A comparative study of lead adsorption by activated Khaya Ivoresnsis and Pycanthus Angolensis sawdust

2016 ◽  
Vol 6 (4) ◽  
pp. 593-601
Author(s):  
Chidozie Charles Nnaji ◽  
Stephen Chinwike Emefu
Keyword(s):  
Experimental Data ◽  
Freundlich Isotherm ◽  
Intraparticle Diffusion ◽  
Bulk Liquid ◽  
Timber Species ◽  
Particle Sizes ◽  
Lead Adsorption ◽  
Intraparticle Diffusion Model ◽  
First Order Kinetics ◽  
Good Agreement

Experiments investigating lead adsorption by activated sawdust of different particle sizes of two timber species were conducted. The experimental data were fitted to isothermal and kinetic models. The optimum particle size was 0.85 mm for Khaya ivorensis and 1.18 mm for Pycanthus angolensis. The adsorption of lead by Khaya ivorensis and Pycanthus angolensis conformed to the Langmuir isotherm (0.83 ≤ R2 ≤ 0.96 and 0.86 ≤ R2 ≤ 0.98, respectively) and Freundlich isotherm (0.69 ≤ R2 ≤ 0.97 and 0.94 ≤ R2 ≤ 1.0, respectively). The adsorption process for the two species of timber was controlled by solute transport in the bulk liquid and intraparticle diffusion which was confirmed by good agreement of experimental data with pseudo-first-order kinetics (0.96 ≤ R2 ≤ 1.0 for Khaya ivorensis and 0.9 ≤ R2 ≤ 1.0 for Pycanthus angolensis) and the intraparticle diffusion model (0.9 ≤ R2 ≤ 0.99 for Khaya ivorensis and 0.84 ≤ R2 ≤ 0.97 for Pycanthus angolensis). A new kinetic model was developed with R2 of 0.93 ≤ R2 ≤ 0.99 for Khaya ivorensis and 0.88 ≤ R2 ≤ 1.0 for Pycanthus angolensis.

scholarly journals Dye removal abilities of the mesophilic and thermophilic biomass: a kinetics study

2018 ◽  
Vol 20 (2) ◽  
pp. 408-416
Keyword(s):  
Intraparticle Diffusion ◽  
Second Order ◽  
Intraparticle Diffusion Model ◽  
First Order Kinetics ◽  
Different Types ◽  
Pseudo Second Order ◽  
Acidic Conditions ◽  
Red Dye ◽  
Experimental Kinetics ◽  
Kinetics Of

Mesophilic biomass and thermophilic biomass samples were isolated and used to remove Dorasyn Red dye from aqueous solutions. The biosorption kinetics of dye uptake by four different types of biomass at three temperatures (20, 30, and 40 °C) were investigated using pseudo-first order kinetics, pseudo-second order kinetics, intraparticle diffusion, Elovich, and Bangham models. The pseudo-second-order kinetics model and the first stage of the intraparticle diffusion model were effective in describing the experimental kinetics data. The biosorption results showed that the mesophilic biomass samples could be useful for removing dye under acidic conditions.

scholarly journals Removal of Fluoride from Drinking Water by Sorption Using Diatomite Modified with Aluminum Hydroxide

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Tesfaye Akafu ◽  
Achalu Chimdi ◽  
Kefyalew Gomoro
Keyword(s):  
Aluminum Hydroxide ◽  
Contact Time ◽  
Fluoride Concentration ◽  
Freundlich Isotherm ◽  
Intraparticle Diffusion ◽  
Fluoride Removal ◽  
Contaminated Water ◽  
Optimum Conditions ◽  
Intraparticle Diffusion Model ◽  
Adsorbent Dose

