New Insights into Interfacial Dynamics and Mechanisms of Biochar-Derived Dissolved Organic Matter on Arsenic Redistribution in Schwertmannite

Xiaofei Li; Tianfu Li; Yanfu Wei; Xiaohu Jin; Suresh C Pillai; Jun Zhang; Dian Chen; Xiaolian Wu; Yanping Bao; Xueding Jiang; Hailong Wang

doi:10.1016/j.envpol.2024.125419

New Insights into Interfacial Dynamics and Mechanisms of Biochar-Derived Dissolved Organic Matter on Arsenic Redistribution in Schwertmannite

Environ Pollut. 2024 Nov 28:125419. doi: 10.1016/j.envpol.2024.125419. Online ahead of print.

Authors

Xiaofei Li¹, Tianfu Li², Yanfu Wei³, Xiaohu Jin⁴, Suresh C Pillai⁵, Jun Zhang², Dian Chen², Xiaolian Wu², Yanping Bao², Xueding Jiang², Hailong Wang⁶

Affiliations

¹ School of Environmental and Chemical Engineering, Foshan University, Foshan 528000, PR China. Electronic address: xfli1103@fosu.edu.cn.
² School of Environmental and Chemical Engineering, Foshan University, Foshan 528000, PR China.
³ National Observation and Research Station of Coastal Ecological Environments in Macao, Macao Environmental Research Institute, Macau University of Science and Technology, Taipa, Macao 999078, China.
⁴ School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China.
⁵ Nanotechnology and Bio-Engineering Research Group, Department of Environmental Science, Atlantic Technological University, ATU Sligo, Ash Lane, Sligo, F91 YW50, Ireland.
⁶ School of Environmental and Chemical Engineering, Foshan University, Foshan 528000, PR China; Guangdong Provincial Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou, 510650, PR China.

PMID: 39615573
DOI: 10.1016/j.envpol.2024.125419

Abstract

Biochar is extensively utilized for the remediation of environments contaminated with heavy metals (HMs). However, its derived-dissolved organic matter (BDOM) can interact with iron oxides, which may adversely influence the retention of HMs. This study investigates the effect of BDOM derived from tobacco stalk (TS) and tobacco petiole (TP) biochar on the redistribution behavior of As(V) in acid mine drainage (AMD)-impacted environments, particularly concentrating on the interactions with Schwertmannite (Sch). Results showed that TP-BDOM, abundant in lignin-like compounds, led to a low-amplitude release of As(V) from Sch under acidic conditions, reaching a maximum value (19.84 μg L^-1), significantly lower than the release caused by TS-BDOM (87.46 μg L^-1). Subsequently, 88.2% of the released As(V) were re-adsorbed in the TS-BDOM system, while 47.5% were retained in the TP-BDOM system. XRD analysis, in conjunction with SEM and STEM characterizations, confirmed that there were no additional crystalline phases or alterations in the microscopic morphological features of the particles throughout the reaction process. In-situ ATR-FTIR, complemented by 2D-COS analysis, demonstrated that aromatic N-OH groups and carboxylic in BDOMs coordinated to As-Sch, enhancing sulfate and As(V) release. It was also noted that no As(III) was detected under the influences of TP- and TS-BDOM. XPS results indicated that As(V) remained the predominant redox species even in the presence of BDOMs. These findings enhance our insight into BDOM's role in As(V) fate and transport within AMD-contaminated environments.

Keywords: Biochar–derived dissolved organic matter; Schwermannite; arsenate; dissolution; redistribution.