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1.
Int Wound J ; 21(3): e14462, 2023 Nov 06.
Artículo en Inglés | MEDLINE | ID: mdl-37931597

RESUMEN

Ultrasound (US) has traditionally been recognised for its imaging capabilities, but its emerging role as a therapeutic modality in postoperative wound management, especially in paediatric care, has garnered significant attention. This meta-analysis aimed to evaluate the influence of US on postoperative wound healing and infection rates in paediatric patients. From an initial pool of 1236 articles, seven were deemed suitable for inclusion. Postoperative wound healing was assessed using the Redness, Edema, Ecchymosis, Discharge, and Approximation (REEDA) scale. Notably, there was a significant difference in wound healing patterns between the US-treated and control groups (I2 = 94%, standardized mean difference [SMD]: -4.60, 95% confidence intervals [CIs]: -6.32 to -2.88, p < 0.01), as illustrated in Figure 4. Additionally, a marked difference in wound infection rates was observed between the groups (I2 = 93%, SMD: -5.86, 95% CIs: -9.04 to -2.68, p < 0.01), as portrayed in Figure 5. The findings underscore the potential benefits of US in enhancing postoperative wound healing and reducing infection rates in paediatric surgical settings. However, the application of US should be judicious, considering the nuances of individual patient needs and clinical contexts.

2.
Front Pediatr ; 11: 1189373, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37780047

RESUMEN

Objectives: We aimed to investigate the association between right ventricular longitudinal strain measured by two-dimensional speckle-tracking echocardiography (2D-STE) and right heart catheterization data in pediatric patients with pulmonary hypertension (PH). Methods: Two groups were evaluated, each consisting of 58 patients. Group 1, patients with PH; Group 2, normal matched controls. Data were collected from 58 patients with PH who underwent invasive hemodynamic evaluation. Standard transthoracic echocardiographic assessment was performed in all patients under the same circumstances. All patients underwent 2D-STE, and off-line analysis generated right ventricle longitudinal strain (RVLS) and right ventricular free wall strain (RVFW) and collected echocardiographic conventional parameters of right ventricular function, including the control group. The relationship between invasive characteristics and right ventricular function parameters was analyzed. Results: In all, 58 PH patients were included in our study. The mean pulmonary artery pressure (mPAP) and pulmonary vascular resistance (PVR) were strongly correlated with right ventricular free wall strain (RVFW) and right ventricular longitudinal strain (RVLS), moderately correlated with the right ventricle myocardial performance index (Tei index), weakly correlated with the transverse diameter of the right ventricle (RV) and the transverse diameter of the right atrium (RA), and moderately negatively correlated with right ventricular fractional area change (RVFAC). In terms of segments of the right ventricular free wall, the basal segment had the highest correlation coefficient with mPAP and PVR (r = 0.413, 0.523, 0.578, r = 0.421, 0.533, 0.575, p < 0.05, respectively). Tricuspid annular plane systolic excursion (TAPSE), main pulmonary artery diameter (MPA), peak systolic velocity of the right ventricle (RV-S'), and RA area parameters were not associated with mPAP and PVR (p > 0.05). Conclusions: Right ventricular longitudinal strain is a reliable indicator to evaluate right ventricular function in pediatric patients with PH. It can provide valuable reference information for the clinical judgment of the status and severity of the disease in children.

