【作者】 童小双；

【导师】 蒋文举；

【作者基本信息】 四川大学 ， 环境工程， 2005， 硕士

【摘要】 烟气脱硫技术是SO₂污染控制的重要技术手段,而生物烟气脱硫技术以其操作条件简单,运行费用低廉,无二次污染等优点成为超越传统烟气脱硫技术的一个新的技术发展方向。 氧化亚铁硫杆菌因其具有双重氧化性能成为生物脱硫最重要的菌种之一。目前对生物脱硫的研究大多仍停留在机理探讨阶段,本文研究旨在氧化亚铁硫杆菌脱硫的理论分析基础上,通过考察不同反应条件对脱硫效率和产酸过程的影响,弄清氧化亚铁硫杆菌催化氧化吸收SO₂的反应机理和最优工艺条件,初步建立脱硫过程的动力学模型,以推进生物脱硫技术的实质性进展。 通过对照水溶液、含Fe²⁺水溶液、含Fe³⁺水溶液、细菌溶液、细菌培养基水溶液对二氧化硫的脱除,表明氧化亚铁硫杆菌具有直接氧化和间接催化氧化SO₂的作用,氧化亚铁硫杆菌可以直接将低价硫化物氧化成SO₄^2-;同时在酸性条件下,可以氧化Fe²⁺成Fe³⁺,增强Fe对SO₂的液相催化氧化能力。通过进一步的单因子实验,对各操作条件对脱硫和产酸的影响进行了细致研究,结果表明,脱硫率随初始Fe³⁺浓度、初始Fe²⁺浓度、进口SO₂浓度、反应温度等操作条件的影响比较大,只有在适宜的温度（30℃～40℃）和pH值下,脱硫效果才比较理想,因此筛选和培育出适应性和稳定性更强的氧化亚铁硫杆菌,对提高脱硫效果非常有必要;同时初始Fe³⁺和Fe²⁺浓度越高,脱硫效果越好,表明氧化亚铁硫杆菌间接催化氧化SO₂作用占主导地位。 本文提出了氧化亚铁硫杆菌和Fe³⁺协同催化氧化SO₂的产酸动力学方程: r=d[SO₄^2-]/dt=11.23×10^-5[Fe³⁺]^0.35[SO₄^2-]^0.05更多还原

【Abstract】 FGD （Flue Gas Desulfurization） is one of the most important methods for SO₂ pollution controlling. Flue Gas Desulfurization by microorganism, with advantages of flexible operational conditions, low cost, no secondary pollutions, etc., will be a new developing direction of FGD technologies.T.f （Thiobacillus ferrooxidans） is one of the most important bacteria species in biological desulfurization for its dual oxidation property. In the recent, most of the studies are still focused on the theoretical study. Based on biologically desulfurizing theory, this paper studied the effects of different reaction conditions to desulfurizing efficiency and acid-producing action, the reaction mechanisms of catalytic oxidation of SO₂ by T.f, the optimal reaction conditions and the reaction kinetics, for prompting biological desulfurizing technology to a great progress.Contrasting desulfurizing effects of pure water, water containing Fe²⁺, water containing Fe³⁺, bacteria liquor and bacterium culture medium liquor, it can be conclude that T.f has the capacities of direct biologic oxidation and indirect catalytic oxidation property to SO₂, T.f can directly oxidize low-valence sulfur into SO₄^2-, meanwhile, under acid conditions, can quickly oxidize Fe²⁺ into Fe³⁺ which increase the catalytic oxidation capacity of SO₂. After further study on single factor-based experiments, the results indicated that desulfurization rate can be affected by the operational conditions, such as the initial concentration of Fe³⁺, the initial concentration of Fe²⁺, the concentration of SO₂, the reaction temperature, and the ratio of liquid and gas etc., Perfect desulfurization effect can be only obtained in proper temperature （30℃⁴0℃） and pH. So, selecting and taming more adaptiveand steady T.f is absolutely necessary to increase desulfurization effect. The higher initial concentration of Fe3+and Fe2+, the more effective of desulfurization, which shown that indirect catalytic oxidation by T.f play dominate role in the process of catalytic oxidation of SO2.In the end, a reaction kinetics equation that can be used in the system of T.f and Fe3+ cooperative catalytic oxidation of SO2 is given out:2--r = d[S°4 ] = 11.236x 10-5[Fg3+]035[S<942-]005 dtThe given equation can effectively describe acid-producing characteristics, with the existence of T.f, in the process of Fe catalytic oxidation of SO2.更多还原