Microbiological Leaching of Al from the Waste of Bayer Process by Some Selective Fungi

In present investigation the biological leaching of aluminum by isolated fungi from red mud, the main waste product of the alkaline extraction of Al from bauxite was studied. Biological leaching experiments were carried out using indigenous, date and orange specimen fungi, Aspergillus Niger, Penicillium simplicissimum notatum. Savored Dextrose chloramphenicol Agar (SDA) was used as medium for the selected fungi. All microorganisms were tested for acid-production and leaching capabilities of aluminum from red mud. Leaching tests were performed in 250 mL Erlenmeyer flasks at 28 °C and at 150 rpm under aseptic conditions. Preheating of red mud and its impact on leaching process was investigated. Indigenous specimen fungi were the most efficient of the fungal cultures; 2082 mg of Al2O3/l was solubilized at 15 % pulp density of red mud. The metal content of leaching solution was determined by using wet chemical and atomic absorption spectrophotometer.