Utilization of phosphate rock as a sole source of phosphorus for uranium biomineralization mediated by Penicillium...

In this work, uranium(vi) biomineralization by soluble ortho-phosphate from decomposition of the phosphate rock powder, a cheap and readily available material, was studied in detail. Penicillium funiculosum was effective in solubilizing P from the phosphate rock powder, and the highest concentration of the dissolved phosphate reached 220 mg L^-1 (pH = 6). A yellow precipitate was immediately formed when solutions with different concentrations of uranium were treated with PO₄ ^3--containing fermentation broth, and the precipitate was identified as chernikovite by Fourier transform infrared spectroscopy, scanning electron microscope, and X-ray powder diffraction. Our study showed that the concentrations of uranium in solutions can be decreased to the level lower than maximum contaminant limit for water (50 μg L^-1) by the Environmental Protection Agency of China when Penicillium funiculosum was incubated for 22 days in the broth containing 5 g L^-1 phosphate rock powder.