Efficient removal of radioactive iodide anions from simulated wastewater by HDTMA-geopolymer

摘要

A new adsorbent was developed and investigated for removing radioactive iodide (I-) from wastewater. The HDTMA(12.5%)-geopolymers prepared with the optimum hexadecyltrimethylammonium bromide (HDTMABr)/mekaoline mass ratio of 0.125 were used as adsorbents to remove I- from simulated radioactive wastewater. The HDTMA-geopolymers were prepared by adding HDTMABr into metakaolin-based geopolymeric slurry and characterized using FT-IR, SEM, XRD. The adsorption equilibrium isotherms data of iodide by HDTMA(12.5%)-geopolymer was better fitted with Freundlich isotherm model and the adsorption capability was found as 36.1 mg g(-1). The adsorption kinetics was found to follow the pseudo-second-order kinetics. The thermodynamic analysis revealed that the adsorption process was endothermic and favorable. Limited influence was found on the adsorption process by pH and other large concentrations of competitive anions, such as Cl-, CO32-, SO42- and NO3-. This study demonstrated a new low-cost and efficient adsorbent for removing radioactive I- from wastewater.