Exposure to fluoride beyond the recommended level for longer duration causes both dental and skeletal fluorosis. Thus, the development of cost-effective, locally available, and environmentally benign adsorbents for fluoride removal from contaminated water sources is absolutely required. In the present study, diatomaceous earth (diatomite) locally available in Ethiopia, modified by treating it with an aluminum hydroxide solution, was used as an adsorbent for fluoride removal from aqueous solutions. Adsorption experiments were carried out by using batch contact method. The adsorbent was characterized using FT-IR spectroscopy. Effects of different parameters affecting efficiency of fluoride removal such as adsorbent dose, contact time, initial fluoride concentration, and pH were investigated and optimized. The optimum adsorbent dose, contact time, initial fluoride concentration, and pH values were 25 g/L, 180 min, 10 mg/L, and 6.7, respectively. The performance of the adsorbent was also tested under optimum conditions using groundwater samples taken from Hawassa and Ziway. Langmuir and Freundlich isotherm models were applied to describe the equilibrium data. Compared to Langmuir isotherm (R2 = 0.888), the Freundlich isotherm (R2 = 0.985) model was better fitted to describe the adsorption characteristics of fluoride on Al-diatomite. The Langmuir maximum adsorption capacity was 1.67 mg/g. The pseudosecond-order model was found to be more suitable than the pseudofirst-order to describe the adsorption kinetics. The low correlation coefficient value of R2 = 0.596 for the intraparticle diffusion model indicates that the intraparticle diffusion model does not apply to the present studied adsorption system. The maximum fluoride removal was observed to be 89.4% under the optimum conditions which indicated that aluminum hydroxide-modified diatomite can be used as efficient, cheap, and ecofriendly adsorbents for the removal of fluoride from contaminated water.

scholarly journals Synthesis of New Cyclodextrin-Based Adsorbents to Remove Direct Red 83:1

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1880
Author(s):  
José A. Pellicer ◽  
María Isabel Rodríguez-López ◽  
María Isabel Fortea ◽  
Vicente M. Gómez-López ◽  
David Auñón ◽  
...  
Keyword(s):  
Room Temperature ◽  
Advanced Oxidation Process ◽  
Oxidation Process ◽  
Freundlich Isotherm ◽  
Intraparticle Diffusion ◽  
Isotherm Models ◽  
Intraparticle Diffusion Model ◽  
Pseudo Second Order ◽  
Physical Interactions ◽  
Resonance Particle

Two cyclodextrins (CDs), γ– and hydroxypropyl (HP)–γ–CDs were used to synthesize new adsorbents by using epichlorohydrin (EPI) as cross-linking agent in order to remove Direct Red 83:1 (DR) from water. Both polymers were characterized in terms of Fourier spectroscopy, nuclear magnetic resonance, particle size distribution and thermogravimetric analysis. Experimental data for both polymers were well fitted to the pseudo-second order and intraparticle diffusion model, indicating that in the adsorption both chemical and physical interactions are essential in the removal of DR. Three different isotherm models were analyzed, concluding that γ–CDs–EPI followed the Temkin isotherm and HP–γ–CDs-EPI the Freundlich isotherm, these results suggested that the adsorption was happening onto heterogeneous surfaces. The results of the Gibbs free energy showed that the adsorption was spontaneous at room temperature. In order to eliminate the remaining dye after the polymer treatment, and advanced oxidation process (AOP) was considered, achieving more than 90% of removal combining both mechanisms.

scholarly journals Numerical study of mixing and heat transfer of SRF particles in a bubbling fluidized bed

2019 ◽  
Vol 142 (2) ◽  
pp. 1087-1096
Author(s):  
Mohamed Sobhi Alagha ◽  
Botond Szucs ◽  
Pal Szentannai
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Fluidized Bed ◽  
Present Model ◽  
Numerical Study ◽  
Sand Particle ◽  
Particle Sizes ◽  
Proposed Model ◽  
Bubbling Fluidized Bed ◽  
Good Agreement

AbstractIn this article, numerical investigations on mixing and heat transfer of solid refused fuel (SRF) particles in a bubbling fluidized bed are carried out. The numerical model is based on the Eulerian–Eulerian approach with empirical submodels representing gas–solid and solid–solid interactions. The model is verified by experimental data from the literature. The experimental data include SRF vertical distribution in SRF–sand mixtures of different sand particle sizes ($$d_{\mathrm{pm}} = 654,810$$ d pm = 654 , 810 and 1110 $$\upmu$$ μ m) at different fluidization velocities ($$u/u_{\mathrm{mf}} = 1.2$$ u / u mf = 1.2 –2.0). We proposed magnification of drag force exerted by the gas on SRF particles based on Haider and Levenspiel (Powder Technol 58(1):63–70, 1989) drag coefficient. The proposed model shows good agreement with the experimental data at high fluidization velocities ( $$u/u_{\mathrm{mf}} = 1.5$$ u / u mf = 1.5 –2.0) and poor predictions at low fluidization velocities ($$u/u_{\mathrm{mf}} = 1.2$$ u / u mf = 1.2 –1.5). Heat transfer results showed that the present model is valid and gives good agreement with the experimental data of wall–bed heat transfer coefficient.

