scholarly journals Study of Mass Transfer Coefficient of Cephalexin Adsorption onto Walnut Shell-Based Activated Carbon in a Fixed-Bed Column

2016 ◽  
Vol 10 (1) ◽  
pp. 81-86 ◽  
Author(s):  
Ghadir Nazari ◽  
◽  
Hossein Abolghasemi ◽  
Mohamad Esmaieli ◽  
◽  
...  
Keyword(s):  
Mass Transfer ◽  
Activated Carbon ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Fixed Bed ◽  
Walnut Shell ◽  
Fixed Bed Column

scholarly journals Dynamic studies of nitrophenols sorption on perfil in a fixed-bed column

2008 ◽  
Vol 27 (2) ◽  
pp. 123 ◽  
Author(s):  
Zvezdelina Yaneva ◽  
Mirko Marinkovski ◽  
Liljana Markovska ◽  
Vera Meshko ◽  
Bogdana Koumanova
Keyword(s):  
Mass Transfer ◽  
Diffusion Coefficient ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Dispersion Coefficient ◽  
Fixed Bed ◽  
External Mass Transfer ◽  
Fixed Bed Column ◽  
Axial Dispersion Coefficient ◽  
Solid Diffusion

The adsorption of two substituted nitrophenols, namely 4-nitrophenol (4-NP) and 2,4-dinitrophenol (2,4-DNP), from aqueous solutions onto perfil was studied using a fixed bed column. The theoretical solid diffusion control (SDC) model describing single solute adsorption in a fixed bed based on the Linear Driving Force (LDF) kinetic model was successfully applied to the investigated systems. The model parameters of solid diffusion coefficient, DS, axial dispersion coefficient, DL, and external mass transfer coefficient, kf, for the investigated systems were estimated by the means of a best fit approach. Some deviations were found between the predicted and the experimental data which reflect the fact that the assumptions of the model were not quite fulfilled for these experiments. It is necessary to adjust the values of the solid diffusion coefficient, the axial dispersion coefficient and the external mass transfer coefficient in order to obtain a satisfactory agreement between the simulated and the experimental breakthrough curves. A Biot number was used as an indicator for the intarparticle diffusion. The Biot number was found to decrease with the increase of bed depth, indicating that the film resistance increased or the intraparticle diffusion resistance decreased.

scholarly journals Investigating the performance of agricultural wastes and their ashes in removing phenol from leachate in a fixed-bed column

2020 ◽  
Vol 81 (10) ◽  
pp. 2109-2126 ◽  
Author(s):  
Seyed Omid Ahmadinejad ◽  
Seyed Taghi Omid Naeeni ◽  
Zahra Akbari ◽  
Sara Nazif
Keyword(s):  
Activated Carbon ◽  
Large Scale ◽  
Fixed Bed ◽  
Walnut Shell ◽  
Continuous Systems ◽  
Phenol Removal ◽  
Adsorption Method ◽  
Fixed Bed Column ◽  
Saturation Time ◽  
Coconut Shell Activated Carbon

Abstract One of the major pollutants in leachate is phenol. Due to safety and environmental problems, removal of phenol from leachate is essential. Most of the adsorption studies have been conducted in batch systems. Practically, large-scale adsorption is carried out in continuous systems. In this research, the adsorption method has been used for phenol removal from leachate by using walnut shell activated carbon (WSA) and coconut shell activated carbon (CSA) as adsorbents in a fixed-bed column. The effect of adsorbent bed depth, influent phenol concentration and type of adsorbent on adsorption was explored. By increasing the depth of the adsorbent bed in the column, phenol removal efficiency and saturation time increase significantly. Also, by increasing the influent concentration, saturation time of the column decreases. To predict the column performance and describe the breakthrough curve, three kinetic models of Yon-Nelson, Adams-Bohart and Thomas were applied. The results of the experiments indicate that there is a good match between the results of the experiment and the predicted results of the models.

