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1.
Water Sci Technol ; 90(1): 256-269, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-39007318

RESUMEN

Palladium is now frequently utilized in fuel cells, electroplating, electronics, and catalysis. Due to their rarity and high cost, precious metal recovery has taken on a significant role. The extraction method frequently utilized in polymer inclusion membranes (PIMs) is both efficient and simple since it has been demonstrated that precious metal adsorption on the membrane significantly controls the mechanism of chemical adsorption. In this study, polyvinyl chloride (PVC) as a polymer, A336 as a plasticizer, and trioctylamine (TOA) as a carrier were used to produce a PIM by evaporation. After the production of PIMs, palladium extract was studied. The stripping phase, palladium concentration in the feed phase, and components of the membrane were changed to determine the optimum condition with better extraction ability. When 0.5 M of HCl was used, higher kinetic parameter results and higher than 85% extraction efficiency were achieved compared to other concen- trations. When the EDX results were examined, 3.3% palladium was retained on the membrane surface. When the palladium concentration was selected at 2.5 ppm, higher kinetic parameters were observed, and the extraction efficiency was over 90%. The best membrane was the PIM containing 40% PVC-40% A336-20% TOA.


Asunto(s)
Membranas Artificiales , Paladio , Paladio/química , Polímeros/química , Cloruro de Polivinilo/química , Contaminantes Químicos del Agua/química
2.
Environ Sci Technol ; 58(28): 12621-12632, 2024 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-38954776

RESUMEN

The majority of microplastics (MPs) found in the environment originate from plastic fragmentation occurring in the environment and are influenced by environmental factors such as UV irradiation and biotic interactions. However, the effects of river drying on plastic fragmentation remain unknown, despite the global prevalence of watercourses experiencing flow intermittence. This study investigates, through laboratory experiments, the coupled effects of drying duration and UV irradiation on PVC film fragmentation induced by artificial mechanical abrasion. This study shows that PVC film fragmentation increases with drying duration through an increase in the abundance and size of formed MPs as well as mass loss from the initial plastic item, with significant differences for drying durations >50% of the experiment duration. The average abundance of formed MPs in treatments exposed to severe drying duration was almost two times higher than in treatments nonexposed to drying. Based on these results, we developed as a proof of concept an Intermittence-Based Plastic Fragmentation Index that may provide insights into plastic fragmentation occurring in river catchments experiencing large hydrological variability. The present study suggests that flow intermittence occurring in rivers and streams can lead to increasing plastic fragmentation, unraveling new insights into plastic pollution in freshwater systems.


Asunto(s)
Microplásticos , Cloruro de Polivinilo , Ríos , Ríos/química , Cloruro de Polivinilo/química , Contaminantes Químicos del Agua , Rayos Ultravioleta , Monitoreo del Ambiente , Desecación
3.
Environ Sci Technol ; 58(26): 11542-11553, 2024 Jul 02.
Artículo en Inglés | MEDLINE | ID: mdl-38871676

RESUMEN

Nanoplastics (NPs) are emerging pollutants and have been reported to cause the disintegration of anaerobic granular sludge (AnGS). However, the mechanism involved in AnGS disintegration was not clear. In this study, polyvinyl chloride nanoplastics (PVC-NPs) were chosen as target NPs and their long-term impact on AnGS structure was investigated. Results showed that increasing PVC-NPs concentration resulted in the inhibition of acetoclastic methanogens, syntrophic propionate, and butyrate degradation, as well as AnGS disintegration. At the presence of 50 µg·L-1 PVC-NPs, the hydrophobic interaction was weakened with a higher energy barrier due to the relatively higher hydrophilic functional groups in extracellular polymeric substances (EPS). PVC-NPs-induced ROS inhibited quorum sensing, significantly downregulated hydrophobic amino acid synthesis, whereas it highly upregulated the genes related to the synthesis of four hydrophilic amino acids (Cys, Glu, Gly, and Lys), resulting in a higher hydrophily degree of protein secondary structure in EPS. The differential expression of genes involved in EPS biosynthesis and the resulting protein secondary structure contributed to the greater hydrophilic interaction, reducing microbial aggregation ability. The findings provided new insight into the long-term impact of PVC-NPs on AnGS when treating wastewater containing NPs and filled the knowledge gap on the mechanism involved in AnGS disintegration by PVC-NPs.


