Simulation Test And Numerical Modeling Of Old Municipal Solid Waste Landfill In-situ Aeration

Sanitary landfill is one of the primary approaches for municipal solid waste?MSW?disposal and has been proved to be effective.Closure of landfill should be carried out when landfill reaches its final designed elevation or comes to the end of usage.However,landfill gas,leachate and malodor continue to impact the environment after the closure and the land cannot be effectively utilized before it meets Land Use Standard.Apart from these sanitary landfill,there are numerous scattered garbage fills,garbage ditches,and simple landfill sites,most of which are equipped with no anti-seepage system,landfill gas and leachate collection and treatment system.They may cause potential contamination to the environment.Hence,plenty of accelerated stabilization technology emerged so as to control the contamination,shorten the time for landfill stabilization.In situ aerobic remediation is one of the sort and was conducted here in the laboratory scale to study pollution degradation of landfill under aerated condition.Contents and results:?1?In situ aeration landfill simulation reactor was designed with auto control system which was capable of monitoring temperature,water content and oxygen concentration constantly.Water content and oxygen concentration were regulated by pump and air compressor through the feedback adjustment parameters from auto control system.?2?Through aeration intensity experiment and water content experiment,it was found that the field capacity of the three years old landfill was 38%while the aeration efficiency decreased when the oxygen concentration beyond 20%and the aerobe activity restrained below 13.5%?3?After 285 days intermittent aeration,VS,BDM and cellulose,which were considered as the characterization index of landfill,had been biodegraded by 45.7%,63.4%and 42.9%,while COD,BOD,NH₃-N and TN,which were considered as the characterization index of leachate,had been biodegraded by 77.1%,91.4%,98.6%and 65.2%.?4?According to the experimental data,landfill biodegradation was fitted well by first order hydrolysis model,and leachate biodegradation was fitted well by Monod model too.The characterization index of landfill and leachate are analyzed by Spearman rank correlation,BDM had the best correlation with the other landfill characterization index,while BOD had the best correlation with the other leachate characterization index.