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1.
Water Sci Technol ; 81(4): 694-708, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-32460273

RESUMEN

Mass production of nanomaterials to remove pollutants from water still faces many challenges, mainly due to the complexity of the synthesis methods involved and the use of dangerous reagents. The green method of preparation of nanomaterials from plants can effectively solve these problems. Fe,Cu oxide nanocomposites (Fe-Cu-NCs) were synthesized by a green and single-step method using loquat leaf extracts, and were used as an adsorbent for removal of Norfloxacin (NOR) and Ciprofloxacin (CIP) from aqueous solution. The synthesized adsorbent showed excellent adsorption properties for NOR and CIP. The experimental equilibrium data fitted the Redlich-Peterson and Koble-Corrigan models well and the maximum adsorption capacities of Fe-Cu-NCs calculated by the Langmuir model for NOR and CIP were 1.182 mmol/g and 1.103 mmol/g, respectively, at 293 K. Additionally, the morphologies and properties of Fe-Cu-NCs were characterized by transmission electron microscopy (TEM), scanning electron microscopy X-ray energy-dispersive spectroscopy (SEM-EDS), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) analysis and the adsorption mechanism of NOR and CIP onto Fe-Cu-NCs was discussed. Thermodynamic parameters revealed that the adsorption process was spontaneous and endothermic. This study indicated that Fe-Cu-NCs are a potential adsorbent and provide a simple and convenient strategy for the purification of antibiotics-laden wastewater.


Asunto(s)
Eriobotrya , Nanocompuestos , Contaminantes Químicos del Agua , Adsorción , Ciprofloxacina , Cinética , Norfloxacino , Óxidos , Extractos Vegetales , Espectroscopía Infrarroja por Transformada de Fourier
2.
Water Sci Technol ; 77(9-10): 2517-2527, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29893741

RESUMEN

The most ideal conditions for preparing activated carbon from grapefruit peel (GPAC) were studied using NH4H2PO4 as a chemical activating agent and the obtained material was characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and Brunauer-Emmett-Teller (BET) analysis. The adsorption capacity of the resulting material has been checked using three phenolic compounds (pyrocatechol (CA), 4-chlorophenol (4-CP) and 2,4-dichlorophenol (2,4-DCP)). The adsorption characteristics of phenolic compounds from aqueous solution by GPAC have been investigated as a function of contact time, pH, initial concentration and temperature. The equilibrium experimental data fitted well with Freundlich and Koble-Corrigan isotherms. The adsorption of the three phenolic compounds on GPAC fitted well with pseudo-second-order kinetic model. Different thermodynamic parameters were also evaluated and it was found that the adsorption was spontaneous, feasible and endothermic in nature. Adsorbents were regenerated by 0.1 mol/L NaOH and GPAC could be reused in phenolic compounds removal.


Asunto(s)
Carbón Orgánico/química , Citrus paradisi/química , Fenoles/química , Contaminantes Químicos del Agua/química , Adsorción , Concentración de Iones de Hidrógeno , Cinética , Espectroscopía Infrarroja por Transformada de Fourier , Temperatura , Termodinámica , Eliminación de Residuos Líquidos/métodos
3.
Water Sci Technol ; 77(11-12): 2555-2565, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29944121

RESUMEN

Salix psammophila (SP), a solid waste abundantly available, was applied as a precursor to prepare the activated carbon by chemical activation method using phosphoric acid (H3PO4). Response surface methodology based on Box-Behnken design was used to optimize the prepared conditions of activated carbon. The effects of concentration of H3PO4, activation temperature and activation time on the adsorption performance (expressed by the adsorption capacity of ciprofloxacin hydrochloride (CIP) and norfloxacin (NOR)) were investigated. The optimum conditions were obtained using H3PO4 concentration of 67.83%, activation temperature of 567.44 °C and activation time of 86.61 min. The optimum activated carbon (SPAC) was characterized with scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), Brunauer-Emmett-Teller (BET) and Fourier transform infrared spectroscopy (FTIR). The adsorption behavior of CIP and NOR on SPAC was carried out and the mechanisms for the adsorption process were proposed. The equilibrium data were fitted by the Freundlich and Langmuir isotherm models, which resulted in 251.9 mg/g and 366.9 mg/g of the maximum monolayer adsorption for CIP and NOR at 25 °C, respectively. The best fitted kinetic model was pseudo-second-order, implying that chemisorption dominated in the adsorption process. This study indicated that activated carbon based on Salix psammophila (SPAC) was an excellent adsorbent for removing fluoroquinolone antibiotics from aqueous solutions.


