Copper Removal Using Different Fungal-Based Adsorbents: A Comparative and Detailed Study

Abstract

Chitosan purified from Mucor indicus biomass as well as the biomass and its derivatives including cell wall and the residues remaining after chitosan extraction were evaluated for copper removal from aqueous solutions. Chitosan was extracted using hydrochloric and acetic acids. The acid type did not affect the adsorption capacities of the chitosans and the corresponding cell wall residues, while the rate of biosorption by the adsorbents produced using acetic acid was higher than those produced using hydrochloric acid. Pseudo-second-order model described the kinetics data appropriately. The highest level of the maximum adsorption capacities predicted by Langmuir model was found for the cell wall (84 mg/g) and the chitosans (81 mg/g), whereas the lowest level was observed for the cell wall residues (about 3 mg/g). Scanning electron microscopy micrographs showed modification of the absorbents surfaces, resulting in different adsorption behaviors. FTIR analysis identified the involvement of different functional groups for copper removal.