scholarly journals Fabrication of Cellulose Nanocrystal-g-Poly(Acrylic Acid-Co-Acrylamide) Aerogels for Efficient Pb(II) Removal

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 333 ◽  
Author(s):  
Yifan Chen ◽  
Qian Li ◽  
Yujie Li ◽  
Qijun Zhang ◽  
Jingda Huang ◽  
...  
Keyword(s):  
Acrylic Acid ◽  
Adsorption Capacity ◽  
Langmuir Model ◽  
Cellulose Nanocrystal ◽  
Effective Removal ◽  
Pseudo Second Order ◽  
Repeated Use ◽  
Adsorption Desorption ◽  
Hydrolysis Of ◽  
Poly Acrylic Acid

In this work, cellulose nanocrystals (CNCs) obtained by the acid hydrolysis of waste bamboo powder were used to synthesize cellulose nanocrystal-g-poly(acrylic acid-co-acrylamide) (CNC-g-P(AA/AM)) aerogels via graft copolymerization followed by freeze-drying. The structure and morphology of the resulting aerogels were characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM), and the CNC-g-P(AA/AM) aerogels exhibited excellent absorbent properties and adsorption capacities. Subsequent Pb(II) adsorption studies showed that the kinetic data followed the pseudo-second-order equation, while the adsorption isotherms were best described using the Langmuir model. The maximum Pb(II) adsorption capacity calculated by the Langmuir model reached up to 366.3 mg/g, which is a capacity that outperformed that of the pure CNC aerogel. The CNC-g-P (AA/AM) aerogels become structurally stable through chemical cross-linking, which enabled them to be easily regenerated in HCl solution and retain the adsorption capacity after repeated use. The aerogels were found to maintain 81.3% removal efficiency after five consecutive adsorption–desorption cycles. Therefore, this study demonstrated an effective method for the fabrication of an aerogel adsorbent with an excellent reusability in the effective removal of Pb(II) from aqueous solutions.

scholarly journals Removal of Mercury(II) from Aqueous Solutions by Adsorption on Poly(1-amino-5-chloroanthraquinone) Nanofibrils: Equilibrium, Kinetics, and Mechanism Studies

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Shaojun Huang ◽  
Chengzhang Ma ◽  
Yaozu Liao ◽  
Chungang Min ◽  
Ping Du ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Photoelectron Spectroscopy ◽  
Batch Adsorption ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Repeated Use ◽  
Real Wastewater ◽  
Adsorption Desorption ◽  
Order Rate Equation

Poly(1-amino-5-chloroanthraquinone) (PACA) nanofibrils were applied as novel nanoadsorbents for highly toxic mercury removal from aqueous solutions. A series of batch adsorption experiments were conducted to study the effect of adsorbent dose, pH, contact time, and metal concentration on Hg(II) uptake by PACA nanofibrils. Kinetic data indicated that the adsorption process of PACA nanofibrils for Hg(II) achieved equilibrium within 2 h following a pseudo-second-order rate equation. The adsorption mechanism of PACA nanofibrils for Hg(II) was investigated by Fourier transform-infrared (FT-IR) spectra and X-ray photoelectron spectroscopy (XPS) analyses. The adsorption isotherm of Hg(II) fitted well the Langmuir model, exhibiting superb adsorption capacity of 3.846 mmol of metal per gram of adsorbent. Lastly, we found out that the as-synthesized PACA nanofibrils are efficient in Hg(II) removal from real wastewater. Furthermore, five consecutive adsorption-desorption cycles demonstrated that the PACA nanofibrils were suitable for repeated use without considerable changes in the adsorption capacity.

