ZHANG Rui, LU Xian-cai, LIU Huan, LI Juan, XIANG Wan-li, CHEN Xiao-ye

Key Lab of Surficial Geochemistry, Ministry of Education, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, China

Abstract: The gossan of Wujiashan, Wushan, Jingxi, and the synthesized goethite were employed to react with a well-known dissimilatory iron reducing bacteria, Shewanella oneidensis MR-1, to disclose the geochemical behavior of heavy metals during the reduction process and to further understand the mechanism of microbial reduction of trivalence iron minerals. The changes in solution chemistry and mineral components were investigated using various methods of o-phenanthroline method, ICO-OES, SEM, TEM, XRD, FTIR and so on. The release of Fe2+ and Fe3+ ions into the solution revealed that the ferric minerals were reduced and various heavy metals were released. Due to the influences of secondary minerals and bacteria cells, different heavy metals exhibited various behaviors. The released manganese and arsenic were re-fixed into secondary minerals, while zinc, copper and lead were adsorbed onto the surface of bacteria cells. Meanwhile, the reduction of ferric minerals was detected in the group inoculated with killed cells, which indicated that the organic matter also can promote the reducing of ferric minerals.

Keywords: dissimilatory iron reducing heavy metals gossan Shewanella oneidensis MR-1

*Corresponding Author, E-Mail: zcn@petrochina.com.cn

Bulletin of Mineralogy, Petrology and Geochemistry Vol. 34, No.2, 2015, page 316-322