30 research outputs found
Exploitation of expired cellulose biopolymers as hydrochars for capturing emerging contaminants from water
No full textPolymer/Activated Charcoal-Coated Magnetite for the Adsorptive Removal of Emerging Contaminants: Stepwise Synthesis via Two Sequential Routes
No full textEmerging contaminants pose great health risks to humans and living organisms, even when released at minute concentrations over prolonged exposure times. In this work, we fabricate nanocomposites based on activated charcoal-coated magnetite by incorporating the biopolymers of xylan or pectin into their structure. Two synthesis routes which differ in their sequential steps were investigated. It was demonstrated that the synthesis route affects the morphology, textural properties, and chemical structure of the nanocomposites, as confirmed by Scanning Electron Microscopy (SEM), Brunauer-Emmett-Teller (BET) analysis, and Fourier Transform Infra-red (FTIR) measurements, respectively. Hence, in turn, it influences the performance of the nanocomposites in their adsorptive removal for the emerging contaminants of Fluoxetine and Famotidine, whose presence in wastewater have been confirmed in several studies
Multifunctional Chitosan/Xylan-Coated Magnetite Nanoparticles for the Simultaneous Adsorption of the Emerging Contaminants Pb(II), Salicylic Acid, and Congo Red Dye
No full textIn this work, we develop chitosan/xylan-coated magnetite (CsXM) nanoparticles as eco-friendly efficient adsorbents for the facile removal of contaminants from water. Characterization of CsXM using Fourier Transform Infra-Red (FTIR) Spectroscopy, Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), Thermogravimetric Analysis (TGA), Transmission Electron Microscopy (TEM), Zeta potential measurements, and Brunauer-Emmet-Teller (BET) analysis, confirmed the successful preparation of a chitosan/xylan complex coated over magnetite, which is characterized by being mesoporous, thermally stable and of neutral charge. Three contaminants, Pb(II), salicylic acid (SA), and congo red (CR), were chosen as representative pollutants from three major classes of contaminants of emerging concern: heavy metals, pharmaceuticals, and azo dyes. Pb(II), SA, and CR at initial concentrations of 50 ppm were removed by 64.49, 62.90, and 70.35%, respectively, on applying 6 g/L of CsXM. The contaminants were successfully removed in ternary systems, with Pb (II) and SA being more competitive in their adsorption than CR. Adsorption followed the Freundlich isotherm model and the pseudo-second order kinetic model, while the binding was suggested to occur mainly via chemical chelation for Pb(II) and physical interaction for SA and CR, which demonstrates the multifunctional potential of the nanoparticles to capture different contaminants regardless of their charge
Synthesis of Doped Sol-Gel Glasses as Adsorbents for Water Treatment
No full textDoped sol-gel glasses of thiourea (THU), urea (U), n-propoylamine (PA), iso-propylamine (IPA), and 2-methoxyaniline (AN) were prepared and treated by two methods, thermal and microwave (MW) irradiation. The optical properties and particle sizes of the as-synthesized doped sol-gels and plain sol-gel (P) were measured. The sol-gels were then tested for their capacity to adsorb methylene blue dye (MB) and remove it from aqueous solutions. The highest removal efficiencies were exhibited by PA, IPA, and THU which were prepared by either the thermal or MW method. Amongst all the tested adsorbents, the thermally-prepared PA yielded the highest removal of over 95% for 12.5 mg/L of MB, and about 75% for 6.5 mg/L of MB. The MW-prepared PA showed the second highest removal efficiencies, while IPA, prepared thermally or by MW, showed comparable results to its PA counterpart. This behavior could be attributed to the higher basicity of aliphatic amines relative to aromatic amines, which resulted in increased interaction between the lone pair of electrons on amino nitrogen and MB. On the other hand, the interaction between U or THU and MB is suggested to have possibly occurred via electrostatic attraction or redox reaction between them. The characteristic Fourier Infrared (FTIR) spectra of PA and IPA before and after adsorption suggest that the C=O, N-H, and Si-OH groups, among others, could be involved in adsorption
Confocal microscopy study of uptake kinetics of α‐lactalbumin and β‐lactoglobulin onto the cation‐exchanger SP Sepharose FF
No full textPurification of the two major proteins from whey concentrate using a cation‐exchange selective adsorption process
No full textA quantitative approach for studying the bioactivity of nano-hydroxyapatite composites
No full textInternational audienceThis work describes a quantitative kinetic approach to assess the in-vitro bioactivity of gold-doped hydroxyapatite-polyvinyl alcohol nanocomposites. The surface morphology of the in-situ prepared nanocomposites as characterized by Transmission Electron Microscopy (TEM) revealed a rod-like shape. Differential Thermal Analysis-Thermogravimetric (DTA-TG) and Fourier Transformed Infrared Spectroscopy (FT-IR) as well as zeta potential measurements of the prepared nanocomposites were carried out. Uptake profiles of Ca and P were studied onto nanocomposites of different gold concentrations after their soaking in simulated body fluid (SBF) and they best followed the pseudo second-order kinetic model. The highest uptakes of both Ca and P were obtained using the nanocomposite with the lowest concentration of gold. Furthermore, sorption mechanism was described by the intra-particle diffusion model where pore diffusion was found to be the rate limiting step. The prepared nanocomposites have promising potential in orthopaedic and tissue engineering applications due to their high capacity and fast uptake for Ca and P which form apatite. This article is protected by copyright. All rights reserved.[on SciFinder (R)
Efficient drug delivery vehicles of environmentally benign nano-fibers comprising bioactive glass/chitosan/polyvinyl alcohol composites
No full textNano-fiber composites have shown promising potential in biomedical and biotechnological applications. Herein, novel nano-fiber composites constituting a blend of polyvinyl alcohol (PVA) and chitosan (CS) along with different weight ratios of nano-bioactive glass (BG) were prepared by electrospinning. Nano-fibers incorporating 10% (by wt.) of BG were uniform, dense and defect-free with a diameter of 20-125 nm. The model osteoporotic drug (Risedronate sodium) was blended with the electrospinning forming solution and the in-vitro drug release was further studied. About 30% of the drug was released after only 30 min and the release pattern was sustained over 96 h. Drug release took place through a two-stage intra-particle diffusion mechanism. BG-incorporated nano-fibers markedly retarded the drug release profile relative to their BG-free counterparts. They also enhanced the drug release efficiency by releasing 93 ± 4% of the drug. The developed nano-fiber composites can be potentially used as drug-delivery vehicles due to their efficiency and sustained drug release capacity
