RESUMO
In this study, the effect factors and mechanisms of doxycycline hydrochloride (DOX) adsorption on copper nitrate modified biochar (Cu-BC) was investigated. Cu-BC absorbent was synthesized through calcination of peanut shells biomass at 450°C and then impregnation with copper nitrate. The Cu-BC has exhibited excellent sorption efficiency about 93.22% of doxycycline hydrochloride from aqueous solution, which was double higher than that of the unmodified biochar. The experimental results suggest that the adsorption efficiency of DOX on the Cu-BC is dominated by the strong complexation, electrostatic interactions between DOX molecules and the Cu-BC samples. Comprehensively considering the cost, efficiency and the application to realistic water, the Cu-BC hold the significant potential for enhancing the effectiveness to remove DOX from water.
Assuntos
Carvão Vegetal/química , Cobre/química , Doxiciclina/isolamento & purificação , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos , Adsorção , ÁguaRESUMO
A novel magnetic nanomaterial was synthesized by grafting nitrilotriacetic acid to magnetic graphene oxide (NDMGO), which was applied as an adsorbent for removing tetracycline (TC) from aqueous solutions. The nanomaterial was characterized using TG-DTA, SEM, TEM, XRD, VSM, XPS, Raman, BET surface area and zeta potential measurements. Several experimental conditions (solution pH, adsorption time, temperature, ionic strength and foreign ions) affecting the adsorption process were investigated. The results showed that the TC adsorption capacity could be affected by solution pH. The adsorption capacity of TC increased rapidly in the initial 20min and finally reached equilibrium was about 600min. The pseudo-second-order kinetics provided the better correlation for the experiment data. Various thermodynamic parameters indicated that the adsorption was a spontaneous and endothermic process. The presence of NaCl and background electrolytes in the solution had a slight influence on TC adsorption. Hydrogen bonds, amidation reaction, π-π and cation-π interaction between NDMGO and TC could be used to explain the adsorption mechanism. The regeneration experiment demonstrated that this nanomaterial possessed an excellent regeneration performance. Based on the experimental results and comparative analysis with other adsorbents, the NDMGO was a high-efficiency and reusable adsorbent for TC pollution control.
Assuntos
Grafite/química , Nanopartículas de Magnetita/química , Nanocompostos/química , Ácido Nitrilotriacético/química , Tetraciclina/isolamento & purificação , Poluentes Químicos da Água/isolamento & purificação , Adsorção , Reutilização de Equipamento , Humanos , Ligação de Hidrogênio , Concentração de Íons de Hidrogênio , Cinética , Nanopartículas de Magnetita/ultraestrutura , Nanocompostos/ultraestrutura , Concentração Osmolar , Óxidos , Cloreto de Sódio/química , Temperatura , Termodinâmica , Águas Residuárias/química , Purificação da Água/métodosRESUMO
<p><b>OBJECTIVE</b>To study the chemical constituents from the stems and leaves of Calophyllum inophyllum.</p><p><b>METHOD</b>The compounds were isolated by column chromatography on silica gel, Sephadex LH-20 and preparative TLC. Their structures were elucidated by chemical methods and NMR, MS spectroscopic data.</p><p><b>RESULT</b>Nine compounds were identified as 2-hydroxyxanthone (1), 4-hydroxyxanthone (2), 1, 5-dihydroxyxanthone (3), 1, 7-dihydroxyxanthone (4), 1, 3, 5-trihydroxy-2-methoxyxanthone (5), 6-deoxyjacareubin (6), amentoflavone (7), kaempferol-3-O-alpha-L-rhamnoside (8) and quercetin-3-O-alpha-L-rhamnoside (9).</p><p><b>CONCLUSION</b>Compounds 8 and 9 were isolated from the genus Calophyllum and compounds 1, 2, 4-6 were isolated from this plant for the first time.</p>
Assuntos
Calophyllum , Química , Cromatografia , Métodos , Flavonoides , Química , Glicosídeos , Química , Quempferóis , Química , Espectroscopia de Ressonância Magnética , Métodos , Espectrometria de Massas , Métodos , Folhas de Planta , Química , Caules de Planta , Química , Plantas Medicinais , Química , Piranos , Química , Quercetina , Química , Xantenos , QuímicaRESUMO
Objective To evaluate the value of peripheral blood neutrophil CD_(64) level for early diagnosis of neonatal septicemia.Methods Thirty-six cases of neonatal septicemia were recruited into the study according to diagnostic criteria for neonatal septicemia:white blood cell count,C-reactive protein(CRP),platelet count,micro-erythrocyte sedimentatio rate(mESR) and blood culture;26 cases of hospitalized neonates with non-infectious diseases were enrolled as controls.The level of peripheral blood neutrophil CD_(64) was measured by flow cytometry.Results The level of peripheral blood neutrophil CD_(64) in septicemia patients were(60.37?22.70)mean fluorescence intensity(MFI),which were significantly higher than that of control group(23.14?5.10)MFI(P
