Treatment of refinery wastes using PC/GO/HNTs mixed matrix membranes

• Polymeric composite membranes incorporation of GO/HNTs were synthesized. • The PC-H 4.5 membrane represents the superior performance compared to other one. • PC-H 4.5 demonstrated the highest permeate flux and the most ultrafiltration time. • The performance of PC-H membranes is superior to that of PC-G membranes. • Flux recovery ratio of 96.5% was achieved by PC-H 4.5 in the regeneration cycles. This study pertains to the synthesis of polycarbonate (PC) based mixed matrix membranes (MMMs) utilizing ultrafiltration polycarbonate for the treatment of refinery wastes. An array of analytical techniques, including transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), fourier transform infrared spectroscopy (FTIR), contact angle, and tensile strength tests, was employed. The base membrane was augmented with halloysite nanotubes (HNTs) and graphene oxide nanosheets (GO) at loadings of 1.5%, 3%, and 4.5%. The introduction of HNTs led to increased hydrophilicity and higher pure water flux (PWF), attributed to their amphiphilic nature at higher loadings. Conversely, the incorporation of GO resulted in reduced PWF due to nanosheet agglomeration within the polymeric matrix. Despite these differences, all membranes achieved 100% oil rejection efficiency, albeit with variations in the time required and the permeate flux. The PC-H 4.5 mixed matrix membrane was identified as the optimal membrane, demonstrating the shortest duration to achieve 100% rejection efficiency during ultrafiltration tests at different feed concentrations. Furthermore, a regeneration process utilizing a 30% (v/v) acetone solution was applied to all selected membranes. It is noteworthy that the PC-H 4.5 membrane exhibited 96.5% reusability, indicating its viability for the treatment of refinery wastes.