Reverse osmosis of edible vegetable oil industry effluent

Pilot-scale reverse osmosis (RO) studies were carried out to determine the feasibility of the process for treating the wastewater from a vegetable oil industry. The effect of varying feed pressure (0–69 bar) and feed TDS concentration (0.54–5.2% w/v) on separation performance of the thin film composite (TFC) polyamide RO membrane was determined. At original effluent composition and feed pressure of 55.2 bar, high rejection of TDS (99.4%) and COD (98.2%) along with complete rejection of color and BOD was achieved with a reasonably high flux of 52.5 l/(m2 h). The flux and percent rejection of pollutants improved significantly with increasing transmembrane pressure at constant feed concentration but decreased with increasing feed TDS concentration. RO was found to be very suitable for treating oil effluents having TDS concentrations upto 52215 ppm.