Caffeine Removal by Adsorption: Kinetics, Equilibrium Thermodynamic and Regeneration Studies

2021 ◽  
Vol 47 (1) ◽  
pp. 95-103
Author(s):  
Ivone Vanessa Jurado Dávila ◽  
Júlia Viola Matzenbacher Hübner ◽  
Keila Guerra Pacheco Nunes ◽  
Liliana Amaral Féris
Keyword(s):  
Adsorption Equilibrium ◽  
Isotherm Models ◽  
Equilibrium Thermodynamic ◽  
Reversible Process ◽  
Experimental Conditions ◽  
First Order ◽  
Equilibrium Data ◽  
Pseudo Second Order ◽  
Adsorption Equilibrium Data ◽  
Influence Of Ph

In this work, it was studied the caffeine removal through the adsorption on granular activated carbon (CAG). The influence of pH, contact time and CAG dosage were analyzed by batch experiments. Adsorption Kinetic was studied using the models of pseudo-first-order and pseudo-second-order. The adsorption equilibrium data was studied with Langmuir, Freundlich, and Redlich-Peterson isotherm models. The process thermodynamic also was studied. It was obtained 88 % of removal under the experimental conditions of natural pH, 60 min of adsorption and 8 g.L-1 of CAG. The kinetic model that showed the best results was the pseudo-secondorder and Langmuir was the isotherm model that best described the adsorption behavior. The thermodynamic parameters obtained showed a spontaneous, endothermic and reversible process. The desorption efficiency also was studied by regenerant solvents. The best results were obtained using a solvent combination of ethyl acetate, ethanol, and water (50:25:25), and it was obtained a caffeine removal of 57 %, achieving 70 % when a new solution is used in each regeneration step.

scholarly journals COMPARISON OF STINGING NETTLE ADSORPTION PERFORMANCE TOWARDS ANIONIC AND CATIONIC DYES

2021 ◽  
Vol 55 (9-10) ◽  
pp. 1131-1142
Author(s):  
BENGÜ ERTAN ◽  
Keyword(s):  
Adsorption Process ◽  
Adsorption Equilibrium ◽  
Maximum Adsorption Capacity ◽  
Order Model ◽  
Stinging Nettle ◽  
First Order ◽  
Equilibrium Data ◽  
Pseudo Second Order ◽  
Adsorption Equilibrium Data ◽  
Cr Uptake

Stinging nettle was used as lignocellulosic adsorbent for the removal of cationic dye – malachite green (MG), and anionic dye – Congo red (CR), from aqueous solution, without any chemical pretreatment. The adsorption equilibrium data fitted well with the Langmuir model for the adsorption of both dyes, with the calculated maximum adsorption capacity of 270.27 mgg-1 and 172.14 mgg-1 for MG and CR, respectively. The adsorption process was controlled by the pseudo-second-order model in the adsorption of MG and by the pseudo-first-order model in the adsorption of CR. The thermodynamics modelling displayed that the process was spontaneous and endothermic. The π–π electron–donor interaction, hydrogen bonds and pore diffusion may also be effective, besides electrostatic interaction between the adsorbate and the adsorbent in the mechanism of MG and CR uptake.

Adsorption of Methylene Blue (MB) Dye in Wastewater by Electrospun Polysulfone (PSF)/Organo-Montmorillonite (O-MMT) Nanostructured Membrane

2018 ◽  
Vol 916 ◽  
pp. 120-124 ◽  
Author(s):  
Ruth R. Aquino ◽  
Marvin S. Tolentino ◽  
Bianca Mae Z. Crisogono ◽  
Sarah Katrina V. Salvacion
Keyword(s):  
Adsorption Equilibrium ◽  
Order Kinetic ◽  
Adsorption Efficiency ◽  
Time Intervals ◽  
First Order ◽  
Equilibrium Data ◽  
Pseudo Second Order ◽  
Absorbance Reading ◽  
Simulated Wastewater ◽  
Adsorption Equilibrium Data

