Physical, chemical and bromatological characterization of the organic fraction of urban solid waste: Potential and possible applications

Characterizing the generation of urban solid waste is essential for suitable decision-making regarding an urban solid waste management strategy. This study aims to characterize the urban waste generated in Toluca, Mexico, and to compare the results obtained in samples taken from households with primary separation against wastes from a municipal deposit. The wastes were gathered from 52 nuclear single-family homes for the experimental work, and the solid samples were collected during three months. Results showed that fruit waste from households predominated (52%) compared to the waste from the municipal deposit (32%). Vegetables and legumes, gardening, and processed food wastes were similar in percentages for both samples analyzed. Household waste showed a volatile solids/total solid ratio of 0.95 ± 0.04, whereas municipal deposit waste was 0.80 ± 0.07. In terms of physical and chemical composition, household waste presented significant differences in parameters such as alkalinity, chemical oxygen demand, nitrates, and fixed solids compared to waste from municipal deposits. In bromatological terms, no statistical difference was observed (3763-3808 kcal/kg) either in nutritional value or in the balanced composition of carbohydrates, proteins, lipids, and fiber. Heavy metals (As, Cd, Cr, Pb, Ni, Cu, Zn, and Hg) in both wastes met standard regulations. Finally, the solid wastes might be used for compost, biofuels, biogas, bioethanol, incineration with energy recovery, and animal feed.