Original paper

Evaluation of the Speciation of Inorganic Constituents in Sediments of the Reservoir at Altenwörth of the River Danube

Sager, M.; Pucsko, R.; Belocky, R.


Samples from the reservoir of the River Danube at Altenwörth/Lower Austria, three grain sizes and unsieved, were submitted to two independent sequential leaching methods. In the leaches, the elements Al, As, Ca, Co, Cr, Cu, Fe, K, Mg, Mn, Ni, P, Pb, and Zn have been determined by AAS-, ICP- and photometric methods. The leaching patterns obtained are compared with literature data gained by similar procedures. Correlation and factor analyses are used to find the composition of possible phases in the solid, and their significance for heavy metal uptake. In many cases, trace element behaviour is dominated by an Fe/Al/Mn-surface correlated phase, whereas Zn and Pb are quite mobile in dilute acid, and Cu is the only tightly bound to humics as well. In general, heavy metals in the investigated samples are more mobile upon acidification than upon reduction, contrary to P and As. K, Al, Fe, and Cr are mainly refractory. Ammonia contents of the pore water affects the mobile fractions, except the Fe-dominated phases. Grain size is the most decisive parameter, whereas sampling site within the reservoir, and season are not significant.