Patents Assigned to Hampton Roads Sanitation District of the Commonwealth of Virginia
  • Patent number: 4867883
    Abstract: A high-rate biological waste water treatment process for removing organic tter, phosphorus and nitrogen nutrients from municipal waste water comprising the steps of mixing the influent waste water in an initial anaerobic reactor zone to maintain the biological solvents in suspension with a denitrified mixed liquor from a downstream anoxic reactor zone, typically at a flow rate of 0.5 to two times the waste water flow rate. The reactor zone serves to select microorganisms capable of accumulating quantities of phosphorus in excess of that required for simple cell growth and reproduction. The phosphorus removal occurs due to the removal of excess sludge (waste activated sludge) produced in the process wherein such sludge can be removed from the clarifier underflow or as a mixed liquor directly from the biological reactor.
    Type: Grant
    Filed: June 13, 1988
    Date of Patent: September 19, 1989
    Assignee: Hampton Roads Sanitation District of the Commonwealth of Virginia
    Inventors: Glen T. Daigger, James R. Borberg, Liliana M. Morales