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1.
Ecotoxicol Environ Saf ; 264: 115455, 2023 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-37708689

RESUMEN

The involvement of fine particulate matter (PM2.5) exposure in the progression of asthma has been extensively discussed in epidemiological and experimental evidence, which aroused widespread attention. Asthma is characterized by mucus hypersecretion. This study investigates the underlying toxic mechanism of traffic-related PM2.5 (TRPM2.5) and water-soluble extracts (WSE) on mucus hypersecretion in the lungs of rats with asthma and 16HBE cells. The ovalbumin-induced rats were administrated by instillation of TRPM2.5 and WSE in the trachea once three days for eight times. The results showed that TRPM2.5 and WSE had an adverse impact on mucus secretion. Specifically, conspicuous mucus stains and increased goblet cells in the bronchial epithelium by PAS staining were found in lung tissues of rats with asthma; MUC5AC gene and protein expression levels in lung tissues of rats with asthma and 16HBE cells were elevated. In addition, TRPM2.5 and WSE triggered oxidative damage via upregulation of malondialdehyde and myeloperoxidase as well as activation of the Sestrin2/Keap1/Nrf2 signaling pathway. Conversely, the knockdown of Sestrin2 effectively inhibited TRPM2.5 and WSE-induced mucus hypersecretion, oxidative stress, and Keap1/Nrf2 signaling pathway and its downstream target gene NQO1. Collectively, it was demonstrated that TRPM2.5 and WSE induced mucus hypersecretion mediated by the Sestrin2/Keap1/Nrf2 pathway.


Asunto(s)
Asma , Canales Catiónicos TRPM , Animales , Ratas , Factor 2 Relacionado con NF-E2/genética , Proteína 1 Asociada A ECH Tipo Kelch/genética , Asma/inducido químicamente , Epitelio , Moco , Colorantes , Pulmón
2.
J Environ Manage ; 333: 117416, 2023 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-36758403

RESUMEN

Electrocoagulation (EC) is a promising alternative for decentralized drinking water treatment in rural areas as a chemical-free technology. However, seasonal fluctuations of water quality in influent remain a significant challenge for rural decentralized water supply, which was a potential threat to water safety. The frequent operation was required to ensure the effluent water quality by the experienced technicians, who were in shortage in rural areas. If the operational parameters prediction model based on water quality could be established, it might reduce the dependence on technicians. Therefore, an artificial neural network (ANN) model combined with genetic algorithm (GA) was used to establish a prediction model for unattended intelligent operation. Data on water quality and operational parameters were collected from a practical EC system in a decentralized water treatment plant. Seven water quality parameters (e.g., turbidity, temperature, pH and conductivity) were selected as input variables and the operational current was employed as the output. A non-linear relationship between water quality parameters and the operational current was verified by correlation analysis and principal component analysis (PCA). The mean squared error (MSE) and coefficient of determination (R2) were used as evaluation indexes to optimize the structure of the GA-ANN model. Influent turbidity was identified to be crucial in the GA-ANN model by model interpretation using sensitivity analysis and scenario analysis. The Garson weight of turbidity in the seven input variables achieved 45.4%. The predictive accuracy of the GA-ANN model sharply declined from 90% to 67.1% when influent turbidity data were absent. In addition, it was estimated that energy consumption savings of the GA-ANN method declined by 14.2% in comparison with the gradient control method. This study verifies the feasibility and stability of machine learning strategy for unattended operation in the rural decentralized water treatment plant.


Asunto(s)
Redes Neurales de la Computación , Purificación del Agua , Calidad del Agua , Purificación del Agua/métodos , Electrocoagulación , Aprendizaje Automático
3.
Neurocrit Care ; 36(2): 395-403, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-34313936

