Patent ID: 7622036

Claim:
A bio-tank oxygen replenishment system, comprising: a cyclonic two stage mixer for mixing wastewater with gaseous oxygen, wherein the mixer includes a head including an oxygenated head space, an outer housing having a wastewater inlet in fluid communication with a plenum defined by a space between the outer housing and an inner cartridge, the inner cartridge having a plurality of ports which are selectively opened and closed to permit wastewater flow therethrough and into a down tube; a sensor for measuring the size of the head space; a bioreactor tank for processing the wastewater mixed with oxygen; a probe for measuring oxygen concentration of the wastewater in the bioreactor tank; a controller responsive to the probe measurements, wherein the controller regulates mixer pressure thereby regulating the oxygen concentration of the wastewater in the bioreactor tank; and a circulation pump for transferring wastewater from the bioreactor tank to the mixer, wherein the controller sets the circulation pump speed to optimize the wastewater oxygen concentration.