用潮汐流人工湿地处理高速公路服务区污水的研究

发布时间：2018-08-23 20:30

【摘要】：服务区是高速公路的重要服务设施,近年来,高速公路服务区建设数量不断上升,但服务区远离市区,服务区产生的污水无法接入市政排水管网,需建设独立的排水系统和污水处理设施。服务区污水具有水质水量变化大、氨氮总磷浓度高等的特点,根据服务区污染现状及各类污水处理工艺的特点。采用“进水-淹没反应-出水-闲置’周期运行的新型潮汐流人工湿地作为处理工艺,其潮汐式的运行方式可以较大程度提高湿地复氧能力和复氧量,有利于提高微生物对有机物的好氧降解。本文设计芦苇和菖蒲床潮汐流人工湿地,通过处理效果的对比研究,确定潮汐流人工湿地最优运行方式；通过不同有机负荷和氮磷负荷的对比研究,确定研究潮汐流人工湿地的污水净化能力；通过添加重金属Zn,研究潮汐流人工湿地对重金属的去除能力。通过试验研究,可得出以下结论：(1)潮汐流人工湿地的淹没反应时间和空床闲置时间不同,湿地进出水的pH, DO以及芦苇和菖蒲床湿地对总磷、氨氮、总氮、CODcr、SS的去除效果不同,淹没反应时间为6-24h,空床闲置时间为6h、24h时可取得最佳处理效果,考虑湿地运行的工程应用实际情况和经济效益,确定淹没反应时间6h、空床闲置时间6h为最佳水力运行条件。(2)进水氨氮、总磷含量过低或过高都不利于湿地对污染物的去除,在总磷进水浓度波动范围为0.96 mg·L-1-5.71 mg·L-1时,芦苇床湿地、菖蒲床湿地对总磷的平均去除率为56.60%和51.67%：在氨氮进水浓度波动范围为11.00mg·L-1-65.45 mg·L-1时,芦苇床湿地、菖蒲床湿地对总磷的平均去除率为46.03%和48.44%,芦苇床湿地对总磷的去除效果较好，，菖蒲床湿地对氨氮的去除效果较好,进水水质波动对CODcr的去除效果有一定的影响,但两湿地系统的CODcr去除基本在80%以上。(3)芦苇和菖蒲床湿地系统对径流污水中SS、总磷的去除率可达90%、50%左右；对氨氮的去除率维持在40%-50%左右；两湿地系统对CODCr的去除率基本维持在80%-90%范围内,硝态氮、亚硝态氮在湿地系统中略有积累。进水总Zn平均浓度为1.098 mg·L-1时,芦苇床湿地对溶解态Zn、总Zn的平均去除率为52.74%和62.65%,菖蒲床湿地对溶解态Zn、总Zn的平均去除率为47.60%和59.15%,湿地对总Zn的去除效果比对溶解态Zn的去除效果好；芦苇床湿地对径流污水中各类污染物和Zn的去除能力比菖蒲床湿地更高。(4)充分利用芦苇和菖蒲湿地的各自优势,采用两级串联潮汐流人工湿地,对各类污染物的去除率均显著(P0.01)高于芦苇床或菖蒲床湿地单独处理,氨氮出水浓度基本达到城市污水再生利用标准(GB/T18920-2002), CODcr浓度达到生活杂用水水质标准(CJ/T48-1999)。湿地串联系统的各级出水污染物浓度呈阶梯状递减,且二级处理的湿地床对各污染物的去除能力比一级处理低。芦苇床-菖蒲床串联运行对总磷、氨氮和总氮的去除效果优于菖蒲床-芦苇床串联。(5)芦苇根际脲酶活性高于菖蒲,这也是芦苇床湿地对径流污水中氮去除能力比菖蒲床湿地更强的原因之一。重金属Zn对芦苇根际脲酶活性有一定的抑制作用,对菖蒲根际脲酶活性影响不大。磷酸酶活性受重金属Zn影响较大,Zn对芦苇根际磷酸酶有一定的刺激作用,对菖蒲根际磷酸酶具有一定的抑制作用。
[Abstract]:Service area is an important service facility of expressway. In recent years, the number of expressway service area has been increasing. However, the service area is far away from the urban area, and the sewage produced by service area can not be connected to the municipal drainage network. Independent drainage system and sewage treatment facilities need to be built. According to the pollution situation in the service area and the characteristics of various sewage treatment processes, a new tidal flow constructed wetland with periodic operation of inflow-submergence reaction-effluent-idle is adopted as the treatment process. Its tidal operation mode can greatly improve the wetland reoxygenation capacity and the amount of reoxygenation, which is conducive to improving the microorganism to organic matter. In this paper, a tidal flow constructed wetland with reed and calamus bed was designed to determine the optimal operation mode of tidal flow constructed wetland through the comparative study of treatment effect; the sewage purification capacity of tidal flow constructed wetland was determined by the comparative study of different organic load and nitrogen and phosphorus load; and the tidal current was studied by adding heavy metal Zn. The removal capacity of heavy metals in tidal flow constructed wetlands can be concluded as follows: (1) The submergence reaction time and idle bed time of tidal flow constructed