冬季保温和组合填料提高复合生态湿地去除尾水氮磷效应的研究

发布时间：2018-11-04 15:54

【摘要】：氮磷是造成水体富营养化的主要元素,污水处理厂中的尾水需要进一步处理,以适应目前对尾水排放的新要求。人工湿地技术是一种成本低、效果好、维护简单的污水处理技术。目前对人工湿地的研究多集中在小试阶段,对大型的人工湿地工程的运行效果的研究较少。冬季去除效果较差,一直是限制人工湿地推广的一个重要因素。本文以临安污水处理厂尾水高效复合植物生态系统为研究对象,分析了大型人工湿地工程在运行前两年的污水处理效果,研究了冬季大棚保温和复合基质对人工湿地氮磷的去除效果。取得的主要研究成果如下：1.高效复合植物生态系统对污水处理厂的尾水具有良好的净化作用,对NH4+-N、NO3--N和TN的两年平均去除率分别达到了78.1%、32.7%、37.8%,对TP和COD的两年平均去除率分别为77.2%和45.6%。高效复合植物生态系统在运行的第二年,对COD和氮素的去除率达到稳定水平,而对总磷的去除率在第一年就达到了稳定。夏季湿地对各污染物去除效果最佳。2.具有大棚保护的复合植物生态系统在低温条件下仍然能够保持较高的污染物去除率,在温度较低的12月、1月和2月,系统对氨氮、硝态氮和总氮的平均去除率分别达到了68%、34%和39%,对总磷和COD的平均去除率分别达到了87%和34%。在低温季节,添加大棚能够显著提高氮、磷和COD的去除率,提高冬季系统对污染物的去除能力,保持系统全年高效的运行。3.在磷的去除方面,等温吸附实验表明：Langmuir方程能够很好的描述沸石、红页岩和钢渣对氮、磷的吸附过程。吸附动力学实验表明：一级动力学方程和二级动力学方程对沸石、红页岩和钢渣对氮、磷的吸附动力学过程描述最准确。具有沸石的组合填料对氨氮的吸附效果最好,去除率在90%以上,具有钢渣的组合填料对磷的吸附效果最好,去除率在99%以上。沸石+钢渣+红页岩的组合具有良好的脱氮除磷能力。
[Abstract]:Nitrogen and phosphorus are the main elements that lead to eutrophication of water body. The tailings in wastewater treatment plant need to be further treated in order to meet the new requirements of tailings discharge. Constructed wetland technology is a low cost, good effect, simple maintenance of sewage treatment technology. At present, the research on constructed wetland is mostly in the small trial stage, but the research on the operation effect of the large-scale constructed wetland project is less than that of the large scale constructed wetland project. The poor removal effect in winter has been an important factor limiting the popularization of constructed wetland. In this paper, the effect of sewage treatment of large constructed wetland project in two years before operation was analyzed by taking the plant ecosystem of high efficiency and high efficiency in tail water of Lin'an sewage treatment plant as the research object. The effect of greenhouse heat preservation and composite substrate on nitrogen and phosphorus removal in constructed wetland in winter was studied. The main research results are as follows: 1. The high efficiency compound plant ecosystem has good purifying effect on the tail water of the sewage treatment plant. The average removal rate of NH4-Nno 3-N and TN in two years has reached 78. 1% and 32. 7% and 37. 8%, respectively. The average removal rates of TP and COD were 77.2% and 45.6% respectively. In the second year of operation, the removal rate of COD and nitrogen reached a stable level, while the removal rate of total phosphorus reached a stable level in the first year. The summer wetland has the best effect on the removal of pollutants. 2. The compound plant ecosystem with greenhouse protection can still maintain a high pollutant removal rate at low temperature, and in December, January and February, the system has a higher removal rate of ammonia nitrogen. The average removal rates of nitrate nitrogen and total nitrogen reached 68% and 39% respectively. The average removal rates of total phosphorus and COD reached 87% and 34% respectively. In the low temperature season, the addition of greenhouse can significantly improve the removal rate of nitrogen, phosphorus and COD, improve the removal ability of pollutants in winter system, and keep the system running efficiently all year round. In the aspect of phosphorus removal, the isothermal adsorption experiments show that the Langmuir equation can well describe the adsorption process of nitrogen and phosphorus on zeolite, red shale and steel slag. The adsorption kinetics experiments show that the first order kinetic equation and the second order kinetic equation are the most accurate description of the adsorption kinetic process of zeolite, red shale and steel slag for nitrogen and phosphorus. The combined packing with zeolite has the best adsorption efficiency for ammonia nitrogen, the removal rate is more than 90%, and the combined filler with steel slag has the best adsorption effect on phosphorus, and the removal rate is above 99%. The combination of zeolite steel slag red shale has good denitrification and phosphorus removal ability.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：X703

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