ABSTRACT
Process purpose: Water treatment sludges Surface water inžuent streams include solids, which must be removed and then somehow disposed. Two principal types of sludge result from water treatment: coagulation sludge and softening sludge. After large solids are separated from the raw water by screening, suspended solids and particulate matter remain in the inžuent until it is removed by coagulation and žocculation. More solids wastes are formed with water softening treatment. Other sludge sources in water treatment include grit from presedimentation, solids from ›lter backwash, from iron and magnesium removal, and from slow sand and diatomaceous earth ›ltration.
