Publication Date:
2022-05-26
Description:
Two polypropylene cartridge types (Beta Pure and Hytrex II) were tested in the laboratory as adsorbers for in-situ collection of
dissolved Thorium-234 (234TH) in seawater. Using a uranyl nitrate tracer, we determined that a Mn02 impregnated 3.25-inch Hytrex
II cartridge with a flow rate of 8 liters/minute would collect 234TH with a greater than 60% effciency. The smaller size and
composition of the 3.25 inch Hytrex II cartridge enabled it to be pressed into a permanent 1-inch "puck" for direct gamma
counting. This protocol significantly reduced the handling between collection and counting. When field tested in the Gulf of Maine
as a large volume (〉500 liters) collector, the new adsorbers produced a greater than 80% collection effciency and a dissolved 234TH concentration which was consistent with independent samples collected at the same station and depth. These adsorbers were used
successfully for the in-situ collection of 234TH in large volumes of seawater during the 1992 NOAA and NSF sponsored JGOFS
EqPac program, with a mean collection efficiency of 0.79 +/- 9% (n=104 cartridge pairs).
Description:
Funding was provided by the National Oceanic and Atmospheric Administration
Offce of Global Programs under Contract OCE-920395200.
Keywords:
Thorium-234
;
Mn02 adsorber
;
seawater
;
Cape Hatteras (Ship) Cruise
;
Malcolm Baldridge (Ship) Cruise
;
Discoverer (Ship) Cruise
Repository Name:
Woods Hole Open Access Server
Type:
Technical Report
Format:
897958 bytes
Format:
application/pdf
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