Concentration dependent solute redistribution at the ice/water phase boundary. II. Experimental investigation

Abstract

Solute distribution curves from several hundred ice columns doped with small amounts of HCl, HF, NH4OH, and NH4F were investigated with the log linear approximate solution to the one‐dimensional diffusion equation, discussed in an earlier paper. This led to the discovery of spontaneous convective effects which can be separated from a genuine concentration dependence of the distribution coefficient. The solutes studied show specific characteristics with respect to solubility in ice and concentration dependence of the distribution coefficient. These characteristicproperties should eventually be correlated with specific structural relationships of these solutes (and the defects they create) to the ice lattice. The method of interpretation may be useful for unraveling the freezing history of natural ices of dilute solute content. The most direct and accurate method for measuring the distribution coefficient of (nonvolatile) solutes is by a combination of intense stirring and slow freezing rates.