Rapid adsorption of As(V) from aqueous solution by ZnO embedded in mesoporous aluminosilicate nanocomposite adsorbent: Parameter optimization, kinetic, and isotherms studies

Abstract

In this work, ZnO modified mesoporous AlSBA-15 nanocomposite adsorbent was prepared by wet chemical method and employed to adsorption of As(V) from an aqueous solution. The adsorbent was characterized by XRD, SEM (EDS), N2 sorption, and FTIR spectroscopy. The surface area, pore-volume, and pore diameter was estimated to be 373 m2 /g, 1.01 cc/g, 7.31 nm respectively. Arsenic (V) adsorption studies were conducted in the batch model. In optimized condition, the maximum adsorption capacity found to be 123.994 mg /g at pH 4.5, adsorbent dose 4g/L, and temperature 298 K. Rapid adsorption occurs within the first 30 min with adsorption efficiency of 99.13%. The results obtained from the kinetic model showed that the adsorption process followed pseudo-second-order kinetics well with an R2 value of 0.9999. Adsorption isotherm investigation showed the Langmuir model fitted well the experimental data with an R2 value of 0.996. Moreover, the adsorption process occurs through electrostatic attraction between the adsorbent and As(V) ions. Adsorption efficiency decreases with the increase of temperature and hence exothermic.