Research Associate Professor, University of Waterloo, Waterloo, Ontario
Pages: 22 Published: Jan 1997
The Waterloo Biofilter™ is a new type of free-draining aerobic biofilter developed at the University of Waterloo to treat domestic septic tank effluent, but it is also effective for municipal sewage, landfill leachate, and other wastewaters. The optimized physical properties of the light-weight, plastic foam medium enable design loading rates of 50 cm/d, or ∼10 times that of soil leach fields and sand filters. The medium combines high retention time with high surface area for microbial attachment and allows simultaneous loading and aeration. Separate flow paths for air and water allow concurrent aerobic and anaerobic reactions, and minimal solids production. Maintenance is similar to a sand filter but more readily cleaned if needed. Typical mature field removal rates in a single pass are: Municipal Primary Clarifier:>95% BOD and TSS, >99.5% for total and fecal coliforms, and ∼80% ammonium at 50 cm/d; Municipal Secondary Clarifier or Lagoon: >90% BOD and TSS, >95% ammonium at 250 cm/d; Proteus METS System: 80–85% BOD and 75% TSS at 500 cm/d; Septic Tank Effluent: 90–95% BOD/TSS, 95–99% for coliforms, and 50–95% ammonium at 50 cm/d; andLandfill Leachate: 80–95% BOD, 95% ammonium, 98% hydrocarbons and VOCs and 50–95% heavy metals at 30 cm/d. Typical total nitrogen removal is 20–50% for sewage and depends on degree of nitrification. Preliminary virus work indicates efficient removal.
onsite wastewater treatment, soluble BOD, Waterloo Biofilter, septic systems, municipal sewage, nitrification, landfill leachate
Paper ID: STP13803S