The Physiochemical Properties and Adsorption Characteristics of Processed Pomelo Peel as a Carrier for Epigallocatechin-3-Gallate

The NaOH-HCl- and ethanol-pretreated pomelo peel samples were prepared to apply to the batch adsorption for epigallocatechin-3-gallate (EGCG). The characteristics of peel samples were determined by Fourier transform infrared spectroscopy, scanning electron microscopy and a laser particle analyzer. The results of the physiochemical properties of the peel samples demonstrate that these peel samples have a promising adsorption capacity for EGCG, because of the increased potential binding sites on the surface compared with those of untreated peel samples. These two peel samples showed enhanced adsorption capacities of EGCG compared with that of unmodified peel in terms of the isothermal adsorption process, which could be described by both Langmuir and Freundlich models, with the theoretical maximum adsorption capacity of 77.52 and 94.34 mg g−1 for the NaOH-HCl and ethanol-treated peel samples, respectively. The adsorption kinetics demonstrated an excellent fitness to pseudo-second-order, showing that chemisorption was the rate-limiting step. The thermodynamics analysis revealed that the adsorption reaction was a spontaneous and endothermic process. This work highlights that the processed pomelo peels have outstanding adsorption capacities for EGCG, which could be promising candidates for EGCG delivering in functional food application.

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Enhanced adsorption performance of methylene blue from aqueous solutions onto modified adsorbents prepared from sewage sludge

Water Science & Technology ◽

10.2166/wst.2018.351 ◽

2018 ◽

Vol 78 (4) ◽

pp. 803-813

Author(s):

Tao Chen ◽

Bo Yan ◽

Da-Mao Xu ◽

Li-li Li

Keyword(s):

Methylene Blue ◽

Sewage Sludge ◽

Adsorption Capacity ◽

Batch Adsorption ◽

Maximum Adsorption Capacity ◽

Order Model ◽

Adsorption Performance ◽

Pseudo Second Order ◽

Enhanced Adsorption ◽

Modified Adsorbents

Abstract In the present work, an attractive and creative adsorbent derived from sewage sludge was freshly fabricated via pyrolysis technology, followed by modification for improving the absorptive ability. First, the (NH4)2S2O8 modified pyrolytic sludge (MSAP) was selected from 19 modified pyrolytic sludges for the highest removal efficiency and adsorption capacity for methylene blue (MB). Then, the adsorption performance for MB of MSAP was compared systematically with the pristine adsorbent (MSDW) by batch adsorption experiments. The main conclusions were that the adsorption process was better fitted with the Langmuir model, and the maximum adsorption capacity (qmax) of MSAP was observed to be 149.05 mg g−1. Moreover, the adsorption kinetics data showed a good fit with the pseudo second order model; when the addition of MSAP was 1.0 g·L−1, the rate constant was 0.05 g·mg−1·min−1, which was far greater than that of the other modified adsorbents.

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Biochar of Spent Coffee Grounds as Per Se and Impregnated with TiO2: Promising Waste-Derived Adsorbents for Balofloxacin

Molecules ◽

10.3390/molecules26082295 ◽

2021 ◽

Vol 26 (8) ◽

pp. 2295

Author(s):

Marwa El-Azazy ◽

Ahmed S. El-Shafie ◽

Hagar Morsy

Keyword(s):

