Highly effective removal of nickel ions from wastewater by calcium-iron layered double hydroxide

Ning Li; Mingjie Yuan; Sheng Lu; Xiaoli Xiong; Zhigang Xie; Yongsheng Liu; Wei Guan

doi:10.3389/fchem.2022.1089690

Highly effective removal of nickel ions from wastewater by calcium-iron layered double hydroxide

Front Chem. 2023 Jan 4:10:1089690. doi: 10.3389/fchem.2022.1089690. eCollection 2022.

Authors

Ning Li¹, Mingjie Yuan¹, Sheng Lu², Xiaoli Xiong¹, Zhigang Xie³, Yongsheng Liu¹, Wei Guan³

Affiliations

¹ Department of Chemistry and Chemical Engineering, College of Environment and Resource, Chongqing Technology and Business University, Chongqing, China.
² Department of Artificial Intelligence, Chongqing Technology and Business University, Chongqing, China.
³ Chongqing Key Laboratory of Environmental Materials and Remediation Technologies, Chongqing University of Arts and Sciences, Chongqing, China.

Abstract

Water pollution due to heavy metals has become a universal environmental problem. Ni(II) is a common heavy metal ion in polluted wastewater, which has high toxicity and carcinogenicity. In this study, the structure of a calcium-iron layered double hydroxide (Ca-Fe-LDHs) was synthesized and characterized by FTIR, XRD, SEM and XPS. Then, Ni(II) ion was effectively removed by Ca-Fe-LDHs and its mechanism for this materials was described. The maximum adsorption capacity of Ni(II) for Ca-Fe-LDHs was 418.9 mg‧g^-1 when the initial concentration of Ni(II) was 1 g/L. The adsorption and removal of Ni(II) by Ca-Fe-LDHs was attributed to the action of hydroxyl groups on the hydrotalcite, generating surface capture. Ni(OH)₂)0.75(H₂O)0.16(NiCO₃)0.09, Ni(OH)₂, NiO, NiSO₄ and other precipitates were generated on its surface. And a small amount of Ni-Fe-LDHs was generated through isomorphic transition before hydrolysis. Therefore, surface capture and isomorphic transition enhanced the removal efficiency of Ni(II) with Ca-Fe-LDHs, making Ca-Fe-LDHs as a potential material for effective removal of Ni(II).

Keywords: calcium-iron layered double hydroxide; heavy metal; isomorphic transition; mechanism; nickel ions.