Absorption Equilibrium and Thermodynamics of Fenugreek Yellow Pigment on Macroporous Resins

2011 ◽  
Vol 233-235 ◽  
pp. 91-94
Author(s):  
Feng Han ◽  
Wen Hong Li ◽  
Xuan Tang ◽  
Dong Li
Keyword(s):  
Free Energy ◽  
Thermodynamic Parameters ◽  
Gibbs Free Energy ◽  
Adsorption Equilibrium ◽  
Yellow Pigment ◽  
Adsorption Models ◽  
Freundlich Model ◽  
Langmuir Adsorption ◽  
Macroporous Resins ◽  
Equilibrium Data

The adsorption equilibrium and thermodynamics of pigment extracted from Fenugreek after degumming on macroporous resins was investigated under differentinitial concentrations. The suitability of the Freundlich and Langmuir adsorption models to the equilibrium data was investigated. The model fitness was determined by R2 . Thermodynamic parameters were calculated by the Van’t Hof equation.The results showed that Freundlich model gave a better fit of adsorption isotherms than Langmuir models. The positive value of enthalpy(∆H) indicated that the adsorption was endothermic, the negative value of Gibbs free energy (∆G) showed the spontaneous and favoured nature of adsorption, and the entropy(∆S) was positive.The resins LS-46 showed an effective adsorbtion for Fenugreek yellow pigment.

scholarly journals Study on Adsorption of Cu and Ba from Aqueous Solutions Using Nanoparticles of Origanum (OR) and Lavandula (LV)

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Ghadah M. Al-Senani ◽  
Foziah F. Al-Fawzan
Keyword(s):  
Heavy Metals ◽  
Particle Size ◽  
Free Energy ◽  
Aqueous Solutions ◽  
Thermodynamic Parameters ◽  
Solution Ph ◽  
Environment Friendly ◽  
Removal Of Heavy Metals ◽  
Equilibrium Data ◽  
Langmuir And Freundlich Models

Wild herbs (Origanum (OR) and Lavandula (LV)) were used as environment-friendly adsorbents in this study. The adsorbents were used for adsorption of Cu and Ba from water. The adsorption of heavy metals onto OR and LV was dependent on particle size, dose, and solution pH. The diameter of adsorbent particles was less than 282.8 nm. The adsorption follows second-order kinetics. Langmuir and Freundlich models have been applied to describe the equilibrium data, and the thermodynamic parameters, the Gibbs free energy, ∆G°, enthalpy, ∆H°, and entropy, ∆S°, have been determined. The positive value of ∆H° suggests that the adsorption of heavy metals by the wild herbs is endothermic. The negative values of ∆G° at all the studied temperatures indicate that the adsorption is a spontaneous process. It can be concluded that OR and LV are promising adsorbents for the removal of heavy metals from aqueous solutions over a range of concentrations.

Thermodynamics of Organic Dyes Adsorption onto Thermal Modified Rectorite

2012 ◽  
Vol 463-464 ◽  
pp. 194-197
Author(s):  
Jing Yan Song ◽  
Ling Rong He
Keyword(s):  
Free Energy ◽  
Gibbs Free Energy ◽  
Organic Dyes ◽  
X Ray Diffraction ◽  
Adsorption Interaction ◽  
Equilibrium Data ◽  
Different Temperatures ◽  
Hoff Equation ◽  
Dyes Adsorption ◽  
Langmuir And Freundlich Equations

Adsorption behavior of Rhodamine B (RhB) onto thermal modified rectorite (TM-R) has been thermodynamically investigated. The thermal modified rectorite prepared at different temperatures was characterized by X-ray diffraction (XRD) and Brunauer-Emmett-Teller (BET). The analysis of the isotherm equilibrium data using the Langmuir and Freundlich equations by linear methods showed that the data fitted better with Freundlich model than the Langmuir model. Thermodynamic parameters were calculated based on Van’t Hoff equation. The average change of standard adsorption heat of RhB was 88.96 kJ/mol. The adsorption Gibbs free energy changes are in the range of -26.88～-34.52 kJ/mol, The negative of adsorption Gibbs free energy changes in all cases are indicative of the spontaneous nature of the adsorption interaction, and the values of adsorption entropy changes are positive.

scholarly journals Adsorption of Phenol from Aqueous Solution using Paper Waste

2019 ◽  
Vol 20 (1) ◽  
pp. 23-29
Author(s):  
Huda Adil Sabbar
Keyword(s):  
Contact Time ◽  
Phenol Concentration ◽  
Phenol Removal ◽  
Adsorption Models ◽  
Freundlich Model ◽  
Paper Waste ◽  
Equilibrium Data ◽  
Initial Phenol Concentration ◽  
Recyclable Resources ◽  
Adsorbent Dose

