| Abstract: | The recovery and concentration of proteins from the waste water of a fish plant was achieved by ultrafiltration. Two UF modules equipped with Ceraver and Patterson Candy International (PCI) membranes were tested. Despite different cut-off values, similar apparent rejection coefficients (70% and 80% respectively) were obtained. Optimum economic conditions were established, corresponding to average transmembrane pressures of 2·2 × 105 and 3·8 × 105 Pa and tangential flow rates of 6·0 and 0·47 m s−1 for Ceraver and PCI membranes, respectively. The protein concentration in the feed solution was increased from 5 to 35 g dm−3. The study showed that the method could reduce pollution due to organic matter by decreasing the value of the Biological Oxygen Demand after 5 days (BOD5) by about 80%. |
