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1.
Environ Res ; 258: 119416, 2024 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-38885827

RESUMEN

To address the urgent need for efficient removal of lead-containing wastewater and reduce the risk of toxicity associated with heavy-metal wastewater contamination, materials with high removal rates and easy separation must be developed. Herein, a novel organic-inorganic hybrid material based on phosphorylated magnetic chitosan (MSCP) was synthesized and applied for the selective removal of lead (II) from wastewater. From the characterization and the experimental results can be obtained that the magnetic saturation strength of MSCP reaches 14.65 emu/g, which can be separated quickly and regenerated readily, and maintains high adsorption performance even after 5 cycles, indicating that the adsorbent possesses good magnetic separation performance and durability. Also, MSCP showed high selective adsorption performance for lead in the multiple metal ions coexistence solutions at pH 6.0 and room temperature, with an adsorption coefficient SPb-MSCP of 78.85%, which was much higher than that of MSC (the SPb-MSC was 11.59%). Additionally, in the single lead system, the sorption characteristics of Pb(II) on MSCP and MCP had obvious pH-responsiveness, and their adsorption capacity increased with the increase of solution pH, reaching the maximal values of 80.19 and 72.68 mg/g, respectively. It is noteworthy that the acid resistance of MSCP with an inert layer coated on the core is significantly improved, with almost no iron leaching from MSCP over the entire acidity range, while MCP has 7.63 mg/g of iron leaching at pH 1.0. Significantly, MSCP exhibited a maximum adsorption capacity of 102.04 mg/g, which matches the Langmuir model at pH 6.0 and 298.15 K, and points to the pseudo-second-order kinetics of the chemisorption process of Pb(II) on MSCP. These findings highlight the great potential of MSCP for Pb(II) removal from aqueous solution, making it a promising solution for Pb(II) contamination in wastewater.


Asunto(s)
Quitosano , Plomo , Fosfatos , Aguas Residuales , Contaminantes Químicos del Agua , Plomo/química , Plomo/aislamiento & purificación , Quitosano/química , Aguas Residuales/química , Contaminantes Químicos del Agua/química , Adsorción , Fosfatos/química , Concentración de Iones de Hidrógeno , Eliminación de Residuos Líquidos/métodos , Purificación del Agua/métodos
2.
Inorg Chem ; 62(11): 4485-4494, 2023 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-36893304

RESUMEN

A novel sulfur-bridged metal-organic framework (MOF) [Co(TIC4R-I)0.25Cl2]·3CH3OH (Co-TIC4R-I) based on thiacalix[4]arene derivatives was successfully obtained using a solvothermal method. Remarkably, adjacent TIC4R-I ligands were linked via Co(II) cations to form a three-dimensional (3D) microporous architecture. Subsequently, Co-TIC4R-I was modified on a glassy carbon electrode (Co-TIC4R-I/GCE) to produce an electrochemical sensor for the detection of heavy-metal ions (HMIs), namely, Cd2+, Pb2+, Cu2+, and Hg2+, in aqueous solutions. It was found that Co-TIC4R-I/GCE exhibited wide linear detection ranges of 0.10-17.00, 0.05-16.00, 0.05-10.00, and 0.80-15.00 µM for Cd2+, Pb2+, Cu2+, and Hg2+, respectively, in addition to low limit of detection (LOD) values of 0.017, 0.008, 0.016, and 0.007 µM. Moreover, the fabricated sensor employed for the simultaneous detection of these metals has achieved LOD values of 0.0067, 0.0027, 0.0064, and 0.0037 µM for Cd2+, Pb2+, Cu2+, and Hg2+, respectively. The sensor also exhibited satisfactory selectivity, reproducibility, and stability. Furthermore, the relative standard deviation (RSD) values of Cd2+, Pb2+, Cu2+, and Hg2+ were 3.29, 3.73, 3.11, and 1.97%, respectively. Moreover, the fabricated sensor could sensitively detect HMIs in various environmental samples. The high performance of the sensor was attributed to its sulfur adsorption sites and abundant phenyl rings. Overall, the sensor described herein provides an efficient method for the determination of extremely low concentrations of HMIs in aqueous samples.

