Effect of Organic and Inorganic Impurities
on the Nucleation of Calcium Oxalate Monohydrate
O. A. GOLOVANOVA1, YU. O. PUNIN2, A. S. VYSOTSKIY1 and V. R. KHANNANOV1
1 Omsk State University,
Pr. Mira 55A, Omsk 644077 (Russia)
golovanoa2000@mail.ru
2 St. Petersburg State University,
Universitetskaya Naberezhnaya 7/9, Saint Petersburg 199034 (Russia)
Keywords: calcium oxalate monohydrate, induction period, amino acids, inhibition, crystallization
Pages: 463–470
Abstract
On the basis of the experimental data, a set of problems connected with the features of the crystallization of wavellite in the presence of additives is considered. It is established with the help of X-ray phase analysis that the precipitates formed under the conditions studied are presented by calcium oxalate monohydrate. The presence of magnesium ions, hydrophosphate, phosphate and sulphate ions in solution has an inhibiting action on the crystallization of calcium oxalate monohydrate. The hindering effect of the additive increases proportionally to an increase in the concentration of the additive. It was proved experimentally that amino acids have diverse effects on nucleation: some of them (glutamic acid, glycine, lysine etc.) inhibit the process, whereas the others (proline, alanine, valine etc.) act as catalysts; a number of amino acids (serine, phenylalanine) exhibit an insignificant effect on nucleation.
UDC 577.118.543.422
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