固定化微生物净化低浓度SO₂烟气工艺的研究

【作者】 武淑文；

【导师】 黄兵；

【作者基本信息】 昆明理工大学 ， 环境工程， 2004， 硕士

【摘要】 燃煤引起的SO₂问题是当前国际上最关注的热点环境之一，它不仅造成严重的环境污染，且是引起酸雨的主要物质。我国是世界上唯一以煤为主要能源的国家，是世界SO₂排放的第一大国，如不严格控制，SO₂问题将成为制约我国国民经济发展和社会发展的重要因素。目前对SO₂气体常用的处理方法多为物理和化学方法，虽然处理效果好，但成本较高，存在二次污染等问题，相比之下生物法具有运行成本低，能耗少，二次污染少等优点。 固定化微生物技术具有微生物密度高、反应迅速、微生物流失少、产物易分离、反应过程易控制的优点，而成为当前研究的热点。本课题采用固定化微生物法净化SO₂气体。实验内容包括：①脱硫菌最佳驯化工艺条件的研究；②固定化微生物的制备条件和性能研究；③固定化微生物降解SO₂的工艺研究；④固定化微生物脱硫机理初探。 实验采用诱导驯化方式对菌种进行驯化，最佳驯化工艺为：营养物质投加量为17.5ml／L菌种，供氧速率为0.4L／min，曝气时间为30min，间歇时间为60min，此时驯化菌种具有最佳的净化效率和降解速率。 实验研究了固定化微生物在不同环境条件下的性能，结果表明：固定化后的微生物对热、pH值等的稳定性提高，对有毒物质的毒性抵抗力增强。在相同条件下，固定化微生物的生物降解性能明显高于游离微生物。固定化微生物在生化反应器连续运行60天，活性未出现下降趋势，一直保持较好的机械强度。 固定床生化反应器净化SO₂气体的工艺研究表明，在无喷淋液、气体停留时间为5s、SO₂气体的入口浓度低于5g／m³时，其净化效率可达95％。系统连续运行3个小时后采取喷淋液体并通入空气的方式可恢复整个系统的净化能力。 本实验不仅为低浓度SO₂烟气的生物治理提供了一条新途径，而且还拓展了生物技术在废气治理领域的研究与应用。更多还原

【Abstract】 The problem about air pollution caused by sulfur dioxide from coal burning is one of the focus issues concerned by all over the world. SO2 not only brings seriously air polluted but also causes acid rain for its water-solubility. China is the country where coral is the primary energy sources, the pollution problem caused by SO2 will become the important factor which limits the development of national economy and society if it is not strictly controlled. At present, the mostly physical or chemical method with high removal rate treating SO2 has a few disadvantages of high cost and second pollution, but Biological method has many advantages of low cost, few energy sources needed and little second pollution.Immobilized microorganism technique with high concentration, fast reaction rate, less loss of microorganism and easy control has become the focus researched. In present, the research on biological method treating SO2 is little in the world. The immobilized microorganisms technology treating SO2 flue gas has been discussed in this thesis. The project concludes the following:1. To study in the optimal domesticated condition on microorganism treating SO2.2. To study in preparation condition and degradation capability on immobilized microorganism cell.3. To research process treating sulfur dioxide by biochemical reaction system.4. To study mechanism of desulfurization by immobilized microorganism.Using induced domesticating method, the bacteria with strong SO32- " degradation capacity can be cultivated in the waste water. With high of degradation ratio and rapid of degradation rate, the optimal domesticating condition is: rate of oxygen supply 0.4L/min, aeration time 30mine, retention time 60min, quantity of nutrient 17.5ml/L microorganism.The experiment on performances of immobilized microorganism in different conditions showed that the optimal pH value and temperature range of SO32- degradation by immobilized microorganism were bigger than that of SO32- degradation by suspended microorganism. Immobilized microorganism had more resistence to poisonous substance such as heavy metal ion than that of suspended microorganism. In the same condition, biodegradation rate and enzymatic activity of immobilized microorganism are greater than that of suspended microorganism. When packed-red bioreactor had worked continuously 60 days, the strength change ofimmobilized cells was little, and activity of immobilized microorganism was not reduced.The SO2 removal experiment in packed-red bioreactor proved that the removal efficiency of system was above 98% in the absence of spay liquid, with the gas retention time 5s and concentrated of SO2 below 5g/m3. Additionally, the system saturated after continuous treating 3 hours, the biodegradation capacity of the system can be regenerated by washing and aerating. The whole research indicated the feasibility of immobilized microorganism technique degradation SOj.The experiment results not only show a new way for biological low concentration flue gas desulfurization, but also provide a potential application and study in waste gas treatment by biological technology.更多还原