3.
J Hazard Mater ; 447: 130760, 2023 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-36640512

RESUMEN

Coagulation-flocculation in industrial wastewater treatment drives environmental pollution from landfilling heavy metal-laden sludge. Efficient separation of the sludge is crucial for cost-effective metal recovery. This study explored a new separation method of Cu2+, Ni2+, Zn2+ and Cr3+ via self-floating metal hydroxides assisted by hollow glass microsphere (HGM) carriers. The amount of OH- was stoichiometric to the positive charges of metal ions, mixed with 1 mg mL-1 HGM, causing metal hydroxides to attach to HGM surface via heterogeneous nucleation. The self-floating system removed 37.5% and 14.0% more metals than sedimentation at 50 and 200 mg L-1 metal concentrations. HGM additions increased the particle size of metal hydroxides by up to 12.5 times to that of HGM at 18.8 ± 1.1 µm, benefiting their solid-liquid separation. By pumping the wastewater downward in column reactor at velocities equal to or less than the self-floating sludge, 96.4% metals were removed in continuous flow. The recovery rates of HGM and metals reached 92.0 ± 2.2% and 92.7 ± 3.2%, and the concentration of the recovered metal reached 19,339 ± 394 mg L-1 for potential reutilization in industrial electroplating. This research investigated a new separation strategy based on solid self-flotation for sustainable treatment of metal-laden wastewater.

4.
Chemosphere ; 296: 134033, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35183578

RESUMEN

The adsorption performances of adsorbents to dyes are hard to maintain in a wide pH range because most of the reactions are pH-dependent, developing a cost-effective strategy to break the pH-limitation is significant. In this study, an amphoteric self-floating adsorbent (Am-SA) was synthesized by hollow silica microsphere surface modification, which was useful to capture anionic acid orange 7 (AO7) and cationic crystal violet (CV) dyes, but the adsorption performances were also greatly affected by pH. Fortunately, a co-precipitation phenomenon was noticed when the AO7 and CV solutions were mixed with a 1:1 molecule ratio. The precise structures of AO7 and CV molecules were constructed and the AO7-CV-H2O mixed system was structured by Materials Studio. Besides, this system was involved in a dynamic simulation to reveal the mechanism of the co-precipitation phenomenon. The simulation results showed H2O molecules dispersed out of the system via thermal motions within 30 ps, but the AO7 and CV molecules aggregated to each other via electrostatic attractions. The energy calculations also demonstrated the electrostatic attraction between AO7 and CV is the dominant factor that induced the aggregation. The aggregation phenomena were also observed in various mixed cationic-anionic dyes systems. The removals of dyes significantly improved in a wide pH range in the mixed systems as the captures of the aggregated dye clusters were much easier than that of independent dye molecules, and both co-precipitation and adsorption contributed to it. Proper utilization of the aggregation behaviors between dyes can be regarded as a prospective strategy in cost-effective treatments.


Asunto(s)
Colorantes , Contaminantes Químicos del Agua , Adsorción , Aniones , Colorantes/química , Violeta de Genciana , Estudios Prospectivos , Contaminantes Químicos del Agua/análisis
5.
J Hazard Mater ; 423(Pt A): 126917, 2022 02 05.
Artículo en Inglés | MEDLINE | ID: mdl-34464865

