Effects of temperature and particle size on the biochemical methane potential of municipal solid waste components

The effects of temperature and substrate size on the biochemical methane potential (BMP) assay were tested using eight municipal solid waste components. Two sample sizes were tested; size-reduced particles (x < 2 mm) which are typically used for BMP assays and unground samples (x > 20-100 mm) more similar to an as-disposed condition. Two incubation temperatures (35 and 55 °C) were tested for each component. BMPs for office paper, newspaper, paperboard, and coated paper displayed little difference with regards to temperature or particle size. Mesophilic corrugated cardboard BMPs were significantly greater than their thermophilic counterparts. Hardwood, softwood, and cotton BMPs varied with particle size and temperature. Particle size reduction may increase the bioavailable carbon compounds for wood, but this step was not necessary to achieve similar methane yields for paper products. Extrapolating BMP results to predict landfill methane generation may have greater uncertainty for wood wastes and cotton textiles than paper products.