Phosphogypsum biotransformation by aerobic bacterial flora and isolated Trichoderma asperellum from Tunisian storage piles

• Published in: Journal of hazardous materials Vol. 308; pp. 362 - 373
• Main Authors: Jalali, Jihen, Magdich, Salwa, Jarboui, Raja, Loungou, Mouna, Ammar, Emna
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 05-05-2016
• Subjects: Aerobic bacteria; Bacteria; Bacteria, Aerobic - metabolism; Biodegradation, Environmental; Biotransformation; Cadmium; Calcium Sulfate - metabolism; COD Reduction; Culture; DNA, Fungal - genetics; Enrichment; Fungi; Heavy metals; Metals, Heavy - metabolism; Phosphogypsum; Phosphorus - metabolism; Tamarix; Trichoderma; Trichoderma - genetics; Trichoderma - growth & development; Trichoderma - metabolism; Trichoderma asperellum; Tunisia; Zinc; PG; COD Reduction; Aerobic bacteria; COD; Phosphogypsum; EC; Trichoderma asperellum; Heavy metals
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2016.01.063

•The enrichment culture on PG enabled the development of microorganisms.•The isolated Trichoderma asperellum grew on PG concentration at 200gL−1.•At 200gL−1PG concentration, the experimented strain reduced COD by 52.32%.•Metals concentrations reduction reached a maximum of 73% for the zinc.•Trichoderma asperellum is an efficient microorganism for PG bioremediation.
Aerobic microorganisms able to grow on phosphogypsum (PG), characterized by heavy metals accumulation and high acidity were investigated by enrichment cultures. The PG was used at different concentrations, varying from 20 to 200g/L in the enrichment culture medium supplemented with compost and Tamarix roots. This treatment reduced COD and heavy metals PG concentration. An efficient isolated fungus, identified by molecular approach as Trichoderma asperellum, was able to grow on PG as the sole carbon and energy sources at the different experimented concentrations, and to increase the culture media pH of the different PG concentrations used to 8.13. This fact would be the result of alkaline compound released during the fungus PG solubilization. Besides, the heavy metals and COD removal exceeded 52% after 7 days culture. At 200g/LPG concentration, the experimented strain was able to reduce COD by 52.32% and metals concentrations by 73% for zinc, 63.75% for iron and 50% for cadmium. This exhibited the T. asperellum efficiency for heavy metals accumulation and for phosphogypsum bioremediation.