复合浮桥式人工湿地处理小城镇生活污水实验研究

发布时间：2018-03-05 07:29

本文选题：人工湿地　切入点：浮桥技术　出处：《西南科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：本课题实验在了解人工湿地文献资料和现有研究成果的基础上,对传统人工湿地技术进行改进,通过引进浮桥技术,在同一湿地单元中采用浮游植物搭配沉水植物联合对污水进行处理,并与两级传统下行潜流式湿地单元进行组合,设计出一组复合型人工湿地处理系统,研究该系统对生活污水中COD、NH3-N、TN、TP的净化效果。研究结果表明:(1)在整个实验运行期内,系统COD进水浓度在125.7~186.1mg/L之间,出水浓度在21.3~41.7mg/L之间,去除率维持在71.0%~83.7%;NH3-N进水浓度在21.2~26.2mg/L之间,出水浓度在6.1~10.2mg/L之间,去除率维持在53.9~71.4%;TN进水浓度在26.4~31.3mg/L之间,出水浓度在9.9~15.3mg/L之间,去除率维持在44.8~63.3%;TP进水浓度在1.62~2.71mg/L之间,出水浓度在0.32~0.87mg/L之间,去除率维持在68.0~80.3%。(2)湿地系统二级浮桥平流式湿地单元对COD的去除效果较另外两级传统潜流式湿地单元差,但对NH3-N、TN和TP的去除效果突出。整个系统COD、TN出水浓度可以达到《城镇污水处理厂污染物排放标准》(GB 18918~2002)中的一级A标准,NH3-N和TP出水浓度可以达到一级B标准。(3)湿地单元内各指标去除率的Pearson相关性分析显示,系统HVF1中COD-NH3-N、COD-TN和NH3-N-TN的去除率之间存在一定的相关性;HF2中NH3-N-TN、COD-NH3-N和NH3-N-TP的去除率具有较好的相关性;HVF3中由于受进水浓度较低的影响,除TN-TP的去除率之间存在一定的线性相关外,其他各指标间不存在明显相关性。(4)湿地系统内水力学特征分析表明,各级湿地单元中污水流动过程中均存在一定的返混现象,HVF1和HVF3两级潜流式湿地单元的返混程度较小,流态也较为稳定,HF2平流式湿地单元的返混程度较为严重。系统运行后期湿地渗透系数开始呈现不均性分布,对污染物的去处效果也有所下降。
[Abstract]:On the basis of understanding the literature and existing research results of artificial wetland, this paper improves the traditional constructed wetland technology and introduces floating bridge technology. In the same wetland unit, a composite constructed wetland treatment system was designed by using the combination of phytoplankton and submerged plants, and combined with two levels of traditional downlink subsurface flow wetland unit. The results showed that the influent concentration of COD was between 125.7 mg / L and 186.1 mg / L, the effluent concentration was between 21.3N and 41.7 mg / L, and the removal rate was maintained at 71.083.7U NH3-N between 21.2mg/ L and 26.2mg/ L during the whole operating period of the experiment, and the removal rate of NH3-N was between 21.2mg / L and 26.2 mg / L, respectively, and the removal rate of NH3-N was between 21.2mg / L and 26.2mg/ L, and the removal rate of NH3-N was between 21.2mg / L and 26.2mg / L, respectively. The effluent concentration was in the range of 6.1 ~ 10.2 mg / L, the removal rate was maintained at 53.9 ~ 71.4 mg / L, the influent concentration of TN was 26.44.31. 3 mg / L, the effluent concentration was between 9.9 ~ 15.3 mg / L, the removal rate was maintained in the range of 1.622.71 mg / L, the effluent concentration was between 0.32 and 0.87 mg / L, the removal rate was maintained in the range of 44.8 ~ 10.2 mg / L, and the effluent concentration was between 0.32 and 0.87 mg / L, respectively. The removal rate of COD was maintained at 68.0% 80.3%. 2) the COD removal efficiency of the secondary floating bridge advection wetland unit in the wetland system was lower than that of the other two subsurface flow wetland units. However, the removal effect of NH3-NN and TP is outstanding. The effluent concentration of CODN in the whole system can reach the first class A standard (NH _ 3-N) and the effluent concentration of TP can be up to the first class B standard. 3) the effluent concentration of COD _ (TN) in the whole system can reach the first class A standard (GB 1891818 ~ 2002), and the effluent concentration of TP can reach the first class B standard. The Pearson correlation analysis of the removal rate of each index within the unit showed that, There is a certain correlation between the removal rate of COD-NH _ 3-N and NH3-N-TN in system HVF1. The removal efficiency of NH _ 3-N-TNN _ (COD-NH _ 3-N) and NH3-N-TP in HF2 has a good correlation. In HVF3, there is a linear correlation between the removal rate of TN-TP and the removal rate of TN-TP due to the low influent concentration. There is no obvious correlation among other indexes. (4) the analysis of hydraulic characteristics in wetland system shows that there is a certain phenomenon of backmixing in the process of sewage flow in all levels of wetland units. The degree of backmixing of HVF1 and HVF3 subsurface flow wetland units is relatively small. The backmixing degree of HF2 advection wetland unit is more serious, and the wetland permeability coefficient begins to show uneven distribution in the later stage of the system operation, and the effect on the location of pollutants is also decreased.
【学位授予单位】：西南科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X799.3

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