and SVI decreased by 13%.It was proved that diatomite could improve the effluent quality caused by DNP without affecting the effect of sludge reduction And sludge performance problems.By comparing the two DNP and diatomite synergistic method,it was found that Yobs decreased by 28.28%and 21%And sludge sedimentation had no significant effect.The temperature and pH value will have different effects on the parameters of the treatment system.By orthogonal test,we determined the temperature of 25? and pH value of 7 is the best environmental impact factor of the treatment system.