生物滞留槽对城市路面径流水质处理效果的试验研究

利用6条配置不同填料的生物滞留槽中型试验装置,通过室外试验、数理统计和数学模拟研究填料类型、填料组合方式、填料厚度、污染物特性及植被条件等因素对生物滞留槽调控效果的影响。通过不同影响因素的多水平正交试验表明:选取粉煤灰为填料、厚度为45 cm,植被为黄杨+麦冬草时滞留槽去除污染物的综合效果最优;建立了总氮、总磷去除率与各影响因素的多元回归模型,并用Hydrus-1D模型模拟了三种入流浓度下总磷在滞留槽中的迁移,模拟值与实测值的平均相对误差分别为16.51%、13.03%和23.49%,模拟结果可靠。

Experimental study on effects of bioretention tank purifying urban road runoff

Six field experimental devices have been used to study the performance of bioretention tanks with different fillers in purification of urban road runoff. Through field tests, mathematical statistics and numerical simulation, this study focused on the control effect of bioretention tanks under the influences of five major factors: filler types, filler combinations, filler thickness, pollutant characteristics, and vegetation conditions. Multi-level orthogonal tests on these factors show that the best way to remove pollutants is to select fly ash for the filler and a filter thickness of 45cm, along with the vegetation of boxwood combined with Ophiopogon japonicus. We developed multiple regression models of removal rate of the pollutants (total nitrogen and total phosphorus) versus the influencing factors. Our simulation of the migration of TP in the tanks in three inflow concentration scenarios using Hydrus-1D achieved satisfactory results of mean relative errors 16.51%, 13.03%, and 23.49% relative to the measured values.