Hazardous waste incineration is a waste disposal and control method in which hazardous wastes are burned at high temperatures in order to reduce the hazard they present and to simplify the final process of waste disposal. A hazardous waste is any waste product, such as corrosive chemicals or medical waste, that can pose a significant threat to people or to the environment if proper disposal methods are not used. Incinerating these wastes at a high temperature can, in many cases, actually destroy or otherwise neutralize the harmful components while greatly reducing the final volume of waste. Those who use hazardous waste incineration systems must, however, be careful to avoid releasing pollutants into the air, as many hazardous substances do release gases that could harm people or the environment.
There are three main components to an average hazardous waste incineration system. The main combustion chamber in which extremely high temperatures are maintained is referred to as the rotary kiln. Both solid and liquid wastes are placed in the rotary kiln which rotates slowly to ensure that all parts of the wastes are thoroughly burned. The next part, called the afterburner, is maintained at even higher temperatures and is used to break down the chemical bonds in various gases and atomized liquids. Ideally, these will proceed to react with the oxygen in the chamber to form harmless compounds, such as carbon dioxide and water.
The third primary component of a hazardous waste incineration system is called the air pollution control system, or APCS. Any remaining solid particles or other potentially hazardous materials that remain after the waste passes through the afterburner are reduced to levels specified by a government agency or other regulatory organization. After the hazardous waste incineration process, solid residue remains at the bottom of the rotary kiln. This is collected and analyzed to ensure that it does not contain any hazardous materials. It is further treated to neutralize its potential for harmful contamination as much as possible before it is placed in a hazardous waste landfill.
As with many different disposal methods, hazardous waste incineration can be a risky and sometimes ineffective process. There are many different regulations in place, generally set by a government or by an organization running the incinerator, that ensure that hazardous wastes are handled properly. If, for example, the solid residue is found to contain substances that are still substantially hazardous, the residue will need to be disposed of in a different manner. Failure to follow regulations, particularly those set by a government, may result in serious fines or worse.