pyromorphite and fluorapatite

Phosphate-solubilizing fungi (PSF) can secrete large amounts of organic acids. In this study, the application of the fungus Penicillium oxalicum and geological fluorapatite (FAp) to lead immobilization was investigated. The formation and morphology of the lead-related minerals were analyzed by ATR-IR, XRD, Raman, and SEM. The quantity of organic acids secreted by P. oxalicum reached the maximum on the fourth day, which elevated soluble P concentrations from 0.4 to 108 mg/L in water. The secreted oxalic acid dominates the acidity in solution. P. oxalicum can survive in the solution with Pb concentration of ~ 1700 mg/L. In addition, it was shown that ~ 98% lead cations were removed while the fungus was cultured with Pb (~ 1700 mg/L) and FAp. The mechanism is that the released P from FAp (enhanced by organic acids) can react with Pb

Topics: Apatites; Aspergillus niger; Biodegradation, Environmental; Lead; Microscopy, Electron, Scanning; Minerals; Oxalates; Penicillium; Phosphates; Phosphorus; Solubility; Spectrophotometry, Infrared; Spectrum Analysis, Raman; Water Pollutants, Chemical; Water Purification; X-Ray Diffraction