Characteristics and Impacts of Municipal Solid Waste (MSW)

The term “Solid Waste” based on the Resource Conservation and Recovery Act (RCRA), means any garbage or refuse, sludge from water and wastewater treatment plants, or air pollution control facilities, and other discarded material, resulting from industrial, commercial, mining, and agricultural operations, and from community activities. It is important to note that the definition of solid waste is not limited to the physical solid state. Many solid wastes are liquid, semi-solid, or contain gaseous material. Municipal Solid Waste (MSW) more commonly known as trash or garbage, originally included any discards in urban areas, may contain product packaging, grass clippings, furniture, clothing, bottles, food scraps, newspapers, appliances, and batteries. The comprehensive waste management system generally encompasses four stages: (1) waste generation, (2) collection and transport, (3) physical/biological/thermal treatment, and (4) landfilling. Considering all environmental, economic, social, and political aspects, one could evaluate and select the best option to handle any of the four above-mentioned stages in a comprehensive waste management system. Furthermore, identifying the physical, chemical, and biological characteristics of the waste stream is essential in the selection process. The first step in determining the characteristics of MSW is to identify the main sources of MSW in the study area. Resources can be classified based on generation tonnage, location, and existing laws and regulations. Subsequently, the tonnage of waste in resources should be estimated. MSW generation per capita depends on various factors such as the level of public welfare, type of economic activities, population distribution, climate, culture, and customs. The main physical/chemical/biological properties of MSW include density, material composition, particle size distribution, moisture content, and heating value. Identifying waste characteristics would be especially useful to design and to operate recycling or energy recovery facilities. Preparation of samples with appropriate size (to estimate optimal accuracy), separation of components, and necessary analysis are essential to determine waste characteristics.