Equilibrium, Kinetic and Thermodynamic Studies on Methylene Blue Adsorption by Konjac Glucomannan/Activated Carbon Aerogel

Wang, Yuqi; Li, Yanhui; Hong, Liang; Zheng, Hairong; Du, Qiuju

doi:10.1007/s10924-019-01420-3

Cited by 27 publications

(5 citation statements)

References 38 publications

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“…The method of dye sorption allows one to more accurately assess the surface area of solids accessible to the reactants compared with low-temperature desorption of gas (nitrogen or steam), as a dye molecule is larger than a gas molecule. The application of this method is limited by solubility in water or water regain by the biomass, whereas water is used as a solvent in the existing dye sorption procedures [20][21][22].…”

Section: Introductionmentioning

confidence: 99%

Sorption of Methylene Blue for Studying the Specific Surface Properties of Biomass Carbohydrates

et al. 2020

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The surface area is an important parameter in setting any biorefining technology. The aim of this study was to investigate the applicability of sorption of methylene blue to characterize the surface of the main biomass carbohydrates: α-cellulose, sigmacell cellulose, natural gum, β-glucan, and starch. The morphology of particles of the model objects was studied by scanning electron microscopy. Nitrogen adsorption isotherms demonstrate that the selected carbohydrates are macroporous adsorbents. The monolayer capacities, the energy constants of the Brunauer–Emmett–Teller (BET) equation, and specific surface areas were calculated using the BET theory, the comparative method proposed by Gregg and Sing, and the Harkins–Jura method. The method of methylene blue sorption onto biomass carbohydrates was adapted and mastered. It was demonstrated that sorption of methylene blue proceeds successfully in ethanol, thus facilitating surface characterization for carbohydrates that are either soluble in water or regain water. It was found that the methylene blue sorption values correlate with specific surface area determined by nitrogen adsorption/desorption and calculated from the granulometric data. As a result of electrostatic attraction, the presence of ion-exchanged groups on the analyte surface has a stronger effect on binding of methylene blue than the surface area does. Sorption of methylene blue can be used in addition to gas adsorption/desorption to assess the accessibility of carbohydrate surface for binding large molecules.

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Section: Introductionmentioning

confidence: 99%

Sorption of Methylene Blue for Studying the Specific Surface Properties of Biomass Carbohydrates

et al. 2020

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“…The results are shown in Figure 5b, it can be seen that the adsorption capacity of THAM‐2 gels decreased with the increase of gel dose. These results could be the aggregation of adsorption sites and prolongation of diffusion path length, which issue in a decrease in the total available surface area 3,52 . However, the removal rate increased with the increase of gel dose.…”

Section: Resultsmentioning

confidence: 98%

“…These results could be the aggregation of adsorption sites and prolongation of diffusion path length, which issue in a decrease in the total available surface area. 3,52 However, the removal rate increased with the increase of gel dose. Total pore volume (cm 3 When the gel dose was 0.2 g L −1 , the adsorption capacity and removal rate of THAM-2 gels reached 1832 mg g −1 and 91.6%, respectively, with excellent adsorption performance and higher removal rate at a lower dose.…”

Section: Effect Of Gel Dosementioning

confidence: 96%

Hydroxyethyl cellulose hydrogel modified with tannic acid as methylene blue adsorbent