scholarly journals Metal-Organic Framework-101 (MIL-101): Synthesis, Kinetics, Thermodynamics, and Equilibrium Isotherms of Remazol Deep Black RGB Adsorption

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Vo Thi Thanh Chau ◽  
Huynh Thi MinhThanh ◽  
Pham Dinh Du ◽  
Tran Thanh Tam Toan ◽  
Tran Ngoc Tuyen ◽  
...  
Keyword(s):  
Experimental Data ◽  
Diffusion Model ◽  
Kinetic Models ◽  
Adsorption Process ◽  
Metal Organic Framework ◽  
Intraparticle Diffusion ◽  
Order Kinetic ◽  
Intraparticle Diffusion Model ◽  
Metal Organic ◽  
Organic Framework

In the present paper, the synthesis of metal-organic framework-101 (MIL-101) and Remazol Deep Black RGB (RDB) adsorption on MIL-101 were demonstrated. The kinetics of RDB adsorption on MIL-101 was studied using Weber’s intraparticle diffusion model and the pseudo-first- and pseudo-second-order kinetic models. Particularly, the statistical method of piecewise linear regression and multi-nonlinear regression was employed to analyse the adsorption data according to the previously mentioned kinetic models. The results indicated that the adsorption process followed the three-step pseudo-first-order kinetic equation, which was consistent with the results of the intraparticle diffusion model with three linear segments. This model best described the experimental data. In addition, the adsorption isotherm data were studied using five adsorption models, namely, Langmuir, Freundlich, Redlich–Peterson, Toth, and Sips in nonlinear forms, and the Langmuir model is the most appropriate for the experimental data. The values of energies of activation of adsorption were calculated, and they revealed that the adsorption process was of endothermic chemical nature. A statistical comparison using Akaike information criterion to estimate the goodness of fit of the kinetic and isotherm models was presented.

Micro-thermal field-flow fractionation in the characterization of macromolecules and particles: Effect of the steric exclusion mechanism

e-Polymers ◽  
2003 ◽  
Vol 3 (1) ◽  
Author(s):  
Josef Janča ◽  
Irina A. Ananieva
Keyword(s):  
Experimental Data ◽  
Thermal Field ◽  
Separation Mechanism ◽  
Particle Sizes ◽  
Field Flow Fractionation ◽  
Steric Exclusion ◽  
Extended Range ◽  
Exclusion Mechanism ◽  
Good Agreement

Abstract The influence of the steric exclusion mechanism on the dependence of the retention on the thickness of the micro-TFFF channel was studied theoretically. A good agreement of theory with experimental data was found. In order to preserve the use of micro-TFFF within an extended range of molar masses and particle sizes, the thickness of the channel cannot be reduced without taking into account a possible deterioration of the separation due to the contribution of steric exclusion to the separation mechanism.

scholarly journals Removal of Disperse Blue 56 and Disperse Red 135 dyes from aqueous dispersions by modified montmorillonite nanoclay

2017 ◽  
Vol 23 (1) ◽  
pp. 21-29 ◽  
Author(s):  
Javad Ahmadishoar ◽  
Hajir Bahrami ◽  
Barahman Movassagh ◽  
Hosein Amirshahi ◽  
Mokhtar Arami
Keyword(s):  
Dye Adsorption ◽  
Freundlich Isotherm ◽  
Intraparticle Diffusion ◽  
Second Order ◽  
Isotherm Models ◽  
Disperse Dyes ◽  
Order Kinetic ◽  
Intraparticle Diffusion Model ◽  
Modified Montmorillonite ◽  
Pseudo Second Order

