Effect of Filtration Time on the Performance of PVDF Membrane for Palm Oil Mill Effluent Treatment

Palm oil mill effluent (POME) is a high-viscosity wastewater generated during palm oil processing. Its high content of oil and grease, suspended solids, and colloidal organic matter contribute to elevated turbidity and pollutant loads. Therefore, effective treatment is necessary before POME can be discharged into the environment. Membrane filtration is a potential treatment method for reducing turbidity by retaining suspended and colloidal particles. This study investigated the effect of filtration time on the performance of a polyvinylidene fluoride (PVDF) hollow-fiber ultrafiltration membrane for POME treatment, with particular emphasis on pure water flux, permeate flux, and permeate turbidity. Before filtration, POME was pretreated with alum at a concentration of 1 g/L. The feed characteristics were assessed by measuring turbidity. Filtration was performed using a dead-end system at a constant pressure of 1 bar for 60 minutes, with measurements taken at 15-min intervals. Pure water flux was measured before POME filtration to establish a baseline for evaluating membrane performance. The results showed that pure water flux decreased from 345.5 to 247.4 L/m²·h, while permeate flux decreased from 56.6 to 10.7 L/m²·h over the filtration period. Meanwhile, pretreatment reduced feed turbidity from 5,060 to 405 NTU, corresponding to a 92% reduction. Subsequent membrane filtration produced permeate turbidity as low as 1.06 NTU at 30 minutes, representing a 99.74% reduction relative to the pretreated feed. The decline in flux indicated increased resistance to permeation, potentially due to the accumulation of retained materials on the membrane surface.