scholarly journals Elucidation of Adsorption Mechanisms And Mass Transfer Controlling Resistances During Single And Binary Adsorption of Caffeic And Chlorogenic Acids

2021 ◽  
Author(s):  
Eyden S. Hernández-Padilla ◽  
Ana I. Zárate-Guzmán ◽  
Omar González-Ortega ◽  
Erika Padilla-Ortega ◽  
Azael Gómez-Durán ◽  
...  
Keyword(s):  
Experimental Data ◽  
Mass Transfer ◽  
Chlorogenic Acid ◽  
Electrostatic Interactions ◽  
Adsorption Equilibrium ◽  
Order Kinetic ◽  
Chlorogenic Acids ◽  
Binary Adsorption ◽  
Experimental Adsorption ◽  
Adsorption Mechanisms

Abstract In this work, the potential of activated carbon to remove caffeic and chlorogenic acids was investigated. The study focused on evaluating the single and binary adsorption equilibrium, as well as investigating the mass transfer resistances present during the process by applying kinetic and diffusional models for a future scale-up of the process. For both compounds, the single adsorption equilibrium was studied at pH values of 3, 5, and 7. The experimental adsorption isotherms were interpreted using the Langmuir and Freundlich models, obtaining maximum adsorption capacities of 1.33 and 1.62 mmol/g for caffeic and chlorogenic acid, respectively. It was found that the adsorption mechanisms for both compounds was derived from π-π and electrostatic interactions. Also, the binary adsorption equilibrium was performed and the experimental data were interpreted using the extended multicomponent Langmuir model. The results evidenced that the binary adsorption of caffeic acid and chlorogenic acid is antagonistic in nature. The application of the first and second order kinetic models showed that the latter interpreted better the experimental data, obtaining R2 values close to one. Finally, the experimental adsorption rate data were interpreted by a diffusional model, finding the presence of different mass transfer resistances during the adsorption process. For both compounds, intraparticle diffusion mechanisms were meaningful.

Elucidation of adsorption mechanisms and mass transfer controlling resistances during single and binary adsorption of caffeic and chlorogenic acids

2021 ◽  
Author(s):  
Eyden S. Hernández-Padilla ◽  
Ana I. Zárate-Guzmán ◽  
Omar González-Ortega ◽  
Erika Padilla-Ortega ◽  
Azael Gómez-Durán ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Chlorogenic Acids ◽  
Binary Adsorption ◽  
Adsorption Mechanisms

scholarly journals Removal and Adsorption Mechanism of Tetracycline Using Manganese-modified Cotton Straw Biochar in an Aqueous Solution

2021 ◽  
Author(s):  
Xiao Liu ◽  
Shaoyang Shi ◽  
Xuefei Hu ◽  
Tao Sun ◽  
Juanxiang Zhang ◽  
...  
Keyword(s):  
Rural Areas ◽  
Electrostatic Interactions ◽  
Adsorption Process ◽  
Solution Concentration ◽  
Order Kinetic ◽  
Adsorption Effect ◽  
Adsorption Mechanisms ◽  
Aqueous Environments ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Abstract Farming in China’s rural areas leads to antibiotic pollution in waterbodies making it a grave issue. Cotton straw biochar (CSBC) was prepared by oxygen-limited pyrolysis at 400 °C (CSBC400) and 600 °C (CSBC600); and Mn-modified CSBC (MCSBC) was produced by the KMnO4 wrapping method for tetracycline (TC) removal from aqueous solutions. The effects of temperature, initial solution concentration, pH, ion type, and ionic strength on TC adsorption were investigated. The adsorption process of the biochars achieved an equilibrium state after 360 min, and the highest equilibrium adsorption amount (13.254 mg/g) was found for MCSBC. The kinetic adsorption process, which was dominated by chemisorption, was well-described by the pseudo-second-order kinetic model. The adsorption was a non-homogeneous heat absorption process, and the adsorption isotherm data fitting was compatible with the Freundlich model. A better adsorption effect of MCSBC was observed when the pH was < 4. Monovalent cations (Na+, K+, NH4+, and Ca2+) had a facilitative effect on the adsorption process. The adsorption mechanisms of TC by MCSBC included pore diffusion, H bonding, electrostatic interactions, and π–π accumulation. Therefore, MCSBC has a good adsorption capacity for TC and can be used for the treatment of TC-based pollutants in aqueous environments.

