Sharif Digital Repository

This paper presents a state of the art review of adsorption models for a new plant-based surfactant adsorption onto sandstone minerals. The adsorption data at both kinetic and equilibrium modes were obtained from batch experiments. Four adsorption kinetic models, five two-parameter, and six three-parameter equilibrium models were used for interpretation of the obtained data. Among the two and three-parameter isotherm models applied, the Jovanovic and the Khan isotherms showed the best fit, respectively. And the pseudo-second order model presented a better fit than other kinetic models. Finally, a computer-based modeling approach was developed and used for predicting the kinetics of... 

A fundamental chemical enhanced oil recovery (EOR) process is surfactant flooding in which the key mechanism is to reduce interfacial tension between oil and the displacing fluid and hence mobilizing the trapped oil. Surfactant loss by adsorption is one of the most important criteria that governs the economics of the surfactant flooding methods. In addition to this, detrimental effects and high price of currently used surfactants cause EOR process so expensive and unfeasible. This study is aimed to introduce a novel kind of plant based surfactant which is extracted from Zizyphus Spina-Christi tree. In addition, equilibrium adsorption behavior of this novel biosurfactant in aqueous solution... 

This paper presents a state of the art review of adsorption models for a new plant-based surfactant adsorption onto sandstone minerals. The adsorption data at both kinetic and equilibrium modes were obtained from batch experiments. Four adsorption kinetic models, five two-parameter, and six three-parameter equilibrium models were used for interpretation of the obtained data. Among the two and three-parameter isotherm models applied, the Jovanovic and the Khan isotherms showed the best fit, respectively. And the pseudo-second order model presented a better fit than other kinetic models. Finally, a computer-based modeling approach was developed and used for predicting the kinetics of... 

The 3A zeolites are excellent adsorbents for industrial-scale gas dehydration because of the low energy required for regeneration and ease of operation. A computational study of the dehydration of an industrial feed stream containing ethane and water was performed using an in-house code that included an appropriate equilibrium adsorption isotherm. The validated computational model was used to examine the impact of particle size on the process dynamics and the corresponding pressure drop. The water concentration along the adsorption column was also investigated. To increase the process capacity, the packed adsorption bed was divided into two distinct layers, which were operated with different... 

In the current work, the performance of untreated nanodiamonds (UNDs) and thermally oxidized nanodiamonds (ONDs), as adsorbents for selective adsorption of methylene blue (MB) and methyl orange (MO) from aqueous media, was examined. The adsorption isotherm, initial pH, ionic strength, and thermodynamic study were investigated in batch experiments. The equilibrium adsorption data were analyzed by Langmuir and Freundlich isotherm models, which indicated that the isotherms were well fitted with the Langmuir model for both dyes. Thermodynamic parameters indicated that the adsorption operation was a feasible, spontaneous, and physisorption process in experimental conditions. Meanwhile, the... 

In the current work, the performance of untreated nanodiamonds (UNDs) and thermally oxidized nanodiamonds (ONDs), as adsorbents for selective adsorption of methylene blue (MB) and methyl orange (MO) from aqueous media, was examined. The adsorption isotherm, initial pH, ionic strength, and thermodynamic study were investigated in batch experiments. The equilibrium adsorption data were analyzed by Langmuir and Freundlich isotherm models, which indicated that the isotherms were well fitted with the Langmuir model for both dyes. Thermodynamic parameters indicated that the adsorption operation was a feasible, spontaneous, and physisorption process in experimental conditions. Meanwhile, the... 

In the current work, the performance of untreated nanodiamonds (UNDs) and thermally oxidized nanodiamonds (ONDs), as adsorbents for selective adsorption of methylene blue (MB) and methyl orange (MO) from aqueous media, was examined. The adsorption isotherm, initial pH, ionic strength, and thermodynamic study were investigated in batch experiments. The equilibrium adsorption data were analyzed by Langmuir and Freundlich isotherm models, which indicated that the isotherms were well fitted with the Langmuir model for both dyes. Thermodynamic parameters indicated that the adsorption operation was a feasible, spontaneous, and physisorption process in experimental conditions. Meanwhile, the... 

This paper concerns with the interfacial tension (IFT), wettability modification and adsorption behavior of a new plant-based surface active agent, Zizyphus Spina Christi, onto sandstone minerals which has been rarely attended in the available literature. Both kinetics and equilibrium adsorption data were obtained from batch mode tests. It was revealed that Freundlich isotherms matched better fit to the equilibrium data which implied that multilayer coverage of Zizyphus Spina Christi onto the sandstone particle surfaces was more likely to occur. Analysis of experimental kinetic data based on intraparticle diffusion model disclosed that the intraparticle diffusion mechanism is not the only... 

Condensate and water banking around gas condensate wells result in vital well deliverability issues. Wettability alteration of near wellbore region to gas wetting condition is known to be the most novel and the only permanent method, to improve condensate well productivity. In this work, a water based nanofluid is used to change the wettability of sandstone reservoir rocks from strongly liquid wetting to intermediate gas wetting condition. Static contact angle measurements demonstrated significant increase of liquid phase contact angle as a result of chemical treatment with SurfaPore M nanofluid. The characteristics of SurfaPore M adsorption on sandstone rock are quantified through kinetic... 

The chitosan/poly vinyl alcohol membrane was modified by addition of some amine group to the membrane structure utilizing polyethyleneimine (PEI) in order to increase ionic metals adsorbent properties of the membrane. The removal percentage of the modified membranes was compared with the pristine membrane and activated carbon as common adsorbents. The membranes were characterized by FTIR, SEM, swelling degree and porosity measurement. The removal percentage of the membrane containing 0.5 wt.% PEI was more than 60% higher than the activated carbon and more than 40% higher than the pristine membrane. The modified membrane showed excellent adsorption capacity of 112.13, 86.08, and 75.5 mg/g for...