In this work, we report a new hybrid nanomaterial based on the immobilization of 4-formyl benzo-9-crown-3 ether (FB9C3) onto the mesopores of MCM-41. First, the mesoporous molecular sieve MCM-41 was covalently grafted with 3-aminopropyl triethoxysilane to give aminopropyl modified MCM-41 (AmpMCM-41). Reaction of this material with FB9C3 afforded the B9C3-AmpMCM-41 hybrid nanomaterial. The prepa...

introduction conventional water treatment consist of unit processes include coagulation, flocculation, clarification, filtration and disinfection that goal is removal of turbidity, color and certain bacterial species. in filtration process flocculated substances that have not removed in pervious stage are sediment. filter media is often silica sand that removal mechanism is complex and consists...

the aim of the present work is to prepare an adsorption package to simulate adsorption / desorption operation for both single and multi-component systems in an isothermal condition by different mechanisms such as; local adsorption theory and mass transfer resistance (rigorous and approximated methods). different mass transfer resistance mechanisms of pore, solid and bidispersed diffusion, toget...

Silica aerogels are frequently employed as solid desiccants in enthalpy wheels for dehumidifying the supply stream in air-conditioning systems. These desiccant materials possess good moisture adsorption and desorption characteristics due to their porous structure. Analysis of adsorption and desorption isotherms is critical for performance characterization and is often performed to evaluate the ...

The aim of the present work is to prepare an adsorption package to simulate adsorption / desorption operation for both single and multi-component systems in an isothermal condition by different mechanisms such as; local adsorption theory and mass transfer resistance (rigorous and approximated methods). Different mass transfer resistance mechanisms of pore, solid and bidispersed diffusion, t...

The adsorption/absorption of hydrogen and the adsorption of carbon monoxide by niobium foils, at room temperature, was studied using thermal desorption spectroscopy. Two hydrogen desorption peaks were observed with a maximum at 404 and 471 K. The first hydrogen desorption peak is regarded as hydrogen desorbing from surface sites while the second peak, which represents desorption from surface si...

A series of CuBi co-doped mesoporous zeolite Beta (CuxBiy-mBeta) were prepared by a facile one-pot hydrothermal treatment approach and were characterized by XRD, N2 adsorption-desorption, TEM/SEM, XPS, H2-TPR, NH3-TPD and in situ DRIFTS. The catalysts CuxBiy-mBeta were applied to the removal of NOx by selective catalytic reduction with ammonia (NH3-SCR), especially the optimized Cu1Bi1-mBeta ac...

Monosulfuron-ester is a new, low rate, sulfonylurea herbicide that is being promoted for annual broadleaf and gramineal weed control; however, there is a lack of published information on its behavior in soils. The adsorption and desorption of monosulfuron-ester by seven type soils were measured using a batch equilibrium technique. The results showed that the Freundlich equation fitted its adsor...