Feng

Zhang

Kang

et al. 2020

J of Applied Polymer Sci

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This work developed an effective way to improve the methylene blue (MB) adsorption performance of cellulose-based hydrogel by modified with tannic acid (TA). HEC-co-p(AA-AM)/TA hydrogel was synthesized by grafting of acrylic acid (AA) and acrylamide (AM) onto hydroxyethyl cellulose (HEC), followed by modified with TA. Fourier transform infrared spectroscopy manifested that AA and AM were successfully grafted onto the hydrogel, and TA was immobilized in the hydrogel. Field emission scanning electron microscope demonstrated that the hydrogel after TA modification had a homogeneous pore structure. Brunauer-Emmett-Teller (BET) surface areas, total pore volume, and average pore diameters of the hydrogel are 11.821 m 2 g −1 , 0.0641 cm 3 g −1 , and 2.538 nm, respectively. The high swelling ratio (1179.2 g g −1 in deionized water) was in favor of the MB adsorption. The results of the adsorption experiments illustrated that HEC-cop (AA/AM) hydrogel had excellent MB adsorption performance. As the pH increases, the electrostatic attraction is enhanced, and the adsorption capacity is improved. The adsorption process was more fit with pseudo-second-order kinetics, and the maximum adsorption capacity (3438.27 mg g −1) was determined by Langmuir model. Thermodynamic studies suggested that the adsorption process is spontaneous, exothermic, and entropy reduction. X-ray photoelectron spectroscopy analysis confirmed that MB molecules were reacted with the oxygen atoms in hydroxyl and carboxyl groups by ion-exchange. High reusability demonstrated that the hydrogel could be a potential candidate for removal cationic dye from industrial effluents.

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“…Adsorption thermodynamic evaluation. According to the influence of temperature on DO-26 dye adsorption and Van′t Hoff equation, the thermodynamic parameters, the changes of enthalpy (∆H), entropy (∆S), and Gibbs free energy(∆G), are calculated to evaluate the adsorption properties [18].…”

Section: Resultsmentioning

confidence: 99%

Preparation of Magnetic Alginate-Based Biogel Composite Cross-Linked by Calcium Ions and its Super Efficient Adsorption for Direct Dyes

Li¹,

Lin²

2021

MSF

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Magnetic sodium alginate (SA)-based biosorbent Fe₃O₄@SA-Ca gel beads were synthesized by droplet polymerization using Ca2+ ions as crosslinking agent, and characterized by Scanning Electron Microscopy (SEM). Fe₃O₄@SA-Ca polymer was used for the removal of Direct Orange 26 (DO-26) dye from water. The ratio of raw materials and some important conditions affecting the adsorbent performance were carefully examined. The adsorption kinetics, isotherms and thermodynamics were investigated. When the concentrations of SA, CaCl2 and Fe3O4 solutions were 1.9, 10 and 10 g/L, respectively, the black Fe₃O₄@SA-Ca gel beads with about 3 mm diameter were successfully prepared by curing 6h at room temperature. The polymer gel exhibits ultra-high adsorption capacity of 1252 mg/g and removal efficiency of 96.2 % for DO-26 under the conditions of 0.05 g polymer dosage, 2600 mg/L of dye initial concentration, solution pH 2.0 and 90 min of the adsorption time at 298 K. The dye removal efficiency can be all over 92 % in a wide pH range of 2.0 to 10.0. The adsorption process completely accorded with the pseudo-second-order rate model at different temperatures (298 ~ 328 K). The dye adsorption behavior was well in line with Freundlich model. The thermodynamic study indicated that the adsorption reaction was of spontaneous and exothermic nature. SEM analysis showed that the Fe₃O₄@SA-Ca gel beads appeared uneven surface with irregular folds and grooves. A high-cost-effective magnetic biosorbent, Fe₃O₄@SA-Ca can super effectively remove direct dyes from high-concentration wastewater in a wide range of acidity, and can be easily separated and recovered from water after adsorption without secondary pollution, and would have a good application prospect.

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Equilibrium, Kinetic and Thermodynamic Studies on Methylene Blue Adsorption by Konjac Glucomannan/Activated Carbon Aerogel

Cited by 27 publications

References 38 publications

Sorption of Methylene Blue for Studying the Specific Surface Properties of Biomass Carbohydrates

Sorption of Methylene Blue for Studying the Specific Surface Properties of Biomass Carbohydrates

Hydroxyethyl cellulose hydrogel modified with tannic acid as methylene blue adsorbent

Preparation of Magnetic Alginate-Based Biogel Composite Cross-Linked by Calcium Ions and its Super Efficient Adsorption for Direct Dyes

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