3.
BMC Cardiovasc Disord ; 23(1): 409, 2023 08 18.
Artículo en Inglés | MEDLINE | ID: mdl-37596522

RESUMEN

PURPOSE: Left bundle branch block (LBBB) has been confirmed to be independently associated with adverse outcomes in dilated cardiomyopathy (DCM). However, prognostic data on nonspecific intraventricular conduction delay (NSIVCD) are still limited and conflicting. We aimed to evaluate the prognosis of DCM with NSIVCD. METHODS: A total of 548 DCM patients who underwent cardiovascular magnetic resonance imaging (CMR) from January 2016 to December 2017 were consecutively enrolled. The cohort was divided into four groups: 87 with LBBB, 27 with RBBB, 61 with NSIVCD, and 373 without intraventricular conduction delay (IVCD). After a median follow-up of 58 months (interquartile range: 47-65), 123 patients reached the composite endpoints, which included cardiovascular death, heart transplantation, and malignant arrhythmias. The associations between different patterns of IVCD and the outcomes of DCM were analysed by Kaplan‒Meier analysis and Cox proportional hazards regression analysis. RESULTS: Of 548 DCM patients, there were 398 males (72.6%), and the average age was 46 ± 15 years, ranging from 18 to 76 years. In Kaplan‒Meier analysis, patients with NSIVCD and LBBB showed higher event rates than patients without IVCD, while RBBB patients did not. By multivariate Cox regression analysis, LBBB, NSIVCD, NYHA class, left ventricular ejection fraction (LVEF), indexed left ventricular end-diastolic diameter (LVEDDI), percentage of late gadolinium enhancement mass (LGE%), and global longitudinal strain (GLS) were found to be independently associated with the outcomes of DCM. CONCLUSIONS: In addition to LBBB, NSIVCD was an unfavourable prognostic marker in patients with DCM, independent of LVEDDI, NYHA class, LVEF, LGE%, and GLS.


Asunto(s)
Bloqueo de Rama , Cardiomiopatía Dilatada , Adolescente , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven , Bloqueo de Rama/diagnóstico por imagen , Cardiomiopatía Dilatada/diagnóstico por imagen , Cardiomiopatía Dilatada/terapia , Imagen por Resonancia Magnética , Pronóstico , Estudios Retrospectivos
4.
Materials (Basel) ; 16(15)2023 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-37569909

RESUMEN

The forging-healing of the internal porosity defects affects the tensile, impact and fatigue properties of heavy forgings. In the present work, the effect of deformation process on the microstructure in the joint area as well as the tensile strength, impact toughness and fatigue strength was studied experimentally. It is shown that the tensile strength is restored once the porosity defects were healed, and the impact toughness is recovered when the flat grain band is eliminated. The fatigue strength can be restored if a uniform grain structure can be achieved in both the joint area and the matrix, whereafter precipitate become the key factor affecting the fatigue strength. A complete healing of the porosity defects, a uniform grain structure in the joint area and the matrix, and a fully controlled precipitate are essential to guarantee the mechanical properties and in-service performance of the heavy forgings.

5.
J Neurosci Res ; 101(7): 1107-1124, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-36929608

RESUMEN

Oxidative damage and cell death are involved in the pathogenesis of hypoxic-ischemic brain damage (HIBD). Ferroptosis is a newly identified mode of cell death that results from the oxidative damage induced by excessive iron. In HIBD, iron accumulates in brain tissues due to the massive destruction of red blood cells and increased permeability of the blood brain barrier vasculature, which can trigger ferroptosis. Ferroptosis is implicated in various diseases involving neuronal injury; however, the roles of iron and ferroptosis in HIBD have not been identified. In the present study, we investigated the role of iron overload in neuronal ferroptosis both in HIBD rat models and in oxygen- and glucose-deprived (OGD) SH-SY5Y cells. We observed that iron deposition in the cerebral cortex was significantly increased in HIBD rats. Features of ferroptosis such as shrunken mitochondria, increased MDA (malondialdehyde) levels, and reduced solute carrier family 7 member 11 (SLC7A11) and glutathione peroxidase 4 (GPX4) expression were observed in the cerebral cortex of HIBD rats. Administration of an iron chelator in HIBD rats upregulated SLC7A11 expression and alleviated neuronal ferroptosis in cerebral cortex tissue. Additionally, overexpression of SLC7A11 in SH-SY5Y cells increased cell viability and attenuated OGD-induced ferroptosis. Our results demonstrate that iron overload induces neuronal ferroptosis by inhibiting SLC7A11 expression in HIBD. Inhibition of neuronal ferroptosis may be a promising strategy to alleviate brain damage in HIBD.


