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1.
Environ Sci Pollut Res Int ; 31(10): 14662-14689, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38280170

RESUMO

Agricultural wastes are potential sustainable adsorbents since they are available in large quantities, are low-cost, and may require little or no treatment, in some cases. In this study, several fruit peels, such as banana, orange, and pomegranate, were collected from local markets and prepared by a simple and eco-friendly method and used as natural adsorbents for the removal of both anionic (Reactive Red 120 (RR120), Reactive Black 5 (RB5), Remazol Brilliant Blue R (RBBR)) and cationic Methylene Blue (MB) dyes found in wastewaters. Many industries, such as leather and textiles, can release huge amounts of synthetic dyes into the wastewater during dyeing processes. These are one of the most important pollutants of water pollution as they cause enormous damage to the water body and also affect the health of organisms due to their toxicity and carcinogenicity. The search for a sustainable and at the same time efficient material for the removal of a wide variety of dyes is the innovation of this work. These peels were prepared by washing, drying, grinding, and finally sieving, under natural sustainable conditions. Porosometry (BET analysis), FTIR, SEM/EDS, and XRD techniques were used to characterize the fruit peels before and after the adsorption process. Factors affecting the adsorption of dyes (adsorbent dosage, pH solution, initial concentration of dyes, contact time, and temperature) were investigated. According to the results, in terms of the effectiveness of fruit peels as (natural) adsorbent materials, for anionic dyes, 5.0-6.0 g/L of banana or orange dry peels was sufficient to remove near or even more than 90% anionic dyes at pH 2.0, and 4.0 g/L was sufficient to remove 98% of cationic MB dye at pH 9.0. Similar amount of pomegranate peels had lower efficiency for anionic dyes (50-70%), while cationic MB was still efficiently removed (98%) at pH 9.0. Moreover, the adsorption process in all cases was found to better fit to pseudo-second-order model, in comparison to pseudo-first-order model. According to isotherms, Freundlich model fitted better in some cases to the equilibrium data, while the Langmuir model in others. Finally, this study demonstrates the viability of reusing the banana, orange, and pomegranate peel adsorbents for eight, four, and five cycles, showing a gradual reduction of around 50% of their effectiveness.


Assuntos
Citrus sinensis , Musa , Poluentes Químicos da Água , Águas Residuárias , Corantes/química , Frutas/química , Poluentes Químicos da Água/análise , Cinética , Adsorção , Azul de Metileno/química , Concentração de Íons de Hidrogênio
2.
Int J Mol Sci ; 23(22)2022 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-36430357

RESUMO

The massive accumulation of plastics over the decades in the aquatic environment has led to the dispersion of plastic components in aquatic ecosystems, invading the food webs. Plastics fragmented into microplastics can be bioaccumulated by fishes via different exposure routes, causing several adverse effects. In the present study, the dose-dependent cytotoxicity of 8−10 µm polypropylene microplastics (PP-MPs), at concentrations of 1 mg/g (low dose) and 10 mg/g dry food (high dose), was evaluated in the liver and gill tissues of two fish species, the zebrafish (Danio rerio) and the freshwater perch (Perca fluviatilis). According to our results, the inclusion of PP-MPs in the feed of D. rerio and P. fluviatilis hampered the cellular function of the gills and hepatic cells by lipid peroxidation, DNA damage, protein ubiquitination, apoptosis, autophagy, and changes in metabolite concentration, providing evidence that the toxicity of PP-MPs is dose dependent. With regard to the individual assays tested in the present study, the biggest impact was observed in DNA damage, which exhibited a maximum increase of 18.34-fold in the liver of D. rerio. The sensitivity of the two fish species studied differed, while no clear tissue specificity in both fish species was observed. The metabolome of both tissues was altered in both treatments, while tryptophan and nicotinic acid exhibited the greatest decrease among all metabolites in all treatments in comparison to the control. The battery of biomarkers used in the present study as well as metabolomic changes could be suggested as early-warning signals for the assessment of the aquatic environment quality against MPs. In addition, our results contribute to the elucidation of the mechanism induced by nanomaterials on tissues of aquatic organisms, since comprehending the magnitude of their impact on aquatic ecosystems is of great importance.


