运行时长和淹没高度对雨水生物滞留系统氮素去除的影响  

The Effects of Operating Time and Submerged Height on the Removal of Nitrogen in Stormwater Bioretention System

作　　者：赵凡 王洪浩 李京玲[1] 贾亚敏[1] ZHAO Fan;WANG Hong-hao;LI Jing-ling;JIA Ya-min(College of Water Resources Science and Engineering,Taiyuan University of Technology,Taiyuan 030024,China)

机构地区：[1]太原理工大学水利科学与工程学院,太原030024

出　　处：《节水灌溉》2022年第4期16-20,26,共6页Water Saving Irrigation

基　　金：山西省面上自然基金项目(201901D111059);国家自然科学青年基金项目(51409184);山西省青年科技研究基金项目(201601D202070)。

摘　　要：为提高雨水生物滞留系统对氮素的去除率,通过室内土柱(高1000 mm,直径200 mm的有机玻璃柱,出水管向上抬升用以形成不同淹没高度)物理模型试验,研究了雨水生物滞留系统运行时长(6、12、18、24、30d)及不同淹没高度(0、250、500 mm)的氮素去除效果。结果表明,30 d内,系统的渗透性能随运行时长增加而增加,渗透系数从0.44 mm/min增加到了0.98 mm/min;系统填料中的黏粒(<0.002 mm)含量随时长增加向下迁移并富集在填料中部(250 mm);NH_(4)^(+)-N去除率随运行时长增加变化较小,平均去除率为93.60%,NO_(3)^(-)-N和TN去除率随运行时长增加先增加后趋于稳定,最大去除率分别为54.45%和71.01%,COD的去除率随运行时长增加先减小后趋于稳定,变化范围为59.56%~73.85%;淹没区对NH_(4)^(+)-N的去除率影响较小,而对NO_(3)^(-)-N、TN和COD的去除率出现不同程度的增加,TN、NO_(3)^(-)-N和COD的最大去除率对应的淹没高度分别为250、500、250 mm。系统在30 d的运行时长内氮素的去除率较为稳定,并未随运行时长的增加而下降;增设淹没区能提高NO_(3)^(-)-N、TN和COD去除效率。综合考虑雨水生物系统对氮素的去除,推荐最佳淹没高度为250 mm。In order to improve the nitrogen removal efficiency of stormwater bioretention system,physical model tests of soil column(1000mm high,200 mm diameter plexiglass column,outlet pipe raised upward to form different submerged heights)were carried out to study the nitrogen removal efficiency of stormwater bioretention system under different operating periods(6 d,12 d,18 d,24 d,30 d)and differen submergence heights(0 mm,250 mm,500 mm).The results showed that within 30 days,the permeability of the system increased with the increase of operating time,the permeability coefficient increased from 0.44 mm/min to 0.98 mm/min,and the clay particles in the system filler(<0.002 mm)migrated downward and enriched in the middle of the packing(250 mm).The removal of NH_(4)^(+)-N changed little with the increase of operating time and the average removal rate was 93.60%,and the removal rates of NO_(3)^(-)-N and TN increased first and then stabilized with the increase of operating time and the maximum removal rates were 54.45%and 71.01%,respectively.The removal rate of COD decreased firstly and then stabilized with the increase of operating time,the range of change was 59.56%~73.85%.The submerged zone had little effect on the removal rate of NH_(4)^(+)-N,while the removal rates of NO_(3)^(-)-N,TN and COD increased in different degrees,and the submerged heights corresponding to the maximum removal rates of TN,NO_(3)^(-)-N,and COD were 250 mm,500 mm and 250 mm,respectively.The nitrogen removal rate was relatively stable during the 30 d operation,and not decreased with the increase of the operation time.Setting submerged zone improved the removal efficiency of NO_(3)^(-)-N,TN and COD.Comprehensively considering pollutants removal,the optimum submerged height is recommended as 250 mm.

关 键 词：雨水生物滞留系统 氮素去除 运行时长 淹没高度 

分 类 号：S27[农业科学—农业水土工程] X703[农业科学—农业工程]