水平潜流人工湿地在不同水力负荷下的水力效率及可视化分析

构建水平潜流人工湿地装置，通过NaCl示踪脉冲实验，得到不同水力负荷条件下的水力停留时间分布密度曲线，根据不同停留时间的关系计算相对水力效率，并利用染料，进行不同水力负荷下的可视化示踪实验，通过MATLAB处理得到高对比度的流态图像。观察“死区”分布，计算“死区”相对面积用以表征其水力效率。结果表明，湿地装置进水水力负荷较高或较低时，水力效率均较低，且水力负荷较大时更明显；水力分布散度（σ2θ）的大小会对水平潜流人工湿地水力效率造成较大影响；在不同水力负荷下，采用水力学效能（λ）所得到的排序结果相比短路值（s）和有效体积比（e）更能代表实际水平潜流人工湿地的水力效率。

Hydraulic efficiency of horizontal subsurface flow constructed wetlands for different hydraulic loading rates

Through conducting NaCl tracer tests,different hydraulic residence time distribution density curves for different loading rates in horizontal subsurface flow constructed wetlands were obtained.Then,hydraulic efficiencies of constructed wetlands for different loading rates were calculated.Meanwhile,visualization tests of different loading rates were performed by using dye tracer test.High contrast ratio images were processed using Matlab software for the extraction of dead zones distribution.Areas of dead zones were used to characterize hydraulic efficiency.Results showed that hydraulic efficiencies were low when hydraulic loading rates were extreme high or low.Hydraulic distribution divergence values had great impacts on hydraulic efficiency.Compared with effective volume ratio,hydraulic efficiencies were more representative for horizontal subsurface flow constructed wetlands design in reality.