Impact of membrane configuration on the performance and cost of a pilot-scale UF process treating surface water

The performance of ultrafiltration (UF) is heavily influenced by the specifications of membrane modules and operational modes. Pore size, configuration, and material of the UF membrane influence both treatment and filtration performances. The study compares the performance of outside-in and inside-out UF membrane configuration in a pilot-scale system treating surface water. One of the tested UF modules has multi-bore inside-out type membranes (M1), and the other has reinforced hollow fiber outside-in type membranes (M2). Although the treatment performances were quite similar, the filtration performances of the M1 and M2 were different. In long-term pilot-scale operation, the permeability of the M2 module measured 50 L/m².h.bar, while the M1 module measured 34 L/m².h.bar. At the same time, it was observed that the transmembrane pressure (TMP) of M1 was higher than that of M2. A cost analysis was made based on the pilot plant data; estimated capital expenses of 0.019 $/m³ and operation and maintenance (O&M) cost of 0.045 $/m³ were found for the M2 module. This study comparatively presented the long-term operating performance, capital and operational costs for multi-bore inside-out and reinforced outside-in UF membrane configuration.