Remediation of cadmium contaminated soil using K2FeO4 modified vinasse biochar

Yinchen Da; Min Xu; Jing Ma; Peng Gao; Xiaohong Zhang; Gang Yang; Jun Wu; Chun Song; Lulu Long; Chao Chen

doi:10.1016/j.ecoenv.2023.115171

Remediation of cadmium contaminated soil using K₂FeO₄ modified vinasse biochar

Ecotoxicol Environ Saf. 2023 Jun 20:262:115171. doi: 10.1016/j.ecoenv.2023.115171. Online ahead of print.

Authors

Yinchen Da¹, Min Xu², Jing Ma³, Peng Gao⁴, Xiaohong Zhang¹, Gang Yang¹, Jun Wu¹, Chun Song¹, Lulu Long¹, Chao Chen¹

Affiliations

¹ College of Environmental Science, Sichuan Agricultural University, Chengdu 611130, China.
² College of Environmental Science, Sichuan Agricultural University, Chengdu 611130, China. Electronic address: xumin_xyz@126.com.
³ College of Water Conservancy and Hydropower Engineering, Sichuan Agricultural University, Ya'an 625014, China.
⁴ Department of Environmental and Occupational Health, and Department of Civil and Environmental Engineering, University of Pittsburgh, Pittsburgh 15261, USA.

PMID: 37348221
DOI: 10.1016/j.ecoenv.2023.115171

Abstract

The remediation of cadmium (Cd) contaminated soil is challenging for agricultural practices. In this study, a novel vinasse biochar modified by potassium ferrate (K₂FeO₄) was synthesized to immobilize Cd in agricultural soil. Three biochars [i.e., vinasse biochar (BC), KMnO₄ modified vinasse biochar (MnBC), and K₂FeO₄ modified vinasse biochar (FeBC)] were applied to compare their efficiencies of Cd immobilization. The results showed that the orders of pH, ash content, and functional groups in different biochar were the same following BC < MnBC < FeBC. Scanning electron microscope images showed that the FeBC has more micropores than MnBC and BC. X-ray diffraction identified manganese oxides and iron oxides within MnBC and FeBC, indicating that Mn and Fe were well loaded on the biochar. In the soil-based pot experiment, both MnBC and FeBC significantly reduced soil available Cd by 23-38% and 36-45% compared with the control, respectively (p < 0.05). In addition, the application of BC, MnBC, and FeBC significantly increased the yield, chlorophyll, and vitamin C of Chinese cabbage (p < 0.05), and decreased its Cd uptake compared with the control. Notably, shoot Cd significantly reduced when 2% FeBC was applied (p < 0.05). Overall, using K₂FeO₄ to modify vinasse biochar enriched the surface functional groups and minerals as well as reduced Cd availability in soil and its uptake by the plant. Our study showed that K₂FeO₄ modified vinasse biochar could be used as an ideal amendment for the remediation of Cd-contaminated soil.

Keywords: Chinese cabbage; Fe-modified biochar; Potassium ferrate; Potassium permanganate; Soil remediation.