H3PO4 activation mediated the iron phase transformation and enhanced the removal of bisphenol A on iron carbide-loaded activated biochar

Nan Zhao; Kunyuan Liu; Chao He; Dongye Zhao; Ling Zhu; Chuanfang Zhao; Weihua Zhang; Wen-Da Oh; Weixian Zhang; Rongliang Qiu

doi:10.1016/j.envpol.2022.118965

H₃PO₄ activation mediated the iron phase transformation and enhanced the removal of bisphenol A on iron carbide-loaded activated biochar

Environ Pollut. 2022 May 1:300:118965. doi: 10.1016/j.envpol.2022.118965. Epub 2022 Feb 5.

Authors

Nan Zhao¹, Kunyuan Liu², Chao He², Dongye Zhao³, Ling Zhu⁴, Chuanfang Zhao⁵, Weihua Zhang¹, Wen-Da Oh⁶, Weixian Zhang⁷, Rongliang Qiu⁸

Affiliations

¹ School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou, 510275, PR China; Guangdong Provincial Key Lab of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou, 510275, PR China.
² School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou, 510275, PR China.
³ Department of Civil & Environmental Engineering, Auburn University, Auburn, AL, 36849, USA.
⁴ State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, PR China.
⁵ Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, PR China.
⁶ School of Chemical Sciences, Universiti Sains Malaysia, 11800, Penang, Malaysia.
⁷ State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, PR China; Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, PR China.
⁸ School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou, 510275, PR China; Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, PR China; Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou, 510642, PR China. Electronic address: eesqrl@mail.sysu.edu.cn.

PMID: 35134429
DOI: 10.1016/j.envpol.2022.118965

Abstract

Zero valent iron-loaded biochar (Fe⁰-BC) has shown promise for the removal of various organic pollutants, but is restricted by reduced specific surface area, low utilization efficiency and limited production of reactive oxygen species (ROS). In this study, iron carbide-loaded activated biochar (Fe₃C-AB) with a high surface area was synthesized through the pyrolysis of H₃PO₄ activated biochar with Fe(NO₃)₃, tested for removing bisphenol A (BPA) and elucidated the adsorption and degradation mechanisms. As a result, H₃PO₄ activated biochar was beneficial for the transformation of Fe⁰ to Fe₃C. Fe₃C-AB exhibited a significantly higher removal rate and removal capacity for BPA than that of Fe⁰-BC within a wide pH range of 5.0-11.0, and its performance was maintained even under extremely high salinity and different water sources. Moreover, X-ray photoelectron spectra and density functional theory calculations confirmed that hydrogen bonds were formed between the COOH groups and BPA. ¹O₂ was the major reactive species, constituting 37.0% of the removal efficiency in the degradation of BPA by Fe₃C-AB. Density functional reactivity theory showed that degradation pathway 2 of BPA was preferentially attacked by ROS. Thus, Fe₃C-AB with low cost and excellent recycling performance could be an alternative candidate for the efficient removal of contaminants.

Keywords: Degradation pathway; Fe(3)C-Loaded activated biochar; H(3)PO(4) activation; Hydrogen bond; Singlet oxygen degradation.

MeSH terms

Adsorption
Benzhydryl Compounds
Carbon Compounds, Inorganic
Charcoal / chemistry
Iron Compounds
Iron* / chemistry
Phenols
Water Pollutants, Chemical* / analysis

Substances

Benzhydryl Compounds
Carbon Compounds, Inorganic
Iron Compounds
Phenols
Water Pollutants, Chemical
biochar
iron carbide
Charcoal
Iron
bisphenol A