شهریار عصفوری

Usage of low cost adsorbents is one of the most promising methods used to reduce ions. In this research, performance of natural zeolite clinoptilolite, activated carbon and activated alumina have been investigated. This adsorbents was modified by NaCl,HCl and Nacl and HCl in a row to increase their performance. Effective variables on the ion-exchange process, such as contact time and amount of adsorbent consumption were examined experimentally. Results showed that the optimal aging time and consumption of adsorbents concentration for zeolite, activated carbon, and activated alumina are 90 minutes and 40,60,60 gr/L drinking water respectively. Consumption of adsorbents concentration for zeolite, activated carbon, and activated alumina are 60,40,40 gr/L undergrand water respectively. Also, maximum reduction percent of drinking water hardness parameters, in optimal condition, were observed at (93.07%) for Zeolite, for Activated Carbon (19.42%) and for Activated Alumina (56.92%). Maximum reduction percent of undergrand water hardness parameters, in optimal condition, were observed at (59.23%) for Zeolite, for Activated Carbon (15.67%) and for Activated Alumina (39.72%). According to results obtained from experiments, it can be concluded that the NaCl modified Zeolite, Natural zeolite, and NaCl-HCl modified Activated carbon has better performance in reduction of parameters respectively. Also, under optimized conditions Activated carbon has the best efficiency in reducing total dissolved solids. In order to study the kinetic of calcium and magnesium ions adsorption process by three adsorbents, three different models consisting pseudo first order and second order kinetics models and Mauritius-Weber model were implemented. Among these models, second order kinetics model showed the highest match with experimental data. Furthermore, three isotherm models including Langmuir, Freundlich and Tamkin were used to study the equilibrium of adsorption process which Langmuir model pre