Asunto(s)
Matriz Extracelular de Sustancias Poliméricas , Cloruro de Polivinilo , Aguas del Alcantarillado , Aguas del Alcantarillado/microbiología , Cloruro de Polivinilo/química , Matriz Extracelular de Sustancias Poliméricas/metabolismo , Anaerobiosis , Interacciones Microbianas
4.
J Phys Chem Lett ; 15(25): 6560-6567, 2024 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-38885454

RESUMEN

Aggregation of human α-synuclein protein is regarded to be a key stage in the etiology of Parkinson's disease and numerous other neurodegenerative illnesses. Microplastics pollution can be a potential agent to promote various neurodegenerative disorders. In this study, we have employed various multispectroscopic analytical methods to investigate the binding interactions between polyethylene (PE-MPs), polyvinyl chloride (PVC-MPs), polystyrene (PS-MPs) microplastics, and human α-synuclein protein. Spectroscopic investigations using UV-vis absorption, circular dichroism, and Fourier transform infrared have indicated different alterations in α-synuclein protein's secondary structures induced by the formation of the α-synuclein protein-MP binding complex. This study suggests that PS-MPs are found to be the most effective microplastic that promote amyloidogenic oligomer emergence because of their tiny size (100 nm).


Asunto(s)
Microplásticos , alfa-Sinucleína , alfa-Sinucleína/química , alfa-Sinucleína/metabolismo , Humanos , Microplásticos/química , Poliestirenos/química , Dicroismo Circular , Espectroscopía Infrarroja por Transformada de Fourier , Unión Proteica , Cloruro de Polivinilo/química , Polietileno/química , Estructura Secundaria de Proteína , Amiloide/química , Amiloide/metabolismo
5.
Anal Chem ; 96(25): 10434-10442, 2024 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-38866710

RESUMEN

Plasma protein adsorption on blood-contacting surfaces is the initiating significant event and modulates the subsequent coagulation response. Despite decades of research in this area, Vroman's questions in 1986 "Who gets there first?" and "When does the next protein arrive?" remain unanswered due to the lack of detection techniques with sufficient temporal resolution. In this work, we develop a droplet microfluidic technology to detect protein adsorption sequences on six typical blood-contacting surfaces in milliseconds. Apolipoproteins (Apo) are found to be the first proteins to adsorb onto the surfaces in a plasma droplet, and the specific type of apolipoprotein depends on the surface. Apo CI is the first protein adsorbed on gold, platinum, graphene, stainless steel, and polyvinyl chloride with the adsorption time varying from 0.01 to 1 s, while Apo CIII preferentially reaches the titanium alloy surface within 1 s. Subsequent to the initial adsorption, Apo AI, AII, and other proteins continue to adsorb until albumin arrives. Thus, the adsorption sequence is revealed, and Vroman's questions are answered. Moreover, this finding demonstrates the influence of the initial protein adsorption on subsequent coagulation at the surface, and it offers new insights into the development of anticoagulant surfaces.


Asunto(s)
Propiedades de Superficie , Adsorción , Humanos , Proteínas Sanguíneas/química , Proteínas Sanguíneas/metabolismo , Oro/química , Acero Inoxidable/química , Grafito/química , Apolipoproteínas/química , Cloruro de Polivinilo/química , Platino (Metal)/química , Técnicas Analíticas Microfluídicas , Titanio/química
6.
STAR Protoc ; 5(2): 103104, 2024 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-38861383

RESUMEN

Approaches for detecting micro(nano)plastics (MNPs) released from intravenous infusion products (IVIPs) are vital for evaluating the safety of both IVIPs and their derived MNPs on human health, yet current understanding is limited. Here, we present a protocol for detecting polyvinyl chloride (PVC) MNPs by combining Raman spectroscopy, scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy (SEM-EDS), and pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS). We describe steps for collecting, pretreating, and measuring PVC MNPs released from IVIPs. For complete details on the use and execution of this protocol, please refer to Li et al.1.


