title: Freeze-thaw treatment of RBC sludge from a remote mining exploration facility in subarctic Canada.
abstract: Freeze-thaw conditioning of RBC (Rotating Biological Contactor) sludge was tested using a pilot-scale freezing bed placed in a mobile freezer operated at -10°C. Sludge samples from a remote mining exploration facility were flown in every 2 weeks, and added to the freezing bed in 8 layers of 10 cm thick. Approximately 4 months after the first layer of sludge was added, the pilot unit was removed from the freezer and thawed at ambient temperatures. After one day of thawing, the solids concentration increased from 2.6% to 16.2%. The final cake solids concentration was 21%. Melt water had increasing turbidity, COD, TSS, VSS, nitrogen and phosphorus concentrations during the thawing period. Freeze-thaw conditioning also decreased the initial densities of fecal coliforms and Salmonella in sludge. The results of this study showed that freeze-thaw technology successfully dewatered RBC sludge without the need for mechanical equipment, and is a sustainable option for sludge dewatering in cold and remote regions.
authors: Department of Civil and Environmental Engineering, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada.
authors: James
authors: J
authors: Diak
authors: Banu
authors: B
authors: Ormeci
authors: Corinne
authors: C
authors: Proux
mesh_terms: D019149:Bioreactors; D002170:Canada; D005615:Freezing; D008906:Mining; D012722:Sewage; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D012722:Sewage