To study the ability of chemolithotroph bacteria in extracting copper from Sarcheshmeh copper ore, and also, to separate element sulphur, which is releasing into the environment as sulphur dioxide pollutant, the activity of two sulphur bacteria was studied and compared both in single and mixed cultures. Thiobacillus ferrooxidans (TF) and Thiobacillus thiooxidans (TT) were grown on 9K and Imai media respectively and equal amounts of culture solutions of each were added to mine ores containing %0.2, %0.3 and %0.4 copper. After sixty days of experiment, the results of measuring copper amount in the solutions by using atomic absorption spectroscopy showed that TF released more copper than TT and in the mixed culture of two bacteria copper amount was nearly less than those of TF media and significantly more than TT media. Element sulphur released by the activity of the bacteria was extracted by using CS2. The sulphur amounts in mixed and single cultures were significantly different. Sulphuric acid amount produced in the media was calculated based on the pH changes at the beginning and the end of experiment. The amount of the acid varied as the ore concentration changed. Bacteria count showed a positive correlation with copper amount released in the media. However, the number of TF was more than TT and TT+TF in mixed culture.
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