Incineration generates more heated debate than landfilling. The reputation of incineration as a polluting and unsustainable method is not fair. Incineration is a viable option for communities in the right circumstances. However, it does have environmental consequences.
In the United States, according to the most recent EPA data, 23.6% of municipal solid wastes (MSW) are recycled. Composting was used for another 8.5%, and food waste was managed in other ways for 6.1%. The remaining 61.8% of the waste was disposed of as garbage in landfills or incinerators. In the United States, 72 incinerators are in operation. Only 11.8% of all the garbage in the U.S. is handled by these facilities.
Incineration, like landfilling has evolved over the years. Some supporters of the technology no longer call it incineration, but we’ll get to that later. The environmental impact of a system can be vastly different depending on its age, irrespective of how it is branded. Early incinerators consisted of large, inefficient ovens incinerator manufacturer. The incinerators reduced the amount of waste but still left a large quantity of ash, and partially burned waste at the dump.
In the waste management industry, incineration is often referred to as “waste-to-energy,” or WTE. This term emphasizes the energy recovery process which makes modern incinerators a waste disposal facility and a power generator.
The heat generated by burning waste in most incinerators, and those newly constructed, is used to generate electricity. The electricity generated can be used to offset the costs of construction and maintenance (which are usually much higher than landfilling). According to the EPA, energy recovery ranks higher than disposal in terms of waste management hierarchy. At least for plastics, recycling saves more energy than combustion. Recycling plastic is a challenge. Many communities are forced to consider plastic non-recyclable.
Plastics, being petroleum products, have a high energy content. Incinerators can use them as fuel because they are so valuable. Burning plastics (and waste materials) produces carbon dioxide. This greenhouse gas is as dangerous as the toxic substances that are regulated by the Clean Air Act. In 2016, the US incinerators released 12 million tonnes of carbon dioxide. More than half came from plastics.
Although incinerators constructed after 1990 are undoubtedly cleaner and safer, many people believe that emitting even trace quantities of toxic substances such as dioxins and acids or heavy metals like is not acceptable.Incineration can kill many pathogens, and even some toxic substances. Incineration is preferred for the disposal of biomedical waste and other special wastes in areas where MSW is landfilled.
Incineration has its drawbacks, as many people are quick to point this out. Some combustion by-products are not as useful as electricity. Fly ash is a material that can be used in concrete, but it also contains pollutants and heavy metals.The landfill will never be completely replaced by incineration. Before burning, waste must be presorted. Oversized and hazardous items should go to landfill. After burning, however, there is still waste. Bottom ash is about 15-25% of the MSW that has been burned.