In the Goiás State, several ultramafic massives, recognized as hotspots of biodiversity, are mined for Ni and the production of slag is estimated to be approx. 1.84 Mt/y for the Barro Alto project for instance. Slag and fly ash are mainly stored onto surrounding soils, which are, for the ultramafic ones, naturally-rich in Ni, or dumped into lakes. Moreover, the vegetation growing on this ecosystem is either tolerant to metals or Ni-(hyper)accumulating. The objectives are:
– to sample and characterize all the compartments of the soil – waste – organism – water continuum, representative of the natural and the impacted ultramafic ecosystem
– to identify and characterize the metal-bearing phases controlling the Ni and Fe mobility and availability