Design And Operation Of Landfill Leachate Treatment Process In Shahe Municipal Solid Waste Landfill Site

Landfill leachate is a typical high concentration of refractory organic polluted wastewater,characters of water quality of the leachate are shown as complex water quality,great harmfulness,high concentrations of COD,BOD and ammonia nitrogen and great changes of water quality.If not properly handled,it may cause serious pollution on the surrounding environment and groundwater.This paper combines the Shahe City Landfill leachate treatment engineering design.It summarizes the current situations of treatment technology of landfill leachate in China and abroad.It also combines the Shahe City Landfill leachate quality characteristics with the requirements of operability and economy of the treatment technology.So we determine adopting a “membrane bio-reactor（MBR）and nanofiltration（NF）and reverse osmosis（RO）” combined treatment process.The engineering design treatment capacity is 50m³·d-1.Several technical problems in the design of treatment engineering of landfill leachate are introduced.The engineering is mainly designed for the collection and treatment system of landfill leachate and the flow chart of “MBR+NF+RO” treatment process.The predicted result is analyzed.Finally the designed effluent quality reaches the firt class emission standard of“Control standard of domestic waste landfill pollution”（GB16889-2008）.Also,the project cost is reasonable analyzed to reduce economic investment to obtain good environmental benefits.The result of running and debugging shows: the removal rate of COD and NH³-N in MBR system can reach 85% and 92% respectively.The removal rate of COD in NF system can reach 90% and the effluent COD concentration is stable below 150mg·L^-1.The effluent COD concentration in RO system is further reduced and stable below 50mg·L^-1 to meet the emission standard.The removal rate of NH³-N in NF system is about 30% and the change of ammonia nitrogen between the inflow and outflow water is about 8mg·L^-1.Therefore,the NF system has no significant effect on the NH³-N.While the RO system has relatively obviously removing effect for NH³-N,the content of NH³-N of outflow water is about 5mg·L^-1.