Asunto(s)
Antibacterianos/aislamiento & purificación , Carbón Orgánico/química , Fluoroquinolonas/aislamiento & purificación , Salix/química , Residuos Sólidos , Adsorción , Ciprofloxacina/aislamiento & purificación , Fluoroquinolonas/química , Cinética , Microscopía Electrónica de Rastreo , Norfloxacino/aislamiento & purificación , Ácidos Fosfóricos/química , Espectrometría por Rayos X/métodos , Espectroscopía Infrarroja por Transformada de Fourier , Temperatura , Administración de Residuos/métodos , Contaminantes Químicos del Agua/química , Contaminantes Químicos del Agua/aislamiento & purificación
4.
Theriogenology ; 142: 26-33, 2020 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-31574397

RESUMEN

Asiatic acid is a pentacyclic triterpene enriched in the medicinal herb Centella asiatica, and it has been suggested to possess free radical scavenging and anti-apoptotic properties. The purpose of the current study was to explore the effects of asiatic acid on porcine early-stage embryonic development and the potential mechanisms for any observed effects. The results showed that 10 µM asiatic acid supplementation during the in vitro culture period dramatically improved developmental competence in porcine embryos derived from parthenogenetic activation (PA), somatic cell nuclear transfer (SCNT) and in vitro fertilization (IVF). Further analysis revealed that asiatic acid attenuated H2O2-induced intracellular reactive oxygen species (ROS) generation. Notably, asiatic acid not only enhanced intracellular GSH levels but also attenuated mitochondrial dysfunction. Gene expression analysis revealed that asiatic acid upregulated expression of the antioxidant-related gene Sod-1 and the blastocyst formation related gene Cox-2, while downregulating expression of the apoptosis-related gene Caspase-9 in SCNT blastocysts. These results suggest that asiatic acid exerts beneficial effects on early embryonic development in porcine embryos and that asiatic acid may be useful for improving the in vitro production of porcine embryos.


Asunto(s)
Técnicas de Cultivo de Embriones/veterinaria , Desarrollo Embrionario/efectos de los fármacos , Fertilización In Vitro/veterinaria , Técnicas de Transferencia Nuclear/veterinaria , Triterpenos Pentacíclicos/farmacología , Porcinos/embriología , Animales , Medios de Cultivo/química , Glutatión/metabolismo , Potencial de la Membrana Mitocondrial , Partenogénesis , Especies Reactivas de Oxígeno
5.
Data Brief ; 25: 103848, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31304206

RESUMEN

The data presented in this article are related to the research paper entitled "Pyrometamorphic aureoles of Cretaceous sandstones and shales by Cenozoic basic intrusions, NE Brazil: Petrographic, textural, chemical and experimental approaches" Souza et al., 2018. Here, we report the complete data set for natural minerals and rocks as well as for experimental runs. These data include detailed oxide composition of minerals and glassy groundmass of the samples studied from electron microprobe and scanning electron microscopy analyzes. Rock samples and minerals are separated according to the protolith (sandstone, shale), pyrometamorphic rock (dark and light buchites, and silica-rich types), intrusion (basalt, diabase) that induced the pyrometamorphic events, and experimental results (microphenocrysts, glass).

6.
Sci Total Environ ; 639: 428-437, 2018 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-29793083

RESUMEN

Polydopamine microspheres (PDMPs) synthesized by a facile solution oxidation method were adopted as a potential adsorbent for the removal of Norfloxacin (NOR) from aqueous solution. The morphologies and properties of PDMPs were characterized using TEM, SEM, FTIR and pHPZC. Parameters effects such as contact time, initial pH, initial concentration and ionic strength on the adsorption capacity of NOR onto PDMPs were studied. To maximize NOR removal from liquid phase, Box-Behnken experimental design (BBD) combined with response surface modeling (RSM) was employed based on the 17 preliminary experiments at 308 K. Optimum contact time, initial NOR concentration and initial pH value were found to be 97 min, 303 mg·L-1 and 6.6, respectively, the corresponding NOR removal capacity was found to be 307 mg·g-1. Batch adsorption experiments under the optimal conditions were conducted to investigate kinetics, thermodynamics and adsorption isotherm. Kinetic analysis confirmed that the kinetic data were well described by Pseudo-second order model. The experimental equilibrium data were well fitted by Langmuir, Redlich-Peterson, Koble-Corrigan and Dubinin-Radushkevich models. Thermodynamic parameters such as Gibbs free energy, enthalpy and entropy were calculated and the results indicated that the NOR adsorption onto PDMPs was spontaneous and endothermic. The adsorption process may be attributed to the electrostatic interaction, the formation of hydrogen bonds or π-π stacking interactions among the polydopamine (PDA) and NOR molecule.


Asunto(s)
Indoles/química , Microesferas , Norfloxacino/química , Polímeros/química , Contaminantes Químicos del Agua/química , Adsorción , Concentración de Iones de Hidrógeno , Indoles/análisis , Cinética , Norfloxacino/análisis , Polímeros/análisis , Soluciones , Termodinámica , Contaminantes Químicos del Agua/análisis
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