Surface alteration of realgar (As4S4) by Acidithiobacillus ferrooxidans Authors Peng Chen Lei Yan Qiang Wang Yang Li Hongyu Li Abstract The chemical and physical characteristics of realgar (an arsenic sulfide mineral that occurs in several crystalline forms) in the presence of Acidithiobacillus ferrooxidans BY-3 were investigated in this work. Grains of the mineral were incubated for 10, 20, and 30 days with A. ferrooxidans cultured in 9K medium at 30 °C and at 150 rpm agitation. Abiotic control experiments were conducted in identical solutions. The effect of bioleaching on the surface properties of realgar was characterized by scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), inductively coupled plasma atomic emission spectroscope (ICP-AES), X-ray diffraction (XRD), and Raman spectroscopy. SEM and EDS analyses confirmed the ability of A. ferrooxidans to modify surfaces of realgar and to efficiently enhance its dissolution. ICP-AES showed the dissolution and precipitation of realgar during bioleaching. Based on the XRD pattern and the Raman spectra, the decrease in arsenic in the liquid phase was due to co-precipitation of the mineral with Fe(III) or Fe(III) compounds (e.g., jarosite or goethite). Thus, not only did Fe(III) alter the surface of realgar, but it also promoted its dissolution during bioleaching. Downloads PDF Published 2012-05-14 Issue Vol. 15 No. 1 (2012) Section Research Articles License Submission of a manuscript to International Microbiology implies: that the work described has not been published before, including publication in the World Wide Web (except in the form of an Abstract or as part of a published lecture, review, or thesis); that it is not under consideration for publication elsewhere; that all the coauthors have agreed to its publication. The corresponding author signs for and accepts responsability for releasing this material and will act on behalf of any and all coauthors regarding the editorial review and publication process.If an article is accepted for publication in International Microbiology, the authors (or other copyright holder) must transfer to the journal the right–not exclusive–to reproduce and distribute the article including reprints, translations, photographic reproductions, microform, electronic form (offline, online) or any other reproductions of similar nature. Nevertheless, all article in International Microbiology will be available on the Internet to any reader at no cost. The journal allows users to freely download, copy, print, distribute, search, and link to the full text of any article, provided the authorship and source of the published article is cited. The copyright owner's consent does not include copying for new works, or resale. In these cases, the specific written permission of International Microbiology must first be obtained.Authors are requested to create a link to the published article on the journal's website. The link must be accompanied by the following text: "The original publication is available on LINK at <http://www.im.microbios.org>. Please use the appropiate URL for the article in LINK. Articles disseminated via LINK are indexed, abstracted, and referenced by many abstracting and information services, bibliographic networks, subscription agencies, library networks, and consortia.