In this study, organo-montmorillonite was utilized as an additive for the fabrication of the nanostructured membrane via electrospinning process.The purpose of this study is to investigate the performance of 95% PSF and 5% O-MMT blend in terms of its adsorption capacity towards MB dye in wastewater and comparing it to pure PSF membranes. Pure PSF and 5% O-MMT blend were immersed in the simulated wastewater at different time intervals (1, 5, 12, 24 and 48 hours), and the change in MB dye concentration was observed by UV-Vis absorbance reading. To determine the mechanism of adsorption, the data obtained were subjected to pseudo-first order and pseudo-second order kinetic models, and were fitted to Langmuir, Freundlich and Temkin adsorption isotherms to determine the adsorption equilibrium data. The results show that the adsorption efficiency was improved by 5.32%.

scholarly journals Adsorption isotherm and thermodynamic studies of As(III) removal from aqueous solutions using used cigarette filter ash

2019 ◽  
Vol 9 (8) ◽  
Author(s):  
Pezhman Zein Al-Salehin ◽  
Farid Moeinpour ◽  
Fatemeh S. Mohseni-Shahri
Keyword(s):  
Aqueous Solutions ◽  
Langmuir Isotherm ◽  
Adsorption Equilibrium ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Cigarette Filter ◽  
Electron Microscopy Analysis ◽  
Equilibrium Data ◽  
Thermodynamic Variables ◽  
Adsorption Equilibrium Data

Abstract In the present paper, used cigarette filter ash was prepared and used as an active adsorbent to remove As(III) ions from aqueous solutions. The prepared adsorbent structure was identified by scanning electron microscopy analysis, Brunauer–Emmett–Teller method and energy-dispersive X-ray spectroscopy analysis. The influence of contact time, pH, adsorbent dose and initial concentration of As(III) on the removal of As(III) was assessed. Several isotherm models were checked to illustrate the adsorption equilibrium. The adsorption equilibrium data adapted well with the Langmuir isotherm model. The maximum adsorption capacity of 33.33 mg/g was acquired from the Langmuir isotherm. The calculated thermodynamic variables verified that the adsorption process is spontaneous and endothermic.

Adsorption Equilibrium and Kinetics of Copper from Aqueous Solutions on Steel Slag

2011 ◽  
Vol 354-355 ◽  
pp. 33-36
Author(s):  
Jian Yun Li ◽  
Quan Xian Hua ◽  
Jun Ling Niu ◽  
Jian Wei Tang ◽  
Ke Xu
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Equilibrium ◽  
Steel Slag ◽  
Adsorption Rate ◽  
Batch Adsorption ◽  
Equilibrium And Kinetics ◽  
Equilibrium Data ◽  
Pseudo Second Order ◽  
Adsorption Equilibrium Data ◽  
Kinetics Of

The adsorption of copper in aqueous solutions by steel slag was studied in batch adsorption experiments. The adsorption equilibrium data fitted best with Langmuir and Freundlich equations. The adsorption was preferential type. A comparison of the kinetics models on the apparent adsorption rate showed that the adsorption system was best described by the pseudo-second-order kinetics. The adsorption rate was controlled by both liquid film diffusion and intraparticle dispersion.

Adsorption mechanism of As(V) and As(III) on Fe–Mn binary oxides in synthetic and real water matrices

2016 ◽  
Vol 16 (4) ◽  
pp. 992-1001 ◽  
Author(s):  
Jasmina Nikić ◽  
Jasmina Agbaba ◽  
Malcolm Watson ◽  
Snežana Maletić ◽  
Jelena Molnar Jazić ◽  
...  
Keyword(s):  
Adsorption Mechanism ◽  
Adsorption Equilibrium ◽  
Order Kinetic ◽  
Freundlich Isotherms ◽  
Binary Oxides ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Adsorption Equilibrium Data ◽  
The Eu

A series of Fe–Mn binary oxides with different Fe:Mn ratios (1:1, 3:1, 6:1, 9:1) were synthesized to investigate the optimal Fe:Mn ratio for the removal of As(III) and As(V). Batch experiments were performed to determine the rate of adsorption and equilibrium isotherms. Adsorption kinetics were well described by the pseudo-second-order kinetic model for both As(III) and As(V). The adsorption equilibrium data fitted well to Langmuir and Freundlich isotherms. The maximum As(V) sorption capacity was observed at an Fe:Mn ratio of 6:1 (65.0 mg/g), whereas maximum As(III) uptake was at Fe:Mn ratio 3:1 (46.9 mg/g). Arsenic levels in real water samples were reduced from 37 μg/l to below the EU Water Framework Directive limit (10 μg/L) after treatment with Fe–Mn adsorbents.

