title: Treatability and kinetics studies of mesophilic aerobic biodegradation of high oil and grease pet food wastewater.
abstract: In this work, batch activated sludge studies were investigated for the treatment of raw pet food wastewater characterized by oil and grease concentrations of 50,000-66,000 mg/L, COD and BOD concentrations of 100,000 and 80,000 mg/L, respectively, as well as effluent from an existing anaerobic digester treating the aforementioned wastewater. A pre-treatment process, dissolved air flotation (DAF) achieved 97-99% reduction in O&G to about 400-800 mg/L, which is still atypically high for AS. The batch studies were conducted using a 4-L bioreactor at room temperature (21 degrees C) under different conditions. The experimental results showed for the DAF pretreated effluent, 92% COD removal efficiency can be achieved by using conventional activated sludge system at a 5 days contact time and applied initial soluble COD to biomass ratio of 1.17 mg COD/mg VSS. Similarly for the digester effluent at average oil and grease concentrations of 13,500 mg/L, activated sludge affected 63.7-76.2% soluble COD removal at 5 days. The results also showed that all kinetic data best conformed to the zero order biodegradation model with a low biomass specific maximum substrate utilization rate of 0.168 mg COD/mg VSS day reflecting the slow biodegradability of the wastewater even after 99% removal of oil and grease.
authors.affiliation: Department of Chemical and Biochemical Engineering, The University of Western Ontario, London, Ont., Canada N6A 5B9.
authors.forename: Victor Lei
authors.initials: VL
authors.lastname: Liu
authors.forename: G
authors.initials: G
authors.lastname: Nakhla
authors.forename: A
authors.initials: A
authors.lastname: Bassi
mesh_terms: D000332:Aerobiosis; D000818:Animals; D000829:Animals, Domestic; D001673:Biodegradation, Environmental; D018533:Biomass; D019149:Bioreactors; D005525:Food-Processing Industry / Q000379:methods*; D007219:Industrial Oils / Q000032:analysis*; D007220:Industrial Waste / Q000517:prevention & control*; D007700:Kinetics; D012722:Sewage / Q000737:chemistry*; D014876:Water Pollution / Q000517:prevention & control*
chemical_list: D007220:Industrial Waste; D012722:Sewage