  We study the effect of salts on the thickness of wetting films on melting ice
and interactions acting on CO$_2$ bubble near ice-water and vapor-water
interfaces. Governing mechanisms are the Lifshitz and the double-layer
interactions in the respective three-layer geometries. We demonstrate that the
latter depend on the Casimir--Polder interaction of the salt ions dissolved in
water with the respective ice, vapour and CO$_2$ interfaces, as calculated
using different models for their effective polarizability in water. Significant
variation in the predicted thickness of the equilibrium water film is observed
for different salt ions and when using different models for the ions'
polarizabilities. We find that CO$_2$ bubbles are attracted towards ice-water
interface and repelled from the vapor-water interface
