Department of Metallurgy, Indian Institute of Science, Bangalore, India.
Biotechnol Bioeng. 1992 Apr 15;39(9):907-13. doi: 10.1002/bit.260390905.
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.
讨论了施加的直流电位（正值和负值范围）对嗜酸氧化亚铁硫杆菌活性和生长的影响。一般来说，在酸性生物浸出介质中施加高达+1000 mV 的正电位被发现对细菌活性有害，而施加负电位的印象则通过电化学再生亚铁离子和增加生物量来增强其活性和生长。生物浸出介质中的亚铁-铁比值可通过 Eh 测量进行监测。在黄铁矿、黄铜矿和闪锌矿等基本硫化物矿物中，如果在浸出介质中能够维持-500 mV（SCE）的外加电位，则可以选择性地进行闪锌矿的生物浸出。在施加-500 mV 外加电位的条件下，在有和没有贵金属矿物（如黄铁矿和黄铜矿）存在的情况下进行的电化学生物浸出试验表明，锌的溶解得到了增强，而溶液中铜和铁的含量可忽略不计。概述了实验室中开发的电化学生物浸出工艺的可能机制和优势。
