【作者】 刘春敬；

【导师】 何洪；

【作者基本信息】 北京工业大学 ， 环境工程， 2012， 博士

【摘要】 本研究采用立式和分期布液式两种结构形式的生物反应器进行了净化H₂S废气的研究。生物滴滤塔闲置后，采用生物强化的方法进行了立式生物滴滤塔的再启动实验。以稳态运行的生物滴滤塔中的优势菌群作为菌源，采用包埋方式进行微生物固定化研究，探索制备固定化小球的最佳工艺条件，并考察固定化小球的H₂S降解性能。采用PCR-DGGE技术进行了生物滴滤反应器的微生态学研究，并建立了基于“累积效应”的生物动力学模型。采用高营养刺激生长和液相降解底物“优胜劣汰”的复合挂膜方法启动反应器，仅需3天。立式生物滴滤塔在进气浓度为50³00mg·m^-3时，其最佳营养液喷淋量为6L·h^-1，停留时间高于15s时，滴滤塔保持90%以上的净化效率。最佳体积去除负荷为89.15g·（m³·h）^-1，最大体积去除负荷为135g·（m³·h）^-1。通过优化反应器布液布气，设计了气液两相呈错流接触的分期布液生物滴滤床。采用气液联合驯化方式，分期布液式生物滴滤床能够在3d内完成挂膜启动。与立式相比，其运行所需营养液喷淋量减少，为3L·h^-1，能够达到的最佳停留时间为20s。生物滴滤床的最佳体积去除负荷提高到171g·（m³·h）^-1，最高体积去除负荷为216g·（m³·h）^-1。生物滴滤床压降在整个实验周期内保持在200Pa以内，没有出现生物膜阻塞的问题。以生物强化的方法将细菌和真菌挂膜到立式生物滴滤塔进行闲置后的再启动研究。生物滴滤塔中的土著微生物和接种微生物能够共存，对H₂S降解率能够达到85%以上。立式生物滴滤塔的最佳去除负荷由最初的110g·（m³·h）^-1提高到129g·（m³·h）^-1，最大去除负荷由最初的152g·（m³·h）^-1提高到170g·（m³·h）^-1。对生物强化后的立式生物滴滤塔进行了饥饿实验，生物滴滤塔净化性能能够快速恢复。采用SEM对恢复前后陶粒表面的微生物进行对比分析，菌落结构没有明显的改变。富集培养稳定运行的生物滴滤塔中填料表面的生物膜，进行了微生物的固定化研究。以机械强度和溶胀率为评价参数，确定以活性炭作为固定化实验添加剂。通过正交试验，确定影响固定化的条件因素主次顺序为：菌量＞海藻酸钠浓度＞添加剂含量＞氯化钙浓度。微生物固定化小球的最佳制备参数为：海藻酸钠浓度5%，氯化钙2.5%，活性炭含量0.3%，固定化时间12h。制备的固定化小球平均溶胀率为8.61%，培养12h后培养液浊度增加值为0.236，性能稳定。对制备的固定化活性炭小球进行了生长条件测试，最佳S^2-浓度45⁵0mg·L^-1，最佳pH值6，最适生长温度25-30℃，最佳摇床转速为120r·min-1。将活性炭固定化小球装填与生物滴滤塔进行了H₂S降解性能的实验研究，其能够实现对H₂S生物降解的快速响应，启动初期净化效率达到90%，并保持稳定。在进口浓度50²00mg·m^-3范围时，最佳停留时间为11s，净化效率能够维持在80%⁹5%之间。采用PCR-DGGE技术分析了两个生物反应器在稳定运行阶段各自的微生态结构。两个生物反应器中共有6条DGGE条带，但两个反应器中也存在各自特有的种属。立式生物滴滤塔对应的多样性指数为2.12±0.08，分期布液式生物滴滤床对应的多样性指数为2.85±0.13。分期布液式生物滴滤塔的微生物多样性优于立式生物滴滤塔。在上述实验的基础上，以米-门方程、Monod方程和质量守恒为基础，建立了微观和宏观尺度上数学模型。修正后的数学模型与实验数据具有较好的拟合性。更多还原

【Abstract】 Two different types of trickling filters were adopted to investigate H₂S removalperformances by biological method. The vertical bio-trickling filter after starvationoperation could be re-started with bioaugmentation method. The optimaltechnological condition and H₂S removal performance of immobilized beads havebeen conducted by adopting the dominant microfloras in the bio-trickling filter asbacteria source. Micro eco-structures in bio-trickling filters were tested using PCR-DGGE technology. Biodegradation dynamic model, which considered the cumulativeeffect of H₂S in bio-trickling filter, has been constructed and verified.The overall start up period of the traditional vertical bio-trickling filter was only3days by adopting the “stimulate biofilm growth by high concentration of nutrientsand improve degradation ability by competition” method. The vertical bio-tricklingfilter could achieve high removal efficiency more than90%when the empty bedresident time was longer than15s, the optimal trickling rate was6L·h^-1. In theprocess of elimination capacity test, the best volumetric elimination capacity was89.15g·（m³·h）^-1, and the maximum value was135g·（m³·h）^-1.Running parameters of grading bio-trickling filter in which gas and liquid werecontacted with a cross flow pattern. The immobilization period was still3days.Compared with the vertical one, the liquid trickling amount was lower, about3L·h^-1.Elimination capacity of grading bio-trickling filter has been improved. The bestelimination capacity was171g·（m³·h）^-1, and the maximum value was216g·（m³·h）^-1.Pressure loss was not more than200Pa in the whole experimental period.The application of bioaugmentation to re-start up the vertical bio-trickling filterafter it was shut down for some days was conducted. Results showed that significantremoval performance was achieved: indigenous microorganisms and immobilizedmicroorganisms could exist in the same reactor; the removal efficiency was more than85%at starting stage. The best elimination capacity was improved from110g·（m³·h）^-1to129g·（m³·h）^-1, while the maximum elimination capacity increased up to170g·（m³·h）^-1. Biofilm structures have not been changed when the ceramic pellets wereobserved by SEM.In the microorganisms’ immobilization test, active carbon was chosen as additiveto improve immobilized beads’ intensity. The sequences of factors influencingoptimum medium for immobilized beads production was obtained according toorthogonal experiments and the result was: microbe amount> sodium alginate>additive amount>CaCl₂. The optimal preparation parameters was sodium alginate5%,CaCl₂2.5%, active carbon0.3%, and immobilized time12h. The optimal growth conditions of immobilized beads was S^2-concentration45⁵0mg·L^-1, pH6, optimaltemperature5-30℃, rotation speed120r·min-1. Bio-trickling filter packed withimmobilized beads coud start up quickly, with removal efficiency more than90%.The optimal empty bed resident time was11s at inlet H₂S concentration rangebetween50²00mg·m³.Micro eco-structures in two bio-trickling filters were compared by PCR-DGGEtechnology. There were6same DGGE bands in the two reactors. The coexistencemicrobial species had different dominant position in their respective ecosystem. TheShannon-Weaver index of the vertical bio-trickling filter was2.12±0.08. That of thegrading bio-trickling filter was2.85±0.13. Microbial diversity of grading bio-trickling filter was higher than the vertical one.On the basis of the above data, biodegradation dynamic model was established,which considered the cumulative effect of H₂S in bio-trickling filter. The microscopicmodel could predict H₂S concentration in the biofilm. For the biodegradation processwas controlled by biochemical reaction, macroscopic model was established on thebasis of Michaelis-Menten equation. The model had a good relevance withexperimental data after modified.更多还原