Remediation of Lead Contamination by Aspergillus niger and Phosphate Rocks under Different Nitrogen Sources

Co-application of Aspergillus niger (A. niger) and phosphate rocks (PR) has been practiced by environmentalists for lead (Pb) remediation. The secretion organic acid A. usually dominates the dissolution PR Pb immobilization. In this study, two types (fluorapatite (FAp) phosphogypsum (PG)) were investigated in remediation under three different forms nitrogen (ammonium, nitrate, urea). Our results reveal that formation pyromorphite oxalate contributed to removal combination with FAp PG. PG showed a significant capability compared FAP, over 94% vs. 50%. Compared nitrate urea, ammonium significantly decreased cation concentrations from 1500 mg/L 0.4 mg/L. Due containing sulfate, sulfate formed also removal. However, stimulated secrete more oxalic (~1400 mg/L) than urea (~200 mg/L), which can form insoluble oxalate. These minerals reduce availability removed Pb. Despite efficacy both remediation, our findings suggest is primary candidate regard due high secretion.