| Abstract: | The effect of montmorillonite and kaolinite, most common clay in marine water, on nucleation and growth of calcium carbonate in standard sea water was studied. Crystallization was induced by the degasification of the dissolved carbonic gas. It was shown by XRD and SEM analysis that CaCO3 crystallize under its aragonite polymorph some either the clay concentration or type. It was also found that tested clays inhibited significantly the crystallization of calcium carbonate, especially for concentrations higher than 25 mgL–1. From the fine analyses of the formed solid, it was suggested that the tested clays have an indirect effect on nucleation and growth of aragonite by increasing the Mg ions concentration, strong inhibitor of CaCO3 formation, in the neighbourhood of clay particles where supersaturation is the higher and than crystallization can occur. In addition to its indirect role, kaolinite can interact with aragonite by adsorbing on their faces and blocking growth sites (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) |
