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1.
Appl Opt ; 62(30): 8159-8167, 2023 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-38038113

RESUMEN

The multi-focus metalens can couple the light into multiple channels in optical interconnections, which is beneficial to the development of planar, miniaturized, and integrated components. We propose broadband photonic spin Hall effect (PSHE) driven multi-focus metalenses, in which each nanobrick plays a positive role for all focal points. Three PSHE driven metalenses with four, six, and eight focal points have been designed and investigated, respectively. Under the incidences of left-/right-handed circularly polarized (LCP/RCP) light, these metalenses can generate regularly distributed two, three, and four RCP/LCP focal points, respectively. The uniformity of the focusing intensity has been investigated in detail by designing an additional four six-focus metalenses with different focus distributions. The uniqueness of these metalenses makes this design philosophy very attractive for applications in spin photonics, compact polarization detection, multi-imaging systems, and information processing systems.

2.
EClinicalMedicine ; 65: 102305, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37965431

RESUMEN

Background: Glibenclamide alleviates brain edema and improves neurological outcomes in experimental models of stroke. We aimed to assess whether glibenclamide improves functional outcomes in patients with acute ischemic stroke treated with recombinant tissue plasminogen activator (rtPA). Methods: In this randomized, double-blind, placebo-controlled trial, patients with acute ischemic stroke were recruited to eight academic hospitals in China. Patients were eligible if they were aged 18-74 years, presented with a symptomatic anterior circulation occlusion with a deficit on the NIHSS of 4-25, and had been treated with rtPA within 4.5 h of symptom onset. We used web-based randomization (1:1) to allocate eligible participants to the glibenclamide or placebo group, stratified according to endovascular treatment and baseline stroke severity. Glibenclamide or placebo was taken orally or via tube feeding at a loading dose of 1.25 mg within 10 h after symptom onset, followed by 0.625 mg every 8 h for 5 days. The primary outcome was the proportion of patients with good outcomes (modified Rankin Scale of 0-2) at 90 days, assessed in all randomly assigned patients who had been correctly diagnosed and had begun study medication. The study is registered with ClinicalTrials.gov, NCT03284463, and is closed to new participants. Findings: Between January 1, 2018, and May 28, 2022, 305 patients were randomly assigned, of whom 272 (142 received glibenclamide and 130 received placebo) were included in the primary efficacy analysis. 103 (73%) patients in the glibenclamide group and 94 (72%) in the placebo group had a good outcome (adjusted risk difference 0.002, 95% CI -0.098 to 0.103; p = 0.96). 12 (8%) patients allocated to glibenclamide and seven (5%) patients allocated to placebo died from any cause at 90 days (p = 0.35). The number and type of adverse events were similar between the two groups. There were no drug-related adverse events and no drug-related deaths. Interpretation: The addition of glibenclamide to thrombolytic therapy did not increase the proportion of patients who achieved good outcomes after stroke compared with placebo, but it did not lead to any safety concerns. Funding: Southern Medical University and Nanfang Hospital.

3.
Sci Total Environ ; 897: 165399, 2023 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-37442478

RESUMEN

Photoconversion of tetracycline (TC) has been widely reported. However, the effect of microplastics (MPs) on TC conversion kinetics and mechanism has rarely been discussed. In this study, we investigated the effect of (aged) MPs on TC degradation under simulated sunlight and elucidated the underlying mechanism. Our findings demonstrated that the physical and chemical properties of polystyrene (PS), such as particle size, surface groups, and morphology, were significantly altered after aging. Moreover, photoconversion efficiency of TC was suppressed with the spiking of aged PS, while virgin PS showed an opposite tendency. The photodegradation reaction for photosensitization of PS involved 1O2 and HO·. The light-screening effect of aged PS occupied predominance, weakening the direct UV-light absorption of TC and resulting in lower TC degradation efficiency. Additionally, triplet-excited state PS was generated after photon acceptance by aged PS, which could transfer energy to O2, leading to the production of 1O2. The toxicity test manifested that the direct impact of TC products on fathead minnow was ignorable, but long-term negative effects on growth deserved observation. This study enhances our understanding of the environmental fate of PS and TC under sunlight, and provides crucial reference information for better evaluating the potential risk of MPs and chemicals.


