STUDYING ANAEROBIOSIS IN A MODEL EXPERIMENT WITH KAOLIN

A stagnant moisture regime was modeled in kaolin containing a wide ran ge of ferric minerals from the Prosyanovskoe site. The dynamics of gro wth of the main physiological groups of microorganisms and changes in the physicochemical properties of kaolin were studied. Experiments pro ved the ability of the FeRed iron-reducing bacterium strain found in t he developing cenosis to reduce iron and synthesize magnetite; however , biogenic magnetite was not registered in the treated kaolin. Anaerob iosis resulted in formation of the thermodynamically unstable ferric h ydroxides: ferrihydrite 5Fe(2)O(3) . 9H(2)O, akaganeite beta FeOOH, an d a new ferric hydroxide modification that caused an increase in the o xalate-soluble iron from 1 to 10% of the total iron. A low-ordered pro tolepidocrocite crystallized to a regular lepidocrocite. A decrease in the chemogenic forms of goethite and hematite and an increase in the biogenic forms of these minerals developing over the ferrihydrite were noted.