ALUMINUM SOLUBILITY IN RAINWATER AND MOLTEN SNOW

Large variations of aluminium solubilities are found in marine and rur al precipitations. The results of seven field experiments are used to produce a model of the solubilization of aluminium independent of the sampling site. Large variations of solubility appear, and the pH seems to be a major factor explaining this solubility changes. Thermodynami c calculations at T = 278K suggest that, at higher pHs (>5), equilibri um with gibbsite (alphaAl(OH)3) or a trivalent alkaline insoluble form acts as a limiting of aluminium solubility and at lower pH2 (<5), Al could be in equilibrium with a hydroxysulfate salt Al(OH)1.5(SO4)0.75.