Passive membrane sampler for assessing VOCs contamination in unsaturated and saturated media

Chenju Liang; Jheng-Shin Chang; Tzu-Wen Chen; Yuwen Hou

doi:10.1016/j.jhazmat.2020.123387

Passive membrane sampler for assessing VOCs contamination in unsaturated and saturated media

J Hazard Mater. 2021 Jan 5:401:123387. doi: 10.1016/j.jhazmat.2020.123387. Epub 2020 Jul 4.

Authors

Chenju Liang¹, Jheng-Shin Chang², Tzu-Wen Chen², Yuwen Hou²

Affiliations

¹ Department of Environmental Engineering, National Chung Hsing University, 145 Xingda Rd., South Dist., Taichung City, 402, Taiwan. Electronic address: cliang@nchu.edu.tw.
² Department of Environmental Engineering, National Chung Hsing University, 145 Xingda Rd., South Dist., Taichung City, 402, Taiwan.

PMID: 32763689
DOI: 10.1016/j.jhazmat.2020.123387

Abstract

Passive sampling (PS) is a method employed to detect volatile organic compounds in groundwater and soil gas. This study attempted to manufacture a polydimethylsiloxane (PDMS) dialysis passive sampler for potential application in detecting trichloroethylene (TCE) in aqueous and gaseous phases. The equilibrium time of the passive sampler was initially determined, followed by multilayer passive sampling in a three-dimensional sandbox to construct a tomography of TCE vapor spatial distribution in the vadose zone above the saturated water level. The results indicated that an equilibrium time period of >10 d was required in the aqueous phase containing TCE concentrations ranging from 3 to 25 mg L^-1, while an equilibrium time period of >12 d was necessary for TCE vapor concentrations ranging from 2.6-26 mg L^-1. Therefore, a 14 d of equilibrium time was suggested for application of this passive sampler in detecting vapor and aqueous phase TCE. After collection of the passive samples from the three-dimensional sandbox, a three dimensional visualization was created, and it was demonstrated to be a reasonable way to simulate a three dimensional TCE distribution. It was confirmed that the passive sampler developed in this study is effective for assessing TCE contamination in the subsurface.

Keywords: Chlorinated solvents; Passive sampler; Polydimethylsiloxane (PDMS); Soil gas survey; Unsaturated aquifer.

Publication types

Research Support, Non-U.S. Gov't