Iron and silicon modified biochar for enhancing cadmium removal from water: Unveiling the crucial role of iron-induced silicon dissolution

Han Wu; Linan Liu; Yuguo Zhuo; Robert Mark Ellam; Keshuo Yan; Juncheng Liu; Jingchun Tang

doi:10.1016/j.biortech.2024.130745

Iron and silicon modified biochar for enhancing cadmium removal from water: Unveiling the crucial role of iron-induced silicon dissolution

Bioresour Technol. 2024 Jun:401:130745. doi: 10.1016/j.biortech.2024.130745. Epub 2024 Apr 25.

Authors

Han Wu¹, Linan Liu², Yuguo Zhuo³, Robert Mark Ellam⁴, Keshuo Yan¹, Juncheng Liu⁵, Jingchun Tang⁶

Affiliations

¹ MOE Key Laboratory of Pollution Processes and Environmental Criteria/Tianjin Engineering Center of Environmental Diagnosis and Contamination Remediation, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China.
² MOE Key Laboratory of Pollution Processes and Environmental Criteria/Tianjin Engineering Center of Environmental Diagnosis and Contamination Remediation, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China; Hebei Engineering Research Center for Ecological Restoration of Seaward Rivers and Coastal Waters, Hebei University of Environmental Engineering, Hebei 066102, China. Electronic address: liulinan@tju.edu.cn.
³ Hebei Engineering Research Center for Ecological Restoration of Seaward Rivers and Coastal Waters, Hebei University of Environmental Engineering, Hebei 066102, China.
⁴ Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China.
⁵ Tianjin Huakan Environmental Protection Technology Co., Ltd, Tianjin 300170, China.
⁶ MOE Key Laboratory of Pollution Processes and Environmental Criteria/Tianjin Engineering Center of Environmental Diagnosis and Contamination Remediation, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China. Electronic address: tangjch@nankai.edu.cn.

PMID: 38677381
DOI: 10.1016/j.biortech.2024.130745

Abstract

The interaction mechanisms of silicon (Si) and active ingredient iron (Fe) on cadmium (Cd) removal are still unknown. Herein, the Fe/Si modified biochar (Fe/Si-BC) was synthesized to enhance Cd removal by pre-immersion of Fe and ball milling loading of Si. Detailed characterizations indicated that Fe and Si were successfully introduced into Fe/Si-BC, resulting in the formation of a new metallic silicate (Ca_2.87Fe_0.13(SiO₃)₂). The maximum Cd adsorption capacity of Fe/Si-BC (31.66 mg g^-1) was 3.6 times and 2.5 times higher than that of Fe-BC (8.89 mg g^-1) and Si-BC (11.03 mg g^-1), respectively, deriving from an enhancement of Si dissolution induced by Fe introduction. The dissolved Si could capture and combine Cd to form CdSiO₃ precipitation, which was strongly supported by the random forest regression and correlation between dissolved Si content and Cd adsorption capacity. This study advances the mechanistic insights into synergistic functions of Si and Fe in Cd removal.

Keywords: Cd(Ⅱ) removal; CdSiO(3) precipitation; Fe/Si modified biochar; Si dissolution; Synergistic effect.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adsorption
Cadmium* / chemistry
Charcoal* / chemistry
Hydrogen-Ion Concentration
Iron* / chemistry
Silicon* / chemistry
Solubility*
Water Pollutants, Chemical* / isolation & purification
Water Purification* / methods

Substances

Cadmium
Silicon
biochar
Charcoal
Iron
Water Pollutants, Chemical