scholarly journals Preparation and Characterization of Chitosan/Feldspar Biohybrid as an Adsorbent: Optimization of Adsorption Process via Response Surface Modeling

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Maryam Yazdani ◽  
Hajir Bahrami ◽  
Mokhtar Arami
Keyword(s):  
Response Surface ◽  
Adsorption Process ◽  
Dye Adsorption ◽  
Surface Modeling ◽  
Quadratic Model ◽  
Response Surface Modeling ◽  
Prediction Errors ◽  
Order Kinetic ◽  
Order Kinetic Model ◽  
Process Factors

Chitosan/feldspar biobased beads were synthesized, characterized, and tested for the removal of Acid Black 1 dye from aquatic phases. A four-factor central composite design (CCD) accompanied by response surface modeling (RSM) and optimization was used to optimize the dye adsorption by the adsorbent (chitosan/feldspar composite) in 31 different batch experiments. Independent variables of temperature, pH, initial dye concentration, and adsorbent dose were used to change to coded values. To anticipate the responses, a quadratic model was applied. Analysis of variance (ANOVA) tested the significance of the process factors and their interactions. The adequacy of the model was investigated by the correlation between experimental and predicted data of the adsorption and the calculation of prediction errors. The results showed that the predicted maximum adsorption amount of 21.63 mg/g under the optimum conditions (pH 3, temperature 15°C, initial dye concentration 125 mg/L, and dose 0.2 g/50 mL) was close to the experimental value of 19.85 mg/g. In addition, the results of adsorption behaviors of the dye illustrated that the adsorption process followed the Langmuir isotherm model and the pseudo-second-order kinetic model. Langmuir sorption capacity was found to be 17.86 mg/g. Besides, thermodynamic parameters were evaluated and revealed that the adsorption process was exothermic and favourable.

Bisphenol S adsorption with activated carbon prepared from corncob: optimization using response surface methodology

2020 ◽  
Vol 18 (4) ◽  
Author(s):  
Xiangyang Zhang ◽  
Xiuli Han ◽  
Chun Chang ◽  
Pan Li ◽  
Hongwei Li ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Activated Carbon ◽  
Response Surface ◽  
Adsorption Process ◽  
Order Kinetic ◽  
Bisphenol S ◽  
Monolayer Adsorption ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Parameters Analysis

AbstractActivated carbon derived from raw corncob (CCAC), which prepared with steam as the activating agent, was used to adsorb bisphenol S (BPS) from aqueous solution. Characterizations of CCAC were measured by using the Brunauer-Emmett-Teller, scanning electron microscopy, and Fourier transform infrared spectroscopy. Adsorption conditions including initial BPS concentration, contact time, adsorbent dosage and pH were optimized by response surface methodology (RSM). The results show that adsorption equilibrium was well described by the Langmuir and Koble–Corrigan models. The maximum monolayer adsorption capacity of BPS was found to be 617.29 mg g−1 at 298 K. Based on the thermodynamic parameters analysis, the BPS adsorption process was turned out to be spontaneous and exothermic. The adsorption process of BPS was well described by the pseudo-second-order kinetic model. It also found that H-bonding, π–π interaction, and electrostatic interaction were the main mechanisms in the process of BPS adsorption onto the CCAC.

Adsorption onto MWCNTs Coupled with Cloud Point Extraction for Dye Removal from Aqueous Solutions: Optimization by Experimental Design

2020 ◽  
Vol 23 ◽  
Author(s):  
Fariba Safa ◽  
Bahare Osaghi
Keyword(s):  
Aqueous Solutions ◽  
Response Surface ◽  
Cloud Point ◽  
Cloud Point Extraction ◽  
Organic Dyes ◽  
Surface Modeling ◽  
Quadratic Model ◽  
Response Surface Modeling ◽  
Solution Ph ◽  
Input Variables

Aims: The main aim of the study was to examine the feasibility and benefits of adsorption onto multi-walled carbon nanotubes (MWCNTs) coupled with cloud point extraction (CPE) for removal of Rhodamine B (RB) from aqueous solutions. Background: MWCNTs offer the particular features of the ideal adsorbents for the organic dyes such as hollow tubular structure and specific surface area. Nevertheless, they suffer from the drawbacks of low dispersion in the aqueous solutions and separation inconvenience from the media. Cloud point extraction combined with the adsorption onto MWCNTs can be a promising method to overcome the problems. Objective: In the study, adsorption onto MWCNTs coupled with CPE was applied for RB removal from aqueous solutions. The process was optimized by the response surface modeling method. Moreover, applicability of the proposed method in the real sample analyses was investigated. Method: MWCNTs were used as adsorbent and Triton X-100 (TX-100) as the nonionic surfactant for CPE process. The experiments were carried out based on a Box-Behnken design (BBD) with the input variables of MWCNTs dosage (0.6-1.2 mg), solution pH (3–9), clouding time (20-40 min) and TX-100 concentration (10-20 v/v%) using 5 mg L-1 RB solutions. Result: Regression analyses resulted in a statistically significant quadratic model (R2=0.9718, F=24.96, p<0.0001) by which the optimum levels of the variables were predicted as: MWCNTs dosage of 0.7 mg, pH=3, clouding time of 39.9 minutes and TX-100 concentration of 19.91% (v/v). The predicted conditions was experimentally validated by achieving a RB removal of 94.24%. Conclusion: Based on the results, the combination of the environmentally friendly technique of CPE with adsorption onto MWCNTs allows the efficient removal of RB from water samples and the method can be effectively optimized by the response surface modeling.