The exploitation of obsolete recyclable resources including paper waste has the advantages of saving resources and environment protection. This study has been conducted to study utilizing paper waste to adsorb phenol which is one of the harmful organic compound byproducts deposited in the environment. The influence of different agitation methods, pH of the solution (3-11), initial phenol concentration (30-120ppm), adsorbent dose (0.5-2.5 g) and contact time (30-150 min) were studied. The highest phenol removal efficiency obtained was 86% with an adsorption capacity of 5.1 mg /g at optimization conditions (pH of 9, initial phenol concentration of 30 mg/L, an adsorbent dose of 2 g and contact time of 120min and at room temperature). The well-known Langmuir and Freundlich adsorption models were studied. The results show that the equilibrium data fitted to the Freundlich model with R2=0.9897 within the concentration range studied. The main objective of this study is finding the best mixing and conditions for phenol removal by adsorption via paper waste.

scholarly journals CMC Determination and Thermodynamic Micellisation Of NPE Surfactant In Aqueous And CH3OH – H2O Solvents

2013 ◽  
Vol 10 (3) ◽  
pp. 1050-1056
Author(s):  
Baghdad Science Journal
Keyword(s):  
Surface Tension ◽  
Free Energy ◽  
Critical Micelle Concentration ◽  
Binary Mixture ◽  
Thermodynamic Parameters ◽  
Gibbs Free Energy ◽  
Standard Gibbs Free Energy ◽  
Good Linearity ◽  
Methanol Solutions ◽  
Compensation Behavior

The critical micelle concentration (CMC) of nonylphenolethoxylate (NPE) surfactant has been determined by measuring the surface tension as a function of the molar concentration of the surfactant in aqueous and binary mixture of water + methanol solutions at a temperature range from 20?C to 35?C. The interfacial parameters ?max, Amin, ?cmc and ?G?ads were calculated. The results indicate that the CMC increases as the temperature increases and that the addition of methanol the CMC decreases. The thermodynamic parameters such as standard Gibbs free energy (?G?), enthalpy (?H?), and entropy (?S?) of micellization were estimated using the change of CMC with temperature. The enthalpy – entropy compensation behavior of the surfactant was evaluated and a good linearity in the compensation plot has been observed.

Thermodynamic Parameters of Nonisothermal Degradation of A New Family of Organometallic Dendrimer with Isoconversional Methods

2021 ◽  
Author(s):  
Ahmad Ali Joraid ◽  
Rawda Mohammad Okasha ◽  
Mahdi A. Al-Maghrabi ◽  
Tarek H. Afifi ◽  
Christian Agatemor ◽  
...  
Keyword(s):  
Activation Energy ◽  
Free Energy ◽  
Thermodynamic Parameters ◽  
Gibbs Free Energy ◽  
Effective Activation Energy ◽  
Isoconversional Methods ◽  
Degradation Process ◽  
Effective Activation ◽  
Exponential Factor ◽  
New Family

Abstract The objective of this work is to obtain the thermodynamic parameters, namely, the changes of enthalpy, Gibbs free energy, and the entropy of two degradation steps observed in three of a new family of organometallic dendrimers. The isoconversional Flynn-Wall-Ozawa (FWO) model was employed to calculate the effective activation energy and pre-exponential factor. The changes of enthalpy and the entropy was consistent with the activation energy, whereas the change of Gibbs free energy remains positive during the entire degradation process, implying that the degradation is non-spontaneous and thus requires external heat supply.

scholarly journals Influence of Cu Content on Structure and Magnetic Properties in Fe86-xCuxB14 Alloys

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1451 ◽  
Author(s):  
Tymon Warski ◽  
Patryk Wlodarczyk ◽  
Marcin Polak ◽  
Przemyslaw Zackiewicz ◽  
Adrian Radon ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Free Energy ◽  
Thermodynamic Parameters ◽  
Gibbs Free Energy ◽  
Amorphous Phase ◽  
Phase Formation ◽  
Crystallization Kinetics ◽  
Core Loss ◽  
Cu Content ◽  
Amorphous Phase Formation