Adsorption Capacity ◽

Batch Adsorption ◽

Maximum Adsorption Capacity ◽

Spent Coffee Grounds ◽

Thermal Stabilities ◽

Coffee Grounds ◽

Bet Analysis ◽

Pseudo Second Order ◽

Set Up ◽

Adsorption Desorption

Biochars (BC) of spent coffee grounds, both pristine (SCBC) and impregnated with titanium oxide (TiO2@SCBC) were exploited as environmentally friendly and economical sorbents for the fluroquinolone antibiotic balofloxacin (BALX). Surface morphology, functional moieties, and thermal stabilities of both adsorbents were scrutinized using SEM, EDS, TEM, BET, FTIR, Raman, and TG/dT analyses. BET analysis indicated that the impregnation with TiO2 has increased the surface area (50.54 m2/g) and decreased the pore size and volume. Batch adsorption experiments were completed in lights of the experimental set-up of Plackett-Burman design (PBD). Two responses were maximized; the % removal (%R) and the adsorption capacity (qe, mg/g) as a function of four variables: pH, adsorbent dosage (AD), BALX concentration ([BALX]), and contact time (CT). %R of 68.34% and 91.78% were accomplished using the pristine and TiO2@SCBC, respectively. Equilibrium isotherms indicated that Freundlich model was of a perfect fit for adsorption of BALX onto both adsorbents. Maximum adsorption capacity (qmax) of 142.55 mg/g for SCBC and 196.73 mg/g for the TiO2@SCBC. Kinetics of the adsorption process were best demonstrated using the pseudo-second order (PSO) model. The adsorption-desorption studies showed that both adsorbents could be restored with the adsorption efficiency being conserved up to 66.32% after the fifth cycles.

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Calcium PretreatedHevea brasiliensisSawdust for Copper Removal: Batch and Column Study

Journal of Chemistry ◽

10.1155/2015/495257 ◽

2015 ◽

Vol 2015 ◽

pp. 1-9

Author(s):

Swarup Biswas ◽

Umesh Mishra

Keyword(s):

Adsorption Capacity ◽

Adsorption Process ◽

Copper Ion ◽

Packed Bed ◽

Isotherm Models ◽

Batch Adsorption ◽

Maximum Adsorption Capacity ◽

Packed Bed Column ◽

Pseudo Second Order ◽

Kinetics Of

Calcium pretreatedHevea brasiliensissawdust has been used as an effective and efficient adsorbent for the removal of copper ion from the contaminated water. Batch experiment was conducted to check the effect of pH, initial concentration, contact time, and adsorbent dose. The results conclude that adsorption capacity of adsorbent was influenced by operating parameters. Maximum adsorption capacity found from the batch adsorption process was 37.74 mg/g at pH of 5.6. Various isotherm models like Langmuir, Freundlich, and Temkin were used to compare the theoretical and experimental data, whereas the pseudo-first-order, pseudo-second-order, and intraparticle diffusion models were applied to study the kinetics of the batch adsorption process. Dynamic studies were also conducted in packed-bed column using different bed depths and the maximum adsorption capacity of 34.29 was achieved. Characterizations of the adsorbent were done by Fourier transform infrared spectroscopy, scanning electron microscope, and energy dispersive X-ray spectroscopy.

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A Novel Geopolymer Foam Based On ZSM-5 Zeolite Fabricated Using Templating Emulsion/Chemical Foaming Method and Its Application in Batch and Continuous Dye Removal Systems

10.21203/rs.3.rs-1227901/v1 ◽

2022 ◽

Author(s):

Mahboobeh Monjezi ◽

Vahid Javanbakht

Keyword(s):

Adsorption Capacity ◽

Dye Removal ◽

Adsorption Process ◽

Dye Adsorption ◽

Batch Adsorption ◽

Maximum Adsorption Capacity ◽

Continuous Systems ◽

Green Materials ◽

Pseudo Second Order ◽

Chemical Foaming

Abstract Geopolymers as sustainable and environmentally friendly “green materials”, can be synthesized by utilizing waste material and by-products. A porous geopolymer foam adsorbent based on ZSM-5 zeolite was prepared using templating emulsion/chemical foaming method in different conditions and used for dye removal in batch and continuous systems. The parameters affecting the dye adsorption including temperature, concentration, and pH, kinetics, isotherm, and thermodynamics of the process were investigated. The results of the geopolymer foam synthesis showed that thermal pretreatment of the zeolite has a positive effect on the strength and adsorption capacity. Moreover, the increase in sodium silicate more than the stoichiometric reduces the strength and adsorption capacity. The findings obtained from the batch adsorption process showed that the adsorption kinetics of the pseudo-second-order model and the adsorption isotherm of the Temkin model is adjusted with the experimental data. Thermodynamic results indicated that the process of dye adsorption with geopolymer foam is exothermic. The results from continuous experiments indicated more compatibility of the adsorption process with the models of Thomas and Bohart-Adams. The maximum adsorption capacity of methylene blue in batch and continuous processes was 9.82 and 8.17 mg/g. The adsorbent reduction was performed successfully by chemical and thermal processes.

