Biosorption sudy of Cr (VI) from the aqueous solution using chemically modified biomass of a newly isolated edible mushroom waste

Abstract

Despite some physiological role in human body, some metals, like hexavalent chromium, have no recognized biological benefit and are poisonous above tolerance limits. For the first time, a widely available Pleurotus sajor caju (fungus) biomass was studied for the Cr (VI) adsorption from an aqueous solution involving physisorption, and chemisorption. Using the batch adsorption method, sorption experiments were conducted, and sorption parameters such as pH, contact time, adsorbent dose, and starting metal ion concentration were studied. The sorbent material was shown to remove up to 91.67% of the Cr (VI) at a pH value of 2. It was discovered that the maximum adsorption (q_max) was 239.98 mg/g. The Freundlich model was adopted for the equilibrium adsorption isotherm for Cr (VI). The biosorption kinetics was ascertained by fitting pseudo-first order and pseudo-second order kinetic models for the experimental data and the pseudo-second order model was found to better describe the data. The interaction of metal ions with the carboxyl, hydroxyl, and carbonyl groups present in biomass is primarily involved in metal ions uptake. This demonstrated the potential application of mushroom residues as a low-cost and promising bio-sorbent.