Polonium-210 distribution in Syrian phosphogypsum

Polonium-210 distributions in Syrian phosphogypsum and its leaching mechanisms have been evaluated. Radiochemical analyses have shown that Po-210 concentration in Syrian phosphogypsum is always higher than Ra-226 concentration. Po-210 concentrations were found to vary between 373 and 589 Bq.kg(-1) with an average value of 471 Bq.kg(-1), which is lower than values reported in other countries. Po-210 was found to be more concentrated in smaller particles; a specific activity of 827 Bq.kg(-1) in particles less than 250 mesh was observed. Leaching experiments using distilled water have shown that Po-210 are strongly bounded to phosphogypsum particles. The amount of Po-210 transferred to aqueous media does not exceed 5.6% and 8.4% for batch wise and continuous leaching, respectively; lowering the pH has increased this percentage to 20%. In addition, leaching with diluted sulfuric acid indicated that 80% of polonium is present as water insoluble quadrivalent polonium sulfate while 20% as soluble simple polonium sulfate. However, the obtained data could be used to explain environmental pathways of Po-210 from phosphogypsum.