Study On The Treatment Technology Of Later Landfill Leachate

Later landfill leachate which is of high concentration of organic matter and ammonia nitrogen and hard to be biodegraded, if not properly handled, can cause serious pollution to the surrounding water and soil, has become the key problems existing in the current MSW landfill. Taking the degradation of organic matter in later leachate as the main target, through the research of anaerobic biological process, aerobic biological process and advanced oxidation processes, to investigate the feasibility and effectiveness of the treatment of later landfill leachate.The results showed that:(1) It has obvious removal effect of COD to adopt aerobic biological treatment processing later landfill leachate, which states that later landfill leachate still contains lots of biodegradable organic matter. The results show when the aerobic biological system is under HRT of48h, gas water ratio of about100/1, the COD removal rate can reach more than45%, and the average concentration of COD varies from5344mg/1to2934mg/1; Ammonia nitrogen removal rate can reach more than60%, the average concentration of ammonia nitrogen varies from1264.4mg/1to502.8mg/1.(2) By adopting Fenton and micro-electrolysis method processing the waste water which has been processed by aerobic biological treatment, the COD removal rate can reach more than40%and20%, respectively. It states Fenton and micro-electrolysis method can oxidative part of refractory organic compounds in the waste water, and by comparison, Fenton method is better.(3) It has further removal effect of COD to adopt anoxic biological treatment processing the waste water which has been processed by aerobic-Fenton method, which states the anoxic denitrification can degrade part of refractory organic compounds in the waste water. The results show that after the anoxic denitrification, the COD removal rate can reach more than50%, and the average concentration of COD varies from1730mg/1to772mg/1.(4) On the basis of the above research, aerobic-Fenton-anoxic combined process is a kind of efficient treatment technology of later landfill leachate. The results show that the treatment efficiency of the process is good, the COD removal rate can reach more than85%, and the average concentration of COD varies from5344mg/1to772mg/1; Ammonia nitrogen removal rate can reach more than60%, the average concentration of ammonia nitrogen varies from1264.4mg/1to483.5mg/1.(5) Technical and economic analysis states that aerobic-Fenton-anoxic combined process for later landfill leachate has good COD treatment effect, the process flows are simple, operation and management is convenient. In addition, electric charge and chemicals cost of the process are 3.2and31.1yuan per ton, respectively. So the aerobic-Fenton-anoxic combined process is feasible in technology and economy.