Removal of Methylene Blue from Aqueous Solution by Powdered Expanded Graphite: Adsorption Isotherms and Thermodynamics

2012 ◽  
Vol 424-425 ◽  
pp. 1313-1317 ◽  
Author(s):  
Shui Cheng Tan ◽  
Peng Hui Shi ◽  
Rui Jing Su ◽  
Min Cong Zhu
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Adsorption Isotherms ◽  
Dye Adsorption ◽  
Expanded Graphite ◽  
Solution Ph ◽  
Adsorption Behaviors ◽  
Different Temperatures ◽  
Isotherms And Thermodynamics ◽  
Langmuir And Freundlich Equations

The powdered expanded graphite (EG) was used as a porous adsorbent for the removal of the cationic dye, methylene blue (MB), from aqueous solution. The dye adsorption experiments were carried out with the bath procedure. Adsorption isotherms at different temperatures were determined and modeled with Langmuir and Freundlich equations. Thermodynamic parameters were calculated and correlated with the adsorption behaviors. The effects of solution pH on the adsorption were also studied.

Comparison of Coal Ash and Activated Carbon for Removal of Humic Acid from Aqueous Solution

2013 ◽  
Vol 864-867 ◽  
pp. 1509-1512
Author(s):  
Xue Mei Zhang ◽  
Yan Zhang ◽  
Di Fan
Keyword(s):  
Aqueous Solution ◽  
Humic Acid ◽  
Activated Carbons ◽  
Removal Rate ◽  
Coal Ash ◽  
Cost Effective ◽  
Solution Ph ◽  
Adsorption Behaviors ◽  
Calcium Loading ◽  
Working Solution

This paper presents the adsorption behaviors of humic acid (HA) on coal ashes and powdered activated carbons (PACs). A bituminous coal, with or without calcium-loading, was used as a feedstock for coal ash preparation. The working solution of HA with a concentration of 20 mg/L was used in all adsorption tests. The results showed that calcium-enriched coal ash (CECA) gave rise to the removal rate of HA as high as 84.05%, much higher than those of raw coal ash (RCA) and PACs. The impacts of solution pH and adsorbent dosage on HA adsorption capacity were also investigated. It was found that lower pH facilitated to the removal of HA from aqueous solution by means of CECA, and the optimal CECA dosage was about 1.0g/L at pH 7.00. The data obtained in this study suggested that calcium-enriched coal ash could be useful and cost-effective in the treatment of wastewaters containing HA-like organic macro-molecules.

scholarly journals Study on the adsorption of methylene blue from aqueous solution using hydrogel glucomannan/graphene oxide

2021 ◽  
Vol 10 (1) ◽  
pp. 59-66
Author(s):  
Son Le Lam ◽  
Phu Nguyen Vinh ◽  
Hieu Le Trung ◽  
Tan Le Thua ◽  
Nhan Dang Thi Thanh ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Graphene Oxide ◽  
Adsorption Capacity ◽  
Organic Dyes ◽  
Dye Adsorption ◽  
Order Kinetic ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Glucomannan/graphene oxide (GM/GO) hydrogel was synthesized by using calcium hydroxide as the crosslinker. The synthesized material was characterized by using IR, XRD, SEM, EDX and RAMAN technology. The composite hydrogel was used for removal of organic dyes from aqueous solution. The results showed that the GM/GO hydrogel had a porous structure and a high adsorption capacity toward methylene blue (MB). The pseudo-second-order kinetic model could fit the rate equation of MB adsorption onto the GM/GO hydrogel. The adsorption of MB onto GM/GO hydrogel was a spontaneous process. In addition, the equilibrium adsorption isotherm data indicated that equilibrium data were fitted to the Langmuir isotherm and the maximum dye adsorption capacity was 198,69 mg.g-1. Moreover, the hydrogel was stable and easily recovered and adsorption capacity was around 97% of the initial saturation adsorption capacity after being used five times.