Asunto(s)
Ferroptosis , Hipoxia-Isquemia Encefálica , Sobrecarga de Hierro , Neuroblastoma , Animales , Humanos , Ratas , Sistema de Transporte de Aminoácidos y+/metabolismo , Barrera Hematoencefálica/metabolismo , Hierro/metabolismo
6.
J Environ Manage ; 326(Pt A): 116660, 2023 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-36375433

RESUMEN

Chemical immobilisation is extensively used for in-situ remediation of heavy metals contaminated soil. Immobilised heavy metals could be reactivated by multiple factors such as pH, moisture, temperature, rainfall, etc., among which rainfall is very important, especially acid rain in southern China. Wet-dry alternations were used to simulate the leaching of metals by rainwater. The variation of cadmium (Cd) and zinc (Zn) speciation distribution in soil immobilised with iron oxides (goethite (GE) and 2-line ferrihydrite (GLS)) was investigated. The impacts of wet-dry alternations on the properties of the soil and amendments were also assessed. In the soil without amendments (OS) and amended with GE (GS), the stable fractions were reactivated and transformed into labile fractions under wet-dry alternations. In the soil amended with GLS (LS), the exchangeable and carbonate-bound Cd decreased while the soluble, Fe-Mn oxide bound and organic bound Cd increased. The carbonate-bound Zn was transformed into the Fe-Mn oxide-bound Zn. Transformation from the amorphous iron oxide into crystalline iron oxide in GS and LS were 4.9% and 5.3%. The Pearson correlation analysis showed that the soil pH and the iron-oxide speciation were strongly correlated with Cd/Zn fractions in the soil. The specific surface area, pore volume and adsorption capacity of the iron oxides decreased by 9.26%, 38.89% and 62-73% (for GE), 1.88%, 22.22% and 26-55% (for GLS). The altered soil properties and morphological differences between the two iron oxides under wet-dry alternations were important reasons for Cd/Zn reactivation.


Asunto(s)
Metales Pesados , Contaminantes del Suelo , Cadmio/química , Suelo/química , Zinc/química , Contaminantes del Suelo/análisis , Metales Pesados/química , Óxidos/química , Hierro/química
7.
Chemosphere ; 307(Pt 3): 135853, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-35948099

RESUMEN

Iron oxide-lignin composites (GLS) were prepared based on the significant role of Fe-OM in the environmental behaviour of heavy metals and lignin binding with iron oxide preferentially in soil. GLS was applied in Cd/Pb immobilization and the stability under acid rain was investigated. The results show that the iron oxide appeared weakly crystalline or amorphous similar to 2-line ferrihydrite after the addition of lignin. Agglomerates of nanoparticles with higher adsorption capacity were observed for GLS. The mobility factor (MF) of Cd/Pb in the soil decreased rapidly after adding GLS. At the 3% dosage, the MF of Cd and Pb in the soil was decreased by 58.94% and 78.15% respectively, which was approximately 5 times that of goethite (GE). The mobile and exchangeable Cd/Pb were converted to organic, amorphous Fe oxide-bound and residue fractions. Under acid rain conditions, MF continues to decline for the GLS group, increasing the organic and amorphous Fe oxide-bound fractions, while for control group (CK) and GE, the trend was the opposite. Lignin could inhibit iron oxide dissolution and stabilize the combination of Cd/Pb and iron oxides in soil. The better stability performance of GLS for Cd/Pb may be related to the higher adsorption capacity and microstructural difference after iron oxide combined with lignin.


Asunto(s)
Lluvia Ácida , Restauración y Remediación Ambiental , Metales Pesados , Contaminantes del Suelo , Cadmio/análisis , Compuestos Férricos , Hierro , Compuestos de Hierro , Plomo , Lignina , Metales Pesados/análisis , Minerales , Óxidos/química , Suelo/química , Contaminantes del Suelo/análisis
8.
RSC Adv ; 12(5): 3062-3072, 2022 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-35425338

