Assessment of the Hydraulic and Toxic Metal Removal Capacities of Bioretention Cells After 2 to 8 Years of Service
Assessment of the Hydraulic and Toxic Metal Removal Capacities of Bioretention Cells After 2 to 8 Years of Service
复制标题
生物滞留池使用 2 至 8 年后的水力和有毒金属去除能力评估
DOI：
10.1007/s11270-013-1803-y
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
R. Hozalski
中科院分区：
文献类型：
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作者：
K. Paus;J. Morgan;J. Gulliver;T. Leiknes;R. Hozalski
生物滞留池（也称为雨水花园）越来越多地被建造为收集、渗透和处理雨水径流的一种手段。然而，人们担心雨水管理实践随着时间的推移如何在渗透和污染物清除方面发挥作用。 2006 年使用渗透计获得了 8 个单元的饱和水力传导率 (Ksat) 值，并于 2010 年再次获得了其中 3 个单元的饱和水力传导率 (Ksat) 值。观察到平均 Ksat 与服务时间呈强正相关（斜率 = 10.2±2.4 cm/h 每年，R2 = 0.67）。对从 6 个生物滞留池收集的生物滞留介质芯进行金属分析的结果显示，表面存在 Cu 和 Zn 富集的预期趋势，而仅在所分析的 72 个介质样品中的 1 个中检测到了 Cd。现场介质样品批量测试的吸附等温线（T = 22.5 °C，pH = 7.2）用于根据代表性雨水 Cd 和 Zn 浓度估计金属吸附能力。没有考虑铜，因为在这些条件下几乎没有金属溶解（22.8±7.1%）。 Cd (10.2±±3.1 mg/kg) 和 Zn (294.9±14.9 mg/kg) 的平均平衡吸附容量远远超过生物保留介质中观察到的水平，因此细胞的 Zn 剩余吸附容量≥83%，Cd ≥90%。总体而言，这项研究的结果表明，生物滞留细胞可以提供多年的有效渗透（> 6 年）和金属去除性能（> 25 年）。
Bioretention cells, also known as raingardens, are increasingly being constructed as a means to collect, infiltrate, and treat stormwater runoff. There are concerns, however, about how stormwater management practices might function in terms of infiltration and pollutant removal as they age. Saturated hydraulic conductivity (Ksat) values were obtained for eight cells in 2006 and again for three of those cells in 2010 using an infiltrometer. A strong positive correlation of mean Ksat with service time was observed (slope = 10.2 ± 2.4 cm/h per year, R2 = 0.67). Results from metals analyses of bioretention media cores collected from six bioretention cells showed the expected trend of Cu and Zn enrichment at the surface while Cd was detected only in one out of 72 media samples analyzed. Sorption isotherms from batch testing of field media samples (T = 22.5 °C, pH = 7.2) were used to estimate metal sorption capacities based on representative stormwater Cd and Zn concentrations. Cu was not considered, as very little of the metal is dissolved under these conditions (22.8 ± 7.1 %). The mean equilibrium sorption capacities for Cd (10.2 ± 3.1 mg/kg) and Zn (294.9 ± 14.9 mg/kg) far exceeded observed levels in the bioretention media such that the remaining sorption capacity was ≥83 % for Zn and ≥90 % for Cd for the cells. Overall, the results of this investigation suggest that bioretention cells can provide many years of effective infiltration (>6 years) and metals removal performance (>25 years).