Hydraulic performance of horizontal subsurface flow constructed wetlands for different strategies of filling the filter medium into the filter basin
Hydraulic performance of horizontal subsurface flow constructed wetlands for different strategies of filling the filter medium into the filter basin
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DOI：
10.1016/j.ecoleng.2006.07.017
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发表时间：
2007
影响因子：
3.8
通讯作者：
F. Suliman;C. Futsaether;U. Oxaal
中科院分区：
文献类型：
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作者：
F. Suliman;C. Futsaether;U. Oxaal
采用水平潜流人工湿地的准二维流池模型，研究了在向滤池中填充非均质过滤介质之前，将湿地划分为更小的垂直部分如何改变过滤材料的填料，从而改变流量分布。通过过滤介质的流动用黑氨酸染料可视化。利用氯化物示踪剂获得了流动池的突破曲线。研究了三种进出口配置，以评估进出口位置对流动的影响，因为进出口位置除了过滤介质的非均质性外，还可能促进优先路径和死区的发展。过滤介质的填充模式取决于截面的数量。如果在填充前未对湿地模型进行分区（一段），则滤料大致形成水平层，粗、细料分层交替。然而，增加截面数降低了层的连续性，增加了流动分布。这样可以获得更长的滞留时间和更高的水力效率系数。当断面数较少时，进出口结构对水力参数的影响较大。综上所述，将人工湿地分成若干段后再向池内注入过滤介质，可提高处理效率。
A quasi-two-dimensional flow cell model of a horizontal subsurface flow constructed wetland was used to investigate how partitioning the wetland into smaller vertical sections prior to filling a heterogeneous filter medium into the filter basin altered the filter material packing and thereby the flow distribution. The flow through the filter medium was visualized using Nigrosine dye. Breakthrough curves for the flow cell were obtained using chloride tracer. Three inlet–outlet configurations were examined to assess the effects of the inlet and outlet positions on the flow since the inlet–outlet locations in addition to the filter medium heterogeneity may promote the development of preferential paths and dead zones. The filter medium packing patterns were dependent on the number of sections. If the wetland model was not partitioned prior to filling (one section), the filter material formed roughly horizontal layers with alternate layers of coarse and fine material. However, increasing the number of sections reduced the layer continuity and increased the flow distribution. This yielded longer retention times and higher hydraulic efficiency factors. The effect of the inlet–outlet configuration on the hydraulic parameters was greater when the number of sections was small. These results suggest that dividing the constructed wetland into several sections prior to filling the filter medium into the basin will improve the treatment efficiency.