Zeolites have found widespread applications as catalysts and separation media. A L present, all technologies exploiting these materials use the zeolite in powder composite form. The desire to translate the molecular sieving properties of zeolite powder composites into a membrane configuration has long been recognized. To prepare such a membrane, the crystals must grow in an interlockng fashion ...

The impact of nanopore diffusion on the performance of adsorption separation processes is reviewed. Zeolite membrane processes and kinetically selective cyclic adsorption processes depend for their selectivity on differences in intracrystalline diffusion rates so these processes are designed to operate under conditions of intracrystalline diffusion control. In contrast, the performance of equil...

The main goal of this work was to synthesize and evaluate the effect of dehydration temperature on the potential application of hydroxy sodalite zeolite membrane. Hydroxy sodalite zeolite membranes were synthesized via direct hydrothermal method onto a tubular alumina support without seeding in a hot air oven. The synthesized membranes were characterized by X-ray diffraction (XRD) and scanning ...

Adoption of new management techniques that improve soil water storage and soil N plant availability yet limit N leaching may help improve environmental quality. A benchtop study was conducted to determine the influence of a single urea fertilizer rate (224 kg N ha) applied with band or fully mixed zeolite (clinoptilolite) application rates (up to 90 Mg ha) on NH4-N and NO3-N concentrations in a...

Urban landfill leachate is a high strength wastewater characterized by high concentrations of recalcitrant organic compounds, ammonia and, increasingly, arsenic. The aims of this study were the review on membrane bioreactor, ion exchange and adsorption method for landfill leachate treatment. Membrane bioreactor (MBR) can be used for wastewater and landfill leachate treatment. The most important...

The effects of a sub-nanometer grain boundary in all-silica chabazite (CHA) zeolite membranes on their permeation properties were investigated by non-equilibrium molecular dynamics (NEMD). results indicated that at the total pressure 0.5 MPa, 298 K, CO2 selectivity toward CH4 drastically increased due to presence region inside membrane. This was consequence selective condensation boundary. calc...

microporous hydroxy-sodalite zeolite membranes with different morphologies were synthesized via secondary growth technique with vacuum seeding on tubular α-al2o3 supports at two different synthesis conditions (i.e. two different routes). microstructures of the synthesized membranes were characterized by x-ray diffraction (xrd), scanning electron microscope (sem) and single gas permeation using ...

Zeolite 4A, synthetic silicate, has been shown to exhibit diverse biological activities such as anti-cancer and anti-oxidant activity. In the present study, we report that the zeolite 4A may improve skin-whitening. We found that zeolite 4A inhibited melanin production in a dose-dependent manner, which has not cytotoxicity. Zeolite 4A also inhibited alpha-melanocyte-stimulating hormone (alpha-MS...

Temperature-dependent zeolite synthesis has revealed a unique surface morphology, surface area and pore size which influence the immobilization of urease on gold electrode supports for biosensor fabrication. XRD characterization has identified zeolite X (Na) at all crystallization temperatures tested. However, N₂ adsorption and desorption results showed a pore size and pore volume of zeolite X ...