Solid waste includes solid portion of material such as glass bottles, crockeries, plastic containers, metals and radioactive wastes, etc.
Liquid waste includes effluents of industries, fertiliser and pesticide solutions from agricultural fields, etc.
Gaseous waste is mostly generated by human activity. The gaseous wastes include carbon dioxide (CO2), methane (CH4), chlorofluorocarbon (CFC), oxides of nitrogen (NOx), carbon monoxide (CO) etc.