Waste treatment refers to the activities required to ensure that waste has the least practicable impact on the environment. In many countries various forms of waste treatment are required by law.
The treatment of solid wastes is a key component of waste management. Different forms of solid waste treatment are graded in the waste hierarchy.
Agricultural wastewater treatment is treatment and disposal of liquid animal waste, pesticide residues etc. from agriculture.
Industrial wastewater treatment is the treatment of wet wastes from manufacturing industry and commerce including mining, quarrying and heavy industries
Sewage treatment is the treatment and disposal of human waste. Sewage is produced by all human communities and is often left to compost naturally or is treated using processes that separate solid materials by settlement and then convert soluble contaminants into biological sludge and into gases such as carbon dioxide or methane.
Radioactive waste treatment is the treatment and containment of radioactive waste.