Quantification of methane and carbon dioxide emissions from an active landfill: study the effect of surface conditions on emissions

Global warming is one of the principal environmental crises, and landfills are regarded as leading sources of greenhouse gases, mainly methane (CH 4 ) and carbon dioxide (CO 2 ). The present study aimed to quantify the CH 4 and CO 2 emissions from an open, active municipal solid waste (MSW) dumpsite, which has been functioning for over 30 years in Karadiyana, Sri Lanka. The effect of surface conditions such as moisture content, organic content, pH, surface temperature, vegetation growth, and waste disposal history on emissions was studied using geostatistical analysis. Based on the surface physical conditions and waste disposal history, multiple samplings were done from eight identified cells. The superficial emission rate was determined using the static closed flux chamber method. Results showed that the average emission rates of CH 4 and CO 2 were 10,672 and 40,827 mg m −2 h −1 , and total emissions were 7,436 and 21,653 kg d −1 , respectively. Further, the highest fraction of the total was from the old mixed waste area (CH 4 ; 26% and CO 2 ; 35%), which was filled with water, and the highest flux rates were reported in trenches where leachate flows showing a significant pathway to migrate landfill gases to the atmosphere (CH 4 ; 37,410 and CO 2 ; 140,158 mg m −2 h −1 ). Moreover, moisture and organic matter content positively correlate with CH 4 flux rates. Results concluded that the proper drainage system on the dump and a leachate treatment system with gas collecting and purification method would reduce the considerable amount of methane emission from open MSW dumpsites.