Effect of different ramie (Boehmeria nivea L. Gaud) cultivars on the adsorption of heavy metal ions cadmium and lead in the remediation of contaminated farmland soils

Heavy metal ions, including cadmium (Cd) and lead (Pb), are serious pollutants in farmland soils. The effective removal of heavy metals is an important task in soil remediation. This study aimed to evaluate the ability of seven ramie (Boehmeria nivea L. Gaud) cultivars to remove heavy metals. Results showed that the seven ramie varieties grew well in Cd and Pb polluted soils. The aboveground biological tissues and raw fiber yield of Zhongzhu1 were 20.71 and 24.61 Mg ha(-1) per year, respectively, which were significantly higher than those of the six other varieties. Cd levels in each ramie part can be arranged as husks > root > stem bone > leaf > raw fiber, while Pb levels in each ramie part can be arranged as root > leaf > husks > stem bone > raw fiber. The Cd content in the shoots of Zhongzhu1 was 19.89 mg kg(-1), and the Pb content of the aboveground shoots of Shiqianzhugenma was 9.41 mg kg(-1). The extraction efficiency of Cd in Zhongzhu1 was greatly higher than those of the six other varieties. The extraction efficiency of Pb was similar in all varieties. Our observations suggest that ramie can be used to remove toxic ions (Cd and Pb). This study provides a new understanding of planting ramie for heavy metal removal from contaminated soils.

Automated summary

This study evaluated the ability of seven ramie cultivars to remove heavy metals and found that Zhongzhu1 had a higher extraction efficiency for cadmium compared to other varieties. However, the extraction efficiency of lead was similar across all varieties. The findings suggest that ramie can be used as a potential plant for heavy metal removal in contaminated soils.