scholarly journals Azo Dye Adsorption onto Cobalt Oxide: Isotherm, Kinetics, and Error Analysis Studies

2021 ◽  
Vol 21 (5) ◽  
pp. 1148
Author(s):  
Hawraa Kassem Hami ◽  
Ruba Fahmi Abbas ◽  
Shireen Abdulmohsin Azeez ◽  
Nedaa Ibrahim Mahdi
Keyword(s):  
Cobalt Oxide ◽  
Physical Adsorption ◽  
Error Function ◽  
Dye Adsorption ◽  
Second Order ◽  
Regression Methods ◽  
Maximum Sorption ◽  
Pseudo Second Order ◽  
Isotherm And Kinetic Models ◽  
The Impact

The current study focused on utilizing cobalt oxide to eliminate hazardous Eriochrome Black T (EBT) dye. The impact of pH (2, 4, 7, 8, and 10) and temperature (45, 50, and 55 °C) was examined for EBT removal. The results show that the maximum sorption occurred at pH = 2 and that the removal percentage increased with increasing temperature. Five non-linear regression methods were used to predict the best isotherm and kinetic models. A coefficient of non-determination, K2, was very helpful for selecting the RMSD function as a preferable error function among the five methods. Isothermal models to illustrate equilibrium sorption information, the Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich models were used. The results showed that the Langmuir model (R2 = 0.99) was the most favorable, indicating monolayer sorption of EBT occurred. The kinetics models were analyzed using pseudo-first-order and pseudo-second-order whereas the sorption information was well described by the pseudo-second-order model (R2 = 0.99). The results of the thermodynamic study appeared that the adsorption of EBT was endothermic, feasible, spontaneous, and physical adsorption.

scholarly journals Application of activated bentonite for the removal of direct and reactive dye from aqueous solutions

2019 ◽  
Vol 25 (4) ◽  
pp. 341-351
Author(s):  
Aleksandar Zdravkovic ◽  
Novica Stankovic ◽  
Nebojsa Ristic ◽  
Goran Petkovic
Keyword(s):  
Aqueous Solutions ◽  
Dye Adsorption ◽  
Bentonite Clay ◽  
Reactive Dye ◽  
Second Order ◽  
Intra Particle Diffusion ◽  
Naoh Solution ◽  
Activated Bentonite ◽  
Endothermic Process ◽  
Pseudo Second Order

The aim of this study was to determine adsorptive properties of acid activated bentonite clay for the removal of Direct Red 173 (DR 173) and Reactive Red 22 (RR 22) dyes from aqueous solutions. Raw and modified clay were characterized by the following methods: Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRPD), and scanning electron microscopy (SEM). The efficiency of activated clay adsorption was investigated depending on process parameters: the adsorbent dose, pH, temperature, initial dye concentration, and contact time. Experimental data were analyzed by Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich isotherm as well as kinetic models of pseudo-first order, pseudo-second order and intra-particle diffusion. The process of dye adsorption was best described by Langmuir, Temkin, and Dubinin-Radushkevich isotherm (R2 > 0.97). Pseudo-second order model (R2 > 0.99) had the highest correlation with the obtained kinetic results. The positive value of ?H? indicated that adsorption of dyes by activated bentonite clay is endothermic process. The activated bentonite exhibited good regenerative ability in the 0.1 M NaOH solution. Maximum adsorption capacities of acid activated bentonite clay at 25?C for DR 173 and RR 22 dyes were 356.65 and 109.58 ?mol g-1, respectively.

scholarly journals Removal of Basic Orange 2 dye and Ni2+ from aqueous solutions using alkaline-modified nanoclay

2021 ◽  
Author(s):  
Armin Geroeeyan ◽  
Ali Niazi ◽  
Elaheh Konoz
Keyword(s):  
Experimental Data ◽  
High Efficiency ◽  
Adsorption Process ◽  
Kinetic Equations ◽  
Dye Adsorption ◽  
Second Order ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Diffusion Kinetic ◽  
Pseudo Second Order