RESUMEN

BACKGROUND: Studies of the impact of increased hemoglobin on spontaneous intracerebral hemorrhage (ICH) are limited. The present study aimed to explore the effect of increased hemoglobin on ICH. METHODS: A retrospective single-center study using medical records from a database processed by univariate and multivariate analyses was performed in the People's Hospital of Tibet Autonomous Region in Lhasa, Tibet, China. RESULTS: The mean hemoglobin level in 211 patients with ICH was 165.03 ± 34.12 g/l, and a median hematoma volume was 18.5 ml. Eighty-eight (41.7%) patients had large hematomas (supratentorial hematoma ≥ 30 ml; infratentorial hematoma ≥ 10 ml). No differences in ICH risk factors between the groups with different hemoglobin levels were detected. Increased hemoglobin was independently associated with large hematomas [odds ratio (OR) 1.013, P = 0.023]. Increased hemoglobin was independently associated with ICH with subarachnoid hemorrhage (OR 1.014, P = 0.016), which was more pronounced in men (OR 1.027, P = 0.002). Increased hemoglobin was independently associated with basal ganglia hemorrhage and lobar hemorrhage in men (OR 0.986, P = 0.022; OR 1.013, P = 0.044, respectively) but not in women (P > 0.1). CONCLUSIONS: Increased hemoglobin was independently associated with large hemorrhage volume. Increased hemoglobin was independently associated with lobar hemorrhage in men and ICH with subarachnoid hemorrhage, which was more pronounced in men. Additional studies are needed to confirm our findings and explore potential mechanisms.


Asunto(s)
Hemorragia Subaracnoidea , Hemorragia Cerebral , Femenino , Hematoma/epidemiología , Hemoglobinas , Humanos , Masculino , Estudios Retrospectivos
4.
J Environ Manage ; 323: 116183, 2022 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-36088763

RESUMEN

Membrane bioreactor with the floc activated sludge (mixed liquor suspended solids (MLSS) = 7500 mg/L) was constructed in this work for simultaneously nitrification and denitrification (SND). The effect of dissolved oxygen (DO) on SND process and the nitrogen pathways were investigated. The average TN removal efficiencies were 63.05%, 91.17%, 87.04% and 70.02% for DO 0.5, 1, 2 and 3 mg/L systems, respectively. The effluent ammonia concentration was continuously lower than 5.0 mg/L when the DO was higher than 1 mg/L. Nitrogen in DO 1 and DO 2 mg/L systems was mainly removed via the SND process. The rise of DO concentration increased the abundance of nitrite oxidizing bacteria (NOB) and Nitrospira was the predominant NOB in all the four MBRs. Dechloromonas and Azoarcus were the dominant denitrifying bacteria (DNB) in DO 1 systems responsible for nitrite denitrification. The dominant aerobic DNB Pseudomonas also contributed SND via nitrate denitrification and was little affected by DO changes. Nitrate reductase was the main enzyme for the reduction of NO3--N to NO2--N, and narG was the main responsible gene. Nitrite oxidoreductase was the main enzyme for the oxidation of NO2--N to NO3--N, and nxrA was the main responsible gene in all the four MBR systems.


Asunto(s)
Desnitrificación , Nitrificación , Amoníaco/metabolismo , Bacterias/metabolismo , Reactores Biológicos/microbiología , Nitratos/metabolismo , Nitritos , Nitrógeno/metabolismo , Dióxido de Nitrógeno , Oxidorreductasas/metabolismo , Oxígeno/metabolismo , Aguas del Alcantarillado/microbiología , Aguas Residuales/microbiología
5.
Appl Energy ; 317: 119136, 2022 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-35492379

RESUMEN

Global carbon emissions have been rapidly increasing in recent years, negatively influencing the global climate. Thereby, it is urgent to reduce carbon emissions and achieve carbon neutrality. During the COVID-19 pandemic, strict quarantine plans have led to a sharp decline in the number of international student flights, which will, in turn, decrease aviation carbon emissions. This study predicts the carbon emission reduction caused by the decrease in international student mobility during the COVID-19. The result shows that the carbon emission was about 1326 Gg, a staggering value equivalent to two-thirds of the carbon emissions of the UK's agriculture sector in a year. Furthermore, this study analyzes the implications of current mitigation policies and makes recommendations for future strategies.