Assuntos
Microplásticos , Poluentes Químicos da Água , Animais , Microplásticos/toxicidade , Plásticos/metabolismo , Peixe-Zebra/metabolismo , Polipropilenos , Ecossistema , Poluentes Químicos da Água/análise , Água Doce
3.
Molecules ; 27(19)2022 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-36234843

RESUMO

High concentrations of antibiotics have been identified in aqueous media, which has diminished the quality of water resources. These compounds are usually highly toxic and have low biodegradability, and there have been reports about their mutagenic or carcinogenic effects. The aim of this study was to apply zero-valent iron-oxide nanoparticles in the presence of hydrogen peroxide and the sonolysis process for the removal of the amoxicillin antibiotic from aqueous media. In this study, zero-valent iron nanoparticles were prepared by an iron chloride reduction method in the presence of sodium borohydride (NaBH4), and the obtained nanoparticles were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and vibrating-sample magnetometry (VSM). Then, using a Fenton-like process, synthetic wastewater containing 100 to 500 mg/L amoxicillin antibiotic was investigated, and the effects of different parameters, such as the frequency (1 and 2 kHz), contact time (15 to 120 min), the concentration of hydrogen peroxide (0.3%, 0.5%, and 6%), the dose of zero-valent iron nanoparticles (0.05, 0.1, 0.5 g/L), and pH (3, 5, 10) were thoroughly studied. A pH of 3, hydrogen peroxide concentration of 3%, ultrasonic-wave frequency of 130 kHz, zero-valent iron nanoparticles of 0.5 g/L, and contaminant concentration of 100 mg/L were obtained as the optimal conditions of the combined US/H2O2/nZVI process. Under the optimal conditions of the combined process of zero-valent iron nanoparticles and hydrogen peroxide in the presence of ultrasonic waves, a 99.7% removal efficiency of amoxicillin was achieved in 120 min. The results show that the combined US/H2O2/nZVI process could be successfully used to remove environmental contaminants, including antibiotics such as amoxicillin, with a high removal percentage.


Assuntos
Nanopartículas , Poluentes Químicos da Água , Amoxicilina , Antibacterianos , Cloretos , Peróxido de Hidrogênio/química , Ferro/química , Águas Residuárias/química , Água , Poluentes Químicos da Água/química
4.
Nanomaterials (Basel) ; 12(17)2022 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-36080086

RESUMO

Considering the risk associated with exposure to benzene and toluene in water resources, researchers have been motivated to conduct studies to remove them from aqueous solutions. Thus, by performing the present study, the potential of Fe3O4/zeolite imidazolate framework nanoparticles (Fe3O4@ZIF-8) was evaluated for the adsorption of benzene and toluene. Accordingly, the solution pH, Fe3O4@ZIF-8 dosage, mixing time, concentration of benzene and toluene, and temperature, were the parameters considered for conducting the batch experiments, for which their effect on adsorption efficiency was evaluated. Our conducted experiments introduced the neutral pH as the best pH range to obtain the maximum removal. Fitting the adsorption data into the various models revealed the aptness of the Langmuir isotherm equation in describing experimental information and highest adsorption capacity; for benzene it was 129.4, 134.2, 137.3, and 148.2 mg g-1, but for toluene it was 118.4, 125.2, 129.6, and 133.1 mg g-1, for temperature 20, 30, 40, and 50 °C, respectively. Using obtained optimal conditions, the adsorption efficiencies of benzene and toluene were obtained to be 98.4% and 93.1%, respectively. Kinetic studies showed acceptable coefficients for PSO kinetics and confirmed its suitability. Also, the recyclability results showed that for six consecutive periods of the adsorption-desorption process, the percentage of removal decreased by only 6% for benzene and toluene. Moreover, calculating thermodynamic parameter changes for benzene and toluene removal confirmed the favorability and spontaneity of the studied process and its endothermic nature. Considering the above findings, Fe3O4@ZIF-8 was found to be an operative adsorbent for removing pollutants.

