Nutrient removal from urban stormwater runoff by an up-flow and mixed-flow bioretention system
Nutrient removal from urban stormwater runoff by an up-flow and mixed-flow bioretention system
复制标题
通过上流和混流生物滞留系统去除城市雨水径流中的养分
DOI：
10.1007/s11356-019-05091-4
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发表时间：
2019
影响因子：
5.8
通讯作者：
孙慧超
中科院分区：
文献类型：
--
作者：
张伟;桑敏;车伍;孙慧超
生物滞留技术是城市径流污染控制中最常用的技术措施之一。然而，从城市雨水径流的生物滞留系统去除养分的效率差异显着。为了提高系统的养分去除效果，提出了一种新型的上流式和混流式生物滞留系统，并进行了径流滞留和养分去除性能的实验室研究。在以自来水为进水的淋溶实验中，浊度、化学需氧量（COD）、总氮（TN）、总磷（TP）淋溶现象明显。与常规生物滞留系统相比，采用上向流和混合流生物滞留系统对COD和TN的淋溶控制效果明显改善。在半合成径流试验中，经过淋洗试验（累计2.78倍空床体积）后，上向流和常规生物滞留工艺的COD质量去除率差异不显著（p> 0.05），而混流式生物滞留工艺的COD质量去除率比常规生物滞留工艺提高了10%。上向流和混合流生物滞留对TN的去除率明显提高，分别从常规生物滞留的17% ± 13%提高到上向流的41% ± 23%和混合流的31% ± 16%。但是，三种生物滞留柱对TP的去除量和径流量的减少量没有显著差异（p> 0.05）。上向流和混合流生物滞留都能有效提高TN的去除效果，但由于上向流和混合流生物滞留的饱和区体积基本相同，混合流生物滞留的TN去除效果并不优于上向流生物滞留.总体而言，结果表明，在这项研究中提出的混合流生物滞留可以有效地提高TN质量去除和稍微提高COD质量去除相对于传统的方法，通过增加水力停留时间和在流动路径，分别。
Bioretention is one of the most popular technical practices for urban runoff pollution control. However, the efficiency of nutrient removal from urban stormwater runoff by bioretention systems varies significantly. To improve the nutrient removal performance, innovative up-flow and mixed-flow bioretention systems were proposed in this study, and a laboratory study was conducted to investigate the runoff retention and nutrient removal performance. During the leaching experiment using tap water as the inflow, turbidity, chemical oxygen demand (COD), total nitrogen (TN), and total phosphorus (TP) leaching phenomenon was obvious. COD and TN leaching controls were obviously improved when the up-flow and mixed-flow bioretention systems were adopted comparing with the conventional bioretention. During the semi-synthetic runoff experiments, after the leaching experiments’ performance (accumulated 2.78 times of empty bed volume), there were no significant differences in COD mass removal efficiencies of conventional and up-flow bioretention processes (p> 0.05); however, the COD mass removal efficiencies of the mixed-flow bioretention processes increased by 10% when compared with conventional bioretention. The TN mass removal efficiencies of the up-flow and mixed-flow bioretention increased obviously from 17% ± 13% (conventional) to 41% ± 23% (up-flow) and 31% ± 16% (mixed-flow). However, there were no significant differences in TP mass removal or runoff reduction among the three bioretention columns (p> 0.05). Both up-flow and mixed-flow bioretention can effectively improve TN mass removal, and the mixed-flow bioretention did not show a better TN removal performance than the up-flow bioretention because these two bioretention had almost the same volume of the saturated zone. Overall, the results indicate the mixed-flow bioretention proposed in this study can effectively improve TN mass removal and slightly improve COD mass removal relative to conventional methods via increases in hydraulic retention time and in-flow paths, respectively.