Investigation of the efficiency of water purification from sulphates by means of incomplete freezing
N. L. Lavrik, V. V. Boriskin, K. L. Danilov, V. A. Brednev
Keywords: water purification, freezing - melting procedure, absorption spectra, aqueous solutions of metal sulphates
Pages: 43-50
Abstract
Efficiency of water purification kpur from metal sulphates (MnSO4 в‹… 5H2O, FeSO4 в‹… 7H2O, CuSO4 в‹… 5H2O and VSO4 в‹… 5H2O) is investigated as the dependence on the fraction of frozen aqueous solution (g) and freezing temperature T. The following kinds of dependencies were established: 1) a monotonous decrease in kpur; 2) a monotonous increase in kpur; 3) an increase in kpur with an increase in the fraction of frozen solution to g > 0.3-0.4 followed by a decrease at g > 0.4 (non-monotonous dependence). The influence of reasons preventing high kpur is discussed. These reasons include the impossibility to separate the drops of liquid solution containing impurities from the surface of ice, due to the sampling method (adhesion factor) and freezing of the impurities into the interdendritic cavities on the surface of the freezing front (dendritic factor).
|