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Synthesis of magnetic biochar derived from cotton stalks for the removal of Cr(VI) from aqueous solution

Water Science & Technology ◽

10.2166/wst.2019.208 ◽

2019 ◽

Vol 79 (11) ◽

pp. 2106-2115 ◽

Cited By ~ 3

Author(s):

Fengfeng Ma ◽

Baowei Zhao ◽

Jingru Diao

Keyword(s):

Adsorption Capacity ◽

Photoelectron Spectroscopy ◽

Batch Adsorption ◽

Maximum Adsorption Capacity ◽

Cotton Stalk ◽

Magnetic Biochar ◽

X Ray ◽

Cotton Stalks ◽

Pseudo Second Order ◽

Co Precipitation

Abstract A magnetic cotton stalk biochar (MCSBC) was synthesized through chemical co-precipitation, based on cotton stalk biochar (CSBC). The MCSBC and CSBC were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy and vibrating sample magnetometry. The characterization analyses showed that the magnetization process endowed the CSBC with excellent magnetic properties with a superparamagnetic magnetization of 27.59 emu/g. Batch adsorption experiment results indicated that the Cr(VI) maximum adsorption capacity of MCSBC was 20.05 mg/g, which was higher than that of CSBC (18.77 mg/g). The adsorption kinetic data were well fitted by the pseudo-second-order model and the adsorption isotherms were well represented by the Sips isotherm model. The thermodynamic studies indicated that the adsorption process was spontaneous and endothermic, and the entropy increased. The potential adsorption mechanism was the electrostatic adsorption of anionic Cr(VI) to the positively charged MCSBC surface, the reduction of Cr(VI) into Cr(III) and the complexation of Cr(III) by oxygen-containing functional groups of MCSBC. The regeneration studies showed that MCSBC kept 80% of its initial Cr(VI) adsorption capacity in the cycle. All the findings suggest that this novel magnetic biochar could be used in the field of Cr(VI)-containing wastewater treatment.

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Development of Natural Cation Exchanger for the Treatment of Lead ions from Aqueous Solution

Journal of Nepal Chemical Society ◽

10.3126/jncs.v29i0.9235 ◽

2013 ◽

Vol 29 ◽

pp. 34-43

Author(s):

Puspa Lal Homagai

Keyword(s):

Adsorption Capacity ◽

Sugarcane Bagasse ◽

Active Sites ◽

Freundlich Isotherm ◽

Saccharum Officinarum ◽

Isotherm Models ◽

Batch Adsorption ◽

Maximum Adsorption Capacity ◽

Fast Kinetics ◽

Pseudo Second Order

Cellulose, hemicelluloses and lignin are the main constituents found in sugarcane (Saccharum officinarum) bagasse having many surface active sites containing hydroxyl and/or phenolic groups which are effective for chemical modification. The biowaste was first charred with concentrated sulphuric acid and then the charred aminated sugarcane bagasse (CASB) was prepared by reduction followed by oxidation. The developed bio-sorbent was characterized by SEM, TGA/DTA, FTIR and elemental analysis. Batch adsorption methods were carried out to determine Pb+2 sorption capacities at different pH ranges and sorbate concentrations. The maximum adsorption capacity for Pb+2 was found to be 323 mg g-1 with an efficiency of 98% at pH 4.The experimental data showed a good fit to Langmuir isotherm as compared to Freundlich isotherm models. The kinetics was best fitted with the pseudo-second order model. The adsorption equilibrium was attained within 20 min. The high adsorption capacity and fast kinetics results of the charred aminated sugarcane bagasse indicated that it might be potential adsorbent for the removal of lead from contaminated water. DOI: http://dx.doi.org/10.3126/jncs.v29i0.9235Journal of Nepal Chemical SocietyVol. 29, 2012Page: 34-43Uploaded date : 12/3/2013

