Experimental Evaluation of Indigenous Fungal Isolates for the Biobeneficiation of Nigerian Iron Ore: Mineralogical and Chemical Evidence

Abstract

Aims: The study aimed to evaluate the ability of indigenous fungal isolates (Aspergillus ochraceus, Aspergillus nomius, and Penicillium citrinum) to improve the quality of Nigerian iron ore by removing impurities such as alumina, silica, manganese oxide, and phosphorus. Study Design: This was an experimental laboratory study using a completely randomised design with four treatments (three fungal isolates and one uninoculated control) over an eight-week incubation period. Place and Duration of Study: The research was conducted in the Department of Microbiology, Chukwuemeka Odumegwu Ojukwu University, Anambra State, Nigeria, using Nigerian iron ore samples over eight weeks. Methodology: Iron ore samples were inoculated with the fungal isolates and incubated under controlled conditions. pH measurements were taken at two-week intervals, and elemental compositions were analysed before and after incubation using X-Ray Fluorescence (XRF) and Atomic Absorption Spectrophotometry (AAS). Statistical analyses included regression, ANOVA, the Shapiro–Wilk normality test, and homoscedasticity testing. Results: Aspergillus ochraceus achieved the highest overall mass removal (66.51%) and the greatest reduction in phosphorus (99.72% by XRF). Penicillium citrinum showed the highest phosphorus removal efficiency by AAS (79.15%). Aspergillus nomius was most effective in removing manganese oxide (95.98%). Incubation time significantly affected pH (F = 13.35, p = 0.006), and the interaction between fungal species and time was also significant (F = 5.39, p = 0.025). Statistical assumptions of normality and homoscedasticity were satisfied. Conclusion: Indigenous fungal isolates, especially Aspergillus ochraceus, can effectively improve Nigerian iron ore quality by selectively removing gangue minerals and phosphorus. The findings support the potential of fungal biobeneficiation as an environmentally friendly alternative to chemical beneficiation, with pilot-scale validation needed before industrial application.