Asunto(s)
Espectrometría Raman , Espectrometría Raman/métodos , Infusiones Intravenosas , Cromatografía de Gases y Espectrometría de Masas/métodos , Cloruro de Polivinilo/química , Humanos , Microscopía Electrónica de Rastreo/métodos , Espectrometría por Rayos X/métodos , Plásticos/química
7.
Sci Rep ; 14(1): 13051, 2024 06 06.
Artículo en Inglés | MEDLINE | ID: mdl-38844516

RESUMEN

In this work, the surface of polyvinyl chloride PVC sheet was modified by blending it with sunflower seed oil SSO to obtain PVC sheet/SSO films of ratios 100/0, 90/10, 80/20, 70/30, 60/40, and 50/50 (v/v)% using the solution casting method. Various techniques were used to characterize the prepared films, besides the use of hemolysis assays and blood clot formation tests. FTIR spectra revealed that there was a good interaction between the PVC sheet and the oil. The dielectric measurement indicated that SSO addition enhanced the dielectric properties of the sheet. The study of dielectric relaxation times confirmed the interaction between SSO and the sheet. DC conductivity increased to 6 × 10-6 S/m, so it could be applied in antistatic applications. Also, SSO addition increased the value of the thermal stability. According to SEM micrographs, the film was roughened at a ratio of 60/40 and smoothed out at 50/50. This behavior was confirmed with roughness and contact angle measurement results, in which the film of ratio 60/40 had the highest value equal to (72.03°) and then decreased at 50/50 to (59.62°). These results were confirmed by XRD measurement as the crystallinity increased at the film ratio of 60/40 and decreased again at 50/50. Also, the ratio of 60/40 demonstrated a large decrease in thrombus weights along with a slight increase in hemolysis, which is within the acceptable range and has a high degree of biocompatibility, so this concentration is recommended to be used in blood bags applications.


Asunto(s)
Hemólisis , Cloruro de Polivinilo , Aceite de Girasol , Aceite de Girasol/química , Cloruro de Polivinilo/química , Hemólisis/efectos de los fármacos , Espectroscopía Infrarroja por Transformada de Fourier , Humanos , Animales , Coagulación Sanguínea/efectos de los fármacos , Propiedades de Superficie , Aceites de Plantas/química
8.
Chemosphere ; 361: 142577, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38857632

RESUMEN

Water distribution networks play a crucial role in ensuring a reliable water supply, yet they encounter challenges such as corrosion, scale formation, and biofilm growth due to interactions with environmental elements. Biofilms and corrosion layers are significant contaminants in water pipes, formed by complex interactions with pipe materials. As the structure of these contamination layers varies depending on the pipe material, it is essential to investigate the contamination layer for each material individually. Specifically, biofilm growth is typically investigated concerning organic sources, while the growth of humus layers is examined in relation to inorganic elements such as manganese (Mn), iron (Fe), and aluminum (Al), which are major elements and organic substances found in water pipes. Real-time imaging of recently contaminated layers can provide important insights to improve system performance by optimizing operations and cleaning processes. In this study, cast iron (7.10 ± 0.78 nm) exhibits greater surface roughness compared to PVC (5.60 ± 0.14 nm) and provides favorable conditions for biofilm formation due to its positive charge. Over a period of 425 h, the fouling layer on cast iron and PVC surfaces gradually increased in fouling thickness, porosity, roughness, and density, reaching maximum value of 29.72 ± 3.6 µm, 11.44 ± 1.1%, 41673 ± 1025.6 pixels, and 0.80 ± 0.3 fouling layer pixel/layer pixel for cast iron, and 8.15 ± 0.4 µm, 20.64 ± 0.9%, 35916.6 ± 755.7 pixels, and 0.58 ± 0.1 fouling layer pixel/layer pixel, respectively. Within the scope of the current research, CNN model demonstrates high correlation coefficients (0.98 and 0.91) in predicting biofilm thickness for cast iron and PVC. The model also presented high accuracy in predicting porosity for both materials (over 0.91 for cast iron and 0.96 for PVC). While the model accurately predicted biofilm roughness and density for cast iron (correlation coefficients 0.98 and 0.94, respectively), it had lower accuracy for PVC (correlation coefficients 0.92 for both parameters).


