Development of new antibacterial functionalised textiles and 3-D-printed filters for process water treatment

peer reviewe

Development of new antibacterial functionalised textiles and 3-D-printed filters for process water treatment

peer reviewe

Silane modified clay for enhanced dye pollution adsorption in water

peer reviewedA natural clay from Bakotcha in Cameroon was modified with two silanes, tetramethoxysilane (TMOS) and [3-(2-aminoethyl)aminopropyl]trimethoxysilane (EDAS) to increase its adsorption properties. The modified clay is intended to be used as an efficient adsorbent for organic pollutant removal from water. Three Clay/TMOS and two Clay/EDAS samples with different [silane]/[clay] ratios were produced and characterized by X-ray diffraction, N2 adsorption-desorption measurements, Inductively Coupled Plasma–Atomic Emission Spectroscopy and Scanning Electron Microscopy. Their adsorption properties were evaluated on three organic model pollutants (i.e. fluorescein, malachite green and brilliant violet diamond). A dilution of the montmorillonite structure of the raw clay is observed when it is modified with TMOS while its original crystalline structure is preserved with EDAS. The morphologies depended on the used silane: (i) with TMOS, highly porous materials with the formation of silica particles at the surface of the clay; (ii) with EDAS, a similar morphology as raw clay with EDAS grafted at the surface of the clay. Both morphologies give two different adsorption behaviors on the 3 pollutants. For the raw clay and the TMOS modified clays, similar adsorption properties are obtained with a better adsorption when the specific surface increases (when TMOS content increases). When clay is modified with EDAS, the adsorption properties change as the surface groups are different, these EDAS modified samples have less affinity with fluorescein and malachite green reducing the adsorption capacity for this kind of pollutants. The tuning of the raw clay with silane opens the way for the development of highly efficient adsorbent for pollutants in water from natural and inexpensive materials

Toward a European coastal observing network to provide better answers to science and to societal challenges : The JERICO research infrastructure

The coastal area is the most productive and dynamic environment of the world ocean, offering significant resources and services for mankind. As exemplified by the UN Sustainable Development Goals, it has a tremendous potential for innovation and growth in blue economy sectors. Due to the inherent complexity of the natural system, the answers to many scientific and societal questions are unknown, and the impacts of the cumulative stresses imposed by anthropogenic pressures (such as pollution) and climate change are difficult to assess and forecast. A major challenge for the scientific community making observations of the coastal marine environment is to integrate observations of Essential Ocean Variables for physical, biogeochemical, and biological processes on appropriate spatial and temporal scales, and in a sustained and scientifically based manner. Coastal observations are important for improving our understanding of the complex biotic and abiotic processes in many fields of research such as ecosystem science, habitat protection, and climate change impacts. They are also important for improving our understanding of the impacts of human activities such as fishing and aquaculture, and underpin risk monitoring and assessment. The observations enable us to better understand ecosystems and the societal consequences of overfishing, disease (particularly shellfish), loss of biodiversity, coastline withdrawal, and ocean acidification, amongst others. The European coastal observing infrastructure JERICO-RI, has gathered and organized key communities embracing new technologies and providing a future strategy, with recommendations on the way forward and on governance. Particularly, the JERICO community acknowledges that the main providers of coastal observations are: (1) research infrastructures, (2) national monitoring programs, and (3) monitoring activities performed by marine industries. The scope of this paper is to present some key elements of our coastal science strategy to build it on long term. It describes how the pan-European JERICO community is building an integrated and innovation-driven coastal research infrastructure for Europe. The RI embraces emerging technologies which will revolutionize the way the ocean is observed. Developments in biotechnology (molecular and optical sensors, omics-based biology) will soon provide direct and online access to chemical and biological variables including in situ quantification of harmful algae and contaminants. Using artificial intelligence (AI), Internet of Things will soon provide operational platforms and autonomous and remotely operated smart sensors. Embracing key technologies, high quality open access data, modeling and satellite observations, it will support sustainable blue growth, warning and forecasting coastal services and healthy marine ecosystem. JERICO-FP7 is the European 7th framework project named JERICO under Grant Agreement No. 262584. JERICO-NEXT is the European Horizon-2020 project under Grant Agreement No. 654410. JERICO-RI is the European coastal observing research infrastructure established and structured through JERICO-FP7 and JERICO-NEXT, and beyond

Development of new antibacterial functionalised textiles and 3-D-printed filters for process water treatment

