The dissolution of calcium oxalate in the presence of some natural products

Abstract

The kinetics of dissolution of calcium oxalate crystals has been investigated conductimetrically in several calcium oxalate undersaturated solutions. Over a range of relative undersaturation (0.3-0.8) and at 37ᵒC the process appears into follow a surface controlled dissolution mechanism. The rates of dissolution have been studied as a function pf different parameters such as undersaturation, amount of seeds, hydrodynamics and presence of trace quantities of extracts from medicinal plants. The presence of trace aln0unts of natural products from medicinal plants in the undersaturated solution inhibits the dissolution process. The order of the degree of inhibition is <em>Saccharum > Cymbppogon. </em> Application to a kinetic Langmuir-type model suggests that adsorption of the natural product at the active, dissolution sites is the cause of the reduction in the dissolution rates.