RESUMEN

The ubiquitous present antibiotics in aquatic environment is attracting increasing concern due to the dual problems of bioaccumulation toxicity and antibiotic resistance. In this study, a low-cost chitin-biocalcium (CC) composite was developed by a facile alkali activation process from shell waste for typical antibiotics ciprofloxacin (CIP) removal. Response surface methodology (RSM) was utilized to optimize synthesis methodology. The optimized CC products featured superior CIP removal capacity of 2432 mg/g at 25 °C (adsorption combined with flocculation), rapid adsorption kinetics, high removal efficiency (95.58%) and wide pH adaptability (under pH range 4.0-10.0). The functional groups in chitin and high content of biocalcium (Ca2+) endowed CC abundant active sites. The kinetic experimental data was fitted well by pseudo-second-order and intraparticle diffusion model at different concentrations, revealing the removal was controlled by chemisorption and mass transport step. From the macroscopic aspect, flocs were produced with the increase of CIP concentration during the reaction, adsorption combined with flocculation were related to the CIP removal. From the microcosmic aspect, the superior removal performance was attributed to cation bridging, cation complexation among biocalcium-CIP and hydrogen bond between functional groups of chitin and CIP.


Asunto(s)
Ciprofloxacina , Contaminantes Químicos del Agua , Adsorción , Antibacterianos , Quitina , Ciprofloxacina/análisis , Floculación , Concentración de Iones de Hidrógeno , Cinética , Contaminantes Químicos del Agua/análisis
6.
Acta Crystallogr C Struct Chem ; 77(Pt 12): 782-789, 2021 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-34864721

RESUMEN

Hydrothermal reaction of Mn2+ with the ditopic ligand 2,5-bis(1H-1,2,4-triazol-1-yl)benzoic acid (Hdtba) resulted in the complex poly[aqua[µ3-2,5-bis(1H-1,2,4-triazol-1-yl)benzoato-κ3N4:N4':O]chloridomanganese(II)] monohydrate], {[Mn(C11H7N6O2)Cl(H2O)]·H2O}n, (I). Coordination polymer I has been characterized by X-ray diffraction, IR spectroscopy, elemental analysis, thermogravimetry and susceptibility measurements. The topology of I corresponds to a three-dimensional (3,6)-conn net linked by {Mn2Cl2(COO)2} building blocks and dtba- anions. Significant antiferromagnetic exchange is observed within the dinuclear {Mn2Cl2(COO)2} subunits. A fit of the susceptibility data resulted in the magnetic parameters g = 1.93 and J = -1.52. Studies of the photoluminescence properties revealed that I represents a promising luminescence sensor for sensitively detecting dichromate ions in aqueous solution. The associated photochemical detection mechanism was studied in detail.

7.
Chemosphere ; 284: 131306, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34225128

RESUMEN

In this work, the novel hollow mesoporous coagulant was prepared by chitosan-polydopamine coating and permanganate loading into silica nanoparticles for investigating the simultaneous enrichment and degradation of diclofenac sodium (DCFS) combined with ultraviolet irradiation. The enrichment kinetic of DCFS was explained well with pseudo-second-order model, indicating the exist of hydrogen bonding. Based on the correlation coefficients, the enriched isotherms were fitted by models which accorded with the BET > Freundlich > Langmuir sequence. The result showed that, in addition to the coagulant and DCFS, there were aromatic stackings among DCFS molecules. Due to both effects of which, the DCFS enrichment could be realized significantly in the range of pH 4.0-9.0. It was degraded at the copresence of ultraviolet and permanganate released from coagulant in acidic aqueous medium. The release mechanism was simulated through Korsmayer-Peppas model, implying case-II transport and Fickian diffusion. Additionally, Mn (V) and •OH radicals were vital in the DCFS degradation process. The coagulant could be reloaded at least ten times and that from each cycle was used directly for DCFS removal for six times without rinse process, which provided a potential application in environmental remediation.


