scholarly journals Environmentally Friendly Polyvinyl alcohol−alginate/bentonite Nanocomposite Hydrogel Beads as Efficient Adsorbents for Removal of Toxic Methylene Blue from Aqueous Solution

2021 ◽  
Author(s):  
Mona A. Aziz Aljar ◽  
Suad Rashdan ◽  
Ahmed Abd El-Fattah
Keyword(s):  
Methylene Blue ◽  
Polyvinyl Alcohol ◽  
Organic Dyes ◽  
Research Work ◽  
Polluted Water ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Nanocomposite Hydrogel ◽  
Homogeneous Surface ◽  
Hydrogel Beads

Hazardous chemicals like toxic organic dyes are very harmful to the environment and their removal is quite challenging. Therefore there is a necessity to develop techniques, which are environment friendly, cost-effective and easily available in nature for water purification and re-mediation. The present research work is focused on the development` and characterization of the ecofriendly polyvinyl alcohol (PVA) and alginate (Alg) hydrogel beads incorporating natural bentonite (Bent) clay as beneficial adsorbents for removal of toxic methylene blue (MB) from industrial water. PVA−Alg/Bent nanocomposite hydrogel beads with different Bent content (0, 10, 20, and 30 wt%) were synthesized via external ionic gelation method. The designed porous and steady structure beads were characterized by the use of Fourier transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDX), and scanning electron microscopy (SEM). The performance of the beads as MB adsorbents was investigated by treating batch aqueous solutions. The experimental results indicated that the incorporation of Bent (30 w%) in the nanocomposite formulation sustained porous structure, preserved water uptake, and increased MB removal effi-ciency by 230 % compared to empty beads. Designed beads possessed higher affinity to MB at high pH 8, 30 °C, and fitted well to pseudo-second-order kinetic model a high correlation coefficient. Moreover, designed beads had a good stability and reusability as they exhibited excellent removal efficiency (90%) after six consecutive adsorption-desorption cycles. Adsorption process was found be combination of both monolayer adsorption on homogeneous surface and multilayer adsorption on heterogeneous surface. The maximum adsorption capacity of the designed beads system as calculated by Langmuir isotherm was found to be 51.34 mg/g, which is in good agreement with the reported clay-related adsorbents. The designed PVA−Alg/Bent nanocomposite hydrogel beads demonstrated good adsorbent properties and could be potentially used for MB removal from polluted water.

scholarly journals Environmentally Friendly Polyvinyl Alcohol−Alginate/Bentonite Semi-Interpenetrating Polymer Network Nanocomposite Hydrogel Beads as An Efficient Adsorbent for the Removal of Methylene Blue from Aqueous Solution

Polymers ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 4000
Author(s):  
Mona A. Aziz Aljar ◽  
Suad Rashdan ◽  
Ahmed Abd El-Fattah
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Polyvinyl Alcohol ◽  
Removal Efficiency ◽  
Polymer Network ◽  
Interpenetrating Polymer Network ◽  
Polluted Water ◽  
Order Kinetic ◽  
Nanocomposite Hydrogel ◽  
Hydrogel Beads

Hazardous chemicals like toxic organic dyes are very harmful to the environment and their removal is quite challenging. Therefore there is a necessity to develop techniques, which are environment friendly, cost-effective and easily available in nature for water purification and remediation. The present research work is focused on the development` and characterization of the ecofriendly semi-interpenetrating polymer network (semi-IPN) nanocomposite hydrogels composed of polyvinyl alcohol (PVA) and alginate (Alg) hydrogel beads incorporating natural bentonite (Bent) clay as a beneficial adsorbent for the removal of toxic methylene blue (MB) from aqueous solution. PVA−Alg/Bent nanocomposite hydrogel beads with different Bent content (0, 10, 20, and 30 wt%) were synthesized via external ionic gelation method. The designed porous and steady structure beads were characterized by the use of Fourier transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDX), and scanning electron microscopy (SEM). The performance of the beads as MB adsorbents was investigated by treating aqueous solutions in batch mode. The experimental results indicated that the incorporation of Bent (30 wt%) in the nanocomposite formulation sustained the porous structure, preserved water uptake, and increased MB removal efficiency by 230% compared to empty beads. Designed beads possessed higher affinity to MB at high pH 8, 30 °C, and fitted well to pseudo-second-order kinetic model with a high correlation coefficient. Moreover, the designed beads had good stability and reusability as they exhibited excellent removal efficiency (90%) after six consecutive adsorption-desorption cycles. The adsorption process was found be combination of both monolayer adsorption on homogeneous surface and multilayer adsorption on heterogeneous surface. The maximum adsorption capacity of the designed beads system as calculated by Langmuir isotherm was found to be 51.34 mg/g, which is in good agreement with the reported clay-related adsorbents. The designed semi-IPN PVA−Alg/Bent nanocomposite hydrogel beads demonstrated good adsorbent properties and could be potentially used for MB removal from polluted water.

