scholarly journals Potassium Adsorption Phenomenon in Calcareous Soils of Shahrazur Plain

2021 ◽  
pp. 95-109
Author(s):  
Kamil Sabir Saeed
Keyword(s):  
Adsorption Isotherms ◽  
Calcareous Soils ◽  
Model Fit ◽  
Coefficient Of Determination ◽  
Freundlich Model ◽  
Adsorption Phenomenon ◽  
Batch Technique ◽  
Silty Loam ◽  
Equilibrium Binding Constant ◽  
Exchangeable Form

     A laboratory study for adsorption of potassium (K) determination was conducted on six soils located in Sharazur plain from the Kurdistan Region of Iraq in 2021 using the batch technique method. Potassium (K) adsorption isotherms were achieved by equilibrating 5.0 g of soil samples with eight grades of K (0 to 300 mg L-1) as KCl in 50 ml of 0.01M CaCl2 solution. To match the data of adsorption, Freundlich, Langmuir, and Temkin adsorption isotherms were used. The results show that the amount of adsorbed K ranged between (45.78 to 52.49) % added K. The Freundlich model fit the equilibrium K adsorption data better for the Serwan location of soil (silty loam), as demonstrated by a greater coefficient of determination (R2 =0.90). The value of heterogeneity factor 1/n for the Freundlich model ranged from (0.34 to 0.47) kg mg-1, which was less than one. The sorption processes for all of the studied soils were normal adsorption. The constant of the Langmuir isotherm (KL) aligned from (0.107 to o.425) L mg-1. Smaller KL values mean that more adsorbed K would be transformed to a non-exchangeable form, either through the creation of crystalline K or through ion occultation. The RL values indicate the type of isotherm, the values of RL> 1 that means the adsorption nature to be unfavorable. The Temkin equilibrium binding constant (AT) was high for all studied soils except the soils of Bestan Sur and Grdigo locations, the high value of AT indicates high binding energy. The Temkin constant (bT) ranged from (10.46 to 13.47) J mole-1 that was related to the nature of the adsorption energy, a positive value indicates that the adsorption process is exothermic.  

scholarly journals Adsorption-Kinetic Studies of Mordant Exhaust Dyeing of Cotton and Silk Fabrics with Dye Extract of M. lucida Plant Species

2021 ◽  
Vol 75 ◽  
Author(s):  
Janani Loum ◽  
Robert Byamukama ◽  
P.A.G. Wanyama
Keyword(s):  
Adsorption Isotherms ◽  
Freundlich Isotherm ◽  
Kinetic Studies ◽  
Isotherm Models ◽  
Freundlich Model ◽  
Reaction Orders ◽  
Dyed Fabrics ◽  
Silk Fabrics ◽  
Exhaust Dyeing ◽  
Traditional Natural

ABSTRACT The kinetics and adsorption isotherms of the extremely slow traditional natural exhaust dyeing that takes many hours or days have been studied purposely to find means of improving the process. The dyeing of cotton and silk fabrics using dye extract of M. lucida at 50 °C were elucidated with graphs to predict the reaction orders and identify the appropriate adsorption isotherm model(s). Since the dye is UV active, changes in UV absorbance were used in place of changes in concentrations. The simultaneous and post mordanting methods followed pseudo-second-order reactions, hence chemisorption. However, mordant application to the dyed fabrics during post mordant followed a pseudo-first-order model, largely physisorption. Dyeing has followed Langmuir and Freundlich isotherm models with linear correlation r2 ranging between 1 and 0.998. From the Freundlich model and values of Langmuir constant RL (0.9307 to 1.0), the process is homogeneous, forming a favourable and linear monolayer. Accordingly, the dyeing speed can be improved by increasing the concentration of dye liquor. Additionally, according to the Freundlich model, higher dye intensity on fabrics is recorded in post mordanting. Keywords: adsorption isotherms, equilibrium, exhaust dyeing, mordant, rate law

scholarly journals [Copper (II)/Cellulose-Chitosan] Microspheres Complex for Dye Immobilization: Isotherm, Kinetic and Thermodynamic Analysis

