Şırnak ash Cd(II) and Zn(II) adsorption to investigate

It is certain that toxic metals have harmful effects on both environment and on biological activities of living organisms as the recent studies shown.Cadmium(Cd) and Zinc(Zn), which are important toxic metals, posses these harmful effects as well.It is well known that our country has significant amount of coal reserves. Every year tonnes of coal are produced, used as an energy source in industry, so coal is an important source of energy. However, evaluation of the residual ash is not so common.The present study was arimed to employ ashes of Şırnak asphaltite coal in for removal of two important toxic metals, Cadmium(Cd) and Zinc(Zn), in high yields by adsorption.Şırnak asphaltite coal was first placed in an ash oven for 4 hours at 900 0C and then it was sreved to -140 mesh. Having seen that solubility of ash in water was too low, several parameters, such as concentration, amount of the adsorbent, pH, temperature and time for Cadmium(Cd) and Zinc(Zn) elements were investigated distinctively.In the adsorption experiments for the unmodified ash, optimum concentrations were found 500 and 400 ppm for Zinc(Zn) and Cadmium(Cd), respectively. Amount of the adsorbent was established as 0,5 and 0,6 g for Cadmium(Cd) and Zinc(Zn), respectively, and beyond these values adsorption decreases as the amount of adsorbent increases.In the pH experiments, higher yield was obtained at acidic region and pH 6 for Cd and pH 5,5 for Zn were determined, which may be attributed to competition of hydrogen and metal ions at strong acidic pH.To investigate temperature effect, several experimens were carried out at four different temperature and it was found that adsorption of Cadmium(Cd) and Zinc(Zn), increased as temperature increased. Reactions were determined as endothermic and 60 0C was chosen as optimum temperature for both metals.In determining equilibrium contact time, nature of the adsorbent as well as reaching of the yield a maximum when the adsorbent adsorbed the metal ion are important factors. In these studies the equilibrium contact time for Cd was 40 hours, where as that for Zn was 2 hours.In the kinetic studies, four different temperatures were investigated, the data were applied Lagergren and Ho-McKay equations and the results were fitted best for Ho-McKay equation. After these kinetic studies, adsorptions isotherm were studied and adsorption isotherms were plotted for four different temperatures, which were fitted Giles? L type isotherm. Adsorption isotherm of Cadmium(Cd) and Zinc(Zn) were fitted best Langmuir isotherm.In the second part of the study, ?G ?S and ?H values were found by calculating the thermodynamic parameters.In conclusion, it was determined that the ash could be employed as unmodified from and ıts adsorbance features were studied for Cadmium(Cd) and Zinc(Zn) toxic metals.