Investigation of date stone meal efficiency in removal of cadmium from aqueous solutions: Adsorption isotherm and kinetic studies

One of the most important issues of today’s world is water scarcity and water supply pollution with heavy metals. This study aimed to investigate the removal of cadmium ions by date stone meal from aqueous solution.
Date stone meal was prepared of date packaging workshop in Shadegan city, with the permission of the head of the workshop. This was an experimental study in laboratory by batch system. In this study was investigated test variables effects including pH, adsorbent dose, initial concentration of cadmium and reaction time on removal efficiency. The concentration of cadmium ions was measured using atomic absorption. In carrying out this study, and the use of resources, ethical issues was conducted.
The results showed that the adsorption capacity of cadmium on date stone meal dependent on the parameters of pH, adsorbent dose, initial concentration and contact time. Adsorption capacity increased by increasing of pH, adsorbent dose and contact time, while it decreased with increasing initial concentration. The optimum efficiency was obtained in the pH 6, adsorbent dosage of 3 g/L, the initial concentration of 15 mgCd/L, and 15 min contact time. The result showed that cadmium adsorption isotherm by date stone meal is followed the Freundlich model. The best model of cadmium adsorption kinetics in this study, was shown pseudo-second-order kinetic model.
In this study, it was found that date stone meal, have a high ability to adsorb cadmium and can be used as a low-cost adsorbent.