6.
J Environ Sci (China) ; 113: 152-164, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-34963525

RESUMEN

Ultraviolet (UV) assisted zero-valent iron (ZVI)-activated sodium persulfate (PDS) oxidation (UV-ZVI-PDS) was used to treat waste activated sludge (WAS) in this study. The dewaterability performance and mechanism of WAS dewatering were analyzed. The results showed that UV-ZVI-PDS can obtain better sludge dewatering performance in a wide pH range (2.0-8.0). When the molar ratio of ZVI/PDS was 0.6, UV was 254nm, PDS dosage was 200 mg/g TS (total solid), pH was 6.54, reaction time was 20 min, the CST (capillary suction time) and SRF (specific resistance to filtration) were decreased by 64.0% and 78.2%, respectively. The molar ratio of ZVI/PDS used in this paper is much lower than that of literatures, and the contents of total Fe and Fe2+ in sludge supernatant remained at a low level, as 3.7 mg/L and 0.0 mg/L. The analysis of extracellular polymeric substances (EPS), scanning electron microscope (SEM) and particle size distribution showed that the EPS could be effectively destroyed by UV-ZVI-PDS, the sludge flocs broken down into smaller particles, cracks and holes appeared, and then the bound water was released. At the same time, the highly hydrophilic tightly bound-EPS (TB-EPS) were converted into loosely bound EPS (LB-EPS) and soluble EPS (S-EPS). During sludge pretreated by UV-ZVI-PDS, positively charged ions, such as Fe2+, Fe3+ and H+, produced in the reaction system could reduce the electronegativity of sludge surface, promote sludge particles aggregation, and then enhanced the sludge dewaterability.


Asunto(s)
Hierro , Aguas del Alcantarillado , Matriz Extracelular de Sustancias Poliméricas , Filtración , Oxidación-Reducción , Eliminación de Residuos Líquidos , Agua
7.
Zhongguo Zhong Yao Za Zhi ; 47(6): 1642-1649, 2022 Mar.
Artículo en Zh | MEDLINE | ID: mdl-35347963

RESUMEN

This study investigated the effects and mechanisms of 6-gingerol on adipose tissue insulin resistance in naturally aging rats with glycolipid metabolism disorders. Twenty-seven aging male SD rats were randomly divided into a model group(aged, n=9) and two groups treated with 6-gingerol at 0.05 mg·kg~(-1)(G-L, n=9) and 0.2 mg·kg~(-1)(G-H, n=9). Six young rats were randomly assigned to a normal control group(NC). Rats were treated for seven weeks by gavage. Non-esterified fatty acid(NEFA) and insulin content was determined by enzyme-linked immunosorbent assay(ELISA), and adipose tissue insulin resistance index(Adipo-IR) was calculated. HE staining was used to observe the size of adipocytes in epididymal white adipose tissue(eWAT). The gene and protein expression levels of adiponectin receptor 1(AdipoR1), AMP-activated protein kinase α(AMPKα), phosphorylated AMPK(p-AMPKα~(Thr172)), peroxisome proliferator-activated receptor-γ coactivator-1α(PGC-1α), phosphatidylinositol 3-kinase(PI3 K), protein kinase B(Akt), phosphorylated Akt(p-Akt~(Ser473)), tumor necrosis factor-α(TNF-α), c-Jun N-terminal kinase 1/2(JNK1/2), phosphorylated JNK1/2(p-JNK~(Thr183/Tyr185)), interleukin-1ß(IL-1ß), and interleukin-6(IL-6) in adiponectin(APN), insulin, and inflammatory factor signaling pathways were detected by Western blot and real-time RCR, respectively. The results showed that 6-gingerol at a high dose could significantly decrease the fasting plasma content of NEFA and insulin and reduce Adipo-IR. Additionally, 6-gingerol at a high dose significantly increased the protein and mRNA expression of APN, AdipoR1, PGC-1α, and PI3 K in eWAT, elevated the relative expression of p-AMPK~(Thr172) and p-Akt~(Ser 473), reduced the protein and mRNA expression of TNF-α, IL-1, and IL-6 in eWAT, and decreased the relative expression of p-JNK1 and p-JNK2. This study reveals that 6-gingerol can improve insulin sensitivity of adipose tissues in aging rats with glycolipid metabolism disorders, and this effect is presumedly achieved by enhancing the PI3 K/Akt signaling pathway, inhibiting adipose tissue inflammation, increasing APN synthesis, enhancing AdipoR1 expression, and activating its downstream AMPK/PGC-1α signaling pathway.