scholarly journals MAGNETITE EMBEDDED BIOCHAR AS NANO-SORBENT FOR EFFECTIVE ADSORPTION OF TEXTILE DYE

2021 ◽  
Vol 51 (3) ◽  
pp. 185-192
Author(s):  
M. Seenuvasan ◽  
Carlin Geor Malar ◽  
S.B. Ron Carter ◽  
S. Praveen
Keyword(s):  
High Performance ◽  
Isotherm Models ◽  
Textile Dye ◽  
Neural Structure ◽  
Cassia Auriculata ◽  
Equilibrium Data ◽  
Pseudo Second Order ◽  
Artificial Neural Network Ann ◽  
Adsorption Equilibrium Data ◽  
Best Fit

The nano-sorbent was synthesized by the embedment of magnetite onto the biochar obtained from Cassia auriculata for the effective adsorption of Levafix blue (LB) dye. Different instrumental techniques revealed the properties of biochar and the nano-sorbent. It was very distinct that the nano-sorbent gained highly favorable properties to be an effectual bio-sorbent. The effect of contact time, initial dye concentration and nano-sorbent dosage on the removal of LB dye was examined. Also, out of the kinetics studies models, the best fit and highest R2 values (0.9873) showed that the adsorption followed pseudo-second-order kinetics. Langmuir, Freundlich and Temkin isotherm models were established for the adsorption equilibrium data and the Temkin model showed the best reliability with the experimental results with highest R2 value of 0.9915. The adsorption system was modelled using the Artificial Neural Network (ANN) for biochar and nano-sorbent. The developed well-trained neural structure suggested the high performance of nano-sorbent.    

scholarly journals Adsorption of Phenol from Aqueous Solution Using Lantana camara, Forest Waste: Kinetics, Isotherm, and Thermodynamic Studies

2014 ◽  
Vol 2014 ◽  
pp. 1-16 ◽  
Author(s):  
C. R. Girish ◽  
V. Ramachandra Murty
Keyword(s):  
Lantana Camara ◽  
Isotherm Models ◽  
Order Model ◽  
Experimental Conditions ◽  
Batch Studies ◽  
Forest Waste ◽  
Monolayer Adsorption ◽  
Experimental Parameters ◽  
Equilibrium Data ◽  
Pseudo Second Order

The present work investigates the potential of Lantana camara, a forest waste, as an adsorbent for the phenol reduction in wastewater. Batch studies were conducted with adsorbent treated with HCl and KOH to determine the influence of various experimental parameters such as pH, contact time, adsorbent dosage, and phenol concentration. The experimental conditions were optimized for the removal of phenol from wastewater. Equilibrium isotherms for the adsorption of phenol were analyzed by Freundlich, Langmuir, Temkin, and Dubinin-Radushkevich isotherm models. Thermodynamic parameters like the Gibbs free energy (ΔG°), enthalpy (ΔH°), and entropy (ΔS°) were also determined and they showed that the adsorption process was feasible, spontaneous, and exothermic in the temperature range of 298–328 K. The kinetic data were fitted with pseudo-second-order model. The equilibrium data that followed Langmuir model with the monolayer adsorption capacity was found to be 112.5 mg/g and 91.07 mg/g for adsorbent treated with HCl and KOH, respectively, for the concentration of phenol ranging from 25 to 250 mg/L. This indicates that the Lantana camara was a promising adsorbent for the removal of phenol from aqueous solutions.

scholarly journals Removal of Fluoride and Arsenate from Aqueous Solutions by Aluminum-Modified Guava Seeds

2018 ◽  
Vol 8 (10) ◽  
pp. 1807 ◽  
Author(s):  
Sarai Ramos-Vargas ◽  
Ruth Alfaro-Cuevas-Villanueva ◽  
Rafael Huirache-Acuña ◽  
Raúl Cortés-Martínez
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Equilibrium ◽  
Order Model ◽  
Freundlich Model ◽  
Equilibrium Time ◽  
Fluoride Adsorption ◽  
Batch Type ◽  
Equilibrium Data ◽  
Pseudo Second Order ◽  
Adsorption Equilibrium Data

