BIOLOGICAL LEACHING OF SHALES - A REVIEW
A. TASA
Institute of Molecular and Cell Biology
Tartu University
23 Riia, Tartu
51014, Estonia
O. H. TUOVINEN
Department of Microbiology
Ohio State University
484 West 12th Avenue, Columbus
Ohio 43210-1292, U.S.A.
| An overview of microbial technology for sulfur removal from shales is presented in
this paper. Sulfur removal from oil shales through bioprocessing can substantially reduce SO2 emissions from thermal
power plants that combust oil shales for energy production. Iron sulfides constitute the most significant inorganic
sulfur fraction in shales. There are several Fe- and S-oxidizing microorganisms that have potential for oxidizing iron
sulfides to soluble products in acid sulfate-containing solutions. Environmental factors that influence the activities of these organisms are discussed. The organic sulfur compounds in shale matrix are variable and complex. Microbiological transformations of the organic sulfur fraction are poorly understood and it is not clear whether they are amenable to shale bioprocessing. The paper summarizes previously published experimental studies where shales were contacted with bacteria for iron sulfide oxidation. Shales constitute a complex system of study because they contain several phases such as clay minerals, sulfides, organic matter, and carbonates that interact with each other and with microorganisms. |