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The main objective of this study was to assess the environmental risk of chars derived from the pyrolysis of mixtures of pine, plastics, and scrap tires, by studying their leaching potential and ecotoxicity. Relationships between chemical composition and ecotoxicity were established to identify contaminants responsible for toxicity. Since metallic contaminants were the focus of the present study, an EDTA washing step was applied to the chars to selectively remove metals that can be responsible for the observed toxicity. The results indicated that the introduction of biomass to the pyrolysis feedstock enhanced the acidity of chars and promote the mobilisation of inorganic compounds. Chars resulting from the pyrolysis of blends of pine and plastics did not produce ecotoxic eluates. A relationship between zinc concentrations in eluates and their ecotoxicity was found for chars obtained from mixtures with tires. A significant reduction in ecotoxicity was found when the chars were treated with EDTA, which was due to a significant reduction in zinc in chars after EDTA washing.

Carbonaceous solid products resulting from thermochemical processes (pyrolysis, gasification), commonly known as chars, are emerging as low-cost sorbents of metallic contaminants, being their effectiveness already demonstrated in several studies (Inyang et al., 2012; Fuente-Cuesta et al., 2012; Ko³odyñska et al., 2012; Quek and Balasubramanian, 2009; Devecia and Kar, 2013). Given the fact that the commercial viability of pyrolysis and gasification plants for the treatment and valorisation of waste streams are increasingly being demonstrated, it is expected that large amounts of solid chars will be available in a near future, as by-products or as main products (pyrolysis-carbonization). Chars may possess several characteristics which turn them effective as heavy metals sorbents: aromatic carbon matrix with relatively porous structures, the presence of functional groups or inorganic inclusions in the surface providing active sites to interact with metallic species (Inyang et al., 2012; Fuente-Cuesta et al., 2012; Ko³odyñska et al., 2012; Quek and Balasubramanian, 2009; Devecia and Kar, 2013; Lu et al., 2012). Lead (Pb2+) is considered as a priority substance in the field of European water policy (EU, 2000; EU, 2008) which means that measures shall be taken by the Member States to eliminate or reduce the water pollution caused by this pollutant in order to fulfill the emission/discharge limits legislated for this compound.

The minor components of honey (mineral components, flavonoids, amino acids, volatile compounds, etc.) are mainly responsible for the individuality of each kind of honey and the character of this nutraceutical food product. The quality parameters are described in Directive 2001/110/EC of 21 December 2001 and are accepted in Europe as the minimum quality criteria that must be respected. However, the value of honey as a functional food product is also supported by its biological activity that depends on its microcomponents. The botanical and regional specificity could be demonstrated through the awarding of Appellations of Origin (PDO), aiming to highlight the quality of particular types of honey and increase their commercial value. This is a growing trend in European countries supported by a characterization of quality parameters such as HMF content, diastase activity, antioxidant activity, or mineral composition.

O própolis é um produto escuro e pegajoso, fabricado pelas abelhas a partir de materiais vegetais resinosos e a partir de fluido segregado pelas próprias abelhas. As propriedades antioxidantes, antimicrobianas e antimutagénicas do própolis são frequentemente referidas na chamada medicina popular, mas a sua capacidade de reforço do sistema imunitário é talvez a propriedade mais explorada comercialmente em formulações como extractos hidroalcoólicos ou xaropes. As aplicações tópicas têm também sido uma área de utilização preferencial deste produto.

Yogurt is a functional food mainly known by its prebiotic and probiotic properties. On the other hand, the addition of fruit rich jams or honey to yogurts has been widely used to improve the organoleptic and nutritional value of this food product. These components also allow obtaining a different range of products that can gain the consumer preference. Fruits and honey are themselves functional products rich in nutraceutical components such as vitamins or flavonoids. The antioxidant activity of different foods has been associated with the presence of such nutraceutical compounds therefore their presence in yogurt formulations should have a similar impact in their antioxidant power.

Fluidos biológicos como plasma ou urina reflectem o estado metabólico do indivíduo num dado momento. Este estado metabólico é fortemente influenciado tanto por factores genéticos como pelo estilo de vida. O “stress” oxidativo pode aumentar como resultado de uma dieta pobre ou de hábitos desadequados como o tabagismo, que aumentam a exposição a espécies reactivas de oxigénio. A adopção de uma dieta rica em compostos bioactivos com actividade anti-radicalar pode contribuir para reduzir o stress oxidativo na população em geral e particularmente em mães durante a fase de amamentação.

Breast milk is generally considered the best nutrition option for children of less than one year of age. In the first months of life, breast feeding is the source of essential nutrients but also of immunitary defense factors that cannot be found in formula-milk. The nutrition of the mother plays a fundamental role in its state of health and consequently in the quality of its breast milk. The determination of the antioxidant activity of breast milk allows a global characterization of its value not only as a nutrient but also as a functional food with relevance in the minimization of the oxidative stress of the newborn. These studies can contribute to the definition of appropriate diets for the breast-feeding period and for the selection of appropriate milks to be used with premature infants.

