Green remediation of benzene contaminated groundwater using persulfate activated by biochar composite loaded with iron sulfide minerals

Jin Zhu, Yinan Song, Liuwei Wang, Zhuorong Zhang, Jing Gao, Daniel C.W. Tsang, Yong Sik Ok, Deyi Hou

Research output: Journal article publicationJournal articleAcademic researchpeer-review


In this study, biochar supported iron sulfide (FexSy) composite (FexSy@biochar) was synthesized and utilized as a persulfate (PS) activator for benzene removal from contaminated groundwater. The FexSy@biochar/PS system exhibited excellent performance in benzene adsorption and subsequent degradation. The optimal conditions for benzene removal in this study were found to be 1 g L-1 FexSy@biochar dosage and 3 mM PS concentration (removal rate 99.8%), with no reversible desorption of benzene concentrations in a long-time interval. The high catalytic performance of FexSy@biochar was mainly attributed to the free radicals (i.e., SO4•−,·OH) generated from PS activation induced by FexSy particles on biochar, followed by the possible activation by oxygen-containing groups. The as-prepared FexSy@biochar also showed long-term effectiveness for PS activation as confirmed by the 4 test cycled tests. The EPR not only demonstrated the presence of OH and SO4•− free radicals but also indicated the sustainable release effect of reactive species from FexSy@biochar/PS system, as strong signals were observed in the FexSy@biochar/PS system even after 24 h. The FexSy@biochar could be an alternative to existing activators of in-situ chemical oxidation for contaminated groundwater remediation.

Original languageEnglish
Article number132292
JournalChemical Engineering Journal
Publication statusPublished - 1 Feb 2022


  • Benzene degradation
  • Engineered biochar
  • FeS nanoparticles
  • Groundwater contamination
  • Sulfate radicals
  • Sustainable remediation

ASJC Scopus subject areas

  • Chemistry(all)
  • Environmental Chemistry
  • Chemical Engineering(all)
  • Industrial and Manufacturing Engineering

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