THE KINETICS OF CALCIUM-CARBONATE NUCLEATION IN SEAWATER - THE ROLE OF THE PHOSPHATES AND THE HYDRODYNAMICS OF MEDIUM

The homogeneous nucleation of calcium carbonate was studied both in natural and artificial seawater. The stirring of the solution dramatically decreases the induction period of the CaCO3 precipitation. The phosphate-ion and dissolved organic matter act as strong inhibitors. In natural seawater the logarithm induction period time linearly depends on the logarithm supersaturation: lg tau = 8.2 - 4.58 lgOMEGA. It was shown that the Mg2+ ions can not prevent the inorganic homogeneous precipitation of calcium carbonate from supersaturated surface oceanic waters unlikely the phosphate ion and the dissolved organic matter.