Waste-wood-derived biochar cathode and its application in electro-Fenton for sulfathiazole treatment at alkaline pH with pyrophosphate electrolyte

Fengxia Deng; Hugo Olvera-Vargas; Orlando Garcia-Rodriguez; Yingshi Zhu; Jizhou Jiang; Shan Qiu; Jixian Yang

doi:10.1016/j.jhazmat.2019.05.077

Waste-wood-derived biochar cathode and its application in electro-Fenton for sulfathiazole treatment at alkaline pH with pyrophosphate electrolyte

J Hazard Mater. 2019 Sep 5:377:249-258. doi: 10.1016/j.jhazmat.2019.05.077. Epub 2019 May 28.

Authors

Fengxia Deng¹, Hugo Olvera-Vargas², Orlando Garcia-Rodriguez², Yingshi Zhu³, Jizhou Jiang⁴, Shan Qiu⁵, Jixian Yang⁶

Affiliations

¹ State Key Laboratory of Urban Water Resources Center, Department of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin, 150090, PR China; School of Chemical and Environmental Engineering, Jiang Han University, Wuhan, 430056, PR China.
² Centre for Water Research, Department of Civil and Environmental Engineering, National University of Singapore, 1 Engineering Dr. 2, Singapore 117576, Singapore.
³ State Key Laboratory of Urban Water Resources Center, Department of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin, 150090, PR China.
⁴ School of Environmental Ecology and Biological Engineering, Wuhan Institute of Technology, Wuhan 430205, PR China; School of Materials Science and Energy Engineering, Foshan University, Foshan 528000, PR China. Electronic address: 027wit@163.com.
⁵ State Key Laboratory of Urban Water Resources Center, Department of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin, 150090, PR China. Electronic address: qiushan@hit.edu.cn.
⁶ State Key Laboratory of Urban Water Resources Center, Department of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin, 150090, PR China. Electronic address: yangxj@hit.edu.cn.

PMID: 31170573
DOI: 10.1016/j.jhazmat.2019.05.077

Abstract

For the first time, a biomass-derived porous carbon cathode (WDC) was fabricated via a facile one-step pyrolysis of recovered wood-waste without any post-treatment. The WDC along with pyrophosphate (PP) as electrolyte were used in electro-Fenton (EF) at pH 8 for sulfathiazole (STZ) treatment. The H₂O₂ accumulation capacity of WDC was optimized via the following parameters: pyrolysis temperature, applied current and electrolyte. Results showed that the WDC cathode prepared at 900 °C achieved the highest H₂O₂ accumulation (13.80 mg L^-1 in 3 h) due to its larger electroactive surface area (28.81 cm²). Interestingly, it was found that PP decreased the decomposition rate of H₂O₂ in solution as compared to conventional electrolyte, which resulted in higher H₂O₂ accumulation. PP allowed operating EF at pH of 8 due to the formation of Fe²⁺-PP complexes in solution. Moreover, Fe²⁺-PP was able to activate oxygen to produce OH. In this way, the degradation of STZ took place through four main pathways: 1) via OH from the Fe²⁺-PP complex, 2) via OH from EF reactions, 3) via surface OH at the boron doped diamond electrode (BDD) and 4) via SO₄- from BDD activation. Finally, microtox tests revealed that some toxic intermediates were generated during WDC/BDD/PP EF treatment, but they were removed at the end of the process.

Keywords: BDD anode; Biomass-derived biochar carbons; Electro-fenton; Pyrophosphate (PP) electrolyte; Sulfathiazole.

Publication types

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

MeSH terms

Biomass
Charcoal / chemistry*
Diphosphates / chemistry*
Electrodes
Electrolytes
Ferric Compounds / chemistry
Free Radical Scavengers / chemistry
Hydrogen Peroxide
Hydrogen-Ion Concentration
Hydroxyl Radical
Iron
Solutions
Sulfathiazole / chemistry*
Wood / chemistry*

Substances

Diphosphates
Electrolytes
Fenton's reagent
Ferric Compounds
Free Radical Scavengers
Solutions
biochar
Charcoal
Hydroxyl Radical
Hydrogen Peroxide
Iron
Sulfathiazole