Passive Water-sampling Device: Comparison of Adsorption Efficiencies in Accordance with Adsorbent Types and Application to the Water Environment

A Passive water-sampling device is highly complementary to grab (spot) water sampling in environmental analysis. In particular, semipermeable membrane devices (SPMDs) are well-established biomimetic samplers that have proved to be useful for estimating the bioavailable water concentrations of hydrophobic micropollutants. The general performance and applicability of SPMDs have been verified in previous studies, and triolein containing-SPMDs for collecting hydrophobic micropollutants, such as polycyclic aromatic hydrocarbons (PAHs), are commercially available in a device package from EST-lab, USA. However, the adsorbent itself is a disposable item after one-time passive sampling, so a more cost-effective adsorbent is required. In terms of cost and efficiency, the adsorption efficiency of commercial triolein ($20/1 mL) adsorbent was compared with those of two kinds of alternative adsorbents, octanol ($0.1/1 mL) and olive oil ($0.03/ mL) through on-site field application. It was found that olive oil might be a highly cost-effective adsorbent for collecting hydrophobic contaminants, such as PAHs rather than triolein and octanol, if a biological assessment, such as yeast estrogen screen, is not considered. Various micropollutants, such as aliphatic and aromatic hydrocarbons and synthetic musks, were detected in on-site samples collected by using an SPMD. Moreover, a significant increase of these micropollutant concentrations was found at discharge points of the effluents of sewage treatment plants.