scholarly journals Branched-Pore Kinetic Model for Basic Dyestuff Adsorption onto Natural Clay

1992 ◽  
Vol 9 (3) ◽  
pp. 199-211 ◽  
Author(s):  
Mohammad S. El-Geundi
Keyword(s):  
Aqueous Solution ◽  
Mass Transfer ◽  
Kinetic Model ◽  
External Mass Transfer ◽  
Natural Clay ◽  
Main Mass ◽  
Micropore Diffusion ◽  
Concentration Time ◽  
Transfer Parameters ◽  
Best Fit

The adsorption of Basic Blue 69 from aqueous solution onto natural clay has been studied using an agitated batch adsorber. The branched-pore kinetic model (BPKM). based on external mass transfer, macropore diffusion and micropore diffusion, has been used to predict the performance of a batch adsorber. A computer program has been developed to generate theoretical concentration-time curves and these results adjusted to experimental concentration-time curves by a ‘best fit’ approach. A sensitivity analysis has been performed to study the effect of the main mass-transfer parameters, Ks, Ds, Kb and f, on the shape of the concentration decay curves. The variables of initial dye concentration and natural clay mass have been successfully correlated using constant values of the mass-transfer parameters Ks, Ds, Kb and f. The Ks value is (3.7 ± 0.1) × 10−3 cm/s, the Ds value is (2.6 ± 0.1) × 10−8 cm2/s. the Kb value is (1.7 ± 0.1) × 10−7 cm/s and finally the f value is 0.56 ± 0.01. The micropore diffusion terms enable the concentration decay curves to be predicted accurately for a longer period of time than in previous models.

scholarly journals Homogeneous Surface Diffusion Model for the Adsorption of Basic Dyestuffs onto Natural Clay in Batch Adsorbers

1991 ◽  
Vol 8 (4) ◽  
pp. 217-225 ◽  
Author(s):  
Mohammad S. El-Geundi
Keyword(s):  
Mass Transfer ◽  
Surface Diffusion ◽  
Diffusion Model ◽  
Batch Adsorption ◽  
External Mass Transfer ◽  
Natural Clay ◽  
Homogeneous Surface ◽  
Concentration Time ◽  
Ks Values ◽  
Best Fit

The adsorption of basic dyestuffs (Basic Blue 69 and Basic Red 22) onto natural clay has been studied using a series of batch adsorption runs. The homogeneous surface diffusion model (HSDM) has been developed based on external mass transfer and surface diffusion to explain the concentration–time curves. A computer program has been used to generate theoretical concentration–time curves and these results have been adjusted to the experimental data by means of a ‘best fit’ approach. The HSDM has been successfully used to model the dynamics of the adsorption process for basic dyestuffs onto natural clay. The model predicts a single external mass-transfer coefficient, Ks, and a single surface diffusion coefficient, Ds, with initial dye concentration or natural clay mass. The Ks values are 3.4×10–3 and 2.6×10–3 cm/s for Basic Blue 69 and Basic Red 22, respectively. The Ds values are 2.3×10–8 and 1.9×10–8 cm2/s for Basic Blue 69 and Basic Red 22, respectively.

scholarly journals Pore Diffusion Model for the Adsorption of Basic Dyestuffs onto Natural Clay in Batch Adsorbers

1992 ◽  
Vol 9 (2) ◽  
pp. 109-120 ◽  
Author(s):  
Mohammad S. El-Geundi
Keyword(s):  
Mass Transfer ◽  
Diffusion Coefficient ◽  
Diffusion Model ◽  
Sherwood Number ◽  
Pore Diffusion ◽  
Batch Adsorption ◽  
External Mass Transfer ◽  
Natural Clay ◽  
Pore Diffusion Model ◽  
Best Fit

The adsorption of basic dyestuffs (Basic Blue 69 and Basic Red 22) onto natural clay has been studied using a series of batch adsorption runs. The pore diffusion model (PDM) has been developed based on external mass transfer and pore diffusion to predict the performance of a batch adsorber. A computer program has been developed to generate theoretical Sherwood number-time curves and these results were adjusted to experimental Sherwood number-time curves by means of a ‘best fit’ approach. The variables of initial dye concentration and natural clay mass have been successfully correlated using a single external mass-transfer coefficient, Ks, and a single effective pore diffusion coefficient, Deff. The Ks values are 3.3 × 10−5 and 2.6 × 10−5 m/s for Basic Blue 69 and Basic Red 22, respectively. The Deff values are 7.3 × 10−10 and 9.6 × 10−10 m2/s for Basic Blue 69 and Basic Red 22, respectively.

scholarly journals Comparative Mass Transfer Study of Basic and Acid Magenta Adsorption onto Natural Clay

2019 ◽  
Vol 19 (4) ◽  
pp. 1031
Author(s):  
Radia Yous ◽  
Hakima Cherifi ◽  
Razika Khalladi
Keyword(s):  
Mass Transfer ◽  
Adsorption Mechanism ◽  
Regression Coefficient ◽  
Statistical Error ◽  
Theoretical Models ◽  
External Mass Transfer ◽  
Natural Clay ◽  
Natural Adsorbents ◽  
External Model ◽  
Transfer Study