2013 ◽  
Vol 8 (3) ◽  
pp. 155892501300800 ◽  
Author(s):  
Mahjoub Jabli ◽  
Faouzi Aloui ◽  
Béchir Ben Hassine
Keyword(s):  
Copper Ions ◽  
Sorption Data ◽  
Freundlich Model ◽  
Adsorption Phenomenon ◽  
Chitosan Microspheres ◽  
Chemical Structures ◽  
Adsorption Capacities ◽  
Intra Particle Diffusion ◽  
Kinetic And Thermodynamic Analysis ◽  
Acid Blue

Considered as ligands due to the presence of donor atoms in their chemical structures, and being also among the major pollutants of water, Eriochrome Black B (Erio), Calmagite (Calma) and Acid Blue 25 (AB25) were successfully immobilized on cellulose-chitosan microspheres loaded with copper ions. Prepared supports were characterized by Fourier Transform Infra-Red (FTIR) spectral study and Thermogravimetic analysis (TGA). The effect of experimental factors during dye immobilization such as pH, contact time, temperature, and initial dye concentration were studied. The experiments demonstrate that the adsorption capacities of dyes on [Cu(II)/cellulose-chitosan] are much higher than the unloaded microspheres. This indicates that these dyes can act as efficient ligands for coordinating metals already involved in [cellulose-chitosan]. At least, in the case of AB25, a 60% of difference in target removal was achieved at equilibrium. The kinetic adsorption fitted well to the intra-particle diffusion model and the corresponding rate constants were obtained. In addition, the interpretation of the equilibrium sorption data complies well with the Freundlich model. The thermodynamic parameters were also determined and the enthalpy change (ΔH&Deg;) was found to be low, between −5.93 and −20.68 Kj.mol-1, indicating that the adsorption phenomenon is exothermic and physical. A probable mechanism of the Dye/Copper(II)/cellulose-chitosan complex is also proposed.

scholarly journals How well does your model fit the data?

2001 ◽  
Vol 3 (1) ◽  
pp. 49-55 ◽  
Author(s):  
M. J. Hall
Keyword(s):  
Data Mining ◽  
Goodness Of Fit ◽  
Computer Modelling ◽  
Synthetic Data ◽  
Model Fit ◽  
Coefficient Of Determination ◽  
Input Output

Despite almost five decades of activity on the computer modelling of input–output relationships, little general agreement has emerged on appropriate indices for the goodness-of-fit of a model to a set of observations of the pertinent variables. The coefficient of efficiency, which is closely allied in form to the coefficient of determination, has been widely adopted in many data mining and modelling exercises. Values of this coefficient close to unity are taken as evidence of good matching between observed and computed flows. However, studies using synthetic data have demonstrated that negative values of the coefficient of efficiency can occur both in the presence of bias in computed outputs, and when the computed volume of flow greatly exceeds the observed volume of flow. In contrast, the coefficient of efficiency lacks discrimination for cases close to perfect reproduction. In the latter case, a coefficient based upon the first differences of the data proves to be more helpful.

scholarly journals [Copper (II)/Cellulose-Chitosan] Microspheres Complex for Dye Immobilization: Isotherm, Kinetic and Thermodynamic Analysis

2013 ◽  
Vol 8 (4) ◽  
pp. 155892501300800 ◽  
Author(s):  
Mahjoub Jabli ◽  
Faouzi Aloui ◽  
Béchir Ben Hassine
Keyword(s):  
Copper Ions ◽  
Sorption Data ◽  
Freundlich Model ◽  
Adsorption Phenomenon ◽  
Chitosan Microspheres ◽  
Chemical Structures ◽  
Adsorption Capacities ◽  
Intra Particle Diffusion ◽  
Kinetic And Thermodynamic Analysis ◽  
Acid Blue

Considered as ligands due to the presence of donor atoms in their chemical structures, and being also among the major pollutants of water, Eriochrome Black B (Erio), Calmagite (Calma) and Acid Blue 25 (AB25) were successfully immobilized on cellulose-chitosan microspheres loaded with copper ions. Prepared supports were characterized by Fourier Transform Infra-Red (FTIR) spectral study and Thermogravimetic analysis (TGA). The effect of experimental factors during dye immobilization such as pH, contact time, temperature, and initial dye concentration were studied. The experiments demonstrate that the adsorption capacities of dyes on [Cu(II)/cellulose-chitosan] are much higher than the unloaded microspheres. This indicates that these dyes can act as efficient ligands for coordinating metals already involved in [cellulose-chitosan]. At least, in the case of AB25, a 60% of difference in target removal was achieved at equilibrium. The kinetic adsorption fitted well to the intra-particle diffusion model and the corresponding rate constants were obtained. In addition, the interpretation of the equilibrium sorption data complies well with the Freundlich model. The thermodynamic parameters were also determined and the enthalpy change (ΔH°) was found to be low, between −5.93 and −20.68 Kj.mol-1, indicating that the adsorption phenomenon is exothermic and physical. A probable mechanism of the Dye/Copper(II)/cellulose-chitosan complex is also proposed.