scholarly journals Synthesis and Evaluation of the Ability of Poly(Methacrylic Acid-co-acrylamide)/nanoclay Composite Hydrogel in the Adsorption of Methylene Blue Dye

2021 ◽  
Author(s):  
Hamid Safarzadeh ◽  
Seyed Jamaleddin Peighambardoust ◽  
Seyed Hamed Mousavi ◽  
Reza Mohammadi ◽  
Rauf Foroutan ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Adsorption Capacity ◽  
Methacrylic Acid ◽  
Adsorption Process ◽  
Particle Diffusion ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Nanocomposite Hydrogel ◽  
Cloisite 30B ◽  
Intra Particle Diffusion

Abstract The performance of poly(methacrylic acid-co-acrylamide/nanoclay composite (poly(MAA-co-AAm)/NCC) hydrogel to adsorb methylene blue (MB) dye from aqueous solutions was investigated and the adsorption efficiency was improved by incorporating Cloisite 30B nanoclays in the adsorbent structure. The hydrogels were analyzed using FTIR, XRD, TGA, and SEM analysis. The effect of adsorbent dose, temperature, initial dye concentration, contact time, and pH on the efficiency of the adsorption process was investigated. Adsorption efficiencies of 98.57 and 97.65% were obtained for poly(MAA-co-AAm)/NCC and poly(MAA-co-AAm) hydrogels, respectively. Kinetic study revealed that the adsorption process followed pseudo-first-order kinetic model and α-parameter values of 6.558 and 1.113 mg/g.min were obtained for poly(MAA-co-AAm)/NCC and poly(MAA-co-AAm) hydrogels, respectively indicating a higher ability of nanocomposite hydrogel in adsorbing MB-dye. In addition, the results of the intra-particle diffusion model showed that various mechanisms such as intra-particle diffusion and liquid film penetration are important in the adsorption. The Gibbs free energy parameter of adsorption process showed negative values of -256.52 and -84.071 J/mol.K for poly(MAA-co-AAm)/NCC and poly(MAA-co-AAm) hydrogels indicating spontaneous nature of the adsorption. The results of enthalpy and entropy showed that the adsorption process was exothermic and random collisions were reduced during the adsorption. The equilibrium data for the adsorption process using poly(MAA-co-AAm)/NCC and poly(MAA-co-AAm) hydrogels followed Freundlich and Langmuir isotherm models, respectively. The maximum adsorption capacity values of 32.83 and 21.92 mg/g were obtained for poly(MAA-co-AAm)/NCC and poly(MAA-co-AAm) hydrogels, respectively. Higher adsorption capacity of nanocomposite hydrogel was attributed to the presence of Cloisite 30B clay nanoparticles in its structure. In addition, results of RL, n, and E parameters showed that the adsorption process was performed optimally and physically.

scholarly journals Study on the adsorption of methylene blue from aqueous solution using hydrogel glucomannan/graphene oxide