RESUMEN

Low-rank coal, such as Shengli lignite (SL) and Datong bitumite (DT), has abundant reserves and is low in cost. Due to its high moisture content, abundant oxygen-containing groups, high ash content and low calorific value, low-rank coal is mainly used in a low-cost method of direct combustion. For better value-added utilization of SL and DT, a novel strategy has been developed for the preparation of oxygen-rich hierarchical porous carbons (HPCs) by hydrothermal carbonization (HTC), followed by steam activation. In this paper, firstly, the physical and chemical properties of SL and DT were improved by HTC pretreatment, bringing them closer to high rank coal. Then, the effects of HTC pretreatment and activation temperature on the properties of the HPCs were investigated in detail. The results show that the HPCs have mainly microporous structures (the microporosity of 200-SLHPC-900 is 79.58%) based on the N2 adsorption-desorption isotherm analysis and exhibit a higher specific surface area (SSA) and larger pore volume (25.02% and 2.69% improvement for 200-SLHPC-900; 4.93% and 14.25% increase for 200-DTHPC-900, respectively) after HTC pretreatment. The two types of HPCs also present good adsorption performance. The iodine adsorption value of lignite-based HPC presents an increase of 13.72% from 503 mg g-1 to 572 mg g-1, while the value of bitumite-based HPC increases up to 924 mg g-1. A preliminary additional HTC step is therefore an effective method by which to promote the performance of low-rank coal based porous carbon. The process of hydrothermal carbonization and steam activation is a cost-effective and environmentally-friendly preparation method, which omits the use of a chemical activator and reduces the step of alkaline waste liquid discharge compared with the route of carbonization and chemical activation.

9.
Sci Total Environ ; 802: 149922, 2022 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-34525730

RESUMEN

Iron oxide is a natural mineral that generally exists in the form of iron oxide-organic complexes (Fe-OM) in soil. Lignin is a naturally occurring polymer that is considered to be an important part of soil carbon cycling. In this study we prepared a composite material (MGE) with iron oxide and lignin based on the Fe-OM present in the soil. MGE was then applied to remediate Cd and Pb in contaminated soil. The results show that DTPA-Cd and DTPA-Pb levels were reduced by 58.87% and 78.09%, respectively. The bacterial community diversity index decreased in the iron oxide (GE) group, but a slight increase was observed in the MGE group. In terms of species composition in the MGE group, the abundance of Proteobacteria, Gemmatimonadota and Acidobacteriota increased, while the abundance of Bacteroidota, Actinobacteriota and Firmicutes decreased. The outcome in the GE group was the opposite. In the MGE group, HCl-Fe2+, HCl-Fe3+, and pH were significantly higher than in the other groups, indicating that MGE stimulated the growth of iron-reducing bacteria (FeRB) and promoted iron redox reactions. Iron oxide could be reduced to Fe2+ due to the activity of FeRB, and then Fe2+ would be oxidised and hydrolysed, which led to an increase in soil pH. Secondary minerals were formed during this process. With the oxidation of Fe2+ and the formation of secondary minerals, Cd and Pb could be stabilised in the oxides and were not easily released through a co-precipitation mechanism.


Asunto(s)
Contaminantes del Suelo , Suelo , Bacterias , Cadmio/análisis , Compuestos Férricos , Plomo , Lignina , Contaminantes del Suelo/análisis
10.
Sci Total Environ ; 738: 139952, 2020 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-32534277

RESUMEN

Lignin is a precursor of humus in soil and sediment. Lignin can be separated from vascular plants in the form of lignosulfonate via pulping processes. On the other hand, composites of iron oxide and organic matter can adsorb heavy metals, and thus influence the migration of these heavy metals in the environment. In this paper, a hematite/lignosulfonate composite (HLS) was prepared via coprecipitation to compare the adsorption performance of hematite (α-Fe2O3) toward Cd(II) before and after the incorporation of lignosulfonate (LS). The HLS is found to exhibit a weakly crystalline structure and possess a large number of nanoscale particles. Specific surface area of HLS (291.97 m2/g) is about 11 times that of α-Fe2O3, and the pore volume of HLS (0.22 cm3/g) is twice that of α-Fe2O3. The adsorption of Cd(II) is well illustrated by the pseudo-second-order adsorption kinetics and the initial adsorption rate (h) of HLS is 13.83 times that of α-Fe2O3. The maximum adsorption capacities are significantly improved from 4.89-6.35 mg/g (α-Fe2O3) to 39.03-53.65 mg/g (HLS). A greater affinity and more favorable association between Cd(II) and HLS is observed via fitting models. The incorporation of LS provides HLS with significantly better adsorption properties toward Cd(II) than α-Fe2O3, as is further confirmed by FT-IR and XPS characterization. Fe-O-O-H and Fe-O-H structures as well as more hydroxyl groups are observed, which promote the adsorption performance since the process are mainly influenced by complexation via coordination bonds.