scholarly journals Effective adsorption of direct Red 23 by sludge biochar-based adsorbent: adsorption kinetics, thermodynamics and mechanisms study

2021 ◽  
Author(s):  
Ruqing Jiang ◽  
Guangwei Yu ◽  
Pamphile Ndagijimana ◽  
Yu Wang ◽  
Futian You ◽  
...  
Keyword(s):  
Adsorption Kinetics ◽  
Electrostatic Interactions ◽  
Removal Rate ◽  
Order Kinetic ◽  
Solution Ph ◽  
Adsorption Mechanisms ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Solid Adsorbents ◽  
Pseudo Second Order

Abstract Using solid adsorbents, such as biochar, has been a potential practice to remove the pollutants from water bodies to render the water safer for potential usage. A potential application of sludge biochar-based adsorbent (SBA) obtained by pyrolysis with hydrothermal treatment was developed to adsorb Direct Red 23 (DR23) from wastewater. The results showed that the synthesized SBA (0.5 g/L) in the adsorption of DR23 at low concentration (&lt;20 mg/L), the DR23 were totally removed from the aqueous solution. PH had a limited effect on the adsorption, while an increase in temperature was shown to have a large enhancing effect. The adsorption kinetics were the best fit by the pseudo-second-order kinetic model, while the equilibrium data were best fitted by the Langmuir isotherm. A maximum saturation adsorption capacity of SBA of 111.98 mg/g was achieved. SBA could then be regenerated by pyrolysis, and after three cycles, SBA still retained the good adsorption ability of DR23, a removal rate exceeding 97% was achieved. Functional groups, pores, π-π bond, and electrostatic interactions are the key to the adsorption mechanisms. The results proved that SBA would be a promising material in the removal application of dyes in printing and dyeing wastewater.

Photodegradation of some Furocoumarins in Ethanol under UV Irradiation

2016 ◽  
Vol 683 ◽  
pp. 402-405
Author(s):  
Natalya G. Bryantseva ◽  
Olga N. Tchaikovskaya ◽  
Vlada S. Kraiukhina ◽  
Maria Gómez ◽  
Jose Luis Gómez
Keyword(s):  
Experimental Data ◽  
Mass Transfer ◽  
Kinetic Model ◽  
Kinetic Parameter ◽  
Bulk Solution ◽  
Order Kinetic ◽  
First Order ◽  
Operational Variables ◽  
Pseudo First Order ◽  
Good Agreement

Photodegradation of 5-Methoxypsoralen (5-MOP), 4', 5'-dimethyl-3,4-cyclogeksilpsoralen (KC5) and 4'-methyl-3,4 cycloheptylpsoralen (KC4) has been carried out in an XeBr exilamps, both in the presence of H2O2, and a kinetic model, which explains the dependence of the pseudo-first order kinetic parameter on the substrate concentration and other operational variables, has been developed. In the development of the model, mass transfer of 5-MOP, KC5 and KC4from the bulk solution to the wall of the vessel was assumed as the step determining the rate of the photodegradation process, which successfully explains some singularities observed in the experimental results.By fitting the experimental data to the model, a detailed study of the influence of all operational variables on the pseudo-first order kinetic parameter has been done, in good agreement with the model hypotheses.

