| Abstract: | This study investigated the potential of ultrafiltration technology and/or biological treatment to remove contaminants such as total dissolved solids (TDS), chemical oxygen demand (COD), total organic carbon (TOC), and resin and fatty acids (RFAs) from recirculated white water. Batch ultrafiltration experiments indicated that TDS, soluble COD, and TOC removal efficiencies were affected by membrane molecular weight (molar mass) cut-off, but were independent of the operating temperature, in the 20 to 60°C range. Except for fatty acids, where average removals exceeded 90%, the separation efficiency of the process for all other parameters (TDS, soluble COD, TOC, and resin acids) was moderate, ranging from 10 to 41%. Biological treatment using a sequencing batch reactor (SBR) unit was very effective in removing RFAs, TOC, total and soluble COD. Furthermore, ultrafiltration of the biologically treated process water resulted in significant additional TDS, soluble COD, and TOC removal. |
