Plants are the crucial component of floating treatment wetlands (FTWs). However, heavy metal removal capacity varies between plant species, and the relationships between plant traits and differences in removal capacity remain unclear. This study sought to determine: (1) the relationships between plant traits and removal of Cd, Cu, Pb, and Zn from water, and (2) the relationships between the removal patterns of these metals. Plants of 34 wetland plant species were exposed to heavy metal concentrations common in stormwater for five days, and 20 traits were measured on each plant. Results indicate that the most important plant traits for heavy metal removal from water are transpiration and high total biomass, especially large amounts of fine roots and leaves. The same traits were generally related to removal both initially and after longer exposure, with stronger correlations found after longer exposure. Plant removal of one metal was likely correlated with removal of the other metals, and the plant removal capacity after 30 min of exposure was correlated with the removal capacity five days later. The present results can be used in selecting plants for enhanced heavy metal removal by FTWs and in identifying additional useful plant species, allowing adaptation to local conditions.

中文翻译：

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植物性状与湿地植物的重金属去除能力有关。

植物是漂浮处理湿地（FTW）的关键组成部分。然而，重金属的去除能力因植物种类而异，并且植物性状与去除能力差异之间的关系仍不清楚。本研究试图确定：（1）植物性状与从水中去除Cd，Cu，Pb和Zn的关系，以及（2）这些金属的去除方式之间的关系。将34种湿地植物物种的植物暴露于雨水中常见的重金属浓度下5天，并对每种植物测量20个性状。结果表明，从水中去除重金属最重要的植物性状是蒸腾作用和高总生物量，尤其是大量的细根和叶。通常，相同的性状与最初接触和长时间接触后的去除有关，暴露时间越长，相关性越强。一种金属的植物去除可能与另一种金属的去除相关，暴露30分钟后的植物去除能力与五天后的去除能力相关。本结果可用于选择通过FTW增强重金属去除的植物，并用于确定其他有用的植物物种，从而适应当地条件。