CIBR活性污泥对氨氮的吸附及氮平衡研究

发布时间：2018-04-04 10:08

  本文选题：CIBR　切入点：活性污泥　出处：《华中科技大学》2015年硕士论文

【摘要】：连续流一体化生物反应器(Continued-flow Integrated Biological Reactor,CIBR)是国家十五资助项目《城市污水生物/生态处理技术与示范》的研究成果,能够同时实现脱氮除磷的效果,其中脱氮作用主要通过活性污泥的硝化和反硝化作用获得,而活性污泥作为一种絮状结构物质,除了进行硝化反硝化反应除氮外,同时也能够通过生物吸附作用去除废水中的氨氮,这部分氨氮对于反应系统中总氮的物料平衡核算不可忽视,而对于污水处理系统中活性污泥吸附氨氮的性能和机理以及氮平衡分析的研究却很少见。本文以CIBR反应系统驯化培养的活性污泥为研究对象,通过动态和静态实验研究不同阶段(好氧和缺氧)污泥的吸附性能,同时考察各种因素(p H、初始氨氮浓度、污泥浓度、温度和盐度)对吸附的影响,并通过动力学和等温模型进行拟合探究活性污泥吸附氨氮的机理,同时进行了解吸实验确定氨氮在活性污泥上的最终吸附率,最后通过对CIBR反应系统进行物料平衡核算,来确定各种氮损失途径占进水中总氮的比例,为反应系统的优化设计和运行提供一定的数据支撑。主要研究结果如下:(1)CIBR的动态研究结果显示,好氧和缺氧阶段的污泥对废水中氨氮(NH4+-N)均存在一定的吸附作用,不同阶段吸附作用有差别;而对于废水中的硝氮(NOX-N),吸附作用很不明显,可忽略。(2)静态实验的结果表明,初始氨氮浓度是好氧和缺氧污泥吸附氨氮的一个重要影响因素,污泥的吸附量随着浓度的升高而增加,分别为0.21-1.70mg/g和0.21-1.14mg/g;当初始氨氮浓度达到70mg/L时,好氧污泥的吸附量要明显高于缺氧污泥的;p H也影响着CIBR活性污泥对氨氮的吸附量,随着p H从3升到8,吸附量逐渐升高,在p H为8时达到最大值,继续增加p H时吸附量反而降低;污泥浓度也会造成吸附量发生变化,随着浓度的升高(3000-7000mg/L),好氧和缺氧污泥对氨氮的吸附量大体上呈下降趋势;而常温范围内(20-30℃),温度对污泥吸附量影响较小,当温度升高到40℃时,好氧和缺氧污泥对氨氮的吸附较难达到稳定,且吸附量要小于常温范围;盐(Na Cl)含量越高会造成污泥的吸附量减小,当盐(Na Cl)含量达到30g/L时,好氧和缺氧污泥基本不产生吸附量。(3)动力学和等温模型的拟合结果可知,CIBR活性污泥对氨氮的吸附是一个二级动力学过程,化学过程(离子交换、静电引力)是主要的影响因素,而等温线的拟合结果较接近,好氧污泥更符合Frendliuch模型,Langmuir则对缺氧污泥拟合效果更好;而解吸实验表明缺氧污泥更易解吸下来,平均解吸率约为90%,而好氧污泥相对难解吸,平均解吸率仅为60%。(4)CIBR系统的物料平衡分析结果得出,活性污泥生物吸附作用占总氮去除率约为9.56%,在物料平衡核算中不容忽视,否则将造成较大误差,而制约CIBR总氮去除率的主要因素则是系统的反硝化速率。
[Abstract]:Continuous flow integrated bioreactor Continued-flow Integrated Biological Reactorr (CIBR) is the research result of "Biological / Ecological treatment Technology and demonstration of Municipal sewage", which can simultaneously realize the effect of nitrogen and phosphorus removal.Denitrification was mainly obtained by nitrification and denitrification of activated sludge, and activated sludge, as a kind of flocculent structure substance, except nitrogen was removed by nitrification and denitrification.At the same time, the ammonia nitrogen in wastewater can be removed by biosorption. This part of ammonia nitrogen can not be ignored in the material balance accounting of total nitrogen in the reaction system.However, there are few studies on the performance and mechanism of activated sludge adsorption of ammonia nitrogen and nitrogen balance analysis in wastewater treatment system.In this paper, the activated sludge domesticated by CIBR reaction system was used as the research object. The adsorption properties of sludge at different stages (aerobic and anoxic) were studied by dynamic and static experiments. At the same time, various factors such as pH, initial ammonia nitrogen concentration and sludge concentration were investigated.The effect of temperature and salinity on the adsorption was studied by kinetic and isothermal model. The desorption experiment was carried out to determine the final adsorption rate of ammonia nitrogen on activated sludge.Finally, the material balance of CIBR reaction system is calculated to determine the proportion of nitrogen loss to the total nitrogen in the influent, which provides certain data support for the optimal design and operation of the reaction system.The main results are as follows: (1) the dynamic study of CIBR shows that the sludge at aerobic and anoxic stages has a certain adsorption effect on NH _ 4-N in wastewater, and the adsorption action is different in different stages.The results of static experiments show that the initial concentration of ammonia nitrogen is an important factor affecting the adsorption of ammonia nitrogen by aerobic and anoxic sludge.When the initial concentration of ammonia nitrogen reached 70mg/L, the adsorption capacity of aerobic sludge was significantly higher than that of anoxic sludge, which also affected the adsorption of ammonia nitrogen by CIBR activated sludge, and the adsorption capacity of aerobic sludge increased with the increase of concentration of 0.21-1.70mg/g and 0.21-1.14 mg / g, respectively, when the initial concentration of ammonia nitrogen reached 70mg/L, the adsorption capacity of aerobic sludge was significantly higher than that of anoxic sludge.With pH rising from 3 to 8, the adsorption capacity increased gradually, reached the maximum value at pH 8, and decreased with the increase of pH, and the sludge concentration also resulted in the change of adsorption capacity.With the increase of concentration of 3000-7000mg / L, the amount of ammonia nitrogen adsorbed by aerobic and anoxic sludge showed a decreasing trend in general, while in the normal temperature range of 20-30 鈩，

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