Hexavalent Ions Sorption on Bentonite Clay

Thumbnail Image
Manasra, Loay
Journal Title
Journal ISSN
Volume Title
Loay Ali Manasra
Radioactive ions, even in low concentration, form a potential threat to the environment and humans due to their strong radiation and long half-life times. The treatment of this serious problem is obviously of great concern and can be investigated by several techniques. The focus of this study is on studying the retention of hexavalent pollutants in bentonite clay. The sorption of hexavalent radioactive pollutants from ground water on Bentonite Clay has been studied using Monte Carlo Simulation. Primitive model has been used where the water is included as solvent with constant dielectric permittivity (εr = 78), and the ions are treated as spheres with same diameter and the Bentonite caly is treated like as electrical double layers. Series of simulations have been performed with systematic variations of different parameters to investigate the sorption of the ions. The parameters including Ionic strength of cations in the aqueous solution, the concentration of ions in the aqueous solution, the surface charge density of the parallel planer surfaces and the temperature of the aqueous solution are checked. The results of this study indicate that: the sorption process is affected by the previous parameters and it can be explained by calculating the retention coefficient of sorption and average electrical double layer concentration. In particular, the average electrical double layer concentration and the surface charge density increase as the concentration of ions increases. By contrast, the average concentration decreases by increasing ionic strength of aqueous solution. In addition, the retention coefficient (γ) of hexavalent ions decreases as hexavalent concentration and ionic strength increasing, and this coefficient (γ) increases by increasing the surface charge density (σ). The results obtained by Monte Carlo simulation method are compared with some available experimental results and found to be in good agreement.
Hexavalent Ions Sorption on Bentonite Clay