Kinetic and thermodynamic study of the adsorption of calcium onto sugar beet pulp

2016 ◽  
pp. 565-570
Author(s):  
Huang Qin ◽  
Zhu Si-ming ◽  
Zeng Di ◽  
Yu Shu-juan
Keyword(s):  
Sugar Beet ◽  
Adsorption Equilibrium ◽  
Ph Value ◽  
Hard Water ◽  
Sugar Beet Pulp ◽  
Order Kinetic ◽  
Factors Affecting ◽  
Isotherm Equation ◽  
Equilibrium Data ◽  
Beet Pulp

Sugar beet pulp (SBP) was used as low value adsorbent for the removal of calcium from hard water. Batch experiments were conducted to determine the factors affecting adsorption of the process such as pH value and Ca concentration. The adsorption equilibrium of Ca2+ by the SBP is reached after 100min and a pseudo second-order kinetic model can describe the adsorption process. The initial concentrations of Ca varied from 927 to 1127mgCa2+/L. A dose of 30g/L sugar beet pulp was sufficient for the optimum removal of calcium. The overall uptake of Ca ions by sugar beet pulp has its maximum at pH=8. The adsorption equilibrium data fitted well with the Langmuir adsorption isotherm equation.

Comparison of the fixation of several metal ions onto a low-cost biopolymer

2002 ◽  
Vol 2 (5-6) ◽  
pp. 217-224 ◽  
Author(s):  
Z. Reddad ◽  
C. Gérente ◽  
Y. Andrès ◽  
P. Le Cloirec
Keyword(s):  
Aqueous Solutions ◽  
Metal Ions ◽  
Low Cost ◽  
Operating Conditions ◽  
Order Kinetic ◽  
Adsorption Mechanisms ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Beet Pulp ◽  
Removal Of Metal Ions

In the present work, sugar beet pulp, a common waste from the sugar refining industry, was studied in the removal of metal ions from aqueous solutions. The ability of this cheap biopolymer to sorb several metals namely Pb2+, Cu2+, Zn2+, Cd2+ and Ni2+ in aqueous solutions was investigated. The metal fixation capacities of the sorbent were determined according to operating conditions and the fixation mechanisms were identified. The biopolymer has shown high elimination rates and interesting metal fixation capacities. A pseudo-second-order kinetic model was tested to investigate the adsorption mechanisms. The kinetic parameters of the model were calculated and discussed. For 8 × 10-4 M initial metal concentration, the initial sorption rates (v0) ranged from 0.063 mmol.g-1.min-1 for Pb2+ to 0.275 mmol.g-1.min-1 for Ni2+ ions, with the order: Ni2+ &gt; Cd2+ &gt; Zn2+ &gt; Cu2+ &gt; Pb2+. The equilibrium data fitted well with the Langmuir model and showed the following affinity order of the material: Pb2+ &gt; Cu2+ &gt; Zn2+ &gt; Cd2+ &gt; Ni2+. Then, the kinetic and equilibrium parameters calculated qm and v0 were tentatively correlated to the properties of the metals. Finally, equilibrium experiments in multimetallic systems were performed to study the competition of the fixation of Pb2+, Zn2+ and Ni2+ cations. In all cases, the metal fixation onto the biopolymer was found to be favourable in multicomponent systems. Based on these results, it is demonstrated that this biosorbent represents a low-cost solution for the treatment of metal-polluted wastewaters.

A novel approach in numerical simulation of contaminant removal by air sparging

2007 ◽  
Vol 7 (3) ◽  
pp. 163-170
Author(s):  
N. Jacimovic ◽  
T. Hosoda ◽  
M. Ivetic ◽  
K. Kishida
Keyword(s):  
Mass Transfer ◽  
Deterministic Model ◽  
Water Phase ◽  
Air Sparging ◽  
Order Kinetic ◽  
Contaminant Removal ◽  
Water Compartments ◽  
Novel Approach ◽  
Adopted Model ◽  
Air Channels

