Application of magnetite-activated persulfate oxidation for the degradation of PAHs in contaminated soils

M. Usman, P. Faure, C. Ruby, K. Hanna*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

157 Citations (Scopus)

Abstract

In this study, feasibility of magnetite-activated persulfate oxidation (AP) was evaluated for the degradation of polycyclic aromatic hydrocarbons (PAHs) in batch slurry system. Persulfate oxidation activated with soluble FeII (FP) or without activation (SP) was also tested. Kinetic oxidation of PAHs was tracked in spiked sand and in aged PAH contaminated soils at circumneutral pH. Quartz sand was spiked with: (i) single model pollutant (fluorenone) and (ii) organic extract isolated from two PAH contaminated soils (H and NM sampled from ancient coking plants) and was subjected to oxidation. Oxidation was also performed on real H and NM soils with and without an extraction pretreatment. Results indicate that oxidation of fluorenone resulted in its complete degradation by AP while abatement was very low (<20%) by SP or FP. In soil extracts spiked on sand, significant degradation of 16 PAHs was observed by AP (70-80%) in 1week as compared to only 15% by SP or FP systems. But no PAH abatement was observed in real soils whatever the treatment used (AP, FP or SP). Then soils were subjected to an extraction pretreatment but without isolation of organic extract from soil. Oxidation of this pretreated soil showed significant abatement of PAHs by AP. On the other hand, very low degradation was achieved by FP or SP. Selective degradation of PAHs was observed by AP with lower degradation efficiency towards high molecular weight PAHs. Analyses revealed that no by-products were formed during oxidation. The results of this study demonstrate that magnetite can activate persulfate at circumneutral pH for an effective degradation of PAHs in soils. However, availability of PAHs and soil matrix were found to be the most critical factors for degradation efficiency.

Original languageEnglish
Pages (from-to)234-240
Number of pages7
JournalChemosphere
Volume87
Issue number3
DOIs
Publication statusPublished - Apr 2012
Externally publishedYes

Keywords

  • Magnetite
  • Oxidation
  • Persulfate
  • Polycyclic aromatic hydrocarbons
  • Soil

ASJC Scopus subject areas

  • Environmental Engineering
  • Chemistry(all)
  • Environmental Chemistry
  • Pollution
  • Public Health, Environmental and Occupational Health
  • Health, Toxicology and Mutagenesis

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