Asunto(s)
Compuestos Heterocíclicos , Contaminantes Químicos del Agua , Poliestirenos/toxicidad , Poliestirenos/química , Microplásticos/toxicidad , Microplásticos/química , Luz Solar , Plásticos , Contaminantes Químicos del Agua/análisis , Tetraciclina/toxicidad , Antibacterianos
4.
Waste Manag ; 158: 164-175, 2023 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-36716656

RESUMEN

The Fe(II)/CaO2 system with a stable oxidant and a low-cost homogeneous activating agent has been considered as a prospective process for the disposal of wastewater. The system was constructed to treat sewage sludge hydrothermal carbonization aqueous phase (HTC-AP) in this study. As the hydrothermal temperature increased, the organics in the HTC-AP were first decomposed and then cyclized, while the Maillard reaction occurs throughout the stage. The oxidation efficiency of the Fe(II)/CaO2 system was related to the composition of organics in HTC-AP, and the removal of dissolved organic carbon (DOC) by the system was 38.56 % in the HTC-AP obtained by hydrothermal treatment at 220 °C. Redundancy analysis showed that the low molecular weight organics, hydrophobic acids, and hydrophobic neutral components were beneficial to DOC removal, while Maillard products and cyclization products were hard to be oxidized to CO2 and H2O. The CN functional group of the protein facilitated DOC removal, and some organics in HTC-AP were oxidized to acids and phenols. The energy input to remove DOC in Fe(II)/CaO2 system was 27.74 MJ per kg carbon. This study provides a low-energy consumption Fe(II)/CaO2 system for the post-treatment of HTC-APs and explores the applicability of the system.


Asunto(s)
Aguas del Alcantarillado , Aguas Residuales , Aguas del Alcantarillado/química , Carbono/química , Fenoles , Materia Orgánica Disuelta , Compuestos Ferrosos , Temperatura
5.
Opt Lett ; 48(1): 113-116, 2023 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-36563383

RESUMEN

In this Letter, by cascading several bichromatic photonic crystals we demonstrate that the quality factor can be much larger compared with that in an isolated cavity without increasing the total size of a device. We take a lithium niobate photonic crystal as an example to illustrate that the simulated quality factor of the cascaded cavity can reach 105 with a 70° slant angle, which is an order of magnitude larger than that in an isolated cavity. The device can be fabricated easily by current etching techniques for lithium niobate. We have fabricated the proposed device experimentally including holes with ∼70° slant angle. This work is expected to provide guidance to the design of photonic crystal cavities with high quality factor.

6.
Microbes Infect ; 25(1-2): 105020, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-35792202

RESUMEN

BACKGROUND: The purpose of this research was to evaluate the effect of clofazimine on drug-resistant tuberculosis treatment outcomes. METHODS: A systematic search was conducted in the PubMed, Web of Science and EMBASE databases to identify eligible studies published up to July 10, 2021. The search terms were as follows: "clofazimine," "tuberculosis," "multidrug resistant tuberculosis" or "extensively drug resistant tuberculosis" and their synonyms or similar words. Two researchers independently screened the titles, abstracts, and full texts for inclusion. Meta-analysis was performed with Stata version 16.0 (Stata Corp., College Station, Texas, USA). Risk ratios (RRs) with 95% CIs were calculated to evaluate the treatment outcome. RESULTS: Eight studies including 3219 participants were included in the meta-analysis. The meta-analysis found that the rates of treatment completion was higher in patients receiving clofazimine-containing regimens than in those not receiving clofazimine-containing regimens (RR: 1.185 (1.060-1.325), P = 0.003). Significant reduction in treatment failure (RR: 0.598 (0.473-0.756), P < 0.001) was found in the clofazimine treatment group. The subgroup analyses of randomized controlled trials (RCTs) found a higher rates of favorable outcomes, treatment completion and cure in the clofazimine group than in the control group (RR: 1.203 (1.029-1.407), P = 0.020; RR: 3.167 (2.043-4.908), P < 0.001; and RR: 1.251 (1.031-1.518), P = 0.023, respectively). Patients receiving clofazimine had a lower risk of treatment failure than those not receiving clofazimine (RR: 0.529 (0.454-0.616), P < 0.001). However, clofazimine treatment did not have a statistically significant effect on all-cause mortality in RCTs. CONCLUSIONS: This study demonstrated that compared with patients who do not receive clofazimine, this drug has the potential to achieve a higher favorable outcome, treatment completion and cure rates, and a lower treatment failure risk among drug-resistant tuberculosis cases.


