Cellulose acetate nanocomposite membranes for efficient textile dye removal

Abstract

Abstract Large-scale dye discharge from the textile industry remains a major environmental concern, with substantial quantities released into wastewater streams each year. In this research, cellulose acetate (CA) nanocomposite membranes incorporating layered double hydroxides (LDHs) and graphene oxide (GO) were fabricated via phase inversion and further systematically investigated for dye removal applications. The structure was characterized by thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and X-ray microtomography (µCT). The results showed that the addition of LDH and GO enhanced the thermal stability of the membrane and made the membrane morphology tunable. Low additive loadings promoted the formation of interconnected porous structures, while higher GO content led to membrane densification and reduced surface area. Furthermore, the nanocomposite membranes' performance strongly depended on nanofiller concentration. The optimal nanocomposite membrane (0.5 wt% LDH, 2 wt% GO) exhibits a removal efficiency of 85% for Congo red and 98% for curcuma owing to the synergistic combination of size exclusion, electrostatic interaction and π–π adsorption. The structure was characterized by TGA, SEM and µCT. The results showed that the addition of LDH and GO enhanced the thermal stability of the membrane and made the membrane morphology tunable. Overall, these results give new insight into the structure-properties and performance in CA nanocomposite membranes and also demonstrate the potential of their use as effective and sustainable materials for wastewater treatment applications.