Alginate-based magnetic adsorbents for the adsorption of organic and inorganic pollutants

The pollution of water driven by organic and inorganic contaminants is a serious environmental problem demanding pioneering and eco-friendly remediation measures. Alginate is a naturally sourced biopolymer that has received significant attention owing to its biocompatibility, biodegradability, non-toxic nature, and high affinity for removing pollutants. While these adsorbents offer several advantages, their limited mechanical integrity and complex separation procedures have hindered widespread practical use. The promising strategy to address these shortcomings involves magnetic functionalization, which enhances structural robustness, enables material recovery and reuse, and facilitates fast separation from aqueous media through external magnetic fields. This review explores the development of magnetically functionalized alginate adsorbents, detailing their synthesis methods, structural characteristics, and adsorption behaviour toward organic and inorganic contaminants. The section on key factors influencing adsorption performance, such as solution pH, temperature, dosage of adsorbent, initial pollutant concentration, and availability of competing ions, is thoroughly discussed. The regeneration and recyclability of materials are also proposed to assess their long-term practicality. Despite promising lab results, challenges lie in scaling up production, maintaining activity against multispecies wastewater matrices, and structural resilience under changing conditions. Future investigation should focus on synthesis protocols, enhancing recyclability, and evaluating environmental implications, with a particular focus on minimizing the carbon footprint associated with adsorbent fabrication. Furthermore, the application of artificial intelligence (AI) for designing magnetic adsorbents opens up new possibilities for modulating material properties, boosting performance, and advancing cleaner and more sustainable water treatment methods. This review aims to provide informative insights into the progress and challenges related to alginate-based magnetic adsorbents and their important role in the eco-friendly removal of organic and inorganic pollutants from aquatic environments.