Elucidating the redox-driven dynamic interactions between arsenic and iron-impregnated biochar in a paddy soil using geochemical and spectroscopic techniques

Xing Yang; Sabry M Shaheen; Jianxu Wang; Deyi Hou; Yong Sik Ok; Shan-Li Wang; Hailong Wang; Jörg Rinklebe

doi:10.1016/j.jhazmat.2021.126808

Elucidating the redox-driven dynamic interactions between arsenic and iron-impregnated biochar in a paddy soil using geochemical and spectroscopic techniques

J Hazard Mater. 2022 Jan 15:422:126808. doi: 10.1016/j.jhazmat.2021.126808. Epub 2021 Aug 16.

Authors

Xing Yang¹, Sabry M Shaheen², Jianxu Wang³, Deyi Hou⁴, Yong Sik Ok⁵, Shan-Li Wang⁶, Hailong Wang⁷, Jörg Rinklebe⁸

Affiliations

¹ Biochar Engineering Technology Research Center of Guangdong Province, School of Environmental and Chemical Engineering, Foshan University, Foshan, Guangdong 528000, China; University of Wuppertal, School of Architecture and Civil Engineering, Institute of Foundation Engineering, Water, and Waste-Management, Laboratory of Soil, and Groundwater-Management, Pauluskirchstraße 7, 42285 Wuppertal, Germany.
² University of Wuppertal, School of Architecture and Civil Engineering, Institute of Foundation Engineering, Water, and Waste-Management, Laboratory of Soil, and Groundwater-Management, Pauluskirchstraße 7, 42285 Wuppertal, Germany; King Abdulaziz University, Faculty of Meteorology, Environment, and Arid Land Agriculture, Department of Arid Land Agriculture, Jeddah 21589, Saudi Arabia; University of Kafrelsheikh, Faculty of Agriculture, Department of Soil and Water Sciences, 33 516 Kafr El-Sheikh, Egypt.
³ State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China.
⁴ Tsinghua University, School of Environment, Beijing 100084, China.
⁵ Korea Biochar Research Center, APRU Sustainable Waste Management & Division of Environmental Science and Ecological Engineering, Korea University, Seoul, Republic of Korea.
⁶ Department of Agricultural Chemistry, National Taiwan University, 1 Sect. 4, Roosevelt Rd., Taipei 10617, Taiwan, ROC.
⁷ Biochar Engineering Technology Research Center of Guangdong Province, School of Environmental and Chemical Engineering, Foshan University, Foshan, Guangdong 528000, China; Key Laboratory of Soil Contamination Bioremediation of Zhejiang Province, Zhejiang A&F University, Hangzhou, Zhejiang 311300, China. Electronic address: hailong.wang@fosu.edu.cn.
⁸ University of Wuppertal, School of Architecture and Civil Engineering, Institute of Foundation Engineering, Water, and Waste-Management, Laboratory of Soil, and Groundwater-Management, Pauluskirchstraße 7, 42285 Wuppertal, Germany; University of Sejong, Department of Environment, Energy and Geoinformatics, Seoul, Guangjin-Gu 05006, Republic of Korea. Electronic address: rinklebe@uni-wuppertal.de.

PMID: 34399221
DOI: 10.1016/j.jhazmat.2021.126808

Abstract

Iron (Fe)-modified biochar, a renewable amendment that synthetizes the functions of biochar and Fe materials, demonstrates a potential to remediate arsenic (As)-contaminated soils. However, the effectiveness of Fe-based biochar to immobilize As in paddy soils under varying redox conditions (Eh) has not been quantified. We tested the capability of the raw (RBC) and Fe-impregnated (FeBC) biochars to immobilize As in a paddy soil under various Eh conditions (from -400 to +300 mV) using a biogeochemical microcosm system. In the control, As was mobilized (686.2-1535.8 μg L^-¹) under reducing conditions and immobilized (61.6-71.1 μg L^-¹) under oxidizing conditions. Application of FeBC immobilized As at Eh < 0 mV by 32.6%-81.1%, compared to the control, because of the transformation of As-bound Fe (hydro)oxides (e.g., ferrihydrite) and the formation of complexes (e.g., ternary As-Fe-DOC). Application of RBC immobilized As at Eh < -100 mV by 16.0%-41.3%, compared to the control, due to its porous structure and oxygen-containing functional groups. Mobilized As at Eh > +200 mV was caused by the increase of pH after RBC application. Amendment of the Fe-modified biochar can be a suitable approach for alleviating the environmental risk of As under reducing conditions in paddy soils.

Keywords: Fe-based biochar; Immobilization mechanisms; Redox conditions; Soil remediation; Toxic metal(loid)s.

Publication types

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

MeSH terms

Arsenic* / analysis
Charcoal
Iron
Oryza*
Oxidation-Reduction
Soil
Soil Pollutants* / analysis

Substances

Soil
Soil Pollutants
biochar
Charcoal
Iron
Arsenic