Asunto(s)
Resistencia a la Insulina , Tejido Adiposo , Envejecimiento , Animales , Catecoles , Alcoholes Grasos , Masculino , Ratas , Ratas Sprague-Dawley
8.
Nanotechnology ; 31(46): 465502, 2020 Nov 13.
Artículo en Inglés | MEDLINE | ID: mdl-32575085

RESUMEN

Porous functional materials play important roles in a wide variety of growing research and industrial fields. We herein report a simple, effective method to prepare porous functional graphene composites for multi-field applications. Graphene sheets were non-chemically modified by Triton®X-100, not only to maintain high structural integrity but to improve the dispersion of graphene on the pore surface of a sponge. It was found that a graphene/sponge nanocomposite at 0.79 wt.% demonstrated ideal electrical conductivity. The composite materials have high strain sensitivity, stable fatigue performance for 20 000 cycles, short response time of 0.401 s and fast response to temperature and pressure. In addition, the composites are effective in monitoring materials deformation and acoustic attenuation with a maximum absorption rate 67.78% and it can be used as electrodes for a supercapacitor with capacitance of 18.1 F g-1. Moreover, no expensive materials or complex equipment are required for the composite manufacturing process. This new methodology for the fabrication of multifunctional, durable and highly conductive graphene/sponge nanocomposites hold promise for many other applications.

9.
Environ Sci Technol ; 54(13): 8464-8472, 2020 07 07.
Artículo en Inglés | MEDLINE | ID: mdl-32519855

RESUMEN

Nanocarbon-based persulfate oxidation emerges as a promising technology for the elimination of organic micropollutants (OMPs). However, the nature of the active site and its working mechanism remain elusive, impeding developments of high-performance oxidative technology for water treatment practice. Here, we report that defect-rich carbon nanotubes (CNTs) exhibit a superior activity in the activation of peroxymonosulfate (PMS) for OMP oxidation. Quantitative structure-activity relationship studies combined with theoretical calculations unveil that the double-vacancy defect on CNTs may be the intrinsic active site, which works as a conductive bridge to facilitate the potential difference-dominated electron transfer from the highest occupied molecular orbital of OMPs to the lowest unoccupied molecular orbital of PMS. Based on this unique mechanism, the established CNTs@PMS oxidative system achieves outstanding selectivity and realizes the target-oriented elimination of specific OMPs in a complicated aquatic environment. This work sheds new light on the mechanism of carbocatalysis for selective oxidation and develops an innovative technology toward remediation of practical wastewater.


Asunto(s)
Nanotubos de Carbono , Purificación del Agua , Transporte de Electrón , Electrones , Oxidación-Reducción
10.
Environ Res ; 188: 109692, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32512373

RESUMEN

Activation of peroxydisulfate (PDS) by Fe2+ has been considered as an effective activation method to generate reactive oxygen species (ROS). However, the process is limited for the low production yield of ROS owing to the inefficient Fe3+/Fe2+ cycle. Herein, we demonstrated that Fe2+/PDS system in the presence of molybdenum sulfide (MoS2) was significantly efficient for the degradation of sulfisoxazole (SIX). As a co-catalyst in the Fe2+/PDS system, MoS2 could greatly enhance the Fe3+/Fe2+ cycle by the exposed Mo4+ active sites, which could also improve the PDS decomposition efficiency. As a result, the degradation efficiency of SIX in the MoS2/Fe2+/PDS system could reach to as high as 97.1% within 40 min, which was in distinct comparison with the 45.5% achieved by Fe2+/PDS system without MoS2. Besides, effects of various reaction conditions on SIX degradation were also evaluated during the experiments, including the dosages of MoS2, Fe2+, PDS and initial solution pH and the coexisting inorganic anions. In addition, both of sulfate radicals and hydroxyl radicals were identified as the dominant active species for SIX degradation by the radical scavenging experiments and verified by electron paramagnetic resonance (EPR). This study provides a promising idea for the degradation of organic contaminants in water treatment based on Fe2+/PDS process.


