Recent advances in polymer nanocomposites for the adsorptive removal of toxic azo dyes from water

Abstract Adequate wastewater treatment technologies are essential for addressing toxic dyes’ environmental pollution and health hazards. Azo dyes which contain one or more azo bonds are widely used in the textile. However, they are known to be carcinogenic, mutagenic, and highly toxic to human health. Traditional wastewater treatments methods, such as coagulation, flocculation, and biological treatment, often fail to eliminate dye molecules due to their complex structures and strong chemical stability. Therefore, there is a need for advanced solutions. Polymer nanocomposites have emerged as a promising alternative, offering high surface area, tunable properties, and exceptional adsorption capacities. This review describes recent reports on the synthesis, characterization, and application of polymer nanocomposites for azo dye removal, incorporating key findings such as the remarkable adsorption capacity of gelatin nanocomposite (950.5 mg/g). However, most studies were used synthetic dye solutions with limited validation in real industrial effluents. This paper also describes future research development with scalability, cost analysis, and biodegradability for practical use. This review aims to guide future research toward more effective adsorbent, eco-friendly, and scalable wastewater treatment for dye removal.