Asunto(s)
Biopelículas , Hierro , Abastecimiento de Agua , Biopelículas/crecimiento & desarrollo , Corrosión , Hierro/química , Hierro/análisis , Monitoreo del Ambiente/métodos , Aluminio/química , Cloruro de Polivinilo/química
9.
Waste Manag ; 183: 21-31, 2024 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-38714119

RESUMEN

Poly(vinyl chloride) (PVC) is one of the most widely used plastics. However, a major challenge in recycling PVC is that there is no economical method to separate and remove its toxic phthalate plasticizers. This research made a breakthrough by extracting PVC with liquefied dimethyl ether (DME) and successfully separating the plasticizer components. Nearly all (97.1 %) of the di(2-ethylhexyl) phthalate plasticizer was extracted within 30 min by passing liquefied DME (285 g) through PVC at 25 °C. The compatibility of PVC with organic solvents, including liquefied DME, was derived theoretically from their Hansen solubility parameters (HSP), and actual dissolution experiments were conducted to determine the optimal PVC solvents. A liquefied DME mixture was used to dissolve PVC, and the extract was diluted with ethanol to precipitate the dissolved PVC. We demonstrated that liquefied DME is a promising method for producing high quality recycled products and that the process retains the fundamental properties of plasticizers and PVC without inducing degradation or depolymerization. Because of its low boiling point, DME can be easily separated from the solute after extraction, allowing for efficient reuse of the solvent, extracted plasticizer, and PVC. DME does not require heat and produces little harmful wastewater, which significantly reduces the energy consumption of the plasticizer additive separation process.


Asunto(s)
Dietilhexil Ftalato , Éteres Metílicos , Plastificantes , Cloruro de Polivinilo , Reciclaje , Cloruro de Polivinilo/química , Dietilhexil Ftalato/química , Reciclaje/métodos , Éteres Metílicos/química , Éteres Metílicos/análisis , Solventes/química , Ácidos Ftálicos/química
10.
ACS Appl Mater Interfaces ; 16(19): 24248-24260, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38693878

RESUMEN

Biomedical devices are vulnerable to infections and biofilm formation, leading to extended hospital stays, high expenditure, and increased mortality. Infections are clinically treated via the administration of systemic antibiotics, leading to the development of antibiotic resistance. A multimechanistic strategy is needed to design an effective biomaterial with broad-spectrum antibacterial potential. Recent approaches have investigated the fabrication of innately antimicrobial biomedical device surfaces in the hope of making the antibiotic treatment obsolete. Herein, we report a novel fabrication strategy combining antibacterial nitric oxide (NO) with an antibiofilm agent N-acetyl cysteine (NAC) on a polyvinyl chloride surface using polycationic polyethylenimine (PEI) as a linker. The designed biomaterial could release NO for at least 7 days with minimal NO donor leaching under physiological conditions. The proposed surface technology significantly reduced the viability of Gram-negative Escherichia coli (>97%) and Gram-positive Staphylococcus aureus (>99%) bacteria in both adhered and planktonic forms in a 24 h antibacterial assay. The composites also exhibited a significant reduction in biomass and extra polymeric substance accumulation in a dynamic environment over 72 h. Overall, these results indicate that the proposed combination of the NO donor with mucolytic NAC on a polymer surface efficiently resists microbial adhesion and can be used to prevent device-associated biofilm formation.


Asunto(s)
Acetilcisteína , Antibacterianos , Biopelículas , Escherichia coli , Óxido Nítrico , Staphylococcus aureus , Acetilcisteína/química , Acetilcisteína/farmacología , Óxido Nítrico/química , Óxido Nítrico/metabolismo , Óxido Nítrico/farmacología , Staphylococcus aureus/efectos de los fármacos , Escherichia coli/efectos de los fármacos , Antibacterianos/farmacología , Antibacterianos/química , Biopelículas/efectos de los fármacos , Polietileneimina/química , Polietileneimina/farmacología , Materiales Biocompatibles/química , Materiales Biocompatibles/farmacología , Pruebas de Sensibilidad Microbiana , Cloruro de Polivinilo/química , Donantes de Óxido Nítrico/química , Donantes de Óxido Nítrico/farmacología
11.
Anal Methods ; 16(21): 3372-3384, 2024 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-38747244

