The Pourbaix diagrams (potential-pH diagrams) for copper at 25 to 300°C have been revised. Extrapolation of thermochemical data to elevated temperatures has been performed with the revised model of Helgeson-Kirkham-Flowers, which also allows uncharged aqueous complexes, such as CuOH(aq) and Cu(OH)2(aq), to be handled. Calculated high temperature thermodynamic data have been fitted against experimental data at elevated temperature. The hydrolysis of copper(I) and (II) is included with two and four hydroxide complexes, respectively. The Pourbaix diagrams show that the oxides (Cu20(cr) and CuO(cr)) are stable at 25 to 200°C at 106 mol kg_L of dissolved species, and at 300°C only CuO is stable. The oxides are stable at 25°C at i0-mol kg', but at 100 to 300°C no solid compound is stable.

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A comprehensive literature review of thermodynamic data for compounds and complexes of actinides with oxalate, citrate, ethylenediaminetetraacetate (edta) and a-isosaccharinate has been carried out within the scope of the Thermodynamic Data Base project of the Organisation for Economic Co-operation and Development e Nuclear Energy Agency (OECD/NEA). Reliable values could be selected mainly for Am(III), Np(V) and U(VI) complexes, whereas serious data gaps were found for the tetravalent actinides. The redox states U(III), U(V), Pu(V), Am(V), Np(VI), Pu(VI) and Am(VI) are unstable in the presence of the selected organic ligands. Missing or unreliable data in these unstable redox states are of no importance from the viewpoint of application in environmental modelling studies. To cite this article: W.

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Within the scope of the OECD Nuclear Energy Agency (NEA) Thermochemical Data Base Project (TDB) a comprehensive review of selected organic ligands has been carried out by the authors. The selected ligands are oxalate, citrate, ethylenediaminetetraacetate (edta) and α-isosaccharinate (isa), and the elements considered in the review are U, Np, Pu, Am, Tc, Ni, Se and Zr, as well as the necessary basic data concerning protonation of the ligands and interactions with the major competing elements Na, K, Mg and Ca. This review on organic ligands showed that the pragmatic ionic strength correction procedure, the Specific ion Interaction Theory (SIT), chosen as the default method for all NEA TDB reviews, can be applied successfully also to organic ligands. The SIT interaction parameters derived from ligand protonation data for different media, e.g. NaCl and KCl, pass the consistency test when applied to other systems evaluated in the organics review, e.g. solubility data. Hence, the thermodynamic constants selected in this NEA TDB organics review can be used with some confidence in real world applications, provided that SIT is used in the speciation calculations.