title: Lixiviation of natural radionuclides and heavy metals in tropical soils amended with phosphogypsum.
abstract: The main phosphate industries in Brazil are responsible for the annual production of 5.5 million tons of a residue (phosphogypsum), which is stored in stacks. The presence of radionuclides and metals puts restrictions on the use of phosphogypsum in agriculture. To assure a safe utilization, it is important to estimate the lixiviation of the radionuclides ((238)U, (226)Ra, (210)Pb, (210)Po, (232)Th and (228)Ra) and metals (As, Cd, Cr, Ni, Se, Hg and Pb) present in phosphogypsum. For this purpose, an experiment was carried out, in which columns filled with sandy and clay Brazilian typical soils mixed with phosphogypsum were percolated with water, to achieve a mild extraction of these elements. The results obtained for the concentration of the radionuclides and metals in the leachate were low; giving evidence that, even when these elements are present in the phosphogypsum, they do not contribute to an enhancement of their content in water.
authors.affiliation: Instituto de Pesquisas Energéticas e Nucleares, Av. Prof. Lineu Prestes 2242, CEP 05508000 São Paulo, Brazil.
authors.forename: M B
authors.initials: MB
authors.lastname: Nisti
authors.affiliation: Instituto de Pesquisas Energéticas e Nucleares, Av. Prof. Lineu Prestes 2242, CEP 05508000 São Paulo, Brazil.
authors.forename: C R
authors.initials: CR
authors.lastname: Saueia
authors.affiliation: Instituto de Pesquisas Energéticas e Nucleares, Av. Prof. Lineu Prestes 2242, CEP 05508000 São Paulo, Brazil.
authors.forename: L H
authors.initials: LH
authors.lastname: Malheiro
authors.affiliation: Instituto de Pesquisas Energéticas e Nucleares, Av. Prof. Lineu Prestes 2242, CEP 05508000 São Paulo, Brazil.
authors.forename: G H
authors.initials: GH
authors.lastname: Groppo
authors.affiliation: Instituto de Pesquisas Energéticas e Nucleares, Av. Prof. Lineu Prestes 2242, CEP 05508000 São Paulo, Brazil. Electronic address: mazzilli@ipen.br.
authors.forename: B P
authors.initials: BP
authors.lastname: Mazzilli
mesh_terms: D000383:Agriculture; D001938:Brazil; D002133:Calcium Sulfate / Q000737:chemistry*; D052918:Environmental Restoration and Remediation; D019216:Metals, Heavy / Q000032:analysis*; D010758:Phosphorus / Q000737:chemistry*; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis*; D012990:Soil Pollutants, Radioactive / Q000032:analysis*
chemical_list: D019216:Metals, Heavy; D012987:Soil; D012989:Soil Pollutants; D012990:Soil Pollutants, Radioactive; C077769:phosphogypsum; D010758:Phosphorus; D002133:Calcium Sulfate
keywords: Heavy metals; Natural radionuclides; Phosphogypsum residue; Soil conditioner