RESUMEN

Microfluidic channels fabricated over fabrics or papers have the potential to find substantial application in the next generation of wearable healthcare monitoring systems. The present work focuses on the fabrication procedures that can be used to obtain practically realizable fabric-based microfluidic channels (µFADs) utilizing patterning masks and wax, unlike conventional printing techniques. In this study, comparative analysis was used to differentiate channels obtained using different masking tools for channel patterning as well as different wax materials as hydrophobic barriers. Drawbacks of the conventional tape and candle wax technique were noted and a novel approach was used to create microfluidic channels through a facile and simple masking technique using PVC clear sheets as channel stencils and beeswax as the channel barriers. The resulting fabric based microfluidic channels with varying widths as well as complex microchannel, microwell, and micromixer designs were investigated and a minimum channel width resolution of 500 µm was successfully obtained over cotton based fabrics. Thereafter, the PVC clear sheet-beeswax based microwells were successfully tested to confine various organic and inorganic samples indicating vivid applicability of the technique. Finally, the microwells were used to make a simple and facile colorimetric assay for glucose detection and demonstrated effective detection of glucose levels from 10 mM to 50 mM with significant color variation using potassium iodide as the coloring agent. The above findings clearly suggest the potential of this alternative technique for making low-cost and practically realizable fabric based diagnostic devices (µFADs) in contrast to the other approaches that are currently in use.


Asunto(s)
Cloruro de Polivinilo , Textiles , Ceras , Ceras/química , Cloruro de Polivinilo/química , Colorimetría/métodos , Colorimetría/instrumentación , Técnicas Analíticas Microfluídicas/instrumentación , Técnicas Analíticas Microfluídicas/métodos , Análisis Costo-Beneficio , Glucosa/análisis , Dispositivos Laboratorio en un Chip , Humanos , Diseño de Equipo , Dispositivos Electrónicos Vestibles
12.
Chemosphere ; 359: 142283, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38734251

RESUMEN

Polyvinyl chloride (PVC), known for its chemical stability and flame-retardant qualities, has many uses in various fields, such as pipes, electric wires, and cable insulation. Research has established its potential recovery as a fluidic fuel through pyrolysis, but the use of PVC pyrolysis oil, which is tainted by chlorine, is constrained by its low heat value and harmful environmental effects. This study engineered a layered double hydroxide (LDH) to tackle these challenges. The LDH facilitated dechlorination during PVC pyrolysis and bolstered thermal stability via cross-linking. During pyrolysis with LDH, PVC was transformed into carbon-rich precursors to sorbents. Chemical activation of these residues using KOH created sorbents with a specific surface area of 1495.4 m2 g⁻1, rendering them hydrophilic. These resulting sorbents displayed impressive adsorption capabilities, removing up to 486.79 mg g⁻1 of methylene blue and exhibiting the simultaneous removal of cations and anions.


Asunto(s)
Colorantes , Hidróxidos , Cloruro de Polivinilo , Cloruro de Polivinilo/química , Hidróxidos/química , Adsorción , Colorantes/química , Colorantes/aislamiento & purificación , Compuestos de Potasio/química , Contaminantes Químicos del Agua/química , Azul de Metileno/química , Pirólisis
13.
J AOAC Int ; 107(4): 549-557, 2024 Jul 04.
Artículo en Inglés | MEDLINE | ID: mdl-38627224

RESUMEN

BACKGROUND: Through the use of sustainable and green chemistry concepts, scientists need to decrease waste, conserve energy, and develop safe substitutes for hazardous compounds, all for protecting and benefiting society and the environment. OBJECTIVE: Four novel eco-friendly ion selective electrodes (ISE) were generated to determine Ethamsylate (ETM) in bulk powder and different pharmaceutical formulations. The present electrodes were fabricated to clearly distinguish ETM from a variety of inorganic, organic ions, sugars, some common drug excipients and the degradation product, hydroquinone (HQ) of ETM, and thus used for stability-indicating methods. METHODS: The electrodes fabrication was based on 2-nitrophenyl octyl ether (NPOE) that was employed as a plasticizer in electrodes 1, 2, and 3 within a polymeric matrix of polyvinyl chloride (PVC) except for electrode 4, in which dibutyl sebacate was used as a plasticizer. Electrodes 1 and 2 were fabricated using tetradodecylammonium bromide as an anionic exchanger, adding 4-sulfocalix-8-arene as an ionophore only to electrode 2 and preparing electrode 1 without incorporation of an ionophore. The fabrication of electrodes 3 and 4 was based on ethamsylate-tetraphenylborate (ETM-TPB) as an ion-association complex in a PVC matrix. The environmental sustainability was assessed using the green analytical procedure index (GAPI), and analytical greenness metric for sample preparation (AGREEprep). RESULTS: Electrodes 1 and 2 had linear dynamic ranges of 10-1-10-5 mol/L and 10-1-10-4 mol/L, respectively, with a Nernstian slope of 49.6 and 53.2 mV/decade, respectively. Electrodes 3 and 4 had linear dynamic ranges of 10-1-10-4 mol/L, with a Nernstian slope of 43.9 and 40.2 mV/decade, respectively. CONCLUSION: The electrodes' selectivity coefficients showed good selectivity for ETM. The utility of 4-sulfocalix-8-arene as an ionophore had a significant influence on increasing the membrane sensitivity and selectivity of electrode 2 compared to other electrodes. HIGHLIGHTS: Four novel eco-friendly ISEs were used for determination of ETM in bulk powder and different pharmaceutical formulations. Different experimental parameters were performed to optimize the determination conditions such as solvent mediators, dynamic response time, effect of pH, and temperature. Stability-indicating measurement of ETM in the presence of its degradate HQ and co-formulated drug tranexamic acid. Using new ecological assessment tools to determine whiteness and greenness profiles.


