The study of adsorption characteristics of electrospun polymer nanofibers for benzenes in water

2011 ◽  
Vol 64 (2) ◽  
pp. 528-533 ◽  
Author(s):  
Jing Sun ◽  
Xue-Jun Kang ◽  
Yu-Qin Ma ◽  
Li-Qin Chen ◽  
Yu Wang ◽  
...  
Keyword(s):  
Standard Free Energy ◽  
Kinetic Studies ◽  
Polymer Nanofibers ◽  
Order Model ◽  
Adsorption Models ◽  
First Order ◽  
Freundlich Isotherms ◽  
Adsorption Performance ◽  
Adsorption Equilibria ◽  
Adsorption Desorption

The adsorption properties of benzene, p-dichlorobenzene and nitrobenzene on polymer nanofibers were studied. Compared with polyacrylonitrile nanofiber, polystyrene (PS) nanofiber presented better adsorption performance. Langmuir and Freundlich adsorption models were used for the mathematical description of adsorption equilibria, and Freundlich isotherms fitted better. Kinetic studies showed that the adsorption of PS nanofiber followed pseudo first-order model. Various thermodynamic parameters such as standard free energy (ΔG), enthalpy (ΔH) and entropy (ΔS) were calculated for predicting the adsorption nature of PS nanofiber for three benzenes, which indicated that the adsorption was spontaneous and a physical process. The regeneration efficiency maintains over 80% after five cycles of adsorption/desorption tests. It showed that PS nanofibers are promising candidates for adsorption and removal of aromatic hydrocarbons from water.

Application of raw and modified Uruguayan clays to phosphate adsorption for water remediation

MRS Advances ◽  
2018 ◽  
Vol 3 (61) ◽  
pp. 3543-3549
Author(s):  
Pablo González ◽  
Andrea C. De Los Santos ◽  
Jorge R. Castiglioni ◽  
María A. De León
Keyword(s):  
Nitrogen Adsorption ◽  
Pillared Clay ◽  
Water Remediation ◽  
Phosphate Adsorption ◽  
X Ray Diffraction ◽  
Order Model ◽  
Freundlich Model ◽  
X Ray ◽  
First Order ◽  
Adsorption Desorption

ABSTRACTA raw clay from Uruguay was modified with aluminium to obtain an aluminium pillared clay (Al-PILC). The solids were characterized by scanning electron microscopy, X-ray diffraction and nitrogen adsorption-desorption isotherms. The Al-PILC retained the typical laminar structure of montmorillonite. The specific surface area and the microporous volume of the Al-PILC, 235 m2 g-1 and 0.096 cm3 g-1, respectively, were much higher than those of the clay. The phosphate adsorption capacity of the Al-PILC was higher than those of the clay. The phosphate adsorption kinetic followed the pseudo-first-order model for both, the clay and the Al-PILC, and the phosphate adsorption isotherm for the Al-PILC fit the Freundlich model.

scholarly journals Reactivity and kinetic studies of benzofuran hydrodeoxygenation over a Ni2P-O/MCM-41 catalyst

2019 ◽  
Vol 44 (4) ◽  
pp. 307-315 ◽  
Author(s):  
Xueya Dai ◽  
Hua Song ◽  
Hualin Song ◽  
Jing Gong ◽  
Feng Li ◽  
...  
Keyword(s):  
Kinetic Studies ◽  
Time Analysis ◽  
Liquid Ratio ◽  
Order Model ◽  
Free Products ◽  
First Order ◽  
Reaction Rate Constants ◽  
Different Temperatures ◽  
Kinetics Of ◽  
Mcm 41

A nickel phosphide hydrodeoxygenation catalyst (Ni2P-O/MCM-41) was prepared using a new synthetic method. The as-prepared catalyst was evaluated in the hydrodeoxygenation of benzofuran, and the effects of reaction temperature, pressure, and the H2/liquid ratio were investigated. A pseudo first-order model was employed to describe the reaction kinetics of benzofuran hydrodeoxygenation over the Ni2P-O/MCM-41 catalyst. The reaction rate constants ( k1– k5) at different temperatures were determined according to this model. At 533 K, the conversion of 2-ethylphenol in to ethylbenzene began to increase dramatically, and the yield of O-free product, ethylcyclohexane, started to increase rapidly. At 573 K, 3.0 MPa, and a H2/liquid ratio of 500 (V/V), the conversion of benzofuran over Ni2P-O/MCM-41 reached 93%, and the combined yield of O-free products was 91%. Contact time analysis indicated that demethylation was not favored over the Ni2P-O/MCM-41 catalyst.

