【作者】 周爱姣；

【导师】 沈蕴芬； 陶涛；

【作者基本信息】 华中科技大学 ， 市政工程， 2008， 博士

【摘要】 开发高效低耗、投资省的先进的污水处理工艺技术，对防治水污染，缓解水危机具有重要的现实意义，是水处理永恒的主题。随着新型材料的开发和配套技术的不断完善，与活性污泥法同时出现的生物膜法工艺得到快速发展。作为生物膜法典型工艺的曝气生物滤池在污水的有机物去除、固液分离、硝化脱氮等方面有着良好的功效，应用范围不断扩大，由最初用于城市污水的高级处理，扩展到用作城市污水的二级处理、工业废水的处理、以及给水处理工艺中的预处理。曝气生物滤池的填料开发是其工艺发展的核心。目前应用较广泛的轻质陶粒填料克服了传统填料的诸多缺陷，但开发新的填料仍然是生物滤池处理技术广泛应用的一个重要方面，通过采用新型吸附型填料，可以大大强化曝气生物滤池对氮、磷和某些微量污染物的去除能力，从而在污水的高级处理和给水处理中发挥更大的作用。具有发达孔隙结构、巨大的比表面积和优良的吸附性能的活性炭，在水处理领域是最受青睐的一种填料，但活性炭价格高，限制了其更大范围的应用。研究替代活性炭的廉价材料仍然是目前的热点。相比之下，木炭价格较低，近年来受到人们的很大关注。本研究的协作单位在引进国外技术的基础上，开发了改性木炭污水处理及深度净化技术，这种技术在生活污水处理、湖泊水体修复、河流水生态环境保护等领域应用效果良好，处理出水水质可达到GB 3838-2002《地表水环境质量标准》Ⅳ类标准。但该技术结构单元多，有待于进一步的优化，应用于城市污水处理时存在诸多局限性；其除磷脱氮材料进口，费用较高；采用改性木炭对我国的污水水质是否必要还有待于进一步研究。本文结合曝气生物滤池和改性木炭技术的优点，将木炭这一轻质材料作为曝气生物滤池的填料，并以改性木炭和陶粒作对比，采用三套动态小试装置，研究其处理城市污水的效能和特性，主要研究内容为：研究木炭生物滤池工艺的快速稳定的启动方式；探讨反应器对COD、SS、NH₄⁺-N、TN、TP等的去除规律及pH值、曝气强度、负荷、水温等对去除效果的影响，研究反应器的最佳工艺运行参数；采用扫描电镜和显微镜等微观手段，研究木炭曝气生物滤池的填料结构、生物膜结构及生物相构成；研究木炭曝气生物滤池对微量有机物的去除效能；研究木炭生物滤池的底物降解动力学，探求动力学参数，探讨木炭脱氮机理。研究结果表明，将木炭曝气生物滤池用于城市污水的处理有效可行，具体表现在以下几个方面：（1）采用闷曝接种挂膜有助于提高木炭生物滤池初始污染物的去除率，提高溶解氧的浓度有利于缩短生物膜的挂膜时间。在挂膜初始阶段，三种填料对氨氮有一定的吸附能力。壳聚糖改性的木炭填料不利于自养型的硝化菌的生长而影响氨氮的去除，木炭的表面性质和多孔结构更加有利于硝化菌的生长而使其效果明显好于陶粒填料。（2）在水力负荷、溶解氧浓度、氨氮浓度和水温变化时，木炭滤池的除磷脱氮效果总体上优于陶粒滤池。在一定的填料高度下，木炭滤池的最佳水力停留时间为6h，DO浓度为2～3 mg／L，反冲洗周期为2～3 d。（3）环境扫描电镜和显微镜观察表明，木炭填料滤池的生物相丰富，木炭的空隙结构较陶粒更有利于原生动物、轮虫、线虫等动物的生长繁殖。（4）通过GC-MS检测，木炭生物滤池对水中残留的微量有机物去除的效果较好，优于陶粒，为木炭生物滤池在污水处理厂尾水深度处理方面提供了依据。（5）对木炭曝气生物滤池的底物去除动力学进行了研究，提出了基于Monod方程的半经验公式，即（?），公式考虑温度及有机负荷对反应速率常数的影响，主要针对COD和NH₄⁺-N的进出水浓度随反应器填料高度的变化情况而确立。公式能较好地拟合底物的降解过程，可适用于工程设计计算和运行控制。更多还原

