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Prediction of polycyclic aromatic hydrocarbon biodegradation in contaminated soils using an aqueous hydroxypropyl-beta-cyclodextrin extraction technique.

Research output: Contribution to Journal/MagazineJournal articlepeer-review

<mark>Journal publication date</mark>06/2005
<mark>Journal</mark>Environmental Toxicology and Chemistry
Issue number6
Number of pages6
Pages (from-to)1325-1330
Publication StatusPublished
<mark>Original language</mark>English


This study investigated the use of an aqueous hydroxypropyl-p-cyclodextrin (HPCD) shake extraction to predict the degree of microbial degradation of polycyclic aromatic hydrocarbons (PAHs) in soils. Three different aged PAH-contaminated soils were studied: A soil from a former coke works (CW) and two artificially contaminated soils (ACI and AC2). First, the catabolic activity of the indigenous soil microflora was assessed with C-14-respirometry, using a range of C-14- labeled aromatic compounds. Extensive mineralization of several compounds occurred in the CW and the AC2 soils, suggesting that both soils contained catabolically active microorganisms. No significant mineralization occurred in the ACI soil, implying that either it did not contain an indigenous PAH-degrading microbial population or that degradation, but not mineralization, occurred. The soils then were subjected to three sets of analyses: dichloromethane (DCM) soxhlet extraction, six-week biodegradation assay followed by DCM extraction, and extraction with HPCD followed by DCM extraction. A general decrease in PAHs present in the soils occurred after the biodegradation assay. In the CW and the AC1 soils, strong correlations were observed between the amount of PAHs biodegraded and the fraction of PAHs removed from the soils using the HPCD extraction. However, the AC2 soil showed a more modest correlation between the biodegradable fraction and the HPCD extractable fraction, with the HPCD extraction slightly underestimating the extent of PAH biodegradation. The results of this study indicated that an aqueous HPCD extraction may be a useful tool in assessing the microbial availability of aged contaminant mixtures in soils, although further validation is required.