Incineration

Incinerators are an alternative option to the disposal of general municipal garbage in solid-waste disposal sites. Municipal incinerators accept organic wastes and combust them under controlled conditions. The major benefit of using incinerators for this purpose is the large reductions that are achieved in the mass and volume of wastes.

In addition, municipal incinerators can be engineered as waste-to-energy facilities, which couple incineration with the generation of electricity. For example, a medium-sized waste-to-energy facility can typically take 550 tons (500 tonnes) per day of municipal solid wastes, and use the heat produced during combustion to generate about 16 megawatts of electricity. About 2-3 megawatts would be used to operate the facility, including its energy demanding air-pollution control systems, and the rest could be sold to recover some of the costs of waste disposal.

Among the major drawbacks of incinerators is the fact that these facilities have their own problems with NIMBY, mostly associated with the fears of people about exposures to air pollutants. As is discussed in the next section, incinerators emit a wide range of potentially toxic chemicals to the environment.

In addition, municipal incinerators produce large quantities of residual materials, which contain many toxic chemicals, especially metals. The wastes of incineration include bottom ash that remains after the organic matter in the waste stream has been combusted, as well as finer fly ash that is removed from the waste gases of the incineration process by pollution control devices. These toxic materials must be disposed in sanitary landfills, but the overall amounts are much smaller than that of the unburned garbage.

Incinerators are also opposed by many people because they detract from concerted efforts to reduce the amounts of municipal wastes by more intensive reducing, recycling, and reusing of waste materials. Incinerators require large quantities of organic garbage as fuel, especially if they are waste-to-energy facilities that are contracted to deliver certain quantities of electricity. As a result of the large fuel demands by these facilities, it can be difficult to implement other mechanisms of refuse management. Efforts to reduce the amounts of waste produced, to recycle, or to compost organic debris can suffer if minimal loads of fuels must be delivered to a large incinerator to keep it operating efficiently. These problems are best met by ensuring that incinerators are used within the context of an integrated scheme of solid waste management, which would include vigorous efforts to reduce wastes, reuse, recycle, and compost, with incineration as a balanced component of the larger system.