scholarly journals Removal of methylene blue dye from aqueous solution using a superabsorbant hydrogel the polyacrylamide: isotherms and kinetic studies

2019 ◽  
Vol 9 (5) ◽  
pp. 337-346
Author(s):  
Imane Lebkiri ◽  
Brahim Abbou ◽  
Lamya Kadiri ◽  
Abdelkarim Ouass ◽  
Youness Essaadaoui ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Contact Time ◽  
Kinetic Studies ◽  
Organic Dye ◽  
Blue Dye ◽  
Methylene Blue Dye ◽  
Order Model ◽  
First Order ◽  
Kinetics Of ◽  
Maximal Capacity

The present work aims the elimination of an organic dye Methylene Blue (MB) by adsorption on the polyacrylamide (PAAM) hydrogel. Several experiments series were then carried out in order to study the influence on the adsorption capacity of certain parameters such as the mass of the adsorbent, the pH, the contact time, the initial dye concentration and the temperature. The maximal capacity is 1620 mg/g it was obtained at T = 25°C, pH = 6, [BM] = 200 ppm and 0.013g of the adsorbent. The adsorption kinetics of the dye on the support is well described by the first-order model. The adsorption isotherms of the adsorbent/adsorbate systems studied are satisfactorily described by the Langmuir mathematical model. On the other hand, the thermodynamic study revealed that adsorption is spontaneous and endothermic.

FORMULATION AND EVALUATION OF SUSTAIN RELEASE CYCLOBENZAPRINE HYDROCHLORIDE PELLETS

INDIAN DRUGS ◽  
2017 ◽  
Vol 54 (05) ◽  
pp. 19-25
Author(s):  
B. Venkateswara Reddy ◽  
◽  
K. Navaneetha
Keyword(s):  
Kinetic Studies ◽  
Fickian Diffusion ◽  
Stability Studies ◽  
Order Model ◽  
Release Formulation ◽  
Sustained Release Formulation ◽  
First Order ◽  
Sustain Release ◽  
Powder Layering ◽  
Acting Muscle

Cyclobenzaprine Hydrochloride is a centrally acting muscle relaxant which is mostly available in the form of tablets and capsules. The present aim of the study was to develop a sustained release formulation of cyclobenzaprine Hydrochloride pellets using powder layering technique. Nine different formulations of pellets were prepared by using different concentrations of Ethyl Cellulose-50, Hypromellose (HPMC), and PEG 6000 of all formulations, F8 formulation was the optimized formulation. The kinetic studies of F8 formulation was best fitted in the First order model as it had the highest value (R2 = 0.981) and it follows non- fickian diffusion. Among all the formulations F8 gave better drug release 85.7% when compared to innovator, F8 was selected as optimized formulation. The optimized formulation was kept for stability studies for 3 months at 40°C /75% RH and 25°C /60% RH and the results indicated that there was no much variation in their physiochemical characteristics and the formulation was found to be stable.

scholarly journals The adsorption study of Royal Blue Tiafix and Black Tiassolan dyes using bone char as adsorbent

2018 ◽  
Vol 36 (3-4) ◽  
pp. 1178-1198 ◽  
Author(s):  
Rowander A Moura ◽  
Araceli A Seolatto ◽  
Maria E de Oliveira Ferreira ◽  
Fernanda F Freitas
Keyword(s):  
Second Order ◽  
Bone Char ◽  
X Ray Diffraction ◽  
First Order ◽  
Freundlich Isotherms ◽  
Pseudo Second Order ◽  
Dyes Adsorption ◽  
Adsorption Desorption ◽  
Full Factorial ◽  
Kinetics Of

In this study, the potential of bone char for Royal Blue Tiafix and Black Tiassolan dyes adsorption from aqueous solutions was evaluated. The adsorbent was characterized physically and chemically by adsorption/desorption of N2 at 77 K, scanning electron microscopy, X-ray diffraction, and infrared spectroscopy. The equilibrium adsorption results for bone char can be successfully modeled by the Langmuir and Freundlich isotherms. Pseudo-first-order and pseudo-second-order models were used to describe the kinetic data and rate constants were evaluated. Kinetics of each dye was found to follow pseudo-second-order rate kinetic model, with great correlation (higher than 0.99). In order to reduce the number of experiments to achieve better dye removal efficiency, a 2³ full factorial design with three central points and six axial points was applied in the equilibrium experiments. The variables analyzed were agitation, temperature, and pH.

