What is sludge?

Sludge is a semi-solid, residual material that is generated during the treatment of wastewater or industrial wastewater. It typically consists of a mixture of organic and inorganic solids, along with water and some dissolved materials.

Sludge is generated during the primary and secondary treatment stages of wastewater treatment. Primary treatment involves the removal of large particles and debris from wastewater, while secondary treatment involves the use of biological processes to remove dissolved and suspended organic matter.