Development of alginate graphene oxide hydrogel as a sustainable platform for emulsion separation

Oil–water emulsions released from industrial activities, ship discharges and offshore operations pose a serious environmental challenge due to their persistence, toxicity, and difficulty of removal. These emulsions can infiltrate aquatic systems, degrade water quality, threaten marine biodiversity, and disrupt ecological balance, underscoring the urgent need for efficient and sustainable separation technologies. This study explores the development and application of graphene oxide (GO) fused with an alginate biopolymer to form a hydrogel membrane for efficiently treating oil-water emulsions. The hydrogel membrane, synthesised through a facile in-situ polymerisation method, incorporates graphene oxide for enhanced mechanical strength, adsorption capacity, and selective permeability. The incorporation of GO into the alginate matrix significantly enhanced tensile strength by 1.4 times compared to the pristine alginate membrane. Wettability analysis revealed a significant reduction in the water contact angle to 1 °, indicating enhanced super-hydrophilicity that facilitated improved water permeability. The pure water flux improved by 1.2 times for the optimised membrane. Continuous flow experiments demonstrated the membrane’s high emulsion separation capacity and reusability over multiple cycles, with a flux recovery ratio of 91.8% after five cycles. The results suggest that the GO-fused alginate hydrogel membrane system offers a promising solution for emulsion separation, with performance characteristics that highlight its potential as a sustainable, scalable material for treating oily wastewater and addressing broader environmental pollution challenges.