Application of microfiltration and ceramic membranes for treatment of salted aqueous effluents from fish processing

The results of microfiltration (MF) studies using ceramic 150 kDa membrane and model solutions containing bovine serum albumin (BSA) with and without NaCl as well as salted wastewater from fish industry are reported. The aim of the research was experimental analysis of operating parameters enabling regeneration of waste brine for recycling purposes. In the first step of the research effect of pH, NaCl concentrations, and pressure difference across the membrane on BSA rejection and permeate flux was experimentally investigated. The transmembrane pressure was changed in the range of 0.05–0.2 MPa. MF tests were performed at temperature 20°C and cross-flow velocity of 4 m/s using feed consisted of BSA (1.0 g/dm3) and NaCl (10 wt.%). In the second step of the research industrial brine from fish processing was characterized and pretreated by bag filters 100 and 1 µm. The MF tests with brine were performed in concentration mode, without permeate recycling to feed tank. The high protein rejection (81%) and significant rejection of BOD and COD, 72 and 60%, respectively, was observed.