engleski

Adsorption of toxic metals by iron (III) modified clinoptilolites

The contamination of water resources with toxic metals (copper, zinc, cadmium, lead, chromium, nickel, mercury, etc.) can cause serious problems to human beings, animals and plants. In the recent years, the levels of these toxic metals in surface waters have been increasing due to the pollution caused by industrial wastewaters discharges. Wastewaters from mining operations, electroplating plants, power-generating plants, electronic appliance factories and tanneries contain several toxic metals [1, 2]. Various treatment methods such as ion exchange, ultrafiltration, adsorption, coagulation-precipitation, etc. have been proposed for removal of toxic metals from waters. Among others, one of the most effective method for the removal of toxic metals from waters is their adsorption by low cost adsorbent materials [3-5]. Zeolites, crystalline aluminosilicates with defined structures that consist of a framework formed by tetrahedral of SiO4 and AlO4, have been widely used in toxic metals adsorption experiments. Recently, iron-overexchanged clinoptilolite (Clino-Fe) was tested for removal of Mn2+ ions from drinking water and in Cu2+ ions adsorption from KCl solutions at different pH values [6, 7]. It was reported that Clino-Fe system had much higher adsorption capacity for Mn2+ and Cu2’ ions than unmodified clinoptilolite. In this paper, the natural zeolitic tuff with high content of clinoptilolite was modified with different amounts of iron (III) ions, and the obtained materials were tested for adsorption of copper, zinc, lead and nickel

clinoptilolite ; zinc ; copper ; nickel ; iron modification

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