Asunto(s)
Sulfisoxazol , Purificación del Agua , Aceleración , Molibdeno , Oxidación-Reducción
11.
Environ Res ; 183: 109240, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-32062486

RESUMEN

In this work, the interactions and adsorption mechanisms of Cu2+, Cd2+, and Ni2+ on boron nitride (BN) were tested by the simultaneous removal of metal ions from synthetic wastewater. BN was characterized using XRD, SEM, and FTIR spectroscopy. The adsorption differences between BN and the metal ions were explored through comparative studies in a single and ternary system. In the ternary system, adsorption occurs rapidly in the first 2 min for the metal ions, and the affinity order follows Cu2+>Cd2+>Ni2+. However, adsorption behavior changes due to the interaction between metal ions in the ternary system. Cu2+ showed an antagonistic effect on the adsorption of Cd2+ and Ni2+, while Cd2+ and Ni2+ produced a synergistic effect on Cu2+. In addition, the effect of metal ion concentration on the interaction between ions was studied based on a surface response experiment. An increase in Ni2+ or Cd2+ concentrations plays a synergistic effect on the adsorption of Cu2+, while an antagonistic adsorption for Ni2+ occurred with increasing Cu2+ or Cd2+ concentrations. We also discussed the various adsorption mechanisms as complexation, ion exchange, and electrostatic adsorption based on XPS analysis.


Asunto(s)
Metales Pesados , Contaminantes Químicos del Agua , Adsorción , Compuestos de Boro , Concentración de Iones de Hidrógeno , Metales Pesados/química , Aguas Residuales
12.
Sensors (Basel) ; 20(2)2020 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-31936007

RESUMEN

Although graphene has been widely used as a nano-filler to enhance the conductivity of porous materials, it is still an unsatisfactory requirement to prepare graphene-based sponge porous materials by simple and low-cost methods to enhance their mechanical properties and make them have good sensing and capacitive properties. Graphene platelets (GnPs) were prepared by the thermal expansion method. Graphene-based sponge porous materials were prepared by a simple method. A flexible sensor was formed and supercapacitors were assembled. Compared with other graphene-based composites, the graphene-based composite sponge has good electrical response under bending and torsion loading. Under 180° bending and torsion loading, the maximum resistance change rate can reach 13.9% and 52.5%, respectively. The linearity under tension is 0.01. The mechanical properties and capacitance properties of the sponge nanocomposites were optimized when the filler fraction was 1.43 wt.%. The tensile strength was 0.236 MPa and capacitance was 21.4 F/g. In cycles, the capacitance retention rate is 94.45%. The experimental results show that the graphene-based sponge porous material can be used as a multifunctional flexible sensor and supercapacitor, and it is a promising and multifunctional porous nanocomposite material.

13.
Environ Sci Technol ; 53(8): 4371-4379, 2019 04 16.
Artículo en Inglés | MEDLINE | ID: mdl-30888808

RESUMEN

This study reports a novel intrabridging strategy to improve the antifouling performance of a thin-film composite (TFC) membrane. We demonstrate that the addition of Ca2+ during the interfacial polymerization reaction led to the formation of stable Ca2+-carboxyl complexes within the polyamide rejection layer. This intrabridging of carboxyl groups by Ca2+ effectively sequestrated them, reducing their availability for binding divalent metal ions in the aqueous solution and for forming foulant-metal-membrane interbridges. Membrane fouling and cleaning experiments confirmed improved flux stability and fouling reversibility for the Ca2+ modified membranes. The greatly enhanced antifouling performance of these membranes, together with their better surface hydrophilicity and greater water permeability, makes the intrabridging approach highly attractive in overcoming the classical permeability-selectivity-antifouling trade-off. Our findings pave a new direction for synthesizing high-performance TFC membranes.


Asunto(s)
Calcio , Membranas Artificiales , Nylons , Ósmosis , Polimerizacion
14.
Environ Sci Technol ; 52(2): 765-774, 2018 01 16.
Artículo en Inglés | MEDLINE | ID: mdl-29251922

RESUMEN

In this study, in situ pretreatments with ozone and Fe(II)/persulfate were employed to suppress membrane fouling during the filtration of algae-laden water and to improve the rejection of metabolites. Both ozonation and Fe(II)/persulfate pretreatments negatively impacted the cell integrity, especially ozonation. Fe(II)/persulfate pretreatment improved the removal of dissolved organic carbon and microcystin-LR, but ozonation resulted in a deterioration in the quality of the filtered water. This suggests that the Fe(II)/persulfate oxidation is selective for organic degradation over cell damage. With ozonation, 2-methylisoborneol and geosmin were detected in the filtered water, and the irreversible fouling increased. The intracellular organic release and generation of small organic compounds with ozonation may be the reason for the increased membrane fouling. Fe(II)/persulfate oxidation substantially mitigated the membrane-fouling resistance at concentrations over 0.2 mM compared to the membrane-fouling resistance without oxidation. The combined effect of oxidation and coagulation is likely the reason for the excellent fouling control with Fe(II)/persulfate pretreatment. Membrane fouling during the filtration of algae-laden water is successively governed by complete-blocking and cake-filtration mechanisms. Ozonation caused a shift in the initial major mechanism to intermediate blocking, and the Fe(II)/persulfate pretreatment (>0.2 mM) converted the dominant mechanism into single-standard blocking.


