Solubility of simple aluminium compounds expected in soils. IV. Reactions of aluminium hydroxide under acid conditions

Abstract

Solubility constants for aluminium hydroxides and oxyhydroxides previously obtained (Raupach 1963a) were supported by further studies at 20° and 50°. Polymeric aluminium ions were not present in systems obeying Ks1 = -log [ AlOH2+) (OH-) 2] = 23.31 at 25°C When 5 < -log [AlOH2+] < 3 no Al3+ ions are found in solution because the aluminium hydroxide surface readily binds Al3' ions, produced slowly in solution, and releases AlOH2+ ions. This also happens in soil solutions.