Sorption of Ag+, Cu2+ on Thiol-Functionalized Poly (Acrylic Acid)/SiO2 Composite Nanofiber Membranes

2011 ◽  
Vol 356-360 ◽  
pp. 488-492
Author(s):  
Ran Xu ◽  
Min Jia ◽  
Feng Ting Li
Keyword(s):  
Acrylic Acid ◽  
Adsorption Capacity ◽  
Removal Rate ◽  
Sol Gel ◽  
Electrospinning Method ◽  
Composite Nanofiber ◽  
Pseudo Second Order ◽  
Nanofiber Membranes ◽  
Kinetics Of ◽  
Poly Acrylic Acid

Thiol-functionalized poly (acrylic acid)/SiO2 (PAA/SiO2) composite nanofiber membranes have been fabricated by a sol-gel electrospinning method and their adsorption capacity for Ag+, Cu2+ was investigated. Results showed the PAA/SiO2 fibers had a diameter between 300 nm-700 nm. FTIR results demonstrated that the mercapto groups have been introduced into the silica skeleton. The adsorption of Ag+, Cu2+ on the membranes fit the Redlich-Peterson isotherm model best. The equilibrium adsorption capacity of Ag+ (575.64 mg/g) on PAA/SiO2 nanofiber membranes is higher than Cu2+ (331.52 mg/g). The desorption rate reached 98% in 30 min. The removal rate of Ag+, Cu2+ still maintained above 75% after six regeneration cycles. Adsorption kinetics of Ag+, Cu2+ followed a pseudo-second-order model.

scholarly journals Effect of Sodium Benzenesulfonate on SO42− Removal from Water by Polypyrrole-Modified Activated Carbon

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Feng Zhang ◽  
Dong-Sheng Wang ◽  
Fan Yang ◽  
Tian-Yu Li ◽  
Hong-Yan Li ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Adsorption Capacity ◽  
Granular Activated Carbon ◽  
Langmuir Model ◽  
Sulfate Adsorption ◽  
Modified Activated Carbon ◽  
Pseudo Second Order ◽  
Acidic Conditions ◽  
Adsorption Desorption ◽  
Desorption Cycle

Sodium benzenesulfonate was doped into polypyrrole-modified granular activated carbon (pyrrole-FeCl3·(6H2O)-sodium benzenesulfonate-granular activated carbon; PFB-GAC) with the goal of improving the modified GAC’s ability to adsorb sulfate from aqueous solutions. At a GAC dosage of 2.5 g and a pyrrole concentration of 1 mol L−1, the adsorption capacity of PFB-GAC prepared using a pyrrole:FeCl3·(6H2O):sodium benzenesulfonate ratio of 1000 : 1500 : 1 reached 23.05 mg g−1, which was eight times higher than that for GAC and two times higher than that for polypyrrole-modified GAC without sodium benzenesulfonate. Adsorption was favored under acidic conditions and high initial sulfate concentrations. Doping with sodium benzenesulfonate facilitated polymerization to give polypyrrole. Sodium benzenesulfonate introduced more imino groups to the polypyrrole coating, and the N+ sites improved ion exchange of Cl− and SO42− and increased the adsorption capacity of sulfate. Adsorption to the PFB-GAC followed pseudo-second-order kinetics. The adsorption isotherm conformed to the Langmuir model, and adsorption was exothermic. Regeneration using a weak alkali (NH3·H2O), which released OH− slowly, caused less damage to the polypyrrole than using a strong alkali (NaOH) as the regeneration reagent. NH3·H2O at a concentration of 12 mol L−1 (with the same OH− concentration as 2 mol L−1 NaOH) released 85% of the sorbed sulfate in the first adsorption-desorption cycle, and the adsorption capacity remained >6 mg g−1after five adsorption-desorption cycles.

A Novel Chelating Resin, Polystyrene-Supported Glucosamine: Preparation and Adsorption Properties for Ag(Ⅰ)

2011 ◽  
Vol 197-198 ◽  
pp. 478-482
Author(s):  
Hai Lan Huang ◽  
Guo Ming Wang ◽  
Rong Jun Qu ◽  
Xu Bo
Keyword(s):  
Adsorption Capacity ◽  
Considerable Change ◽  
Adsorption Properties ◽  
Langmuir Model ◽  
Chelating Resin ◽  
Isothermal Process ◽  
Adsorption Dynamics ◽  
Freundlich Model ◽  
Repeated Use ◽  
Adsorption Desorption