Asunto(s)
Diclofenaco , Dióxido de Silicio , Compuestos de Manganeso , Óxidos
8.
J Hazard Mater ; 405: 124195, 2021 03 05.
Artículo en Inglés | MEDLINE | ID: mdl-33535359

RESUMEN

Separating and recovering lead from heavy metal contaminated wastewater is crucial for the environment remediation and reutilization of lead resources. Herein, a novel adsorbent, the phosphorylated chitosan-coated magnetic silica nanoparticles (Fe3O4@SiO2@CS-P), was successfully fabricated and applied to highly selective adsorption of lead. Competitive experiments were conducted in a multi-ion solution (7 metal ions coexist) at pH 6.0, Fe3O4@SiO2@CS-P exhibited an excellent selectively for capturing lead with the distribution coefficient (0.75 L g-1) more ten times than other metal, while Fe3O4@SiO2@CS demonstrated a highly selective adsorption of silver. These implied that phosphorylation of adsorbent not only improves the sorption performance of lead, but also changes the selective adsorption of metal types. Acidity experiments can draw conclusions that Fe3O4@SiO2@CS-P exhibited better acid resistance (with barely any iron leaching) than silica-uncoated adsorbent (Fe3O4@CS-P) at pH 1.0. Furthermore, the FTIR and XPS spectra after adsorption suggested that the high adsorption performance and selective capture lead were predominantly controlled by the coordination of the phosphate groups on the surface of the adsorbent. This work shows a broad prospect of developing a series of novel, acid-resistant, good reusable and rapidly separable magnetic materials that can be used to efficiently and selectively capture lead from aqueous solutions.

9.
J Craniofac Surg ; 32(1): 215-217, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-32833842

RESUMEN

ABSTRACT: Spread of cerebral spinal fluid (CSF) into the brain parenchyma is a very rare complication of Ommaya reservoir placement and can take form of CSF edema or an intraparenchymal pericatheter cyst. Herein, we described an extremely rare case of a progressive enlarging intraparenchymal pericatheter cyst and CSF edema in a patient with cerebral cysticercosis following Ommaya reservoir placement. A heightened index of suspicion of this rare complication is required to prevent misdiagnosis as a tumor or brain abscess that may lead to unnecessary surgical explorations.


Asunto(s)
Quistes/diagnóstico por imagen , Edema/diagnóstico por imagen , Enfermedades de la Columna Vertebral/terapia , Quistes/cirugía , Edema/cirugía , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Imagen Multimodal , Tomografía Computarizada por Rayos X
10.
J Hazard Mater ; 384: 121262, 2020 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-31586922

RESUMEN

In the case of a sharp increase in the price of dyes, the dyes concentration of in wastewater is important for environmental protection and industrial costs reduction. In this study, we grafted single-layer amino groups onto the surface of the hollow glass microspheres by a two-step simple synthesis, and the anionic dyes adsorption process reaches equilibrium within 10 min. The as-synthesized adsorbent has self-floating ability to achieve high-efficiency surface solid-liquid separation with water. SEM, EDS, SBET, FT-IR, XPS, TGA characterizations results demonstrated the successful grafting of amino groups and the important role of the pretreatment process in the two-step synthesis. The results of adsorption isotherms and kinetics show the adsorption process belongs to single-layer adsorption with equal adsorption sites, and the adsorption capacities for acid orange 7 and amaranth reach 428.99 mg g-1 and 145.62 mg g-1, respectively. Regeneration of the adsorbent and concentration of the dye solutions can be achieved by dispersing the separated adsorbent in alkaline solution, the maximum concentrated concentration of acid orange 7 and amaranth was 6321.57 mg L-1 and 2431.84 mg L-1, respectively. This study provides new insights for the solid-liquid separation of water treatment agents and the resource regenerating of dyeing wastewater.

