The general temperature range for THEREDA is currently limited to 0 to about 110°C. For the important electrolyte NaCl there are thermodynamic data available to 200°C and above. To cover this larger temperature range for the Pitzer coefficients, a refit of the temperature functions of Greenberg, J. P. and Møller, N. (Geochim. Cosmochim. Acta 53 (1989) 2503-2518) is presented. A corresponding function for the solubility constant of NaCl is deduced from IUPAC recommended data. The data set for NaCl, thus extended in its range of validity up to 200°C, is implemented in THEREDA.

Les sédiments urbains et résidus minier sont deux sources de pollution potentielle pour l’environnement et plus particulièrement les eaux de surfaces ou les eaux souterraines. L’altération chimique de ces interfaces solides par contact avec une source d’acidité ou d’alcalinité via l’air ou l’eau, est susceptible de se traduire par une dissolution des phases minérales et organiques et d’induire une mobilisation des éléments majeurs et traces métalliques. Ces mécanismes sont encore mal décrits et modélisés pour ce type de matrices très complexes. Cette thèse étudie donc le potentiel de mobilisation des éléments majeurs et traces métalliques de diverses interfaces carbonaté ou non carbonaté (pour l’étude du drainage minier acide et neutre contaminé). En supplément, des interfaces minérales pures ont été utilisées pour simuler en laboratoire des assemblages de phases et identifier les mécanismes croisés impliqués dans le drainage minier acide et neutre contaminé. Toutes ces matrices ont été soumises à des tests de capacité de neutralisation acido-basique (mise en contact avec une source de protons ou d’alcalinité), avec le suivi du pH (pouvoir tampon), de la conductivité et de la mobilisation élémentaire (majeurs et éléments traces métalliques). Les données expérimentales ont été modélisées avec le logiciel de spéciation géochimique PHREEQC. La combinaison des volets d’expérimentation et de modélisation, qui a très rarement été développé sur des interfaces solides aussi complexes, a permis l’identification (i) des réactions de dissolution des phases constitutives des interfaces polluées avec les réactions de sorption impliquées dans la mobilisation de leurs éléments majeurs et traces métalliques, (ii) de la spéciation des éléments majeurs et traces métalliques dans ces interfaces et dans les solutions en équilibre avec les phases solides. Ce travail de thèse permet donc d’aboutir à une méthodologie robuste, précise et réplicable permettant une caractérisation fine de la spéciation en phase liquide et solide des polluants métalliques dans les interfaces contaminées. Cette méthodologie constitue une base cruciale pour comprendre et prédire l’évolution des matières solides contaminées (sédiments urbains et déchets miniers) en fonction des différents modes de gestion : dépollution, valorisation et recyclage. / Urban sediments and mine tailings constitute two potential sources of pollution for the environment, especially surface water or groundwater. The chemical alteration of these solid matrices by contact with a source of acidity or alkalinity via air or water is likely to result in the dissolution of the mineral and organic phases and to induce the mobilization of majors and trace elements. These mechanisms are still poorly described and modeled for this type of very complex matrices. This thesis investigates potential for the mobilization of major and trace metals elements of various contaminated complex matrices, including an urban infiltration basin sediment and two carbonated and non-carbonated mining waste (for the study of contaminated acid mining drainage and contaminated neutral drainage). Besides, pure minerals were used to simulate phase mixture at the laboratory and identify the crossed mechanisms involved in contaminated acid and neutral mine drainage. All these matrices were subjected to acid-base neutralization capacity tests (solids put into contact with a source of protons or alkalinity), with monitoring of the pH (buffer capacity), the conductivity and the elemental release (major and trace metal elements). Experimental data were modeled with the PHREEQC geochemical speciation software. The combination of experimental and modeling approaches, which had very rarely been developed on such complex solid matrices, allowed the identification of (i) the dissolution reactions of the constitutive phases of the polluted matrices with the sorption reactions involved in the mobilization of their major and trace metal elements, (ii) the speciation of the major and trace metal elements in these matrices and in solution in equilibrium with the solid phases. This thesis, therefore, leads to a robust, precise and replicable methodology allowing a fine characterization of liquid and solid phase speciation of metallic pollutants in contaminated matrices. This methodology constitutes a crucial basis for understanding and predicting the evolution of contaminated solids (urban sediments and mining waste) according to different management methods: decontamination, recovery, and recycling.

In the ternary system CsCl – NaCl – H2O, at a temperature of 298.15 K, a double salt with the stoichiometric formula CsCl∙2NaCl∙2H2O(cr) is known to be formed. This double salt and the anhydrous CsCl(cr) are the end-members of a solid solution. For the pure double salt, the solubility constant was determined. The obtained value was applied to calculate the solubility diagram also of the quaternary system CsCl – NaCl – KCl – H2O and the quaternary-reciprocal system Cs+, Na+ || Cl−, SO42− – H2O. The solubility constant together with a solid solution between CsCl·2NaCl·2H2O(cr) and CsCl(cr) were implemented in THEREDA, which extends the applicability of the existing cesium dataset.

For the polythermal Pitzer dataset of the hexary system of oceanic salts (Na+, K+, Mg+2, Ca+2, Cl-, SO4-2 - H2O) including acids and hydroxides the data selection is documented in detail in the report “THEREDA - Thermodynamische Referenzdatenbasis” (Altmaier et al. 2011, https://www.grs.de/de/aktuelles/publikationen/grs-265-thereda-thermodynamische-referenzdatenbasis-abschlussbericht). The present short communication supplements this report by the numerical values of all temperature coefficients.

This report documents the selection of thermodynamic data for lead and lead compounds. Except for elemental lead, it is restricted to lead in the oxidation state +II (plumbous lead). Besides formation constants and, in part, enthalpies of formation and standard entropies, interaction coefficients for the correction of activity coefficients following the Pitzer formalism are provided. Aqueous complexes of lead with chloride, sulphate, and hydroxide are explicitly accounted for in the Pitzer model. Wherever possible, the validity of selected data is tested by recalculating experimental data. The presented data set is valid for 298.15K only.