engleski

Aditive influence on calcium carbonate precipitation in artificial karst water

Tufa is a natural calcium carbonate porous material, with the mineralogical composition of mostly calcite or magnesium calcite. Tufa is formed by deposition of calcium carbonate in fresh water streams, in the area of intensive water splashing (waterfalls) [1]. With the degradation of plant material present in water and on the riverside, organic molecules are released. Humic and fulvic acids resulting from decomposition are known to inhibit the growth and deposition of calcium carbonate [2]. Also, in the water, pollutants in the form of phosphates and various polyphosphates are present because of human influence and play a significant role in inhibiting CaCO3 growth [3]. The aim of this research was to create a simple physicochemical model of the tufa sedimentation that will enable a better insight into sediment deposition processes and to determine the influence of additives (humic and fulvic acid, phosphate and polyphosphate) on polymorphic composition and morphology in artificial karst water, at different temperature. Obtained samples were characterized by means of FTIR/ATR spectroscopy and SEM microscopy. The results indicated that the additives have a major influence on the polymorph composition as well as on the crystal morphology. The additive influence is as follows: humic acid < fulvic acid < phosphate < polyphospate.

calcium carbonate ; humic acid ; fulvic acid ; tufa

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