INFLUENCE OF DISSOLVED ORGANIC-MATTER ON THE KINETICS OF HOMOGENEOUS PRECIPITATION OF ARAGONITE IN SEAWATER

The influence of dissolved organic substances (10(-4) - 10(-6) mole/l) on the induction period time of the homogeneous precipitation of arag onite from seawater has been investigated. Aliphatic polycarboxyl acid s, fatty and aminoacids, phenols, spirits, carbohydrates, some aromati c acids has no influence. Citric and especially gallic acid greatly re tards the precipitation. The effect of natural humic and fulvo acids e xtracted from phytoplankton and marine mud (4 mg C/l) is compairable w ith the influences of 5 x 10(-6) M Gallic acid. The induction period p recipitation of CaCO3 in seawater with natural organic matter does not exceed 200 hours at supersaturation near to 7.