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1.
Sci Rep ; 14(1): 9102, 2024 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-38643156

RESUMO

In this study, a Sodium alginate-g-poly (acrylamide-clay)/TiO2 hydrogel nanocomposite [SA-g-p(AM-Bn)/TiO2] was synthesized using the biopolymer sodium alginate (SA), acrylamide (AM), and bentonite clay (Bn) as hybrid materials embedded with titanium dioxide nanoparticles (TiO2NPs) for the removal of toxic Congo Red (CR) dye from an aqueous solution. The [SA-g-p(AM-Bn)/TiO2] nanocomposite has been described on the basis of thermal stability, morphological analysis, estimation of functional group, and crystalline/amorphous character by TGA, EFSEM/EDX, TEM, FT-IR, and XRD analysis, respectively. The effects of operational parameters toward the CR dye adsorption on [SA-g-p(AM-Bn)/TiO2], including contact time, adsorbent dosage, initial concentration, initial pH, and temperature were investigated. The maximum adsorption efficiency was found to be 185.12 mg/g for [SA-g-p(AM-Bn)/TiO2] in 100 mg/L of solution CR at pH 6.0 within 1 h. The equilibrium isotherms, kinetics, and thermodynamics parameters of adsorption were examined, and results showed that the isotherm fitted the Freundlich model and the kinetics adsorption model of CR followed pseudo-first-order, thus indicating physisorption of anionic-CR onto the sorbent due to the development of an electrostatic attraction bond. Thermodynamic parameters for [SA-g-p(AM-Bn)/TiO2] have values (ΔG and ΔH) reflecting the spontaneous and endothermic nature of the adsorption processes. Moreover, [SA-g-p(AM-Bn)/TiO2] presented outstanding excellent reusability and recyclability with a relatively best removal percentage as compared to [SA-g-p(AM-Bn)] and suggested their applicability towards the textile industry and water purification purposes.

2.
Ultrason Sonochem ; 97: 106463, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37290151

RESUMO

Water pollution management, reduction, and elimination are critical challenges of the current era that threaten millions of lives. By spreading the coronavirus in December 2019, the use of antibiotics, such as azithromycin increased. This drug was not metabolized, and entered the surface waters. ZIF-8/Zeolit composite was made by the sonochemical method. Furthermore, the effect of pH, the regeneration of adsorbents, kinetics, isotherms, and thermodynamics were attended. The adsorption capacity of zeolite, ZIF-8, and the composite ZIF-8/Zeolite were 22.37, 235.3, and 131 mg/g, respectively. The adsorbent reaches the equilibrium in 60 min, and at pH = 8. The adsorption process was spontaneous, endothermic associated with increased entropy. The results of the experiment were analyzed using Langmuir isotherms and pseudo-second order kinetic models with a R2 of 0.99, and successfully removing the composite by 85% in 10 cycles. It indicated that the maximum amount of drug could be removed with a small amount of composite.


Assuntos
Poluentes Químicos da Água , Zeolitas , Azitromicina , Zeolitas/química , Poluentes Químicos da Água/química , Termodinâmica , Cinética , Adsorção , Água , Preparações Farmacêuticas , Concentração de Íons de Hidrogênio
3.
Ultrason Sonochem ; 95: 106362, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36907102

RESUMO

Thulium vanadate (TmVO4) nanorods were successfully prepared by a simple sonochemical approach using Schiff-base ligands. Additionally, TmVO4 nanorods were employed as a photocatalyst. The most optimal crystal structure and morphology of TmVO4 have been determined and optimized by varying Schiff-base ligands, the molar ratio of H2Salen, the sonication time and power, and the calcination time. A Eriochrome Black T (EBT) analysis revealed that the specific surface area was 24.91 m2/g. A bandgap of 2.3 eV was determined by diffuse reflectance spectroscopy (DRS) spectroscopy, which makes this compound suitable for visible photocatalytic applications. In order to assess the photocatalytic performance under visible light, two anionic dyes (EBT) and cationic dyes (Methyl Violet (MV)) were used as models. A variety of factors have been studied in order to improve the efficiency of the photocatalytic reaction, including dye type, pH, dye concentration, and catalyst loading. Under visible light, the highest efficiency was achieved (97.7%) when 45 mg TmVO4 nanocatalysts were present in 10 ppm Eriochorome Black T at pH = 10.

4.
Environ Technol ; 38(17): 2119-2129, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27884094

RESUMO

ZnO nanoparticles of rod-like architecture have excellent potential to be used in wastewater treatment as a photocatalyst. They were synthesized by utilizing sonochemical/hydration- dehydration techniques using glutamine as a biotemplate. The effects of calcination temperatures, that is, 300°C, 500°C, and 700°C, on the crystallinity, optical properties, and photocatalytic activity of synthesized zinc oxide nanoparticles were investigated. X-ray diffraction (XRD) results indicated that all calcinated samples have a crystalline hexagonal wurtzite structure. Morphology and elemental compositions were investigated using field emission-scanning electron microscopy with energy-dispersive X-ray spectroscopy. The XRD and Fourier transform infrared (FTIR) spectra revealed that the samples were amorphous at 100°C; however, it changed into a crystalline structure amid the calcination process. Optical properties were determined using a UV-visible reflection spectrophotometer and showed abatement in the band gap with increasing annealing temperature. The progress of the photocatalytic degradation was monitored by a UV-visible spectrophotometer, while the mineralization ability was estimated by total organic carbon tests of ZnO-calcinated samples. The effect of various operational parameters the photocatalytic efficiency and rate of dye degradation was studied. High photocatalytic degradation of maxilon blue dye (GRL) was found at pH 6.3.


Assuntos
Nanopartículas Metálicas/química , Óxido de Zinco/química , Catálise , Desidratação , Nanopartículas , Difração de Raios X
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