Cork processing wastewater treatment/valorisation by nanofiltration

Nanofiltration process for the treatment/valorisation of cork processing wastewaters was studied. A DS-5 DK 20/40 (GE Water Technologies) nanofiltration membrane/module was used, having 2.09 m(2) of surface area. Hydraulic permeability was determined with pure water and the result was 5.2 L.h(-1).m(-2).bar(-1). The membrane presents a rejection of 51% and 99% for NaCl and MgSO4 salts, respectively. Two different types of regimes were used in the wastewaters filtration process, total recycling mode and concentration mode. The first filtration regime showed that the most favourable working transmembrane pressure was 7 bar working at 25 degrees C. For the concentration mode experiments it was observed a 30% decline of the permeate fluxes when a volumetric concentration factor of 5 was reached. The permeate COD, BOD5, colour and TOC rejection values remained well above the 90% value, which allows, therefore, the concentration of organic matter (namely the tannin fraction) in the concentrate stream that can be further used by other industries. The permeate characterization showed that it cannot be directly discharged to the environment as it does not fulfil the values of the Portuguese discharge legislation. However, the permeate stream can be recycled to the process (boiling tanks) as it presents no colour and low TOC (< 60 ppm) or if wastewater discharge is envisaged we have observed that the permeate biodegradability is higher than 0.5, which renders conventional wastewater treatments feasible.

A execução das normas ambientais comunitárias na UE

Este últimos anos aumentaram as dificuldades quer relativamente à execução correcta e em tempo da legislação comunitária do ambiente, quer na prática, a sua aplicação adequada. Esta situação reflecte-se no número de queixas que a Comissão recebeu em cada ano e número de processos de infracção por ela intentados. Tal como nos anos precedentes o sector do Ambiente representou no último ano mais de 1/3 dos casos de infracção analisados pela Comissão. A Comissão recorreu ao Tribunal de Justiça intentando 65 processos contra os Estados Membros e enviou 137 pareceres fundamentados nos termos do art.226 do Tratado. O número de novas queixas, as quais se referem sobretudo à “má aplicação” presumida do direito comunitário do ambiente é muito elevado, desde 1996, data em que a Comissão publicou a sua comunicação intitulada “Execução do Direito Comunitário do Ambiente”. Só em 2002 registaram-se 555 novas queixas por violação do direito comunitário do ambiente. Um número considerável das queixas em questão deram também origem a questões escritas e petições ao Parlamento Europeu. O processo previsto no art. 228 que pode levar a sanções pecuniárias revelou-se eficaz em última instância para obrigar os Estados Membros a tomar as medidas necessária à execução dos Acórdãos do Tribunal de Justiça. Em 2002 a Comissão por exemplo dirigiu aos Estados Membros 17 notificações de incumprimento, pareceres fundamentados nos termos do art. 228. O objectivo é sempre melhorar a aplicação do direito comunitário do ambiente e é evidente que as queixas e o Tribunal não são suficientes pra tal. Tem de existir uma maior colaboração entre os Estados Membros e a Comissão durante as etapas do ciclo de execução, a elaboração de novos métodos de trabalho e a implementação duma consciência cívica ambiental. E isto é especialmente importante na perspectiva do alargamento, se se pretender como pretende, que os novos Estados Membros transponham e executem correctamente a “Legislação Comunitária” nos prazos acordados.

Fungal contamination assessment in Portuguese elderly care centers

Individuals spend 80-90% of their day indoors and elderly subjects are likely to spend even a greater amount of time indoors. Thus, indoor air pollutants such as bioaerosols may exert a significant impact on this age group. The aim of this study was to characterize fungal contamination within Portuguese elderly care centers. Fungi were measured using conventional as well as molecular methods in bedrooms, living rooms, canteens, storage areas, and outdoors. Bioaerosols were evaluated before and after the microenvironments' occupancy in order to understand the role played by occupancy in fungal contamination. Fungal load results varied from 32 colony-forming units CFU m(-3) in bedrooms to 228 CFU m(-3) in storage areas. Penicillium sp. was the most frequently isolated (38.1%), followed by Aspergillus sp. (16.3%) and Chrysonilia sp. (4.2%). With respect to Aspergillus genus, three different fungal species in indoor air were detected, with A. candidus (62.5%) the most prevalent. On surfaces, 40 different fungal species were isolated and the most frequent was Penicillium sp. (22.2%), followed by Aspergillus sp. (17.3%). Real-time polymerase chain reaction did not detect the presence of A. fumigatus complex. Species from Penicillium and Aspergillus genera were the most abundant in air and surfaces. The species A. fumigatus was present in 12.5% of all indoor microenvironments assessed. The living room was the indoor microenvironment with lowest fungal concentration and the storage area was highest.

Strabismus, visual acuity, and uncorrected refractive error in Portuguese children aged 6 to 11 years

Introduction: Visual anomalies that affect school-age children represent an important public health problem. Data on the prevalence are lacking in Portugal but is needed for planning vision services. This study was conducted to determine the prevalence of strabismus, decreased visual acuity, and uncorrected refractive error in Portuguese children aged 6 to 11 years. Methods and materials: A cross-sectional study was carried out on a sample of 672 school-age children (7.69 ± 1.19 years). Children received an orthoptic assessment (visual acuity, ocular alignment, and ocular movements) and non-cycloplegic autorefraction. Results: After orthoptic assessment, 13.8% of children were considered abnormal (n = 93). Manifest strabismus was found in 4% of the children. Rates of esotropia (2.1%) were slightly higher than exotropia (1.8%). Strabismus rates were not statistically significant different per sex (p = 0.681) and grade (p = 0.228). Decreased visual acuity at distance was present in 11.3% of children. Visual acuity ≤20/66 (0.5 logMAR) was found in 1.3% of the children. We also found that 10.3% of children had an uncorrected refractive error. Conclusions: Strabismus affects a small proportion of the Portuguese school-age children. Decreased visual acuity and uncorrected refractive error affected a significant proportion of school-age children. New policies need to be developed to address this public health problem.

Viability of the use of thin-film A-SiC:H photodiodes for protein identification

In this paper, we present a multilayer device based on a-Si:H/a-SiC:H that operates as photodetector and optical filter. The use of such device in protein detection applications is relevant in Fluorescence Resonance Energy Transfer (FRET) measurements. This method demands the detection of fluorescent signals located at specific wavelengths bands in the visible part of the electromagnetic spectrum. The device operates in the visible range with a selective sensitivity dependent on electrical and optical bias. Several nanosensors were tested with a commercial spectrophotometer to assess the performance of FRET signals using glucose solutions of different concentrations. The proposed device was used to demonstrate the possibility of FRET signals detection, using visible signals of similar wavelength and intensity. The device sensitivity was tuned to enhance the wavelength band of interest using steady state optical bias at 400 nm. Results show the ability of the device to detect signals in this range. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Reactores a tório: o futuro da energia nuclear de fissão

Dissertação para a obtenção do grau de mestre em Engenharia Electrotécnica Ramo de Energia