The paper presents a mechanistic/deterministic model for simulation of mass removal during air sparging. From the point of numerical modeling, there are two issues considering air sparging: modeling of air flow and distribution and modeling of mass transport and transfer. Several processes, which are commonly neglected, such as air channeling and pollutant advection by the water phase, are taken into account. The numerical model presented in this paper considers all relevant for mass transfer during the air sparging. Model includes hydrodynamics of air and water phase; calculated air volume content is divided into a number of air channels surrounded by the water phase, which is divided into two compartments. First compartment is immobile and it is in contact with air phase, while the second compartment is mobile. This “mobile-immobile” formulation is a common approach for description of solute transport by groundwater. Mass transfer between two water compartments is modeled as a first order kinetic, where the mass transfer coefficient, representing diffusion and advection in the water phase towards the air channels, is parameter needed to be calibrated. Sorption for both water compartments is considered. The adopted model of contaminant evaporation at the air-water interface is verified by comparison with experimental results available from published sources. Model is used for simulation of two-dimensional air sparging laboratory experiment. Good overall agreement is observed. It is showed that the efficiency of air sparging can be influenced by natural groundwater flow.

Simultaneous heat and mass transfer during evaporation from a film of liquid into the turbulent gas

1982 ◽  
Vol 47 (3) ◽  
pp. 766-775 ◽  
Author(s):  
Václav Kolář ◽  
Jan Červenka
Keyword(s):  
Experimental Data ◽  
Mass Transfer ◽  
Liquid Film ◽  
Heat And Mass Transfer ◽  
Driving Forces ◽  
Proper Definition ◽  
Definition Of ◽  
Simultaneous Heat ◽  
Theory And Experiment

The paper presents results obtained by processing a series of published experimental data on heat and mass transfer during evaporation of pure liquids from the free board of a liquid film into the turbulent gas phone. The data has been processed on the basis of the earlier theory of mechanism of heat and mass transfer. In spite of the fact that this process exhibits a strong Stefan's flow, the results indicate that with a proper definition of the driving forces the agreement between theory and experiment is very good.

Mass Transfer in Liquid in an Apparatus with Mobile Packing. Application of a Dispersion Model

1993 ◽  
Vol 58 (5) ◽  
pp. 1078-1086
Author(s):  
Zdeněk Palatý
Keyword(s):  
Experimental Data ◽  
Mass Transfer ◽  
Empirical Equation ◽  
Dispersion Model ◽  
Transfer Coefficients ◽  
Mass Transfer Coefficients

The paper deals with the mass transfer in a liquid on a plate with mobile packing. A procedure has been suggested which enables estimation of the mass transfer coefficients from experimental data considering the dispersion flow of the liquid. The results obtained from the desorption of CO2 from water are presented graphically and in the form of empirical equation.

A Method for Estimating Mass Transfer Coefficients in a Packed Column Using Reactive Absorption Data

2005 ◽  
Vol 70 (3) ◽  
pp. 383-402
Author(s):  
Valery A. Danilov ◽  
Il Moon
Keyword(s):  
Experimental Data ◽  
Mass Transfer ◽  
Optimization Technique ◽  
Packed Column ◽  
Effective Area ◽  
Transfer Coefficients ◽  
Mass Transfer Coefficients ◽  
Model Calculations ◽  
Unit Model ◽  
Reactive Absorption

This paper is devoted to the development of a new method for estimating mass transfer coefficients and effective area in packed columns in the case of reactive absorption. The method is based on a plug-flow model of reactive absorption of carbon dioxide with sodium hydroxide solution. The parameter estimation problem is solved using an optimization technique. Some mass transfer parameters are found to be correlated. Global sensitivity analysis by Sobol's technique showed that the unit model with the defined objective function is sensitive to the estimated parameter. Case studies of reactive absorption with different packings illustrate application of the proposed method for estimating mass transfer coefficients and effective area from column operation data. The model calculations are compared with experimental data obtained by other authors. The concentration profiles calculated by the unit model with the estimated parameters are shown to match well with experimental profiles from literature. A good agreement between estimated values and experimental data from literature confirms the applicability of this method.

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