scholarly journals Adsorptive Separation Studies ofβ-Carotene from Methyl Ester Using Mesoporous Carbon Coated Monolith

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
M. Muhammad ◽  
Moonis Ali Khan ◽  
T. S. Y. Choong
Keyword(s):  
Methyl Ester ◽  
Adsorption Capacity ◽  
Contact Time ◽  
Mesoporous Carbon ◽  
Adsorption Process ◽  
Physical Adsorption ◽  
Order Model ◽  
Kinetics And Thermodynamics ◽  
Carbon Coated ◽  
Pseudo Second Order

Adsorption ofβ-carotene on mesoporous carbon coated monolith (MCCM) from methyl ester as a solvent was investigated. Kinetics and thermodynamics parameters have been evaluated. Maximumβ-carotene adsorption capacity was 22.37 mg/g at 50 °C. Process followed Langmuir isotherm. The adsorption was endothermic and spontaneous. Contact time studies showed increase in adsorption capacity with increase inβ-carotene initial concentration and temperature. Pseudo-second-order model was applicable to the experimental data. The value of activation energy confirmed physical adsorption process.

Removal of sunset yellow FCF from aqueous solution using polyethyleneimine-modified MWCNTs

2015 ◽  
Vol 73 (6) ◽  
pp. 1269-1278 ◽  
Author(s):  
Hejun Gao ◽  
Luanluan Zhang ◽  
Yunwen Liao
Keyword(s):  
Adsorption Capacity ◽  
Contact Time ◽  
Adsorption Mechanism ◽  
Adsorption Process ◽  
Langmuir Model ◽  
Order Model ◽  
Sunset Yellow ◽  
Multi Wall Carbon Nanotubes ◽  
Initial Ph ◽  
Pseudo Second Order

A novel adsorbent consisting of polyethyleneimine-modified multi-wall carbon nanotubes (PEI-MWCNTs) was synthesized by grafting PEI on the carboxyl MWCNTs. The surface properties of the PEI-MWCNTs were measured by scanning electron microscopy, thermogravimetric analysis, Fourier transform infrared, and zeta potential. The adsorption behavior of the PEI-MWCNTs was investigated using sunset yellow FCF as adsorbate. The effects of dosage of adsorbent, the initial pH of solution, contact time and temperature on the adsorption capacity were studied. Then, the kinetics and thermodynamics of the adsorption process were further investigated. Experimental results showed that the adsorption kinetics fitted a pseudo-second-order model and the adsorption isotherms agreed well with the Langmuir model. The adsorption process occurred very fast and the adsorption capacity of PEI-MWCNTs was much higher than that of many of the previously reported adsorbents. Additionally, the plausible adsorption mechanism was discussed.

scholarly journals Equilibrium and Kinetic Study of Lead and Copper Ion Adsorption on Chitosan-Grafted-Polyacrylic Acid Synthesized by Surface Initiated Atomic Transfer Polymerization

Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2218 ◽  
Author(s):  
Carlos Grande-Tovar ◽  
William Vallejo ◽  
Fabio Zuluaga
Keyword(s):  
Adsorption Capacity ◽  
Polyacrylic Acid ◽  
Adsorption Process ◽  
Kinetic Constant ◽  
Copper Ion ◽  
Toxic Metal ◽  
Maximum Adsorption Capacity ◽  
Order Model ◽  
Equilibrium Studies ◽  
Pseudo Second Order

In this work, we synthesized chitosan grafted-polyacrylic acid (CS-g-PA) through surface-initiated atom transfer radical polymerization (SI-ATRP). We also studied the adsorption process of copper and lead ions onto the CS-g-PA surface. Adsorption equilibrium studies indicated that pH 4.0 was the best pH for the adsorption process and the maximum adsorption capacity over CS-g-PA for Pb2+ ions was 98 mg·g−1 and for Cu2+ it was 164 mg·g−1, while for chitosan alone (CS), the Pb2+ adsorption capacity was only 14.8 mg·g−1 and for Cu2+ it was 140 mg·g−1. Furthermore, the adsorption studies indicated that Langmuir model describes all the experimental data and besides, pseudo-second-order model was suitable to describe kinetic results for the adsorption process, demonstrating a larger kinetic constant of the process was larger for Pb2+ than Cu2+. Compared to other adsorbents reported, CS-g-PA had comparable or even superior adsorbent capacity and besides, all these results suggest that the new CS-g-PA polymers had potential as an adsorbent for hazardous and toxic metal ions produced by different industries.

scholarly journals Recovery of phosphate from aqueous solution by magnetically recycled modified polishing powder composites

