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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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A Comparison of the Solubility Products of Layered Me(II)–Al(III) Hydroxides Based on Sorption Studies with Ni(II), Zn(II), Co(II), Fe(II), and Mn(II)
The precipitation of mixed metal–aluminum-layered double hydroxides (Me(II)–Al(III)-LDH)) may be an important control of the solubility of Mn(II), Fe(II), Ni(II), Zn(II), and Co(II) in soils, but assessment of this process is hindered by a lack of thermodynamic data. Here, we determined the solubility products (Ksp) of the Me(II)–Al(III)-LDHs formed by these metals based on long-term Me(II)–γAl2O3 sorption studies complemented with X-ray absorption spectroscopy (XAS) measurements. The LDH phases had the chemical formula Me(II)2/3Al1/3(OH)2Cl1/3. Solubility products were derived as Ksp = (Me2+)aq2/3(Al3+)aq1/3(OH−)aq2(Cl−)aq1/3, where brackets represent aqueous activity values determined from the equilibrium solution chemistry of the sorption samples. The Ksps are metal-dependent, with values increasing by two orders of magnitude in the order Ni(II) < Zn(II) < Co(II) < Fe(II) < Mn(II). Comparison to the solubility of β-Me(OH)2 suggests considerable thermodynamic preference of Me(II)–Al(III)-LDH over β-Me(OH)2 in soil environments and reveals a linear relation between the log-transformed Ksp values of Me(II)–Al(III)-LDH and β-Me(OH)2. Solubility plots suggest that Ni(II)–, Zn(II)–, and Co(II)–Al(III)-LDH may form in metal-polluted soils. Fe(II)–Al(III)-LDH may occur in riparian soils undergoing reduction, but precipitation of Mn(II)–Al(III)-LDH appears unlikely as it requires [Mn2+]aq much higher than commonly encountered in reducing soils. Additional thermodynamic and field studies are needed to further assess the importance of Me(II)–Al(III)-LDHs in soils and related geochemical systems.
Sorption-enhanced synthetic natural gas (SNG) production from syngas: A novel process combining CO methanation, water-gas shift, and CO2 capture
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Initial test performance of a closed-cycle continuous hydrogen sorption cooler, the Planck sorption breadboard cooler
JPL is developing a continuous hydrogen sorption cryocooler for the ESA Planck mission, which will measure the anisotropy in the cosmic microwave background.
Iodine Immobilization by Materials through Sorption and Redox-Driven Processes: A Literature Review
Radioiodine-129 (129I) in the subsurface is mobile and limited information is available on treatment technologies. Scientific literature was reviewed to compile information on materials that could potentially be used to immobilize 129I through sorption and redox-driven processes, with an emphasis on ex-situ processes. Candidate materials to immobilize 129I include iron minerals, sulfur-based materials, silver-based materials, bismuth-based materials, ion exchange resins, activated carbon, modified clays, and tailored materials (metal organic frameworks (MOFS), layered double hydroxides (LDHs) and aerogels). Where available, compiled information includes material performance in terms of (i) capacity for 129I uptake; (ii) long-term performance (i.e., solubility of a precipitated phase); (iii) technology maturity; (iv) cost; (v) available quantity; (vi) environmental impact; (vii) ability to emplace the technology for in situ use at the field-scale; and (viii) ex situ treatment (for media extracted from the subsurface or secondary waste streams). Because it can be difficult to compare materials due to differences in experimental conditions applied in the literature, Part II of this review describes results of laboratory studies for selected materials using a standardized batch loading test.
Moisture sorption characteristics and modeling of energy sorghum (Sorghum bicolor (L.) Moench)
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Actinide Sorption in a Dolomite Rock System: Evaluating the Degree of Conservatism in Kd Ranges Used in Performance Assessment Models
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Influence of Hydronium Ions in Zeolites on Sorption
In presence of sufficient concentrations of water, stable hydrated hydronium ions are formed in inorganic solid acids such as zeolites. In their presence larger organic molecules can only adsorb in the pore volume not occupied by hydronium ions. In consequence, the available pore volume decreases proportionally to their concentrations. The higher charge density (the increasing ionic strength) induced by increasing hydronium ion concentration in zeolite crystalline induces higher activity coefficients of adsorbed substrates, weakening the interactions between the organic part of the molecules, favoring instead interactions with polar groups. The insight allows linking a collective property such as hydrophilicity and hydrophobicity of zeolites to specific interactions on the molecular level.
Surface complexation modeling of proton and metal sorption onto graphene oxide
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Searching for the nano effect in Cu-HCF (II) particles to improve Cs sorption efficiency: Highlighting the use of intrinsic magnetism
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Water vapor sorption on Marcellus shale: measurement, modeling and thermodynamic analysis
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Role of nano-goethite in controlling U(VI) sorption-desorption in subsurface soil
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Evaluation of hydrogen sorption and permeation parameters in liquid metal membranes via Sieverts' apparatus
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An X-ray absorption fine structure spectroscopy study of metal sorption to graphene oxide
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