scholarly journals Decolorization of Malachite green dye from wastewater by Populus deltoides: three-level Box–Behnken design optimization, equilibrium, and kinetic studies

2015 ◽  
Vol 5 (3) ◽  
pp. 250-263 ◽  
Author(s):  
Afsaneh Shahbazi ◽  
Farnoosh Bagheri Zonoz
Keyword(s):  
Malachite Green ◽  
Populus Deltoides ◽  
Kinetic Studies ◽  
Second Order ◽  
Coefficient Of Determination ◽  
P Value ◽  
Box Behnken Design ◽  
Malachite Green Dye ◽  
Initial Ph ◽  
Adsorbent Dose

Decolorization of Malachite green in aqueous solution by adsorption onto Populus deltoides sawdust (PSD) was optimized through a four-factor, three-level Box–Behnken design in response surface methodology. The influences of four independent variables such as initial pH of solution (3–7), dye concentration (50–300 mg/L), adsorbent dose (0.2–2 g/L), and temperature (23–50 °C) were studied to optimize the condition of dye removal. A natural log transformation was suggested by the Box–Cox plot in order to enhance the model significance. Regression analysis showed good fit of the experimental data to the second-order polynomial model with high coefficient of determination values (R2 = 0.996; Radj.2 = 0.9913; Rpred.2 = 0.9769), F-value of 213.03, and p-value of <0.0001 (α = 0.05). Under optimum values of all the four variables, viz., pH of 6.02, initial dye concentration of 262.6 mg/L, adsorbent dose of 0.23 g/L and temperature of 30.3 °C, the maximum uptake (qe) was noted to be 920.9 mg/g. The experimental equilibrium adsorption data were fitted well to the Langmuir isotherm model (R2 = 0.9949). Kinetic studies revealed that adsorption followed pseudo-second order. It was found that PSD is suitable for reuse four times in successive adsorption-desorption cycles with loss of 25.2% in adsorption capacity.

scholarly journals Removal of Malachite Green from Aqueous Solution by Activated Carbon Developed from Cocoa (Theobroma Cacao) Shell - A Kinetic and Equilibrium Studies

2011 ◽  
Vol 8 (s1) ◽  
pp. S363-S371 ◽  
Author(s):  
C. Theivarasu ◽  
S. Mylsamy
Keyword(s):  
Experimental Data ◽  
Activated Carbon ◽  
Malachite Green ◽  
Kinetic Models ◽  
Theobroma Cacao ◽  
Second Order ◽  
Order Kinetic ◽  
Equilibrium Studies ◽  
Initial Ph ◽  
Pseudo Second Order

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.

scholarly journals Application of Factorial Design for the Optimization of Hexavalent Chromium Removal Using a New Low-cost Adsorbent: Adsorption Isotherms, Thermodynamic and Kinetic Studies

2021 ◽  
Vol 12 (1) ◽  
pp. 1247-1262
Keyword(s):  
Aqueous Solution ◽  
Activated Carbon ◽  
Experimental Design ◽  
Hexavalent Chromium ◽  
Low Cost ◽  
Research Work ◽  
Kinetic Studies ◽  
Factorial Experimental Design ◽  
Initial Ph ◽  
Adsorbent Dose

This research work involved using factorial experimental design techniques to investigate the adsorption of hexavalent chromium from an aqueous solution on medlar activated carbon. A 24 full factorial experimental design was employed to determine the optimum values and degree of importance of parameters: pH, initial Cr (VI) concentration, adsorbent dose, and contact time at two levels. The optimized conditions for hexavalent chromium Cr (VI) removal were at initial pH 1.5, 5 mg.L−1Cr (VI), adsorbent dose 6 mg, and 60 min adsorption time. The results predicted a good agreement between the predicted values (R2= 0.9909), as obtained by the model, and the experimental value (R2= 0.9977). The main effects and interaction effects were analyzed using analysis of variance (ANOVA), F-test and P-values to define the most important process variables affecting Cr (VI) adsorption. The most significant variables were therefore the pH of the solution and the adsorbent dose. Therefore, the present results demonstrate that medlar activated carbon should be regarded as a low-cost alternative for removing Cr (VI) from an aqueous solution. The adsorption data were evaluated by Langmuir, Freundlich, and Dubinin-Radushkevich isotherms. The results showed that the Langmuir isotherm model best describes the equilibrium adsorption with a high correlation coefficient.

scholarly journals Optimization of electrocoagulation operating parameters for COD removal from olive mill wastewater: application of Box-Behnken design

