Ultrafiltration of oil-in-water emulsion using a 0.04-μm silicon carbide membrane: Taguchi experimental design approach

摘要

Oily wastewater as a by-product of the oil industry is becoming a major environmental concern. Finding effective means of treating and recycling the produced water is a key solution for the sustainability of the industry. Filtration experiments were performed to evaluate the performance of a new silicon carbide (SiC) ultrafiltration (UF) membrane in the separation of heavy oil from its brine. The Taguchi experimental design allowed for the investigation and determination of the optimal hydrodynamic conditions including transmembrane pressure (TMP), cross-flow velocity (CFV), temperature, and pH on the permeate flux, and also on the fouling resistance. In addition, the operating parameter with the greatest contribution to the permeate flux behaviour was determined using a statistical analysis of variance. The optimal operating conditions were found to be at 50 degrees C, at a TMP of 0.9 bar, at a CFV of 0.5 m/s, and at a pH of 7. The TMP was found to have the utmost contribution to the permeate flux. Rejection capacity was also examined, and the SiC UF membrane achieved over 96% oil rejection, and one of the highest steady permeate flux levels for a UF membrane among what is published in the literature. Furthermore, models were used to investigate the fouling mechanisms involved in UF treatment of oily water. The cake formation model was found to be the best model for the correlation of the permeate flux decline.