Recent progress in adsorptive removal of different contaminants by chitosan-based aerogel

Rapid industrial development has led to the discharge of significant amounts of untreated industrial wastewater into the environment, resulting in substantial effects on natural ecosystems and human health. Consequently, there is a need to develop new environmentally friendly alternatives for water remediation. In this regard, chitosan (CS) aerogels possess high porosity, low density, and biodegradability, and act as effective sorbents for the removal of various ionic pollutants from water, air, and soil. The presence of numerous amino (-NH₂) and hydroxyl (OH) groups enhances the adsorption of ionic pollutants via electrostatic interactions, hydrogen bonding, and chelation mechanisms. This review provides an overview of the use of chitosan-based aerogels as eco-friendly gels to remove different contaminants from water such as dyes, heavy metals, microorganisms, and pharmaceuticals, by improving the mechanical strength, decreasing hydrophilicity, and increasing acid stability. These improvements are accomplished using different modification methods, such as blending with nanofillers, chemical and/or ionic crosslinkers, and designing composite aerogels. The modified aerogel exhibits excellent adsorption ability against different contaminants, as well as antibacterial properties, making it promising candidates for a wide range of applications.