Adsorption of Grape Seed Procyanidins on Macroporous Adsorbent Resin: Isotherms and Thermodynamics

2011 ◽  
Vol 396-398 ◽  
pp. 571-574 ◽  
Author(s):  
Ying Hua Song ◽  
Gui Zhi Zhang
Keyword(s):  
Solid Solution ◽  
Adsorption Isotherms ◽  
Adsorption Process ◽  
Physical Adsorption ◽  
Grape Seed ◽  
Adsorption Properties ◽  
Macroporous Resin ◽  
Solution Interface ◽  
Isotherms And Thermodynamics ◽  
Langmuir And Freundlich Equations

The adsorption properties,including the adsorption isotherms,thermodynamics,of grape seed procyanidins onto macroporous resin HZ818 are investigated.Both the Langmuir and Freundlich equations can provide a good fit to the adsorption isotherms, which indicates an endothermic and a favorable process in our study.The capacities of the adsorption increase with temperature. The negative values of ΔG and values of ΔH lower than 40 kJ/mol indicate a spontaneous physical adsorption, and the positive values of ΔS show the increased randomness at the solid/solution interface during the adsorption process.

scholarly journals Surface Characterization and Thermodynamics of Adsorption of Pr, Nd and Er on Alumina from Aqueous Solution

1992 ◽  
Vol 9 (1) ◽  
pp. 17-29 ◽  
Author(s):  
M. Saleem ◽  
M. Afzal ◽  
F. Mahmood ◽  
A. Ali
Keyword(s):  
Aqueous Solution ◽  
Particle Size ◽  
Free Energy ◽  
Adsorption Isotherms ◽  
Surface Characterization ◽  
Average Particle Size ◽  
Average Particle ◽  
Enthalpy Of Adsorption ◽  
Different Temperatures ◽  
Isotherm Equations

The porous nature of alumina has been investigated using various techniques. The values obtained for moisture content, surface area, pore volume, average particle size and porosity were 22%, 116 m2/g, 0.76 cm3/g, 17.0±0.5 μm and 68.0%, respectively. The adsorption isotherms of NdIII, PrIII and ErIII on alumina from aqueous solution have been obtained at different temperatures. All these adsorption isotherms obey the Langmuir, Freundlich and Dubinin-Radushkevich isotherm equations. Thermodynamic parameters such as the free energy, entropy and enthalpy of adsorption have been computed and interpreted. It is noteworthy that the adsorption of PrIII and NdIII increases with decreasing temperature while the reverse is observed for ErIII.

Removal of methylene blue from aqueous solution by Artist's Bracket fungi: kinetic and equilibrium studies

2016 ◽  
Vol 73 (11) ◽  
pp. 2832-2840 ◽  
Author(s):  
Daryush Naghipour ◽  
Kamran Taghavi ◽  
Mehrdad Moslemzadeh
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Removal Efficiency ◽  
Dye Adsorption ◽  
Surface Characteristic ◽  
Coefficient Of Determination ◽  
Order Kinetic ◽  
Operational Parameters ◽  
Equilibrium Studies ◽  
Increasing Temperature

In this study, adsorption of methylene blue (MB) dye onto Artist's Bracket (AB) fungi was investigated in aqueous solution. Fourier transform infrared and scanning electron microscopy were used to investigate surface characteristic of AB fungi. Influence of operational parameters such as pH, contact time, biosorbent dosage, dye concentration, inorganic salts and temperature was studied on dye removal efficiency. With the increase of pH from 3 to 9, removal efficiency increased from 74.0% to 90.4%. Also, it reduced from 99.8% to 81.8% with increasing initial MB concentration from 25 mg L−1 to 100 mg L−1, whereas it increased from 54.7% to 98.7% and from 98.5% to 99.9% with increasing biosorbent dosage from 0.5 g L−1 to 2 g L−1 and with increasing temperature from 25 °C to 50 °C, respectively. Isotherm studies have shown adsorption of MB dye over the AB fungi had a better coefficient of determination (R2) of 0.98 for Langmuir isotherm. In addition, the maximum monolayer adsorption capacity (qm) was 100 mg g−1. Also, the MB dye adsorption process followed pseudo-second-order kinetic. In general, AB fungi particles can be favorable for removal of MB dye from dye aqueous solution with natural pH and high temperature.

