Rate Kinetics on Bioleaching of Realgar Mineral by Leptospirillum ferriphilum: Effects of Fe (II) Concentration

Abstract

Abstract:The eco-friendly method of metal extraction, bacterial leaching is gaining more important in bio-hydrometallurgical industry. It is a proven method and can be applied for leaching process of several metals. This study was aimed to determine the efficiency of arsenic leaching from realgar mineral using the bacteria, Leptospirillum ferriphilum. The experiments were carried out in shaker flask, at fixed parameters 180 rpm, 0.2% pulp density (PD), 313 K at an initial pH of the media 1.5. The energy source, Fe 2+ concentration was varied from 2−10 g/L. The effect of Fe 2+ concentration on the kinetics of arsenic extraction was investigated. The experiment results showed that leaching of arsenic was highly influenced by concentration of Fe 2+ used in the medium. The maximum of 74.42% As was leached after 30 days when using optimum of 6 g/L of Fe 2+. Kinetic studies showed that the maximum rate constant value, 1.3633 d 1, was observed when optimum concentration of energy source was used.