5.
Chem Biol Interact ; 361: 109964, 2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35513013

RESUMO

Aptamers are single-stranded oligonucleotides that link to various substrates with great affinity and selectivity, including small molecules, peptides, proteins, cells, and tissues. For this reason, they can be used as imaging agents for cancer imaging techniques. Multifunctional nanomaterials combined with imaging probes and drugs are promising cancer diagnosis and treatment candidates. On the other hand, carbon-based nanomaterials (CNMs), including such as fullerene, carbon nanotubes, carbon-based quantum dots, carbon nanohorns, graphene oxide and its derivatives carbon nanodots, and nanodiamonds, are sort of smart materials that can be used in a variety of theranostic applications, including photo-triggered therapies. The remarkable physical characteristics, functionalizable chemistry, biocompatibility, and optical properties of these nanoparticles have enabled their utilization in less-invasive therapies. The theranostic agents that emerged by combining aptamers with CNMs have opened a novel alternative for personified medicine of cancer, target-specific imaging, and label-free diagnosis of a broad range of cancers, as well as pathogens. Aptamer-functionalized CNMs have been used as nanovesicles for targeted delivery of anti-cancer agents (i.e., doxorubicin and 5-fluorouracil) to tumor sites. Furthermore, these CNMs conjugated with aptamers have shown great advantages over standard CNMs to sensitively detect Mycobacterium tuberculosis, Escherichia coli, staphylococcus aureus, Vibrio parahaemolyticus, Salmonella typhimurium, Pseudomonas aeruginosa, and Citrobacter freundii. Regrettably, CNMs can form compounds defined as NOAA (nano-objects, and their aggregates and agglomerates larger than 100 nm), that accumulate in the body and cause toxic effects. Surface modification and pretreatment with albumin avoid agglomeration and increase the dispersibility of CNMs, so it is needed to guarantee the desirable interactions between functionalized CNMs and blood plasma proteins. This preliminary review aimed to comprehensively discuss the features and uses of aptamer-conjugated CNMs to manage cancer and bacterial infections.


Assuntos
Nanoestruturas , Nanotubos de Carbono , Neoplasias , Bactérias , Humanos , Nanoestruturas/química , Nanoestruturas/uso terapêutico , Nanotubos de Carbono/química , Neoplasias/diagnóstico por imagem , Neoplasias/tratamento farmacológico , Oligonucleotídeos , Medicina de Precisão
6.
Polymers (Basel) ; 13(7)2021 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-33916426

RESUMO

Dyes are known as one of the most dangerous industrial pollutants which can cause skin diseases, allergy, and provoke cancer and mutation in humans. Therefore, one of the important environmental issues is the effective removal of dyes from industrial wastewater. In the current work, BaFe12O19/CoFe2O4@polyethylene glycol (abbreviated as BFO/CFO@PEG) nanocomposite was synthesized and evaluated regarding its capacity for adsorptive removal of a model dye Acid Blue 92 (denoted as AB92) from aqueous solutions. The characteristics of the prepared nanocomposite was determined by tests such as X-ray diffraction (XRD), scanning electron microscope (SEM), vibration sample magnetization (VSM), and Fourier transform infrared spectroscopy (FTIR). The effects of conditional parameters including pH (2-12), initial concentration of dye (20-100 mg/L), adsorbent dosage (0.02-0.1 g/L) and contact time (0-180 min) on the adsorption of dye were investigated and then optimized. The results indicated that with the increase of the adsorbent dosage from 0.02 to 0.1 g/L, the removal efficiency increased from 74.1% to 78.6%, and the adsorbed amount decreased from 148.25 to 31.44 mg/g. The maximum removal efficiency (77.54%) and adsorption capacity (31.02 mg/g) were observed at pH 2. Therefore, the general optimization conditions revealed that the maximum adsorption efficiency of dye was obtained in condition of initial concentration of 20 mg/L, contact time of 1 h and pH of solution equal 2. The adsorption isotherm and kinetic data were evaluated using a series of models. The pseudo-second order kinetic model and Freundlich isotherm model show the best fitting with experimental data with R2∼0.999.