scholarly journals ZnO, CuO and Fe2O3 green synthesis for the adsorptive removal of direct golden yellow dye adsorption: kinetics, equilibrium and thermodynamics studies

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Saima Noreen ◽  
Safa Ismail ◽  
Sobhy M. Ibrahim ◽  
Heri S. Kusuma ◽  
Arif Nazir ◽  
...  
Keyword(s):  
Adsorption Process ◽  
Dye Adsorption ◽  
Solution Temperature ◽  
Order Kinetic ◽  
First Order ◽  
Green Route ◽  
Golden Yellow ◽  
Exothermic Process ◽  
Order Kinetic Model ◽  
Adsorbent Dose

AbstractIn the present investigation, ZnO, CuO and Fe2O3 were prepared via green route and utilized for the sequestration of DGY (Direct Golden Yellow) dye. Affecting variables i.e., temperature, contact time, adsorbent dose and pH were optimized for maximum sequestration of dye from aqueous medium. The pH 2, adsorbent dose 0.1 g/50 mL dye solution, temperature 30 °C and 50 mg/L dye initial concentration were best levels for efficient dye adsorption and equilibrium was attained in 30 min reaction time. The dye sequestration on to ZnO, CuO and Fe2O3 was an exothermic process. Freundlich and Temkin adsorption isotherms explained well the dye adsorption onto nanoadsorbents and dye adsorption followed pseudo first order kinetic model. Effect of electrolytes and heavy metal ions was also investigated and both affected the adsorption process significantly. In the presences of surfactant/detergent, the removal of dye was reduced and 0.5 N NaOH efficiently desorbed the dye from nanoadsorbents. Findings depicted that the nanoadsorbents are effectual for the sequestration of DGY dye, which can be employed for the remediation of textile effluents.

scholarly journals Kinetics and optimization on discoloration of dyeing wastewater by schorl-catalyzed fenton-like reaction

2014 ◽  
Vol 79 (3) ◽  
pp. 361-377 ◽  
Author(s):  
Huan-Yan Xu ◽  
Wei-Chao Liu ◽  
Shu-Yan Qi ◽  
Yan Li ◽  
Yuan Zhao ◽  
...  
Keyword(s):  
Response Surface ◽  
Reaction Rate Constant ◽  
Second Order ◽  
Order Kinetic ◽  
Reaction Conditions ◽  
Design And Optimization ◽  
Order Kinetic Model ◽  
Kinetic Investigations ◽  
The Relationship ◽  
Experimental Design And Optimization

Kinetics and optimization on the discoloration of an active commercial dye, Argazol Blue BFBR (ABB) by heterogeneous Fenton-like reaction catalyzed by natural schorl were investigated in this study. Kinetic investigations revealed that the first-order kinetic model was more favorable to describe the discoloration of ABB at different reaction conditions than the second-order and Behnajady-Modirshahla-Ghanbery models. The relationship between the reaction rate constant k and reaction temperature T followed the Arrhenius equation, with the apparent activation energy Ea of 51.31kJ?mol-1. The central composite design under the response surface methodology was employed for the experimental design and optimization of the ABB discoloration process. The significance of a second order polynomial model for predicting the optimal values of ABB discoloration was evaluated by the analysis of variance and 3D response surface plots for the interactions between two variables were constructed. Then, the optimum conditions were determined.

Effects of tall fescue biochar on the adsorption behavior of desethyl-atrazine in different types of soil

BioResources ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. 3575-3595
Author(s):  
Wanting Li ◽  
Ruifeng Shan ◽  
Yuna Fan ◽  
Xiaoyin Sun
Keyword(s):  
Tall Fescue ◽  
Adsorption Process ◽  
Exothermic Reaction ◽  
Equilibrium Concentration ◽  
Black Soil ◽  
Adsorption Behavior ◽  
Order Kinetic ◽  
Isothermal Adsorption ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Desethyl-atrazine (DEA) is a metabolite of atrazine that exerts a considerable influence on the environment. In this study, tall fescue biochar was prepared by pyrolysis at 500 °C, and batch experiments were conducted to explore its effect on the adsorption behavior of DEA in red soil, brown soil, and black soil. The addition of biochar increased the equilibrium amount of DEA adsorption for the three soil types. A pseudo-second-order kinetic model most closely fit the DEA adsorption kinetics of the three soils with and without biochar, with a determination coefficient (R2) of 0.962 to 0.999. The isothermal DEA adsorption process of soils with and without biochar was optimally described by the Freundlich and Langmuir isothermal adsorption models with R2 values of 0.98 and above. The DEA adsorption process in the pristine soil involved an exothermic reaction, which became an endothermic reaction after the addition of biochar. Partitioning was dominant throughout the entire DEA adsorption process of the three pristine soils. Conversely, in soils with biochar, surface adsorption represented a greater contribution toward DEA adsorption under conditions of low equilibrium concentration. The overall results revealed that the tall fescue biochar was an effective adsorbent for DEA polluted soil.

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