Study on Acceleration of Old Landfill Stabilization by Using In Situ Aerobic Landfill Method Combined with Leachate Recirculation

摘要

Landfilling is a popular solid waste disposal method because of low financial costs, but it is potential health risk to both surrounding ecosystems and human population. Conventional landfill sites usually require long-term and scientific management to mitigate any possible environmental damage. Especially, old landfill sites might require aftercare for decades or even centuries, and in some cases, to remediate or accelerate stabilization of old landfill is very necessary. So a field experiment system with in situ aerobic landfill combined with leachate recirculation was constructed and operated in natural condition at an existing landfill in Beijing to observe the effects of leachate recirculation and air injection on old landfill stabilization. Samples of leachate and landfill solid waste were collected and analyzed before and after the start of experiment system. The moisture content, dry density and volatile solid (VS) of solid waste were measured, and the pH and dissolved total organic carbon (DTOC) of lixivium of solid waste were also measured. At the same time, some evaluation parameters of leachate were measured, such as pH, specific conductance, solid content, CODcr, TOC, NH3-N,metal ion and chlorine ion, and so on. The result of experiment indicated that old landfill stabilization was accelerated by using leachate recirculation system and air injection system.