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.

scholarly journals A Study of The Equilibrium, Kinetics, and Thermodynamics of Malachite Green Dye Adsorption Onto Lignin

2021 ◽  
Author(s):  
Vani Gandham ◽  
UMA Addepally ◽  
Bala Narsaiah T
Keyword(s):  
Malachite Green ◽  
Group Analysis ◽  
Dye Adsorption ◽  
Second Order ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Adequate Treatment ◽  
Pseudo Second Order ◽  
Kinetics And Isotherms

Abstract Malachite Green (MG), a cationic synthetic dye is considered hazardous when discharged into the water bodies without any adequate treatment. It can affect the multiple segments of the environment leading to irreversible persistent changes. So, there is a need for remediation with cost-effective method to remove dyes from effluents. Adsorption is one such technique to remove dyes from wastewater and is effective and economical. The present study describes the removal of MG cationic dye from wastewater using eco-friendly and biodegradable lignin extracted from hydrothermally treated rice straw by adsorption process. Functional group analysis and morphological characterisation was done to the extracted lignin after quantification. The maximum percent removal of MG 92 ± 0.2 % was observed from a series of batch experiments at optimum process parameters of: contact time 80 min, initial dye concentration 50 ppm, lignin dosage 0.25g, pH 7, temperature 300c and with 100 rpm agitation speed. The adsorption kinetics and isotherms were determined for the experimental data using four kinetic models (pseudo-first-order, second order, pseudo-second-order and intra-particle diffusion model) and two isotherm models (Langmuir and Freundlich). The results suggested that the kinetics data fit to the pseudo-second-order kinetic model with the maximum adsorption capacity 36.7 mg/g and the two isotherm models were applicable for the adsorption of MG onto the lignin. Additionally, the thermodynamic parameters ΔSo, ΔHo and ΔGo were evaluated. Therefore, lignin which is an environmental friendly and low cost carbon material that can be used as an adsorbent for dye removal.

scholarly journals Crystal Violet Dye Adsorption from Aqueous Solution using Activated Chickpea Husk (Cicer arientum)

2021 ◽  
Vol 34 (1) ◽  
pp. 104-110
Author(s):  
Sonia Rani ◽  
Sudesh Chaudhary
Keyword(s):  
Crystal Violet ◽  
Adsorption Mechanism ◽  
Dye Adsorption ◽  
Second Order ◽  
Order Model ◽  
Batch Mode ◽  
After Effects ◽  
Crystal Violet Dye ◽  
Pseudo Second Order ◽  
Second Order Model

The chickpea husk (Cicer arientum) were activated by chemical modification with sulphuric acid, for its application as biosorbent for the remediation of crystal violet dye from wastewater. Activated chickpea husk (ACH) was characterized for its chemical structure and morphology using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). The after effects of leading affecting parameters like dose of adsorbent, time of contact, pH and concentration were studied by commencing experiments in batch mode. Adsorption mechanism and sorption efficiency of ACH was examined using variety of isotherms (Langmuir & Freundlich) and kinetic models (pseudo first order and pseudo second order). Experimental data for adsorption rate was in good harmony with the results obtained using pseudo second order model. The adsorption capacity determined using Langmuir isotherm and pseudo second order model was found to be 142.85 mg/g.

scholarly journals Transformation of residual biomass into adsorbent materials: Applications to treatment of liquid effluents

2019 ◽  
Vol 9 (1) ◽  
pp. 1-11
Author(s):  
Samia Glissi ◽  
Meriem Tarbaoui ◽  
Laila Makouki ◽  
Khadija Legrouri ◽  
Hassan Hannache ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Phosphoric Acid ◽  
Correlation Coefficient ◽  
Chemical Activation ◽  
Second Order ◽  
Order Kinetic ◽  
Residual Biomass ◽  
Pseudo Second Order ◽  
The Impact ◽  
Adsorbent Materials

