A substance used to promote water clarity by improving the filtration characteristics of the haze particles. Various terms are use to describe clarification such as flocculate, coagulate and agglomerate. Whatever the term, they work as follows: Turbidity of pool water is sometimes caused by tiny particles which are negatively charged. As each particle has the same charge, they repel each other and cannot coagulate together to allow removal by the filtration system. The addition of a cationic (positively charged) polymer to the water attracts the negatively charged particles to it and allows coagulation.
also called coagulant or flocculant – A chemical compound used to gather (coagulate or agglomerate), or to precipitate suspended particles so they may be removed by vacuuming or filtration. There are two types: inorganic salts of aluminum (alum) or water-soluble organic polyelectrolytes.
Basin where sludge is removed from treated effluent by settling; see Activated sludge treatment