School of Energy and Environmental Engineering, University of Science & Technology Beijing, Beijing, 100083, People's Republic of China.
Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science & Technology Beijing, Beijing, 100083, People's Republic of China.
Environ Sci Pollut Res Int. 2018 Nov;25(31):31272-31282. doi: 10.1007/s11356-018-3069-9. Epub 2018 Sep 7.
Heavy metal contamination, particularly vanadium contamination in mining and smelting areas, is a worldwide serious problem threatening the ecological system and human health. The contamination level of vanadium, arsenic, cadmium, chromium, mercury, and lead in sediments and waters in a vanadium mining area in China was investigated in the present study. The behavior of heavy metal uptake by 12 native aquatic macrophytes was evaluated, including 5 species of emergent aquatic plants (Acorus calamus, Scirpus tabernaemontani, Typha orientalis, Phragmites australis, and Bermuda grass), 3 species of floating plants (Marsilea quadrifolia, Nymphaea tetragona, and Eleocharis plantagineiformis), and 4 species of submerged plants (Hydrilla verticillata, Ceratophyllum demersum, Myriophyllum verticillatum, and Potamogetom crispus). Different heavy metal accumulation abilities were found across these macrophytes. Generally, they tended to accumulate higher contents of chromium, and C. demersum showed a particularly higher accumulation capacity for vanadium. The heavy metals were preferentially distributed in roots, instead of translocation into leaves and stems, indicating an internal detoxification mechanism for heavy metal tolerance in macrophytes. In 24-day laboratory hydroponic experiments, the macrophytes had a satisfied phytoremediation performance for heavy metals, when their concentrations were at the microgram per liter level. Particularly, vanadium was effectively removed by P. australis and C. demersum, the removal efficiencies of which were approximately 50%. In addition, a combination of terrestrial plant (Bermuda grass) and aquatic macrophytes (P. australis, M. quadrifolia, and C. demersum) exhibited high uptake capacity of all the six heavy metals and their residual concentrations were 95 (vanadium), 39.5 (arsenic), 4.54 (cadmium), 17.2 (chromium), 0.028 (mercury), and 7.9 (lead) μg/L, respectively. This work is of significant importance for introducing native macrophytes to remove low-level heavy metal contamination, particularly vanadium, and suggests phytoremediation as a promising and cost-effective method for in situ remediation at mining sites.
重金属污染，尤其是采矿和冶炼区的钒污染，是一个全球性的严重问题，威胁着生态系统和人类健康。本研究调查了中国某钒矿区沉积物和水体中钒、砷、镉、铬、汞和铅的污染水平。评估了 12 种本地水生植物对重金属的吸收行为，包括 5 种挺水植物（菖蒲、香蒲、东方香蒲、芦苇和百慕大草）、3 种浮叶植物（四叶菜、睡莲和水鳖）和 4 种沉水植物（黑藻、金鱼藻、菹草和凤眼莲）。这些水生植物对不同重金属的积累能力不同。一般来说，它们倾向于积累更高含量的铬，而 C. demersum 对钒的积累能力特别高。重金属优先分布在根部，而不是转移到叶片和茎部，这表明水生植物对重金属的耐受性具有内部解毒机制。在 24 天的实验室水培实验中，当重金属浓度处于微克/升水平时，这些植物对重金属表现出满意的植物修复性能。特别是，P. australis 和 C. demersum 有效地去除了钒，去除效率约为 50%。此外，陆地植物（百慕大草）和水生植物（P. australis、M. quadrifolia 和 C. demersum）的组合对所有六种重金属都具有较高的吸收能力，其残留浓度分别为 95（钒）、39.5（砷）、4.54（镉）、17.2（铬）、0.028（汞）和 7.9（铅）μg/L。这项工作对于引入本地水生植物去除低水平重金属污染，特别是钒污染具有重要意义，表明植物修复是一种有前途和具有成本效益的采矿场地原位修复方法。