The contamination of groundwater by arsenic and fluoride is a major problem worldwide, causing diseases in the population that uses these waters for their consumption. Therefore, the removal of these types of pollutants from groundwater is a very important issue. In this work, the removal of arsenate and fluoride from aqueous solutions by using aluminum-modified guava seeds (Al-GSs) was evaluated. Batch-type adsorption experiments were carried out with aqueous solutions of As(V) and F− and Al-GSs. The kinetic and equilibrium parameters of adsorption were determined, as well as the effects of adsorbent dose and pH. The adsorbent was characterized by scanning electron microscopy and infrared spectroscopy in order to determine its morphology and the functional groups present in the material. The results showed that hydroxyl and carboxyl are the main groups involved in the adsorption of As(V) and F−. The fluoride adsorption kinetics indicate that the equilibrium time was reached at 150 min and it can be described by the Lagergren model, while for As(V) the equilibrium time was lower (120 min) and the kinetic data were fitted well to the pseudo-second-order model. The Langmuir-Freundlich model can describe the adsorption equilibrium data in all cases. The fluoride adsorption capacity by Al-GS was 0.3445 mg/g, and for As(V) it was 4 mg/g. It can be established that the removal of arsenates and fluoride in Al-GSs is due to chemisorption on a heterogeneous surface.

scholarly journals Study on efficient removal of clopyralid from water using resorcinol-formaldehyde carbon cryogel

2014 ◽  
Vol 79 (4) ◽  
pp. 481-494 ◽  
Author(s):  
Milan Momcilovic ◽  
Marjan Randjelovic ◽  
Antonije Onjia ◽  
Aleksandra Zarubica ◽  
Biljana Babic ◽  
...  
Keyword(s):  
Amorphous Structure ◽  
High Specific Surface Area ◽  
Isotherm Models ◽  
Experimental Conditions ◽  
Resorcinol Formaldehyde ◽  
Intraparticle Diffusion Model ◽  
Equilibrium Data ◽  
Carbon Cryogel ◽  
Pseudo Second Order ◽  
In The Beginning

Resorcinol-formaldehyde carbon cryogel has been prepared, characterized and used for the removal of commonly used herbicide clopyralid from the aqueous solutions under varying experimental conditions. Carbon has shown a relatively high specific surface area, significant mesoporosity and an amorphous structure. A set of the following isotherm models has been used to interpret the equilibrium data: Langmuir, Freundlich, Temkin, Dubinin-Radushkevich, Jovanovic, Hurkins-Jura, and Helsey model. Several models have fitted well although the calculated values for qmax poorly correlate with the data obtained experimentally. The kinetic models of the pseudo-first and pseudo-second-order, the models of Elovich, Bangham and the intraparticle diffusion model have been used for fitting the kinetic data. The rate of the process is fast in the beginning while adsorption equilibrium is attained not until 24 hours. Adsorption was found to be pH dependent and favored in acidic solutions.

Isotherm, Kinetic and Thermodynamic Studies on Adsorption of Bromocresol Purple, Acid Red 66 and Acid Blue 40 Using Activated Carbon

2021 ◽  
Vol 21 (7) ◽  
pp. 4104-4109
Author(s):  
Jong Jib Lee ◽  
Jong Ki Jeon
Keyword(s):  
Activated Carbon ◽  
Adsorption Process ◽  
Adsorption Equilibrium ◽  
Physical Adsorption ◽  
Isotherm Models ◽  
Bromocresol Purple ◽  
Kinetic And Thermodynamic Parameters ◽  
Equilibrium Data ◽  
Adsorption Equilibrium Data ◽  
Acid Blue

This study was conducted with a batch reaction to equilibrium isotherm, kinetic and thermodynamic parameters on adsorption of bromocresol purple (BCP), acid red 66 (AR 66) and acid blue 40 (AB 40) from aqueous solution by using activated carbon with nanopores. Freundlich and Temkin isotherm models were used to evaluate the suitability of isotherm for adsorption equilibrium data. The adsorption equilibrium was best fitted by Temkin model. The Freundlich separation factor values indicated that adsorption on the nanoporous activated carbon could effectively treat three dyes. The kinetic analysis of the adsorption process confirmed that it was more consistent with the pseudo second order model. The intraparticle diffusion was rate limiting step. The adsorption process of three dyes were endothermic because they were positive enthalpy values. The free energy values of three dyes decreased with increasing temperature, so that the spontaneity becomes higher with temperature increase. The activation energy value of three dyes were confirmed the physical adsorption.

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