ABSTRACT
Abandoned phosphogypsum (PG) stacks are often characterised by residual acidity and elevated concentrations of toxic elements and radionuclides. In most cases, the lack of a cover allows aerial transportation of fine particles, solubilization and migration of toxic and radioactive elements and finally results in contamination of nearby soils, surface- and groundwater. The most viable rehabilitation option involves the application of a vegetative cover, providing that several undesirable characteristics of PG are modified. In the present paper, the critical factors affecting rehabilitation of abandoned PG stacks, as derived from a field pilot application, are presented and discussed. These factors include modification of PG surface with the addition of amendments and nutrients (such as limestone, kaolin, bentonite or sewage sludge), establishment of an active soil microbial community in the roots microenvironment and selection and planting of suitable perennial species and bushes exhibiting low toxic elements uptake.
