Nano-Chitosan coated sand: A sustainable superadsorbent for removal of heavy metals and dye particles from industrial effluents

Abstract

Nano-chitosan-coated sand adsorbent was prepared by coating chitosan nanoparticles onto treated Padma River sand. CNPs were produced through the application of ionotropic gelation methodology. The effects of parameters such as pHs, adsorbent dosages, contact times, initial dye concentrations, and temperatures were examined on the maximum adsorption capacity. The maximum adsorption capacities of brilliant green, methylene blue, reactive brown dyes, chromium, and nickel heavy metal ions by NCCS were observed at a temperature of 318 K, which were 5.001 mg/g, 8.012 mg/g, 6.386 mg/g, 48.387 mg/g, and 24.258 mg/g, respectively. The adsorption process conformed to the Langmuir adsorption isotherm, indicating that the adsorption was monolayer. The adsorption process was spontaneous and endothermic across the temperature ranges. As the reaction kinetics analysis indicated, the adsorption process followed a pseudo-second-order kinetic model. The adsorption capacity of NCCS is exceptionally high, allowing for the effective capture and removal of a diverse array of heavy metals and dyes from aqueous solutions, consequently contributing to the advancement of environmental remediation and pollution abatement initiatives.