Treatment of produced water using walnut shell for 226Ra removal

Journal of Radioanalytical and Nuclear Chemistry - Sorption and desorption of 226Ra from produced water with oil production on walnut shell media were investigated using batch-type and column-type...     

Synthesis,radiochemical and biological characteristics of <Superscript>99m</Superscript>Tc-8-hydroxy-7-substituted quinoline complex: a novel agent for infection imaging

2,2′-[(8-hydroxyquinolin-7-yl)methylazanediyl]diacetic acid (HQMADA) was synthesized via reaction of 8-hydroxyquinoline with iminodiacetic acid in presence of paraformaldehyde with a yield of 27%. The obtained compound was well characterized via different analytical techniques. Labeling of the synthesized compound with technetium-99m in pertechnetate form (^99mTcO₄ ⁻) in the presence of stannous chloride dihydrate was carried out via chelation reaction. The reaction parameters that affect the labeling yield such as HQMADA concentration, stannous chloride dihydrate concentration, pH of the reaction mixture, and reaction time were studied to optimize the labeling conditions. Maximum radiochemical yield of ^99mTc-HQMADA complex (91.9%) was obtained by using 1.5 mg HQMADA, 50 μg SnCl₂·2H₂O, pH 8 and 30 min reaction time. Biodistribution studies in mice were carried out in experimentally induced infection in the left thigh using E. coli. ^99mTc-HQMADA complex showed higher uptake (T/NT = 5.5 ± 0.3) in the infectious lesion than the commercially available ^99mTc-ciprofloxacin (T/NT = 3.8 ± 0.8). Biodistribution studies for ^99mTc-HQMADA complex in Albino mice bearing septic and aseptic inflammation models showed that ^99mTc-HQMADA complex able to differentiate between septic and aseptic inflammation.     

Heteropolynuclear cobalt(II) and nickel(II) ethylenediaminetetraacetates in aqueous solutions of aminoethanoic acid

Complexation in the Co(II)?Ni(II)?aminoethanoic acid (HGly)?EDTA (H₄Edta) system was studied at different molar ratios of components by absorption spectrophotometry. The mathematical modeling of A = f(pH) curves was used to establish that bi-, tri-, and tetranuclear heteroligand complexes like [(CoGly)Edta(NiGly)]^2?, [(CoGly₂)Edta(NiGly₂)]^4?, [(CoGly₂)Edta(NiGly₂)₂]^4?, [(CoGly₂)₂Edta(NiGly₂)]^4?, and [(CoGly₂)₂Edta(NiGly₂)₂]^4?, whose accumulation fraction attained 80?100% at optimal pH values, were formed depending on the ratio of reagents and the acidity of a medium. The formation equilibrium and total stability constants of these complexes were calculated, and a hypothesis about their structure was made.     

Spatial and vertical distributions of natural and anthropogenic radionuclides and cesium fractionation in sediments of the Var river and its tributaries (southeast France)

This paper reports results on the natural and anthropogenic radionuclides activity concentrations in sediments of the Var river and its tributaries. Natural (²³⁸U, ²³²Th and ⁴⁰K) and artificial (¹³⁷Cs) radionuclides activities were measured using high purity germanium detector. Measured activity concentrations differ widely; they depend on the pertinent environmental situation such as the presence of dams, and sediments type. Other factors controlling the distribution of the studied radioisotopes have been discussed. A sequential extraction method consisting of six operationally-defined fractions has been used for determining the geochemical partitioning of anthropogenic radionuclide ¹³⁷Cs in a 405–410 cm deep sediments collected in the lower valley of the Var river. This method corresponds to a modification of the three-stage sequential extraction procedure proposed by the Commission of the European Communities Bureau of Reference (BCR, now Standards, Measurements and Testing Program). Two steps with weak reagents, (fraction A: water; fraction B: nitric acid 0.001 M), were added before the first step of BCR (carbonate fraction) in order to better detect anthropogenic components. A total acid digestion of solid residues by microwave assisted was also added. The 6-steps extraction method was tested and validated by certified reference materials. ¹³⁷Cs was found mostly in the hydrosoluble fraction (20–24 %), oxide and hydroxide fraction (22–25 %) and in the residue (51–58 %), while ¹³³Cs was mostly found in the residual fraction (>97 %).