The evaluation of the pore-size distribution (PSD) of natural and modified mesoporous zeolites, i.e., clinoptilolites is presented. We demonstrate the SEM results showing that the pores of fracture-type from 25-50 nm to 100 nm in size between clinoptilolite grains, as well as pores between crystal aggregates up to 500 nm in size are present in the studied material. The detailed distribution of ...

Zeolites are widely applied as solid acid catalysts in various technological processes. In this work we have computationally investigated how catalytic reactivity scales with acidity for a range of zeolites with different topologies and chemical compositions. We found that straightforward correlations are limited to zeolites with the same topology. The adsorption energies of bases such as carbo...

Parameters from single-component isotherm models were used in multicomponent isotherm models to predict the aqueous phase sorption of trichloroethylene (TCE) in the presence of tetrachloroethylene (PCE) in four zeolites, Tenax, and three natural solids. The Langmuir, the Polanyi-Dubinin, and the Freundlich or the Langmuir-Freundlich isotherm models were used to simulate single-component sorptio...

O NE OF THE methods currently being investigated for the regenerable removal of carbon dioxide from space vehicle atmospheres involves its adsorption on synthetic zeolites. These materials, known commercially as "molecular sieves" (Linde Company) or "microtraps" (Davison Chemical Company) are crystalline alumino silicates of alkali and alkaline earth metals. Synthetic zeolites being crystalline...

Ammoniacal nitrogen (ammonia and ammonium) in agricultural wastewaters can promote eutrophication of receiving waters and be potentially toxic to fish and other aquatic life. Zeolites, which are hydrated aluminum-silicate minerals, have an affinity for ammonium ions (NH4"") and are, therefore, potentially useful in removing this contaminant from wastewaters. The major objectives of this study w...

In this study, the adsorption behavior of natural (clinoptilolite) zeolites with respect to Co(2+), Cu(2+), Zn(2+), and Mn(2+) has been studied in order to consider its application to purity metal finishing wastewaters. The batch method has been employed, using metal concentrations in solution ranging from 100 to 400 mg/l. The percentage adsorption and distribution coefficients (K(d)) were dete...