Influence of Cu content on thermodynamic parameters (configurational entropy, Gibbs free energy of mixing, Gibbs free energy of amorphous phase formation), crystallization kinetics, structure and magnetic properties of Fe86-xCuxB14 (x = 0, 0.4, 0.55, 0.7, 1) alloys is investigated. The chemical composition has been optimized using a thermodynamic approach to obtain a minimum of Gibbs free energy of amorphous phase formation (minimum at 0.55 at.% of Cu). By using differential scanning calorimetry method the crystallization kinetics of amorphous melt-spun ribbons was analyzed. It was found that the average activation energy of α-Fe phase crystallization is in the range from 201.8 to 228.74 kJ/mol for studied samples. In order to obtain the lowest power core loss values, the isothermal annealing process was optimized in the temperature range from 260 °C to 400 °C. Materials annealed at optimal temperature had power core losses at 1 T/50 Hz—0.13–0.25 W/kg, magnetic saturation—1.47–1.6 T and coercivity—9.71–13.1 A/m. These samples were characterized by the amorphous structure with small amount of α-Fe nanocrystallites. The studies of complex permeability allowed to determine a minimum of both permeability values at 0.55 at.% of Cu. At the end of this work a correlation between thermodynamic parameters and kinetics, structure and magnetic properties were described.

Thermodynamic Parameters Analysis of MgS Superfine Inclusion in Grain Boundary

2012 ◽  
Vol 217-219 ◽  
pp. 174-178
Author(s):  
Shao Bo Zheng ◽  
Chun Feng Wu ◽  
Cun Bo Yang ◽  
Yue Gong ◽  
Hui Gai Li
Keyword(s):  
Free Energy ◽  
Grain Boundary ◽  
Thermodynamic Parameters ◽  
Gibbs Free Energy ◽  
Free Volume ◽  
Activity Coefficients ◽  
Plate Steel ◽  
Miedema Model ◽  
Free Volume Theory ◽  
Parameters Analysis

Activity coefficients and concentrations of dissolved magnesium and sulfur in grain boundary are two essential parts for the calculation of the Gibbs free energy of MgS superfine inclusion in grain boundary. Activity coefficients of dissolved magnesium and sulfur in grain boundary are gained first by the use of Miedema Model and Free Volume Theory. Concentrations of dissolved magnesium and sulfur in grain boundary of Fe-matrix are gained by Mclean’s equation. At last the Gibbs free energy of MgS in grain boundary is -14.048KJ/mol in E-class ship plate steel at T=1363K. By comparing the values of the Gibbs free energy of MgS in grain boundary and that in grain interior, a conclusion can be come to that MgS superfine inclusions may form in grain boundary instead of in grain interior.

scholarly journals Sewage Water Deironing with Carbon Sorbents

2012 ◽  
pp. 90-98
Author(s):  
Keyword(s):  
Free Energy ◽  
Thermodynamic Parameters ◽  
Gibbs Free Energy ◽  
Sewage Water ◽  
Dynamic Conditions ◽  
Electroplating Wastewater ◽  
Carbon Sorbents ◽  
Entropy Changes ◽  
Enthalpy And Entropy Changes ◽  
Enthalpy And Entropy

The possibility of extraction of iron cations Fe2+ from the wash plant electroplating wastewater by carbon sorbents IPI-T synthesized in ISTU has been stated in this work. In this paper we studied the regularities of sorption in static and dynamic conditions, the numerical values defined limiting sorption of iron cations Fe2+ in the interval of temperatures 293-313 K. Such thermodynamic parameters of sorption as Gibbs free energy and enthalpy and entropy changes have been calculated.

scholarly journals Thermodynamic Analysis of Moisture Adsorption of Taraxacum Officinale’ Powder

2020 ◽  
Vol 12 (2) ◽  
pp. 58-66
Author(s):  
Haytem Moussaoui ◽  
Zakaria Tagnamas ◽  
Younes Bahammou ◽  
Mounir Kouhila ◽  
Ali Idlimam ◽  
...  
Keyword(s):  
Free Energy ◽  
Thermodynamic Properties ◽  
Gibbs Free Energy ◽  
Taraxacum Officinale ◽  
Sorption Process ◽  
Gibbs Free Energy Change ◽  
Moisture Adsorption ◽  
Adsorption Phenomenon ◽  
Equilibrium Data ◽  
Physical Principles

This work aims to model the adsorption isotherms and study the essential thermodynamic properties of Taraxacum Officinale’ powder during the moisture adsorption phenomenon at three temperatures 30, 40, and 50°C. The results have been determined by the application of the thermodynamics physical principles to the equilibrium data, which are experimentally measured. The estimated values of the isokinetic and harmonic temperatures and the Gibbs free energy change revealed that the sorption process is non-spontaneous and enthalpy driven.

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