Equilibrium and Kinetic Analysis on Cadmium Ion Sequestration from Aqueous Environment by Impregnated Chicken Feather Alkaline Biosorbent

Abstract
The presence of cadmium ions in the environment is dangerous to a human being because of its chronic and acute health syndromes such as hypertension, testicular atrophy, and skeletal fetus malformation. To eliminate cadmium ions from the environment, cheap, non-toxic, and environmental-friendly biosorbents, an alkaline impregnated adsorbent, were prepared in this study. Alkaline impregnated chicken feather biosorbents (AICFB) were synthesized and characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) analysis. The AICFB prepared was employed for the cadmium sequestration from simulated wastewater. AICFB quantity, cadmium ion concentration, and temperature are parameters with significant effects on the metal ion sequestration process. Models by Langmuir, Freundlich, and Redlich-Peterson were assigned to analyse the adsorption isotherms. Experimental data seem good with all tested models, and best with the Redlich-Peterson model. The maximum sorption capacity of AICFB toward cadmium ion was 122.07 mg/g as monolayer entrapment at pH 6.5, 0.1 g of AICFB, 120 minutes contact time, and 298 K. The linear pseudo-first-order and pseudo-second-order kinetic models were applied for the analysis of kinetic data. The pseudo-second-order model suitably describes the cadmium ion uptake by AICFB, indicating the chemisorption process. The prepared AICFB demonstrates efficient cadmium metal sequestration from aqueous environments.