Removal of Barium From Ground Water Using Clinoptilolite

Adsorption of barium (Ba²⁺_­) on to clinoptilolite, a natural zeolite that has silica and alumina tetrahedral framework was investigated. The adsorption equilibrium and kinetic studies have been performed. The adsorption equilibrium data can be described by the Freundlich isotherm, and the adsorption kinetics of barium follows the pseudo second order reaction model.  The effects of pH, temperature, hardness and ammonia concentration were studied on the barium removal capacity of clinoptilolite. At higher concentrations of barium (100 ppm), hardness had a greater effect and ammonia had less or no effect on the adsorption of barium.  At lower concentrations of barium (10 ppm), hardness had a less effect and ammonia had a more effect on the adsorption. Adsorption of barium onto clinoptilolite was independent of pH of the water. A maximum removal efficiency of 93% was obtained at an initial concentration of 10 ppm. All the experiments were performed at a ground water temperature at 8^oC. ICP-MS was used to measure the concentration of barium in the water. SEM-EDS were used to characterize the adsorbent material.