Biosorption of Cd (II) from Solution using Cashew (Anacardium occidentale) Leaf: Kinetics, Equilibrium, and Thermodynamics

The presence of metal ions in aqueous solutions represents a major environmental problem. These inorganic species are persistent and non-biodegradable pollutants that should be eliminated from water. It occurs due to the direct and indirect discharge of diverse chemicals into the water bodies without sufficient treatment to reduce and diminish the harmful compounds. The biomass materials utilized in this research were cashew (Anacardium occidentale) leaves. This was discussed along with the principal factors affecting the biosorption process, such as solution pH, biomass dose, metal ion concentration, and contact time. The potential health and environmental hazards of metal ions, in addition to the kinetic and isothermal models assessed to fit the biosorption experimental data, were also considered. The kinetic and isothermal models follow pseudo second order and Freundlich, respectively. The maximum biosorption was obtained at 180 minutes at pH 5 and 323 K for an initial Cd (II) concentration of 90 mg/L. This indicates that the cashew (Anacardium occidentale) leaf is a good biosorbent for the treatment of Cd (II)-bearing wastewater. Keywords: Biosorption, Biomass dosage, pollutant, wastewater