Asunto(s)
Tuberculosis Extensivamente Resistente a Drogas , Tuberculosis Resistente a Múltiples Medicamentos , Humanos , Antituberculosos/uso terapéutico , Clofazimina/uso terapéutico , Tuberculosis Extensivamente Resistente a Drogas/tratamiento farmacológico , Resultado del Tratamiento , Tuberculosis Resistente a Múltiples Medicamentos/tratamiento farmacológico
7.
Front Psychiatry ; 13: 985823, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36339832

RESUMEN

Background: Depression and anxiety are major psychological issues among patients with tuberculosis (TB) owing to chronic and complex treatments, have been reported to be closely correlated with immune and inflammation. However, the association of peripheral immune-inflammatory characteristics with depression/anxiety symptoms in in-patients with TB has rarely been reported. Methods: A cross-sectional study of 338 in-patients with TB from 3 hospitals in China were enrolled to investigate their depression and anxiety status by using the nine-item Patient Health Questionnaire (PHQ-9) and seven-item Generalized Anxiety Disorder Scale (GAD-7). Participants were divided into groups based on their PHQ-9 and GAD-7 scores, and differences in demography and immune-inflammatory characteristics were studied. Logistic analysis was performed to explore factors related to depression and anxiety symptoms. Results: Depression and anxiety prevalence among patients with TB was 47.9 and 42.6%, respectively. Furthermore, 38.5% of patients reported a comorbidity of depression and anxiety symptoms. The counts of CD3, CD4, CD8, and lymphocytes decreased, whereas those of neutrophils, platelets, and peripheral blood cells and their derived indices increased among TB patients with depression or anxiety in comparison with those without symptoms (p < 0.05). In addition, increasing age, lower income (monthly income ≤ 3,000 yuan), divorced or widowed, drug resistance, and higher systemic immune inflammation index (SII) were significantly associated with depression or anxiety symptoms (p < 0.05). Conclusion: Approximately half of the patients with TB suffered from depression or/and anxiety symptoms. Patients with depression or anxiety present worse cell immune status and stronger inflammatory responses compared to those without symptoms. We emphasized the importance of paying attention to the dysfunction of immune-inflammation process of TB patients with depression or anxiety symptoms. Especially, SII has a potential application value in guiding the evaluation of TB-related depression or anxiety owing to its easily accessibility and being economical.

8.
Chemosphere ; 288(Pt 2): 132549, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34653483

RESUMEN

Without extra adjustment of pH, the effects of cupric ions (Cu(II)) and hydrogen peroxide (H2O2) alone or in combination on sludge dewatering were studied. It showed good dewatering capability after treated by Cu(II) and Cu(II)/H2O2, which indicated by the capillary suction times (CST) decreased from 120.8 ± 4.7 s (control) to about 40 s, and the water content (Wc) of sludge cake dropped by about 10%. The results showed that the extracellular polymeric substances (EPS) were destroyed, which characterized by a significant decrease in the biopolymers' concentrations in tightly-bound EPS. Meanwhile, more rough and porous microstructures and higher zeta potentials were obtained after conditioned. Based on the changes of physicochemical properties of sludge, the variations of EPS, and the identification of reactive species, two distinct mechanisms of improved sludge dewatering were postulated. As for Cu(II) treatment, it was mainly due to the surface charge neutralization, strong cytotoxicity of Cu(I) produced by intracellular reduction of Cu(II), and pH decline caused by Cu(II) hydrolysis that improved sludge dewatering performance, which could be noted as a "non-radical pathway". When in combination with H2O2, hydroxyl radicals (·OH) produced by Cu(II)-catalyzed Fenton-like process played a dominant role in degrading sludge flocs and EPS, which could be regarded as a "radical pathway".


Asunto(s)
Peróxido de Hidrógeno , Aguas del Alcantarillado
9.
Chemosphere ; 291(Pt 3): 133053, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-34861255

RESUMEN

Phosphorus is a nutrient that is essential to nature and human life and has attracted attention because of its very limited reserves. Dwindling phosphorus reserves and soaring prices have made the recovery of phosphorus from waste biosolids even more urgent. Waste activated sludge, as the final destination of most of the phosphorus in human domestic and industrial water, has been considered as a reliable source of phosphorus recovery. The thermal treatment method of sewage sludge is currently a relatively environmentally friendly disposal method, which mainly includes incineration, pyrolysis and hydrothermal carbonization. This paper reviews the methods for the recovery of different forms of phosphorus (wet chemical, thermochemical and electrodialysis) from solid products obtained from different sludge thermal treatment methods (incinerated sewage sludge ash, pyrolysis of sewage sludge char and hydrochar) and the bioavailability of the recovered phosphorus products. Incineration of sewage sludge is currently the most established and effective method for recovering phosphorus from the thermal treatment products of sewage sludge. One of the wet chemical methods has been applied on a commercial scale and is expected to be further developed for future industrial applications. Pyrolysis and hydrothermal carbonation still have many research gaps in this field. Based on their principles and laboratory performance, both of them have the potential to recover phosphorus and should be further explored.


