The radiolytic changes in oxidation state for solutions of initially Np(V) and/or Np(VI) were investigated by gamma-irradiation in conjunction with UV/Vis spectroscopy of the aqueous phase. Samples were irradiated in varying concentrations of nitric acid, and with or without the presence of 30 % TBP in dodecane. At short irradiation...
Aqueous complexation of Th(IV), U(IV), Np(IV), Pu(III/IV), and Ce(III/IV) with DTPA was studied by potentiometry, absorption spectrophotometry, and cyclic voltammetry at 1 M ionic strength and 25 °C. The stability constants for the 1:1 complex of each trivalent and tetravalent metal were calculated. From the potentiometric data, we report stability...
Waste products from industry have often been disposed in
landfills without regard for any beneficial uses of the product in
agricultural production. This research was conducted to determine
the effect of a refractory metal processing waste product on (a) soil
chemical and physical properties, (b) perennial ryegrass forage
quality and...
The need for field and laboratory studies of the physical and
chemical behavior of environmentally significant organic molecules often
poses problems because of the toxicity of the chemical and the difficulty
of detecting it at environmentally significant concentrations.
Two dysprosium tracers, dysprosium (III) trisacetylacetonate trihydrate
and dysprosium(III) trisdibenzoylmethane monohydrate, were...
Two related techniques, based upon ion-exchange solid phase extraction, have been
developed for the determination of arsenic speciation. The inorganic arsenic species
arsenite (As(III)) and arsenate (As(V)) are separated by anion-exchange and detected with
graphite furnace atomic absorption spectrophotometry (GFAAS) with a nickel matrix
modifier. The first separation technique, which...
The photodebromination of selected bromoarenes has been studied at 300 nm
to determine the the possible mechanistic pathways leading to product.
Irradiation of 4-bromobiphenyl (BpBr) at this wavelength leads to the product
biphenyl. The quantum yield of intersystem crossing (0.98) and quenching
studies with cis-1 ,3-pentadiene suggest that the reaction...
A tracer method utilizing stable activable tracers (involving rare earth nuclides with short-lived t[subscript 1/2] < 1 day} activation products) for tracing fluid bound substances in fresh water is explored. Simulated laboratory studies showed these tracers (Dy and in) when chelated with diethylenetriamine2entaacetic acid a7i1W to be stable ( <20%)...