Designing nanocomposites using supercritical CO2 to insert Ni nanoparticles into the pores of nanopatterned BaTiO3 thin films

A new concept to prepare nanocomposite thin films is explored. Two chemical-based bottom-up steps are used to design functional films including: i) block copolymerassisted self-assembly of a porous matrix; and ii) impregnation of nanoparticles from a ferroic phase within the pores by supercritical CO2 deposition. Porous nanopatterned BaTiO3 thin films with ca. 17 nm of thickness are prepared using a cost-effective solgel solution containing a block copolymer and evaporation-induced self-assembly methodology. Hexagonal-arranged pores with diameter of ca. 95 nm, running perpendicularly to the substrate are filled with Ni nanoparticles using the supercritical fluid deposition technique from reduction of hydrated nickel nitrate in a supercritical CO2-ethanol mixture at 250 ºC. Small Ni nanoparticles with 21 ± 5 nm nm are selectively deposited inside the pores of the porous matrix. Structural and magnetic properties prove the coexistence of both phases

Biological treatment of a contaminated gaseous emission from a paint and varnish plant—from laboratory studies to pilot-scale operation

A Vapour-Phase Bioreactor (VPB), namely a biotrickling filter, was scaled-up and operated in-situ for the treatment of gaseous emissions from a paint and varnish industrial plant. A microbial culture able to degrade the target compounds was enriched and a laboratory-scale VPB was established in order to evaluate the treatment's performance. The VPB presented removal efficiencies higher than 90% when exposed to Organic Loads (OL) of ca 50 g h−1 m−3 of reactor. The VPB was exposed to dynamic conditions often found in-situ (eg night and weekend shutdown periods) and showed a fast capacity to recover, with and without mineral medium recirculation. After a prolonged interruption period (10 months), the VPB was not able to cope with OL of ca 25 g h−1 m−3 of reactor and re-inoculation was required in order to recover the treatment performance. The VPB also showed limited treatment when exposed to higher OL (ca 500 g h−1 m−3 of reactor). The VPB was then scaled-up and a 3 m3 VPB was operated in-situ, showing removal efficiencies higher than 50% when exposed to an OL of c 5 g h−1 m−3 of reactor, thus complying with current legal demands. The addition of a maintenance feed was shown to be a useful tool for VPB pilot-scale operation when shutdown periods occurred. A factorial design of experiments was carried out, which allowed reduction to one-tenth of the initial supply of the main mineral medium constituents, namely phosphate buffer, ammonium and magnesium salts, and also elimination of the metal supplement. Overall, the VPBs were shown to be robust equipment, being able to respond actively to dynamic treatment scenarios, particularly night and weekend shutdown periods. Copyright © 2003 Society of Chemical Industr

Faecal indicator bacteria and listeria monocytogenes in ponds, natural and constructed wetlands: Evaluating water quality

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Occurrence of fecal bacteria and zoonotic pathogens in different water bodies: supporting water quality management

Water contaminated with microbiological and chemical constituents can cause a variety of diseases. Water bodies may become contaminated by wild and domestic animal feces, agricultural runoff or sewage, and are often overlooked as a reservoir and source of human infection by pathogenic microorganisms. The objectives of this study were to evaluate the presence of the zoonotic pathogens, Salmonella spp. and Listeria monocytogenes, in various water bodies located in urban and rural areas in the north of Portugal. Water samples were collected from six sites, including natural and artificial ponds, in two different time periods. Several water quality physicochemical parameters, as well as fecal indicator bacteria, were evaluated. High levels of total coliforms (>1.78 log CFU/100 mL) were detected in all samples, and substantial numbers of Enterococcus (>2.32 log CFU/100 mL) were detected in two ponds located in a city park and in an urban garden. Escherichia coli counts ranged from undetectable to 2.76 log CFU/100 mL. Salmonella spp. was isolated from two sites, the city park and the natural pond, while L. monocytogenes was isolated from three sites: the city garden, the natural pond and the artificial pond, both in the rural area. These data show that artificial and natural ponds are a reservoir of fecal indicator bacteria and enteric and zoonotic pathogens. This may impact the potential risks of human infections by potential contaminants during recreational activities, being important for assessing the water quality for strategic management of these areas.info:eu-repo/semantics/publishedVersio

Approach to phytotechnology regulatory and market trends in Europe: future perspectives

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Valorisation of mining areas using phytotechnologies - a field experiment

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Utilisation of pulp and paper industry wastes as raw materials in cement clinker production

The present work assesses the incorporation of grits and dregs, both wastes from cellulose and paper making industry, in cement clinker production. Industrial trials were developed with conventional raw clinker, used as a reference material and with the addition of grits and dregs, 0.25% and 0.13%, respectively. All raw meals were fired at 1400?1500°C. Chemical composition of the final mixtures, gaseous emissions quality during clinker production and leaching behaviour of the final products were evaluated. The results show that such incorporation could be an effective process for waste management from both the environmental and economic points of view.(undefined

Non-thermal synergistic approach to Listeria monocytogenes inactivation in milk: the combined effect of high pressure and bacteriophage P100

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High hydrostatic pressure and pediocin PA-1 as a synergistic system to listeria monocytogenes inactivation in fermented meat sausage

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Biodegradation of 2-fluorobenzoate in upflow fixed bed bioreactors operated with different growth support materials

Three upflow fixed bed bioreactors treating an aqueous stream containing 2-fluorobenzoate were operated for a period of 7months, during which they were exposed to high organic loading rates and starvation. The reactors contained granular activated carbon (GAC), polyethylene (PE) particles and expanded clay (EC) respectively as growth support for microbial biofilms. The performance of the reactors was compared and the biofilm microbial population was followed by cell counting and denaturing gradient gel electrophoresis (DGGE). The reactor containing GAC always had 100% removal efficiency owing to the adsorption properties of thematerial combined with biodegradation. The GAC reactor also recovered better after starvation periods in the sense that it showed more stable behaviour than the reactors containing EC and PE. The highest biological elimination capacity was observed for the reactor containing EC, which reached 200mg day−1 L−1 during reactor start-up, but during long-termoperation the reactor containing GAC showed the highest biological elimination capacity, 140mg day−1 L−1. DGGE analysis indicated that starvation periods seemed to be responsible for shifts in the microbial population