Usage of natural zeolite in removal of heavy metals from wastewater: Ion exchange capacity for zinc, lead and cadmium with clinoptilolite

One of the important environmental problems is the pollution caused by the heavy metals in wastewater. In the present work, it is investigated the possibilities of removing the heavy metals that lead, zinc and cadmium in wastewater by an ion exchange method using clinoptilolite which is a natural zeolite.In the first part of the study the chemical analysis of the original clinoptilolite has been carried out and X-ray diffraction patterns. Following this step, clinoptilolite has been converted into homo ionic form by using sodium ion. As a result of this procedure, it has been observed that the clinoptilolite in sodium form is saturated with sodium by 80 % to raw clinoptilolite.In the second part of the study the clinoptilolite samples converted into sodium form is treated with 0,1 N concentration of Pb(NO3)2, Cd(NO3)24H2O, Zn(NO3)26H2O solution, where the g-zeolite to solution ratio was 1/100. Using the results of chemical analysis of sodium, calcium, magnesium, potassium, lead, cadmium zinc and measurements in the scope of the experiments has been determined the exchange ratio of sodium ions within clinoptilolite with lead, zinc, cadmium cations. Our study tried to identify the real ion exchange capacity in sodium formed clinoptilolites.As a result of chemical analysis that the clinoptilolite in sodium form has been determined 1,6 meq g-sodium / g?clinoptilolite for theoretical ion exchange capacity. As a result of our tests it has been identified that real capacity for lead, 0,97-1,288 meq g-sodium / g?clinoptilolite, real capacity for cadmium, 0,83-1,2332 meq g-sodium / g?clinoptilolite, real capacity for zinc 0,785-1,224 meq g-sodium / g?clinoptilolite.