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Quantitative analysis on the mechanism of Cd2+ removal by MgCl2-modified biochar in aqueous solutions.
- Source :
-
Journal of Hazardous Materials . Oct2021, Vol. 420, pN.PAG-N.PAG. 1p. - Publication Year :
- 2021
-
Abstract
- In this study, a pristine biochar (BC) and MgCl 2 -modified biochar (MBC) were prepared using Pennisetum sp. straw for removing Cd2+ from aqueous solutions. Scanning electron microscope (SEM) imaging combined with energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), as well as the surface area and porosity analyses were used to reveal the physico-chemical characteristics of the pristine and modified adsorbents. Results suggested that MgCl 2 impregnation during the synthesis had enhanced the specific surface area and pore volume of the biochar. Batch adsorption experiments indicated that the Cd2+ adsorption data of MBC fitted the Langmuir isothermal and pseudo-second order kinetic models, indicating a chemical adsorption was undergoing in the system. The maximum adsorption capacity of Cd2+ on MBC was 763.12 mg/g, which was 11.15 times higher than that of the pristine BC. The Cd2+ removal by MBC was mainly attributed to the mechanisms in an order: Cd(OH) 2 precipitation (73.43%) > ion exchange (22.67%) > Cd2+-π interaction (3.88%), with negligible contributions from functional group complexation, electrostatic attraction and physical adsorption. The MBC could thus be used as a promising adsorbent for Cd2+ removal from aqueous solutions. [Display omitted] • MgCl 2 modification increased the specific surface area and pore volume of biochar. • MgCl 2 -modified biochar removed 763.12 mg/g Cd2+ from polluted water. • Cd(OH) 2 precipitation dominated the Cd2+ removal mechanism. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 03043894
- Volume :
- 420
- Database :
- Academic Search Index
- Journal :
- Journal of Hazardous Materials
- Publication Type :
- Academic Journal
- Accession number :
- 152554003
- Full Text :
- https://doi.org/10.1016/j.jhazmat.2021.126487