2021 ◽  
Vol 10 (1) ◽  
pp. 59-66
Author(s):  
Son Le Lam ◽  
Phu Nguyen Vinh ◽  
Hieu Le Trung ◽  
Tan Le Thua ◽  
Nhan Dang Thi Thanh ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Graphene Oxide ◽  
Adsorption Capacity ◽  
Organic Dyes ◽  
Dye Adsorption ◽  
Order Kinetic ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Glucomannan/graphene oxide (GM/GO) hydrogel was synthesized by using calcium hydroxide as the crosslinker. The synthesized material was characterized by using IR, XRD, SEM, EDX and RAMAN technology. The composite hydrogel was used for removal of organic dyes from aqueous solution. The results showed that the GM/GO hydrogel had a porous structure and a high adsorption capacity toward methylene blue (MB). The pseudo-second-order kinetic model could fit the rate equation of MB adsorption onto the GM/GO hydrogel. The adsorption of MB onto GM/GO hydrogel was a spontaneous process. In addition, the equilibrium adsorption isotherm data indicated that equilibrium data were fitted to the Langmuir isotherm and the maximum dye adsorption capacity was 198,69 mg.g-1. Moreover, the hydrogel was stable and easily recovered and adsorption capacity was around 97% of the initial saturation adsorption capacity after being used five times.

3D Porous Graphene/Polyvinyl Alcohol Composites: The Effect of Modification on the Adsorption Properties

NANO ◽  
2016 ◽  
Vol 11 (11) ◽  
pp. 1650125 ◽  
Author(s):  
Shuang Sun ◽  
Xiaofei Ma
Keyword(s):  
Polyvinyl Alcohol ◽  
Graphene Nanosheets ◽  
Adsorption Properties ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Porous Structures ◽  
Edta Solution ◽  
Pseudo Second Order

Polyvinyl alcohol (PVA) was grafted on graphene nanosheets (GN) in the reduction of graphene oxide with hydrazine hydrate. The obtained GN-PVA (GP) suspension was treated with the freezing–thawing cycle to fabricate 3D porous monolithic GP materials, which were modified with carbon disulfide to introduce xanthan groups on the wall of porous materials, marked as GPCs. The characterization of GPCs confirmed that PVA was attached on the surface of GNs, and xanthan groups were effectively functionalized on the porous structures, which were composed of randomly oriented GNs. The Pb[Formula: see text] adsorption pattern for GPC materials was investigated. The kinetic adsorption and isotherm data fit the pseudo second-order kinetic and the Langmuir isotherm models, respectively. The maximum adsorption capacity of Pb[Formula: see text] reached 242.7[Formula: see text]mg/g. And GPCs for Pb[Formula: see text] adsorption could be regenerated with ethylenediamine tetracetic acid (EDTA) solution for repetitious adsorption.

Synthesis of Glutaraldehyde-Crosslinked Carboxymethyl Cellulose-Polyvinyl Alcohol Film as an Adsorbent for Methylene Blue

2020 ◽  
Vol 840 ◽  
pp. 35-42
Author(s):  
Dwi Siswanta ◽  
Rizky Wahyuni ◽  
Mudasir Mudasir
Keyword(s):  
Methylene Blue ◽  
Polyvinyl Alcohol ◽  
Carboxymethyl Cellulose ◽  
Contact Time ◽  
Order Kinetic ◽  
Casting Technique ◽  
Sem Image ◽  
Ftir Characterization ◽  
Desorption Study ◽  
Polyvinyl Alcohol Film

The glutaraldehyde (GA)-crosslinked carboxymethyl cellulose (CMC)-polyvinyl alcohol (PVA) film had been synthesized and used as a methylene blue adsorbent. The films were prepared using a solution casting technique and characterized using FTIR spectrophotometer, SEM. Adsorption studies include pH, contact time, methylene blue initial concentration. Furthermore, the desorption study of films was carried out using NaCl, HCl and distilled water. The results of FTIR characterization showed similarities between the spectra of CMC-PVA-GA films with their component materials. The SEM image of CMC-PVA-GA films showed a non-porous surface. In the adsorption study, GA-crosslinked CMC-PVA films (1:2 w/w) exhibited the largest adsorption capacity of methylene blue at optimum conditions for adsorption at pH 7, contact time 200 min, methylene blue concentration of 200 mg L–1 which was 194 mg g–1. Methylene blue adsorption kinetic followed the pseudo second-order kinetic model and the Langmuir adsorption isotherm model. The desorption studies show that adsorption takes place through an ion exchange mechanism.

