基于偶联式人工湿地的城镇污水厂尾水同步脱氮除磷研究

发布时间：2018-02-24 09:44

  本文关键词： 人工湿地 城镇污水厂尾水 脱氮除磷　出处：《郑州大学》2017年硕士论文　论文类型：学位论文

【摘要】：本研究采用偶联式人工湿地处理城镇污水厂尾水,提高人工湿地内部组成环境,形成高效互利的脱氮除磷系统。偶联式湿地由垂直潜流—水平潜流组成,试验选用羊肝石、砾石、砂砾作为基质填料,芦苇、茭白、菖蒲为试验植物。实验进行了48 h静态吸附实验,对氮、磷在基质中的吸附效果进行分析。利用三种常用的吸附动力学模型对静态吸附试验结果进行分析。本试验主要从两方面研究偶联式人工湿地处理污水厂尾水的效果:(1)分析氨氮、TN、TP、COD等主要污染物的去除率;(2)在温度和pH变化时,污染物的去除率所受到的影响,确定人工湿地的最佳控制条件。通过上述方法,试验得出以下结论:(1)基质经过48h的静态吸附试验,分为四组:羊肝石、砂砾、砾石、按一定配比各组,TP去除率分别为25.17%、68.88%、52.35%、61.56%,TN去除率分别为17.26%、31.07%、23.11%、26.80%。砂砾组对磷和氮的吸附作用效果强于羊肝石和砾石,按一定配比组,中和了砂砾与砾石的优点,脱氮除磷效果相比较好,同时与砂砾组相比,更加稳定。(2)选用3种吸附动力学模型对TN、TP去除效果进行拟合。根据相关系数,TP均达到显著水平,可以判断出磷的吸附过程中,存在影响因子反应速率、扩散因子等因素。TN的相关系数值较小,显著性水平均较低,结合人工湿地中氮的去除原理,主要通过微生物作用去除,基质的吸附作用脱氮的比率很低,静态吸附试验结果说明在TN的去除过程中,基质吸附去除作用进行脱氮的比重较小。(3)经人工湿地处理后的出水中各污染物浓度为COD 5~12 mg/L、氨氮0.1~0.5 mg/L、TN 7.5~20 mg/L、TP 0.3~0.7 mg/L,出水各污染物平均值为COD 8mg/L、氨氮0.3 mg/L、TN 11 mg/L、TP 0.54 mg/L。除TP基本可以达到一级A标准外,其他指标均可稳定达到一级A标准。(4)温度变化对人工湿地中各污染物去除率有一定影响,呈现正相关关系,各个污染物最适处理温度为:COD 15~25℃,氨氮17~22℃,TN 20~25℃,TP17~22℃;pH变化对脱氮除磷影响分析,氨氮、TN去除率与pH呈负相关,规律较明显,pH先降低后增高,氨氮、TN去除率呈现先增高后降低。TP去除率整体呈现与pH值正相关,特别是9~10月,pH值出现拐点处,TP去除率出现同样拐点,但规律并不明显。
[Abstract]:In this study, the coupling constructed wetland was used to treat the tail water of the municipal wastewater treatment plant, to improve the internal composition environment of the constructed wetland and to form a highly efficient and mutually beneficial nitrogen and phosphorus removal system. The coupling wetland was composed of vertical subsurface flow and horizontal subsurface flow, and the sheep liver stone was selected in the experiment. Gravel, sand gravel as substrate filler, Reed, Zizania latifolia and Acorus calamus as experimental plants. The adsorption effect of phosphorus in substrate was analyzed. The results of static adsorption test were analyzed by using three kinds of commonly used adsorption kinetic models. The effect of coupling constructed wetland on the tail water of sewage treatment plant was studied from two aspects. The removal rate of the main pollutants, such as ammonia nitrogen, TNN, TPN, COD and so on, was analyzed when the temperature and pH changed. The influence of the removal rate of pollutants and the determination of the optimal control conditions of the constructed wetland. Through the above method, the following conclusions can be drawn: 1) the matrix is divided into four groups after 48 h static adsorption test: sheep liver stone, sand gravel, gravel, and gravel. The removal rates of TP in each group were 25.17 and 68.88, respectively, and the removal rates of TN were 17.26267.31.07and 23.110.26.80.The adsorption effect of sand gravel group on phosphorus and nitrogen was stronger than that of sheep liver stone and gravel. According to a certain ratio, the advantages of sand gravel and gravel were neutralized, and the effect of nitrogen and phosphorus removal was better than that of sand gravel. At the same time, compared with grit group, it is more stable. 2) three kinds of adsorption kinetic models are used to fit the removal efficiency of TNT TP. According to the significant level of correlation coefficient of TP, it can be determined that the reaction rate of influencing factors exists in the process of phosphorus adsorption. The correlation coefficient of diffusion factor, TN and other factors were smaller, and the significant level was lower. Combined with the principle of nitrogen removal in constructed wetland, the removal rate of nitrogen was very low by the removal of nitrogen by microorganism, and the ratio of nitrogen removal by substrate adsorption was very low. The static adsorption test results show that in the process of TN removal, The concentration of pollutants in effluent treated by artificial wetland was COD 5g / L, ammonia nitrogen 0.1 mg / L 0.5 mg / L, ammonia nitrogen 0.1 mg / L 0.5 mg / L, 20 mg / L TP 0.30.7 mg / L, the average value of each pollutant in effluent was COD 8 mg / L, ammonia nitrogen 0.3 mg / L, ammonia nitrogen 0.3 mg / LTN 11 mg / L, TP 0.54 mg / L. Basically up to the A-level A standard, The other indexes can reach the first class A standard.) the change of temperature has a certain influence on the removal rate of pollutants in constructed wetland, showing a positive correlation. The optimum treatment temperature of each pollutant is 25 鈩，

本文编号：1529788