14 research outputs found
Mitigation of membrane particulate fouling by nano/microplastics via physical cleaning strategies
No full textMitigation of membrane particulate fouling by nano/microplastics via physical cleaning strategie
Membrane fouling by nanofibres and organic contaminants – Mechanisms and mitigation via periodic cleaning strategies
No full textMembrane fouling by nanofibres and organic contaminants – Mechanisms and mitigation via periodic cleaning strategie
Kinetic and mechanistic aspects of ultrafiltration membrane fouling by nano- and microplastics
No full textThe mechanical and chemical breakdown of plastic litter increases the release of nano- and microplastics, which have the potential to impact the performance of membranes processes used in water treatment plants. In this work, the extent of fouling of a commercial ultrafiltration poly(sulfone) membrane induced by nano- and microplastics ranging from 13 to 690 nm in size was investigated. The cross-flow filtration of the plastic particles over 48 h at a 1 bar pressure reduced the permeate water flux by 38% compared to pure water filtration. Over 25% of the nano- and microplastics initially present in the feed were absorbed onto the membrane surface within the 48 h of filtration. Particulate fouling mechanism was sequentially modelled into intermediate and complete pore blockage, followed by cake layer formation. Hydrophobic interactions and surface repulsion forces were found to dictate the adsorption rate of the nano- and microplastics onto the membrane surface. This work opens the understanding of NPs/MPs interactions with water filtration processes and demonstrates the need to develop solutions limiting the impact of NPs/MPs on current treating units
Mitigation of membrane fouling by nano/microplastics via surface chemistry control
No full textMitigation of membrane fouling by nano/microplastics via surface chemistry contro
Toxicity of nanofibers on zebrafish embryogenesis – Impact of materials properties on inflammatory responses
No full textTextile microfibers are the most common form of microplastic pollution and among the most dangerous to wildlife across multiple biomes. Besides toxicological challenges arising from their shapes, the morphology of fibrous materials make them excellent adsorbents and transportation media for harmful chemical pollutants and support both uptake and bioaccumulation across living organisms. The fragmentation of microfibers used in the textile industry is shown to lead to the formation of a broad range of sub-micron and nanofibers, with greater surface to volume ratio and much finer diameters, whose toxicity and environmental impact are not yet understood. Here, the impact of nanofibers on zebrafish embryos is studied to reveal risks associated with nanofiber pollution during early developmental stages. Exposure of embryos to nanofibers at a similar concentration to what has been observed in polluted water streams was found to dramatically increase apoptosis, neutrophils, and cytokine production that the chorion was unable to protect against. Furthermore, disturbed vascular basement membrane assembly in exposed embryos was detected leading to an expanded dorsal aorta diameter. These results obtained with model nanofibers demonstrate the risks of fragmented microplastics and the impact of surface properties on uptake and response by living organisms
Toxicity of nanofibers on zebrafish embryogenesis – Impact of materials properties on inflammatory responses
No full textToxicity of nanofibers on zebrafish embryogenesis – Impact of materials properties on inflammatory response
Release of hazardous nanoplastic contaminants due to microplastics fragmentation under shear stress forces
No full textRelease of hazardous nanoplastic contaminants due to microplastics fragmentation under shear stress force
Nano/micro plastics – Challenges on quantification and remediation: A review
No full textNano/micro plastics – Challenges on quantification and remediation: A revie
Development of a functional prototype for laboratory scale filtration of microplastics using the bioinspired rebound separation mechanism