Chlorate Removal by Calcined Mg/Fe/Ce Layered Double Hydroxides

2015 ◽  
Vol 737 ◽  
pp. 537-540
Author(s):  
Yan Wei Guo ◽  
Hua Zhang ◽  
Zhi Liang Zhu
Keyword(s):  
Polluted Water ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Solution Ph ◽  
Langmuir Adsorption ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Double Hydroxide ◽  
Double Hydroxides ◽  
Kinetics Of

A novel Mg/Fe/Ce layered double hydroxide (LDHs) and its calcined product (CLDH) were synthesized and CLDH was used as adsorbents for the removal of chlorate ions. Results showed that the initial solution pH was an important factor influencing the chlorate adsorption. The adsorption behavior of chlorate followed the Langmuir adsorption isotherm with a maximum adsorption capacity of 18.2 mg/g. The adsorption kinetics of chlorate on CLDH can be described by the pseudo-second-order kinetic model. It was concluded that the CLDH material is a potential adsorbent for the purification of polluted water with chlorate.

scholarly journals Core-Shell Structured Magnetic Carboxymethyl Cellulose-Based Hydrogel Nanosorbents for Effective Adsorption of Methylene Blue from Aqueous Solution

Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3054
Author(s):  
Yiming Zhou ◽  
Te Li ◽  
Juanli Shen ◽  
Yu Meng ◽  
Shuhua Tong ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Carboxymethyl Cellulose ◽  
Chemical Properties ◽  
Polymer Nanocomposite ◽  
Core Shell ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Solution Ph

This article reports effective removal of methylene blue (MB) dyes from aqueous solutions using a novel magnetic polymer nanocomposite. The core-shell structured nanosorbents was fabricated via coating Fe3O4 nanoparticles with a layer of hydrogel material, that synthesized by carboxymethyl cellulose cross-linked with poly(acrylic acid-co-acrylamide). Some physico-chemical properties of the nanosorbents were characterized by various testing methods. The nanosorbent could be easily separated from aqueous solutions by an external magnetic field and the mass fraction of outer hydrogel shell was 20.3 wt%. The adsorption performance was investigated as the effects of solution pH, adsorbent content, initial dye concentration, and contact time. The maximum adsorption capacity was obtained at neutral pH of 7 with a sorbent dose of 1.5 g L−1. The experimental data of MB adsorption were fit to Langmuir isotherm model and Pseudo-second-order kinetic model with maximum adsorption of 34.3 mg g−1. XPS technique was applied to study the mechanism of adsorption, electrostatic attraction and physically adsorption may control the adsorption behavior of the composite nanosorbents. In addition, a good reusability of 83.5% MB recovering with adsorption capacity decreasing by 16.5% over five cycles of sorption/desorption was observed.

scholarly journals Synthesis of Porous Material from Coal Gasification Fine Slag Residual Carbon and Its Application in Removal of Methylene Blue

Molecules ◽  
2021 ◽  
Vol 26 (20) ◽  
pp. 6116
Author(s):  
Yixin Zhang ◽  
Rumeng Wang ◽  
Guofeng Qiu ◽  
Wenke Jia ◽  
Yang Guo ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Kinetic Model ◽  
Porous Material ◽  
Coal Gasification ◽  
Raw Material ◽  
Maximum Adsorption Capacity ◽  
Residual Carbon ◽  
Order Kinetic ◽  
Activation Temperature ◽  
Foam Flotation

A large amount of coal gasification slag is produced every year in China. However, most of the current disposal is into landfills, which causes serious harm to the environment. In this research, coal gasification fine slag residual carbon porous material (GFSA) was prepared using gasification fine slag foam flotation obtained carbon residue (GFSF) as raw material and an adsorbent to carry out an adsorption test on waste liquid containing methylene blue (MB). The effects of activation parameters (GFSF/KOH ratio mass ratio, activation temperature, and activation time) on the cation exchange capacity (CEC) of GFSA were investigated. The total specific surface area and pore volume of GSFA with the highest CEC were 574.02 m2/g and 0.467 cm3/g, respectively. The degree of pore formation had an important effect on CEC. The maximum adsorption capacity of GFSA on MB was 19.18 mg/g in the MB adsorption test. The effects of pH, adsorption time, amount of adsorbent, and initial MB concentration on adsorption efficiency were studied. Langmuir isotherm and quasi second-order kinetic model have a good fitting effect on the adsorption isotherm and kinetic model of MB.

