Growth models of the continuous bacterial leaching of iron pyrite by Thiobacillus ferrooxidans
In recent years there has been increasing interest in the bacterial leaching of low grade metal ores and the bacterial leaching of pyritic sulfur from coal. The leaching of iron pyrite by Thiobacillus ferrooxidans was studied in a continuous stirred tank reactor at a variety of dilution rates (0.012-0.22 h/sup -1/), pyrite surface areas (18-194 m/sup 2//L), and inlet soluble substrate (Fe/sup 2 +/) concentrations (0-3000 ppm). The bacterial leaching rate was found to increase with increasing pyrite surface area, dilution rate, and inlet Fe/sup 2 +/ concentration. The concentration of bacteria in solution was related to the concentration of bacteria attached to the pyrite surface by a Langmuir-type adsorption desorption relation. Fitting the experimental data to this relation yielded a value for the area occupied per bacterium of 86 ..mu..m/sup 2/. This result is consistent with the concept of preferential bacterial attachment to certain sites on the solid. A bacterial growth model was developed that included both bacterial growth in solution and growth of bacteria attached to the pyrite surface. The specific growth rate of attached bacteria was calculated from this model and was found to increase with increasing solid dilution rate and to decrease with increasing pyrite surface area and soluble substance concentration. An explanation of these results based on an active-inactive site mechanism was also developed. (JMT)
- Research Organization:
- Georgia Inst. of Tech., Atlanta
- OSTI ID:
- 6930279
- Journal Information:
- Biotechnol. Bioeng.; (United States), Vol. 24:4
- Country of Publication:
- United States
- Language:
- English
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PYRITE
LEACHING
SULFUR
BIODEGRADATION
COAL
GROWTH
IRON ORES
MATHEMATICAL MODELS
PURIFICATION
THIOBACILLUS FERROXIDANS
BACILLUS
BACTERIA
CARBONACEOUS MATERIALS
CHALCOGENIDES
CHEMICAL REACTIONS
DECOMPOSITION
DISSOLUTION
ELEMENTS
ENERGY SOURCES
FOSSIL FUELS
FUELS
IRON COMPOUNDS
IRON SULFIDES
MATERIALS
MICROORGANISMS
MINERALS
NONMETALS
ORES
SEPARATION PROCESSES
SULFIDE MINERALS
SULFIDES
SULFUR COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
550700* - Microbiology
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