Highly Effective Covalently Crosslinked Composite Alginate Cryogels for Cationic Dye Removal

Currently, macroporous hydrogels have been receiving attention in wastewater treatment due to their unique structures. As a natural polymer, alginate is used to remove cationic dyes due to its sustainable features such as abundance, low cost, processability, and being environmentally friendly. Herein, alginate/montmorillonite composite macroporous hydrogels (cryogels) with high porosity, mechanical elasticity, and high adsorption yield for methylene blue (MB) were generated by the one-step cryogelation technique. These cryogels were synthesized by adding montmorillonite into gel precursor, followed by chemical cross-linking employing carbodiimide chemistry in a frozen state. The as-prepared adsorbents were analyzed by FT-IR, SEM, gel fraction, swelling, uniaxial compression, and MB adsorption tests. The results indicated that alginate/montmorillonite cryogels exhibited high gelation yield (up to 80%), colossal water uptake capacity, elasticity, and effective dye adsorption capacity (93.7%). Maximum adsorption capacity against MB was 559.94 mg g−1 by linear regression of Langmuir model onto experimental data. The Pseudo-Second-Order model was fitted better onto kinetic data compared to the Pseudo-First-Order model. Improved porosity and mechanical elasticity yielding enhanced dye removal capacity make them highly potential alternative adsorbents compared to available alginate/montmorillonite materials for MB removal.

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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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Kinetic and equilibrium studies on adsorption of Reactive Blue 19 dye from aqueous solutions by nanohydroxyapatite adsorbent

Archives of Environmental Protection ◽

10.1515/aep-2016-0014 ◽

2016 ◽

Vol 42 (2) ◽

pp. 3-11 ◽

Cited By ~ 22

Author(s):

Gabriela Ciobanu ◽

Simona Barna ◽

Maria Harja

Keyword(s):

Dye Removal ◽

Dye Adsorption ◽

Kinetic Studies ◽

Solution Concentration ◽

Batch Adsorption ◽

Maximum Adsorption Capacity ◽

Order Model ◽

Equilibrium Studies ◽

Reactive Blue 19 ◽

Pseudo Second Order

AbstractIn the present study the adsorption of Reactive Blue 19 dye on the hydroxyapatite (HAp) nanopowders was investigated. The batch adsorption experiments were performed by monitoring the adsorbent dosage, contact time, dye solution concentration, pH and temperature. At pH 3 and 20°C, high dye removal rates of about 95.58% and 86.95% for the uncalcined and calcined nanohydroxyapatites, respectively, were obtained. The kinetic studies indicated the dye adsorption onto nanohydroxyapatite samples to follow a pseudo-second order model. The Langmuir isotherm was found to be the best to represent the equilibrium with experimental data. The maximum adsorption capacity of uncalcined and calcined nanohydroxyapatite samples has been found to be 90.09 mg/g and 74.97 mg/g, respectively.

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

Molecules ◽

10.3390/molecules23092218 ◽

2018 ◽

Vol 23 (9) ◽

pp. 2218 ◽

Cited By ~ 6

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.

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Preparation of bio-based magnetic adsorbent and application for efficient removal of Cd(II) from water

Water Science & Technology ◽

10.2166/wst.2018.007 ◽

2018 ◽

Vol 77 (5) ◽

pp. 1313-1323 ◽

Cited By ~ 1

Author(s):

Jianjun Zhou ◽

Xionghui Ji ◽

Xiaohui Zhou ◽

Jialin Ren ◽

Yaochi Liu

Keyword(s):

Aqueous Solution ◽

Adsorption Process ◽

Low Cost ◽

Maximum Adsorption Capacity ◽

Magnetic Adsorbent ◽

Order Model ◽

Efficient Removal ◽

Adsorption Ability ◽

Adsorption Sites ◽

Pseudo Second Order

Abstract A novel magnetic bio-adsorbent (MCIA) was developed, characterized and tested for its Cd(II) removal from aqueous solution. MCIA could be easily separated from the solution after equilibrium adsorption due to its super-paramagnetic property. The functional and magnetic bio-material was an attractive adsorbent for the removal of Cd(II) from aqueous solution owing to the abundant adsorption sites, amino-group and oxygen-containing groups on the surface of Cyclosorus interruptus. The experimental results indicated that the MCIA exhibited excellent adsorption ability and the adsorption process was spontaneous and endothermic. The adsorption isotherm was consistent with the Langmuir model. The adsorption kinetic fitted the pseudo-second-order model very well. The maximum adsorption capacity of Cd(II) onto MCIA was 40.8, 49.4, 54.6 and 56.6 mg/g at 293, 303, 313 and 323 K, respectively. And the MCIA exhibited an excellent reusability and impressive regeneration. Therefore, MCIA could serve as a sustainable, efficient and low-cost magnetic adsorbent for Cd(II) removal from aqueous solution.

