TY - JOUR
T1 - Low accessibility and chemical activity of PAHs restrict bioremediation and risk of exposure in a manufactured gas plant soil
AU - Reichenberg, Fredrik
AU - Karlson, Ulrich Gosewinkel
AU - Gustafsson, Örjan
AU - Long, Sara M.
AU - Pritchard, Parmely H.
AU - Mayer, Philipp
PY - 2010
Y1 - 2010
N2 - Composting of manufactured gas plant soil by a commercial enterprise had removed most of its polycyclic aromatic hydrocarbons (PAHs), but concentrations remained above regulatory threshold levels. Several amendments and treatments were first tested to restart the PAH degradation, albeit with little success. The working hypothesis was then that PAHs were "stuck" due to strong sorption to black carbon. Accessibility was measured with cyclodextrin extractions and on average only 4% of the PAHs were accessible. Chemical activity of the PAHs was measured by equilibrium sampling, which confirmed a low exposure level. These results are consistent with strong sorption to black carbon (BC), which constituted 59% of the total organic carbon. Composting failed to remove the PAHs, but it succeeded to minimize PAH accessibility and chemical activity. This adds to accumulating evidence that current regulatory thresholds based on bulk concentrations are questionable and alternative approaches probing actual risk should be considered. (C) 2010 Elsevier Ltd. All rights reserved.
AB - Composting of manufactured gas plant soil by a commercial enterprise had removed most of its polycyclic aromatic hydrocarbons (PAHs), but concentrations remained above regulatory threshold levels. Several amendments and treatments were first tested to restart the PAH degradation, albeit with little success. The working hypothesis was then that PAHs were "stuck" due to strong sorption to black carbon. Accessibility was measured with cyclodextrin extractions and on average only 4% of the PAHs were accessible. Chemical activity of the PAHs was measured by equilibrium sampling, which confirmed a low exposure level. These results are consistent with strong sorption to black carbon (BC), which constituted 59% of the total organic carbon. Composting failed to remove the PAHs, but it succeeded to minimize PAH accessibility and chemical activity. This adds to accumulating evidence that current regulatory thresholds based on bulk concentrations are questionable and alternative approaches probing actual risk should be considered. (C) 2010 Elsevier Ltd. All rights reserved.
KW - Soot
KW - Biodegradation
KW - Hydrophobic organic pollutants
KW - Freely dissolved concentrations
KW - Persistence
U2 - 10.1016/j.envpol.2010.01.031
DO - 10.1016/j.envpol.2010.01.031
M3 - Journal article
C2 - 20202727
SN - 0269-7491
VL - 158
SP - 1214
EP - 1220
JO - Environmental Pollution
JF - Environmental Pollution
IS - 5
ER -