During the acidulation process the radioactive equilibrium within the phosphate rock is disrupted and radionuclides are partitioned according to their solubility Isotopes of U and Th partition primarily into the phosphoric acid while isotopes of Ra and Po partition into the phosphogypsum Roessler et al 19791; Radioactivity and elemental
The radioactivity of the measured samples induced mainly by the radium 226 isotope is of the order of 40 8750 Bq/kg corresponding to a relatively low content in radioactive elements U =
Trails were performed for the recovery of group trace elements including the radioactive elements partitioned with the phosphogypsum PG stockpiled in around 12 million tones at Al Qaim in
Phosphogypsum a by product of phosphate fertilizer production is produced in large quantities worldwide Natural abundances and mineralogical partitioning of trace elements in selected Alberta soils Canadian Journal of Soil Science 60 763 771 Google Scholar Montgomery Alabama Eastern Environmental Radiation Facility
Phosphoric acid manufacturing generates large amounts of phosphogypsum PG ; a by product generally disposed in the surface or evacuated in the seawater without any pretreatment Phosphogypsum may host non negligible amounts of valuable elements such as rare earth elements REEs which are critical elements on the global market Surface disposal
Phosphogypsum PG accumulates during wet phosphoric acid production for fertilizers In the Philippines PG is partly 40% utilized to produce gypsum walls and cement This work assesses the radiological risks and resource opportunities associated with PG stacks in the Philippines The conducted in situ radiometric survey measured the activity concentrations
For the Russian Federation an urgent issue is the search for new raw materials sources of rare earth elements REE [1 2] Phosphogypsum a large tonnage product of apatite processing in the production of extraction phosphoric acid for mineral fertilizers can serve as one of the promising sources of REE [3 7] In addition to rare earth elements phosphogypsum
Usually PG contains radioactive elements The radioactivity of PG in particular α is due to the radium content resulting from the decomposition of uranium present in the phosphate ore The resulting radiation dose caused by phosphogypsum used as a construction or plaster material can be considered to be negligible [18 19]
An assessment of the main radioactive sources natural and artificial radionuclides existing Volume 9 • Issue 1 • 363 Citation Madruga MJ Prudencio MI Gil Corisco JA Mihalik J Marques R et al 2019 Distribution of Natural Radionuclides Rare Earth Elements Metals and Metalloids in a Phosphogypsum Stockpile
Humans are constantly exposed to radioactivity present in rocks soils and water mainly from materials in the Earth s crust that contain chemical elements belonging to the radioactive series of uranium and thorium An important anthropogenic source of these natural radioisotopes to the environment is fertilizers widely used to increase agricultural productivity
The removal of radioactive elements and toxic heavy metals from contaminated sources is a worthwhile priority for environmental protection initiatives Therefore researchers have concentrated on the extraction of U from its ores using microorganisms for bioremediation and bioleaching [ 49 50 ]
Phosphogypsum contains trace elements and naturally occurring radioactive materials which may be hazardous to the surrounding environment In addition the evaluation of radioactive elements
Radioactive impurities of phosphogypsum The activities and concentrations of different radionuclides in PG vary with the origin of the rock used in the phosphate industry Table 3 [18]
To elaborate about 80% or radium is concentrated in phosphogypsum while almost 86% and 70% of uranium and thorium respectively are concentrated in phosphoric acid instead Tayibi et al 2009 This has therefore raised concerns about the leaching of radioactive elements in disposal sites as well as the release of radon gas into the atmosphere
Phosphogypsum is a by product from the phosphate fertilizer industry disposed in huge stacks in open air storage areas Its use in agriculture may be a solution to decrease these stacks because
radioactive elements The increasing world agricultural demand is the real responsible for the severity as is the case of the elements present in phosphogypsum This protocol simulates the
Phosphogypsum PG is the main by product of phosphoric acid which is produced by the sulfuric acid attack of phosphate rocks wet process This by product which contains around % phosphoric acid is used as a low cost soil fertilizer PGF PGF consists mainly of gypsum CaSO4·2H2O P2O5 SiO2 and other impurities including a minor amount
It goes through a chain of seven more transformations into unstable elements before reaching stability A common unit of activity is the curie named after Marie and Pierre Curie who discovered radium Radiation and Phosphogypsum; Radiation and Phosphoric Acid; Radioactivity and Phosphatic Clay Ponds; Phosphate Companies and EPA s Toxic
Azouazi et al were probably the first to provide a systematic analysis of the radioactivity found in Moroccan Khouribga phosphate rock resulting phosphogypsum and potential transfer of the radioactive elements into groundwaters from dry stacking the phosphogypsum on land when this practice was still used in Morocco
Chemosphere Nanominerals assemblages and hazardous elements assessment in phosphogypsum from an abandoned phosphate fertilizer industry Chemosphere 256 Chmutov s legacy in developing the fundamental concepts of the radioactive elements chromatography Russ J Phys Chem A 94 2020 pp 459 464
Because the radionuclides within phosphogypsum are a source of radon gas and direct gamma radiation the EPA regulates phosphogypsum as a source category of radionuclides under the Clean Air Act Phosphogypsum stacks additionally contain low pH process water and heavy metals as a result of the wet acid fertilizer production process The
The radioactive elements such as 237Np 239Pu 241Am 99Tc and 90Sr are soluble and contaminate groundwater so ocean dumping and/or deep bored wells of radioactive waste containing these radioactive elements are not safe disposal methods The reduced form of these radioactive elements is insoluble immobilized and gets precipitated
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