Tertiary Wastewater Treatment
The purpose of tertiary treatment is to provide a final polishing treatment stage prior to discharge or reuse of the wastewater.
Chlorination – A water treatment method that destroys harmful bacteria, parasites, and other organisms. Chlorination also
removes soluble iron, manganese, and hydrogen sulfide from the water.
Ozonation – A water treatment process that destroys harmful bacteria and other microorganisms through an infusion of ozone.
Ozone (O
3) is a gas created when oxygen molecules are subject to high electrical voltages.
Ultraviolet radiation – A disinfection process for water and wastewater treatment that involves passing
Ultraviolet (UV) light through water. UV light destroys microorganisms and can reduce dissolved organic material.
Activated carbon absorption– A physical process that is typically applied as tertiary treatment to remove low concentrations of
contaminants from water that are difficult to remove by other means. Activated carbon has been processed to make it extremely porous, thereby creating a
very large surface area available for adsorption of contaminants. Activated carbon may have a surface area as great as 1500 m
2/g (7.3 million ft
2/lb).
Ion exchange – Ion exchange is a reversible chemical reaction used to remove ions from water and wastewater. An
ion in solution, such as ammonium, copper, calcium, magnesium, and many others, is exchanged for a similarly charged ion attached to an immobile
solid ion exchange particle. These solid ion exchange particles are either naturally occurring inorganic zeolites or synthetically produced organic resins.