2019 ◽  
Vol 80 (7) ◽  
pp. 1357-1366
Author(s):  
Jianming Liu ◽  
Runying Bai ◽  
Junfeng Hao ◽  
Bowen Song ◽  
Yu Zhang ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Ligand Exchange ◽  
Adsorption Process ◽  
High Adsorption ◽  
Order Model ◽  
Powder Composites ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Ph Level ◽  
Adsorption Desorption

Abstract This study investigated a magnetically recycled modified polishing powder (CMIO@PP) as an adsorbent of phosphate; the CMIO@PP was synthesized by combining the modified La/Ce-containing waste polishing powder with CaO2-modified Fe3O4 (CMIO). Results indicate that the CMIO@PP nanocomposite presents a crystal structure comprising La (OH)3, Ce (OH)3, and Fe3O4, and that CMIO is uniformly dispersed in the modified polishing powder. The CMIO@PP (1:3) is a suitable choice considering its magnetism and adsorption capacity. The magnetic adsorbent exhibits a high adsorption capacity of 53.72 mg/g, a short equilibrium time of 60 min, and superior selectivity for phosphate. Moreover, the adsorbent strongly depends on the pH during the adsorption process and maintains a large adsorption capacity when the pH level is between 2 and 6. The adsorption of phosphate by the CMIO@PP (1:3) accords with the Langmuir isotherm model, and the adsorption process follows the pseudo-second order model. Meanwhile, adsorption–desorption experiments show that the adsorbent could be recycled a few times and that a high removal efficiency of phosphate from civil wastewater was achieved. Finally, mechanisms show that the adsorption of phosphate by the CMIO@PP (1:3) is mainly caused by electrostatic attraction and ligand exchange.

scholarly journals Removal of Fluoride Ion from Water Using locally Produced Adsorbent

2019 ◽  
Vol 4 (12) ◽  
pp. 78-85
Author(s):  
Aboiyaa A. Ekine ◽  
Patience N. Ikenyiri ◽  
O. Hezekiah-Braye
Keyword(s):  
Particle Size ◽  
Adsorption Capacity ◽  
Contact Time ◽  
Adsorption Process ◽  
Intraparticle Diffusion ◽  
Fluoride Ion ◽  
First Order ◽  
Egg Shells ◽  
Pseudo Second Order ◽  
Pseudo First Order

This Research investigated the adsorption capacity of locally prepared adsorbents from Egg shells for the removal of fluoride ion in well water. It evaluated the performance of these adsorbents calcinated at 3000C and modified with 1.0M HNO3 (trioxonitrate (v)) acid. Batch adsorber was used to allow for interaction between adsorbent (grounded Egg shells) with water containing fluoride ion. The batch experiment was performed with particle size of 2.12 contact time (60, 120, 180, 240, 300min), mass dosage (5g, 10g, 15g, 20g) and temperature (250C, 300C, 400C, 500C). The modified adsorbent was characterized to determine the physiochemical properties of grounded Egg shells (GE). Also the chemical composition of the modified adsorbent was analyzed to determine the percentage of calcium element required for the uptake of the fluoride ions in water for calcium as 39.68% for grounded Egg shells (GE). Percentage adsorption increased with increase in contact time, mass dosage and temperature for the adsorbent. The adsorption capacity was also determined which also increased with increase in contact time, temperature but decreased with increase in mass dosage at constant time of 60minutes. The pseudo first-order, pseudo second order and intraparticle diffusion kinetic models were fitted into the experimental results. The results obtained indicated that the pseudo first order and intraparticle diffusion models for the grounded Egg shells (GE) reasonably described the adsorption process very well whereas the pseudo second order model was not suitable for a calcinations temperature of 3000C and particle size of 2.12m. The adsorption isotherms were obtained from equilibrium experiment Performed at temperature of 25, 35, 45 and 550C. The result showed that Langmuir and Freundlich isotherm fitted perfectly the experimental data. However, the negative values of Gibb’s free energy indicated that adsorption was favourable and the positive enthalpy change H0 revealed that adsorption process was endothermic while the positive value of the entropy change signified increased randomness with adsorption.

scholarly journals Development of Pectin-Based Aerogels with Several Excellent Properties for the Adsorption of Pb2+

Foods ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3127
Author(s):  
Risi Wang ◽  
Ya Li ◽  
Xixiang Shuai ◽  
Jun Chen ◽  
Ruihong Liang ◽  
...  
Keyword(s):  
Mechanical Strength ◽  
Adsorption Capacity ◽  
Functional Groups ◽  
Adsorption Process ◽  
Diglycidyl Ether ◽  
Order Model ◽  
High Mechanical Strength ◽  
Adsorption Data ◽  
Pseudo Second Order ◽  
Large Maximum

