Department of Food Science, Stellenbosch University, Private Bag X1, Matieland, South Africa
Robertson, L., Department of Food Science, Stellenbosch University, Private Bag X1, Matieland, South Africa; Britz, T.J., Department of Food Science, Stellenbosch University, Private Bag X1, Matieland, South Africa; Sigge, G.O., Department of Food Science, Stellenbosch University, Private Bag X1, Matieland, South Africa
Two 2 L laboratory-scale upflow anaerobic sludge blanket (UASB) reactors were operated for 277 days. The substrate of the control reactor (R<inf>c</inf>) contained grain distillery wastewater (GDWW) that had undergone coagulant pre-treatment, and the substrate of the second UASB reactor consisted of GDWW that had undergone coagulant pre-treatment and ozone pre-treatment (R<inf>o</inf>). Both reactors treated pre-treated GDWW successfully at ca. 9 kgCOD m-3 d-1. Chemical oxygen demand (COD) reductions of ca. 96% for R<inf>c</inf> and 93% for Ro were achieved. Fats, oils and grease (FOG) reductions (%) showed variations throughout the study, and reductions of ca. 88 and 92% were achieved for R<inf>c</inf> and R<inf>o</inf>, respectively. R<inf>c</inf> produced more biogas, and the methane percentage was similar in both reactors. UASB granule washout in R<inf>c</inf> suggested possible toxicity of unsaturated fatty acids present in non-ozonated substrate. The feasibility of FOG removal was demonstrated as both reactors successfully treated pre-treated GDWW. Better results were obtained for R<inf>o</inf> effluent during post-ozonation. The ozone pre-treatment possibly led to easier degradable wastewater, and better results could potentially be obtained when other post-treatment steps are applied. Ozone pre-treatment did not, however, show an added benefit in the reactor performance results. © IWA Publishing 2014.
Anaerobic digestion; Chemical oxygen demand; Coagulation; Effluents; Methane; Oils and fats; Ozone; Ozone water treatment; Ozonization; Unsaturated fatty acids; Coagulant; Control reactors; Distillery wastewaters; Fats , oils and grease; Pre-Treatment; Reactor performance; Up-flow anaerobic sludge blanket reactors; Upflow anaerobic sludge blankets; Wastewater treatment; bicarbonate; biogas; coagulating agent; methane; ozone; unsaturated fatty acid; volatile fatty acid; ozone; sewage; anoxic conditions; chemical oxygen demand; coagulation; fatty acid; granular medium; ozone; performance assessment; sludge; substrate; wastewater; water treatment; alkalinity; anaerobic digestion; Article; biodegradability; biomass; carbon source; cell division; chemical oxygen demand; degradation; distillation; grain; methanogen; ozonation; pH; reduction; upflow reactor; waste water; anaerobic growth; bioreactor; cereal; chemistry; distillation; procedures; sewage; Anaerobiosis; Bioreactors; Cereals; Distillation; Ozone; Sewage; Waste Disposal, Fluid