11.
J Hazard Mater ; 381: 120971, 2020 01 05.
Artículo en Inglés | MEDLINE | ID: mdl-31421555

RESUMEN

Rapid, high-efficient adsorbents with efficient solid-liquid separation ability has broad application prospects in the treatment of dye wastewater. In this study, polydopamine and methacryloyloxyethyltrimethyl ammonium chloride were grafted onto hollow glass microspheres to prepare the enhanced polydopamine shell structure adsorbent with self-floating ability. Furthermore, the adsorbent achieves high-efficiency surface solid-liquid separation, which overcomes the disadvantages of the traditional separation methods. Characterizations of the as-synthesized microspheres were performed using various techniques such as SEM, EDS, BET, XPS, FT-IR, TGA and XRD. The adsorbent achieved rapid and high-efficient adsorption of alizarin cyanine green F via the interactions of electrostatic attracting and π-π stacking, and under the optimal experimental conditions, the removal efficiency of 0.10 m mol L-1 dye solution reaches 94.51%, and the adsorption process reaches equilibrium within 60 min. Adsorption isotherms and kinetics data of the adsorbent were well fitted by Langmuir isotherm and pseudo-second-order kinetic models, respectively. The as-synthesized adsorbent has excellent recyclability, and its adsorption performance can be maintained after 5 cycles of reuse. The self-floating adsorbent has great potential for the removal of dissolved contaminants and cost-effective separation.

12.
Acta Crystallogr C Struct Chem ; 75(Pt 9): 1286-1298, 2019 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-31484818

RESUMEN

Coordination polymers (CPs) with specific structures and functional luminescence have been widely designed as sensors for detecting small molecules and ions. In this study, with or without the help of an N-donor auxiliary linker, three new ZnII CPs, namely, three-dimensional (3D) poly[[pentaaquabis[µ3-5-(4-carboxybenzyloxy)isophthalato]bis[µ6-5-(4-carboxylatobenzyloxy)isophthalato]di-µ3-hydroxido-hexazinc(II)] trihydrate], {[Zn6(C16H10O7)2(C16H9O7)2(OH)2(H2O)5]·3H2O}n or {[Zn6(µ3-HL)2(µ6-L)2(µ3-OH)2(H2O)5]·3H2O}n, (I), one-dimensional (1D) catena-poly[[[aqua(1,10-phenanthroline)zinc(II)]-µ2-5-(4-carboxybenzyloxy)isophthalato] dihydrate], {[Zn(C16H10O7)(C12H8N2)(H2O)]·2H2O}n or {[Zn(µ2-HL)(phen)(H2O)]·2H2O}n (phen is 1,10-phenanthroline), (II), and 3D poly[diaquatetrakis(4,4'-bipyridine)bis[µ6-5-(4-carboxylatobenzyloxy)isophthalato]di-µ3-formato-di-µ3-hydroxido-pentazinc(II)], [Zn5(C16H9O7)2(HCOO)2(OH)2(C10H8N2)4(H2O)2]n or [Zn5(µ4-L)2(bpy)4(µ2-OH)2(µ3-HCOO)2(H2O)2]n (bpy is 4,4'-bipyridine), (III), have been constructed from the semi-rigid tricarboxylic acid 5-(4-carboxybenzyloxy)isophthalic acid (H3L) under hydrothermal conditions. CP (I) exhibits a twofold interpenetrated 3D+3D→3D skeleton with a 3,5-conn topology constructed from triangular trinuclear [Zn3(COO)4(µ3-OH)] clusters, in which the H3L ligand adopts three different coordination modes. CP (II) exhibits a 1D infinite chain and stacking that gives a 3D structure mediated by hydrogen bonds and weak interactions. CP (III) is an interesting 3D 3,4,8-conn network including linear tetranuclear [Zn4(µ2-OH)2(HCOO)2(COO)2] clusters with a new {4·62}2{4·64·8}{46·619·83} topological symbol. The influences of the flexible -CH2-O- linker of the H3L ligand and subtle environmental factors, such as solvent, pH value and auxiliary ligands, on the formation of the final structures are also discussed. The solid-state fluorescence spectra of CPs (I)-(III) were recorded at room temperature and all show better fluorescence performances than H3L. In particular, (II) can act as a potential multifunctional fluorescent material for sensing hexavalent chromium ions in aqueous solution with high stability, selectivity and sensitivity. Under ultraviolet light of 365 nm from a UV lamp, a signal response of fluorescence from turning on to off can be observed with the naked eye. It was found that the detection for hexavalent chromium (i.e. Cr2O72-) by (II) has a high selectivity [KSV = 1.61 × 104 M-1 and limit of detection (LOD) = 0.434 µM] in aqueous solution. Quenching mechanisms were also studied in detail.

