Cellulose-based materials for scavenging toxic and precious metals from water and wastewater: A review

The abundance of cellulose in nature, as well as its biocompatibility and functional groups, has paved the way for the development of advanced cellulose-based technologies for water and wastewater treatment. This comprehensive review provides a detailed overview of recent advances in cellulose-based adsorbents, focusing on surface functionalization and potential applications in water and wastewater treatment technologies. The investigation of numerous cellulose-based adsorbents has demonstrated that the introduction of surface functional groups such as carboxyl, succinate, amine, imidazole, amidoxime, thiol, thioether, sulfonate, dithiocarbamate, xanthate, phosphate, and so on through chemical modification techniques significantly improves their adsorption properties and selectivity towards metallic species. The review delves into the use of cellulose-based adsorbents for the removal of potentially toxic elements, radionuclides, and the recovery of precious metals from water and wastewater. Furthermore, the potential of blended adsorbents that incorporate various types of cellulose in the form of composites, nanocomposites, and hybrids is highlighted. Furthermore, this review assesses cellulosic biomaterials with varying cellulose contents to determine their potential as metal sorbents. Finally, current research trends, gaps, challenges, and future perspectives in this field are brought to the forefront.