Study On Landfill Leachate Treatment By Biological Contact Oxidation And Electrocoagulation

Landfill leachate forms in trash handling by some complex effects, such as trash decomposition, raining, surface water and liquid wastes. The COD or BOD5 value of landfill leachate can achieve above 10000mg/L, and NH4-N value can be above 400mg/L, which cause serious pollution. Landfill leachate moving water will result in much environmental pollution.It is difficult to treat Landfill leachate with low expenses. The treatment process of landfill leachate in China is in primary stage. The research orientation of wastewater treatment is to treat landfill leachate economically and effectually. It is not easy to dispose landfill leachate by singular method to achieve discharging criterion; therefore, how to apply complex process to teat landfill leachate becomes a hot spot.The research object in this paper was the landfill leachate of Changchun Peijia Site. The feasibility and water quality changing rule in treating by biological contact oxidization and Electrocoagulation were studied. It showed that this process was applicable, effective and can provide test basis on future engineering and researches.On the basis of summarizing and discussing landfill leachate treatment method and other experiments (anaeration-biological contact oxidization; electrocoagulation), biological contact oxidization and electro-coagulation was chosen to treat landfill leachate in this paper.Fresh pig dung was chosen for the source of inoculating sludge to train microorganism in biological contact oxidization system. During the training, hydraulic loading was adjusted in turns from 5 L/d to 10L/and to15 L/d. After 15-day training biological contact oxidation system can run normally. In this stage, the removal rate of COD and NH4-N were all above 50%, the maximalremoval rate of COD was 68. 59%, and the maximal removal rate of NH4-N was 54. 01%.The relevant factors were analyzed and the optimum condition was achievedin electrocoagulation experiment. The relevant conditions were electrodematerial, water pH, reaction time T, electric current intensity I, anddistance between two electrode d. The major conditions were d, I and T. Theoptimum condition was that d=20mm, T=30min, I=3A, electrode material was iron.The removal rate of COD was 84. 63%, the removal rate of NH4-N was 86. 13% by biological contact oxidization and electrocoagulation complexprocesss The water quality can apply landfill leachate second-leveldischarging criterion.The innovation of this paper lied in: ?biological contact oxidization and electrocoagulation complex process was first used to treat landfill leachate ; ?only two-stage process used to treat landfill leachate cound satisfied the second-level discharge criterion.With the rapid development of economic, the quality of trash and landfill leachate are rapidly increasing, with water resource continuously shortage and public environment consciousnesss increasing, people need more higher water quality. In conclusion, this paper provided concrete operational method for our landfill leachate treatmemt, and can achieve goodenvironmental and social benefits.