Efficient removal of Cr(VI) from aqueous solutions using chitosan/Na‐alginate bio‐based nanocomposite hydrogel

Abstract

This research article aimed to assist the works conducted to save water resources, which are rapidly depleted as a result of climate change by eliminating toxic chromium ions Cr(VI) from simulated solution. In this regard, chitosan/Na‐alginate/polyacrylic acid (CS/Na‐Alg/PAAc) and Ni/chitosan/Na‐alginate/polyacrylic acid (Ni@CS/Na‐Alg/PAAc) were created as eco‐friendly hydrogel composites via gamma radiation. The hydrogel matrix served as a basin for the in‐situ formation of Ni nanoparticles. The prepared composites were characterized by the FTIR and XRD analyses. The surface morphology of the nanocomposite was also verified via the SEM. It exhibited a dense packing of the Ni nanoparticles representing about 2.5% of the atomic percentage depicted by the EDX analysis. The swelling performance was investigated versus different pH values and the maximum swelling percent was attained as a non‐Fickian character at pH = 13 and 5 for CS/Na‐Alg/PAAc and Ni@CS/Na‐Alg/PAAc, respectively. Furthermore, the surface topographies of CS/Na‐Alg/PAAc and Ni@CS/Na‐Alg/PAAc loaded with Cr(VI) were examined by AFM at different pH values. The maximum Cr(VI) removal was top achieved at pH 8 (58.06 and 74.5 mg/g for CS/Na‐Alg/PAAc and Ni@CS/Na‐Alg/PAAc, respectively) and best fit with the Freundlich isotherm model with calculated RL values indicated a favorable adsorption.

Optimization, Kinetics, and Isotherm Studies of Methyl Thioninium Chloride Removal from Simulated Solutions Using Chitosan Derivatives

“…Upon studying the topographies of the dry sorbents, one can detect some striations and convolutions in the AFM images of the cross-linked candidates which confirm the creation of network structure. This protocol fits our previous works 20,21 for employing the AFM in monitoring the adsorption process. Moreover, the roughness measurements of dye-free and dye-loaded sorbents were provided (as calculated from Flexaxiom software).…”

“…Chitosan is an abundant supply of amino and hydroxyl groups that can use electrostatic and hydrogen bonding to absorb dyes and heavy metal ions. 20,21 It is the second most abundant renewable natural resource after cellulose. 22 On the other hand, chitosan possesses some drawbacks, which restrict its application in neat form such as weak mechanical qualities, a limited specific surface area, and ease of acid dissolution.…”

“…Adsorption has been the method of choice for the treatment of dyeing wastewater because of its simplicity, high efficacy, wide applicability, cheap operating costs, and environmental friendliness. – Due to its ease of chemical modification and chemical stability, chitosan is a typical representative of biomass-based absorbents. Chitosan is an abundant supply of amino and hydroxyl groups that can use electrostatic and hydrogen bonding to absorb dyes and heavy metal ions. , It is the second most abundant renewable natural resource after cellulose . On the other hand, chitosan possesses some drawbacks, which restrict its application in neat form such as weak mechanical qualities, a limited specific surface area, and ease of acid dissolution. , It can be typically altered through procedures including cross-linking, grafting, the addition of magnetic species, and nanoparticles, by chemical protocols, and gamma irradiation before being widely employed in a range of wastewater treatment treatments.…”

Development of a Novel Elastomer with unique properties: Fire and Radiation resistance

“…The asymmetric stretching vibrations of C-H appears at 2931 cm − 1 [28, 29], which con rmed by the bending vibration band at 1042 cm − 1.The band at 1735 cm − 1 due to C = O stretching vibrations [30].The splitting pattern of C = O may be related to the in uence of hydrogen bonds. The band at 1138 cm − 1 is caused by C-O stretching vibrations in ether linkages between aromatic rings in lignin.…”