11.
Pediatr Cardiol ; 41(1): 38-45, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31650215

RESUMEN

Although isolated congenital ventricular septal defects (VSD) can be repaired with a high degree of success, residual shunts (RS) are commonplace postoperatively. Small RS are relatively innocuous and tend to spontaneously close with time, despite the emotional burden it poses for the patient and family. A large RS, however, needs ongoing surveillance and may necessitate reintervention. Factors influencing the incidence of RS as well as the likelihood and expected timing of its spontaneous closure are discussed in this study. The patient records and relevant data of 362 consecutive patients undergoing cardiac operation with isolated congenital VSD closure as primary procedure between January 2017 and December 2017 were included in the study. Postoperative transthoracic echocardiograms were performed at hospital discharge, and during follow-up, at 1 month, 3 months, 6 months and 1 year postoperatively. Residual defects were measured under echocardiogram at every follow-up. Factors expected to be associated with RS occurrence and spontaneous closure were included for logistic and Cox regression statistical analysis. There were 113 cases where RS occurred according to the first postoperative echocardiograms that were performed at discharge, of which 80 were confirmed closed during subsequent follow-up, with a median follow-up of 96 days. A cutoff of 1.25 mm for the initial RS was found to be the best predictor of spontaneous closure at 6-month follow-up. Small shunts had higher closure rate than larger ones by a follow-up duration of 300 days, at which the two groups tended to reach a similar spontaneous closure rate. Longer surgical bypass time distinguished small from larger residual shunts measured upon discharge. Following repair of isolated congenital VSDs, the incidence of a residual shunt is high. The majority spontaneously close within 300 days following surgery. Longer bypass time predicted a larger residual shunt upon discharge. Larger than 1.25 mm shunts had lower short-term closure rate but seemed not to differ from smaller shunts beyond 300 days postoperatively.


Asunto(s)
Procedimientos Quirúrgicos Cardíacos/efectos adversos , Defectos del Tabique Interventricular/cirugía , Complicaciones Posoperatorias/terapia , Procedimientos Quirúrgicos Cardíacos/métodos , Ecocardiografía , Femenino , Estudios de Seguimiento , Humanos , Lactante , Masculino , Periodo Posoperatorio , Factores de Riesgo
12.
Huan Jing Ke Xue ; 40(12): 5623-5628, 2019 Dec 08.
Artículo en Chino | MEDLINE | ID: mdl-31854635

RESUMEN

The Pearl River Delta region is the major economic zone of the Greater Bay Area:it presents a large number of industrial-mining enterprises and is interested by severe heavy metal pollution (mainly caused by Pb and Cd). The research and development of safe and efficient heavy metal remediation materials and technologies is fundamental in order to guarantee regional environmental quality and habitat safety. Goethite-fulvic acid composites were prepared using goethite minerals present in the red soils of the Pearl River Delta region by passivation repair, and were applied to immobilize Pb and Cd in a co-contaminated soil. The results showed that a higher ratio of fulvic acid in the composites enhanced the immobilization effect on Pb and Cd:the immobilization efficiency (IE) of Pb and Cd increased with the passivation time, and then stabilized. Additionally, the exchangeable and carbonate-bound fractions of Pb and Cd in the soil decreased, while the Fe-Mn oxide-bound and residual fractions increased. The cation exchange capacity (CEC), as well as the available K and NH4+-N in the soil increased after the application of the composite materials. We conclude that goethite-fulvic acid composites can be effectively applied to the remediation of Pb-Cd contaminated soil.