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Removal of Crystal Violet Dye from Aqueous Solutions onto Date Palm Fiber by Adsorption Technique

Journal of Chemistry ◽

10.1155/2013/210239 ◽

2013 ◽

Vol 2013 ◽

pp. 1-6 ◽

Cited By ~ 24

Author(s):

Mashael Alshabanat ◽

Ghadah Alsenani ◽

Rasmiah Almufarij

Keyword(s):

Crystal Violet ◽

Date Palm ◽

Dye Removal ◽

Adsorption Process ◽

Maximum Adsorption Capacity ◽

Order Model ◽

Date Palm Fibers ◽

Crystal Violet Dye ◽

Pseudo Second Order ◽

Influence Of Ph

The adsorption of crystal violet (CV) onto date palm fibers (DPFs) was examined in aqueous solution at 25°C. The experimental maximum adsorption capacity value was0.66×10−6. Langmuir, Freundlich, Elovich and Temkin models were applied to describe the equilibrium isotherms. The influence of pH and temperature on dye removal was evaluated. The percentage removal of CV dye by adsorption onto DPF at different pH and temperatures showed that these factors play a role in the adsorption process. Thermodynamic analysis was performed, and the Gibbs free energyΔGο, enthalpy changeΔHο, and entropyΔSοwere calculated. The negative values ofΔGοindicate spontaneous adsorption. The negative value ofΔHοindicates that the interaction between CV and DPF is exothermic, and the positive value ofΔSοindicates good affinity between DPF and CV. The kinetic data were fitted to a pseudo-second-order model.

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Simultaneous Adsorption of Cr(VI) and Phenol from Binary Mixture Using Iron Incorporated Rice Husk: Insight to Multicomponent Equilibrium Isotherm

International Journal of Chemical Engineering ◽

10.1155/2016/7086761 ◽

2016 ◽

Vol 2016 ◽

pp. 1-11 ◽

Cited By ~ 4

Author(s):

Ankur Gupta ◽

Chandrajit Balomajumder

Keyword(s):

Experimental Data ◽

Rice Husk ◽

Low Cost ◽

Binary Solution ◽

Multicomponent System ◽

Isotherm Models ◽

Maximum Adsorption Capacity ◽

Order Model ◽

Adsorption Isotherm Models ◽

Pseudo Second Order

Fe modified rice husk was prepared as a low cost biosorbent for the removal of Cr(VI) and phenol both singly and in combination from single and binary simulated synthetic waste water. Rice husk was modified by treating with FeSO4·7H2O. The results showed that impregnation of iron onto the surface of rice husk improved the adsorption capability of both Cr(VI) and phenol. The effects of process parameters for multicomponent system such as pH, adsorbent dose, and contact time onto the percentage removal of both Cr(VI) and phenol were investigated. The experimental data for the adsorption of both Cr(VI) and phenol onto the surface of Fe modified rice husk applied to various kinetic and adsorption isotherm models. Multicomponent isotherm models such as Nonmodified Langmuir, Modified Langmuir, Extended Langmuir, Extended Freundlich, Competitive Nonmodified Redlich Peterson, Competitive Modified Redlich Peterson were applied. The results show that Extended Freundlich model best described the experimental data for both Cr(VI) and phenol from binary solution. Pseudo second-order model agreed well with Cr(VI) while pseudo first-order model agreed well with phenol. Maximum adsorption capacity in synthetic binary solution of Cr(VI) and phenol was found to be 36.3817 mg g−1for Cr(VI) and 6.569 mg g−1for phenol, respectively.

