Comparison of sampling techniques and evaluation of semipermeable membranedevices (SPMDs) for monitoring polynuclear aromatic hydrocarbons (PAHs) ingroundwater
Ke. Gustavson et Jm. Harkin, Comparison of sampling techniques and evaluation of semipermeable membranedevices (SPMDs) for monitoring polynuclear aromatic hydrocarbons (PAHs) ingroundwater, ENV SCI TEC, 34(20), 2000, pp. 4445-4451
Citations number
27
Categorie Soggetti
Environment/Ecology,"Environmental Engineering & Energy
Groundwater was sampled at the site of a former manufactured-gas plant usin
g three conventional methods (bailing, low-flow, and bailing with filtering
) and longterm in-situ samplers (semipermeable membrane devices [SPMDs]). S
amples from each technique were analyzed for polynuclear aromatic hydrocarb
ons (PAHs) and total suspended solids (conventional methods only) to determ
ine the effect of sampling procedure on PAH concentrations. In general, amo
ng the conventional techniques, bailing indicated the highest PAH concentra
tions, and bailing/filtering the lowest, with low-flow sampling in between.
High-molecular-weight PAHs were most prevalent in bailed samples and most
impacted by filtering, suggesting these species are particle-associated. SP
MD results corroborated this finding. SPMDs performed well in this study; S
PMD-derived PAH concentrations in the groundwater were similar to values ob
tained by the conventional techniques. Furthermore, they allowed detection
of some PAHs not detected by conventional approaches in wells with low leve
ls of contamination. An alternative method to the traditional equations for
estimating aqueous contaminant concentrations from SPMDs is proposed. This
method may be more appropriate in groundwater where low flows prevail. Ove
rall, this study suggests that SPMDs have high potential for use in groundw
ater monitoring, producing results consistent with conventional grab-sampli
ng techniques, providing enhanced sensitivity integrated over extended time
periods, and facilitating accurate determinations of truly dissolved PAH c
oncentrations.