Latex-Based Membrane for Oily Wastewater Filtration: Study on the Sulfur Concentration Effect

Abstract

Nitrile butadiene rubber (NBR) latex/graphene oxide (GO) membranes were fabricated through a latex compounding and curing method which is a relatively new method to produce membranes for wastewater treatment. Hence, the steps in the production of the membrane through this new approach need to be evaluated to optimize the performance of the membrane. In this paper, the effect of sulfur loading in the range of 0.5 to 1.5 parts per hundred rubber (phr) on the morphology, crosslink density, tensile properties, permeation flux and oil rejection rate performance of NBR/GO membranes was studied. The sulfur loading was found to influence the surface morphology and integrity of the membrane which in turn affects the performance of the membrane in terms of strength, water flux and rejection rate of oil. Inaccurate sulfur loading produced a membrane with micro cracks, low surface area for filtration and could not withstand the filtration pressure. In this research work, the membrane with 1.0 phr sulfur provides the highest water flux value and oil rejection rate of 834.1 L/m2·hr and 92.23%, respectively. Surface morphology of 1.0 phr sulfur-loaded membrane revealed the formation of continuous membrane with high structural integrity and with wrinkles and folded structure. Furthermore, micro cracks and a less effective surface area for filtration were observed for membranes with 0.5 and 1.5 phr sulfur loading.