7.
Life Sci ; 276: 119420, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-33785340

RESUMO

Quercetin (Q) is formulated into oil-in-water F127 microemulsions to improve its bioavailability. The size of the Q-loaded microemulsions system was about 8 nm by dynamic light scattering analysis. To compare antioxidant activity of bulk solution and microemulsion of Q, free radical scavenging activity was evaluated against 2,2-diphenyl-1-picrylhydrazyl (DPPH). The IC50 values were 56.77 and 187.68 µM, respectively. The drug in the bulk form released 16.34 times faster than microemulsion form. Although gentamicin (GM) has potent efficacy against gram-negative bacteria, it induces renal toxicity. Poor solubility and low bioavailability of Q as a bioflavonoid with potent antioxidant activity, limit its therapeutic application. We aimed to compare the effect of free Q and nanoencapsulated (NEQ) against GM-induced renal damage in Wistar rats. Forty-two animals were divided into six groups. Control and GM groups received apo-nanomicelles and GM (100 mg/kg) for 10 days. Two groups received Q (50 mg/kg, i.g.) and NEQ (50 mg/kg, i.g.) respectively for 10 days. Remaining two groups received Q and NEQ (50 mg/kg, i.g.) plus GM (100 mg/kg, i.p.) simultaneously for 10 days. After the experiments, serum and kidneys were used for biochemical, molecular and histological examinations. Immunohistochemical analysis was performed to explore kidney injury molecule-1 (KIM-1) expression as a specific protein biomarker of renal injury. Our findings indicated oxidative stress and altered histological features in renal tissue with deviated serum renal biomarkers in GM-treated rats. Although Q treatment in GM group tried to protect against GM-induced nephrotoxicity, but there were still differences compared to control rats. However, NEQ administration corrected elevations in the levels of urea, creatinine, uric acid and decrements in serum total proteins of GM group. Meanwhile, NEQ restored renal oxidative injury in GM rats through attenuation of lipid peroxidation and enhancement of antioxidant defense systems, glutathione, catalase and superoxide dismutase. NEQ could also normalize GM-induced abnormal renal histology features including fibrosis. Furthermore, the result of immunohistochemistry study confirmed these findings by undetecting KIM-1 expression in NEQ treated GM group, meanwhile showing this renal biomarker in GM and Q treated GM groups. Therefore, NEQ seems to be useful in protecting against renal oxidative stress and kidney damage in a rat model of GM nephrotoxicity which deserve further evaluations.


Assuntos
Injúria Renal Aguda/tratamento farmacológico , Antioxidantes/farmacologia , Gentamicinas/toxicidade , Polietilenos/química , Polipropilenos/química , Substâncias Protetoras/farmacologia , Quercetina/farmacologia , Injúria Renal Aguda/induzido quimicamente , Injúria Renal Aguda/metabolismo , Injúria Renal Aguda/patologia , Animais , Antioxidantes/administração & dosagem , Antioxidantes/química , Biomarcadores/análise , Nitrogênio da Ureia Sanguínea , Glutationa/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Substâncias Protetoras/administração & dosagem , Substâncias Protetoras/química , Quercetina/administração & dosagem , Quercetina/química , Ratos , Ratos Wistar
8.
Life Sci ; 270: 119146, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33545199

RESUMO

Deferasirox (DFX) was formulated into oil-in-water microemulsions in the presence of pluronicto improve its oral bioavailability. The size of the DFX-loadedmicroemulsions system measured by dynamic light scattering (DLS) was about 9 nm. The anti-proliferative and anti-lipid peroxidation effects of DFX and DFX-loaded microemulsions were assessed on Human umbilical vein endothelial (HUVEC) cells. Our in vitro results showed that HUVEC cells are more susceptible to free DFX as compared to DFX-loaded microemulsions. Although both free and encapsulated DFX attenuated FeCl3-induced lipid peroxidation, after 6 and 12 h treatment, DFX-loaded microemulsions did not appear a better ameliorator than DFX. To compare the in vivo efficacy of free DFX and DFX-loaded microemulsions in iron- intoxicated rats, the animals were orally administered with 25 mg/kg DFX, or 25 mg/kg DFX microemulsions, respectively. In vivo gavage handling of free DFX significantly increased serum biochemical parameters. There was also a significant increase in lipid peroxidation in rats who received free DFX compared to those in the control rats. Treatment with DFX-loaded microemulsions restored the elevated levels of serum AST, ALT, and creatinine levels and also reduced liver MDA content. Histopathological analysis of renal and hepatic tissues was in line with the biochemical results. In conclusion, DFX-loaded microemulsions induce less toxicity than free DFX and appear a more desirable and safer drug carrier in combating the iron-overload complications. Theoretical simulations are performed to get better insight regarding interactions between DFX and surfactant F127.


