Acetate anions intercalated Fe/Mg-layered double hydroxides modified biochar for efficient adsorption of anionic and cationic heavy metal ions from polluted water.

Autor: Li Y; School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China., Wang S; School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China., Ouyang XF; School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China., Dang Z; School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China; Key Laboratory of Ministry of Education on Pollution Control and Ecosystem Restoration in Industry Clusters, Guangzhou, 510006, China; Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Recycling, Guangzhou, 510006, China., Yin H; School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China; Key Laboratory of Ministry of Education on Pollution Control and Ecosystem Restoration in Industry Clusters, Guangzhou, 510006, China; Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Recycling, Guangzhou, 510006, China. Electronic address: huayin@scut.edu.cn.
Jazyk: angličtina
Zdroj: Chemosphere [Chemosphere] 2024 Aug; Vol. 362, pp. 142652. Date of Electronic Publication: 2024 Jun 25.
DOI: 10.1016/j.chemosphere.2024.142652
Abstrakt: The simultaneous removal of anionic and cationic heavy metals presents a challenge for adsorbents. In this study, acetate (Ac-) was utilized as the intercalating anion for layered double hydroxide (LDH) to prepare a novel biochar composite adsorbent (Ac-LB) designed for the adsorption of Pb(II), Cu(II), and As(V). By utilizing Ac- as the intercalating anion, the interlayer space of the LDH was enlarged from 0.803 nm to 0.869 nm, exposing more adsorption sites for the LDH and enhancing the affinity for heavy metals. The results of the adsorption experiments showed that the adsorption effect of Ac-LB on heavy metals was significantly improved compared to the original FeMg-LDH modified biochar composites (LB), and the maximum adsorption capacity of Pb(II), Cu(II), and As(V) were 402.70, 68.50, and 21.68 mg/g, respectively. Wastewater simulation tests further confirmed the promising application of Ac-LB for heavy metal adsorption. The analysis of the adsorption mechanism revealed that surface complexation, electrostatic adsorption, and chemical deposition were the main mechanisms of action between heavy metals (Pb(II) and Cu(II)) and Ac-LB. Additionally, Cu(II) ions underwent a homogeneous substitution reaction with Ac-LB. The adsorption process of As(V) by Ac-LB mainly relied on complexation and ion-exchange reactions. Lastly, the modification of the LDH structure by Ac - as an intercalating anion, thereby increasing the affinity for heavy metals, was further illustrated using density-functional theory (DFT) calculations.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
Externí odkaz: