Publication Date:
2017-04-04
Description:
A new method for extracting dissolved gases in natural waters has been developed and tested, both in the laboratory and in the field. The sampling device consists of a polytetrafluroethylene (PTFE) tube (waterproof and gas permeable) sealed at one end and connected to a glass sample holder at the other end.
The device is pre-evacuated and subsequently dipped in water, where the dissolved gases permeate through the PTFE tube until the pressure inside the system reaches equilibrium. A theoretical model describing the time variation in partial gas pressure inside a sampling device has been elaborated, combining the mass
balance and ‘‘Solution-Diffusion Model’’ which describes the gas permeation process through a PTFE membrane). This theoretical model was used to predict the temporal evolution of the partial pressure of each gas species in the sampling device. The model was validated by numerous laboratory tests. The method was applied to the groundwater of Vulcano Island (southern Italy). The results suggest that the new sampling device could easily extract the dissolved gases from water in order to determine their chemical
and isotopic composition.
Description:
- European Social Fund.
Description:
Published
Description:
Q09005
Description:
partially_open
Keywords:
dissolved gases
;
helium isotope
;
PTFE membrane
;
Vulcano Island
;
03. Hydrosphere::03.02. Hydrology::03.02.04. Measurements and monitoring
;
03. Hydrosphere::03.02. Hydrology::03.02.07. Instruments and techniques
;
04. Solid Earth::04.04. Geology::04.04.11. Instruments and techniques
;
04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry
;
04. Solid Earth::04.06. Seismology::04.06.08. Volcano seismology
;
04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring
;
04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
Format:
503 bytes
Format:
446781 bytes
Format:
text/html
Format:
application/pdf
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