The reactivity of primary Pb metallurgical slags in high-molecular-weight (HMW) organic solutions has been studied in order to determine the processes of release and attenuation of metal and metalloid contaminants (Pb, Zn, Cu, As) in 'soil-like' environments. Slag was submitted to a 112-day batch leaching experiment in Suwannee River fulvic acid solution and peat water (∼50 mg DOC l–1). The leaching was coupled with investigation of the secondary phases (SEM/EDS, Raman microspectrometry) and thermodynamic speciation-solubility modelling using MINTEQA2. Metals and As are released in large amounts during the early stage of the experiment, followed by a decrease in the concentrations in the leachate as a result of adsorption on secondary (hydrous) ferric oxides (HFO/FO), predicted by MINTEQA2 calculations and confirmed on the leached slag surface by SEM and Raman spectrometry. Compared to other contaminants, Zn exhibits more pronounced mobility and is adsorbed on HFO/FO only at pH >7. Such a scavenging process may be predominant during the long-term interaction of slag with an HMW organic solution of real soil. As a result, the soil cover and subsequent re-vegetation of slag dumps may be considered as a possible scenario for slag management.

The concentrations of the Al, Co, Cr, Cu, Pb, Sn, Ni, and Zn trace metals were monitored in Lake Ipê (Brazil) during twohydrological sub-periods : June - December 1999 (low water period, LW), and January - April 2000 (high water period, HW).A detailed study of the physical and chemical state of the metals was performed through the MINTEQA2 computer programusing 15 abiotic parameters. An increase in concentration of many trace metals in July 1999 was due to the sudden entry ofallochthonous matter. The seasonal study showed that the metal concentrations in the lake were governed by the hydrologicalregime of the Paran· River (HW), and by the occurrence of occasional flood pulses and rainfall (LW).