Freisetzung von Aluminium durch Eintrag von sauren Niederschlägen und Charakterisierung der mobilen Aluminium Spezies

According to the results of experiments in hydroponic cultures, Al-toxicity for plants is caused by free Al 3+-ions. Since the existing analysis schemes are not applicable to distinguish between the free Al3+-ions and the labile Al-complexes a method of isotachophoresis was developed, allowing the determination of environmentally relevant concentrations of free Al3+-ions. By means of the 8-hydroxychinolinmethod monomeric inorganic Al-compounds were determined. In addition to these compounds the catecholviolet method was applicable to detect kinetically labile Al-organo-complexes. Using a cation exchange resin a differentiation between exchangeable and non-exchangeable Al-complexes was possible. On the basis of combined application of these methods a new speciation scheme of Al-compounds in the mobile soil phase was developed. The feasibility of the analysis scheme was checked by means of lysimeter experiments. The effects of acid irrigation and liming on formation and mobilization of A l-species and nutrients in soil could be elucidated.