Optimization of Co2+ ions removal from water solutions via polymer enhanced ultrafiltration with application of PVA and sulfonated PVA as complexing agents

► In this study, we examined UF-complexation process for the removal of Co2+ ions from water solutions. ► Two different water-soluble polymers were used, non-modified PVA and modified PVA by sulfonation. ► The method of experimental design and response surface methodology have been employed. ► Co2+ removal ability of sulfonated PVA was much higher than its non-sulfonated precursor.