Recent advances in cellulose, chitosan, and alginate based biopolymeric composites for adsorption of heavy metals from wastewater

Background: Biopolymer-based materials are getting more attention for sustainable development in various applications, such as energy and environmental remediation. Chitosan, cellulose, and alginate are among the most widely studied biopolymers for water treatment. This review presented the applications of modified biopolymers for decontaminating heavy metals in wastewater. Methods: This review highlighted biopolymers' origin, preparation, alteration, and applications for heavy metal removal in the past decade. The chemically modified or synthesized composites based on chitosan, cellulose, and alginate biopolymers have been discussed in detail. The adsorption behavior of the heavy metals onto modified biopolymeric adsorbents concerning kinetics, isotherms, and regeneration has been presented. The review highlighted potential future research directions that could lead to developing biopolymeric composites more effective for pollutant removal from wastewater. Significant findings: Utilizing biopolymers and their composites as a potential alternative adsorbent to remove pollutants from the industrial effluent minimizes commercial adsorbents' cost and assures environmental sustainability. Many studies report potential applications of biopolymers and their composites to remove heavy metals from wastewater in a single pollutant system. Considering this, more research is necessary to examine the possible applications of biopolymeric composites on binary or multi-pollutant processes.