微生物法液相氧化SO_2

Aqueous Oxidation of SO_2 with Microbial Method

通过对酸性水溶液、含Fe^3＋水溶液、含Fe^2＋水溶液、细菌菌液和细菌培养基水溶液脱除二氧化硫的实验，探讨了微生物液相氧化二氧化硫的途径以液相中SO4^2-浓度考察了Fe^3＋浓度、Fe^2＋浓度、进口SO2浓度以及温度对脱硫成酸的影响,微生物脱硫有2种机制：一是直接氧化作用，即氧化亚铁硫杆菌（Thiobacillus ferrooxidans）将S（IV）氧化成S（VI）；二是间接催化氧化，氧化亚铁硫杆菌在酸性条件下具有快速氧化Fe^2＋成Fe^3＋，增强Fe^3＋对SO2的液相催化氧化能力，研究表明微生物脱硫以间接催化氧化为主．在浓度0～1．2g／L之间，Fe^3＋和Fe^2＋浓度越高，脱硫效果越好，氧化亚铁硫杆菌表现出对Fe^3＋／Fe^2＋体系氧化SO2的强化效果，人口SO2浓度越高，细菌脱硫效率越低，但液相中SO4^2-浓度随进口SO2浓度增加变化不大．温度对微生物脱硫影响较大，最佳脱硫温度为30～40℃．

The desulfurizations in dilute sulfuric acid solution, acidic ferric solution, acidic ferrous solution, microbial solution （Thiobacillus ferrooxidans） and microbial culture medium solution were conducted to discuss biodesulfurization mechanism. The effect of Fe^3＋ concentration, Fe^2＋ concentration, SO2 concentration and temperature on biodesulfurization was examined on SO4^2- concentration in the solution. Biodesulfurization has two ways： direct oxidation and indirect oxidation. In direct oxidation, Thiobacillus ferrooxidans oxidize S（IV） to S（VI）. In indirect oxidation, Thiobacillus ferrooxidans can fast transform Fe^2＋ to Fe^3＋ in acidic conditions and then increase aqueous catalytic oxidation capacity of Fe^3＋ on SO2. It shows that indirect oxidation is the dominant way in biodesulfurization process. The desulfurization efficiency increase with concentration of Fe^3＋ or Fe^2＋ in the range of 0 ～1. 2 g/L. Thiobacillus ferrooxidans enforce oxidation of SO2 in Fe^3＋/Fe^2＋. system. The removal of SO2 decrease as concentration of SO2 increase, however, concentrations of SO4^2- in the solution do not vary much in different inlet concentrations of SO2. Temperature has important effect on biodesulfurization. The optimal operative temperature range is 30～40℃