Asunto(s)
Electrodos de Iones Selectos , Potenciometría , Potenciometría/métodos , Tecnología Química Verde/métodos , Plastificantes/química , Plastificantes/análisis , Estabilidad de Medicamentos , Cloruro de Polivinilo/química , Éteres
14.
Biopolymers ; 115(4): e23581, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38666470

RESUMEN

The abstract provides an overview of a study focused on analyzing diverse strategies to achieve sustainable utilization of synthetic polymers through effective waste management. The escalating global consumption of synthetic polymers has precipitated a concerning increase in plastic waste and environmental degradation. To address this challenge, novel materials with specified application goals, such as engineered plastic, have been developed and are intended for recycling and reuse. Despite the reuse and recycling, when plastic gets disposed into the environment, the degradation properties of plastics render a direct disposal hazard, posing a significant environmental threat. To mitigate these issues, the concept of replacing specific monomers of engineered synthetic plastics with bio-alternatives or blending them with other polymers to enhance sustainability and environmental compatibility has emerged. In this study, Acrylonitrile Butadiene Styrene (ABS) plastic is the focal material, and three distinct investigations were conducted. First, replacing ABS plastic's butadiene monomer with natural rubber was explored for its properties and environmental impact. Second, ABS plastic was blended with virgin, recycled, and bio-alternatives of PET (polyethylene terephthalate) and PVC (polyvinyl chloride) polymers. Lastly, recycled ABS blended with recycled PET and PVC was analyzed for mechanical properties. Comparative assessments of these blends were made based on mechanical properties, carbon emissions, and cost-effectiveness. The study determined that the r-ABS/r-PVC (recycled) blend exhibited the most favorable characteristics for practical application.


Asunto(s)
Polímeros , Reciclaje , Polímeros/química , Butadienos/química , Plásticos/química , Tereftalatos Polietilenos/química , Cloruro de Polivinilo/química , Administración de Residuos/métodos
15.
J Hazard Mater ; 470: 134167, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38598880

RESUMEN

This study investigated the leaching of phthalate and non-phthalate plasticizers from polyvinyl chloride microplastics (MPs) into sediment and their degradation over a 30-d period via abiotic and biotic processes. The results showed that 3579% of plasticizers were released into the sediment from the MPs and > 99.9% degradation was achieved. Although a significantly higher degradation was found in plasticizer-added microcosms under biotic processes (overall, 94%), there was a noticeable abiotic loss (72%), suggesting that abiotic processes also play a role in plasticizer degradation. Interestingly, when compared with the initial sediment-water partitioning for plasticizers, the partition constants for low-molecular-weight compounds decreased in both microcosms, whereas those for high-molecular-weight compounds increased after abiotic degradation. Furthermore, changes in the bacterial community, abundance of plasticizer-degrading bacterial populations, and functional gene profiles were assessed. In all the microcosms, a decrease in bacterial community diversity and a notable shift in bacterial composition were observed. The enriched potential plasticizer-degrading bacteria were Arthrobacter, Bacillus, Desulfovibrio, Desulfuromonas, Devosia, Gordonia, Mycobacterium, and Sphingomonas, among which Bacillus was recognized as the key plasticizer degrader. Overall, these findings shed light on the factors affecting plasticizer degradation, the microbial communities potentially involved in biodegradation, and the fate of plasticizers in the environment.