【Abstract】 To prevent water pollution and alleviate water crisis, the development of advanced wastewater treatment processes with high effective, low consumption and investment saving, will have the vital practical significance to the districts which need pollution treatment urgently in a long time. Meanwhile, it is an eternal subject in water treatment. With the development of new material and improvement of the matched technology, biofilm method which is simultaneously invented with active sludge method obtains the fast development. As a typical process of biofilm method, the biological aerated filter （BAF） takes a good function in carbonaceous removal, liquid-solid separation and nitrification, expanding its application scope. It was firstly used as an advanced treatment in the urban sewage, and then served as the urban sewage second-level process, industrial wastewater process, as well as tap water pretreatment process.The development of the stuffing in the BAF is its core technology. At present, although wide - used light - weight haydite stuffing overcomes many shortcomings of traditional padding, development of new kinds of stuffings is still an important aspect of BAF in the application of BAF. By using new kinds of adsorptive stuffing, the removals of nitrogen, phosphorous and natural organic matters might be greatly strengthened by BAFs. And BAFs will take a more effective function in advanced treatment of sewage and tap water treatment. The activated carbon has great pore structure, huge specific surface area and perfect adsorption characteristics, which is regarded as one kind of most popular stuffing in the water treatment. But the high price restricts its wide application. Finding inexpensive material substitution for activated carbon is still a hot topic at present. Contrastly, the price of charcoal is low. Charcoal has attractived people’s much attention in recent years. This research’s cooperation company, based on the introduction of overseas technology, has developed a biological contact oxidation process called modified charcoal sewage treatment and the advanced purification technology, which gets some good effects in the treatment of domestic sewage, remediation of lake water, protection of river environmental and so on. The quality of effluent water is up to level IV specified in the Surface water Environment quality Standard GB 3838-2002. However, some problems are significant, for example: fussy structural units in this technology need to be optimized, some limitations need to be improved when used to treat urban sewage, the imported phosphorus and nitrogen removal material is costly, additionally, whether the modified charcoal is suitable to our country’s sewage quality also needs to be further studied.In this paper, combining the merits of BAF and modified charcoal process, charcoal was applied as a light - weight stuffing of biological filter to treat municipal sewage. The performance of three lab-scale biological filters was monitored to compare the characteristics and effect of charcoal with that of haydite and modified charcoal as stuffing. The main content of the study is: research on fast stable startup mode of charcoal biofilter; discussion the removal rules of COD、SS、NH₄⁺-N、TN and TP, the influence of pH value, aeration intensity, loading rate and temperature on removal efficiency, optimizing the running parameters; adoptting scanning electron microscope （SEM） and the microscope observation to study structure of stuffing and biofilm, biofacies constitution; removal efficiency of natural organic matters by charcoal biofilter, and research the substrate removal kinetics of reactors, evaluation of dynamic parameters, and discussion the mechanism of denitrogen removal.The research indicated that it was efficient and feasible to treat wastewater by charcoal biological aerated filter. It can be proved as following.（1） Inoculated biofilm formation with merely aeration was benefit for initial removal efficiency of pollutants. Increasing the dissolved oxygen （DO） concentration can shorten the total time of biofilm formation. In the initial time of biofilm formation, three kinds of stuffing can adsorb ammonia nitrogen （NH₄⁺-N） . The chitason modified charcoal stuffing was not adaptive to growth of autotroph nitrobacteria, which effect the NH₄⁺-N removal. Charcoal’s surface characteristic and pore structure was more adaptive to growth of autotroph nitrobacteria than that of haydite, and so the effect of charcoal filter was better than that of haydite.（2） By changing some parameters, such as the hydraulic loading, DO concentration, NH₄⁺-N concentration and temperature, we investigated the removal of phosphorous and nitrogen. The removal performance of the charcoal biological filter was superior to that by haydite. Under the condition of certain stuffing height, the optimum parameters by charcoal biological filter were: hydraulic retention time 6 h, DO concentration 2-3 mg/L and the backwashing period 2-3 d.（3） The scanning electron microscope （SEM） and the microscope observation indicated that various types of organism existed on the surface of charcoal. The pore structure of charcoal was more benefit to the protozoon, rotifer and nematode’s growth and reproduction than those on haydite.（4） The GC-MS examination indicated that the more efficient removal of natural organic matters by the charcoal than that by the haydite. It provided that the charcoal biofilter was an advanced technology for the treatment of tailwater from sewage treatment plant.（5） The substrates removal kinetics of reactors has been studied. On the basis of Monod equation, the half experiential formula of the reactor was established, viz.ln（S/S_i） = -1.024^（T-15） k^*A/（QS_i）ⁿH. The influence of temperature and the organic loadingon reactor velocity constant was taken into account. It showed the concentration of COD and NH₄⁺-N, which changed with the height of stuffing. The formula can model the degradation process of substrate and can be used in engineering design and running control.更多还原