Surface modification of silica gel for adsorptive removal of Ni2+and Cd2+from water

Abstract

AbstractIn this study, surface of silica gel was functionalized with 1,2-ethylenediamine. The synthesized materials were characterized by Fourier transform infrared spectroscopy, scanning electron microscope, and elemental analysis. Batch adsorption studies were carried out to analyze the adsorption of nickel and cadmium ions from aqueous solutions. The factors influencing % adsorptive removal of Ni2+ and Cd2+ onto the silica gel and functionalized silica gel, such as initial pH value of the Ni2+ and Cd2+ ion solutions, adsorbent dose, initial Ni2+ and Cd2+ ion concentration, contact time, and temperature were investigated. Langmuir and Freundlich isotherm models were used to determine the isotherm parameters associated with the adsorption process. The monolayer adsorption capacity of ASG for Ni2+ and Cd2+ increased from 4.69 to 19.6 and 7.63 to 27 mg/g, respectively, after modification of activated silica gel (ASG) surface with 1,2-ethylenediamine. Kinetic data were analyzed considering pseudo-first-orde...