Adsorption Cd(Ⅱ) metal ions from aqueous solution using an economical and feasible zeolite from coal gangue: Adsorption performance, mechanism and economic assessment

Zhou, Yuzhi; Hu, Pian; Long, Linli; Sun, Jingyu; Wang, Boyu; Niu, Jingwei; Chen, Min; Chen, Xiaoyang

doi:.0..

DOI: https://doi.org/10.4491/eer.2024.693

Adsorption Cd(Ⅱ) metal ions from aqueous solution using an economical and feasible zeolite from coal gangue: Adsorption performance, mechanism and economic assessment

Yuzhi Zhou^1,2,3, Pian Hu¹, Linli Long¹, Jingyu Sun¹, Boyu Wang¹, Jingwei Niu¹, Min Chen⁴, and Xiaoyang Chen^1,2,3^†

¹School of Earth and Environment, Anhui University of Science and Technology, Huainan 232001, PR China
²Anhui Province Engineering Laboratory of Water and Soil Resources Comprehensive Utilization and Ecological Protection in High Groundwater Mining Area, Huainan 232001, PR China
³State Key Laboratory for Safe Mining of Deep Coal Resources and Environment Protection, Huainan 232001, PR China
⁴Taizhou Institute of Zhejiang University, Zhejiang University, Taizhou 318000, PR China

Corresponding Author: Xiaoyang Chen ,Tel: +86-554-6668045, Fax: +86-554-6668045, Email: chenxy@aust.edu.cn

Received: December 11, 2024; Accepted: May 10, 2025.

ABSTRACT

In this work, a novel coal gangue-derived zeolite (ZCG) was successfully fabricated through alkali fusion and hydrothermal processes, and was used as an adsorbent for the elimination of Cd(Ⅱ) from aqueous solution. Batch adsorption studies were performed at varying temperature (298.15 - 318.15 K), dosage (0.1 - 1.0 g/L), pH (2.0 - 7.0), time (15 - 1440 min) and Cd(Ⅱ) initial concentration (20 - 300 mg/L), respectively. The transformation of CG into ZCG resulted in an enhancement of surface area and ion-exchange sites, thus significantly enhancing adsorption performance. The Cd(Ⅱ) adsorption by ZCG followed the Langmuir model and pseudo second-order kinetic models, which indicated Cd(Ⅱ) adsorption of ZCG was monolayer chemisorption. The maximum adsorption capacity of the synthesized ZCG towards Cd(Ⅱ) was 66.49 mg/g, which was higher than that of CG (48.01 mg/g). SEM and XPS results demonstrated that the predominant mechanism of Cd(Ⅱ) removal by ZCG was ion exchange, and Cd2+ ions were mainly anchored on the Si-OH sites on ZCG. In a word, we envision that the ZCG will provide new pathway for developing cost-effective and high-efficient adsorbent materials for the purification of Cd(Ⅱ) and other pollutants, while minimizing the environmental footprints of current utilization of coal gangue.