Outstanding fluoride removal from aqueous solution by a La-based adsorbent

Weisen Yang; Fengshuo Shi; Wenlong Jiang; Yuhuang Chen; Kaiyin Zhang; Shaoju Jian; Shaohua Jiang; Chunmei Zhang; Jiapeng Hu

doi:10.1039/d2ra06284d

Outstanding fluoride removal from aqueous solution by a La-based adsorbent

RSC Adv. 2022 Oct 26;12(47):30522-30528. doi: 10.1039/d2ra06284d. eCollection 2022 Oct 24.

Authors

Weisen Yang¹, Fengshuo Shi¹, Wenlong Jiang¹, Yuhuang Chen¹, Kaiyin Zhang², Shaoju Jian¹, Shaohua Jiang^{1

3}, Chunmei Zhang⁴, Jiapeng Hu¹

Affiliations

¹ Fujian Key Laboratory of Eco-Industrial Green Technology, College of Ecology and Resources Engineering, Wuyi University Wuyishan 354300 China jianshaoju@126.com wyuwqhjp@163.com.
² College of Mechanical and Electrical Engineering, Wuyi University Wuyishan 354300 China.
³ Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, International Innovation Center for Forest Chemicals and Materials, College of Materials Science and Engineering, Nanjing Forestry University Nanjing 210037 China.
⁴ Institute of Materials Science and Devices, School of Materials Science and Engineering, Suzhou University of Science and Technology Suzhou 215009 China cmzhang@usts.edu.cn.

Abstract

A La-based adsorbent was prepared with La(NO₃)₃·6H₂O, 2-methylimidazole and DMF via amide-hydrolysis and used for fluoride decontamination from aqueous water. The obtained adsorbent was lanthanum methanoate (La(COOH)₃). The effects of pH value, initial F^- concentration and interfering ions on defluoridation properties of as-prepared La(COOH)₃ were assessed through batch adsorption tests. The adsorption kinetics, isotherm models and thermodynamics were employed to verify the order, nature and feasibility of La(COOH)₃ towards fluoride removal. The results imply that La(COOH)₃ is preferable for defluoridation over a wide pH range of 2 to 9 without interference. Simultaneously, the defluoridation process of La(HCOO)₃ accords to the pseudo-second order model and Langmuir isotherm, revealing chemical adsorption is the main control step. The maximum fluoride capture capacities of La(COOH)₃ at 30, 40 and 50 °C are 245.02, 260.40 and 268.99 mg g^-1, respectively. The mechanism for defluoridation by La(COOH)₃ was revealed by PXRD and XPS. To summarize, the as-synthesized La based adsorbent could serve as a promising adsorbent for defluoridation from complex fluoride-rich water.