engleski

Structural investigation of metal sorption on naturale zeolite

This study show the investigation of possibilities for application of natural zeolite from Croatia in process of metal ions removal (zinc, chromium, arsenic) as well as their complex compounds industry wastewaters( zinc, chromium) and drink water( arsenic). Natural zeolite show affinity towards the metal ions and they found wide range of application for metal ions removal from water solution what is shown in several publications (Cerjan-Stefanović et al., 1996: Metal Ion Exchange by Natural Zeolites, Croat. Chem. Acta, 69 (1) 281). Detail characterization of natural zeolite includes roentgen diffraction structural analysis, differential thermal analysis, measurements of specific area and density. Metal species are determined by UV/VIS and AAS. The influence of natural zeolite treatment (granulometric and chemical treatment, time of equilibrium, concentration and pH value of metal ions solution, type and concentration of ligand) on capacity and selectivity of ions removal has been investigated. It is proved that mentioned parameters have great influence on ion exchange processes of zeolite and metal ions (Rožić & Cerjan-Stefanović, 2002 Evaluation of Croatian Clinoptilolite and Montmorillonite-rich Tuffs for Ammonium Removal, Croat. Chem. Acta, 75, 255.) Naturale zeolites in contact with zinc, chromium and arsenic ions is a complex problem, because of the appearance of zinc, chromium and arsenic in several ionic shapes towards which zeolite has different affinity. Up to 95 % effectiveness of arsenic removal from drinking water is achieved by use of sorption materials and their modified forms in arsenic removal technologies. In recent years, research is being conducted in the world on new materials, natural and synthetic zeolites, and the possibilities of their use in technologies of arsenic removal in the final stage of drinking water treatment process.. The possibility of using natural zeolite, as a sorption agent in the final stage of drinking water treatment process was tested.The concentration of residual arsenic, which after primary treatment is approx. 30 - 35 μ g/l, was brought to lower that maximum allowed concentration of 10 μ g/l.Such a model of final treatment of water with high arsenic concentration can be used combined with various technologies of primary arsenic removal.

industrial and drink water; zinc; chromium; arsenic; modified natural zeolite

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