Porous polyvinyl butyral membranes incorporating copper oxide nanoparticles as efficient adsorbents for oil removal

This work focuses on designing porous membranes prepared according to the non-solvent induced phase separation technique using polyvinyl butyral (PVB) as polymer matrix, incorporating CuO nanoparticles as filler at 2, 5, and 7 wt%. The PVB/CuO membranes were characterised before testing their adsorption performances concerning sunflower seed oil (SSO)/water emulsion and correlating them to the CuO loading. Different parameters such as contact time (0–24 h), pH (2−12), temperature (20–80°C), adsorbent dosage (1–5 g/L) and salinity (0–100.000 ppm) have been investigated. The SSO removal process is favoured at pH= 7 and 80°C for the PVB/CuO (2 %) samples. The 2 % CuO-loaded PVB membrane showed the highest adsorption performances (up to about 1400 % for SSO) and great adsorption performances for other oils (silicon oil, pump oil, waste and diathermic oil). PVB/CuO membranes were successfully regenerated, and their capacity remained about constant for up to 5 cycles.