Asunto(s)
Ozono , Purificación del Agua , Compuestos Ferrosos , Membranas Artificiales , Ultrafiltración
15.
J Environ Sci (China) ; 45: 215-23, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27372136

RESUMEN

Three-dimensional fluorescence excitation-emission matrix (EEM) coupled with parallel factor analysis (PARAFAC) was performed for a total of 18 water samples taken from three water sources (two lakes and one wastewater treatment plant (WWTP) secondary effluent), with the purpose of identifying the major ultrafiltration (UF) membrane foulants in different water sources. Three fluorescent components (C1, C2 and C3) were identified, which represented terrestrially derived humic-like substances (C1), microbially derived humic-like substances (C2), and protein-like substances (C3). The correlations between the different fluorescent components and UF membrane fouling were analyzed. It was shown that for the WWTP secondary effluent, all three components (C1, C2 and C3) made a considerable contribution to the irreversible and total fouling of the UF membrane. However, for the two lakes, only the C3 exhibited a strong correlation with membrane fouling, indicating that the protein-like substances were the major membrane foulants in the lake waters. Significant attachment of C1, C2 and C3 to the UF membrane was also confirmed by mass balance analyses for the WWTP secondary effluent; while the attachment of C1 and C2 was shown to be negligible for the two lakes. The results may provide basic formation for developing suitable fouling control strategies for sustainable UF processes.


Asunto(s)
Colorantes/análisis , Membranas Artificiales , Ultrafiltración/métodos , Eliminación de Residuos Líquidos/métodos , Fluorescencia
16.
Bioresour Technol ; 393: 130013, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37956947

RESUMEN

Currently, severe membrane fouling and inefficient nitrogen removal were two main issues that hindered the sustainable operation and further application of membrane bioreactor (MBR). This study aimed to simultaneously alleviate membrane fouling and improve nitrogen removal by applying high sludge concentration in MBR. Results showed that high sludge concentration (12000 mg/L) enhanced total nitrogen removal efficiency (78 %) and reduced transmembrane pressure development rate. Microbial community analysis revealed that high sludge concentration enriched functional bacteria associated with nitrogen removal, increased filamentous bacteria fraction in bio-cake and inhibited Thiothrix overgrowth in bulk sludge. From molecular level, the key genes involved in nitrogen metabolism, electron donor/adenosine triphosphate production and amino acid degradation were up-regulated under high sludge concentration. Overall, high sludge concentration improved microbial assembly and functional gene abundance, which not only enhanced nitrogen removal but also alleviated membrane fouling. This study provided an effective strategy for sustainable operation of MBR.


Asunto(s)
Incrustaciones Biológicas , Aguas del Alcantarillado , Aguas del Alcantarillado/microbiología , Nitrificación , Incrustaciones Biológicas/prevención & control , Desnitrificación , Metagenoma , Reactores Biológicos/microbiología , Nitrógeno , Membranas Artificiales
17.
Sci Total Environ ; 912: 168834, 2024 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-38036125

RESUMEN

Atmosphere is an important component of the microplastics (MPs) cycle. However, studies on atmospheric MPs in peri-urban farmland ecosystems are limited. Herein, the occurrence, influencing factors and geographic sources of atmospheric MPs in peri-urban farmland ecosystems have been analyzed. The average deposition flux of atmospheric MPs was found to be 167.09 ± 92.03 item·m-2·d-1. Around 68 % MPs had particle size <1000 µm, while the main colors of MPs were black (40.71 %) and blue (20.64 %). Approximately 91 % MPs were fibers, while polyethylene terephthalate (49 %) and rayon (36.93 %) were observed as the major microplastic types. The main factors influencing the atmospheric deposition of MPs were gross domestic product (GDP), population density, air pressure, and wind direction. Deposition fluxes exhibited positive correlations with GDP, population density and air pressure, and negative correlations with wind direction. Combined with the backward trajectory model, MPs were mainly found to be originated from the southeast in September and from the northwest in October-February. The study of atmospheric MPs in farmland ecosystems in peri-urban areas is important for the protection of ecological environment, prevention of human diseases and control of MPs pollution.