Assuntos
Deferasirox/farmacologia , Sistemas de Liberação de Medicamentos/métodos , Sobrecarga de Ferro/tratamento farmacológico , Animais , Deferasirox/metabolismo , Emulsões/farmacologia , Células Endoteliais da Veia Umbilical Humana , Humanos , Ferro/análise , Ferro/metabolismo , Ferro/toxicidade , Quelantes de Ferro/farmacologia , Sobrecarga de Ferro/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Masculino , Micelas , Ratos , Ratos Wistar
9.
Polymers (Basel) ; 13(2)2021 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-33440888

RESUMO

In this experimental study, the use of 5-hydroxymethyl-furfural (HMF) organic compound as a grafting agent to chitosan natural polymer (CS) was examined. One optimized chitosan derivative was synthesized, and then tested (CS-HMF), in order to uptake nickel, mercury, and barium metal ions from single- and triple-component (multi-component) aqueous solutions. The characterization of the material before and after the metal uptake was achieved by scanning electron microscopy (SEM). The ability of the adsorption of CS-HMF was tested at pH = 6. The adjusting of temperature from 25 to 65 °C caused the increase in the adsorption capacity. The equilibrium data were fitted to the models of Langmuir and Freundlich, while the data from kinetic experiments were fitted to pseudo-1st and pseudo-2nd order models. The best fitting was achieved for the Langmuir model (higher R2). The adsorption capacity for nickel, mercury, and barium removal at 25 °C (single component) was 147, 107, and 64 (mg/g), respectively. However, the total adsorption capacity for the multi-component was 204 mg/g. A thermodynamic study was also done, and the values of ΔG0, ΔH0, and ΔS0 were evaluated.

10.
Life Sci ; 266: 118914, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33340527

RESUMO

To overcome the drawbacks of conventional delivery, this review spotlights a number of nanoscale drug delivery systems, including nanoparticles, liposomes, nano micelles, branched dendrimers, nanocapsules, and nanostructured lipid formulations for the targeted therapy of ovarian cancer. These nanoformulations offer numerous advantages to promote therapeutic drug delivery such as nontoxicity, biocompatibility, good biodegradability, increased therapeutic impact than free drugs, and non-inflammatory effects. Importantly, the development of specific ligands functionalized nanoformulations enable preferential targeting of ovarian tumors and eventually amplify the therapeutic potential compared to nonfunctionalized counterparts. Ovarian cancer is typically identified by biomarker assessment such as CA125, HE4, Mucin 1, and prostatic. There is, nevertheless, a tremendous demand for less costly, faster, and compact medical tools, both for timely detection and ovarian cancer control. This paper explored multiple types of tumor marker-based on nanomaterial biosensors. Initially, we mention different forms of ovarian cancer biomarkers involving CA125, human epididymis protein 4 (HE4), mucin 1 (MUC1), and prostate. It is accompanied by a brief description of new nanotechnology methods for diagnosis. Nanobiosensors for evaluating ovarian cancer biomarkers can be categorized based on electrochemical, optical, paper-based, giant magnetoresistive, and lab-on-a-chip devices.


