Leachability of metals and natural radionuclides in columns of tropical soils amended with phosphogypsum

• Grant number: 10/10587-0
• Support Opportunities: Regular Research Grants
• Start date: August 01, 2011
• End date: January 31, 2014
• Field of knowledge: Engineering - Nuclear Engineering - Applications of Radioisotopes
• Principal Investigator: Barbara Paci Mazzilli
• Grantee: Barbara Paci Mazzilli
• Host Institution: Instituto de Pesquisas Energéticas e Nucleares (IPEN). Secretaria de Desenvolvimento Econômico (São Paulo - Estado). São Paulo , SP, Brazil
• Associated researchers: Catia Heloisa Rosignoli Saueia ; Godofredo Cesar Vitti ; Marcelo Bessa Nisti

Abstract

Natural radionuclides of U and Th series are present in many natural sources. High concentrations of these elements are found in geologic materials, rocks and minerals. Human activities may cause a significant increase in concentration of these elements, defined as TENORM, and a potential increase of exposure to natural radiation in products, by-products and waste. Important examples of this situation in Brazil are the phosphate fertilizers industries, responsible for the production of a residue called phosphogypsum. This residue concentrates natural radionuclides of U and Th series and metals present in the phosphate rock used as raw material.The phosphogypsum can be used as a soil amendment, since it presents high solubility, can improve the soil structure for tillage, reduce the soil erosion, increase sulphur and phosphorus availability and improve the composition of the fertilizers. Presently, the phosphogypsum produced has been stored in stacks, since there is no comprehensive regulation related to its safe use and environmental impact; furthermore, its levels of impurities are not completely established. Therefore, the objective of this work is to study the bioavailability of the natural radionuclides (238U, 232Th, 226Ra, 228Ra e 210Pb) and the elements (As and metals Cd, Cr, Hg and Pb) present in the Brazilian phosphogypsum, by leaching EDTA solution in columns containing soil tiled with phosphogypsum. This procedure allows reproducing in the laboratory the field conditions. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

ROSIGNOLI SAUEIA, CATIA HELOISA; NISTI, MARCELO BESSA; CARDOSO DA SILVA, PAULO SERGIO; DE OLIVEIRA, JONATHAN PEREIRA; MAZZILLI, BARBARA PACI. Lixiviation of rare earth elements in tropical soils amended with phosphogypsum. INTERNATIONAL JOURNAL OF ENVIRONMENTAL ANALYTICAL CHEMISTRY, v. 100, n. 6, JULY 2019. (10/10587-0)

NISTI, M. B.; SAUEIA, C. R.; MALHEIRO, L. H.; GROPPO, G. H.; MAZZILLI, B. P.. Lixiviation of natural radionuclides and heavy metals in tropical soils amended with phosphogypsum. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY, v. 144, p. 120-126, JUN 2015. (10/10587-0)