Experimental Research On Two-stage Anaerobic System Treatment Of Incineration Leachate

Municipal solid waste incineration is a new trend of municipal solid waste treatment,it both accord with the requirement of the sustainable development of our country,and is suitable for the situation of the shortage of land resources and high population density in present in our country,while the treatment of leachate becomes a key problem.It is well known that leachate have the properties of high content of organic pollutants and complicated composition,high content of metal ions and NH3-N,low phosphorus content,and out of balance of nutrition proportion.There are also some pathogenic microorganisms and carcinogenic substances in leachate,which not only has a harmful effect on human health,and also cause pollution to the ecological environment.Therefore,leachate must be treated properly and effectively.In this paper,we studied on the two-stage anaerobic treatment of incineration leachate and based on the UASB reactor,analyzed the factors affecting the acidification,and the influence of process of granular sludge characteristics,which provide a reference for practical engineering of incineration leachate treatment.In this paper,we studied the two-stage anaerobic system treatment of incineration leachate.While influent COD concentration is 8946 ~ 57853 mg/L,VLR of first reactor is 8.78~15kgCOD/(m3·d),COD removal rate of first reactor is55.2~88.7%,VLR of second reactor is 2.11~4.64kgCOD/(m3·d),COD removal rate of second reactor is 46.2~87.5%,COD removal rate of two-stage UASB reactor reached 90.3~96.2%.While the two-stage of UASB reactor running in good condition,inflluent VFA concentration is 54~121mmol/L,effluent VFA concentration is2~3.5mmol/L.In the whole process,effluent pH value of first reactor is 7.2~8.6,effluent pH value of second reactor is 7.6~8.8.By analyzed the content of calcium and magnesium of influent and effluent,as well as the characteristics of granular sludge,we can draw the following conclusion.The calcium and magnesium content of influent is 79.17~89.16mmol/L,the calcium and magnesium content of effluent is 10.69~16.83mmol/L.Most of the calcium and magnesium accumulated in the first reactor,after 109 days,the calcium andmagnesium content of granular sludge in first reactor increased from 4.732mg/gSS to109.605mg/gSS,sludge activity decreased slightly than sludge in 78 day;the calcium and magnesium content of granular sludge in second reactor increased from4.169mg/gSS to 41.895mg/gSS,sludge activity unchanged essentially than sluge in78 day.The two-stage anaerobic system can restore high processing efficiency quickly from acidification by reduce the VLR and influent concentration.