13.
Environ Toxicol Chem ; 38(5): 1132-1141, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30821838

RESUMEN

Phthalic acid esters (PAEs) represent an ongoing pollution problem and have attracted extensive attention due to their ubiquitous presence in the environment. We investigated the distribution of 6 PAEs (benzyl butyl phthalate [BBP], dibutyl phthalate [DBP], di-(2-ethylhexyl) phthalate [DEHP], diethyl phthalate [DEP], dimethyl phthalate [DMP], and di-n-octyl phthalate [DnOP]) in cultivated soils, including vegetable fields and paddy fields, as well as the soils of E-waste dismantling sites. We also explored the relationship between the particle size of soils and the distribution of PAEs, put forward a novel method to forecast the occurrence and fate of PAEs in soils with DEHP used as a chemical indicator, and made a preliminary assessment of the potential ecological risks of the 6 target compounds in soils. The results showed that the detection rate of target PAEs was 100%, and that the concentrations of ∑6 PAEs ranged from 1.2 to 7.3 mg/kg in vegetable fields, 1.2 to 1.5 mg/kg in paddy fields, and 11.8 to 17.9 mg/kg in E-waste dismantling sites. In addition, DEHP exhibited the maximum concentrations (0.480-15.34 mg/kg) in all soil samples. The results also showed that in the wake of decreasing particle size, increasing soil organic carbon would enhance the sorption of PAEs in soils. Moreover, the correlation formula of DEHP successfully predicted the concentrations of other PAEs and ∑ 6 PAEs in soils, suggesting that DEHP could be a dependable chemical indicator for forecasting the environmental occurrence of PAEs in soils. Based on the residual levels in the trial sites and limited toxicity data, high risks to soil organisms are expected for DBP, DEP, and DEHP, and low-medium risks for BBP, DnOP, and DMP. Environ Toxicol Chem 2019;00:1-11. © 2019 SETAC.


Asunto(s)
Agricultura , Dietilhexil Ftalato/análisis , Residuos Electrónicos , Ésteres/análisis , Ácidos Ftálicos/análisis , Carbono/análisis , China , Geografía , Tamaño de la Partícula , Medición de Riesgo , Suelo/química , Contaminantes del Suelo/análisis
14.
Chemosphere ; 222: 556-563, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-30721815

RESUMEN

The coprecipitation of organic matter (OM) and minerals is a relatively common phenomenon in soil, and it has a significant influence on the surface properties and reactivity of minerals. In turn, the fate of pollutants in soil is greatly affected by the organic-mineral composites. In this study, goethite-fulvic acid (Ge-FA) composites with varying FA mass ratios in the range of 0-15% were synthesized by coprecipitation. The sample properties were studied using XRD, FTIR, SEM-EDS and N2 gas adsorption techniques. The influence of Ge-FA on the mobility of Pb/Cd in soil was investigated. The crystal forms of Ge-FA changed from goethite (FA≤4%) to hematite (FA≥5%), and the FA affected the FeO bond vibrations. These results demonstrated that FA was successfully introduced into the iron oxide. Ge-FA changed from a filamental morphology to an aggregate as the FA ratio increased. The coprecipitation resulted in blockages of iron oxides, thereby decreasing the specific surface area and pore volume. The adsorption amount of Pb(II) on Ge-FA increased as the FA ratio increased, but no significant change was observed for Cd(II). With the application of Ge-FA, the exchangeable concentrations of Pb and Cd in contaminated soil decreased by 42.4%-93.6% and 15.8%-43.7%, respectively. The exchangeable and carbonate bound fractions of Pb and Cd decreased and were transformed into the FeMn bound and residual fractions.