Study of the Process of Wastewater Treatment with Activated Caron from Dimethylamine and Dimethylformamide in their Joint Presence

2021 ◽  
Vol 25 (2) ◽  
pp. 18-22
Author(s):  
Yu.V. Solovyova ◽  
V.P. Yustratov ◽  
N.S. Golubeva ◽  
I.V. Vasiljeva ◽  
E.V. Nazimova
Keyword(s):  
Mathematical Modeling ◽  
Mass Transfer ◽  
Wastewater Treatment ◽  
Activated Carbon ◽  
Aqueous Solutions ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Adsorption Column ◽  
Limiting Stage ◽  
Column Process

The regularities and mechanism of adsorption of dimethylformamide and dimethylamine by industrial activated carbon in their joint presence from aqueous solutions are considered. The characteristics of equilibrium adsorption, the limiting stage, and the mass transfer coefficient have been determined. The main parameters of the adsorption column process and the mode of continuous cleaning are calculated by the method of mathematical modeling.

Linear Driving Force Model in Carbon Dioxide Capture by Adsorption

2016 ◽  
Vol 830 ◽  
pp. 38-45 ◽  
Author(s):  
Leonardo Hadlich de Oliveira ◽  
Joziane Gimenes Meneguin ◽  
Edson Antonio da Silva ◽  
Maria Angélica Simões Dornellas de Barros ◽  
Pedro Augusto Arroyo ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Breakthrough Curve ◽  
Driving Force ◽  
Fixed Bed ◽  
Isotherm Models ◽  
Force Model ◽  
Transfer Resistance ◽  
Linear Driving Force

In this work, experimental data of CO2 capture by adsorption was determined gravimetrically, at 30 °C and pressures up to 40 bar, and in a fixed bed unit at 20 bar, using NaY as adsorbent. Langmuir, Sips and Tóth isotherm models were used to correlate the equilibrium data. Sips and Tóth models were best fitted allowing estimate the maximum CO2 adsorbed amount. The breakthrough curve was modeled using Linear Driving Force (LDF) and Thomas models. The LDF model represented better the CO2 breakthrough curve than Thomas model. The mass transfer resistance in NaY micropores can be assumed as the limiting step for CO2 adsorption in fixed bed, since the intraparticle mass transfer coefficient of LDF model was smaller than the experimental overall volumetric mass transfer coefficient, although external film resistance is not negligible.

scholarly journals Kinetic and equilibrium study of the removal of reactive dye using modified walnut shell

2019 ◽  
Vol 80 (5) ◽  
pp. 874-883 ◽  
Author(s):  
Shenmaishang Li ◽  
Zuoxiang Zeng ◽  
Weilan Xue
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Adsorption Capacity ◽  
Diffusion Mechanism ◽  
Aqueous Media ◽  
Reactive Dye ◽  
Walnut Shell ◽  
Batch Adsorption ◽  
Surface Mass

Abstract Modified walnut shell (EAWNS) was prepared by reaction with epichlorohydrin and alkaline solution of aspartic acid and used to remove reactive dye (Reactive Brilliant Blue (KN-R)) from aqueous media. The isotherms, kinetics and thermodynamics of KN–R adsorption onto EAWNS were studied at 298–318 K. The isotherm data of KN–R adsorption onto EAWNS agreed closely with the Langmuir model. The theoretical monolayer adsorption capacity for KN–R was 224.42 mg/g at 318 K. The result from the Dubinin–Radushkevich model showed that the KN–R adsorption onto EAWNS is chemisorption. The adsorption rate of KN–R onto EAWNS conformed to the pseudo-second-order model. The diffusion mechanism was investigated by the intraparticle diffusion model. The mass-transfer coefficient calculated by the surface mass-transfer coefficient model was in range of 2.95 × 10−5 to 2.93 × 10−4cm/s. The thermodynamic results suggested that the adsorption of KN–R onto EAWNS is spontaneous and endothermic in nature. The design of a single-stage batch adsorption process based on EAWNS adsorbent was carried out. Furthermore, the recycled EAWNS maintains high adsorption capacity despite four cycles.

