varieties of st. john’s wort (hypericum perforatum l.) native to iran possess the largest percentage of hypercin in their leaves and flowers. isotherm curves show the relationship between the relative humidity and moisture content of the plant at a constant temperature. it is essential to understand the isotherms curves for successful storage and drying of the plant. this study used adsorption ...

fertilizer plant waste carbon slurry has been investigated after some processing as an adsorbent for the removal of dyes and phenols using columns. the results show that the carbonaceous adsorbent prepared from carbon slurry being porous and having appreciable surface area (380 m2/g) can remove dyes both cationic (meldola blue, methylene blue, chrysoidine g, crystal violet) as well as anionic (...

In this research paper, an experimental breakthrough curve for citric acid in an adsorption recovery process was determined by an ion-exchange resin in 20, 35, 55 °C. Also, a mathematical model for breakthrough curve was presented. Among ion exchange resins that have been experienced, many weak and strong basic anionic resins are available such as, IRA-92, IRA-93, IRA-420 and IRA-458 and all of...

Dynamic modeling and simulation of fixed bed adsorption process was carried out by explaining the behavior of breakthrough curve parameter. Adsorption of sulfur compound, present in road fuel, has posed a great challenge. A model of fixed bed adsorption of benzothiophene from fuel was formulated with non-ideal plug flow behavior and considered velocity variation along a column. The model was so...

We present a thermodynamic model of adsorption-induced deformation of microporous carbons. The model represents the carbon structure as a macroscopically isotropic disordered three-dimensional medium composed of stacks of slit-shaped pores of different sizes embedded in an incompressible amorphous matrix. Adsorption stress in pores is calculated by means of Monte Carlo simulations. The proposed...

The kinetic behavior of a fixed-bed adsorber can be explained and the characteristic breakthrough curve of the adsorption phenomena can be obtained through mathematical models. In the earlier models, the kinetics is explained using a mathematical model that takes into account of external and internal masstransfer resistances with a nonideal plug flow behavior. The variation of fluid velocity al...

in this work, the adsorption of carbon dioxide from model flue gas on different adsorbents has been investigated. using simplified modeling, parameters such as the total mass transfer coefficient and the effective diffusivity have been determined. experiments were carried out in two sections: firstly, adsorption of pure carbon dioxide on different adsorbents was measured at pressures ranging fr...

application of granular activated carbon (gac) in adsorption process has been studied for the advanced treatment of municipal and industrial wastewater. because of entering poisonous compounds such as furfural, phenol and sulfides into the oily wastewater of tehran refinery, biological aeration basins of wastewater treatment unit may not have the desired performance of cod reduction. in this st...