All of the organic acids studied were effective inhibitors of calcite growth at relatively low concentrations (< 5 mg/l) compared to concentrations observed in Everglades surface waters (25 to 50 mg/l). Thus, although calcite supersaturation is observed in Everglades waters, kinetic inhibition by natural organic acids probably prevents abiotic precipitation from occurring.
Below, we have plotted chemical characteristics of the organic acids versus reduced rate in the presence of 1.0 mg/l inhibitor. Rate reduction correlates most strongly with molecular weight and aromaticity. Work is in progress to determine more precisely what properties of the organic acids are most responsible for crystal growth inhibition.
