Computational Insights into the Adsorption of Toxic Contaminants on Eco-Friendly Chitosan Composites

Chitosan-based adsorbents have gained popularity in water treatment because they are biodegradable, inexpensive, non-toxic, and rich in amino and hydroxyl groups. However, their practical application is limited by issues like weak mechanical strength, low thermal stability and limited selectivity. These challenges can be overcome by physically or chemically modifying chitosan or by effectively combining it with other materials to form composites and hybrid materials. Computational techniques such as density functional theory (DFT) and molecular dynamics (MD) simulations have been widely studied. These techniques allow modelling at the molecular level, which helps in successfully predicting the properties of the prepared materials and understanding the mechanism of pollutant adsorption. This review analyses the recent developments of computational techniques in studying the adsorption of dyes, heavy metal ions, pharmaceutical compounds and toxic anions on chitosan-based materials. Through this analysis, the application of DFT and MD simulations in understanding the interaction of the pollutants with the active sites on the chitosan surface and the effect of various experimental conditions on the adsorption process has been discussed in detail.