Asunto(s)
Benzopiranos/química , Cadmio/metabolismo , Compuestos de Hierro/química , Plomo/metabolismo , Minerales/química , Contaminantes del Suelo/metabolismo , Suelo/química , Propiedades de Superficie
15.
Environ Sci Pollut Res Int ; 26(7): 7024-7032, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30645741

RESUMEN

The adsorption mechanism of Cd (II) was investigated by Pennisetum sp. straw biochars (JBC) that were modified by two different methods: KMnO4 impregnation (JMB1) and H2O2 impregnation (JMB2). A scanning electron microscope and energy-dispersive spectroscopy (SEM-EDS), X-ray diffraction (XRD), a Fourier transform infrared spectrometer (FTIR), and a Brunauer-Emmett-Teller (BET) specific surface area analysis were employed to examine the physicochemical characteristics of biochars. The Cd(II) adsorption kinetic fit, the Langmuir model well, and the maximum adsorption capacity occurred in the following order: JMB1 (90.32 mg/g) > JMB2 (45.18 mg/g) > JBC (41.79 mg/g), suggesting that JMB1 had an excellent adsorption performance. Finally, X-ray photoelectron spectroscopy (XPS) was used to explore the main adsorption mechanism. Our results showed that JMB1 was an excellent adsorbent in removing Cd(II) from aqueous solution.


Asunto(s)
Cadmio/química , Carbón Orgánico/química , Modelos Químicos , Pennisetum/química , Adsorción , Peróxido de Hidrógeno , Cinética , Espectroscopía de Fotoelectrones , Espectrometría por Rayos X , Espectroscopía Infrarroja por Transformada de Fourier , Difracción de Rayos X
16.
Sci Total Environ ; 655: 614-621, 2019 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-30476842

RESUMEN

Rational modification of the surface structure and interface structure can effectively optimize the catalytic performance and stability of a heterogeneous catalyst. A CoO-CuO bimetallic catalyst with a special urchin-like structure was prepared by a hydrothermal urea precipitation method. This carbon nanosphere template method significantly improves the dispersibility of the material. The special urchin-like nanorod structure expands the specific surface area, resulting in excellent adsorption performance and high catalytic performance. The materials were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The oxidative degradation mechanism of dibutyl phthalate (DBP) using sodium persulfate (SPS) activated by the CoO-CuO double metal oxide catalyst was explored. The synergy between the two metals gives the material a stable and highly catalytic ability.

17.
Sci Total Environ ; 658: 836-842, 2019 Mar 25.
Artículo en Inglés | MEDLINE | ID: mdl-30583179

RESUMEN

Lignin is a renewable aromatic polymer which is present in large quantities in the cell walls of terrestrial plants and is the main binding agent for fibrous plant components. Potassium lignosulfonate (KLS), as a by-product of pulping processes, can be applied to agricultural fields as a soil conditioner and chelate fertilizer. In this study, based on its solubility and complexing ability, batch washing and column leaching was explored to evaluate the potential application of KLS in the washing remediation of soil contaminated with lead and copper. Under optimum conditions KLS concentration of 8%, pH of 5.24 and 6 h duration, the removal ratios for the simulated and mining area soils in the batch experiment were 67.40% and 52.87% respectively, for Pb and 73.42% and 55.20% respectively, for Cu. In the column leaching experiment, the removal efficiencies of Pb and Cu increased with solution volume and that the removal ratios of the simulated and mining area soils were 36.46% and 20.31%, respectively, for Pb and 39.74% and 22.76%, respectively, for Cu. KLS can reduce the ratio of acid-soluble and reducible fractions, which may have the most potential hazardous and poisonous for plants. Cation exchange capacity (CEC) and pH of soil were all stable after washing. However, the organic matter and available K, N, and P in the treated soil, which are important factors for plant growth increased significantly. This study showed that KLS can remove Pb and Cu from soil, while improve nutrient (ammonium nitrogen, available phosphorus and available potassium) levels of soil.