Traditional aerogels lack specific functional groups for the adsorption of Pb2+, which results in a low adsorption capacity and limits the application scope. Novel porous pectin-based aerogels (PPEAs) were prepared by incorporating polyethylenimine (PEI) using ethylene glycol diglycidyl ether (EGDE) as a cross-linker for the removal of Pb2+ from water. The cross-linking mechanism, morphology, mechanical strength, thermal stability, adsorption properties, and mechanism of the aerogels were investigated. The aerogels possessed several desirable features, such as a large maximum Pb2+ adsorption capacity (373.7 mg/g, tested at pH 5.0), ultralight (as low as 63.4 mg/cm3), high mechanical strength (stress above 0.24 MPa at 50% strain), and easy recyclability. Meanwhile, the equilibrium adsorption data was well described by the Langmuir–Freundlich (Sips) model and the kinetic adsorption process was well fitted using the pseudo-second-order model. The donor groups, such as -NH2, and oxygen-containing functional groups were responsible for the Pb2+ adsorption, which was confirmed by the FTIR and XPS analysis. The excellent characteristics mean that PPEAs are highly effective adsorbents in the remediation of lead-containing wastewater.

scholarly journals Corn stalk as starting material to prepare a novel adsorbent via SET-LRP and its adsorption performance for Pb(II) and Cu(II)

2020 ◽  
Vol 7 (3) ◽  
pp. 191811
Author(s):  
Yazhen Wang ◽  
Shuang Li ◽  
Liqun Ma ◽  
Shaobo Dong ◽  
Li Liu
Keyword(s):  
Adsorption Capacity ◽  
Potassium Hydroxide ◽  
Adsorption Process ◽  
Hydroxylamine Hydrochloride ◽  
Freundlich Isotherm ◽  
Maximum Adsorption Capacity ◽  
Corn Stalk ◽  
Order Model ◽  
Adsorption Performance ◽  
Pseudo Second Order

Corn stalk was used as the initial material to prepare a corn stalk matrix-g-polyacrylonitrile-based adsorbent. At first, the corn stalk was treated with potassium hydroxide and nitric acid to obtain the corn stalk-based cellulose (CS), and then the CS was modified by 2-bromoisobutyrylbromide (2-BiBBr) to prepare a macroinitiator. After that, polyacrylonitrile (PAN) was grafted onto the macroinitiator by single-electron transfer living radical polymerization (SET-LRP). A novel adsorbent AO CS-g-PAN was, therefore, obtained by introducing amidoxime groups onto the CS-g-PAN with hydroxylamine hydrochloride (NH 2 OH · HCl). FTIR, SEM and XPS were applied to characterize the structure of AO CS-g-PAN. The adsorbent was then employed to remove Pb(II) and Cu(II), and it exhibited a predominant adsorption performance on Pb(II) and Cu(II). The effect of parameters, such as temperature, adsorption time, pH and the initial concentration of metal ions on adsorption capacity, were examined in detail during its application. Results suggest that the maximum adsorption capacity of Pb(II) and Cu(II) was 231.84 mg g –1 and 94.72 mg g −1 , and the corresponding removal efficiency was 72.03% and 63%, respectively. The pseudo-second order model was more suitable to depict the adsorption process. And the adsorption isotherm of Cu(II) accorded with the Langmuir model, while the Pb(II) conformed better to the Freundlich isotherm model.

Adsorption Characters of Mn2+ onto Palygorskites Modified by 1, 10-Phenanthroline and Triethylamine

2010 ◽  
Vol 178 ◽  
pp. 8-16
Author(s):  
Liang Dong Feng ◽  
Bo Qing Chen ◽  
Ying Ying Shi ◽  
Ying Wei Guo ◽  
Jing Huang ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Contact Time ◽  
Ph Value ◽  
Order Model ◽  
Kinetics Of Adsorption ◽  
Initial Concentration ◽  
Adsorption Capacities ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Kinetics Of

1, 10-phenanthroline and triethylamine modified palygorskites were prepared by microwave irradiation, and characterized with FT-IR technique. The effects of contact time, adsorbent dosage, and pH value of the initial solution on the adsorption characters of Mn2+ were investigated. The adsorption of Mn2+ from aqueous solutions using 1, 10-phenanthroline or triethylamine modified palygorskites were investigated. Experiment results indicated that 1,10-phenanthroline and triethylamine molecules have been successfully grafted to palygorskite. The adsorption was rapid during the first 5 minuts and equilibrium were attained within 60 minutes in the initial concentration of Mn2+ of 50 and 100 mg•L-1, and fast adsorption in the first 10 minutes and slowly increased with the contact time due to the adsorption of palygorskite. The 1, 10-phenanthroline modified palygorskites had higher adsorption capacity than triethylamine modified palygorskites. Compared with natural palggorskites, the Mn2+ ions adsorption capacities of palggorskite modified by 1, 10-phenanthroline or triethylamine were significantly improved. There were less difference in the adsorption capacity between different dasages of 1, 10-phenanthroline modified palygorskites, but the adsorption capacity of Mn2+ adsorbed onto triethylamine modified palygorskites decreased with increasing the dosages. A Lagergren pseudo-second order model best described the kinetics of adsorption of Mn2+ onto the modified palygorskites.