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Cr(VI) Adsorption from Aqueous Solution by UiO-66 Modified Corncob

Sustainability ◽

10.3390/su132312962 ◽

2021 ◽

Vol 13 (23) ◽

pp. 12962

Author(s):

Hongzhong Xie ◽

Yanlei Wan ◽

Hao Chen ◽

Guangcheng Xiong ◽

Lingqing Wang ◽

...

Keyword(s):

Ionic Strength ◽

Adsorption Capacity ◽

Polluted Water ◽

Batch Adsorption ◽

Maximum Adsorption Capacity ◽

Mechanism Analysis ◽

Solution Ph ◽

Isothermal Adsorption ◽

Promising Application ◽

Ph Range

To adsorb hexavalent chromium (Cr(VI)) in polluted water, this paper prepared a UiO-66 (Zr6O4(OH)4(BDC)12) modified granular corncob composite adsorbent by hydrothermal method with in situ loading of UiO-66 on pretreated corncob particles. The physicochemical properties of the synthesized samples were characterized. Batch adsorption experiments were conducted to investigate the adsorption process of aqueous Cr(VI) under various conditions (different ionic strength, pH and co-existing anions). The results showed that UiO-66 was successfully loaded on the modified corncob particles. The isothermal adsorption data of Cr(VI) adsorption by the UiO-66 modified corncob fit well with the Langmuir model with the maximum adsorption capacity of Cr(VI) on UiO-66@Corn+ being 90.04 mg/g. UiO-66 loading could increase Cr(VI) adsorption capacity of Corn+. The kinetic study showed that the equilibrium time for Cr(VI) adsorption on UiO-66 modified corncob was about 180 min and the kinetic data followed the pseudo-secondary kinetic model. The Cr(VI) adsorption capacity on UiO-66@Corn+ decreased with the increasing solution pH, and the optimum pH range was 4–6. The ionic strength has little effect on the Cr(VI) adsorption capacity, but the coexistence of CO32−, SO42− and PO43− in the solution could significantly decrease the equilibrium adsorption capacity of Cr(VI). The adsorption mechanism analysis showed that Cr(VI) was adsorbed on the surface of adsorbents through electrostatic attraction and was reduced further to the less toxic Cr(III) by the electron donor on the surface of adsorbent. The electrostatic interaction was the main force affecting the adsorption of Cr(VI) by UiO-66. UiO-66@Corn+ had an excellent removal efficiency of Cr(VI) and excellent reusability. UiO-66@Corn+ could effectively remove Cr(VI) from water and have a promising application.

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Cu(II) and Cd(II) Removal from Aqueous Solution with LDH@GO-NH2 and LDH@GO-SH: Kinetics and Probable Mechanism

10.21203/rs.3.rs-157072/v1 ◽

2021 ◽

Author(s):

Wei Liao ◽

Di Bao ◽

Huiqiang Li ◽

Ping Yang

Keyword(s):

