Particle size analysis of municipal solid waste for treatment process modeling

Several unit operations used in municipal solid waste (MSW) processing facilities are based on physical properties of the waste materials, such as particle size, density and shape. Reliable expressions describing particle size distribution (PSD) of the different waste components present in MSW are not readily available in the context of process modeling. In this study, the characterization data for household wastes and construction and demolition (C&D) wastes were analysed with the purpose of selecting the most representative PSD expression for these waste streams. The Rosin-Rammler distribution was identified over the log-normal and the gamma distributions as the best-fitting PSD for the waste samples. This was demonstrated for both raw and processed waste samples. Parameters were derived and validated for every category of MSW materials considered in the characterization. A model for mixed household waste PSD was developed based on the summation of Rosin-Rammler expressions corresponding to each category of waste materials, as the composition was determined to be the main factor influencing particle size. A simplified model was also derived for mixed waste as a bimodal distribution since two main modes were observed in household waste - one for the "organic" fraction and one for the "inorganic" fraction.