Biopolymer-driven nano technology for industrial effluent remediation; the emerging role of alginate- based nano-composites; A review

The contamination of water resources with heavy metal ions (HMs) presents a significant challenge that necessitates the use of highly effective remediation techniques, including enhanced adsorption. Alginate-based hydrogels, in particular, have garnered considerable attention as a promising class of advanced adsorbents. This interest stems from their numerous oxygen-rich functional groups, ease of chemical alteration, wide availability, and environmentally friendly and sustainable nature. This overview synthesizes recent developments in the removal of HMs using alginate-based hydrogel sorbents. Nano-based composites of alginates have become a focus for their application as biosorbents in addressing environmental concerns, such as the extraction and reclamation of heavy metals from contaminated water sources, owing to their unique properties. The primary characteristics that support the application of alginate-based biosorbents for environmental remediation include: high selectivity and sorption capacity, renewability, and the ability for safe handling. Additionally, their sorption capacity can be improved through straightforward physical and chemical modifications, and they are easily separated from treated water, facilitating simple regeneration and reuse over multiple sorption-desorption cycles. This review further delves into the mechanisms that govern the adsorption process. Finally, it outlines the existing challenges and future directions for the creation and application of these materials. It is anticipated that this compilation of pertinent information will encourage further scientific investigation into advancing functional alginate-based hydrogels for adsorption purposes