Zeitschrift für Chemieingenieurwesen und Prozesstechnologie
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Abstrakt

Effect of Immobilization of Cadmium Ions on the Hydration of Ordinary Portland Cement

Minocha AK and Manish Kumar Goyal

The disposal of toxic wastes containing heavy metals may cause a peculiar environmental problem especially when these metals are present in water soluble form. In the present research varying concentration of cadmium ions have been studied for their effect on physical, chemical and engineering properties of 43 grade Ordinary Portland Cement like initial and final setting time, compressive strength, bulk density, leaching studies, microscopic studies etc. our Efforts have been made to establish a quantitative corelation between the different concentrations of cadmium ions used and the intensity of any change in above properties of the cement. Nitrate salt of cadmium has been taken in the concentration range 1000-5000 ppm and the results of these investigations are presented in this paper.
The results show that Cd improves the Compressive strength as well as the bulk density of the mortar samples. The leaching studies shows that the concentration of cadmium is almost negligible in the leachate analysed by the Atomic Absorption Spectrophotometer and as the concentration increases in the mortar samples the leaching of cadmium ions decreased it shows all the added cadmium ions gets adsorbed on the surface of cement. Scanning electron microscopic studies shows that the C-S-H gel phases are denser than that of control samples and C-S-H phases are responsible for the improved compressive strength of cement samples.