In this work, some adsorbent materials were prepared from residual biomass, which constitutes a real hazard for the environment and human health. So, in order to valorize this vegetal resource, a process of transformation was studied. The residual biomass was turned into adsorbent materials under the effect of chemical activation with phosphoric acid which allows the development of a large pore in the activated materials. The optimization of the conditions for the elaboration of our adsorbents was realized by experimental design by evaluating some parameters (percentage of phosphoric acid, temperature and time of activation) and their effects on the responses (capacity of adsorption of methylene blue, adsorbent yield), these parameters were selected after a screening study. The activation of our residual biomass was effected with 60% of phosphoric acid in 225°C while 115 min. The studied biomass was characterized by different physic-chemical methods (Differential Thermal Analysis /Thermogravimetric Analysis (DTA/TGA), Scanning Electron Microscopy (SEM), Raman and X-Ray Diffraction (XRD)); the results of characterization show the presence of the excellent textural and structural properties. The application of the best adsorbent in the removal of textile dyes (methylene blue) from aqueous solutions was studied. The impact of various parameters such as contact time, pH and concentration on the removal was evaluated by batch method. The adsorption isotherms were studied using Langmuir and Freundlich isotherm models. Langmuir isotherm provided the best fit to the equilibrium data with a correlation coefficient equal to 0.998. This result shows the presence of monolayer adsorption. The experiments demonstrated that the removal of methylene blue followed the pseudo-second-order kinetic model. The correlation coefficient is consistent and equal to unity, and the experimental qe value (44.17) was agreed with the calculated qe value (45.45) of pseudo-second-order then the value of pseudo-first-order which confirm a chemisorption process. The obtained results revealed that the elaborated material is an effective adsorbent for the removal of methylene blue.

scholarly journals Polyvinyl Alcohol/Calcium Carbonate Nanocomposites as Efficient and Cost-Effective Cationic Dye Adsorbents

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2179
Author(s):  
Davoud Jahani ◽  
Amin Nazari ◽  
Jaber Ghourbanpour ◽  
Amir Ameli
Keyword(s):  
Calcium Carbonate ◽  
Polyvinyl Alcohol ◽  
Adsorption Kinetics ◽  
Dye Removal ◽  
Dye Adsorption ◽  
Second Order ◽  
Order Kinetic ◽  
Cationic Dye ◽  
Intraparticle Diffusion Model ◽  
Pseudo Second Order

A novel polyvinyl alcohol (PVA)/calcium carbonate-based double-layer cationic dye adsorbent was developed. Polyvinyl alcohol (50 wt %) and calcium carbonate (50 wt %) were used together with borax as a cross-linking agent. The nanocomposite was prepared using only water, without the need for any toxic solvent or hazardous chemical. The final samples were obtained by the solvent casting method. The nanocomposite adsorbent was characterized using a Fourier transform infrared (FTIR) spectroscope and a scanning electron microscope (SEM). The adsorption performance on two cationic dyes, i.e., methylene blue and safranin was studied. Dye adsorption was quantified by measuring the nanocomposite swelling, contact time, and dye concentration. Pseudo first-order and pseudo second-order kinetic models as well as intraparticle diffusion model were used to model the adsorption kinetics. Moreover, the isotherm dye adsorption was investigated by Langmuir and Freundlich models. The results revealed that the developed nanocomposite has relatively high adsorption efficiency and short adsorption time and retains its performance after several successive absorption–desorption processes. The results also showed that the pseudo-second-order model best describes the adsorption kinetics, and the Freundlich isotherm model has a better compatibility with the experimental data. Finally, an adsorption mechanism was proposed for the dye removal process. The developed PVA/CaCO3 nanocomposite can be potentially used for efficient dye removal in wastewater treatments.