13.
J Hazard Mater ; 375: 138-148, 2019 08 05.
Artículo en Inglés | MEDLINE | ID: mdl-31054531

RESUMEN

In this study, our group grafted 2-acrylamido-2-methylpropane sulfonic acid (AMPS) onto the surface of hollow glass microspheres (HGM) and successfully prepared AMPS grafted floating adsorbent (AFA). The prepared AFA carries a large amount of negative charges, and the adsorptions of cationic dyes are achieved under the action of strong electrostatic interaction. Furthermore, due to the unique shell structure of AFA, it has a stable self-floating ability, which may change the traditional separation method to make the adsorbent easier to enrich and separate from water surface. Characterizations of AFA by scanning electron microscope, energy dispersive spectrometry, X-ray photoelectron spectroscopy. Fourier transform infrared spectra, Brunauer-Emmett-Teller surface areas, thermogravimetric analysis, and X-ray diffractometer shows the successful grafting of AMPS. Adsorption experiments confirmed that the adsorption capacities of AFA for methylene blue, malachite green, basic fuchsin and crystal violet under optimum conditions were 436.8 mg g-1, 637.6 mg g-1, 457.8 mg g-1, and 399.4 mg g-1, respectively. At the same time, AFA has excellent recyclability, and its adsorption capacity can be maintained after 6 cycles of reuse.

14.
J Hazard Mater ; 367: 492-503, 2019 04 05.
Artículo en Inglés | MEDLINE | ID: mdl-30620925

RESUMEN

In this study, modified magnetic chitosan microparticles (MCDs) were fabricated and used as adsorbents for the removal of Food Yellow 3 (FY3) and Acid Yellow 23 (AY23) from aqueous solution. The magnetic microparticles were characterized by scanning electronic microscope, Brunauer-Emmett-Teller specific surface area, elemental analysis, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, thermogravimetry analysis, differential scanning calorimetry, and vibrating-sample magnetometer. Then, the effects of pH value, initial dye concentration, and contact time on the adsorption of FY3 and AY23 by MCDs were investigated. Evidently, MCDs showed excellent adsorption performance for both food dyes, and their adsorption capacities (833.33 mg/g for FY3 and 666.67 mg/g for AY23) were considerably higher than those of unmodified adsorbents, which could be attributed to the electrostatic interaction and ion exchange between the grafted cationic polymer and food dyes. Adsorption isotherm and kinetic data of the magnetic microparticles were well fitted by Langmuir isotherm and pseudo-second-order kinetic model, respectively. The regeneration and reusability of MCDs were also explored. Results showed that more than 80% adsorption capacities of MCDs for FY3 and AY23 remained after five adsorption-desorption cycles.


Asunto(s)
Quitosano/química , Colorantes de Alimentos/química , Contaminantes Químicos del Agua/química , Adsorción , Concentración de Iones de Hidrógeno , Fenómenos Magnéticos , Eliminación de Residuos Líquidos , Purificación del Agua
15.
Sci Total Environ ; 640-641: 107-115, 2018 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-29859427

RESUMEN

Due to the complexity of contaminants, the effectiveness of traditional flocculants toward water purification is insufficient. To break the limitation, a novel polymer flocculant [chitosan grafted poly (acrylamide-itaconic acid), CS-g-P(AM-IA)] was synthesized via ultraviolet-initiated graft copolymerization reaction. Characterization results revealed that the graft copolymers were successfully synthesized and with rougher surface structure. The solubility of CS-g-P(AM-IA) and chitosan grafted polyacrylamide (CS-g-PAM) were greatly improved and they can dissolve in the wide pH range of 2.0-12.0. CaCl2 was used as a source of cation bridge to enhance the flocculation of kaolin particles, and its optimum dosage was 150 mg·L-1. At dosage of 30 mg·L-1 and pH of 5.0, the turbidity removal efficiency of CS-g-P(AM-IA) reached the maximum of 93.8%, whereas those of CS-g-PAM and CS were 96.7% and 76.9%, respectively. The patchwise adsorption of ionic groups embedded in the molecular chain on Ca2+-clay complexes took effect to generate flocs with larger particle size. Besides, the decolorization ability of cationic dyes by CS-g-P(AM-IA) was greatly enhanced due to the role of abundant carboxyl groups. In the crystal violet (CV) adsorption experiment, the maximum CV dye removal efficiency for CS-g-P(AM-IA) reached the maximum of 81.6% at dosage of 0.7 mg·mL-1 and pH of 9.0, while those for CS-g-PAM and CS were 51.7% and 36.5%, respectively.