wetlands are different, and the removal efficiency of total phosphorus, ammonia nitrogen, total nitrogen, CODcr and SS by reed and calamus bed wetlands are different. The submergence reaction time is 6-24 hours. The best treatment effect can be obtained when the idle time of the empty bed is 6h and the idle time of the empty bed is 6h and 24h. Considering the actual engineering application and economic benefit of the wetland operation, the optimal hydraulic operation conditions are determined as the submerged reaction time is 6h and the idle time of the empty bed is 6h. (2) The influent ammonia nitrogen, the low or high content of total phosphorus are not conducive to the removal of pollutants in the wetland, and the concentration of total phosphorus The average removal rates of total phosphorus were 56.60% and 51.67% in reed bed wetland and calamus bed wetland when the fluctuation range was 0.96 mg 65507 The removal efficiency of CODcr in the two wetland systems was more than 80%. (3) The removal efficiency of SS in runoff effluent by reed and calamus bed wetland systems was up to 90% and 50% respectively, and the removal efficiency of ammonia nitrogen was maintained at 40% - 5%. The average removal rates of dissolved Zn and total Zn were 52.74% and 62.65% in reed bed wetland and 52.74% and 62.65% in calamus bed wetland, respectively. The removal efficiency of total Zn by wetland was better than that by dissolved Zn (47.60% and 59.15%). The removal capacity of pollutants and Zn by reed bed wetland was higher than that of calamus bed wetland. (4) The two-stage tidal flow constructed wetland was used to remove all kinds of pollutants by making full use of the respective advantages of reed and calamus bed wetland. The effluent concentration of ammonia nitrogen reached the standard of municipal wastewater reuse (GB/T18920-2002) and the CODcr concentration reached the standard of domestic and miscellaneous water quality (CJ/T48-1999). The pollutant concentration of effluent from the series system of wetlands decreased step by step, and the secondary treatment of wetland bed pairs was also carried out. Reed bed-gladiolus bed is better than Gladiolus bed in removal of total phosphorus, ammonia nitrogen and total nitrogen. (5) Urease activity in rhizosphere of reed bed is higher than that of Gladiolus bed, which is one of the reasons why reed bed wetland has stronger nitrogen removal ability in runoff sewage than Gladiolus bed wetland. The activity of urease in rhizosphere of Reed was inhibited, but not in rhizosphere of calamus. The activity of phosphatase in rhizosphere of Reed was greatly influenced by Zn. Zn stimulated phosphatase in rhizosphere of reed and inhibited phosphatase in rhizosphere of calamus.
【学位授予单位】：中国海洋大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X734

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