18.
Huan Jing Ke Xue ; 39(6): 2927-2935, 2018 Jun 08.
Artículo en Chino | MEDLINE | ID: mdl-29965652

RESUMEN

The safety of vegetable production is a key link in reducing cadmium consumption through the food chains. Field experiments were conducted to investigate the effects of composite materials (calcium silicate-biological humus fertilizer) on the growth of shallots and the uptake of Cd by shallots from contaminated agricultural soil. Four treatments (T1: 0.5% calcium silicate+0.5% biological humus fertilizer; T2: 0.5% calcium silicate+1.0% biological humus fertilizer; T3: 1.0% calcium silicate+0.5% biological humus fertilizer; and T4: 1.0% calcium silicate+1.0% biological humus fertilizer) and a control group (CK) were adopted. The changes in soil pH, DTPA-extractable Cd, biomass of shallots, and cadmium concentrations in shallots over time under different treatments were analyzed. The results show that the application of composite amendments decreased the concentrations of DTPA-extractable Cd in the soil. In particular, after T3 treatment, the concentrations of soil DTPA-extractable Cd decreased by 60.71%, 49.54%, 44.63%, and 58.94% after 14, 28, 42, and 56 d, respectively. The biomass of the shallots aboveground increased significantly by 107.99% and 107.19% after T3 and T4 treatment, respectively. The composite amendments exhibited different effects on the uptake of Cd by the shallots from the soil, and the T4 treatment was the most effective in immobilizing Cd and inhibiting translocation of Cd into the shallots. The cadmium concentration in the shallots decreased by 43.80% after 56 d with the T4 treatment. In conclusion, T4 is the optimum treatment for soil cadmium immobilization.


Asunto(s)
Cadmio/metabolismo , Compuestos de Calcio/química , Fertilizantes , Chalotes/metabolismo , Silicatos/química , Contaminantes del Suelo/metabolismo , Suelo/química , Chalotes/efectos de los fármacos
19.
Environ Sci Pollut Res Int ; 25(14): 14032-14042, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29520542

RESUMEN

In this study, a magnesium oxide-rice husk biochar composite (MgO-BCR) was successfully prepared by a MgO impregnation method, and its adsorption performance was investigated in Cd(II) aqueous solution. A pseudo-second-order kinetic model described the Cd(II) adsorption behaviour on BCR and MgO-BCR well, while a Langmuir adsorption isotherm was more suitable for Cd(II) adsorption on the adsorbent. The fitting results of the monolayer model indicated that the number of ions captured by per site varied between 0.97 and 1.09. The calculated thermodynamic parameters indicated that Cd(II) adsorption onto MgO-BCR was spontaneous and endothermic. Characterisation of the adsorbent revealed that in situ precipitation, surface complexation, and electrostatic attraction contributed to the Cd(II) adsorption. The adsorption capacities of rice husk biochar (BCR) and MgO-BCR for Cd(II) reached 6.36 and 18.1 mg/g, respectively. The results demonstrated that MgO-BCR composite could be used as an effective and eco-friendly adsorbent to enhance the removal of Cd(II) from aqueous solution.


Asunto(s)
Cadmio/análisis , Carbón Orgánico/química , Óxido de Magnesio/química , Oryza/química , Eliminación de Residuos Líquidos/métodos , Contaminantes Químicos del Agua/análisis , Adsorción , Cinética , Modelos Químicos , Termodinámica
20.
J Sep Sci ; 41(8): 1812-1820, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-29330898

RESUMEN

A quick, easy, cheap, effective, rugged, and safe procedure was designed to extract pesticide residues from fruits and vegetables with a high percentage of water. It has not been used extensively for the extraction of phthalate esters from sediments, soils, and sludges. In this work, this procedure was combined with gas chromatography with mass spectrometry to determine 16 selected phthalate esters in soil. The extraction efficiency of the samples was improved by ultrasonic extraction and dissolution of the soil samples in ultra-pure water, which promoted the dispersion of the samples. Furthermore, we have simplified the extraction step and reduced the risk of organic solvent contamination by minimizing the use of organic solvents. Different extraction solvents and clean-up adsorbents were compared to optimize the procedure. Dichloromethane/n-hexane (1:1, v/v) and n-hexane/acetone (1:1, v/v) were selected as the extractants from the six extraction solvents tested. C18/primary secondary amine (1:1, m/m) was selected as the sorbent from the five clean-up adsorbents tested. The recoveries from the spiked soils ranged from 70.00 to 117.90% with relative standard deviation values of 0.67-4.62%. The proposed approach was satisfactorily applied for the determination of phthalate esters in 12 contaminated soil samples.

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