The COORS BREWING COMPANY of Golden, Colorado operates two wastewater treatment plants to serve both its own facilities and the City of Golden.  Coors treats over 9 MGD of industrial and domestic wastewaters.  The Coors process wastewater treatment plant treats approximately 5 MGD of the total, and produces over 25,000 pounds (dry weight) per day of sludge. Sludge is held in two 80,000 gallon surge tanks for centrifuge dewatering. The holding and processing of sludge Invariably results in the production of strong odors as a result of hydrogen sulfide production in septic sludge. The odor produced in these facilities was unacceptable to Coors Brewing Company and its neighbors.  Phoenix Bio-Systems was part of a Coors project team that developed a biological odor filter to solve the problem.  Air from the holding tanks and the sludge dewatering facility is collected and transferred to the bio-filter for the bio-oxidation of hydrogen sulfide and other volatile odor compounds.  Phoenix provided microbial process design parameters for the design and development of the bio-filter.

     The bio-filter has proven to be very successful in eliminating odor, and has demonstrated very low capital and maintenance costs compared to other means of odor removal.  The system is self-regenerating since it is an "active" or dynamic filter, and has required no backwashing or media replacement since going on stream in 1988.

     Phoenix Bio-Systems has been given permission by Coors to utilize the basic design for its other clients.