The Effect of Ozonation Pre-treatment in Enhancing the Biodegradability of Effluent from Distillery of Ethanol Fermented from Molasses

Abstract — The effect of ozonation on the biodegradability of distillery wastewater in a batch anaerobic digester was investigated in semi-batch pilot-scale experiments. The organic matter and color reductions as well as gas production were monitored. The total COD and color reduction during the 30 minute ozonation were 24 11 % and 51 7 %, respectively. Further anaerobic treatment resulted in average total COD reduction of 57 7 % compared to 38 14 % for wastewater similarly treated by batch anaerobic digester and without prior ozonation. Without ozonation pre-treatment, there was no color removal in the anaerobically treated wastewater. While with ozonation pre-treatment 44 12 % color removal was achieved. Gas production for wastewater with and without ozonation pre-treatment was 27 L and 28 L, respectively. The biogas production in the anaerobic digester was more stable when the influent is pretreated with ozonation than without prior ozonation pre-treatment