Effect of Applied Potentials on the Activity and Growth of Thiobacillus ferrooxidans

Natarajan, KA (1992) Effect of Applied Potentials on the Activity and Growth of Thiobacillus ferrooxidans. In: Biotechnology and Bioengineering, 39 (9). pp. 907-913.

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Abstract

The effect of applied DC potentials both in the positive and negative range, on the activity and growth of Thiobacillus ferrooxidans, is discussed. In general, application of positive potentials up to +1000 mV in an acid bioleaching medium was found to be detrimental to bacterial activity, while the impression of negative potentials enhanced both their activity and growth through electrochemical regeneration of ferrous ions and an increase in the biomass. Ferrous-ferric ratios in a bioleaching medium could be monitored through Eh measurements.Among the base sulfide minerals such as pyrite, chalcopyrite, and sphalerite, sphalerite could be selectively bioleached if an impressed potential of -500 mV (SCE) could be maintained in the leaching medium. Electrochemical bioleaching tests carried out under an applied potential of -500 mV with sphalerite in the presence and absence of noble minerals such as pyrite and chalcopyrite indicated enhanced zinc dissolution with negligible copper and iron in solution. Probable mechanisms and advantages of the electrochemical bioleaching process developed in the laboratory are outlined.

Item Type:	Journal Article
Publication:	Biotechnology and Bioengineering
Publisher:	John Wiley & Sons, Inc.
Additional Information:	The copyright belongs to John Wiley & Sons, Inc.
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	01 Feb 2007
Last Modified:	19 Sep 2010 04:21
URI:	http://eprints.iisc.ac.in/id/eprint/4060

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