Assuntos
Antineoplásicos/administração & dosagem , Biomarcadores Tumorais/análise , Sistemas de Liberação de Medicamentos , Nanopartículas/administração & dosagem , Nanotecnologia/métodos , Neoplasias Ovarianas/diagnóstico , Neoplasias Ovarianas/tratamento farmacológico , Antineoplásicos/química , Feminino , Humanos , Nanopartículas/química , Neoplasias Ovarianas/patologia
11.
Nanomaterials (Basel) ; 10(9)2020 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-32872181

RESUMO

The fabrication and development of nanomaterials for the treatment of prostate cancer have gained significant appraisal in recent years. Advancements in synthesis of organic and inorganic nanomaterials with charge, particle size, specified geometry, ligand attachment etc have resulted in greater biocompatibility and active targeting at cancer site. Despite all of the advances made over the years in discovering drugs, methods, and new biomarkers for cancer of the prostate (PCa), PCa remains one of the most troubling cancers among people. Early on, effective diagnosis is an essential part of treating prostate cancer. Prostate-specific antigen (PSA) or serum prostate-specific antigen is the best serum marker widely accessible for diagnosis of PCa. Numerous efforts have been made over the past decade to design new biosensor-based strategies for biomolecules detection and PSA miniaturization biomarkers. The growing nanotechnology is expected to have a significant effect in the immediate future on scientific research and healthcare. Nanotechnology is thus predicted to find a way to solve one of the most and long-standing problem, "early cancer detection". For early diagnosis of PCa biomarkers, different nanoparticles with different approaches have been used. In this review, we provide a brief description of the latest achievements and advances in the use of nanoparticles for PCa biomarker diagnosis.

12.
Polymers (Basel) ; 12(6)2020 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-32580366

RESUMO

In the past few decades, polymeric nanocarriers have been recognized as promising tools and have gained attention from researchers for their potential to efficiently deliver bioactive compounds, including drugs, proteins, genes, nucleic acids, etc., in pharmaceutical and biomedical applications. Remarkably, these polymeric nanocarriers could be further modified as stimuli-responsive systems based on the mechanism of triggered release, i.e., response to a specific stimulus, either endogenous (pH, enzymes, temperature, redox values, hypoxia, glucose levels) or exogenous (light, magnetism, ultrasound, electrical pulses) for the effective biodistribution and controlled release of drugs or genes at specific sites. Various nanoparticles (NPs) have been functionalized and used as templates for imaging systems in the form of metallic NPs, dendrimers, polymeric NPs, quantum dots, and liposomes. The use of polymeric nanocarriers for imaging and to deliver active compounds has attracted considerable interest in various cancer therapy fields. So-called smart nanopolymer systems are built to respond to certain stimuli such as temperature, pH, light intensity and wavelength, and electrical, magnetic and ultrasonic fields. Many imaging techniques have been explored including optical imaging, magnetic resonance imaging (MRI), nuclear imaging, ultrasound, photoacoustic imaging (PAI), single photon emission computed tomography (SPECT), and positron emission tomography (PET). This review reports on the most recent developments in imaging methods by analyzing examples of smart nanopolymers that can be imaged using one or more imaging techniques. Unique features, including nontoxicity, water solubility, biocompatibility, and the presence of multiple functional groups, designate polymeric nanocues as attractive nanomedicine candidates. In this context, we summarize various classes of multifunctional, polymeric, nano-sized formulations such as liposomes, micelles, nanogels, and dendrimers.

13.
Carbohydr Polym ; 234: 115890, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32070510

RESUMO

A novel adsorbent material composed of chitosan (Cs), polyvinyl alcohol (PVA) and polyethylene glycol (PEG) was prepared in hydrogel bead form to efficiently remove copper ions from aqueous solutions. The properties of the composite were characterized by scanning electronic microscopy (SEM), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), atomic force microscopy (AFM) and Fourier transform infrared spectroscopy (FTIR). The adsorption behavior of Cu(II) onto Cs/PVA/PEG beads was studied as a function of solution pH, temperature and contact time. The maximum adsorption was observed equal to 99.99 % for initial copper ion concentration of 25 mg/L at pH 5, temperature 45 °C, 5 h as contact time and 1 g/L of adsorbent dose. Langmuir isotherm and pseudo-second kinetic model fitted the experimental data sufficiently. Thermodynamic studies indicated that the process was spontaneous and endothermic. Cs/PVA/PEG beads can act as an effective adsorbent for the removal of Cu(II) from aqueous solution.

