Lab and field screening of 5 selected passive samplers for the measurement of VOC fluxes in groundwater

Abstract

The prospects and limitations of direct flux measurement of volatile organic compounds in groundwater with 5 selected passive samplers, currently available or self-constructible, are screened in a series of lab and field experiments. The selection of the 5 samplers for the practical experiments is based on the review of current passive samplers for the measurement of organic contaminants in water (Verreydt et al., 2010). The MESCO sampler and ceramic dosimeter were subjected to a batch lab screening experiment, while the passive flux meter, the sorbi sampler, the passive diffusion bag sampler and the ceramic dosimeter were installed in a monitoring well at a field site. The passive flux meter has proven to be the only passive sampler which effectively determines VOC mass fluxes. The ceramic dosimeter produced time- averaged concentration data comparable to traditional sampling data and can be used for long-term monitoring. The sorbi sampler also produced results which are more or less similar to traditional sampling data, but is not eligible for a long-term practice. The passive diffusion bag sampler has shown to be a reliable equilibrium sampler, but is not suitable for the determination of mass fluxes. The MESCO sampler has the poorest physical robustness and is therefore not suitable for long-term application in a groundwater monitoring well.