Abstract
Potentially toxic elements (PTE’s) are of great concern in steel mill wastes. Therefore, in other to use them as potential fertilizers in soil, risk assessments are needed. Three steel mill wastes were tested as possible amendments for soils at six different doses (0; 0,5; 1; 2; 4; 8; 16 t ha-1): Phosphate mud (PM), Metallurgical press residue (MPR) and Filter press mud (FPM) during rice cultivation in a pot experiment in a Haplic Gleisol. Analysis on rice tissues, including roots, shoots, husk and grains were conducted and contents of Cu, Cd, Ni, Zn, Mn and Pb were assessed. Translocation and bioaccumulation factors were calculated for each element. In general, PTE’s are more accumulated in roots and greater contents of Zn and Mn were found, while the lowest ones were found for Pb, probably due to its lack of functional roles during plants development. Higher translocation was observed for Mn, which is associated to the redox conditions of rice cultivation and the high mobility of this element under this condition. Application of steel mill wastes can increase PTE’s bioavailability and translocation factors, especially PM, but all of the wastes reveal a high hazard index.
Removal of chloride from fly ash produced in hazardous waste incineration by leaching and displacement washing in a vertical filter press