Get PDFAl día de hoy no existe una normativa nacional que especifique las concentraciones de microplásticos permisibles en los vertimientos de aguas, por lo que muchos procesos dentro de la industria o sistemas de tratamiento de aguas residuales no cuentan con mecanismos específicos para la filtración y separación de los mismos, generando así, grandes problemas medioambientales y de salud. Como propuesta de solución, en este trabajo de grado se presenta el desarrollo de un prototipo funcional de filtración de microplásticos a escala de laboratorio, implementando el mecanismo bioinspirado conocido como separación por rebote presente en las mantarrayas, con un porcentaje de remoción del 89.73% para partículas con un tamaño superior a los 100 μm y velocidades de trabajo máximas de 0,7 m/s. Se evaluó su funcionamiento y eficiencia de filtración de forma computacional y real teniendo en cuenta sus variables críticas de velocidad de flujo, carga de microplásticos y tamaño de partícula. De esta manera, este proyecto presenta un nuevo mecanismo para eliminar rápidamente los microplásticos con una alta eficiencia y aplicabilidad en usos industriales, que es prometedora para remediar este tipo de contaminación del agua.BioingenieroPregradoToday there is no national regulation that specifies the concentrations of microplastics permissible in water discharges, so many processes within the industry or wastewater treatment systems do not have specific mechanisms for filtration and separation of them, thus generating major environmental and health problems. As a proposed solution, this degree work presents the development of a functional prototype for microplastic filtration at laboratory scale, implementing the bio-inspired mechanism known as rebound separation present in manta rays, with a removal percentage of 88.8% for particles larger than 100 μm and maximum working speeds of 0.7 m/s. Its performance and filtration efficiency were evaluated computationally and real, taking into account its critical variables of flow velocity, microplastic load and particle size. Thus, this project presents a new mechanism to rapidly remove microplastics with high efficiency and applicability in industrial uses, which is promising for remediating this type of water pollution
Evaluación de las propiedades mecánicas de mezclas asfálticas modificadas con PET
No full textLa elevada producción de residuos plásticos y la falta de metodologías amigables para su valorización se convierte en un problema medio ambiental que requiere estrategias inmediatas. La incorporación de residuos plásticos en mezclas asfálticas se perfila como una estrategia ambientalmente amigable para su aprovechamiento. Este trabajo presenta las propiedades mecánicas de mezclas asfálticas tipo MDC-19 (mezcla densa en caliente de 19mm) con reemplazos en volumen del 5%, 7.5% y 10% del asfalto por residuos PET utilizando un método de incorporación húmeda. Se evaluó la estabilidad, el flujo, los vacíos con aire y la susceptibilidad a la humedad. Los resultados indicaron que, a medida que se aumenta el contenido de PET, se producen disminuciones en la estabilidad Marshall y la susceptibilidad a la humedad, así como un aumento en los vacíos con aire y el flujo. En particular, la mezcla asfáltica modificada con un 5% de PET en el volumen de asfalto mostró una estabilidad de 1438 kgf y una susceptibilidad a la humedad del 76.4%, equivalente al 97% y al 93% respectivamente de la mezcla asfáltica tradicional. Estos resultados muestran el potencial que tiene la sustitución del asfalto por residuos plásticos proporcionando una estrategia para la valorización de los residuos plásticos en beneficio del medio ambiente.The high production of plastic waste and the lack of friendly methodologies for its recovery becomes an environmental problem that requires immediate strategies. The incorporation of plastic waste in asphalt mixtures is outlined as an environmentally friendly strategy for its use. This work presents the mechanical properties of MDC-19 type asphalt mixtures (19mm hot dense mixture) with volume replacements of 5%, 7.5% and 10% of asphalt by PET residues using a wet incorporation method. Stability, flow, air voids and susceptibility to moisture were evaluated. The results indicated that as the PET content increases, decreases in Marshall stability and susceptibility to moisture occur, as well as an increase in air voids and flow. In particular, the modified asphalt mixture with 5% PET in the asphalt volume showed a stability of 1438 kgf and a susceptibility to moisture of 76.4%, equivalent to 97% and 93% respectively of the traditional asphalt mixture. These results show the potential of replacing asphalt with plastic waste by providing a strategy for the recovery of plastic waste for the benefit of the [email protected]@[email protected]
