Metal Ion Exchange by Natural Zeolites

The influence of pretreatment on the capacity and selectivity of natural zeolite for Zn2+ and Mn2+ ions has been studied. Natural tuff (sample 1), consisting mainly of zeolite clinoptilolite, was converted into the Na+ form by conditioning with 2 M NaCl at 22 °C (sample 2) and 70 °C (sample 3), respectively. Simultaneously, 0.26, 0.31, 0.38 mmol Zn2+ and 0.20, 0.23, 0.30 mmol Mn2+ were taken up by 1.00 g of zeolite samples 1, 2 and 3, respectively. The results show that zeolites converted to the Na+ form at 70 °C possess the highest capacity for metal ions. For all the zeolite samples tested, zinc was more selectively removed than manganese. The amount and composition of exchangeable cations as well as their impact on ion-exchange performances of zeolite in the process of Zn2+ and Mn2+ removal were determined

CONTRIBUTION TO THE KNOWLEDGE OF BIOELEMENTS IN VEGETATION AND SOIL BY ATOMIC ABSORPTION SPECTROPHOTOMETRY

U ovom članku opisan je osnovni princip primijenjene atomske apsorpcione spektromaterije ("AAS") kod određivanja bioelemenata (metala) u biljnom materijalu i tlu. Iznijete su prednosti i nedostaci u „AAS“ u ursporedbi s ostalim analitičkim metodama pri određivanju tragova metala. Grafički i tabelarno prikazani su rezultati analize tla i biljnog materijala lista kukuruza uzgojenog na tlu različitih pretkultura. Prikazani rezultati u tabeli broj 4 i 5 odnose se na makroelemente Ca i Mg, te na mikroelemente Mn, Cu, Fe i Zn.In this article the fundamental principle of the applied atomic absorption spectrometry (AAS) for the determination of bioelements (metals) in vegetation and soil is treated. Advantages and imperfections in „AAS“ compared to other analytical methods for the determination of metal traces are given. Graphs and tables with the results of soil analysis as well as of the corn leaf analysis, the corn being raised on the soil where various plants were raised before, are presented. The results given in tables 4 and 5 refer to macroelement Ca and Mg and to microelements Mn, Cu, Fe and. Zn