Asunto(s)
Fósforo , Aguas del Alcantarillado , Disponibilidad Biológica , Humanos , Incineración , Pirólisis
10.
Front Public Health ; 10: 1047425, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36684994

RESUMEN

Background: Tuberculosis (TB) patients commonly suffer from sleep issues owing to various adverse drug reactions (ADRs), disease symptoms, and the contagious nature of their disease. These sleep issues negatively affect the treatment outcome and quality of life. However, the prevalence of sleep disturbance and its associated factors among TB patients have rarely been reported. Methods: A total of 497 inpatients with TB from three hospitals in China were enrolled in this cross-sectional study to investigate their sleep quality using the Pittsburgh sleep quality index (PSQI). Clinical data, including demographic information, TB-related stigma, perceived stress, and nutrition- and immunity-related indicators, were also collected to explore the factors associated with sleep disturbance among the recruited patients. Results: Approximately 70% of the recruited patients reported a sleep disturbance to varying degrees, presenting poorer global and subjective sleep qualities, longer sleep latency, shorter sleep duration, lower sleep efficiency, more frequent sleep disturbances, greater use of sleeping medication, and more severe daytime dysfunction. Furthermore, the body mass index (BMI), hemoglobin levels, albumin levels, and T lymphocyte count of the patients in the poor sleep quality group were significantly lower than those in the good sleep quality group (p < 0.05). Increasing age, higher income, drug resistance, higher stigma or stress perception, lower albumin levels, and lower CD4 levels were significantly associated with sleep disturbance among TB patients (p < 0.05). Conclusion: Three-quarters of the participants were found to suffer from a probable sleep disturbance. And sleep problems are linked to biological traits that interact with psychological, cultural, and social factors in complex ways. It is therefore important to pay attention to the sleep quality of TB patients, especially those with the identified risk factors. Besides, taking care of these risk factors may prove to be an effective sleep management strategy.


Asunto(s)
Calidad del Sueño , Tuberculosis , Humanos , Albúminas , Estudios Transversales , Calidad de Vida , Tuberculosis/psicología
11.
Opt Lett ; 46(21): 5505-5508, 2021 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-34724512

RESUMEN

The erbium-doped lithium niobate on insulator (LNOI) laser plays an important role in the complete photonic integrated circuits (PICs). Here, we demonstrate an integrated tunable whispering gallery single-mode laser (WGSML) by making use of a coupled microdisk and microring on LNOI. A 974 nm single-mode pump light can have an excellent resonance in the designed microdisk, which is beneficial to the whispering gallery mode (WGM) laser generation. The WGSML at 1560.40 nm with a maximum 31.4 dB side mode suppression ratio (SMSR) has been achieved. By regulating the temperature, the output power of the WGSML increases, and the central wavelength can be changed from 1560.30 to 1560.40 nm. Furthermore, 1560.60 and 1565.00 nm WGSMLs have been achieved by changing the coupling gap width between the microdisk and microring. We can also use the electro-optic effect of LNOI to obtain more accurate adjustable WGSMLs in further research.

12.
Chemosphere ; 277: 130362, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-34384191

RESUMEN

Low-temperature magnetic pyrolysis (LMP) of municipal solid waste (MSW) was conducted in a pilot scale continuous reactor to investigate the distribution and transformation of heavy metals (HMs) in biochar. Environmental safety was evaluated by the risk assessment code (RAC) and the modified potential ecological risk index (MRI). Statistical analyses of HMs revealed that the total concentrations of HMs in biochar was higher than that in MSW and the exchangeable fraction of Cd in biochar under 200 °C and 250 °C were at high risk levels. Temperature increment indicates an increase in regular steps not only migrated more HMs into biochar, but also broke the immobilization of HMs, so resulted in higher environmental risks. The lowest direct toxicity to the environment was obtained by LMP at 200 °C. In light of the residual fraction and the high concentration of HMs in biochar produced in this work, it should be mixed with other uncontaminated plant waste for further application in agriculture. The results of economic assessment reveal that the value of net present value (NPV) and the internal rate of return (IRR) can be positive if high quality bio-products are produced with low operating costs. Optimized design of operation, feedstock and the investment are the key factors to improve the economic feasibility of LMP.