Oxygen Mass Transfer Coefficients in a Three-Phase Pulsed Plate Bioreactor

2010 ◽  
Vol 8 (1) ◽  
Author(s):  
K.V. Shetty ◽  
G. Srinikethan
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Immobilized Cells ◽  
Fixed Bed ◽  
Oxygen Mass Transfer ◽  
Transfer Coefficients ◽  
Mass Transfer Coefficients ◽  
Three Phase ◽  
Plate Column

Volumetric oxygen mass transfer coefficient is a decisive parameter for the selection of any contactor as an aerobic bioreactor. A pulsed plate column with fixed bed of solids in interplate spaces is a recent innovation in the field of immobilized cell bioreactors. Volumetric oxygen mass transfer coefficients are determined in a three-phase pulsed plate column involving air and water phases and with a fixed bed of glass particles, which can serve as a surface for cell immobilization packed in the interplate spaces. The volumetric mass transfer coefficients obtained in this column range from 0.067 to 0.1495 s-1 in the range of air superficial velocities from 0.011 to 0.047m/s and vibrational velocities from 0.825 to 6cm/s. Volumetric oxygen mass transfer coefficient has increased with the increase in superficial air velocity and vibrational velocity. Empirical correlation relating kLa with these variables was developed. The volumetric oxygen mass transfer coefficient values in the three-phase pulsed plate column are found to be similar or higher than the literature reported values for conventional two-phase pulsed plate columns. The values of volumetric oxygen mass transfer coefficients in the three-phase pulsed plate column are of higher order of magnitude than the literature reported values of volumetric oxygen mass transfer coefficient for many other three-phase gas-liquid-solid reactors. The pulsed plate column with fixed bed of solids is proven to have all the potential to be used as an aerobic bioreactor with immobilized cells due to its better gas-liquid mass transfer characteristics.

Evaluation of mass transfer mechanisms involved during the adsorption of metronidazole on granular activated carbon in fixed bed column

2020 ◽  
Vol 36 ◽  
pp. 101303 ◽  
Author(s):  
V. Díaz-Blancas ◽  
C.G. Aguilar-Madera ◽  
J.V. Flores-Cano ◽  
R. Leyva-Ramos ◽  
E. Padilla-Ortega ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Activated Carbon ◽  
Fixed Bed ◽  
Granular Activated Carbon ◽  
Fixed Bed Column ◽  
Transfer Mechanisms

Correlation of mass transfer coefficient in the extraction of plant oil in a fixed bed for supercritical CO2

2007 ◽  
Vol 78 (1) ◽  
pp. 33-40 ◽  
Author(s):  
John Shi ◽  
Yukio Kakuda ◽  
Xiaoqin Zhou ◽  
Gauri Mittal ◽  
Qinmin Pan
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Supercritical Co2 ◽  
Fixed Bed ◽  
Plant Oil

scholarly journals A Taguchi approach for optimization of mass transfer coefficient in metronidazole drug delivery process and activated carbon as a carrier

2021 ◽  
Vol 9 (4A) ◽  
Author(s):  
Shahad F. Hameed ◽  
◽  
Salih Rushdi ◽  
Zainab T. Al-Sharify ◽  
◽  
...  
Keyword(s):  
Drug Delivery ◽  
Mass Transfer ◽  
Activated Carbon ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Drug Loading ◽  
Weight Ratio ◽  
Drug Efficacy ◽  
Optimum Point ◽  
Carbon Molecules

New strategies have been developed in the drug delivery system in recent years for applications like pharmacokinetics control, pharmacodynamics, undetermined toxicity, immunity, biophysics, and drug efficacy. The loading process was based on adsorption between activated carbon molecules' surfaces and drug molecules dissolved in ethanol at room temperature, where porous activated carbon has great drug delivery characteristics. The current research is studying the effect of the number of parameters including particle size, the weight of drug to the carrier, weight ratio, drug loading and temperature, time, and pH solution on mass transfer coefficient. The Taguchi program's result shows that the optimum point of maximum loading efficiency is 74% when the activated carbon in nanoparticle was in 11.042 nm size, and 985.6013 m2/g surface area weight drug to AC weight ratio is 1.5. The drug process release obtained an optimum point that gives a better value of mass transfer coefficient of 0.0007777 and 0.0003372 cm/hr in the first hour, 37°C, and pH of 1.5 solutions for both metronidazole/macro AC and metronidazole/Nano AC complexes.

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