(1) Any water or wastewater treatment process that precedes primary treatment; may include aeration, equalization, pH adjustment, grit removal, grease removal, screening, skimming, comminution or other processes. (2) The treatment of industrial wastewater at its source before discharge to municipal collection systems.
Changing the properties of a liquid-solid mixture by physical or chemical means to improve its filterability. Chemical means include coagulation, flocculation and conditioning. Physical means include size classification, preaeration, mechanical agitation, freezing and thawing, heating, ultrasonic and mechanical vibrations, electronic and magnetic treatment and ionising radiation. Filter aids are also used for pre-treatment.
techniques to reduce/minimize pollutants prior to treatment facilities. In storm water, typically associated with detention basin forebays designed to capture or trap coarse sediments to preserve storage and prevent clogging. In wastewater, usually associated with industrial/commercial sites intended to reduce their discharge pollutant concentrations to levels that can be accommodated by a municipal wastewater treatment facility.
a treatment used to break seed dormancy before planting.
Methods used by industry and other non-household sources of wastewater to remove, reduce, or alter the pollutants in wastewater before discharge to a POTW.
treatment of wastes prior to entering the sewer system.
The reduction of the amount of pollutants, the elimination of pollutants, or the alteration of the nature of pollutant properties in wastewater prior to, or in lieu of, discharging or otherwise introducing such pollutants into a POTW.
Specialized industrial wastewater treatment, performed at the source, that makes the wastewater suitable for discharge to a public sewage system.
Processes used to reduce, eliminate, or alter the nature of wastewater pollutants from non-domestic sources before they are discharged into publicly owned treatment works (POTWs).
Processes used to reduce the amount of pollution in water before it enters the sewers or treatment plant.
The treatment of industrial wastewater to remove contaminants prior to discharge into municipal sewage systems.
The chemical treatment of unpainted metal surfaces before painting, for enhanced adhesion and corrosion resistance.
Onsite process to remove hazardous constituents from industrial wastewaters prior to their release to the sanitary sewer system.
Any water treatment step performed prior to the primary treatment process, such as filtration prior to deionization.
