Abstract:
The purpose of this study was to screen out the best yeast strain capable of COD removal from canned fruit industry wastewater. Using shaking flask cultivation, Candida utilis CBS 1517 was selected among the 5 yeast strains proposed for the comparison. In addition, the optimum pH and N-source for this yeast strain were pH 3.5 and urea at 0.05% (w/v) respectively. The model treatment was then conducted in batch as well as in continuous process using unsterilized wastewater. It was found that in batch culture, the 89.9+-0.11% of COD reduction was obtained in the yeast system as compared to 61.3+-1.15% removal in the control experiment For the model continuous process with 0.23 K/h feeding rate, the yeast system could reduce COD by 66-66.95% as compared to the 22.7-28.6% reduction in the control. Moreover, the COD removal rate of 0-0.34 g COD/L/h was calculated from the batch treatment process while that of continuous was of 0.087-0.392 g COD/L/h.