Search Results

You are looking at 1 - 2 of 2 items for

  • Author or Editor: Concetta De Stefano x
  • Refine by Access: All Content x
Clear All Modify Search
Journal of Radioanalytical and Nuclear Chemistry
Authors: Concetta De Stefano, Antonio Gianguzza, Alberto Pettignano, Daniela Piazzese, and Silvio Sammartano

Abstract  

Stability data on the formation of dioxouranium(VI) species with polyacrylic (PAA) and fulvic acids (FA) are reported with the aim to define quantitatively the sequestering capacity of these high molecular weight synthetic and naturally occurring ligands toward uranium(VI), in aqueous solution. Investigations were carried out at t = 25 °C in NaCl medium at different ionic strengths and in absence of supporting electrolyte for uranyl–fulvate (
\documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $${{\text{UO}}_{2}}^{2+}$$ \end{document}
–FA) and uranyl–polyacrylate (
\documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $${{\text{UO}}_{ 2}}^{ 2+ }$$ \end{document}
–PAA, PAA MW 2 kDa) systems, respectively. The experimental data are consistent with the following speciation models for the two systems investigated: (i) UO2(FA1), UO2(FA1)(FA2), UO2(FA1)(FA2)(H) for
\documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $${{\text{UO}}_{ 2}}^{ 2+ }$$ \end{document}
–fulvate (where FA1 and FA2 represent the carboxylic and phenolic fractions, respectively, both present in the structure of FA), and (ii) UO2(PAA), UO2(PAA)(OH), (UO2)2(PAA)(OH)2 for
\documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $${{\text{UO}}_{ 2}}^{ 2+ }$$ \end{document}
–polyacrylate. By using the stability data obtained for all the complex species formed, the uranium(VI) sequestration by PAA and FA was expressed by the pL50 parameter [i.e. the −log(total ligand concentration) necessary to bind 50% of uranyl ion] at different pH values. A comparison between pL50 values of FA and PAA and some low molecular weight carboxylic ligands toward uranyl ion is also given.
Restricted access

Abstract  

The ancient mortars of the monastery of San Filippo di Fragalà in Frazzanò, the first Basilian-Norman center in Sicily, have been studied and classified by means of ICP, HPLC, TG-DTA, XRD and thin sections analysis. A new very simple method to evaluate the hydraulic properties of the mortars, based on the combination of analytical and thermogravimetric data, is also reported. The HPLC investigations indicate that the monastery is only partially involved in decay phenomena due to the action of soluble salts.

Restricted access