Effect of two-dimensional electric field on the growth and cadmium uptake of Sedum plumbizincicola

• Published in: Separation and purification technology 2021-03, Vol.259, p.118121, Article 118121
• Main Authors: Fan, Guangping, Zhou, Dongmei, Zhang, Zhenhua, Ai, Yuchun, Zhang, Weiguo, Shi, Gaoling, Tong, Fei, Liu, Lizhu, Chen, Wei, Li, Jiangye, Gao, Yan
• Format: Article
• Language: English
• Subjects: Cd uptake; Electrokinetics; Phytoremediation; Plant growth; Sedum plumbizincicola
• ISSN: 1383-5866; 1873-3794
• DOI: 10.1016/j.seppur.2020.118121

•15 V voltage promoted the migration of Cd from bottom to surface layer but inhibited plant growth.•5 V treatment had little effect on plant growth but reduced the Cd availability in surface soil.•10 V voltage exhibited initial stimulative but subsequent inhibitory effect on plant growth.•10 V voltage enhanced the root uptake of Cd but reduced the translocation of Cd to shoot.•Electrical field intensity and current application time played a decisive role in EPKR system. Electrokinetic-assisted phytoremediation (EKPR) is an innovative technology to restore heavy metal contaminated soils. In this study, the effect of two-dimensional electric field on the growth and cadmium uptake of Sedum plumbizincicola and migration of cadmium (Cd) has been investigated in a laboratory experiment. After S. plumbizincicola growing for 30 d, four direct current electric fields with different voltages (0, 5, 10, 15 V) were applied intermittently (12 h on/12 h off) for 40 d. The results showed that 15 V voltage can promote the migration of Cd from bottom layer to surface layer, increase the availability of Cd in bottom and middle layers, and slightly reduce the availability of Cd in surface soil. However, it inhibited plant growth showing seriously reduced the chlorophyll content, increased the injury ratio of leaves at later growth stage and damaged the ultrastructure of root cells, thus hindered the plant uptake of Cd. The 5 V treatment had little effect the growth of S. plumbizincicola but did not increase the plant accumulation of Cd due to the decrease of Cd availability in soil. The 10 V of electric field enhanced the root uptake of Cd but reduced the translocation of Cd from root to shoot. The initial stimulative but subsequent inhibitory effect of 10 V voltage on plant growth indicated the current application time played a decisive role in the EKPR system. Therefore, it is necessary to choose appropriate electrode layout, electric field intensity and application time to maximize the phytoextraction efficiency in EKPR system.