Fabrication and evaluation of a biopolymer-based nanocomposite membrane for oily wastewater treatment

Abstract

In recent years, discharging a large amount of untreated oily wastewater has become an environmental issue because of the hazardous nature of its oil contents. Membrane separation can be considered an effective method for the treatment of these types of effluents. In this study, polymeric membranes were synthesized to separate oil/water emulsion in Esfahan’s Mobarakeh steel company’s effluent, Iran. The membranes were prepared based on polylactic acid (PLA) physically blended with Polybutylene succinate (PBS), polypropylene carbonate (PPC), and polyhydroxybutyrate (PHB) biopolymers with and without silica nanoparticles (SNPs). Prepared membranes were characterized using methods such as atomic force microscopy (AFM), field emission scanning electron microscopy (FE-SEM), thermogravimetric analysis (TGA), and X-ray diffraction analysis (XRD). An experimental membrane module was also made to evaluate the filtration separation performance of membranes. The results showed that the membranes have suitable properties such as porosity and thermal stability. The membrane containing SNPs showed better separation performance, so that the amount of oil&grease (O&G), manganese, iron, total dissolved solids (TDS), and turbidity in the feed, were removed by 98.6%, 14.17%, 22.56%, 11.33%, and 89.15% respectively, using this membrane.