Insights into the effect of cations on cathodic behavior and microstructure in cadmium electrochemical recovery process. (April 2022)

• Record Type: Journal Article
• Authors: Xia, Liu; Zhang, Wenjuan; Che, Jianyong; Chen, Jun; Wen, Peicheng; Ma, Baozhong; Wang, Chengyan
• Is Part Of: Chemosphere. Volume 292(2022)
• Publication Date: 2022-04
• Subjects: Cadmium recovery -- Cations -- Electrochemical behavior -- Electrode parameters -- Microstructure; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2021.133423
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Secondary resources provide an essential source for cadmium recovery, but also bring severe environmental problems. Due to the short process and high product purity, electrodeposition is suitable for realizing the reduction, reuse, and recycling of cadmium, while the complex composition of the resources contributes to a complicated electrochemical system. In this work, the effect of common cations (Cu 2+, Ni 2+, Fe 2+, and Zn 2+ ) on cadmium electrochemical recovery was investigated from the perspective of electrochemical behavior and microstructure. The results indicated that Cu affected the electrochemical process most prominently, which was deposited on the cathode and formed microcell with Cd, not only impeding the recovery of Cd, but also influencing the purity severely. Comparatively, Ni showed a relatively minor effect, which made the formal potential more negative and alleviated cathodic polarization to some degree. Besides, Fe 2+ was oxidized by the oxygen released from the anode, and followed by the reaction with Cd, resulting in the redissolution of Cd. With respect to Zn, a low concentration of Zn (≤1 g L −1 ) had little influence on electrochemical behavior of Cd, while it was deposited simultaneously with Cd on the cathode at a high concentration (5 g L −1 ). Based on the microstructural characterization, the lithops-like cathode cadmium grew up in the presence of Cu, while dendritic Cd was formed affected by Zn, Fe 2+, and Ni, especially Fe 2+ . Graphical abstract: Image 1 Highlights: Effect of common impurities on electrochemical performance of Cd was clarified. The detailed electrode parameters affected by impurities were obtained. Cu affected the quality of Cd severely due to the formation of microcell. The oxidation of Fe 2+ caused the redissolution and dendritic growth of Cd. Ni and low concentration of Zn had little effect on electrochemical recovery of Cd.