Trace elements and radionuclides in the Connecticut River and Amazon River estuary
The Connecticut River, its estuary and the Amazon River plume were studied to elucidate processes which control the flux of nuclides to the sea. Major ions (Ca, Mg, Na, Cl, Bicarbonate) and selected trace elements (Ra, Ba, Cu, Si) are introduced to the Connecticut River in proportion to the total dissolved load of various groundwaters. Si, Ra, and Ba are subject to removal from solution by seasonal diatom productivity; whereas the other groundwater-derived elements are found in proportion to TDS both time and space. These nuclides are released in the estuary when a portion of the Ra, Ba, and Si in riverine biogenic detritus is trapped in salt marshes and coves bordering the estuary where it redissolves and is exported to the main river channel at ebb tide. In the Amazon River estuary, the Ra and Ba are released in mid-salinity waters. Ra and Ba together with Si are subsequently removed by diatom productivity as reflected in increased Ra and Ba in the suspended particles and depleted dissolved nuclide concentrations in samples from the high productivity zone. In both the Connecticut River system and the Amazon River plume, Cu behaves conservatively; whereas the fates of Fe and Al are linked to soil-derived humic acids. Trace elements in Amazon plume sediments are found simply in proportion to the percentage of fine-grained size materials, despite low Th-228/Ra-228 mean residence times in the plume and the presence of Cs-137 in the sediment column. Estimates of the total flux of nuclides to the oceans can best be calculated on a mass balance basis using groundwater inputs. Unless significant repositories for nuclides exist in the river-estuarine system, the groundwater flux of dissolved nuclides is net flux to the ocean despite the reactions which occur in both rivers and estuaries.
- Research Organization:
- Yale Univ., New Haven, CT (USA)
- OSTI ID:
- 5128568
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
AMAZON RIVER
GEOCHEMISTRY
BARIUM
ENVIRONMENTAL TRANSPORT
CALCIUM COMPOUNDS
RADIONUCLIDE MIGRATION
CARBON COMPOUNDS
CESIUM 137
CHLORINE COMPOUNDS
CONNECTICUT RIVER
COPPER
MAGNESIUM COMPOUNDS
RADIUM 228
SILICON COMPOUNDS
SODIUM COMPOUNDS
THORIUM 228
DIATOMS
ESTUARIES
EXPERIMENTAL DATA
GROUND WATER
HUMIC ACIDS
MASS BALANCE
SEAS
SEDIMENTS
ACTINIDE ISOTOPES
ACTINIDE NUCLEI
ALGAE
ALKALI METAL COMPOUNDS
ALKALI METAL ISOTOPES
ALKALINE EARTH ISOTOPES
ALKALINE EARTH METAL COMPOUNDS
ALKALINE EARTH METALS
ALPHA DECAY RADIOISOTOPES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CESIUM ISOTOPES
CHEMISTRY
DATA
ELEMENTS
EVEN-EVEN NUCLEI
HALOGEN COMPOUNDS
HEAVY NUCLEI
HYDROGEN COMPOUNDS
INFORMATION
ISOTOPES
MASS TRANSFER
METALS
NUCLEI
NUMERICAL DATA
ODD-EVEN NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
PLANTS
RADIOISOTOPES
RADIUM ISOTOPES
RIVERS
STREAMS
SURFACE WATERS
THORIUM ISOTOPES
TRANSITION ELEMENTS
WATER
YEARS LIVING RADIOISOTOPES
520200* - Environment
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520300 - Environment
Aquatic- Radioactive Materials Monitoring & Transport- (1989)