Study On The Characteristics Of Ferromanganese-oxidation Bacteria In Pyrolusite Flue Gas Desulphurization

Flue gas desulphurization is a rising sort of desulphurization techniques using the primary components MnO2 and Fe2O3 of pyrolusite as catalyzers. Therefore, it is critical for these catalyzers to renew and regenerate in this process. At present some traditional methods, such as electrochemistry, chlorate reagent (chlorate natrium or H2O2) etc. were applied to oxidization and regeneration of Mn (II ) and Fe (II ), the expensive cost, however, limited their application to the practical process of the pyrolusite desulphurization. The ability of ferromanganese-oxidation bacteria in the nature to oxidize manganese and iron from bivalent state to hexavalent state and bivalent state to trivalent state respectively has been paid more attention recently because it is possible to make pyrolusite regenerate and the process of pyrolusite desulphurization proceed continuously.The oxidation efficiency of ferromanganese-oxidation bacteria to oxidize Mn (II) and Fe (II ) depends on the bacterial survival conditions, hence, different environmental conditions need be observed so that valuable references will be provided for its practical application if pyrolusite is oxidized by microorganisms. In this paper, we study the oxidization efficiency of pure and mixed ferromanganese-oxidation bacteria separated from the mine and thermal spring water in Sichuan province to oxidize Mn ( II ) and Fe (II) under different temperature, pHand rotate speed of shaker bed.The study results indicated that the optimal temperature, pH and rotate speed for pure Thiobacillus ferrooxidans to get the biggest oxidization efficiency in the 9k culture were 30℃, pH=3 and 100 r/min respectively. Fe (II) will be totally oxidized in 48h and the largest oxidization rate is l.23g'L^'h"1 under this condition. The optimal temperature, pH and rotate speed for pure Manganese-oxidization bacteria to get the biggest oxidization efficiency in the nutrient solution were 30℃, pH=6 and 150r/min respectively. 86.7 percent of Mn (II) will be oxidized in 4 days and the largest oxidization rate is 13.78mg*L'1*h"1 under this condition. Whereas 100% oxidization efficiency of Fe (II) for mixed bacteria primarily including Thiobacillus ferrooxidans and Manganese-oxidation bacteria will be achieved in 9k culture at 30℃ pH=3 and rotate speed=100 r/min in 72 hours. While 77.7% manganese (II) will be oxidized by mixed bacteria in the manganese nutrient solution in 4 days, which is lower than that of pure manganese-oxidation bacteria. In the solution of MnSO4 and FeSO4 without other nutrient elements, 100% of Fe (II) and 53.1% Mn (II) will be oxidized by mixed bacteria at 30℃, pH 2-3 and rotate rate 100-150 r/min in 96 hours and 4 days respectively.These study results are very weightily basic data for putting ferromanganese oxidation-bacteria into the process of flue gas desulphurization and are provided with definitely practical sense and reference value!...