2019 ◽  
Vol 9 (3) ◽  
pp. 212-221
Author(s):  
Fatima Erraib ◽  
Khalid El Ass
Keyword(s):  
Response Surface ◽  
Chloride Concentration ◽  
Oxygen Demand ◽  
Olive Mill Wastewater ◽  
Operating Conditions ◽  
Cod Removal ◽  
Coefficient Of Determination ◽  
Box Behnken Design ◽  
Initial Ph ◽  
Olive Mill

Box–Behnken response surface design was successfully employed to optimize and study the olive mill wastewater (OMW) treatment by electrocoagulation (EC) process. The influence of four decisive factors were modelled and optimized to increase the removal of chemical oxygen demand (COD). The Box–Behnken design (BBD) results were analyzed and the second-order polynomial model was developed using multiple regression analysis. The model developed from the experimental design was predictive and a good fit with the experimental data with a high coefficient of determination (R2 ) value (more than 0.98). The optimal operating conditions based on Derringer’s desired function methodology are found to be; initial pH of 4.4, a current density of 27.6 mA/cm2 , electrolysis time of 14.1 min, and chloride concentration of 3.2 g/L. Under these conditions, the predicted COD removal efficiency was found to be 67.14% with a desirability value of 0.94. These experimental results were confirmed by validation experiments and proved that Box–Behnken design and response surface methodology could efficiently be applied for modelling of COD removal from OMW.

Kinetic Studies of Adsorption of Disperse Blue 2BLN from Aqueous Solution by Expanded Graphite

2011 ◽  
Vol 148-149 ◽  
pp. 357-360
Author(s):  
Jin Bo Huang ◽  
Min Cong Zhu ◽  
Zhi Fang Zhou ◽  
Hong Xia Zhang
Keyword(s):  
Aqueous Solution ◽  
Room Temperature ◽  
Ph Value ◽  
Expanded Graphite ◽  
Kinetic Studies ◽  
Second Order ◽  
Batch Adsorption ◽  
Initial Ph ◽  
Intra Particle Diffusion ◽  
Pseudo Second Order

Expanded graphite (EG) was prepared by microwave irradiation and evaluated as adsorbent for the removal of disperse blue 2BLN (DB) from aqueous solution by the batch adsorption technique under different conditions of initial pH value, adsorbent dosage, initial dye concentration and contact time. The experimental data were analyzed considering pseudo-first-order, pseudo-second-order and intra-particle diffusion approaches. The adsorption kinetics at room temperature could be expressed by the pseudo second order model very well. The results indicate that the adsorption rate is fast enough and more than eighty percent of the adsorbed DB can be removed in the first 15 min at room temperature, which makes the process practical for industrial application.

Exclusion of Organic Dye Using Neoteric Activated Carbon Prepared from Cornulaca monacantha Stem: Equilibrium and Thermodynamics Studies

2016 ◽  
Vol 875 ◽  
pp. 1-15 ◽  
Author(s):  
Arush Sharma ◽  
Gaurav Sharma ◽  
Amit Kumar ◽  
Zia Mahmood Siddiqi ◽  
Gaurav Sharma
Keyword(s):  
Activated Carbon ◽  
Malachite Green ◽  
Low Cost ◽  
Entropy Change ◽  
Sorption Process ◽  
Second Order ◽  
Adsorption Parameters ◽  
Malachite Green Dye ◽  
Endothermic Process ◽  
Pseudo Second Order

In this study, Cornulacamonacantha stem (CMS) has been used for the preparation of highly competent, ecofriendly and low-cost activated carbon (CMSAC) biosorbent. It was characterized by some instrumental techniques such as Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). The biosorbent was evaluated for the eradication of hazardous malachite green (MG) dye from aqueous solution. Batch experiments were conducted to assess the effect of various adsorption parameters such initial dye concentration, sorbent dosage, pH, agitation time and temperature. The results indicated that maximum sorption of MG was occurred at the pH ranged from 10.0 to 12.0. Langmuir, Freundlich and Tempkin isotherms were applied for the interpretation of experimental data and Langmuir model was found to be strongly fitted with higher R2 (0.999). The kinetics studies were examined using pseudo-first-order, pseudo-second-order, Elovich model. The sorption process was described by pseudo-second-order kinetics. The thermodynamic parameters such as energy change (ΔG°), enthalpychange (ΔH°) and entropy change (ΔS°) were found to be-6.21kJ/mol, 46.17 kJ/mol and 172.81 J/mol/K, respectively. The adsorption performance of malachite green dye onto gleaming activated carbon developed from Cornulacamonacantha stem was found to be spontaneous, feasible and endothermic process.

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