scholarly journals Kinetics, Isotherm and Thermodynamic Studies for Efficient Adsorption of Congo Red Dye from Aqueous Solution onto Novel Cyanoguanidine-Modified Chitosan Adsorbent

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4446
Author(s):  
Nouf F. Al-Harby ◽  
Ebtehal F. Albahly ◽  
Nadia A. Mohamed
Keyword(s):  
Aqueous Solution ◽  
Congo Red ◽  
Adsorption Process ◽  
Ph Value ◽  
Dye Adsorption ◽  
Order Kinetic ◽  
Amino Groups ◽  
Solution Ph ◽  
Intraparticle Diffusion Model ◽  
Modified Chitosan

Novel Cyanoguanidine-modified chitosan (CCs) adsorbent was successfully prepared via a four-step procedure; first by protection of the amino groups of chitosan, second by insertion of epoxide rings, third by opening the latter with cyanoguanidine, and fourth by restoring the amino groups through elimination of the protection. Its structure and morphology were checked using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. The adsorption capacity of CCs for Congo Red (CR) dye was studied under various conditions. It decreased significantly with the increase in the solution pH value and dye concentration, while it increased with increasing temperature. The adsorption fitted to the pseudo-second order kinetic model and Elovich model. The intraparticle diffusion model showed that the adsorption involved a multi-step process. The isotherm of CR dye adsorption by CCs conforms to the Langmuir isotherm model, indicating the monolayer nature of adsorption. The maximum monolayer coverage capacity, qmax, was 666.67 mg g−1. Studying the thermodynamic showed that the adsorption was endothermic as illustrated from the positive value of enthalpy (34.49 kJ mol−1). According to the values of ΔG°, the adsorption process was spontaneous at all selected temperatures. The value of ΔS° showed an increase in randomness for the adsorption process. The value of activation energy was 2.47 kJ mol−1. The desorption percentage reached to 58% after 5 cycles. This proved that CCs is an efficient and a promising adsorbent for the removal of CR dye from its aqueous solution.

scholarly journals Sugarcane Bagasse as an Efficient Biosorbent for Methylene Blue Removal: Kinetics, Isotherms and Thermodynamics

2020 ◽  
Vol 17 (2) ◽  
pp. 526 ◽  
Author(s):  
Thaisa Caroline Andrade Siqueira ◽  
Isabella Zanette da Silva ◽  
Andressa Jenifer Rubio ◽  
Rosângela Bergamasco ◽  
Francielli Gasparotto ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Sugarcane Bagasse ◽  
Adsorption Isotherms ◽  
Low Cost ◽  
Cost Effective ◽  
Blue Dye ◽  
Maximum Adsorption Capacity ◽  
Effective Option ◽  
Pseudo Second Order ◽  
Isotherms And Thermodynamics

Adsorption in biomass has proven to be a cost-effective option for treatment of wastewater containing dyes and other pollutants, as it is a simple and low cost technique and does not require high initial investments. The present work aimed to study the adsorption of methylene blue dye (MB) using sugarcane bagasse (SCB). The biomass was characterized by scanning electron microscopy (SEM). Adsorption studies were conducted batchwise. Kinetics, adsorption isotherms, and thermodynamics were studied. The results showed that SCB presented a maximum adsorption capacity of 9.41 mg g−1 at 45 °C after 24 h of contact time. Adsorption kinetics data better fitted the pseudo-second order model, indicating a chemical process was involved. The Sips’s three-parameter isotherm model was better for adjusting the data obtained for the adsorption isotherms, indicating a heterogeneous adsorption process. The process showed to be endothermic, spontaneous, and feasible. Therefore, it was concluded that SCB presented as a potential biosorbent material for the treatment of MB-contaminated waters.

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