A novel chelating resin, crosslinking polystyrene-supported glucosamine (PS-GA), was prepared and its static adsorption properties for Ag(Ⅰ) were studied. The results indicated that this resin had excellent adsorption capacity for Ag(Ⅰ). The adsorption dynamics indicated that adsorption was controlled by the liquid film diffusion and the apparent activation energy Ea was 11.83 kJ/mol. Both Langmuir model and Freundlich model could describe the adsorption isothermal process of Ag(Ⅰ), and ∆G, ∆H, ∆S values were calculated. Increasing the temperature was beneficial to adsorption. The chelating resin can be easily regenerated by 2% thiourea in 0.1 mol/L HNO3 with higher effectiveness. Five adsorption–desorption cycles demonstrated that this resin was suitable for repeated use without considerable change in adsorption capacity.

scholarly journals Adsorption of Cadmium Ions from an Aqueous Solution on a Highly Stable Dopamine-Modified Magnetic Nano-Adsorbent

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Ting Lei ◽  
Sheng-Jian Li ◽  
Fang Jiang ◽  
Zi-Xuan Ren ◽  
Li-Lian Wang ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Adsorption Capacity ◽  
Magnetic Nanomaterials ◽  
Maximum Adsorption Capacity ◽  
Cadmium Ions ◽  
Effective Removal ◽  
Dopamine Hydrochloride ◽  
Pseudo Second Order ◽  
Adsorption Desorption ◽  
Nano Adsorbent

Abstract Magnetic nanomaterials were functionalized with dopamine hydrochloride as the functional reagent to afford a core–shell-type Fe3O4 modified with polydopamine (Fe3O4@PDA) composite, which was used for the adsorption of cadmium ions from an aqueous solution. In addition, the effects of environmental factors on the adsorption capacity were investigated. Furthermore, the adsorption kinetics, isotherm, and thermodynamics of the adsorbents were discussed. Results revealed that the adsorption of cadmium by Fe3O4@PDA reaches equilibrium within 120 min, and kinetic fitting data are consistent with the pseudo-second-order kinetics (R2 > 0.999). The adsorption isotherm of Cd2+ on Fe3O4@PDA was in agreement with the Freundlich model, with the maximum adsorption capacity of 21.58 mg/g. The thermodynamic parameters revealed that adsorption is inherently endothermic and spontaneous. Results obtained from the adsorption–desorption cycles revealed that Fe3O4@PDA exhibits ultra-high adsorption stability and reusability. Furthermore, the adsorbents were easily separated from water under an enhanced external magnetic field after adsorption due to the introduction of an iron-based core. Hence, this study demonstrates a promising magnetic nano-adsorbent for the effective removal of cadmium from cadmium-containing wastewater. Graphical Abstract

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

Molecules ◽  
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.

scholarly journals Preparation of bio-absorbents by modifying licorice residue via chemical methods and removal of copper ions from wastewater

2021 ◽  
Author(s):  
Xiaochun Yin ◽  
Nadi Zhang ◽  
Meixia Du ◽  
Hai Zhu ◽  
Ting Ke
Keyword(s):  
Adsorption Capacity ◽  
Copper Ions ◽  
Order Kinetic ◽  
Solution Ph ◽  
Chemical Methods ◽  
Simple Strategy ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Surface Active ◽  
Adsorption Desorption

Abstract In this paper, a series of bio-adsorbents (LR-NaOH, LR-Na2CO3 and LR-CA) were successfully prepared by modifying Licorice Residue with NaOH, Na2CO3 and citric acid, which were used as the adsorbents to remove Cu2+ from wastewater. The morphology and structure of bio-adsorbents were characterized by Fourier Transform Infrared, SEM, TG and XRD. Using static adsorption experiments, the effects of the adsorbent dosage, the solution pH, the adsorption time, and the initial Cu2+ concentration on the adsorption performance of the adsorbents were investigated. The results showed that the adsorption process of Cu2+ by the bio-adsorbents can be described by pseudo-second order kinetic model and the Langmuir model. The surface structure of the LR-NaOH, LR-Na2CO3 and LR-CA changed obviously, and the surface-active groups increased. The adsorption capacity of raw LR was 21.56 mg/g, LR-NaOH, LR- Na2CO3 significantly enhanced this value up to 43.65 mg/g, 43.55 mg/g, respectively. After four adsorption-desorption processes, the adsorption capacity of LR-NaOH also maintained about 73%. Therefore, LR-NaOH would be a promising adsorbent for removing Cu2+ from wastewater, and the simple strategy towards preparation of adsorbent from the waste residue can be as a potential approach using in the water treatment.

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