ZnO/Cassava Starch‐Based Hydrogel Composite for Effective Treatment of Dye‐Contaminated Wastewater

Industrial expansion has increased the discharge of contaminated wastewater. Wastewater can be treated by adsorption with petroleum-based hydrogels but materials are not biodegradable and therefore cause secondary toxic waste. In this work, hydrogel composites prepared based on non-biodegradable polyacrylamide cassava starch (CS) poly(vinyl alcohol). The effect CS content porous structure is studied. highest water absorption capacity 74 g g−1 obtained from a 30 wt% CS. Within 4 h, effectively adsorbs cationic dyes methylene blue (MB) crystal violet, anionic congo red reactive orange. maximum toward MB 993 mg g−1. Experimental data indicate monolayer via chemisorption. Silica-coated ZnO photocatalyst particles synthesized sol–gel method coated outer surface hydrogel. Under sunlight, composite degrades almost 90% adsorbed dye. capable effective photodegradation for at least three cycles under artificial UV irradiation four remains higher than 80% eighth cycle. also shows antibacterial activities, indicating an additional beneficial property industrial wastewater treatment.