• Effect of Iron Activators on the Persulfate Oxidation of Polycyclic Aromatic Hydrocarbons (PAHs) in Contaminated Soils
  • Jiyeon Choi·Jungdo Park·Won Sik Shin*

  • School of Architectural, Civil, Environmental and Energy Engineering, Kyungpook National University, Daegu 41566, Korea

  • 다환방향족 탄화수소(PAHs) 오염토양의 과황산 산화 시 철 활성화제의 영향
  • 최지연·박정도·신원식*

  • 경북대학교 건설환경에너지공학부


PAHs commonly found in industrial sites such as manufactured gas plants (MGP) are potentially toxic, mutagenic and carcinogenic, and thus require immediate remediation. In-situ chemical oxidation (ISCO) is known as a highly efficient technology for soil and groundwater remediation. Among the several types of oxidants utilized in ISCO, persulfate has gained significant attention in recent years. Peroxydisulfate ion (S2O82-) is a strong oxidant with very high redox potential (E0 = 2.01 V). When mixed with Fe2+, it is capable of forming the sulfate radical (SO4-) that has an even higher redox potential (E0 = 2.6 V). In this study, the influence of various iron activators on the persulfate oxidation of PAHs in contaminated soils was investigated. Several iron sources such as ferrous sulfate (FeSO4), ferrous sulfide (FeS) and zero-valent iron (Fe(0)) were tested as a persulfate activator. Acenaphthene (ANE), dibenzofuran (DBF) and fluorene (FLE) were selected as model compounds because they were the dominant PAHs found in the field-contaminated soil collected from a MGP site. Oxidation kinetics of these PAHs in an artificially contaminated soil and the PAH-contaminated field soil were investigated. For all soils, Fe(0) was the most effective iron activator. The maximum PAHs removal rate in Fe(0)-mediated reactions was 92.7% for ANE, 83.0% for FLE, and 59.3% for DBF in the artificially contaminated soil, while the removal rate of total PAHs was 72.7% in the field-contaminated soil. To promote the iron activator effect, the effects of hydroxylamine as a reducing agent on reduction of Fe3+ to Fe2+, and EDTA and pyrophosphate as chelating agents on iron stabilization in persulfate oxidation were also investigated. As hydroxylamine and chelating agents (EDTA, pyrophosphate) dosage increased, the individual PAH removal rate in the artificially contaminated soil and the total PAHs removal rate in the field-contaminated soil increased. 

Keywords: Persulfate Oxidation, PAHs, Iron-activator, Hydroxylamine, Chelating agents

This Article

  • 2020; 25(1): 62-73

    Published on Mar 31, 2020

  • 10.7857/JSGE.2020.25.1.062
  • Received on Jan 17, 2020
  • Revised on Feb 12, 2020
  • Accepted on Mar 17, 2020

Correspondence to

  • Park·Won Sik Shin
  • School of Architectural, Civil, Environmental and Energy Engineering, Kyungpook National University, Daegu 41566, Korea

  • E-mail: wshin@knu.ac.kr