Equilibrium studies of beryllium complexes

Vanni, Adriano; Gennaro, Maria Carla; Ostacoli, Giorgio

doi:10.1016/0022-1902(75)80788-3

Cited by 15 publications

(1 citation statement)

References 17 publications

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“…This results in an amphoteric behaviour involving the formation of positively-and negatively-charged hydrolysis species. Several solubility and potentiometric studies previously investigated the solubility and hydrolysis of beryllium in acidic to near-neutral pH conditions, deriving thermodynamic data for the hydrolysis species Be n (OH) m 2n-m , with (n,m) = (1,1), (1,2), (2,1), (3,3), (5,6) and (6,8) (Mattock, 1954;Gilbert and Garrett, 1956;Kakihana and Sillen, 1956;Schindler and Garett, 1960;Carell and Olin, 1961;Schwarzenbach, 1962;Hietanen and Sillen, 1964;Bertin et al, 1967;Mesmer and Baes, 1967;Ohtaki, 1967;Ohtaki and Kato, 1967;Lanza and Carpéni, 1968;Pâris and Gregoire, 1968;Schwarzenbach and Wenger, 1969;Kakihana and Maeda, 1970;Tsukuda et al, 1975;Vanni et al, 1975;Baes and Mesmer, 1976;Bruno et al, 1987b;Bruno, 1987;Chinea et al, 1997;Brown and Ekberg, 2016). A significantly scarcer number of studies investigated the hydrolysis of Be(II) in alkaline to hyperalkaline conditions (Gilbert and Garrett, 1956;Green and Alexander, 1965;Bruno et al, 1987a), where the hydrolysis species Be(OH) 3 and Be(OH) 4 2are expected to prevail.…”

Section: Introductionmentioning

confidence: 99%

Beryllium solubility and hydrolysis in dilute to concentrated CaCl2 solutions: thermodynamic description in cementitious systems

Çevirim-Papaioannou,

Androniuk,

Miron

et al. 2023

Front. Nucl. Eng.

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The solubility and hydrolysis of Be(II) was investigated from undersaturation conditions in alkaline, dilute to concentrated CaCl2 solutions (0.05–3.5 M). Experiments were performed with α-Be(OH)2(cr) under Ar atmosphere at T = (22 ± 2)°C. Aqueous Be speciation was further investigated by means of molecular dynamics (MD) calculations. For the most diluted CaCl2 systems (0.05 and 0.25 M), a solubility minimum is observed at pHm ≈ 9.5 {with [Be(II)] ≈ 10−7 M}, consistent with solubility data previously reported in NaCl and KCl solutions. Above this pHm, and at higher CaCl2 concentrations, a steep increase in the solubility with a slope of ∼ +2 is observed, hinting towards the predominance of the moiety [Be(OH)42–] in the aqueous phase. In NaCl and KCl systems, this hydrolysis species prevails only above pHm ∼ 13, thus supporting the formation of ternary complex/es Ca–Be(II)–OH(aq) in CaCl2 solutions. The analysis of solubility data in combination with MD calculations underpin the key role of the complex Ca2[Be(OH)4]2+ in alkaline to hyperalkaline systems containing Ca. In combination with our previous work in NaCl–NaOH and KCl–KOH systems, complete chemical, thermodynamic and (SIT) activity models are derived for the first time for the system Be2+–Ca2+–Na+–K+–H+–Cl––OH––H2O(l). This model provides an accurate and robust tool for the evaluation of Be(II) solubility and speciation in a diversity of geochemical conditions, including source term calculations of beryllium in the context of repositories for nuclear waste disposal with a high cement inventory.

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