Pilot Study On MSW Transfer Station Leachate Treatment By Bio-regulation And Rapid Process Technology

Municipal solid waste (MSW) transfer station leachate has a comparative smallgeneration and scattered discharge, with the severe variety of quality. Transfer stationleachate has already become an important point source pollution of urban water bodyfor its high concentration of pollutants and intense odor. Lacking of collectioncondition and mature site treatment technology, transfer station leachate wasdischarged without control, especially for many medium and small size transferstations. Pilot research at site was carried out, aiming at transfer station leachateefficient and rapid treatment. Research achievements were listed below.Leachate quality and quantity of MSW transfer station was studied. For mediumand small size transfer stations, leachate is about5%~10%amount of MSWtransferred in the station at dry season and10%~20%at rainy season. COD ofleachate is7000mg/L~15000mg/L, with high color and SS concentration, oil canreach to over10000mg/L.The process of “bio-regulation–rapid process”, using for transfer stationleachate treatment was determined, according to the characteristic of leachate.Transfer station leachate anaerobic bio-regulation pool and rapid treatment equipmentbasing on “coagulation and sedimentation-Advanced Oxidation” were developed.Pilot scale experiment system was established at a transfer station site, with1.5t/ddispose ability. Pilot scale devices were run steady for over half a year. Systemoperation parameters were optimized. Anaerobic bio-regulation pool was run underroom temperature. When inflow COD was15000mg/L, HRT was3d, reductionefficiency was over60%. Oil reduced from over10000mg/L in the inflow to800mg/L.Bio-regulation pool was a good per-buffering treatment unit. The best operationparameters of rapid treatment equipment were:500mg/L of compound coagulant,0.06mol/L of Fe2+,H2O2/Fe2+=3：1, first pH=4, second pH=8. Union treatmentsystem was started and run steady in rainy season and dry season. Under the bestoperation parameters,“Bio-regulation and rapid process” can reduce COD from 15000mg/L in the inflow to about1000mg/L, oil reduce to50mg/L, color reductionefficiency was over95%. Turbid degree of effluent was only0.2NTU.This process not only reduces common pollutant effectively, but also has a goododor removal. Total reduced sulfur (TRS) was taken as index for odor treament.Anaerobic degradation was an important process of odor material generation, TRSincreased to4.167mg/L from0.602mg/L. Removal rate of odor material by rapidprocess was over95%, comparing to effluent of anaerobic treatment.The technology of “bio-regulation–rapid process” can be operated easily, with agood treatment effect. It solves problems of leachate treatment, including highconcentration of oganic pollutant, oil, and intense odor. This process achieves thegoal of leachate rapid, cheap and effective treatment at site.