In this work a comparative study of basic and acid magenta sorption on Algerian natural untreated clay was investigated using theoretical models for the following conditions C0(BM) = 200 mg/L, C0(AM) = 150 mg/L, V = 500 mL, CB(BM) = 1g/L, T = 22 °C. Adsorption mechanism of both dyes based on an intraparticle diffusion, external mass transfer, and kinetic models was examined. Statistical error functions regression coefficient (R2), the root mean square error (RMSE) and the average relative error deviation ARED were used to estimate the deviation between experimental and theoretical values. This work indicated that the experimental results obtained for both dyes fitted well the chosen models in the following order: External model of Boyd < Kinetic model < Urano and Tachikawa model < External model of Weber and Morris ≤ Weber and Morris internal diffusion model. However, the calculated values of Biot number are 32.31 and 69.33 for acid magenta and basic magenta respectively, indicating that the adsorption of both dyes onto the same clay is initially controlled by external film diffusion at the first ten minutes. The adsorption capacity of the tested clay for both dyes is remarkable compared to other natural adsorbents. Where the best results were obtained for basic magenta (qexp = 198.028 mg g–1, R2 = 0.992, ARED = 0.128 and RMSE = 0.461).

scholarly journals Adsorption Kinetics of Cationic Dyestuffs on to Natural Clay

1996 ◽  
Vol 13 (4) ◽  
pp. 295-303 ◽  
Author(s):  
Mohammad S. El-Geundi
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Size Range ◽  
External Mass Transfer ◽  
Natural Clay ◽  
Particle Size Range ◽  
Design Variables ◽  
Step Model ◽  
Kinetics Of

A three-step model has been proposed for the adsorption of cationic dyestuffs (Basic Blue 69 and Basic Red 22) from aqueous solutions on to natural clay. The rate of adsorption is controlled initially by the boundary layer film and an external mass-transfer coefficient Ks has been determined for this process under the influence of a number of design variables. Two approaches, designated methods 1 and 2, are available for determining the external mass-transfer coefficient. Using log-log correlations, the external mass-transfer coefficient was found to vary linearly with the agitation speed, the clay particle size range and the mass of clay employed.

scholarly journals Sorption behavior and mechanism of oxytetracycline from simulated wastewater by Amberlite IR-120 resin

2020 ◽  
Vol 82 (11) ◽  
pp. 2366-2380
Author(s):  
Rechidi Yousef ◽  
Chabani Malika
Keyword(s):  
Aqueous Solution ◽  
Mass Transfer ◽  
Diffusion Coefficient ◽  
Transfer Coefficient ◽  
Effective Diffusion Coefficient ◽  
Effective Diffusion ◽  
Transfer Model ◽  
Mass Transfer Model ◽  
External Mass Transfer ◽  
Pseudo Second Order

Abstract The adsorption of oxytetracycline from aqueous solution by the resin Amberlite IR 120 was studied. The effect of different experimental parameters such as contact time, initial concentration of OTC 40–200 mg/l, initial pH 2–12 of aqueous solution, adsorbent dose 0.5–3 g/l, and stirring speed 100–700 rpm on the adsorption of OTC were investigated. The kinetic adsorption experimental results were analyzed using pseudo-first order, pseudo-second order and Elovich kinetic models. The adsorption process was found to follow a pseudo-second order kinetic model and the corresponding rate constants were obtained. A film-pore diffusion (FPD) mass transfer model has been developed to predict the concentration distribution in the fluid phase, based on the external mass transfer coefficient and the effective diffusion coefficient. The values of the external mass transfer coefficient (βL) and effective diffusion coefficient (Deff) were found to decrease with increasing OTC concentration. The comparison between the experimental and the theoretical curves allowed us to note that the film-pore diffusion mass transfer model gave a good agreement with the experimental data for all the values of initial OTC concentration.

Nitrate and chloride formation in chloramination

1994 ◽  
Vol 30 (9) ◽  
pp. 101-110
Author(s):  
V. Diyamandoglu
Keyword(s):  
Kinetic Model ◽  
Analytical Method ◽  
Kinetic Data ◽  
Experimental Results ◽  
Mass Balances ◽  
Time Profiles ◽  
Slow Decay ◽  
Concentration Time ◽  
End Products ◽  
Chlorine Residuals

The formation of nitrate and chloride as end-products of chloramination (combined chlorination) was investigated at pH ranging between 6.9 and 9.6 at 25°C. The experimental results comprised concentration-time profiles of combined chlorine residuals along with nitrate and chloride. Nitrite, if present, was always below the detectibility limit of the analytical method used (25 ppb). Mass balances on chlorine species depicted that chloride formed during the slow decay of combined chlorine residuals does not account for all the chlorine lost. This substantiates the formation of other reaction end-products which are yet to be identified. A kinetic model for chloramination is proposed based on the kinetic data obtained in this study.

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