Adsorption Capacity ◽

Thiol Group ◽

Maximum Adsorption Capacity ◽

Isomorphic Substitution ◽

Temperature Dependent ◽

Adsorption Mechanisms ◽

Adsorption Processes ◽

Endothermic Process ◽

Pseudo Second Order ◽

Near Future

Abstract Two novel adsorbents of thiol- and amino-functionalized GO grafted onto LDH (LDH@GO-NH2 and LDH@GO-SH) were synthesized and contrasted for adsorption properties for Cu(II) and Cd(II). Characterization experiments illustrated that thiol group (-SH) and amino group (-NH2) were existed onto LDH@GO-NH2 and LDH@GO-SH. Adsorption isotherm results showed that the adsorption processes were satisfactorily fitted by both Langmuir and Freundlich models. The maximum adsorption capacity of Cd(II) on LDH@GO-SH at 308 K was 102.77 mg/g, which was about triple that of LDH@GO-NH2. The enhancement in adsorption capacity was due to the cooperative effect of LDH and GO-SH. The kinetic experimental data for LDH@GO-NH2 and LDH@GO-SH were found to be in good agreement with pseudo-second-order model. The thermodynamic parameters calculated from the temperature dependent adsorption isotherms indicated that the adsorption was a spontaneous and endothermic process. The possible adsorption mechanisms comprising formation of precipitation, isomorphic substitution of Mg(II), and formation of complexation with amino-groups and thiol-groups were proposed. Desorption experiments put into evidence that the LDH@GO-NH2 and LDH@GO-SH may be promising suitable candidates for the remediation of metal ions from aqueous solutions in real work in the near future.

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Adsorption of Dye from Wastewater by Modified Sawdust

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1065-1069.3123 ◽

2014 ◽

Vol 1065-1069 ◽

pp. 3123-3126

Author(s):

Gang Chao Zhu ◽

Jian Xin Shou ◽

Jia Wei Qian ◽

Hua Zheng Xin ◽

Mu Qing Qiu

Keyword(s):

Adsorption Capacity ◽

Contact Time ◽

Ph Value ◽

Langmuir Model ◽

Ammonium Bromide ◽

Maximum Adsorption Capacity ◽

Order Model ◽

Adsorption Processes ◽

Endothermic Process ◽

Pseudo Second Order

In this study, sawdust modified by cetyltimethyl ammonium bromide was applied to adsorb conge red in aqueous solutions. The characteristics of modified sawdust were characterized by Fourier transform infrared spectrum and scanning electron microscopy. The effect of factors, such as pH, contact time, temperature, dosage, and salt concentration, were investigated. The results revealed that the addition of modified sawdust can significantly increase the adsorption capacity of dye. The maximum adsorption capacity of dye on modified sawdust was 109 mg·g-1 at 328K. The adsorption processes were rapid within the first 30 min and reached equilibrium in about 150 min. The adsorption kinetics fitted well with pseudo-second-order model. The pH value of the solution had significant impact on the amount of adsorption. Adsorption isotherm fitted better with the Langmuir model and the adsorption was an endothermic process

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Microwave Enhanced Synthesis of Chitosan-graftMolecularly Imprinted Polymer (MIP) for Selective Extraction of Antioxidants

E-Journal of Chemistry ◽

10.1155/2010/402698 ◽

2010 ◽

Vol 7 (4) ◽

pp. 1362-1374 ◽

Cited By ~ 6

Author(s):

N. Saifuddin ◽

A. A. Nur Yasumira

Keyword(s):

Adsorption Capacity ◽

Selective Extraction ◽

Maximum Adsorption Capacity ◽

Imprinted Polymer ◽

Chitosan Beads ◽

Molecularly Imprinted ◽

Adsorption Models ◽

Adsorption Capacities ◽

Enhanced Adsorption ◽

Functional Matrix

Polymers have been molecularly imprinted for the purpose of binding specifically toα-tocotrienol (vitamin E). A molecularly imprinted polymer (MIP) material was prepared usingα-tocotrienol as the imprinted molecule, acrylamide as functional monomer and macroporous chitosan beads as functional matrix. Chitosan-graft-polyacrylamide was synthesized without any radical initiator or catalyst using microwave (MW) irradiation. The representative microwave synthesized graft copolymer was characterized by fourier transform-infrared spectroscopy, taking chitosan as a reference. Microwave irradiation was exploited for polyacrylamide grafting on the cross-linked chitosan beads to produce MIP, where both time as well as chemicals can be saved. It can be assumed that the chitosan coated polyacrylamide MIP will have better pH stability and enhanced adsorption capacity. The maximum adsorption capacity was observed to be 3.95 mg/g of MIP, which gave removal efficiency of 93%. After 4 h, the change of adsorption capacities forα-tocotrienol did not show notable effects. The Langmuir and Freundlich adsorption models were also applied to describe the equilibrium isotherms.

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