Asunto(s)
Microplásticos , Contaminantes Químicos del Agua , Humanos , Beijing , Plásticos , Ecosistema , Granjas , China , Monitoreo del Ambiente
18.
J Hazard Mater ; 466: 133584, 2024 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-38286047

RESUMEN

Reactive electrochemical membrane (REM) emerges as an attractive strategy for the elimination of refractory organic pollutants that exist in wastewater. However, the limited reaction sites in traditional REMs greatly hinder its practical application. Herein, a feed-through coating methodology was developed to realize the uniform loading of SnO2-Sb catalysts on the interior surface of a REM. The uniformly coated REM (Unif-REM) exhibited 2.4 times higher reaction kinetics (0.29 min-1) than that of surface coated REM (Surf-REM) for the degradation of 2 mM 4-chlorophenol (4-CP), rendering an energy consumption as low as 0.016 kWh gTOC-1. The fast degradation of various emerging contaminants, e.g., sulfamethoxazole (SMX), ofloxacin (OFLX), and tetracycline (TC), also confirms its superior oxidation capability. Besides, the Unif-REM exhibited good performance in generating hydroxyl radicals (•OH) and a relatively long service lifetime. The simulation of spatial current distribution demonstrates that the interior reaction region in the Unif-REM channels can be drastically extended, thereby maximizing the surface coupling of mass diffusion and electron transfer. This study offers an in-depth look at the spatially confined reactions in REM and provides a reference for the design of electrochemical systems with economically efficient water purification.

19.
Bioresour Technol ; : 131051, 2024 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-38944315

RESUMEN

Strengthening the direct interspecies electron transfer (DIET) is an effective strategy to improve the performance of anaerobic digestion (AD) process. In this study, the polyaniline functionated activated carbon (AC-PANi) was prepared by chemical oxidative polymerization. This material possessed pseudo-capacitance properties as well as excellent charge transfer capability. The experimental results demonstrated that the incorporation of AC-PANi in AD process could efficiently increase the chemical oxygen demand (COD) removal (18.6 %) and daily methane production rate (35.3 %). The AC-PANi can also act as an extracellular acceptor to promote the synthesis of adenosine triphosphate (ATP) and secretion of extracellular enzymes as well as cytochrome C (Cyt-C). The content of coenzyme F420 on methanogens was also shown to be increased by 60.9 % with the addition of AC-PANi in AD reactor. Overall, this work provides an easy but feasible way to enhance AD performance by promoting DIET between acetate-producing bacteria and methanogens.

20.
Water Res ; 257: 121745, 2024 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-38733965

RESUMEN

Polyester-amide (PEA) thin film composite (TFC) NF membranes have rapidly evolved towards a competitive performance, benefiting from their remarkable antifouling capability and superior chlorine resistance. In this report, a new concept of synergistic interfacial polymerization is explored, which promptly triggers the reaction between hydramines and trimesoyl chloride (TMC) in the presence of a trace amount of diamines. This rapid-start mode enables the formation of defect-free PEA films without the requirement of catalysis. A comprehensive characterization of physicochemical properties using high-resolution mass spectrometer (HRMS) reveals that the recombination and formation of a "hydramine-diamine" coupling unit plays a decisive role in activating the synergistic interfacial polymerization reaction with TMC molecules. Taking the pair of serinol and piperazine (PIP) as an example, the PEA-NF membrane fabricated with 0.1 w/v% serinol mixed with 0.04 w/v% PIP as water-soluble monomer and 0.1 w/v% TMC as oil phase monomer was found to have a pure water permeability (PWP) of 18.5 L·m-2·h-1·bar-1 and a MgSO4 rejection of 95.5 %, which surpasses almost all the reported PEA NF membranes. Findings of the current research provide more possibilities for the low-cost and rapid synthesis of high-performance PEA membranes aiming for water purification.


Asunto(s)
Membranas Artificiales , Polimerizacion , Diaminas/química , Poliésteres/química
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