Abstract
Membrane-extraction Ion Mobility Spectrometry (ME-IMS) is a feasible technique for the continuous monitoring of chlorinated hydrocarbons in water. This work studies theoretically the time-dependent characteristics of sampling and detection of trichloroethylene (TCE). The sampling is configured so that aqueous contaminants permeate through a hollow polydimethylsiloxane (PDMS) membrane and are carried away by a transport gas flowing through the membrane tube into IMS analyzer. The theoretical study is based on a two-dimensional transient fluid flow and mass transport model. The model describes the TCE mixing in the water, permeation through the membrane layer, and convective diffusion in the air flow inside membrane tube. The effect of various transport gas flow rates on temporal profiles of IMS signal intensity is investigated. The results show that fast time response and high transport yield can be achieved for ME-IMS by controlling the flow rate in the extraction membrane tube. These modeled time-response profiles are important for determining duty cycles of field-deployable sensors for monitoring chlorinated hydrocarbons in water.
Original language | English |
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Pages (from-to) | 65-71 |
Number of pages | 7 |
Journal | International Journal for Ion Mobility Spectrometry |
Volume | 13 |
Issue number | 2 |
DOIs | |
State | Published - 2010 |
Funding
Acknowledgment Modeling and experimental portions of research were sponsored by the Laboratory Directed Research and Development Program at Oak Ridge National Laboratory (ORNL) and the Strategic Environmental Research and Development Program (SERDP), respectively. ORNL is managed by UT-Battelle, LLC for the U.S. Department of Energy under Contract DE-AC05-00OR22725.
Keywords
- Chlorinated hydrocarbons
- Ion mobility spectrometry
- Membrane
- Modeling
- Permeation
- Transport phenomena