Record Details
Field | Value |
---|---|
Title | Two studies concerning rare earth elements : I. Rare earth DTPA complexes as estuarine hydrological tracers : II. Rare earth elemental concentrations in some Pacific Northwest rivers |
Names |
Keasler, Kenneth M.
(creator) Loveland, Walter D. (advisor) |
Date Issued | 1983-06-30 (iso8601) |
Note | Graduation date: 1984 |
Abstract | Two studies were conducted involving rare earth elements. In the first study, the use of rare earth diethylenetriaminepentaacetic acid (DTPA) complexes as stable actiable tracers, a method of stable-isotope tracing with post-sampling neutron activation analysis, was explored. The persistence of rare earth DTPA complexes in estuarine waters was measured in simulated laboratory studies and in two field studies conducted in the South Shore Marina in Newport, Oregon. The ability to use more than one rare earth DTPA tracer simultaneously in a multitracing experiment was also tested in one field experiment. In the second study, theoretical calculations, laboratory experiments, and field experiments were used to study the solubility of the rare earth elements in river water. The field experiments consisted of measuring the soluble rare earth elemental concentrations for seven Pacific Northwest rivers (Columbia, Fraser, Klamath, Mary's, Rougue, Sacramento, and Willamette) using radiochemical neutron activation analyses. The laboratory experiments consisted of measuring the soluble rare earth elemental concentrations in a mixture (sediments and water) from the Columbia or Willamette River as the pH was changed from 6 to 8. Also, the absorption of Tm on Willamette River sediments was studied. The theoretical calculations of the solubility of the lanthanum and europium in river water were based upon the solubility of the rare earth phosphate and the speciation of the rare earth elements in rivers. Results of these calculations, using measured field data, were compared to the measured lanthanum and europium concentrations in the river Aare. The results of these studies are consistent with the interpretation that the soluble rare earth elemental concentrations in river water are controlled by the solubility of the rare earth phosphate and the speciation of the rare earth elements with most of the soluble rare earth elements associated with humic substances. |
Genre | Thesis/Dissertation |
Topic | Earths, Rare |
Identifier | http://hdl.handle.net/1957/41191 |