scholarly journals Adsorption of Zn(II) ions from aqueous environment by surface modified Strychnos potatorum seeds, a low cost adsorbent

2013 ◽  
Vol 15 (3) ◽  
pp. 35-41 ◽  
Author(s):  
P. Senthil Kumar
Keyword(s):  
Experimental Data ◽  
Low Cost ◽  
Agricultural Waste ◽  
Coefficient Of Determination ◽  
Aqueous Environment ◽  
Freundlich Model ◽  
Shrinking Core ◽  
Pseudo Second Order ◽  
Strychnos Potatorum ◽  
Surface Modified

Abstract The surface modified Strychnos potatorum seeds (SMSP), an agricultural waste has been developed into an effective adsorbent for the removal of Zn(II) ions from aqueous environment. The Freundlich model provided a better fit with the experimental data than the Langmuir model as revealed by a high coefficient of determination values and low error values. The kinetics data fitted well into the pseudo-second order model with the coefficient of determination values greater than 0.99. The influence of particle diffusion and film diffusion in the adsorption process was tested by fitting the experimental data with intraparticle diffusion, Boyd kinetic and Shrinking core models. Desorption experiments were conducted to explore the feasibility of regenerating the spent adsorbent and the adsorbed Zn(II) ions from spent SMSP was desorbed using 0.3 M HCl with the efficiency of 93.58%. The results of the present study indicates that the SMSP can be successfully employed for the removal of Zn(II) ions from aqueous environment.

Activated Carbon from Corn Cob and Petai Hull as Novel Adsorbent for Lead Removal

2018 ◽  
Vol 934 ◽  
pp. 165-169 ◽  
Author(s):  
Ajeng Y.D. Lestari ◽  
Kuni Masruroh ◽  
Intan Widyastuti
Keyword(s):  
Aqueous Solution ◽  
Activated Carbon ◽  
Adsorption Capacity ◽  
Adsorption Isotherms ◽  
Adsorption Process ◽  
Carbonization Temperature ◽  
Model Fit ◽  
Lead Removal ◽  
Corn Cob ◽  
Ion Removal

Activated carbon was successfully generated from the mixture of corn cob and petai hull which served as adsorbents for Pb (II) ion removal at an aqueous solution. The activation was done using KOH at 800°C carbonization temperature. Synthetic waste used in the various concentration of 100, 200, 300, 400 and 500 ppm. The adsorption process was carried out at 30 minutes, the ratio of adsorbent mass was grouped as B (1:3 corn cobnative activated carbon/petai hullnative activated carbon), C (1:1 corn cobnative activated carbon/petai hullnative activated carbon), D (3:1, corn cobnative activated carbon/petai hullnative activated carbon), and H (1:1, corn cobmodifiedactivated carbon/petai hullmodifiedactivated carbon). The results showed that the highest adsorption capacity was found in H adsorbent that was 2,368 mg/g at concentration 300 ppm. Dubinin model fit the adsorption isotherms of B, C, D, and H.

Sorption of Phthalate Esters on Surficial Sediment of the Yangtze River, China

2014 ◽  
Vol 1073-1076 ◽  
pp. 263-267
Author(s):  
Chun Xiao Wang ◽  
Xiao Ling Shao ◽  
Xiang Yang Wu
Keyword(s):  
Adsorption Isotherms ◽  
Yangtze River ◽  
Phthalic Acid ◽  
River Sediment ◽  
Phthalate Esters ◽  
Langmuir Model ◽  
The Yangtze River ◽  
Phthalic Acid Esters ◽  
Freundlich Model ◽  
Acid Esters

The sorption of three kinds of phthalic acid esters (PAEs) in the Yangtze River sediment was investigated in this paper. Langmuir and Freundlich model were used to fit their adsorption isotherms. Results showed that Langmuir model could better fit the adsorption isotherms of PAEs in the sediment.

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