A novel biochar composite derived from oil-based drill sludge and cuttings: Structural characterization and electrochemical properties

Qi Feng; Jianhua Shu; Zao Jiang; Mohamed Gamal El-Din; Yu Hao; Wenwen Tan; Chenglun Liu; Longjun Xu

doi:10.1016/j.envres.2023.116757

A novel biochar composite derived from oil-based drill sludge and cuttings: Structural characterization and electrochemical properties

Environ Res. 2023 Nov 1;236(Pt 2):116757. doi: 10.1016/j.envres.2023.116757. Epub 2023 Jul 28.

Authors

Qi Feng¹, Jianhua Shu², Zao Jiang³, Mohamed Gamal El-Din⁴, Yu Hao⁵, Wenwen Tan⁶, Chenglun Liu⁷, Longjun Xu⁸

Affiliations

¹ State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing, 400044, China. Electronic address: qifeng868@cqu.edu.cn.
² Army Logistical University of PLA, Chongqing, 401331, China. Electronic address: 285191822@qq.com.
³ State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing, 400044, China. Electronic address: 1014736068@qq.com.
⁴ Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta, T6G 1H9, Canada. Electronic address: mgamalel-din@ualberta.ca.
⁵ School of Resources and Security, Chongqing Vocational Institute of Engineering, Chongqing, 402260, China. Electronic address: hylgd2004@126.com.
⁶ State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing, 400044, China. Electronic address: 1395230593@qq.com.
⁷ State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing, 400044, China; College of Chemistry and Chemical Engineering, Chongqing University, Chongqing, 401331, China. Electronic address: xlclj@cqu.edu.cn.
⁸ State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing, 400044, China. Electronic address: xulj@cqu.edu.cn.

PMID: 37517484
DOI: 10.1016/j.envres.2023.116757

Abstract

How to dispose of large quantities of hazardous shale gas drilling waste is an important worldwide problem facing the oil and gas industry. In this study, we report an environmentally friendly and low energy consumption approach (carbonization followed by activation) to convert oil-based drill sludge (OBDS) and oil-based drill cuttings (OBDCs) into biochar composites and investigate the effect of hydrofluoric acid (HF) acidification on them. The biochar composites were prepared using the OBDS, OBDCs, the mixtures of OBDS and OBDCs, and HF treatment the mixtures were named OS, OC, OSC, and OSC-HF, respectively. The characterization result of synthesized biochar composites indicated that the OSC had a larger specific surface area and a higher degree of graphitization. The composites mainly consisted of SiO₂ and BaSO₄, except for biochar. The OSC electrode exhibited the highest oxygen evolution potential (1.72 V vs Ag/AgCl) and the lowest charge transfer resistance compared with OS, OC, and OSC-HF electrodes, implying that SiO₂ plays an important role in electrochemical performance. Using the OSC electrode as an anode, the chemical oxygen demand removal efficiency of the OBDS supernatant was 79.4 ± 0.95%. Further, the OSC electrode could maintain higher degradation efficiency and stability after the fifth reuse. The study provides a promising route for the proper disposal and resource utilization of OBDS and OBDCs and proposes a novel biochar compound as an electrode for the efficient treatment of wastewater. Moreover, this work highlights the important significance of the simultaneous resource utilization of waste and the treatment of wastewater using waste materials.

Keywords: Biochar composites; Electrochemical properties; Oil-based drill cuttings; Oil-based drill sludge; Structural characterization.