Mercury Uptake and Transport by Plants in Aquatic Environments: A Meta-Analysis

The use of phytoremediation technology to remove heavy metal ions from aquatic environments or reduce their toxicity offers the possibility of restoring the ecological environment of polluted water bodies. Based on available literature on heavy metal absorption by aquatic plants, we conducted a meta-analysis to study the absorptive capacities of different plants as well as the factors that influence their Hg-absorption performance. Seventeen plant families, including Araceae, Haloragaceae, Hydrocharitaceae, and Poaceae, have a strong Hg-absorption capacity. The root systems of aquatic plants belonging to these families are primarily responsible for this remediation function, and only a limited proportion of Hg+ that enters a plant via the root system is transferred to other plant organs. Additionally, the diversity of plant life habits (e.g., floating, submerged, and emergent) and the water pH significantly influence the ability of plants to absorb Hg. It is expected that this study will provide a reference for the cultivation of aquatic plants for restoring the ecological environment of Hg-polluted water bodies.