The present work is devoted to the study chars obtained in the co-pyrolisis of plastics, biomass and tyres wastes. The composition of these chars is not yet well studied and only recent an attempt was made by the aithors to provide some information about the composition and risk assessment of these materials. The objectives of this work were to perform solvent extractions, using differents, in chars obtained in the co-pyrolysis process to evaluate the extraction efficiency by characterising the different solvent extracts obtained as well as the extracted chars, to perform a chemical ans bioassay franctionation in the most toxic crude extraction in order to study the chemical composition of the fractions as well as their individual contribution to the global toxicity of the crude extarct. The results will allow to conclude which solvent should be used in the decontamination of the pyrolysis chars.

Rapeseed oil was rapeseed oil hydrogenated using a hydrogen pressure of 160psi, over a temperature range from 200ºC to 400ºC. Residence time was varied from 6 to 120 min. The reaction was performed in the absence and in the presence of specific inorganic catalyst. The gaseous liquid and solid yield were determined. The liquid phase was characterized using elemental analysis FT-IR, GC-HD (boiling point profile) and GC-MS (chemical families profile). At a temperature of 400ºC and a residence time of 120 min the yield of hydrocarbon products is 90% in the presence of catalyst and 83% in the absence of the catalyst.

The main objective of this study is to identify the experimental conditions that favor the production of bi-oil from pyrolisis of polypropylene (PP) coming from the scrapping of end-of-life vehicles. The experimental conditions tested were: initial pressure (2.1 to 10.3 bar), temperature (350 to 430ºC) and reaction time (1 to 900 s). The study reveals that the conditions that increase the rate of conversation of PP into liquid fraction (>80%) correspond to an initia pressure of 50 psi (3,45 bar), a temperature of 400ºC and a reaction time 15 minutes. All products obtained, gases, liquids and solids, were characterized and analysed by gas chromatography (GC) and mass spectrometry (GC-MS).

The high amounts of solid waste produced in industrial installations and in urban centers is a complex problem of today's society. The traditional strategies for solid waste transformation and disposal include and filling or incineration. Other approaches are being exploited namely waste selective collection and recycling on the energetic valorization of solid wastes through pyrolysis. In the pyrolytic process, the wastes are converted into a gaseous and liquid phase that can be used in energy production or as feedstock in chemistry industries. A solid residue (char) is also produced in a proportion that depends on the pyrolysis conditions. Even when the operating condiions are optimized in order to minimize the solid fraction, a resonable amount of chars are obtained. Those chars are mainly composed of a carbon-rich matrix that contains the mineral matter initially present in the wastes as well as components of the liquid fraction. Therefore, these solid residues have a toxicity potential due to the presence of heavy metals or organic compounds that must be assessed in order to define their safe reutilization or disposal. In the present study, the chars produced in the co-pyrolysis of plastics, pine biomass and tyres were characterized through chemical and ecotoxicological tests. A fraction of the solid chars was treated by extraction with dichloromethane. Different volatibility groups of compounds present in the extracted and non extracted char were evaluated. A selected group of heavy metals was determined in both chars. Chars were subjected to the leaching test ISO/TS 21268-2 and the resulting eluates were further characterized by determining a group of inorganic and organic parameters. An ecotoxicological characterization was performed by using he bio-indicator Vibrio fischeri. The chemical and ecotoxicological results were compared and analysed according to the council Decision 2003/33/CE and the Criteria on the Evaluation Methods of Waste Ecotoxicity (CEMWE). The results of the chemical characterization indicate that the extraction of the char residues with an appropriate organic solvent allows the sufficient elimination of the volatile organic contaminants thus decreasing the potential toxicity of these chars. The semi-volatile and non-volatile fractions were not, apparently, affected by this pre-treatment. Regarding the release of heavy metals from extracted and non-extracted chars during the leaching tests, a strong contamination with Zn was found in both eluates, which contribute to a classification of the corresponding chars as hazardous and ecotoxic materials. Also the results of the ecotoxicological characterization of the eluates led to a classification of these chars as ecotoxic materials.

The replacement of fossil fuels by renewable fuels can contribute to improve the environmental performance of the power production and to move forward in the sustainability way. The experience has shown that the availability of alternative fuels can be an obstacle for its extensive use for energy production, since biomass is not always available. The use of non-hazardous wastes may be a good alternative to biomass, mainly if they are economically unattractive for recycling or if they present a high cost for land-filling. The co-firing of non-hazardous wastes with coal is, therefore, a subject of great interest for the sustainability of energy production and the reduction of the emissions of fossil greenhouse gases. The use of these wastes for energy is promising if they combine well with other fuels during the conversion process for energy production and have no negative effect on the combustion system, on the ash quality and on the gaseous emissions.

Revista Lusófona de Humanidades e Tecnologias