Water is vital for life and the essential key to important industrial processes. Due to the increasing consumption and contamination, the access, treatment and safety of water is becoming challenging and costly. Therefore, new technologies have to be developed to ensure sustainable protection and safe access to water for both human consumption and industrial use. The DAF3D project aims to develop an innovative and sustainable 3-D-printed filter based on antibacterial functionalised textiles for water disinfection. The expected application is centred on production and reusability of process water from diverse industrial sectors and grey water within households. For instance, in the chemical and food industries, water recycling is enforced and cost-saving but biological safety is a major concern. Thus, the 3-D-printed filter composed of antibacterial functionalised textiles is a promising solution for these issues and can be implemented in a wide diversity of applications, configurations and dimensions. The innovative filter for disinfection will be composed of a thermoplastic for 3-D-printing in combination with textile materials pre-impregnated with antibacterial agents, such as zinc oxide (ZnO) structures doped with Cu and/or Al. These new antibacterial textiles are capable of generating in situ highly reactive oxidizing species, which can degrade a wide range of organic substances, including microorganisms. It has been shown that ZnO can be used for water hygienisation due to its antimicrobial capacity. Species generated by ZnO break through the cell wall, causing irreversible damage and leading to the cell death. Additive manufacturing technologies or 3-D-printing technologies are able to print filter materials with precisely defined structures. The innovative principle behind this manufacturing process enables the development of efficient flow paths through the filter and the possible inclusion of additives for expanding functionality and reactivity. However, several aspects must be considered when applying such materials to water disinfection, as the risk of degradation and leaching would cause severe problems. Therefore, this project aims to develop innovative materials to be used for water hygienisation without causing contamination. A material with these properties is not yet available on the market. Therefore, antibacterial textile micropowders based on ZnO will be incorporated into the thermoplastic compound at different concentrations, using a plastic extruder. Subsequently, a filament for 3-D-printing will be produced for supporting further manufacturing of the filter for process water disinfection. The developed antibacterial filter will be tested for the degradation of microorganisms, such as E. coli and others pathogens individually and/or in combination, in a variety of domestic and industrial process waters. Pre-treatments will be applied before the filter, depending on the process water to be treated. The tests will be performed in a bench scale demonstrator. The treated water will be accessed accordingly to evaluate disinfection efficiency and the reusability in the targeted industrial sector. In summary, the ultimate aim of the DAF3D project is to develop and validate a disinfection filter for reuse of process water. This is achieved by combining functionalised textiles impregnated with antimicrobial agents and a safe thermoplastic for 3-D-printed filters. The versatility of 3-D-printed antimicrobial filter will support SMEs on market creation. Moreover, the filter is a promising and competitive technology for replacing less-efficient and sustainable existing technology. Moreover, the flexibility will enable and/or increase the application of water recycling and reuse in industrial and private applications. The DAF3D project can have a significant impact on enabling sustainable treatment and safe access to water, which is a well-known resource but susceptible to contamination and source of critical health and environmental problems

L'arbre et la forêt dans les récits des jeux de société francophones

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Enhanced Decomposition of H2O2 Using Metallic Silver Nanoparticles under UV/Visible Light for the Removal of p-Nitrophenol from Water

peer reviewedThree Ag nanoparticle (NP) colloids are produced from borohydride reduction of silver nitrate in water by varying the amount of sodium citrate. These nanoparticles are used as photocatalysts with H2O2 to degrade a p-nitrophenol (PNP) solution. X-ray diffraction pa erns have shown the production of metallic silver nanoparticles, whatever the concentration of citrate. The transmission electron microscope images of these NPs highlighted the evolution from spherical NPs to hexagonal/rod-like NPs with broader distribution when the citrate amount increases. Aggregate size in solution has also shown the same tendency. Indeed, the citrate, which is both a capping and a reducing agent, modifies the resulting shape and size of the Ag NPs. When its concentration is low, the pH is higher, and it stabilizes the formation of uniform spherical Ag NPs. However, when its concentration increases, the pH decreases, and the Ag reduction is less controlled, leading to broader distribution and bigger rod-like Ag NPs. This results in the production of three different samples: one with more uniform spherical 20 nm Ag NPs, one intermediate with 30 nm Ag NPs with spherical and rod-like NPs, and one with 50 nm rod-like Ag NPs with broad distribution. These three Ag NPs mixed with H2O2 in water enhanced the degradation of PNP under UV/visible irradiation. Indeed, metallic Ag NPs produce localized surface plasmon resonance under illumination, which photogenerates electrons and holes able to accelerate the production of hydroxyl radicals when in contact with H2O2. The intermediate morphology sample presents the best activity, doubling the PNP degradation compared to the irradiated experiment with H2O2 alone. This be er result can be a ributed to the small size of the NPs (30 nm) but also to the presence of more defects in this intermediate structure that allows a longer lifetime of the photogenerated species. Recycling experiments on the best photocatalyst sample showed a constant activity of up to 40 h of illumination for a very low concentration of photocatalyst compared to the literature

Development of antibacterial functionalized textiles by 3D printing: development of zinc oxide catalysts

peer reviewe

Metallic Silver Nanoparticles as efficient photocatalysts to convert H2O2 in hydroxyl radicals for organic pollutant degradation in water

peer reviewedAg nanoparticle (NP) colloids are produced from borohydride reduction of silver nitrate in water by varying the amount of sodium citrate. These nanoparticles are used as photocatalysts with H2O2 to degrade a p-nitrophenol (PNP) solution. X-ray diffraction patterns have shown the production of metallic silver nanoparticles, whatever the concentration of citrate. The transmission electron microscope images of these NPs highlighted the evolution from spherical NPs to hexagonal/rod-like NPs with broader distribution when the citrate amount increases. Aggregate size in solution has also shown the same tendency. Indeed, the citrate, which is both a capping and a reducing agent, modifies the resulting shape and size of the Ag NPs. When its concentration is low, the pH is higher, and it stabilizes the formation of uniform spherical Ag NPs. However, when its concentration increases, the pH decreases, and the Ag reduction is less controlled, leading to broader distribution and bigger rod-like Ag NPs. This results in the production of three different samples: one with more uniform spherical 20 nm Ag NPs, one intermediate with 30 nm Ag NPs with spherical and rod-like NPs, and one with 50 nm rod-like Ag NPs with broad distribution. These three Ag NPs mixed with H2O2 in water enhanced the degradation of PNP under UV/visible irradiation. Indeed, metallic Ag NPs produce localized surface plasmon resonance under illumination, which photogenerates electrons and holes able to accelerate the pro-duction of hydroxyl radicals when in contact with H2O2. The intermediate morphology sample presents the best activity, doubling the PNP degradation compared to the irradiated experiment with H2O2 alone. This better result can be attributed to the small size of the NPs (30 nm) but also to the presence of more defects in this intermediate structure that allows a longer lifetime of the photogenerated species. Recycling experiments on the best photocatalyst sample showed a constant activity of up to 40 h of illumination for a very low concentration of photocatalyst compared to the literature