Heavy metals are very important environmental pollutants, which poses a serious threat to aquatic biology and humans, especially in lake basins under high anthropogenic pressure. In China, metal mining has caused severe heavy metal pollution, particularly in the Middle- Lower Yangtze Plain.
Phytoremediation is an emerging cost-effective and eco-friendly technology that utilizes plants to remove, transform, or stabilize a variety of contaminants located in water, sediments, or soils. Submerged macrophytes possess significant potential to bioconcentrate heavy metals due to their greater surface area as compared to non-submerged plants; however, some submerged macrophytes cannot tolerate eutrophication for a long time. Therefore, directly selecting submerged macrophytes with high accumulation capability in eutrophic lakes is a more realistic way to identify plants suitable for water remediation by removal of heavy metals.
Dr. XING Wei under the supervision of Professor LIU Guihua from Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden investigated submerged macrophytes with high accumulation capability from 24 eutrophic lakes along the middle and lower reaches of the Yangtze River. Results showed that these eutrophic lakes have large amounts of heavy metals in both water and sediments because of human activities. Najas marina is a hyperaccumulator of As and Cd, Ceratophyllum demersum is a hyperaccumulator of Co, Cr and Fe, and Vallisneria natansis a hyperaccumulator of Pb.Therefore, N. marina, C. demersum and V. natans are good candidate species for removing heavy metals from eutrophic lakes.
The paper entitled “Bioaccumulation of heavy metals by submerged macrophytes: looking for hyperaccumulator in eutrophic lakes” was published online in Environmental Science & Technology (DOI: 10.1021/es303923w). This study was supported by National Natural Science Foundation of China (31000163), the National S & T Major Project (2012ZX07103003) and Youth Innovation Promotion Association of CAS.
Hyperaccumulators in Eutrophic Lakes and technical route (image by Professor LIU Guihua’s group)