scholarly journals Sheet-like Skeleton Carbon Derived from Shaddock Peels with Hierarchically Porous Structures for Ultra-Fast Removal of Methylene Blue

Water ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 2554
Author(s):  
Panlong Dong ◽  
Hailin Liu ◽  
Shengrui Xu ◽  
Changpo Chen ◽  
Suling Feng ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Adsorption Process ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Initial Concentration ◽  
Hierarchically Porous ◽  
Column Adsorption

To remove the pollutant methylene blue (MB) from water, a sheet-like skeleton carbon derived from shaddock peels (SPACs) was prepared by NaOH activation followed by a calcination procedure under nitrogen protection in this study. Characterization results demonstrated that the as-prepared SPACs displayed a hierarchically porous structure assembled with a thin sheet-like carbon layer, and the surface area of SPAC-8 (activated by 8 g NaOH) was up to 782.2 m2/g. The as-prepared carbon material presented an ultra-fast and efficient adsorption capacity towards MB due to its macro-mesoporous structure, high surface area, and abundant functional groups. SPAC-8 showed ultrafast and efficient removal capacity for MB dye. Adsorption equilibrium was reached within 1 min with a removal efficiency of 99.6% at an initial concentration of 100 mg/g under batch adsorption model conditions. The maximum adsorption capacity for MB was up to 432.5 mg/g. A pseudo-second-order kinetic model and a Langmuir isotherm model described the adsorption process well, which suggested that adsorption rate depended on chemisorption and the adsorption process was controlled by a monolayer adsorption, respectively. Furthermore, column adsorption experiments showed that 96.58% of MB was removed after passing through a SPAC-8 packed column with a flow rate of 20 mL/min, initial concentration of 50 mg/L, and adsorbent dosage of 5 mg. The as-prepared adsorbent displays potential value in practical applications for dye removal due to its ultrafast and efficient adsorption capacity.

scholarly journals PREPARATION OF TEMPO-CELLULOSE NANOFIBER/ZINC OXIDE AS ANTIMICROBIAL AND METHYLENE BLUE PHOTO-DEGRADING NANOCOMPOSITE

2021 ◽  
Vol 55 (3-4) ◽  
pp. 365-373
Author(s):  
MOHAMED EL-SAKHAWY ◽  
AHMED SALAMA ◽  
AHMED K. EL-ZIATY ◽  
HAZEM HASSAN
Keyword(s):  
Methylene Blue ◽  
Zinc Oxide ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Environmental Remediation ◽  
Organic Dyes ◽  
Cellulose Nanofibers ◽  
Light Irradiation ◽  
Order Kinetic ◽  
Catalytic Material

"Photo-catalytic degradation of organic dyes in aquatic environments under visible light irradiation affords an efficient and economic technique for environmental remediation. TEMPO-oxidized cellulose nanofibers/zinc oxide nanocomposite (TEMPO-CNF/ZnO) was prepared through oxidation of cellulose pulp, followed by zinc oxide precipitation in the presence of oxidized fibers. TEMPO-CNF/ZnO was characterized by different techniques. The degradation rate of methylene blue (MB) by TEMPO-CNF/ZnO was gradually increased with increasing pH and the degradation reached 86% within 340 minutes at pH 7. The kinetic study showed that the pseudo-first-order kinetic best fitted the photo-catalytic process. A mechanism was proposed for the degradation of MB using TEMPO-CNF/ZnO under visible light irradiation. TEMPO-CNF/ZnO showed high antibacterial activity against S. aureus and E. coli. Thus, the TEMPO-CNF/ZnO nanocomposite has been demonstrated to be an effective photo-catalytic material for degrading MB under visible light irradiation."

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