Fungal Leaching of Uranium from its Geological Ores in Alloga Area, West Central Sinai, Egypt

Abstract

Seven fungal species were isolated from two uranium ores in Alloga region, west central Sinai, Egypt. They were identified as, Aspergillus flavus, Penicillium brevicompactum, P. oxalicum, P. purpurescens, P. lividum, Aspergillus terreus and P. spinulosum. They were tested for bioleaching activity of uranium from its ores, A. terrus and P. spinulosum showed a high leaching activity. The growth of these fungi highly affected by the presence of the ore in the growth media. The amount of uranium solubilized by A. terreus and P. spinulosum was increased with increasing ore concentrations in the growth media, reaching its maximum at 4%(w/v). Whereas, the highest percentage of uranium released by both fungi was obtained at 1%(w/v), at this concentration the released uranium being 75 and 81.5% respectively for ore (OS1) and 72.8 and 77.6% respectively for the second ore (OS2). The best leaching occurs when the final pH shifts toward acidity. The biosorption of released uranium by the fungal mycelium was also increased with increasing ore concentrations in the growth media. One gram dry mycelium of A. terreus and P. spinulosum could bind approximately 9.6 and 14.2% respectively, at 1% of OS1 and 10.8 and 17% respectively, at the same concentration of OS2 from the total uranium solubilized during bioleaching process.