A Bio-Reactor is a biological wastewater treatment system used to degrade high levels of BOD. This is achieved with the use of a series of tanks, blowers, and pumps that specially designed to maintain an aerobic biomass (population of bacteria that eat the organic constituents that makeup the BOD). A Bio-Reactor gives industry an option to treat BOD in an economical and reliable manner

The Bio-Reactor can decrease BOD 80-98% and has an estimated area footprint of 36-45 square feet per 1,000 gallons of water treated per day.  It basically runs itself.  Maintenance is 20 min/day; the pH controller needs calibrating, the return sludge needs to be monitored, and the solids coming off the screen need to be managed.  Operational costs depend on the size of the system.  Costs include electricity, chemicals and labor which averages $0.002 US per gallon treated or $0.04 US per pound of BOD reduced.

A Bio-Reactor starts by screening out all of the larger particulates.  The wastewater is flow equalized and pH adjusted to 7-8 in an equalization chamber.  Aeration starts in the following chamber where blowers supply air as well as mixing energy to the wastewater.  The BOD levels are reduced as the bacteria "eat" the BOD.  A clarifier follows the aeration chamber where the solids settle to the bottom, and get returned to seed" the incoming wastewater with healthy bacteria.  The clarified effluent then flows out of the Bio-Reactor.  Depending on the site requirements, the treated water can be used for irrigation, land applied, water-reuse, or discharged to the Publicly owned Treatment Works (POTW)