Utilization of Ultrafiltration Technology in the Treatment of Sweet Potato Starch Production Wastewater

In order to select a suitable ultrafiltration membrane to treat sweet potato starch wastewater, five different ultrafiltration membranes, including three ceramic membrane (N50, N100 and N200) and two organic membrane (PVDF and PES), were selected to study their effects on three kinds of wastewater from the production process of sweet potato starch. The results showed that all membrane flux decreased significantly in the time of 15 to 25 minutes and then maintained basically stable, of which the ceramic membrane N200 and N50 had relatively high stable membrane flux and the membrane flux of PVDF was higher than that of PES. After ultrafiltration, the light transmittance of wastewater was increased significantly, the remove rates of soluble solids, soluble protein and COD were 39.8%~64.6%, 73.7%~99.0% and 32.3%~73.2%, respectively. The performance of membrane N50, PVDF and PES was better than others. Considering the membrane flux and separation effectiveness, the membrane N50 or PVDF was recommended for further reducing the pressure of subsequent treatment and improving the recovery and of organic compounds in wastewater.