Simulated photocatalytic aging of biochar in soil ecosystem: Insight into organic carbon release, surface physicochemical properties and cadmium sorption

Guixiang Quan; Qinya Fan; Liqiang Cui; Andrew R Zimmerman; Hailong Wang; Zhiyuan Zhu; Bin Gao; Limin Wu; Jinlong Yan

doi:10.1016/j.envres.2020.109241

Simulated photocatalytic aging of biochar in soil ecosystem: Insight into organic carbon release, surface physicochemical properties and cadmium sorption

Environ Res. 2020 Apr:183:109241. doi: 10.1016/j.envres.2020.109241. Epub 2020 Feb 7.

Authors

Guixiang Quan¹, Qinya Fan², Liqiang Cui², Andrew R Zimmerman³, Hailong Wang⁴, Zhiyuan Zhu², Bin Gao⁵, Limin Wu², Jinlong Yan⁶

Affiliations

¹ School of Environmental Science and Engineering, Yancheng Institute of Technology, Yancheng, 224051, China; Department of Agricultural and Biological Engineering, University of Florida, Gainesville, FL, 32611, USA.
² School of Environmental Science and Engineering, Yancheng Institute of Technology, Yancheng, 224051, China.
³ Department of Geological Sciences, University of Florida, Gainesville, FL, 32611, USA.
⁴ School of Environmental and Chemical Engineering, Foshan University, Foshan, Guangdong, 528000, China; Key Laboratory of Soil Contamination Bioremediation of Zhejiang Province, School of Environmental and Resource Sciences, Zhejiang A&F University, Hangzhou, Zhejiang, 311300, China.
⁵ Department of Agricultural and Biological Engineering, University of Florida, Gainesville, FL, 32611, USA.
⁶ School of Environmental Science and Engineering, Yancheng Institute of Technology, Yancheng, 224051, China. Electronic address: yjlyt@ycit.cn.

PMID: 32062184
DOI: 10.1016/j.envres.2020.109241

Abstract

Photochemical/photocatalytic reaction, one of the aging pathway of biochar in soil, not only changed the physicochemical properties of biochar, but also affected the migration and transformation of pollutants. Wheat straw biochar was photocatalytic aged in a Fenton-like system using organic acid as buffer solution under light sources, the organic carbon release and surface chemical changes of biochar were investigated to illustrate the adsorption behaviors. With Fe(III) or α-Fe₂O₃ added, the total organic carbon (TOC) of aged biochar solution was influenced more by buffer system than light sources, with the highest of 420.59 mg L^-1 in citric acid system. The production of the hydroxyl radical (OH·) at citric/Fe(III) system was higher than the oxalic/Fe(III) system under the Hg lamp and showed an increasing trend with time. With light exposure, the porous structure of the biochar altered and surface area increased from 7.613 to 29.74 m² g^-1. Meanwhile, the adsorption of cadmium ion by biochar aged in citric/Fe(III) system also showed an increased adsorption capacity with a maximum of 73.54 mg g^-1. So, a well understanding of biochar physicochemical properties changes under natural ecosystem was undoubtedly useful for scientific assessment the long-term feasibility of biochar as soil remediation.

Keywords: Adsorption; Biochar; Cadmium; Hydroxyl radical; Photocatalytic.

Publication types

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

MeSH terms

Adsorption
Cadmium
Carbon
Charcoal*
Ecosystem*
Ferric Compounds
Soil Pollutants*
Soil*

Substances

Ferric Compounds
Soil
Soil Pollutants
biochar
Cadmium
Charcoal
Carbon