16.
Sci Total Environ ; 640-641: 243-254, 2018 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-29859440

RESUMEN

Graft modified flocculants have recently received increasing attention in the field of water treatment as they have the combinative advantages of synthetic and natural polymeric flocculants. In this work, surface-active monomer benzyl(methacryloyloxyethyl)dimethylammonium chloride (BMDAC) was selected to graft on dextran (DX) with high molecular weight (10.3 × 106 g/mol) produced through enzyme-catalyzed process in order to remove dissolved dyes from wastewater. The flocculant (DAB) was fabricated by ultrasound initiated polymerization technique, and the structure characterization of FTIR, 1H/12C NMR, XRD and XPS spectrum confirmed the successful grafting. Then the Congo red (CR) removal efficiency by DAB was optimized based on the flocculation conditions, including wastewater initial pH, flocculant dosage and initial dye concentration. The effect of suspended solids on the removal of dyes was evaluated in kaolin-CR simulated wastewater. The results indicated that the optimal removal efficiency of CR was 68.1% and 88.2% in single CR and kaolin-CR flocculation system, respectively. The improvement of removal efficiency was attributed to the fact that partial CR molecules were adsorbed onto kaolin particles before flocculation, and were synergistically flocculated accompanied by kaolin particles. Finally, the flocculation mechanism was discussed by a detailed investigation of the zeta potentials, FTIR and XPS spectra of flocs, which can provide important reference for optimizing the flocculation conditions and designing novel high-performance flocculants.

17.
Int J Biol Macromol ; 112: 648-655, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29421492

RESUMEN

A novel chitosan-based magnetic adsorbent [poly(2-acrylamido-2-methylpropane sulfonic acid) grafted magnetic chitosan microspheres, PMCMs] was successfully fabricated via free radical polymerization for effectively removing the cationic dye methylene blue (MB). The effects of initial solution pH (1.0-10.0), temperature (30-50°C), contact time (0-660min) and initial concentration (50-1600mg/L) were studied. The results indicated that the adsorption capacity increased with the increasing of initial solution pH and temperature. The adsorption kinetic and adsorption equilibrium data fitted closely to the pseudo-second-order kinetic model and Langmuir isotherm model respectively, confirming monolayer adsorption. The maximum adsorption capacity of PMCMs for MB at initial solution 9.0 were 1000, 1250 and 1428mg/g at 30, 40 and 50°C, respectively. Furthermore, the magnetic microspheres could be easily separated using a magnet and effectively regenerated after finishing the treatment process. Therefore, PMCMs are promising candidates for the removal of dye from wastewater.


Asunto(s)
Quitosano/química , Colorantes/aislamiento & purificación , Magnetismo , Microesferas , Polímeros/química , Ácidos Sulfónicos/química , Adsorción , Concentración de Iones de Hidrógeno , Cinética , Polímeros/síntesis química , Soluciones , Espectrometría por Rayos X , Espectroscopía Infrarroja por Transformada de Fourier , Electricidad Estática , Ácidos Sulfónicos/síntesis química , Temperatura , Termogravimetría , Difracción de Rayos X
18.
J Craniofac Surg ; 27(2): e128-30, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26845092

RESUMEN

Both of Pituitary adenoma (PA) and Rathke cleft cyst (RCC) are the most common and benign sellar lesions. Generally, the origin of RCC is considered to be derived from remnants of Rathke punch, while PA is formed by proliferation of the anterior wall of Rathke pouch. Although they have a possibility to share a common embryological origin, the coexistence of PA and RCC is extremely rare. Here, the authors report a 50-year-old male patient who was found to have a large cystic sellar lesion, and surgical resection revealed components of a RCC coexisting with a PA. This collision reminded us of the possibility of RCC coexisting with PA. Furthermore, a clinicopathologic relation of them were reviewed and investigated.