Adsorption Kinetics of Lignite Activated Carbon in Treating Coal Gasification Wastewater

2014 ◽  
Vol 1073-1076 ◽  
pp. 955-959
Author(s):  
Ruo Zheng Li ◽  
Hong Yang ◽  
Xin Jin
Keyword(s):  
Activated Carbon ◽  
Coal Gasification ◽  
Adsorption Process ◽  
Physical Adsorption ◽  
Second Order ◽  
Pseudo Second Order ◽  
Coal Gasification Wastewater ◽  
New Treatment ◽  
Kinetics Of ◽  
Adsorption Activation Energy

Lignite activated carbon was provided through lignite which is treated specially. The adsorption capacity and mechanism of COD from Coal gasification wastewater by lignite activated carbon have been studied.The adsorption capacities of lignite activated carbon at different times were obtained by concentration of COD in the remainder solution. Three simplified kinetic models: pseudo-first-order, pseudo-second-order, intraparticle diffusion equations were adopted to examine the mechanism of the adsorption process. The results showed that the adsorption can be expressed by the pseudo-second-order model. The adsorption balance capacity was obtained as 50.8mg·g-1 (298K), and the adsorption balance capacity decreased with increasing of temperature, which showed that the adsorption process was exothermic. The adsorption activation energy (Ea) was calculated as 5.76kJ·mol-1, and it showed that the adsorption process was Physical adsorption. This study explored new treatment channels for lignite comprehensive utilization..

Kinetic Study and Equilibrium Isotherm Analysis of Cationic Dye Adsorption onto Attapulgite and Rectorite

2012 ◽  
Vol 446-449 ◽  
pp. 2960-2963
Author(s):  
Jing Yan Song ◽  
Jing Yang
Keyword(s):  
Low Cost ◽  
Dye Adsorption ◽  
Second Order ◽  
Order Kinetic ◽  
Cationic Dye ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Langmuir And Freundlich Equations

The adsorption properties of the attapulgite and the rectorite were investigated by removal of a cationic dye, methylene blue (MB) from aqueous solution. The attapulgite and the rectorite were characterized by Fourier transform infrared (FT-IR) spectroscopy, Brunauer-Emmett-Teller (BET) and scanning electron microscopy (SEM). The analysis of the isotherm equilibrium data using the Langmuir and Freundlich equations showed that the data fitted better with Langmuir model. Pseudo-first-order and pseudo-second-order models were considered to evaluate the rate parameters. The experimental data were well described by the pseudo-second-order kinetic model. The results indicate that the attapulgite exhibited higher adsorption capacity for MB than rectorite and could be employed as a low-cost alternative in wastewater treatment for the removal of cationic dyes.

scholarly journals Investigation of the removal of Ni(II) from aqueous solution using pomelo fruit peel

2021 ◽  
Vol 63 (2) ◽  
pp. 7-12
Author(s):  
Van Phuc Dinh ◽  
Keyword(s):  
Kinetic Models ◽  
Second Order ◽  
Order Kinetic ◽  
Fruit Peel ◽  
First Order ◽  
Pseudo Second Order ◽  
Three Stages ◽  
Isotherm And Kinetic Models ◽  
Major Factors ◽  
Better Than

Pomelo fruit peel, an organic waste, was utilised as a biosorbent to remove Ni(II) from aqueous solutions. Some major factors influencing Ni(II) uptake such as pH, adsorption time, and initial Ni(II) concentration were examined. Several isotherm and kinetic models including the Langmuir, Freundlich, Sips, pseudo-first-order, pseudo-second-order, and intra-diffusion models were fit to the experimental data. Results showed that the Ni(II) uptake obtained an equilibrium at pH=6 after 80 min at 303 K. The Sips isotherm model described the Ni(II) adsorption better than other models and the monoadsorption capacity calculated from the Langmuir model was 9.67 mg/g. The adsorption of Ni(II) followed pseudo-second-order kinetic models with three stages.

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