【作者】 贾小宁；

【导师】 李彦锋；

【作者基本信息】 兰州大学 ， 环境科学， 2014， 博士

【摘要】 氮污染问题越来越被重视,具有低碳氮比水质特性的污水的脱氮问题更是目前众多学者关注的热点。针对低碳氮比污水的生物处理工艺存在许多局限性。研发结构简单、操作方便、处理效率高,无二次污染的脱氮工艺,以满足低碳氮比废水的脱氮要求,是环境工作者所面临的重要课题。本学位论文以固定化微生物技术为核心,从载体的选择和反应器结构的优化两个方面着手,对比了陶粒固定化微生物固定床(CIFB)和聚氨酯泡沫固定化微生物流化床(PIFB)的净化性能,构建了O/A单级生物流化床脱氮反应器(O/A-BFB),陶粒-聚氨酯泡沫层叠式组合床脱氮反应器(CL-BMB)及沸石-聚氨酯泡沫层叠式组合床脱氮反应器(ZL-BMB)三种新型固定化微生物低碳氮比污水处理工艺。从载体的材质、运行条件、净化机理、动力学模型几个方面对各工艺的净化性能进行研究,从而开发出固定化微生物组合床型处理低碳氮比污水新工艺。主要研究结果如下：1、对比了陶粒固定化微生物固定床(CIFB)和聚氨酯泡沫固定化微生物流化床(PIFB)的净化性能。研究结果表明：在相同操作条件下,PIFB对COD和NH3-N的去除率比CIFB的高,CIFB的TN去除率比PIFB的高。2、为提高PIFB的总氮去除效率,通过改变曝气方式,增加缺氧处理区,将其改造为O/A单级生物流化床脱氮反应器(O/A-BFB),研究了气水比、水力负荷、缺氧层高度、碳氮比、NH3-N负荷对COD, NH3-N和TN去除率的影响,并建立了O/A-BFB动力学模型。结果表明：在气水比为1、水力负荷为0.47m3/(m2·h)、缺氧层高度300mm的最佳工艺条件下,对于C/N为3、NH3-N初始浓度10m/L污水,O/A-BFB对COD、NH3-N和TN的去除率分别为70.24%、97.89%和72.52%;反应器的动力学模型可表示为：Se=S0e-0.0936/(1+0.6593t)。3、结合陶粒和聚氨酯泡沫两种固定化微生物载体的优点,将生物流化床与固定床有效组合,构建陶粒-聚氨酯泡沫层叠式组合床脱氮反应器(CL-BMB),研究了反应器对COD、NH3-N和TN去除效果,以及在不同填料层去除效率的变化情况,建立了CL-BMB动力学模型。结果表明：在气水比为1,水力负荷0.47m3/(m2·h), C/N为3, NH3-N初始浓度10mg/L的运行条件下,CL-BMB对COD、NH3-N和TN的去除效率分别为90.3%、99.9%和58.6%；在距离滤料底部250mmm处COD和NH3-N去除效率的增量最大,在距离滤料底部500m处TN去除效率的增量最大;COD和NH3-N的出水浓度与进水浓度和滤料高度之间的关系可以表示为：1n(Co/C)=(0.0023/Q0C0.09398)H和1n(Co/C)=(0.015/Q0C00.5641)H。4、为进一步改进CL-BMB的性能,对天然沸石改性,研究了改性沸石对氨氮的动态吸附效果,在此基础上,利用改性沸石对NH4+的吸附交换特性,构建沸石-聚氨酯泡沫层叠式组合床脱氮反应器(ZL-BMB),研究其对COD、NH3-N及TN的去除效果。结果表明：在气水比为1,水力负荷0.47m3/(m2·h), C/N为3, NH3-N初始浓度10mg/L的运行条件下,ZL-BMB对COD、NH3-N和TN的去除率分别为90.6%、99.6%和73.7%。更多还原

【Abstract】 Nitrogen pollution has been more and more attentions. The research about low carbon to nitrogen ratio sewage denitrification has become the focus of attention at home and abroad. Biological treatment processes for low carbon to nitrogen ratio sewage have a number of limitations. The important topic for environmental workers is to research and development advanced denitrification process, which is simple structure, convenient operation, high treatment efficiency and no secondary pollution, in order to increase the denitrification efficiency of low carbon to nitrogen ratio sewage.This paper compared the purification performance of ceramsite immobilized microorganism fixed bed (CIFB) with polyurethane foam immobilized microorganism fluidized bed (PIFB), Built O/A single-stage biological fluidized bed (O/A-BFB), ceramsite-polyurethane foam layered combination bed (CL-BMB) and zeolite-polyurethane foam layered combination bed (ZL-BMB) based on immobilized microorganisms technology. The performance of biological reactor was researched containing the medium selection, process design, operation conditions, kineties and mechanism to improve the total nitrogen removal efficiency. The main results are as following:1. Two kinds of carrier material, polyurethane foam and ceramsite, were loaded into biological filter to compare the efficiency of their microbial treatment of sawage. It was shown that under the same operating conditions, the reductions in the overall NH3-N and COD by the CIFB supported by macroporous polyurethane were higher than those of the PIFB supported by ceramsite. However, the efficiency of the CIFB with macroporous polyurethane in removing TN was lower than that of the PIFB with ceramsite.2. In order to improve the total nitrogen removal efficiency, it was reconstructed to Aerobic/anoxic immobilized microorganism aerated floating filter by adding anoxic treatment zone, and its treatment efficiency and kinetics was investigated. The results showed that the pollutants can be most effectively removed at air/water ratio of1, hydraulic load of0.47m3/(m2. h), anoxia layer high of300mm. When C/N ratio was maintained at3, the NH3-N initial concentration was about10mg/L, the removal efficiency of COD、NH3-N and TN was70.24%、97.89%and72.52%respectively. The general kinetic equation at experimental conditions was as follow:Se=SO e-0.0936t/(1+0.6593t). 3. Taking advantages of the two mediums, ceramsite and macroporous polyurethane foam, a layered biological aerated filter (CL-BMB) was built to treat the low carbon-to-nitrogen micro-polluted water. The CL-BMB was operated at air/water ratio of1, hydraulic load of0.47m3/(m2·h), C/N ratio of3and the NH3-N initial concentration about10mg/L, the removal efficiency for COD, NH3-N and TN was90.3%,99.9%and58.6%respectively. The greatest increment of COD and NH3-N removal efficiency happened on the bottom250mm of medium height. The greatest increment of TN removal efficiency happened on the bottom500mm of medium height. The kinetic performance of the CL-BMB indicated that the relationship of COD and NH3-N removal efficiency with the influent COD and NH3-N concentration could be described by ln(Co/C)=(0.0023/Q0C00.9398)H and ln(C0/C)=(0.015/Q0C00.5641)H.4. In order to improve the performance of the CL-BMB, ceramsite was replaced by zeolite, zeolite and polyurethane foam layered biological aerated filter (ZL-BMB) was built. The ZL-BMB was operated at air/water ratio of1, hydraulic load of0.47m3/(m2·h), C/N ratio of3and the NH3-N initial concentration about10mg/L, the removal efficiency for COD, NH3-N and TN was90.6%、99.6%and73.7%respectively.更多还原