The large-scale, systematic introduction of urban stormwater into the subsurface could contaminate groundwater with metals including cadmium, copper, lead and zinc. To assess the potential for using manganese oxide-coated sand to remove metal ions during stormwater infiltration, batch and column tests were used to simulate conditions encountered in treatment systems. The geomedia exhibited a relatively high affinity for Zn, Cd and Pb at environmentally relevant conditions in batch tests. In column tests conducted in the absence of natural organic matter (NOM), dissolved Cu and Pb were removed for over 2000 pore volumes, whereas Zn and Cd were removed for several hundred pore volumes. In the presence of NOM, Cu and Pb removal diminished, but the adsorption of Zn and Cd decreased only slightly. Treating manganese oxide-coated sands with pH 3 hydrochloric acid after column tests recovered over 90% of the adsorbed Cd, Cu and Zn. It also restored the adsorptive capacity of the geomedia with minimal loss of the surface coating. Neither acids nor organic ligands removed significant amounts of adsorbed Pb from the geomedia. The results of this study imply that manganese oxide-coated sand can remove metal ions from stormwater, and that saturated geomedia can be regenerated with a mild acid solution.

中文翻译：

---

使用氧化锰涂层的砂去除雨水中的痕量金属离子

将城市雨水大规模，系统地引入地下可能会污染镉，铜，铅和锌等金属。为了评估在雨水渗透过程中使用氧化锰涂层的砂去除金属离子的潜力，使用批处理和柱测试来模拟处理系统中遇到的条件。在与环境相关的条件下，分批测试中，土工介质对Zn，Cd和Pb表现出相对较高的亲和力。在没有天然有机物（NOM）的情况下进行的柱测试中，去除了2000多个孔体积的溶解的Cu和Pb，而去除了数百个孔体积的Zn和Cd。在存在NOM的情况下，Cu和Pb的去除减少，但Zn和Cd的吸附仅略有下降。柱试验后，用pH 3盐酸处理氧化锰涂层的砂，回收了90％以上的吸附的Cd，Cu和Zn。它也以最小的表面涂层损失恢复了土工材料的吸附能力。酸和有机配体都不能从土工介质中去除大量吸附的Pb。这项研究的结果表明，用氧化锰涂层的砂可以除去雨水中的金属离子，并且可以用弱酸溶液再生饱和的土工介质。