This work examines the addition of both fungal inoculum and
composted green waste to a PAH-contaminated sawmill soil in two
environments: a laboratory and a field scale. The aged creosote
contaminated soil, used in both treatment scales, contained
considerable amounts of fluoranthene (35% of 16 PAHs) and pyrene
(18% of 16 PAHs), which both contain four benzene rings. Even
some five- to six-ring PAHs were present and the total amount of 16
PAHs (listed by the United States Environmental Protection Agency)
was high (6000 mg kg1
). We studied the capability of selected
ligninolytic fungi to grow in the soil, produce extracellular
oxidizing enzymes, and degrade PAH compounds. The addition of
composted green waste improved the structure of soil for better
aeration and water holding capacity, and provided organic matter
as a carbon and energy source for fungi (Semple et al., 2001). To
determine the role of bacterial PAH degradation in the treatments,
we quantified PAH degradation genes by quantitative PCR.
Furthermore, to predict the bioaccessible fraction of PAHs in soil,
supercritical fluid extraction (SFE) was used (Cajthaml and
Sasek,
2005). The biodegradation results were compared with the bioaccessible
fraction. Since some of the metabolites formed during
bioremediation of the PAH compounds might be more toxic than
the parent compounds (Lundstedt et al., 2007), the soil was also
tested for ecotoxicity before and after the treatment.
This work examines the addition of both fungal inoculum andcomposted green waste to a PAH-contaminated sawmill soil in twoenvironments: a laboratory and a field scale. The aged creosotecontaminated soil, used in both treatment scales, containedconsiderable amounts of fluoranthene (35% of 16 PAHs) and pyrene(18% of 16 PAHs), which both contain four benzene rings. Evensome five- to six-ring PAHs were present and the total amount of 16PAHs (listed by the United States Environmental Protection Agency)was high (6000 mg kg1). We studied the capability of selectedligninolytic fungi to grow in the soil, produce extracellularoxidizing enzymes, and degrade PAH compounds. The addition ofcomposted green waste improved the structure of soil for betteraeration and water holding capacity, and provided organic matteras a carbon and energy source for fungi (Semple et al., 2001). Todetermine the role of bacterial PAH degradation in the treatments,we quantified PAH degradation genes by quantitative PCR.Furthermore, to predict the bioaccessible fraction of PAHs in soil,supercritical fluid extraction (SFE) was used (Cajthaml andSasek,2005). The biodegradation results were compared with the bioaccessiblefraction. Since some of the metabolites formed duringbioremediation of the PAH compounds might be more toxic thanthe parent compounds (Lundstedt et al., 2007), the soil was alsotested for ecotoxicity before and after the treatment.
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