The Effect of Leachate Resirculation on The Greenhouse Gases Emission from Municipal Solid Waste (MSW) Landfill in Tropical Climate Region

Abstract Indonesia is facing serious problem with huge amount of Municipal solid waste (MSW), whilst landfilling still the main option to dealing with it. The landfilling of the MSW is associate to the environmental issue, especially due to the leachate and landfill gas emissions. The leachate produces which is containing hazardous materials, while the landfill gas which mainly containing CO2 and CH4 that categorized as greenhouse gases. The leachate and landfill gas emissions were influenced by many factors, including climatic condition. This research was aimed to determine the effect of leachate recirculation on leachate production and landfill gas emissions of MSW landfill in tropical climate region. The experiment was carried out by using 2 landfill simulator reactors (LSRs) made of high density polyethylene (HDPE) pipe with 50 cm OD and 150 cm length. The sample used was collected from the Blang Bintang landfill, a regional landfill constructed to accept MSW from Banda Aceh municipality and Aceh Besar District. The LSRs were operated under difference operation mode, the first LSR were operate without leachate recirculation, however a certain amount of water was added to simulated the MSW landfill operated under conventional method. While the second LSR were operate with leachate recirculation to represent the MSW landfill operated under bioreactor landfill mode. Results of this study show the leachate recirculation has in significant affects on the rate of waste degradation and the landfill gas production. The highest CH4 concentration in landfill gas emission first and second LSRs were about 58% and 59%, respectively. This relatively small difference is probably due to the high rainfall in the tropics region. This results indicated that the potential of MSW landfill in tropical climate region as renewable energy, either operated under conventional or bioreactor landfills.