Figure - available from: ChemistrySelect
This content is subject to copyright. Terms and conditions apply.
(a–e) Adsorption isotherm of BG and CV (a) Freundlich (b) Langmuir (c) Temkin (d) Elovich and (e) Dubinin‐Radushkevich (f) Thermodynamic plot of adsorption of BG and CV dyes on GG/epi/CMC hydrogel.
Source publication
This study reports the microwave synthesis of Guar gum (GG) and Carboxymethyl cellulose (CMC) based hydrogel covalently crosslinked using epichlorohydrin (epi), aiming to remove hazardous dyes like Crystal Violet (CV) and Brilliant Green (BG). The optimized parameters were the reaction time (40 s), solvent (12 ml), pH (11), the ratio of reactants (...
Citations
Ensuring the availability of water resources that are both clean and safe is crucial for the preservation of environmental health and the well‐being of humans. Here, we fabricated carboxymethyl cellulose‐based hydrogel nanocomposite using acrylic acid (AA) and 2‐acrylamido‐2‐methylpropane sulfuric acid (AMPS) monomers and Fe3O4 nanoparticles through a free radical crosslinking process for adsorption of dyes from contaminated water. The synthesized nanocomposite hydrogel was characterized using various techniques, including TEM, XRD, FTIR, SEM‐EDS, TGA, and AFM analysis. The swelling capacity of samples in an aqueous medium at multiple pH levels and the presence of different salts were investigated. The adsorption efficiency of methylene blue (MB) and crystal violet (CV), emphasizing the effect of hydrogel concentration and the medium's pH, was studied. It was concluded that the hydrogel sample containing 17 % AMPS and 51 % AA had better swelling capacity and dye removal efficiency. The dye adsorption kinetics data were fitted to pseudo‐first and second‐order kinetic models and the Langmuir and Temkin isotherm models. The maximum adsorption capacity for MB and CV was 53.97 and 53.57 mg/g, respectively. It was revealed that the pseudo‐second‐order kinetic model could best describe adsorption (qe=79.2 mg/g for MB and qe=65.8 mg/g for CV). The intra‐particle diffusion model was found to be the rate‐limiting mechanism of dye adsorption. Thermodynamic studies proposed that the adsorption of MB and CV was spontaneous and endothermic. Additionally, magnetic nanocomposite hydrogel‘s reusability up to four successive cycles further determines its probability of adsorption of dyes from wastewater.
In this study, p(CTP‐co‐MMCA) microparticles, a novel cyclomatrix polyphosphazene, were synthesized. Among the p(CTP‐co‐MMCA) polymeric structures, p(CTP‐co‐MMCA) (1 : 3) with a high surface amine group was found to be in the form of microparticles after detailed structural and morphological characterization. These microparticles were modified with Au⁰ and Ag⁰ nanoparticles using two different green reductants. The antimicrobial activities of p(CTP‐co‐MMCA) microparticles and their Au⁰ and Ag⁰ composites against P.Aeruginosa ATCC 27853, S.Aureus ATCC 6538 and C.Albicans were investigated. Metal composites were found to have better antimicrobial activity. Cyclomatrix p(CTP‐co‐MMCA) microparticles with antimicrobial properties and their Au⁰ and Ag⁰ composites were also used for the release of Ceftriaxone sodium and RNA. Cyclomatrix p(CTP‐co‐MMCA) microparticles and its Au⁰ and Ag⁰ composites retained 48.21±5.34 mg/g, 49.36±6.95 mg/g and 23.95±6.45 mg/g ceftriaxone sodium, respectively, while they retained 79.15±6.85 mg/g, 47.49±6.24 mg/g and 57.47±9.48 mg/g RNA, respectively. Release studies revealed that the presence of Au⁰ and Ag⁰ nanoparticles imparted a slower release behavior to p(CTP‐co‐MMCA) microparticles. The release studies revealed that the presence of Au⁰ and Ag⁰ nanoparticles imparted a slower release behavior to the p(CTP‐co‐MMCA) microparticles.
Herein, a novel environmentally friendly benzenesulfonyl hydrazone modified guar gum (DGH) that carries excellent adsorption performance towards dyes was facilely prepared through oxidation and condensation. The structure, morphology, and physics-chemical of DGH were fully characterized by multiple analysis techniques. The as-prepared adsorbent yielded highly efficient separating performance towards multiple anionic and cation dyes, including CR, MG, and ST with the maximum adsorption capacity of 1065.3839 ± 10.5695, 1256.4467 ± 2.9425, and 1043.8140 ± 0.9789 mg/g at 298.15 K, respectively. The adsorption process well fitted the Langmuir isotherm models and the pseudo-second-order kinetic models. The adsorption thermodynamics revealed that the adsorption of dyes onto DGH was spontaneous and endothermic. The adsorption mechanism indicated that the hydrogen bonding and electrostatic interaction participated in the fast and efficient removal of dyes. Furthermore, the removal efficiency of DGH still remained above 90 % after six adsorption-desorption cycles, and the presence of Na+, Ca2+, and Mg2+ have weakly impacted the removal efficiency of DGH. The phytotoxicity assay was conducted via the germination of mung bean seeds, which confirmed the adsorbent can effectivity decreased the toxicity of dyes. Overall, the modified gum-based multifunctional material has good promising applications for wastewater treatment.