Asunto(s)
Metales Pesados , Pirólisis , Carbón Orgánico , Estudios de Factibilidad , Metales Pesados/análisis , Medición de Riesgo , Aguas del Alcantarillado , Residuos Sólidos , Temperatura
13.
Nanomaterials (Basel) ; 11(6)2021 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-34205174

RESUMEN

In this paper, one spin-selected vortex metalens composed of silicon nanobricks is designed and numerically investigated at the mid-infrared band, which can produce vortex beams with different topological charges and achieve different spin lights simultaneously. Another type of spin-independent vortex metalens is also designed, which can focus the vortex beams with the same topological charge at the same position for different spin lights, respectively. Both of the two vortex metalenses can achieve high-efficiency focusing for different spin lights. In addition, the spin-to-orbital angular momentum conversion through the vortex metalens is also discussed in detail. Our work facilitates the establishment of high-efficiency spin-related integrated devices, which is significant for the development of vortex optics and spin optics.

15.
Bioresour Technol ; 322: 124543, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33348116

RESUMEN

The influence of persulfate assisted hydrothermal carbonization (HTC) (160 °C-220 °C) of spirulina and hydrochar properties was assessed. The elementary composition and proximate analysis of hydrochar were investigated on the carbonization degree and basic fuel properties, and the surface functional groups and morphological characteristics of hydrochar were analyzed as well as thermal stability. Results suggested that persulfate assisted process enhanced the carbonization degree of hydrochar by oxygen reduction (1.53%-2.74%) and increase of C ratio, and HHVs increased 0.81-1.39 MJ/kg at temperature above 180 °C. The -OH and CO on hydrochar surface were significantly reduced, and C-(C, H) and C-(O, N) were weakened by persulfate addition and more C-H peaks was formed. Additionally, the persulfate addition enhanced the thermal stability of hydrochar by lowing the maximum mass loss rate. The result suggested that HTC can be conducted with persulfate at lower temperature for hydrochar biofuel production.


Asunto(s)
Spirulina , Biocombustibles , Carbono , Temperatura
16.
Biosci Rep ; 40(8)2020 08 28.
Artículo en Inglés | MEDLINE | ID: mdl-32648572

RESUMEN

Genetic polymorphisms for tuberculosis (TB) susceptibility have been researched by some studies, but few have studied multiple innate immunity genes associated with TB. Evidence suggests that the toll-like receptor 2, 4 (TLR2, TLR4) and toll interacting protein (TOLLIP) may be associated with TB susceptibility. In this self-validated study, we explored the association between common single nucleotide polymorphisms (SNPs) of TLR2, TLR4 and TOLLIP in the Chinese Han and Tibetan populations. A SNPscan™ method was used to genotype SNPs in the three genes. Multiple logistic regression adjusted by sex and age was used to detect the association between SNPs and TB. In TLR2, rs1898830 was associated with decreased risk against TB in the Chinese Han population, which was validated in the Tibetan population. In TLR4, rs11536889 was a protective factor for TB in the Tibetan population, but not in the Han population. Additionally, in the Tibetan population, we also found that the frequency of genotypes of TOLLIP rs11536889 differs significantly between TB patients and controls. We found rs1898830 in TLR2 was associated with TB susceptibility in both Chinese Han and Tibetan populations while rs11536889 in TLR4 and rs3750920 in TOLLIP were protective factors against TB in the Tibetan population.


Asunto(s)
Péptidos y Proteínas de Señalización Intracelular/genética , Polimorfismo de Nucleótido Simple , Receptor Toll-Like 2/genética , Receptor Toll-Like 4/genética , Tuberculosis/genética , Adulto , Pueblo Asiatico/genética , Estudios de Casos y Controles , China/epidemiología , Femenino , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Humanos , Masculino , Persona de Mediana Edad , Fenotipo , Factores Protectores , Medición de Riesgo , Factores de Riesgo , Tuberculosis/diagnóstico , Tuberculosis/etnología , Tuberculosis/prevención & control , Adulto Joven
17.
Waste Manag ; 114: 225-233, 2020 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-32682087

