Removal of Arsenic From Aqueous Solution Using Silica Ceramic: Adsorption Kinetics and Equilibrium Studies

The removal of As(III) ions from aqueous solutions has been investigated using silica ceramic under different experimental conditions of initial arsenite concentration, adsorbent dose, temperature and pH. Better removal was obtained at temperature 25ºC and pH 7.5. The adsorption data have been explained in terms of Langmuir and Freundlich equations. The sorption kinetics was tested for the pseudo-first order, pseudo-second order reaction and intra-particle diffusion, at different experimental conditions. The results revealed that the adsorptions of As(III) onto silica ceramic, which werefoundto well, fit bythe Freundlich isotherm. The rate constantsof sorption for kinetic models were calculated and good correlation coefficients (R² > 0.9974) obtained for the pseudo-second order kinetic model. The result indicates that under the optimum conditions, the maximum adsorption value (1.7886 mg/g) comply that the silica ceramic is an effective adsorbent for arsenite.