Biosorption of Chromium by Agricultural Waste, Anacardium Occidentale Testa Powder: Characterization, Kinetic, Isotherm and Thermodynamic Studies

Abstract The study on low-cost biosorbent such as Anacardium occidentale testapowder was used to remove chromium from aqueous solutions. Based on R 2 values, the Langmuir (R 2 = 0.9927) model fitted the equilibrium biosorption data best, confirming monolayer adsorption of chromium on to the biosorbent surface. The biosorption of chromium was best described by pseudo-second order (R 2 =0.9902) kinetics since at all concentrations, the R 2 values were higher than the corresponding pseudo-first order (R 2 = 0.9278) values. Based on thermodynamic parameters the biosorption of chromium by Anacardium occidentale testa powder was found to be spontaneous, endothermic and feasible under optimized conditions.