Exfoliate apricot kernels, natural low-cost bio-sorbent for rapid and efficient adsorption of CN- ions from aqueous solutions. Isotherm, kinetic and thermodynamic models

Abstract

ABSTRACT Exfoliate apricot kernels were collected and prepared for adsorbing the cyanide ions from the aqueous solution. Fourier transforms infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) and scanning electron microscopic (SEM) were utilized to describe the exfoliate apricot kernels. The adsorption experiments carried out were in a batch experiment, prepared 100 mL of cyanide solution for various temperature, pH, contact time, speed of mixer and dose of the adsorbent. The isotherms models were checked Langmuir, Freundlich, Temkin, and Harkins-Henderson, isotherm models. The isotherm coefficient of Langmuir, Freundlich, Temkin, and Harkins-Henderson models were 0.99, 0.8, 0.95 and 0.68 respectively. The Langmuir isotherm model best fitted for adsorption more than other models. The kinetic were studies pseudo-first-order, pseudo-second-order, intra particle diffusion, and Elovich kinetic models. The kinetic(R2) constant for pseudo-first-order, pseudo-second-order, intra particle diffusion, and Elovich were 0.989, 0.947, 0.969 and 0.904 respectively. Pseudo-first-order giving a better fit for the process.