Isotherms, Kinetics and Thermodynamic Studies for Removal the Valium from Stomach and Intestine Fluids via Adsorption on Egg Shells Powder.

Drug abuse or overdose in accidents is a serious social issue. This study concerned the adsorption behaviour of the Valium drug in both simulated gastric and intestinal pH onto the untreated eggshell powder by using UV spectroscopy. The effects of various experimental parameters such as contact time, pH-solution, an adsorbent dosage of Valium and temperature range (300-320k) on the adsorption capacities have been investigated. The suitability of Langmuir and Freundlich adsorption models to the experimental equilibrium data at different solution temperatures were calculated. The adsorption was well described by the Freundlich isotherm model and Langmuir, S₃ for the stomach and S₂ for the intestine according to the Giles classification. Thermodynamic parameters such as ∆H°, ∆G°, and ∆S° results showed that the adsorption of the drug increases by increasing the temperature in the stomach solution, i.e., the endothermic reaction decreases by increasing the temperature at the intestinal solution, i.e., the reaction is exothermic. Experimental data were also tested in terms of adsorption kinetics, the results illustrated that the adsorption process was following pseudo-second-order kinetics in the stomach solution and first order in the intestinal solution. [ABSTRACT FROM AUTHOR]