Adsorption of methyl violet from aqueous solution using brown algae Padina sanctae-crucis

2018 ◽  
Vol 43 (6) ◽  
pp. 623-631 ◽  
Author(s):  
Reza Mahini ◽  
Hossein Esmaeili ◽  
Rauf Foroutan
Keyword(s):  
Aqueous Solutions ◽  
Brown Algae ◽  
Contact Time ◽  
Methyl Violet ◽  
Kinetic Studies ◽  
Maximum Adsorption Capacity ◽  
Order Model ◽  
Equilibrium Study ◽  
Freundlich Isotherms ◽  
Pseudo Second Order

Abstract Objective The presence of dyes in the water is toxic and harmful to human body so, it must be removed from the water. In the present study, the removal of methyl violet (MV) from aqueous solutions using brown algae “Padina sanctae-crucis” was investigated. Materials and methods The rate of adsorption was investigated under various parameters such as contact time (5–200), pH (2–11), dye concentration (10–60 mg/L), amount of adsorbent (0.25–5 g/L) and temperature (25–45°C). Results The maximum adsorption was achieved in 10 mg/L, pH=8 and adsorbent dose 2 g/L and 80 min contact time for removal of MV from aqueous solutions. Kinetic studies showed that the pseudo second-order model describes adsorbent kinetic behavior better. Besides, experimental data have been modeled using Langmuir and Freundlich isotherms and the results showed that both models are proper to describe adsorption isotherm behavior. In addition, the equilibrium study shows that the adsorption was physical and favorable. Moreover, a thermodynamic study revealed that the adsorption process is exothermic and spontaneously in nature. Furthermore, Maximum adsorption capacity using adsorbent was 10.02 mg/g. Conclusions It could be concluded that the P. sanctae-crucis biomass is a good adsorbent for removing MV dyes from aqueous solutions.

Removal of Benzene from Aqueous Solution Using Carbon Nanotube Synthesized from Fuel Oil Waste

2014 ◽  
Vol 925 ◽  
pp. 105-109
Author(s):  
Ismail Al-Khateeb ◽  
Ahmed M. Mohammed ◽  
Adawiya J. Haider ◽  
Y. Al-Douri
Keyword(s):  
Aqueous Solution ◽  
Carbon Nanotube ◽  
Power Plants ◽  
Equilibrium Constants ◽  
Fuel Oil ◽  
Order Model ◽  
Adsorption Models ◽  
First Order ◽  
Adsorption Data ◽  
Enthalpy And Entropy

This investigation is dealing with adsorption of benzene compound from aqueous solution using a new carbon nanotube (CNT) synthesized from a fuel oil waste of power plants which identify by FE-SEM and TEM. It was found that a CNT has a very significant adsorption for benzene compared to that of non-activated carbon. The equilibrium adsorption data were analyzed using adsorption models of Langmuir, Freundlich and Temkin. The results showed that the model isotherms are fitting very well with the experimental data. Kinetic study was conducted and the results pointed out that a pseudo-first order model was represented the data. Values of the activation thermodynamic functions were calculated through equilibrium constants at different temperature. All values of Gibbs functions were negative with values of-1.6 and-13.0 kJmol-1 for non-active and CNT respectively, while values of enthalpy and entropy were about-33kJmol-1 and-65JK-1 mol-1 for CNT respectively. These results indicated that the adsorption process was feasible, spontaneous and exothermic.

scholarly journals Brasil nut mesocarp (Bertholletia excels) as a Biomass Source for Activated Carbon Production: Correlation Between Thermal Treatment and Adsorption Performance

2021 ◽  
Vol 12 (4) ◽  
pp. 4584-4596
Keyword(s):  
Activated Carbon ◽  
Maximum Adsorption Capacity ◽  
Brazil Nut ◽  
Order Model ◽  
X Ray ◽  
Adsorption Performance ◽  
Carbon Production ◽  
Pseudo Second Order ◽  
Adsorption Desorption ◽  
Best Fit

