Solid waste characteristics and their relationship to gas production in tropical landfill C. Chiemchaisri & W. Chiemchaisri & Sunil Kumar & J. P. A. Hettiaratchi Received: 26 June 2006 / Accepted: 15 November 2006 / Published online: 26 April 2007 # Springer Science + Business Media B.V. 2007 Abstract Solid waste characteristics and landfill gas emission rate in tropical landfill was investigated in this study. The experiment was conducted at a pilot landfill cell in Thailand where fresh and two-year-old wastes in the cell were characterized at various depths of 1.5, 3, 4.5 and 6 m. Incoming solid wastes to the landfill were mainly composed of plastic and foam (24.05%). Other major components were food wastes (16.8%) and paper (13.3%). The determination of material components in disposed wastes has shown that the major identifiable components in the wastes were plastic and foam which are resistant to biodeg- radation. The density of solid waste increased along the depth of the landfill from 240 kg m -3 at the top to 1,260 kg m -3 at the bottom. Reduction of volatile solids content in waste samples along the depth of landfill suggests that biodegradation of solid waste has taken place to a greater extent at the bottom of the landfill. Gas production rates obtained from anaerobic batch experiment were in agreement with field measurements showing that the rates increased along the depth of the landfill cell. They were found in range between 0.05 and 0.89 l kg -1 volatile solids day -1 . Average emission rate of methane through the final cover soil layer was estimated as 23.95 g -2 day -1 and 1.17 g -2 day -1 during the dry and rainy seasons, respectively. Keywords Gas production . Landfill gas . Methane emission . Tropical climate . Waste characteristics Introduction Landfill gas created from decomposition processes of solid wastes is mainly composed of methane and carbon dioxide. A wide range of gas production rates of between 0.187 and 0.424 m 3 kg -1 wet wastes or between 0.009 and 0.02 m 3 kg -1 wet wastes per year has been reported (Rees 1985). The produced gases, if not properly managed, could create several adverse effects, such as health risks or global warming con- sequences. The amount of landfill gas generated Environ Monit Assess (2007) 135:41–48 DOI 10.1007/s10661-007-9706-2 C. Chiemchaisri (*) : W. Chiemchaisri Department of Environmental Engineering, Faculty of Engineering, Kasetsart University, 50 Phaholyothin Road, Chatuchak, Bangkok 10900, Thailand e-mail: fengccc@ku.ac.th S. Kumar Solid Waste Management Division, National Environmental Engineering Research Institute (NEERI), Nehru Marg, Nagpur, India J. P. A. Hettiaratchi Department of Civil Engineering, Faculty of Engineering, University of Calgary, 2500 University Drive NW, Calgary, Alberta, Canada T2N 1N4