Kinetics Studies of Metallic Ions Adsorption by Immobilised Chitosan

2022 ◽  
Vol 16 (1) ◽  
pp. 137
Author(s):  
Thanabalan Pitchay ◽  
Ali H. Jawad ◽  
Ili Syazana Johari ◽  
Sumiyyah Sabar

Immobilised chitosan on glass plates was used as an adsorbent for metallic ions from aqueous solutions in a batch adsorption system. Experiments were carried out as a function of contact time and initial metallic ions concentration. The adsorption efficiency increased with increasing initial metallic ions concentration (5 – 20 mg L-1) and the observed trend was: Ag2+ > Cu2+ > Ni2+ > Fe3+ > Cd2+ > Zn2+. The experimental data were fitted to pseudo-first, pseudo-second-order, intra-particle, and liquid film diffusion kinetic models. The applicability of the pseudo-second-order kinetic model indicated that the adsorption behaviour was ascribed by chemisorption. Further data analysis by the diffusion kinetic models suggested that the metallic ions adsorption was controlled by more than one step; adsorption at the active sites, intra-particle, and liquid film diffusion.

Processes ◽  
2020 ◽  
Vol 8 (7) ◽  
pp. 852
Author(s):  
Sicong Yao ◽  
Massimiliano Fabbricino ◽  
Marco Race ◽  
Alberto Ferraro ◽  
Ludovico Pontoni ◽  
...  

Digestate, as an urban solid waste, was considered as an innovative adsorbent for colorant polluted wastewater. Batch adsorption experiments were carried out using digestate as an adsorbent material to remove various dyes belonging to different categories. The removal rate and adsorption capacity of dyes were evaluated and the dose of digestate, contact time, and initial dye concentration were studied. The maximum removal rate was approximately 96% for Methylene Blue. The equilibrium time for the Methylene Blue was 4 h, while for other dyes, a longer contact time was required to reach the equilibrium. The suspicion of colloidal matter release into the solution from solid fraction of the digestate led to the investigation of the consequence of a washing step of the digestate adsorbent upstream the adsorption experiment. Washed and not washed adsorbents were tested and the differences between them in terms of dye removal were compared. Moreover, experimental data were fitted by pseudo-first order, pseudo-second order, and intra-partial diffusion kinetic models as well as Langmuir, Freundlich, and Sips isotherm models. The results from fitted models showed that the adsorption of various dyes onto the digestate was mostly well fitted by the Langmuir isotherm and pseudo-second-order kinetic model.


Author(s):  
I. R. Ilaboya ◽  
O. C. Izinyon

Time dependent adsorption study on the sorption of Cr(III) and Mn(II) ions onto acid activated shale was conducted using batch adsorption techniques to investigate the effect of initial metal ion concentration on the process of adsorption. Experimental data obtained were fitted into different kinetic models to analyze the mechanism of adsorption in terms of reaction controlled and transport controlled mechanism. Some of the selected kinetic models include; Pseudo-first order, Pseudo-second order, Elovich, Film diffusion, Parabolic diffusion and Intra-particle diffusion model. From the result, it was observed based on the linear coefficient of determination (r2) that the experimental data fitted well into the various kinetic model tested. Application of non-linear error function such as error sum of square (SSE), root mean square error (RMSE) and residual average (RA) revealed that the rate limiting step for the adsorption of Cr3+ and Mn2+ ions on acid activated shale was chemical attachment (chemisorption) and the reaction mechanism follows the Pseudo-second order kinetic model.


2011 ◽  
Vol 8 (s1) ◽  
pp. S363-S371 ◽  
Author(s):  
C. Theivarasu ◽  
S. Mylsamy

The removal of malachite green (MG) by cocoa (Theobroma cacao) shell activated carbon (CSAC) was investigated in present study. Adsorption studies were performed by batch experiments as a function of process parameters such as initial pH, contact time, initial concentration and adsorbent dose. A comparison of kinetic models applied to the adsorption of MG on CSAC was evaluated for the pseudo-first order and pseudo-second order kinetic models. Results showed that the pseudo-second order kinetic model was found to correlate the experimental data well. The experimental equilibrium adsorption data was represented with Langmuir, Freundlich, Tempkin, Dubinin-Radushkevich and Flory-Huggins isotherms. The experimental data obtained in the present study indicated that activated carbon developed from cocoa shell can be attractive options for dye removal from waste water.


Author(s):  
P. H. Kumaraiah

Recently, low-cost adsorbents from sustainable sources are required for the remediation of textile wastewater. Carbonized Orange Peels (COPs) was utilized in remediating colour, Zinc and Copper from textile wastewater. The initial and final pH, colour and trace metals’ composition of the wastewater used were determined for the adsorption processes. Batch adsorption experiment was carried out on COPs and textile wastewater’s mixture to find effects of COP’s dosage, agitation, pH and contact time on the colour, Zinc and Copper’s removal from the wastewater. The adsorption isotherms and kinetic studies were conducted using Langmuir, Freundlich, Pseudo-first-order and Pseudo-second-order models. Findings established that the optimum removal of colour, Zinc and Copper respectively occurred at an adsorbent dosage of 2.5, 0.5 and 3.0 g/100ml, pH of 10, 4 and 2, rotating speed of 100, 250 and 250 rpm, contact time of 40, 60, and 40 mins. The adsorption isotherms revealed only copper adsorption as optimum and well fitted Langmuir isotherm. Pseudo-second-order kinetic model best suited adsorption data of the colour and metal ions with high correlation coefficient (R2) exceeding 0.95. Conclusively, COPs is effective in remediating the colour, copper and zinc from the wastewater, thus, recommended as suitable adsorbent for treatment of textile wastewater