Asunto(s)
Bacterias , Sedimentos Geológicos , Microplásticos , Ácidos Ftálicos , Plastificantes , Cloruro de Polivinilo , Contaminantes Químicos del Agua , Cloruro de Polivinilo/química , Plastificantes/metabolismo , Sedimentos Geológicos/microbiología , Sedimentos Geológicos/química , Ácidos Ftálicos/metabolismo , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/metabolismo , Bacterias/metabolismo , Bacterias/clasificación , Biodegradación Ambiental
16.
Water Sci Technol ; 89(8): 2105-2117, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38678412

RESUMEN

Photodynamic processes have found widespread application in therapies. These processes involve photosensitizers (PSs) that, when excited by specific light wavelengths and in the presence of molecular oxygen, generate reactive oxygen species (ROS), that target cells leading to inactivation. Photodynamic action has gained notable attention in environmental applications, particularly against pathogens and antibiotic-resistant bacteria (ARB) that pose a significant challenge to public health. However, environmental matrices frequently encompass additional contaminants and interferents, including microplastics (MPs), which are pollutants of current concern. Their presence in water and effluents has been extensively documented, highlighting their impact on conventional treatment methods, but this information remains scarce in the context of photodynamic inactivation (PDI) setups. Here, we described the effects of polyvinyl chloride (PVC) microparticles in PDI targeting Staphylococcus aureus and its methicillin-resistant strain (MRSA), using curcumin as a PS under blue light. The presence of PVC microparticles does not hinder ROS formation; however, depending on its concentration, it can impact bacterial inactivation. Our results underscore that PDI remains a potent method for reducing bacterial concentrations in water and wastewater containing ARB, even in highly contaminated scenarios with MPs.


Asunto(s)
Staphylococcus aureus Resistente a Meticilina , Microplásticos , Cloruro de Polivinilo , Staphylococcus aureus , Cloruro de Polivinilo/química , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Staphylococcus aureus Resistente a Meticilina/efectos de la radiación , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/efectos de la radiación , Especies Reactivas de Oxígeno/metabolismo , Fármacos Fotosensibilizantes/farmacología , Fármacos Fotosensibilizantes/química
17.
J Hazard Mater ; 470: 134278, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38631247

RESUMEN

Resuspension caused by human walking activities is an important source of indoor bioaerosols and has been associated with health effects such as allergies and asthma. However, it is unknown whether inhalation of resuspended bioaerosols is an important exposure pathway for airborne infection. Also, crucial factors influencing the resuspension of settled microbes have not been quantified. In this study, we experimentally investigated the resuspension of culturable bacteria from human-stepping on polyvinyl chloride (PVC) flooring under different conditions. We determined the bacterial resuspension emission factor (ER), a normalized resuspension parameter for the ratio of resuspended mass in the air to the mass of settled particles, for two common bacteria, Escherichia coli and Salmonella enterica. The investigation involved varying factors such as microbial surface-attached durations (0, 1, 2, and 3 days), the absence or presence of nutrients on flooring surfaces, and changes in relative humidity (RH) (35%, 65%, and 85%). The results showed that, in the absence of nutrients, the highest ER values for E. coli and S. enterica were 3.8 × 10-5 ± 5.2 × 10-6 and 5.3 × 10-5 ± 6.0 × 10-6, respectively, associated with surface-attached duration of 0 days. As the surface-attached duration increased from 0 to 3 days, ER values decreased by 92% and 84% for E. coli and S. enterica, respectively. In addition, we observed that ER values decreased with the increasing RH, which is consistent with particle adhesion theory. This research offers valuable insights into microbial resuspension during human walking activities and holds the potential for assisting in the assessment and estimation of risks related to human exposure to bioaerosols.


Asunto(s)
Escherichia coli , Humedad , Caminata , Humanos , Pisos y Cubiertas de Piso , Salmonella enterica , Aerosoles , Contaminación del Aire Interior , Microbiología del Aire , Cloruro de Polivinilo/química , Nutrientes
18.
Int J Biol Macromol ; 266(Pt 1): 131190, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38552689