In this study modified montmorillonite was used as an adsorbent for the removal of two selected disperse dyes i.e., Disperse Blue 56 (DB) and Disperse Red 135 (DR) from dye dispersions. The adsorption equilibrium data of dyes adsorption were investigated by using Nernst, Freundlich and Langmuir isotherm models. The adsorption kinetics was analyzed by using different models including pseudo-first-order, pseudo-second-order, Elovich and Intraparticle diffusion model. The Freundlich isotherm was found to be the most appropriate model for describing the sorption of the dyes on modified nanoclay. The best fit to the experimental results was obtained by using the pseudo-second-order kinetic equation, which satisfactorily described the process of dye adsorption. Although different kinetic models may control the rate of the adsorption process, the results indicated that the main rate limiting step was the intraparticle diffusion. The results showed that the proposed modified montmorillonite could be used as an effective adsorbent for the removal of disperse dyes even from highly concentrated dispersions.

Energy Levels and Electromagnetic Transition of 90-94mo Nuclei Using Ibm-1

2020 ◽  
pp. 149-152
Keyword(s):  
Experimental Data ◽  
Transition Probability ◽  
Energy Levels ◽  
Dynamical Symmetry ◽  
Interacting Boson Model ◽  
Excitation Energies ◽  
Electromagnetic Transition ◽  
Boson Model ◽  
Energy States ◽  
Good Agreement

The energy states for the J , b , ɤ bands and electromagnetic transitions B (E2) values for even – even molybdenum 90 – 94 Mo nuclei are calculated in the present work of "the interacting boson model (IBM-1)" . The parameters of the equation of IBM-1 Hamiltonian are determined which yield the best excellent suit the experimental energy states . The positive parity of energy states are obtained by using IBS1. for program for even 90 – 94 Mo isotopes with bosons number 5 , 4 and 5 respectively. The" reduced transition probability B(E2)" of these neuclei are calculated and compared with the experimental data . The ratio of the excitation energies of the 41+ to 21+ states ( R4/2) are also calculated . The calculated and experimental (R4/2) values showed that the 90 – 94 Mo nuclei have the vibrational dynamical symmetry U(5). Good agreement was found from comparison between the calculated energy states and electric quadruple probabilities B(E2) transition of the 90–94Mo isotopes with the experimental data .

Predicting the Effect of Tire Tread Pattern Design on Thick Film Wet Traction

1977 ◽  
Vol 5 (1) ◽  
pp. 6-28 ◽  
Author(s):  
A. L. Browne
Keyword(s):  
Experimental Data ◽  
Network Design ◽  
Thick Film ◽  
Digital Computer ◽  
Analytical Tool ◽  
Design Practice ◽  
Pattern Design ◽  
Performance Results ◽  
Good Agreement

Abstract An analytical tool is presented for the prediction of the effects of changes in tread pattern design on thick film wet traction performance. Results are reported for studies in which the analysis, implemented on a digital computer, was used to determine the effect of different tread geometry features, among these being the number, width, and lateral spacing of longitudinal grooves and the angle of zigzags in longitudinal grooves, on thick film wet traction. These results are shown to be in good agreement with experimental data appearing in the literature and are used to formulate guidelines for tread groove network design practice.

A New Condition of Formation and Stablity of All Crystalline Systems in a Good Agreement with Experimental Data

2015 ◽  
Vol 11 (3) ◽  
pp. 3224-3228
Author(s):  
Tarek El-Ashram
Keyword(s):  
Experimental Data ◽  
Brillouin Zone ◽  
Electron Concentration ◽  
Free Electron ◽  
Lattice Point ◽  
Valence Electron ◽  
Fermi Gas ◽  
Valence Electron Concentration ◽  
Fermi Sphere ◽  
Good Agreement

In this paper we derived a new condition of formation and stability of all crystalline systems and we checked its validity andit is found to be in a good agreement with experimental data. This condition is derived directly from the quantum conditionson the free electron Fermi gas inside the crystal. The new condition relates both the volume of Fermi sphere VF andvolume of Brillouin zone VB by the valence electron concentration VEC as ;𝑽𝑭𝑽𝑩= 𝒏𝑽𝑬𝑪𝟐for all crystalline systems (wheren is the number of atoms per lattice point).

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