Activation of percarbonate by water treatment sludge-derived biochar for the remediation of PAH-contaminated sediments

Chang-Mao Hung; Chin-Pao Huang; Chiu-Wen Chen; Chung-Hsin Wu; Yi-Li Lin; Cheng-Di Dong

doi:10.1016/j.envpol.2020.114914

Activation of percarbonate by water treatment sludge-derived biochar for the remediation of PAH-contaminated sediments

Environ Pollut. 2020 Oct;265(Pt B):114914. doi: 10.1016/j.envpol.2020.114914. Epub 2020 Jun 27.

Authors

Chang-Mao Hung¹, Chin-Pao Huang², Chiu-Wen Chen¹, Chung-Hsin Wu³, Yi-Li Lin⁴, Cheng-Di Dong⁵

Affiliations

¹ Department of Marine Environmental Engineering, National Kaohsiung University of Science and Technology, Kaohsiung City, Taiwan.
² Department of Civil and Environmental Engineering, University of Delaware, Newark, USA.
³ Department of Chemical and Materials Engineering, National Kaohsiung University of Science and Technology, Kaohsiung City, Taiwan.
⁴ Department of Safety, Health and Environmental Engineering, National Kaohsiung University of Science and Technology, Kaohsiung City, Taiwan.
⁵ Department of Marine Environmental Engineering, National Kaohsiung University of Science and Technology, Kaohsiung City, Taiwan. Electronic address: cddong@nkust.edu.tw.

PMID: 32806443
DOI: 10.1016/j.envpol.2020.114914

Abstract

Sludge from a groundwater treatment plant was used to prepare biochar by pyrolysis. The Fe-Mn rich biochar was used to activate percarbonate for the remediation of polycyclic aromatic hydrocarbons (PAHs) contaminated aquatic sediments. Results showed that the sludge-derived biochar (SBC) produced at a pyrolysis temperature of 700 °C was the most effective in activating percarbonate, which exhibited significant oxidative removal of PAHs. PAHs degradation took place via a Fenton-like oxidation manners, contributed from the Fe³⁺/Fe²⁺ and Mn³⁺/Mn²⁺ redox pairs, and achieved the highest degradation efficiency of 87% at pH₀ 6.0. Reactions between oxygenated functional groups of biochar and H₂O₂ generated of O₂^•- and HO• radicals in abundance under neutral and alkaline pH was responsible for the catalytic degradation of PAHs. Our results provided new insights into the environmental applications of SBC for the green sustainable remediation of organics-contaminated sediments and aided in reduction of associated environmental and health risk.

Keywords: Biochar; Percarbonate; Polycyclic aromatic hydrocarbon (PAH); Pyrolysis; Sludge.

MeSH terms

Carbonates
Charcoal
Hydrogen Peroxide
Sewage*
Water Purification*

Substances

Carbonates
Sewage
biochar
Charcoal
Hydrogen Peroxide
sodium percarbonate