We are always on the lookout for applications of ozone in water treatment. One area that is gaining a lot of attention is water recycling. Ozone is an excellent choice for water recycling since it is short lived breaking down to oxygen after use. It can also be produced on site from air eliminating the need to purchase, store or transport chemicals. Finally, ozone can play many roles in water treatment, sometimes simultaneously, like disinfection or color/odor removal. Color removal was the main application in the application below.
New England Patriots Gillette Stadium uses a wastewater recycling system to conserve water for the town Foxborough, MA. The treatment system employs biological, chemical and physical processes for removal of contaminants. The plant computer controlled.
The biological portion of the plant employs membrane bio reactors (MBR). The permeate stream from these reactors is pumped to Ozone and Ultraviolet units. Ozone is injected into the wastewater stream to eliminate residual color and UV is used to disinfect the wastewater.
The water is then directed to the final effluent tank. This fully treated water is either pumped to a remote storage tank for reuse or to the designated leach field for disposal. Approximately 80 percent of treated water is pumped back to the facilities and 20 percent goes to subsurface disposal. This saves an estimated 12 million gallons of water per year.