Adsorption of 2,4-Dichlorophenol on Meta-Aramid/Poly (acylic Acid) Composite Nanofibrous Membranes

2012 ◽  
Vol 610-613 ◽  
pp. 551-555 ◽  
Author(s):  
Qi Jun Zhou ◽  
Ran Xu
Keyword(s):  
Adsorption Capacity ◽  
Contact Time ◽  
Removal Rate ◽  
Freundlich Isotherm ◽  
Acidic Ph ◽  
Order Model ◽  
Electrospinning Method ◽  
Pseudo Second Order ◽  
Equilibrium Adsorption Capacity ◽  
Nanofibrous Membranes

Meta-aramid/poly (acylic acid) (PMIA/PAA) composite nanofibrous membranes with diameter between 50-100 nm have been fabricated by electrospinning method. The effect of contact time, temperature, pH and concentration of 2,4-dichlorophenol on the adsorption capacity of the membranes were investigated. The equilibrium adsorption capacity of 2,4-dichlorophenol on PMIA/PAA nanofibrous membranes is 251.61 mg/g. Acidic pH was favorable for the 2,4-dichlorophenol adsorption. Its desorption rate reached 74% in 45 min. After five regeneration cycles, the removal rate of 2,4-dichlorophenol still maintained above 65%. The adsorption of 2,4-dichlorophenol on the membranes fit the Freundlich isotherm model best. Its adsorption kinetics followed a pseudo-second-order model.

Characterizing o- and p-nitrophenols adsorption onto innovative activated carbon prepared from date pits

2013 ◽  
Vol 69 (1) ◽  
pp. 31-37 ◽  
Author(s):  
Hossam Altaher ◽  
Andrea M. Dietrich
Keyword(s):  
Activated Carbon ◽  
Adsorption Capacity ◽  
Adsorption Process ◽  
Waste Product ◽  
Considerable Effect ◽  
Surface Functional Groups ◽  
Order Model ◽  
Pseudo Second Order ◽  
And Performance ◽  
Date Pits

The production and performance of activated carbon prepared from date pits was investigated. Date pits are an abundant local waste product in many countries; converting them to a commercial product would increase the sustainability of this fruit crop. The date pit activated carbon was shown to have similar characteristics of pore size and surface functional groups as other commercial carbons. Batch experiments were conducted with o- and p-nitrophenol to evaluate the performance of this carbon. Results were analyzed according to Langmuir, Freundlich, and Dubinin-Radushkevich adsorption isotherms. The adsorption capacity of o-nitrophenol was 142.9 mg/g while that of p-nitrophenol was 108.7 mg/g. The adsorption process was physical in nature. The position of the −NO2 group in the benzene ring has a considerable effect on the adsorption capacity and rate of uptake. The kinetic results showed that a pseudo second-order model appropriately describes the experimental data. The analysis of kinetic data revealed that the mechanism of adsorption is complex with both liquid film diffusion and intraparticle diffusion contributing to adsorption of both adsorbates.

Adsorption Characteristics of Triclosan on Chitosan/Poly(vinyl alcohol) Composite Nanofibrous Membranes

2013 ◽  
Vol 448-453 ◽  
pp. 134-138
Author(s):  
Si Jia Liu ◽  
Ran Xu
Keyword(s):  
Adsorption Capacity ◽  
Vinyl Alcohol ◽  
Contact Time ◽  
Removal Rate ◽  
Poly Vinyl Alcohol ◽  
Order Model ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Equilibrium Adsorption Capacity ◽  
Nanofibrous Membranes

Chitosan/Poly (vinyl alcohol) (CS/PVA) composite nanofibrous membranes with diameter between 150-350 nm have been fabricated by electrospinning. The effect of contact time, temperature, pH and concentration of triclosan on the adsorption capacity of the membranes were investigated. The equilibrium adsorption capacity of triclosan on CS/PVA nanofibrous membranes was 61.61 mg/g. The favorable pH for triclosan adsorption was pH 6. After five regeneration cycles, the removal rate of triclosan maintained above 67%. The adsorption of triclosan on the membranes fitted both Freundlich and Langmuir isotherm model. Its adsorption kinetics followed a pseudo-second-order model.

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