14.
Chemosphere ; 234: 746-755, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31238270

RESUMO

Recently the synthesis and application of bio-based composite materials, which contain polymeric and inorganic units such as TiO2, has gained much attention in the field of water/wastewater treatment, due to their better (and more practical) performance parameters. In the present study, recycled poly(ethylene terephthalate) (PET) has been used and evaluated as supporting polymer for Aeroxide P25 TiO2 immobilization. PET-TiO2 composite films were synthesized at different TiO2 content (10%, 30% and 47% TiO2) and characterized with different techniques such as X-ray Powder Diffraction (XRD), Thermogravimetric analysis (TGA), Differential scanning calorimetry (DSC), Scanning electron microscopy (SEM), etc. The photocatalytic activity of the new (synthesized) bio-based TiO2 composite films was investigated under simulated solar irradiation for the degradation of a mixture of antibiotic pharmaceuticals (Isoniazid, Metronizadole, Sulfadiazine, Sulfamethoxazole, Trimethoprim, Norfloxacin, Moxifloxacin and Lincomycin). The immobilization of TiO2 was successful in all cases and by increasing the photocatalyst concentration results in higher photocatalytic efficiencies. The new composite films were tested two times to assess their reusability, which found to be better for PET-10%-TiO2 composite films; therefore the latter has been used for further investigation thus exhibiting good stability even after five cycles. The results showed that PET-10%-TiO2 was efficient in degrading the antibiotic mixture in water and in wastewater matrix.


Assuntos
Antibacterianos/química , Polietilenotereftalatos/química , Purificação da Água/métodos , Catálise , Microscopia Eletrônica de Varredura , Nanocompostos , Fotólise , Titânio/química , Águas Residuárias/química , Poluentes Químicos da Água/química , Difração de Raios X
15.
Molecules ; 24(3)2019 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-30720725

RESUMO

In the present study, polymer supported nanocomposites, consisting of bio-based poly(ethylene furanoate) polyester and TiO2 nanoparticles, were prepared and evaluated as effective photocatalysts for anti-inflammatory/analgesic drug removal. Nanocomposites were prepared by the solvent evaporation method containing 5, 10, 15, and 20 wt% TiO2 and characterized using Fourier Transform Infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). Thin films of them have been prepared by the melt press and optimization of the photocatalytic procedure was conducted for the most efficient synthesized photocatalyst. Finally, mineralization was evaluated by means of Total organic carbon (TOC) reduction and ion release, while the transformation products (TPs) generated during the photocatalytic procedure were identified by high-resolution mass spectrometry.


Assuntos
Analgésicos/química , Anti-Inflamatórios não Esteroides/química , Nanocompostos/química , Poliésteres/química , Polietileno/química , Titânio/química , Analgésicos/administração & dosagem , Anti-Inflamatórios não Esteroides/administração & dosagem , Varredura Diferencial de Calorimetria , Catálise , Técnicas de Química Sintética , Evolução Molecular , Processos Fotoquímicos , Polietileno/síntese química , Espectroscopia de Infravermelho com Transformada de Fourier
16.
Carbohydr Polym ; 91(1): 198-208, 2013 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-23044123

RESUMO

In this study, two types of novel molecularly imprinted polymers (MIPs) were prepared, for toxic and carcinogenic dyes adsorption. Substrates of the polymeric matrix of the two MIPs were ß-cyclodextrin and chitosan. The conditions in the polymerization/imprinting stage and in the rebinding/adsorption step were optimized. The effect of a range of parameters (polymer, cross-linker, and initiator concentrations, reaction time and pH) on the selectivity and adsorption capacity of the dye-MIPs were investigated. Their dye rebinding properties were demonstrated by equilibrium batch experiments (fitting with Freundlich model) and their kinetic rates were exported by the pseudo-first order model. Additionally, a thermodynamic evaluation was carried out through the determination of enthalpy, entropy, and free energy. The selectivity of MIPs was elucidated by their different rebinding capabilities in a trichromatic mixture (composed of related structurally dyes). Regeneration/reuse of the dye-loaded polymers was evaluated via sequential adsorption-desorption cycles.


Assuntos
Quitosana/química , Corantes/química , Impressão Molecular/métodos , beta-Ciclodextrinas/química , Adsorção , Concentração de Íons de Hidrogênio , Cinética , Polimerização
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