【作者】 李柏林；

【导师】 李晔；

【作者基本信息】 武汉理工大学 ， 环境工程， 2007， 硕士

【摘要】 曝气生物滤池是符合我国国情的简易高效低耗城市污水处理新工艺，近十几年来发展迅速，将成为解决我国所面临的严峻的水环境污染和水资源短缺问题的主要技术途径之一。然而，目前曝气生物滤池在诸如填料的作用，曝气方式、处理机理、反冲洗、运行参数和进水条件控制等方面的系统研究尚不够完善，存在一系列问题。本文采用人工模拟生活污水为处理对象，通过实验室模型研究了曝气生物滤池的挂膜启动、处理效果以及生物膜特征，并通过研究环境条件对曝气生物滤池处理性能的影响，获得了曝气生物滤池的最佳运行参数，同时重点对曝气生物滤池中所采用的填料——稻壳对污染物的去除效果及去除机理进行了较为深入的分析研究。通过实验结果分析，得出以下研究结论：（1）曝气生物滤池采用“浸泡填料、闷曝再连续进水培养”的挂膜启动方式，9天可以完成挂膜过程，CODcr、NH₃-N去除率分别稳定在85％、75％左右，反应器运行稳定。（2）长期运行实验结果表明，曝气生物滤池对CODcr、NH₃-N和TP等具有较好的去除效果，平均去除率分别达到88.4％、63.9％和45.7％。（3）曝气生物滤池在三种水力负荷条件下的反冲洗周期分别为30h、28h和22h。曝气生物滤池采用气洗＋气水联合冲洗＋水漂洗的反冲洗方式可以取得良好的冲洗效果，气水强度分别为6.5～7.5L／（m²·S）和1～2L／（m²·S）。（4）微生物镜检实验结果表明，曝气生物滤池内的生物种群有明显的空间分布规律，不同高度填料层形成不同的优势菌群。曝气生物滤池沿水流方向生物膜中的优势原生动物依次为鞭毛类、游泳型纤毛类、固着型纤毛类，显示出反应器明显的推流特征。（5）在曝气生物滤池的影响因素实验中，发现水力负荷的增加对反应器的CODcr去除率影响小，但对NH₃-N和TP的去除效果有负面影响。气水比为20∶1时，不仅可提高污水的有机物和氨氮的去除效果，电可达到较好的除磷效果。曝气工况对反应器的处理效能影响较大，曝气生物滤池若想维持对CODcr、NH₃-N和TP较高的去除率，采用曝气1h停曝1h的方式是一种合理的选择。随着有机负荷的增加，NH₃-N的去除呈逐渐减小的趋势，氨氮负荷在0.06～0.45kg NH₃-N／（m³·d）之间变化时，反应器的硝化能力随氨氮负荷的增加而下降。对于本实验所采用的75cm填料高度上向流曝气生物滤池，降解CODcr的最佳填料层为0～45cm段，NH₃-N去除的最佳填料层为0～30cm段，TP在0～45cm段即可获得较高的去除率。（6）根据影响因素实验结果，确定曝气生物滤池以去除CODcr、NH₃-N和TP为目的的最佳运行参数为：流量2.7 L／h、水力负荷0.28m³／m²·h、气水比20∶1、曝气工况为曝气1h停止1h、有机负荷≤1.82 kg／（m³·d）、氨氮负荷≤0.15kg／（m³·d）、进水TP浓度≤1.7 mg／L。（7）对曝气生物滤池中污染物去除机理进行了探讨。重点对稻壳用作曝气生物滤池填料的可行性进行了分析，并通过实验加以验证，实验结果表明，稻壳填料曝气生物滤池处理生活污水是可行的。更多还原

【Abstract】 The Biological Aerated Filter （BAF） is a simple, high-efficient; low-consumptive for municipal sewage treatment corresponds to the situation of china developed rapidly in last ten years will be one of the important technical approaches to solve the water pollution and shortage problem faced china. However, there still some problems that need further study in BAF with respect to media function, aeration mode, treatment mechanisms, operational factors, backwashing and influent control, factors、backwashing and influent control. A bench scale experimental study was carried out with synthetic domestic wastewater as the model water, focusing on the start-up of reactor, treating efficiency and biofilm characteristic. The optimization operational parameters are determined by studying the environmental condition to influence the removal efficiency of pollutants; but also a depth studying was carried out by focusing on the treating efficiency and treatment mechanisms of the rice hull which was using in the BAF as filter material. It can be drawn the following conclusion derived from the experiment results.（1） It take about 9 days to succeed in cultivating biofilm using of the method of continuous flow following with soaking rice hull and intermission cultivating, when the removal rates of CODcr and NH₃-N gets to 85% and 75% and the reactor run stable.（2） The experimental results showed that the removal rate of CODcr, NH₃-N and TP in BAF system comes up to 88.4%, 63.9% and 45.7% respectively.（3） Under different conditions of three hydraulic loading, the backwash interval of BAF was 30h, 28h and 22h respectively. The backwash regimes of gas combined with water has a good backwash effect. The backwash intensity of gas and water was 6.5～7.5L/（m²·S） and 1～2L/（m²·S） respectively.（4） The microscopy results show that as microbe species in BAF distributed spatiotemporally, dominant bacteria for different height of filter material was distinctive. Along the fluent direction the superiority protozoa in biomembrane are the flagellates, the free swimming ciliate, and the sessile ciliate in turn, demonstrating the obvious plug flow characteristic.（5） Through testing the factors on BAF performance, it is found that the removal efficiency of CODcr changed little with enhancement of hydraulic loading, which whereas had the negative effect on removal efficiency of NH₃-N and TP. When the ratio of air to water was 10:1, the removal efficiency of organic pollutants, NH₃-N and TP could both be improved. The operating mode of aeration has evident influence to the removal rate in BAF system. The reactor could maintain better removal efficiency of CODcr, NH₃-N and TP, if the operating mode keeping with aeration lasts 1 hour and anoxic lasts 1 hour. With the CODcr volume loading higher, the removal of NH₃-N has a gradual lower. When NH₃-N volume loading from 0.06 kg/ （m³·d） to 0.45kg / （m³·d）, the nitration ability of reactor will be weakened gradually with the increase of NH₃-N volume loading. To the BAF in which 75cm height filter bed is used the optimal region of CODcr removal is 0～45cm, the optimal region of NH₃-N removal is 0～30cm, at 45cm height, the TP will be removed mostly.（6） According to the results of influencing factor experiment, the optimization operational parameters as follows: operation flow is 2.7 L/h, hydraulic loading is 0.28m³/m²·h, gas-water ratio is 20:1, the operating mode is aeration lasts 1 hour and anoxic lasts 1 hour, the CODcr volume loading is above 1.82 kg/（m³·d）, the NH₃-N volume loading is above 0.15 kg/（m³·d）, the concentration of TP is above 1.7 mg/L. On these conditions, the reactor had a better removal effect to CODcr, NH₃-N and TP.（7） The removal mechanisms of CODcr, NH₃-N and TP were discussed. Through the results of feasibility analysis and proving experiment with rice hull BAF, we can conclude that the rice hull BAF was a feasible reactor on treating domestic wastewater.更多还原