The activated carbon investigated in this work was produced from the extractive residues of Brazil nut processing, more specifically from the mesocarp of the Amazonian fruit. The process was performed by muffle pyrolysis, with ZnCl2 impregnation, at 400 and 500 °C. All samples were characterized by X-ray diffractometry, thermogravimetry, CHNS elemental analysis, scanning electron microscopy, and adsorption/desorption of N2. The results were promissory, with 99% removal of methylene blue for the CA25 material, which has a surface area of 1236 m2 g-1, much higher than commercial coal (CAC, 618 m2 g-1). The adsorption kinetics best fit the pseudo-second-order model for all materials. The maximum adsorption capacity obtained was 195.3 mg g-1. Therefore, the extractive residue of Brazil nut has excellent potential for the development of activated carbon, which can be used effectively to mediate environmental contamination in a given aqueous medium.

scholarly journals Studies of adsorption kinetics and regeneration of aniline, phenol, 4-chlorophenol and 4-nitrophenol by activated carbon

2013 ◽  
Vol 19 (2) ◽  
pp. 195-212 ◽  
Author(s):  
S. Suresh ◽  
V.C. Srivastava ◽  
I.M. Mishra
Keyword(s):  
Activated Carbon ◽  
Thermal Desorption ◽  
Kinetic Studies ◽  
Order Model ◽  
Heating Value ◽  
High Heating Value ◽  
Ftir Spectral Analysis ◽  
Pseudo Second Order ◽  
Adsorption Desorption ◽  
Desorption Cycle

The present paper reports kinetic studies of the adsorption of aniline (AN), phenol (P), 4-chlorophenol (CP) and 4-nitrophenol (NP) from aqueous solution onto granular activated carbon (GAC). In FTIR spectral analysis, the transmittance of the peaks gets increased after the loading of AN, P, CP and NP signifying the participation of these functional groups in the adsorption and it seems that the adsorption of AN, P, CP and NP is chemisorptive in nature. The rates of adsorption were found to obey a pseudo-second order model and that the dynamics of AN, P, CP and NP adsorption are controlled by a combination of surface and pore diffusion. The diffusion coefficient were of the order of 10-10 m2 s-1. Thermal desorption at 623 K was found to be more effective than solvent desorption. GAC performed well for at least five adsorption-desorption cycle, with continuous decrease in adsorption efficiency after each thermal desorption. Owing to its relative high heating value, the spent GAC can be used as co-fuel for the production of heat in a boiler or a furnace.

scholarly journals Fabrication of Mesoporous NaZrP Cation-Exchanger for U(VI) Ions Separation from Uranyl Leach Liquors

2019 ◽  
Vol 3 (4) ◽  
pp. 61 ◽  
Author(s):  
Alhindawy ◽  
Elshehy ◽  
El-Khouly ◽  
Abdel-Monem ◽  
Atrees
Keyword(s):  
Kinetic Studies ◽  
Electricity Production ◽  
X Ray Diffraction ◽  
Order Model ◽  
Extraction And Separation ◽  
Inorganic Cation ◽  
Cation Exchangers ◽  
Pseudo Second Order ◽  
Uptake Process ◽  
Adsorption Desorption

As the demand for uranium production-based energy worldwide has been increasing in the last decades to maintain nuclear growth for electricity production, there are great efforts towards developing an easy and inexpensive method for uranium extraction and separation from its ores. For this purpose, mesoporous inorganic cation exchangers provide an efficient separation technology that can help streamline production and lower overall cost. This study describes the development of nano-structured mesoporous sodium zirconium phosphate (NaZrP-CEX) for separation and extraction of uranyl ions from real samples. The fabricated NaZrP-CEX was well characterized by various techniques such as X-ray diffraction (XRD), Fourier Transform Infrared (FTIR), Scanning Electron Microscope (SEM), N2 adsorption/desorption, Dynamic light scattering (DLS) and zeta potential). The kinetics/thermodynamic behaviors of uranyl ion adsorption into NaZrP-CEX from an aqueous solution were minutely studied. The kinetic studies showed that the pseudo-second order model gave a better description for the uptake process. The negative value of ΔG indicate high feasibility and spontaneity of adsorption. Finally, mesoporous NaZrP-CEX can be regenerated using both of HNO3 (0.05 M) or HCl (1 M) up to seven cycles of operation.

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