Asunto(s)
Adenoma/complicaciones , Adenoma/cirugía , Quistes del Sistema Nervioso Central/cirugía , Neoplasias Primarias Múltiples/cirugía , Neoplasias Hipofisarias/cirugía , Adenoma/diagnóstico , Adenoma/patología , Quistes del Sistema Nervioso Central/diagnóstico , Quistes del Sistema Nervioso Central/patología , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Neoplasias Primarias Múltiples/diagnóstico , Neoplasias Primarias Múltiples/patología , Hipófisis/patología , Neoplasias Hipofisarias/diagnóstico , Neoplasias Hipofisarias/patología
19.
Plant Biotechnol J ; 14(2): 592-602, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26011089

RESUMEN

Myo-inositol-1-phosphate synthase (MIPS) is a key rate limiting enzyme in myo-inositol biosynthesis. The MIPS gene has been shown to improve tolerance to abiotic stresses in several plant species. However, its role in resistance to biotic stresses has not been reported. In this study, we found that expression of the sweet potato IbMIPS1 gene was induced by NaCl, polyethylene glycol (PEG), abscisic acid (ABA) and stem nematodes. Its overexpression significantly enhanced stem nematode resistance as well as salt and drought tolerance in transgenic sweet potato under field conditions. Transcriptome and real-time quantitative PCR analyses showed that overexpression of IbMIPS1 up-regulated the genes involved in inositol biosynthesis, phosphatidylinositol (PI) and ABA signalling pathways, stress responses, photosynthesis and ROS-scavenging system under salt, drought and stem nematode stresses. Inositol, inositol-1,4,5-trisphosphate (IP3 ), phosphatidic acid (PA), Ca(2+) , ABA, K(+) , proline and trehalose content was significantly increased, whereas malonaldehyde (MDA), Na(+) and H2 O2 content was significantly decreased in the transgenic plants under salt and drought stresses. After stem nematode infection, the significant increase of inositol, IP3 , PA, Ca(2+) , ABA, callose and lignin content and significant reduction of MDA content were found, and a rapid increase of H2 O2 levels was observed, peaked at 1 to 2 days and thereafter declined in the transgenic plants. This study indicates that the IbMIPS1 gene has the potential to be used to improve the resistance to biotic and abiotic stresses in plants.


Asunto(s)
Adaptación Fisiológica , Sequías , Ipomoea batatas/enzimología , Mio-Inositol-1-Fosfato Sintasa/genética , Nematodos/fisiología , Tallos de la Planta/parasitología , Tolerancia a la Sal/efectos de los fármacos , Cloruro de Sodio/farmacología , Ácido Abscísico/farmacología , Adaptación Fisiológica/efectos de los fármacos , Adaptación Fisiológica/genética , Animales , Resistencia a la Enfermedad/efectos de los fármacos , Genes de Plantas , Ipomoea batatas/genética , Ipomoea batatas/parasitología , Ipomoea batatas/fisiología , Mio-Inositol-1-Fosfato Sintasa/metabolismo , Nematodos/efectos de los fármacos , Enfermedades de las Plantas/parasitología , Tallos de la Planta/efectos de los fármacos , Plantas Modificadas Genéticamente , Polietilenglicoles/farmacología , Tolerancia a la Sal/genética , Transducción de Señal/efectos de los fármacos , Estrés Fisiológico/efectos de los fármacos , Regulación hacia Arriba/efectos de los fármacos , Regulación hacia Arriba/genética
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