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Equilibrium, kinetic and thermodynamic studies of mercury adsorption on almond shell

Water Science & Technology ◽

10.2166/wst.2012.767 ◽

2012 ◽

Vol 65 (8) ◽

pp. 1341-1349 ◽

Cited By ~ 12

Author(s):

Shokooh Sadat Khaloo ◽

Amir Hossein Matin ◽

Sahar Sharifi ◽

Masoumeh Fadaeinia ◽

Narges Kazempour ◽

...

Keyword(s):

Adsorption Capacity ◽

Low Cost ◽

Second Order ◽

Ion Concentration ◽

Physical Parameters ◽

Maximum Adsorption Capacity ◽

Almond Shell ◽

Pseudo Second Order ◽

Uptake Process ◽

Reaction Equations

The application of almond shell as a low cost natural adsorbent to remove Hg2+ from aqueous solution was investigated. Batch experiments were carried out to evaluate the adsorption capacity of the material. The chemical and physical parameters such as pH, sorbent amount, initial ion concentration, and contact time were optimized for the maximum uptake of mercury onto the solid surface. Adsorption isotherms were expressed by Langmuir and Freundlich adsorption models, and the experimental data were found to fit the Langmuir model rather than the Freundlich. The maximum adsorption capacity obtained from the Langmuir isotherm was 135.13 mg/g. A kinetic study was carried out with pseudo-first-order and pseudo-second-order reaction equations and it was found that the Hg2+ uptake process followed the pseudo-second-order rate expression. The thermodynamic values, ΔG0, ΔH0 and ΔS0, indicated that adsorption was an endothermic and spontaneous process. The potential of this material for mercury elimination was demonstrated by efficient Hg2+ removal from a synthetic effluent.

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Syringa vulgaris leaves powder a novel low-cost adsorbent for methylene blue removal: isotherms, kinetics, thermodynamic and optimization by Taguchi method

Scientific Reports ◽

10.1038/s41598-020-74819-x ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Giannin Mosoarca ◽

Cosmin Vancea ◽

Simona Popa ◽

Marius Gheju ◽

Sorina Boran

Keyword(s):

Methylene Blue ◽

Low Cost ◽

Dye Adsorption ◽

Maximum Adsorption Capacity ◽

Order Kinetic ◽

Adsorbent Surface ◽

Order Kinetic Model ◽

Endothermic Process ◽

Pseudo Second Order ◽

Better Than

Abstract In this study, the potential of a new low-cost adsorbent, Syringa vulgaris leaves powder, for methylene blue adsorption from aqueous solution was investigated. The adsorbent surface was examined using SEM and FTIR techniques. The experiments were conducted, in batch system, to find out the effect of pH, contact time, adsorbent dose, initial dye concentration, temperature and ionic strength on dye adsorption. The process is best described by Langmuir isotherm and the pseudo second order kinetic model. Maximum adsorption capacity, 188.2 (mg g−1), is better than other similar adsorbent materials. Thermodynamic parameters revealed a spontaneous and endothermic process, suggesting a physisorption mechanism. A Taguchi orthogonal array (L27) experimental design was used to determine the optimum conditions for the removal of dye. Various desorbing agents were used to investigate the regeneration possibility of used adsorbent. Results suggest that the adsorbent material is very effective for removal of methylene blue from aqueous solutions.

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

Royal Society Open Science ◽

10.1098/rsos.191811 ◽

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.

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Ultrasound and microwave-assisted preparation of Fe-activated carbon as an effective low-cost adsorbent for dyes wastewater treatment

RSC Advances ◽

10.1039/c6ra14082c ◽

2016 ◽

Vol 6 (82) ◽

pp. 78936-78946 ◽

Cited By ~ 24

Author(s):

Song Cheng ◽

Libo Zhang ◽

Hongying Xia ◽

Jinhui Peng ◽

Jianhua Shu ◽

...

Keyword(s):

Wastewater Treatment ◽

Activated Carbon ◽

Adsorption Capacity ◽

Removal Efficiency ◽

Langmuir Isotherm ◽

Low Cost ◽

Order Model ◽

Microwave Assisted ◽

Pseudo Second Order ◽

Mb Adsorption

A and B are Langmuir isotherm and pseudo-second-order model. We conclude that MB adsorption capacity of Fe-activated carbon is bigger than raw activated carbon, indicating that Fe-activated carbon has better MB removal efficiency.

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