The present disambiguation page holds the title of a primary topic, and an article needs to be written about it. It is believed to qualify as a broad-concept article. It may be written directly at this page, or drafted elsewhere then moved over here. Related titles should be described in Sludge, while unrelated titles should be moved to Sludge (disambiguation).
Sludge is a semi-solid slurry and can be produced as sewage sludge from wastewater treatment processes or as a settled suspension obtained from conventional drinking water treatment and numerous other industrial processes. The term is also sometimes used as a generic term for solids separated from suspension in a liquid; this 'soupy' material usually contains significant quantities of 'interstitial' water (between the solid particles).
Industrial wastewater treatment plants produce solids that are also referred to as sludge, whether generated from biological or physical-chemical processes.