Cross-linking and modification of sodium alginate biopolymer for dye removal in aqueous solution

Merakchi, Akila; Bettayeb, Souhila; Drouiche, Nadjib; Adour, Lydia; Lounici, H.

doi:10.1007/s00289-018-2557-x

Cited by 41 publications

(19 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Alginate acid as a natural polysaccharide extracted from brown algae possesses many advantages compared to the various polymers adopted for elaborating hydrogel micro and nanobeads [12,[23][24][25][26][27][28][29]. The alginate macromolecule consists of chains of gluconic acid (G-block) and chains of mannuronic acid (M-block) and chains of mixed sequence of M-G-blocks.…”

Section: Introductionmentioning

confidence: 99%

Optimization of gallic acid encapsulation in calcium alginate microbeads using Box-Behnken Experimental Design

et al. 2020

View full text Add to dashboard Cite

The aim of this study was the optimization of the gallic acid (GA) encapsulation efficiency within calcium alginate microparticles by the ionotropic gelation technique, using Box-Behnken design for the surface methodology response. For this purpose, three independent variables were selected: sodium alginate concentration (X1), calcium chloride concentration (X2), and gallic acid concentrations (X3). The influence of each variable on the encapsulation efficiency was evaluated. The optimum conditions to reach maximum encapsulation efficiency were found to be: X1 = 30 g/l (3%, w/v), X2 = 21.63 g/l (2.163%, w/v) and X3 = 15 g/l (1.5%, w/v), respectively. The encapsulation efficiency was determined to be 42.8%. The obtained microbeads were further examined using differential scanning calorimetry (DSC) and Fourier transform infrared (ATR-FTIR), and the inclusion of gallic acid was confirmed. The gallic acid concentration (X3) is the statistically significant factor in the optimization process. In addition, no autoxidation of the gallic acid compound was observed in the formulated calcium alginate microbeads. Scanning electron microscope (SEM) analysis showed that the shape of the particle was spherical for all formulations and their surface is wrinkled. The release study of the gallic acid carried out in an aqueous medium at pH value 6.8, showed that the GA release pattern was fast for all systems studied (85% at 20 min), and the profile of the release was influenced by the size of the calcium alginate microbeads. The obtained results reveal that the calcium alginate microbeads prepared through the ionotropic gelation technique possess great prominent for gallic acid encapsulation as well as its liberation.

show abstract

Section: Introductionmentioning

confidence: 99%

Optimization of gallic acid encapsulation in calcium alginate microbeads using Box-Behnken Experimental Design

et al. 2020

View full text Add to dashboard Cite

show abstract

“…However, during air drying, the initial spherical shape of the beads was slightly changed, resulting in rough surface morphology without a marked collapse on the surface, indicating an improved mechanical stability (Figure 2b). Indeed, the deformation in shape is inevitable when water was evaporated from the wet hydrogel beads throughout the drying process, causing volume shrinkage of hydrogel beads [52]. Figure 2c reveals black color of the beads indicated encapsulation of MB in the nanocomposite hydrogel beads.…”

Section: Fabrication Of Nanocomposite Hydrogel Beadsmentioning

confidence: 99%

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

Aljar¹,

Rashdan²,

El-Fattah³

2021

Preprint

View full text Add to dashboard Cite

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.

show abstract

“…Beside generating limited pore size range around a nanometer, the graphene interlayer spacing is susceptible to collapse if the metal ions leach out with a change in solution conditions. [ 16 ] Natural polymers (e.g., gelatin, [ 17 ] chitin, [ 18 ] cellulose, [ 19 ] pectin, [ 20 ] carrageenan, [ 21 ] starch, [ 22 ] and alginate [ 23 ] ) have also been known as effective materials for dye adsorption because they are nontoxic, biodegradable, inexpensive, and contain many functional groups on their structure. Polymeric hydrogels have been shown to be interesting in dye adsorption since the porous structure of hydrogels let the dye solution to diffuse rapidly into the polymeric network and interact with its functional groups.…”

Section: Introductionmentioning

confidence: 99%

Self‐Assembled Graphene Hydrogel Composites for Selective Dye Removal

Subhi

Kiamahalleh

Firouzi

et al. 2020

Advanced Sustainable Systems

View full text Add to dashboard Cite

Graphene‐based hydrogels are known as promising amphiphilic agents for water uptake and selective organic contaminant removal. However, it is a challenge to prevent graphene sheet restacking during the gelation as this factor significantly influences the adsorption behavior of organic contaminant. A porous reduced graphene oxide‐starch hydrogel (rGOSH) with enhanced pore size is produced by a simple one‐step method through starch‐directed self‐assembly of graphene sheets. This hydrogel demonstrated to be a promising candidate for the selective removal of organic dye molecules, where positive and neutral dyes are adsorbed, and the negative one is repelled. In particular, the hydrogel prepared with incorporation of starch between the graphene sheets, adsorbs positively charged dye ≈75% more than reduced graphene oxide hydrogel, due to better diffusion into larger pore size and strong electrostatic interaction with negatively charged oxygen groups. Furthermore, the Langmuir isotherm model and kinetic studies for dyes adsorption onto rGOSH reveal that the adsorption mechanisms are dominantly chemisorption within the porous hydrogel structure since the experimental data can be well fitted to the pseudo‐second‐order dynamic equation with the highest adsorption capacity (1106.950 µg g−1) and kinetic (1.957E‐05 g µg−1 min−0.5) toward the positively charged dye.

show abstract

Cross-linking and modification of sodium alginate biopolymer for dye removal in aqueous solution

Cited by 41 publications

References 40 publications

Optimization of gallic acid encapsulation in calcium alginate microbeads using Box-Behnken Experimental Design

Optimization of gallic acid encapsulation in calcium alginate microbeads using Box-Behnken Experimental Design

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

Self‐Assembled Graphene Hydrogel Composites for Selective Dye Removal

Contact Info

Product

Resources

About