Treatment and Management of Hazardous Solid Waste Stream by Incineration

Hazardous waste is generated from many sources, ranging from industrial, manufacturing processes, agricultural practices, etc., and may come in many forms, including liquids, solids, gases, and sludges. The waste incineration technique is one of the waste-to-energy technologies that can reduce waste effectively and generate energy. However, the technology will generate high amounts of toxic gases such as dioxin and nitrous oxide, requiring high energy and operational cost as well. The residues that are generated from the incineration are incineration bottom ash or fly ash, which can also be known as hazardous waste because it contains a high number of pollutants that will affect the environment and human health. Various studies have found a way to treat the incineration fly ash before discharging it to the landfill. Since the incineration fly ash contains a high concentration of heavy metals, stabilization and solidification of the heavy metals is needed to prevent the leaching of heavy metals. Most of the incineration fly ash can be used as a replacement material in construction materials to enhance mechanical properties and reduce the leaching of heavy metals. Although incineration fly ash can be applied to construction materials, an optimum mixing ratio is required because a high replacement ratio will reduce the mechanical properties of the materials. Co-incineration is advised to lessen the burden of incineration in order to combat the high disposal of municipal solid waste by incineration. However, co-incineration is not suitable for long service; alternative techniques are needed to overcome the high disposal of waste. The laws and regulations for incineration need to be enforced to protect the environment and humans.