2014 ◽  
Vol 16 (4) ◽  
pp. 676-689 ◽  

<div> <p>In the present study, batch adsorption studies were performed for the removal of malachite green and acid blue 161 dyes from aqueous solutions by varying parameters such as contact time, waste marble dust amount, initial dye concentration and temperature. The equilibrium adsorption data were analyzed by Langmuir, Freundlich and Temkin adsorption isotherm models. The Langmuir and Freundlich adsorption models agree well with experimental data. The pseudo-second order, intraparticle intraparticle diffusion and Elovich kinetic models were applied to the experimental data in order to describe the removal mechanism of dye ions by waste marble dust. The pseudo-second order kinetic was the best fit kinetic model for the experimental data. Thermodynamics parameters such as Δ<em>G</em>, Δ<em>H</em> and Δ<em>S </em>were also calculated for the adsorption processes. The experimental data were used to construct an artificial neural network (ANN) model to predict removal of malachite green and acid blue 161 dyes by waste marble dust. A three-layer ANN, an input layer with four neurons, a hidden layer with 12 neurons, and an output layer with one neuron is constructed. Different training algorithms were tested on the model to obtain the proper weights and bias values for ANN model. The results show that waste marble dust is an efficient sorbent for malachite green dye and ANN network, which is easy to implement and is able to model the batch experimental system.</p> </div> <p>&nbsp;</p>


Author(s):  
Armin Geroeeyan ◽  
Ali Niazi ◽  
Elaheh Konoz

Abstract In the present research, the removal of Basic Orange 2 (BO2) dye using alkaline-modified clay nanoparticles was studied. To characterize the adsorbent, XRD, FTIR, FESEM, EDX, BET and BJH analyses were performed. The effect of the variables influencing the dye adsorption process such as adsorbent dose, contact time, pH, stirring rate, temperature, and initial dye concentration was investigated. Furthermore, the high efficiency of Ni2+ removal indicated that it is possible to remove both dye and metal cation under the same optimum conditions. The experimental data were analyzed by Langmuir and Freundlich isotherm models. Fitting the experimental data to Langmuir isotherm indicated that the monolayer adsorption of dye occurred at homogeneous sites. Experimental data were also analyzed with pseudo-first-order, pseudo-second-order, and intra-particle diffusion kinetic equations for kinetic modeling of the dye removal process. The adsorption results indicated that the process follows a pseudo-second-order kinetic model. The thermodynamic parameters of the dye adsorption process such as enthalpy, entropy, and Gibbs free energy changes were calculated and revealed that the adsorption process was spontaneous and endothermic in nature. The results presented the high potential of the modified nanoclay as a cost-effective adsorbent for the removal of BO2 dye and Ni2+ from aqueous medium.


Author(s):  
O.T. Ogunmodede ◽  
O.L. Adebayo ◽  
A.A. Ojo

Natural clay has been considered as a potential absorbent for removing pollutants from water and waste water. Nonetheless, the effective application of clay for water treatment is limited due to small surface area and presence of net negative surface charge, leading to it low adsorption capacity. The absorption capacity was boosted via intercalation of CaO derived from snail shell (SS). The methylene blue sorption potential, PZC, and the surface area of unmodified clay sample were substantially enhanced by the intercalation process. The process of sorption of MB from solution was analyzed using five different isotherm models (Langmuir, Freundlich, Temkin, Harkins-Jura, and Halsey isotherm equations). The value of the Langmuir monolayer sorption capacity qm (mg/g) increased from 50.12 to 88.71, PZC values increased from 4.50 to 7.40, and the surface area (m2/g) value increased from 27 m2/g to 123 m2/g after the intercalation process. The experimental data were fitted into two kinetic models: Lagergren pseudo-first order and the chemisorptions pseudo-second order. It was observed that chemisorptions pseudo-second order kinetic model described the sorption process with high coefficients of determination (r2) better than pseudo first other kinetic models. The modification caused no change in the clay surficial microstructure but increased the lattice spacing of the clay framework.


2017 ◽  
Vol 23 (4) ◽  
pp. 447-456
Author(s):  
Rahim Shojaat ◽  
Afzal Karimi ◽  
Naghi Saadatjoo ◽  
Soheil Aber

In the present study, GOx/MnFe2O4/calcium alginate nano-composite was prepared by the trapping enzyme/nanoparticles in calcium alginate. The prepared absorbent was applied for decolorization of artificial dye wastewater of acid red 14 (AR14) by heterogeneous bio-Fenton system. Kinetic and isotherm studies were carried out. The decolorization of acid red 14 followed the Michaelis- Menten, pseudo-first order and pseudo-second order kinetic models. Good correlation coefficients were obtained by fitting the experimental data to Michaelis- Menten and pseudo-second order kinetic models. The adsorption isotherms were described by Langmuir, Freundlich and Temkin isotherms. Among the three isotherm models, the Freundlich model was fitted with the equilibrium data obtained from adsorption of AR14 onto MnFe2O4/calcium alginate; while Temkin isotherm gave the best correlation for adsorption on MnFe2O4 nanoparticles. The effect of various parameters such as initial pH of solution, initial dye concentration, and contact time on the adsorption of AR14 on MnFe2O4 and MnFe2O4/ /calcium alginate as well as dye enzymatic decomposition was studied. The decolorization of AR14 with initial concentration of 10 mg.L?1 by using GOx/ /MnFe2O4/calcium alginate was 60.17%.


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