氧化亚铁硫杆菌菌液脱除SO_2的实验研究

Experimental study on the removal of SO_2 by Thiobacillus ferrooxidans

对比了酸性水溶液、酸性Fe3+溶液、含Fe3+的氧化亚铁硫杆菌菌液的SO2脱除效果,分析了氧化亚铁硫杆菌在SO2脱除过程中的主要作用。结果表明:(1)在实验的进气SO2浓度范围内,酸性水溶液对SO2的吸收仅为物理吸收,反应进行到60min时,SO2脱除率均降至15%以下,溶液不再具有SO2脱除能力。(2)对酸性水溶液、酸性Fe3+溶液和含Fe3+的氧化亚铁硫杆菌菌液3种吸收液而言,在实验的进气SO2浓度范围内,进气SO2浓度越高,SO2脱除率越低;Fe3+初始质量浓度为4.44g/L时,SO2脱除效果较好。(3)氧化亚铁硫杆菌在SO2脱除过程中,直接氧化作用不明显,其主要作用是将Fe2+氧化为Fe3+,维持溶液中Fe3+的浓度,这种间接氧化的作用对SO2的有效脱除非常重要。

In this paper,the removal of SO2 from simulated flue gas was performed by using 3 absorption liquids of acid aqueous solution,acid Fe3＋ solution and Fe3＋ containing Thiobacillus ferrooxidans bacterium solution respec- tively. The SO2 removal efficiency of 3 absorption liquids was researched and compared, and the main function of Thiobacillus ferrooxidans during the desulfurization was analyzed. The result showed that the absorption of SO2 by acidic aqueous solution was just a physical absorption process in the experimental concentration range of SO2. The SO2 removal efficiency decreased to lower 15% after 60 rain of adsorption, after then, the acidic aqueous solution no longer had any desulfurization capacity. For the three kinds of absorption liquid,in the experimental 802 inlet concen- tration range, the higher the SO2 was, the lower the desulphurization efficiency became, and the best desulfurization ef- fecticiency was found when the initial Fe3＋ concentration was 4.44 g/L. In the desulfurization process by Thiobacillus ferrooxidans,the main function of Thiobacillus ferrooxidans was the oxidation of Fe2＋ to Fe3＋ , remaining the Fe3＋ concentration in the solution. The indirect oxidation was very important to the effective removal of SO2 while the di- rect oxidation had no obvious effect.