RESUMEN

In this study, the effects of different biochar catalysts on the quality of bio-oil derived from the co-pyrolysis of sewage sludge (SS) and rice husk (RH) are explored. Catalysts include SS biochar (SWC), RH biochar (RHC), mixed SS and RH biochar (SRC), and RH ash (RHA). The quality of bio-oil was evaluated based on the results of gas chromatography-mass spectrometry (GC-MS; including the contents of hydrocarbons and N-species), oxygen content, higher heating value, and pH. The GC-MS analysis results illustrated that N-species content in the bio-oil reduced with the addition of the biochar catalyst, while the hydrocarbons content increased from 15.51% for co-pyrolysis to 38.74-61.84% for different biochar catalysts at a catalytic temperature of 650 °C. RHC exhibited the best catalytic effect in terms of decreasing the content of N-species by 58.79% and increasing the content of hydrocarbons by nearly four times compared to co-pyrolysis. The higher heating value of bio-oil raised from 25.75 to 34.67 MJ/kg, while oxygen content decreased from 31.1 to 8.81 wt%, and the pH increased from 4.06 to 5.48. Moreover, the catalytic mechanism of catalytic co-pyrolysis over RHC, including the hydrocarbon generation pathway and nitrogen removal, is also discussed here. High specific surface area of RHC provides sufficient active sites (e.g. O-containing and N-containing functional groups) for the catalytic reaction of pyrolytic intermediates.


Asunto(s)
Oryza , Pirólisis , Biocombustibles , Carbón Orgánico , Calor , Aceites de Plantas , Polifenoles , Aguas del Alcantarillado
18.
J Colloid Interface Sci ; 574: 122-130, 2020 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-32305728

RESUMEN

This study synthesized nanocomposite catalysts via a modification of Re/Pd codoped carbon nanotubes (CNTs) with different concentrations of polydopamine (PDA), which were used for perchlorate (ClO4-) reduction. The loads, dispersion and reducibility of Re/Pd nanoparticles increased yet their particle sizes significantly decreased with the increase of PDA concentrations. The average diameter of Re/Pd codoped D2CNT (CNT modified by 2 mg/mL PDA) with a narrow size distribution was measured to be 2 nm. The ultrafine Re/Pd codoped D2CNT catalysts represented outstanding catalytic reduction activity for the conversion of ClO4- to Cl- with TOF of 17.34 h-1 under the room H2 atmospheric pressure, which was about 8 times than that of the unmodified catalysts. Furthermore, PDA modification minimized the dissociation of Re by chemical bonding between Re and CNTs carrier and maintained good stability of nanocomposite. This study inspires us to apply green bionic methods to enhance the catalytic reduction of perchlorate by changing the physical properties of Re/Pd nanoparticles.

19.
Environ Pollut ; 260: 114067, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32014751

RESUMEN

To understand the effect of reaction temperature on sulfur during hydrothermal carbonization (HTC) of sewage sludge (SS), seven group of temperature (180-300 °C) were chosen to investigate the distributions and evolution of sulfur-containing compounds in hydrochar and the liquid products. Elemental analysis, X-ray photoelectron spectroscopy (XPS), and X-Ray powder diffraction (XRD) were used to characterize the distribution of sulfur in hydrochar. The concentrations of sulfate ions and sulfide were determined in the liquid sample. The experimental results showed that as the temperature increased, the O/C ratio decreased because of the improved carbonization degree of SS. After hydrothermal carbonization, 90% of the sulfur in SS remained in hydrochar. As the temperature increased, the amount of sulfur in the liquid, mainly in the form of sulfate ions, tended to decrease. However, the experimental results for the gas phase were the opposite of the liquid phase.


Asunto(s)
Aguas del Alcantarillado , Azufre , Temperatura , Eliminación de Residuos Líquidos , Carbono
20.
J Hazard Mater ; 388: 122084, 2020 04 15.
Artículo en Inglés | MEDLINE | ID: mdl-31972434

RESUMEN

In this study, hydrothermal carbonization (HTC) of sewage sludge(SS) was carried out at a temperature of 270℃ and a resulting pressure of 7-9 MPa with 2 h. The effect of feed water pH values in the range of 2-12 on hydrochar characteristics, organic component and thermal behavior was evaluated. The result shows that with the pH value increasing, ash content shows a trend of decline, and organic components in the hydrochar become significantly simpler than SS. hydrochar is more beneficial to produce a fatty substance during an acidic environment and alkaline environments favor the formation of N-containing organic compounds and ketone organics, especially in strongly alkaline environments. Compared to the SS, hydrochar burning interval shortened 100℃ and the combustion of hydrochar is more durable. Considering the organic composition and combustion performance of hydrochar, it is found that the hydrochar prepared under 270-5 condition has the best effect.

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