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Keywords:

  • Contaminated soil;
  • tar oil;
  • heterocyclic aromatic hydrocarbons;
  • contaminant profile;
  • biodegradation;
  • comprehensive two-dimensional gas chromatography;
  • principal component analysis

Abstract

BACKGROUND: Coal tar is a complex mixture of more than 100 compounds, including polycyclic aromatic hydrocarbons (PAHs), alkylated PAHs, phenolic as well as NSO-heterocyclic compounds (HAC). Many of these are associated with human and environmental risk. Information concerning the environmental fate of coal tar constituents, apart from the 16 PAHs listed as priority substances by the US-EPA, is scarce. In the current study, aerobic degradation of aromatic tar oil constituents in ten historically contaminated soils was monitored under laboratory conditions using two-dimensional comprehensive GC2/ MS.

RESULTS: Fifty-four aromatic compounds were detected in one single analysis. Degradation behavior of individual compounds was determined by their hydrophobicity, molecular size, degree of alkylation and isomeric conformation. Eight substances, including six US-EPA PAHs and two benzofluorene isomers, were identified in nine out of ten soils as principal components in the residual contamination after degradation.

CONCLUSION: Using GC2/ MS to reveal the degradation behavior of distinct coal tar constituents and applying PCA to identify contaminants resistant to microbial degradation can be useful for the optimization of bioremediation measures at contaminated sites. Copyright © 2012 Society of Chemical Industry