Composting of Municipal Solid Wastes

The generation of municipal solid waste is increasing year by year and there are many options for handling and disposing of these wastes. Currently in United States land disposal is the most common practice to deal with municipal solid wastes. The evolution of waste generation, and increase in population suggest composting as a future alternative. Since municipal solid waste comprises of a high proportion of non-durable goods composting is a suitable technology for reutilizing the organic material. Composting is a natural biological process in which the degradable part of wastes is transformed to a stable material, with excellent characteristics for application on soils. Thus, it requires a pretreatment such as removal of big fractions and other contaminants that could affect the composting process and final quality of the compost. The decomposition of biodegradable material is carried out by very diverse biota, from bacteria to protozoa and worms. This makes composting a successive stage process, where some organisms play varying roles depending on several factors such as temperature, moisture, and nutrient content among others. From an industrial point of view, composting must be optimized by controlling several factors. Although this is a natural process, the control of diverse environmental conditions, waste composition, and waste management lead to a faster process, better quality of the final product and few nuisances such as bad odors. This paper gives an overview of the main aspects of general composting and its application in municipal solid waste treatment.