NEW ASPECTS ON THE CHEMISTRY OF ALUMINUM IN SOILS

Dissolution kinetics of minerals can be significantly inhibited by re- adsorbed aluminum. As a consequence of neutralization, polynuclear Al species may be formed in soil solutions. While re-acidification leads to decomposition of the polymers, further neutralization induces the f ormation of aggregates. The complexation of heavy metal ions with diss olved and aggregated Al polymers is illustrated as a potential factor influencing the chemical speciation of heavy metals in soils.