The Study About The Application Effect Of MBR+NF Leachate Combined Process In Xiaping Domestic Waste Landfill Site

At present, we generally deal with the municipal solid waste by burying. A lotof leachate generate during the filling process, which is long ignored, is threatening theenvironment. Then, collection and treatment of leachate effectively become an importantproblem in the world.Leachate mainly comes from rainfall and water produced by litter decomposition. Highconcentrations of pollutants, and the quality and quantity of the percolate change greatly aremain features in the leachate. The concentration of ammonia nitrogen increased gradually,biodegradability decreased, and the pollution time increasing, as a result, leachate becomesmore and more difficult to deal with.As the promulgation for new standard of leachate discharging, Standard for PollutionControl on the Landfill Site of Municipal Solid Waste (GB16889－2008), the treatment ofleachate has been more strict. At present the common seepage of leachatetreatment methods include: physical and chemical method, biological methodand wet method. Physichemical treatment Including adsorption method, chemicalprecipitation, membrane separation and so on, but this costs a lot, and has great effect inlow permeability of leachate treatment. Biological method is widely used in leachatetreatment, but often affected by shock load. It is generally used to treatlandfill leachate produced in the early stage. Wetland is a method using the naturalenvironment to change pollutants into nutrients of the landfill leachate under the artificialcontrol, wetland method has better effect, but can only deal with low concentration ofleachate, and requires a lot of land, so it is not feasible in reality.Now membrane treatment technology is the advanced treatment on Landfill Leachate athome and abroad, such as MBR、NF、RO and so on. Some of this technology has been usedin the actual operation, but sometimes effluent can not meet the new standards issues. Inorder to analysis of the influencing factors of MBR+NF process in practical application indepth, Xia Ping carried out experimental study of leachate treatment by this combinedsystem.XiaPing Domestic Waste Landfill Site in ShenZhen is the fist Solid waste landfill,which built by International sanitary landfill standards, and is classified as Demonstrationproject of national sanitary landfill. This landfill Primarily responsible for filling garbage in Luohu and Futian in ShenZhen. It will produce high concentrations of pollution in theprocess of litter decomposition and precipitation. If not treated timely, it will pollute thesurrounding environment.XiaPing constructed the landfill and leachate treatment station together. Which is usedto deal with leachate collected by layered drainage system. The scale is about1500t/d forwinter and summer2000t/d. In recent years, Xiaping improved wastewater treatmentstandards on the basis of landfill leachate treatment discharge within controlling index ofnational standard for a long time. It calls for leachate treatment of effluent to sites recycling.So, they plan to add advanced wastewater treatment systems when sewage can be treated tomeet secondary emission standards (MBR+NF).And the new systems can purify leachatefuther, and can raise the level of sewage treatment.Then,XiaPing will study on the newtechnology on the new effluent treatment process.At present, We use “ammonia stripping+Anaerobic Biofilter+A/O/O+MBR+NF” todeal with landfill leachate. This experiment mainly test chemical concentration of ammonianitrogen、COD、BOD influent and effluent of landfill leachate, analyze high concentrationsof pollutants removal efficiency of the new system in leachate treatment system. Accordingto test data analysis: COD、BOD and ammonia nitrogen removal rate amounted to98%,95%and99%.These results conform to meet design specifications, and the water can be used forroads, green watering and so on. It not only avoid secondary pollution of landfill leachate butalso improve the water environment of surrounding region. Furthermore, it provide a goodliving environment for the residents.Through the experimental, we study on treatment of leachate by MBR+NF combinedprocess, Analying the design and actual application effect of leachate treatment, trying toeliminate the influence of seasonal, and raise the improved and debugging method. Themain results include:1、There are the obvious effect of remove contaminants in leachate byMBR+NF system, and the effluent can meet the discharge standards.2、It has great effect ontreatment of MBR+NF combined system in differentseasons.3、The experiments shouldadjust the temperature and pH value according to the different processing stages to treatlandfill leachate effectively.4、Adjust treatment process timely, and the experiment provedthat adding two stage nitration reaction system and methanol can remove total nitrogeneffectively of leachateNow there is no mature skills or experience to treat hardly degradable landfill leachateat home and abroad. XiaPing will continue to study new leachate treatment technology，and try to do the experiment of recirculated leachateat at waste disposal filling site. In themeantime, they will research new technology to deal with hardly degradable landfill leachate, such as high oxidation technology、aged refuse disposal and so on. The key steps include:Laboratory studies, pilot test, Construction of demonstration projects, and then form into acertain technical standards. In the end, the technological achievement is being promoted toother domestic waste landfill, it has reference value and its practical significance for leachatetreatment in other landfills.