RESUMEN

In this study, new, functional hydroxyapatite-lignin hybrid systems were designed and characterized. The efficacy of the mechanical method utilized to obtain these systems was confirmed by Fourier transform infrared spectroscopy. The hybrid materials were also noted for their good electrokinetic stability and thermal stability. The introduction of 2.5 to 10 wt% hydroxyapatite-lignin systems into an unplasticized PVC blend using a two-step kneading and pressing method resulted in composites with relatively homogeneous distribution, as confirmed by SEM observations. The processing properties of the filler-containing blends were investigated using plastographometric analysis and MFR tests. The introduction of a lignin-predominant hybrid system into the PVC matrix results in a significant improvement of thermal stability, softening temperature, and tensile strength, while maintaining sufficient impact strength for numerous applications. Hybrid materials containing higher amounts of added lignin are promising materials with bacteriostatic properties. This can be utilized to stabilize and prevent the deposition of microorganisms, as well as the formation of biofilms, on material surfaces, thereby limiting the spread of pathogens. New eco-composites based on PVC and a hybrid filler containing lignin show promise in producing components with surfaces resistant to bacterial colonization. Hence, these materials could be used in medical and hospital equipment.


Asunto(s)
Durapatita , Lignina , Cloruro de Polivinilo , Lignina/química , Durapatita/química , Cloruro de Polivinilo/química , Resistencia a la Tracción , Temperatura , Espectroscopía Infrarroja por Transformada de Fourier
19.
Biodegradation ; 35(4): 451-468, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38289541

RESUMEN

Microplastics pose significant challenges to ecosystems and organisms. They can be ingested by marine and terrestrial species, leading to potential health risks and ecological disruptions. This study aims to address the urgent need for effective remediation strategies by focusing on the biodegradation of microplastics, specifically polyvinyl chloride (PVC) derivatives, using the bacterial strain Bacillus albus. The study provides a comprehensive background on the accumulation of noxious substances in the environment and the importance of harnessing biodegradation as an eco-friendly method for pollutant elimination. The specific objective is to investigate the enzymatic capabilities of Bacillus albus, particularly the alpha/beta hydrolases (ABH), in degrading microplastics. To achieve this, in-silico studies were conducted, including analysis of the ABH protein sequence and its interaction with potential inhibitors targeting PVC derivatives. Docking scores of - 7.2 kcal/mol were obtained to evaluate the efficacy of the interactions. The study demonstrates the promising bioremediation prospects of Bacillus albus for microplastics, highlighting its potential as a key player in addressing microplastic pollution. The findings underscore the urgent need for further experimental validation and practical implementation of Bacillus albus in environmental remediation strategies.


Asunto(s)
Bacillus , Biodegradación Ambiental , Cloruro de Polivinilo , Bacillus/enzimología , Bacillus/metabolismo , Cloruro de Polivinilo/química , Hidrolasas/metabolismo , Proteínas Bacterianas/metabolismo , Microplásticos/metabolismo , Simulación del Acoplamiento Molecular
20.
Dermatitis ; 35(2): 160-166, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-37669114

RESUMEN

Background: Polyvinyl chloride (PVC) gloves are recommended as a safe alternative for patients with rubber accelerator allergy. However, allergic contact dermatitis to other chemicals in PVC gloves has been reported. Objective: To analyze single-use PVC medical examination gloves in the United States for the presence of potential contact allergens. Methods: Using liquid chromatography-mass spectrometry, 20 unique PVC gloves were analyzed in triplicate for 6 chemicals: benzisothiazolinone, bisphenol A, mono(2-ethylhexyl) maleate, tricresyl phosphate, triphenyl phosphate, and triphenyl phosphite. Results: All 20 PVC gloves contained detectable quantities of benzisothiazolinone (range, 0.001-1.48 parts per million [ppm]), bisphenol A (0.01-0.11 ppm), triphenyl phosphate (0.01-2.11 ppm), and triphenyl phosphite (0.001-0.22 ppm). Eighteen (90%) gloves contained mono(2-ethylhexyl) maleate (0.001-0.14 ppm) and 3 (15%) contained tricresyl phosphate (0.001-0.002 ppm). Conclusions: Known allergens were present in all 20 PVC gloves. However, the detected levels were mostly low and their relationship with sensitization and elicitation thresholds requires further study.


Asunto(s)
Compuestos de Bencidrilo , Dermatitis Alérgica por Contacto , Organofosfatos , Fenoles , Fosfitos , Tiazoles , Tritolilfosfatos , Humanos , Estados Unidos , Alérgenos/efectos adversos , Cloruro de Polivinilo/efectos adversos , Cloruro de Polivinilo/química , Guantes Protectores , Pruebas del Parche , Dermatitis Alérgica por Contacto/diagnóstico , Dermatitis Alérgica por Contacto/etiología , Maleatos , Goma
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