潜流人工湿地水力学特性与污染物运移实验研究及数值模拟

发布时间：2018-01-06 21:12

本文关键词：潜流人工湿地水力学特性与污染物运移实验研究及数值模拟　出处：《合肥工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：人工湿地污水处理技术作为一项处理效率高、运行维护成本低、环境友好的生态污水处理技术在我国得到了广泛的应用与关注。水平潜流人工湿地具有卫生条件好、受温度影响低、处理效率高等优点,在人工湿地工程中占有较高的比例。水力学性能与污染物运移规律对于潜流人工湿地系统的设计和运行十分重要。本研究首先利用示踪剂实验与计算流体力学的数值仿真模拟方法对水平潜流人工湿地的水力学特性进行了研究,探究出水口位置、水力停留时间、基质填料方式对潜流湿地系统水力学性能的影响,并在此基础上提出一种新型高效防堵塞人工湿地模型;其次以污水厂二沉池出水为对象,考察了湿地系统对废水组分硝酸盐氮(NO3--N)、氨氮(NH4+-N)、亚硝酸盐氮(NO2--N)和COD的去除效率,并采用自主开发的《污染物湿地修复模拟系统V1.0》对污染物迁移规律进行了模拟研究,以磷酸盐为代表对模型进行了验证。得出的主要结论如下:(1)横向基质排布湿地系统单出水口出水条件下,同湿地中出水口出水和下出水口出水相比,上出水口出水时湿地的水力学效率最高,短路值最小,水力学性能最好;(2)横向基质排布湿地系统多出水口出水条件下,同湿地上下出水口出水、中下出水口出水以及上中下出水口同时出水相比,上中出水口出水的水力学效率最高,短路值最小,水力学性能最好;(3)横向基质排布湿地系统上出水口出水条件下,水力效率随水力停留时间先增加后降低,在实验范围内的最佳水力停留时间为1天;(4)横向基质排布湿地系统对二沉池出水中硝酸盐氮(NO3--N)、氨氮(NH4+-N)的去除率可以达到90%以上,对亚硝酸盐氮(NO2--N)的去除率在50%-75%范围内波动,对COD的去除率在60%左右。而湿地系统对磷酸盐的去除随时间逐渐降低,运行结束时磷酸盐去除率降低至22%;(5)湿地系统运行过程中磷酸盐浓度变化最大的方向与湿地系统内部水流流速较快的方向较为一致,《污染物湿地修复模拟系统V1.0》对湿地系统内部的水流与污染物运移模拟结果较为准确,与实验分析结果相符。
[Abstract]:Artificial wetland sewage treatment technology is a high efficiency, low operation and maintenance cost, environmental friendly ecological wastewater treatment technology is widely used and concerned in our country. The level of wetlands have good sanitary conditions, affected by temperature and low processing efficiency, high proportion in the artificial wetland project. The hydraulic performance and pollutant migration is very important for the design and operation of subsurface flow constructed wetland system. Firstly, using numerical simulation of tracer experiments and computational fluid dynamics method to simulate the hydraulic characteristics of the horizontal subsurface flow constructed wetland was studied, explore the outlet position, hydraulic retention time, the effect of matrix filler on the hydraulic performance of subsurface flow wetland system and on this basis, a new efficient anti clogging model of artificial wetland; next to the sewage treatment plant two sedimentation tank Water as the object, the wetland system divided the nitrate nitrogen of wastewater was investigated (NO3--N) group (NH4+-N), ammonia nitrogen, nitrite nitrogen (NO2--N) removal efficiency and COD, and the independent development of the wetland restoration "pollutant simulation system V1.0> on pollutant migration was simulated by using phosphate as research, on behalf of the model verified. The main conclusions are as follows: (1) the transverse matrix arrangement of wetland system single outlet water conditions, compared with the water in the wetland water outlet and the water outlet, the water outlet hydraulic efficiency of wetland is the highest value of the minimum short-circuit, the best hydraulic performance; (2) the transverse matrix arrangement of the water outlet system of wetland under the condition of the same wetland on the water outlet, the lower water outlet and lower water outlet and water in the water outlet compared to the hydraulic efficiency is highest, the minimum value of the hydraulic circuit. The best; (3) the water outlet conditions of transverse matrix arrangement on wetland system, the hydraulic efficiency with the hydraulic retention time increased first and then decreased in the experimental range, the optimum hydraulic retention time of 1 days; (4) the transverse matrix arrangement of wetland system on two heavy tank effluent nitrate nitrogen (NO3--N), ammonia nitrogen (NH4+-N) the removal rate can reach above 90%, the nitrite nitrogen (NO2--N) removal rate in the range of 50%-75%, the removal rate of COD is about 60%. The wetland system on the removal of phosphate decreases with time, running at the end of the phosphate removal rate reduced to 22%; (5) the change of phosphate concentration operation the process of wetland and wetland system in the direction of maximum internal flow velocity fast direction is consistent, "pollutant wetland restoration simulation system V1.0> flow and pollutant transport of wetlands within the system more accurate simulation results, and experimental points The result accords with the result.

【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X703

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