Browsing by Issue Date, starting with "2021-02"
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- Comparison of soil contamination at the selected European copper minesPublication . Andráš, Peter; Midula, Pavol; Matos, João Xavier; Buccheri, Giuseppe; Drimal, Marek; Dirner, Vojtech; Melichová, Zuzana; Turisová, IngridABSTRACT: This article reports the results of a study concerning contamination of the dump-fields by potentially toxic elements at five abandoned copper mines: Ľubietová, Špania Dolina (Slovakia), Libiola, Caporciano (Italy) and São Domingos (Portugal). This paper offers an updated description of soil contamination at the individual deposits and indicates a possible solution of the derived environmental problems. Contamination of technosoils by PTEs at the dump-fields shows an irregular spatial distribution of Fe, Cr, Mn, Co, Ni, Cu, Zn, As, Cd, Sb and Pb. Contents of PTEs often exceed both national and EU law limits. Whereas at Ľubietová, Špania Dolina and Caporciano the environmental risk is limited, at Libiola and São Domingos it seems to be very heavy. The technosoil (slag) of the dump-fields is not well aerated and the soil colloids have (except for Špania Dolina) negative surface charge, so they are suitable for PTEs sorption. The main environmental risk in the mining area of Sao Domingos district is the long time formation of acid mine drainage water and the high Zn, As and Pb contents. The release of PTEs to the environmental components may be limited by phytostabilization and immobilization of metals, by suitable admixtures into the technosoil/slag. The environmental situation at Caporciano is not so compromised as at São Domingos mining area. Phytostabilization will be able to stop erosion, and installation of wetlands under the dump will stop the release of Cu to the environment.
- On the relation of geology, natural ventilation and indoor radon concentration: the northern Portugal case studyPublication . Curado, António; I. Lopes, Sérgio; Antão, Ana Maria Morais CaldasAlto Minho region, Northwest of Portugal, presents high indoor radon concentrations due to the granitic nature of the soil. Indoor radon concentration is related to the amount of uranium and radium in the building foundation soil. According to the World Health Organization, it is proved that radon exposure in poorly ventilated buildings enhances lung cancer risk. An assessment campaign in a set of granitic buildings in the Alto Minho region, based on short-term measurements, was carried out with a specific focus on the influence of occupancy and ventilation actions performed by residents on the variation of radon concentration, indoor air temperature, and relative humidity. Results attained show to exist an influence of the air renovation on the reduction of radon concentration, therefore, buildings with low occupancy and reduced ventilation present higher indoor radon concentration and poor thermal comfort conditions. 67% of the evaluated buildings show radon concentrations below the reference value of 300 Bq.m−3 suggested by Portuguese regulation, highlighting the importance of human occupancy – mostly through passive ventilation processes – as a radon concentration mitigation factor. On the other hand, buildings sporadically occupied and, therefore, badly ventilated show higher indoor radon concentrations. Likewise, building where occupants reveal to have a lack of ventilation routine, present also high indoor radon concentrations.
- Evaluating low-cost substrates for Crypthecodinium cohnii lipids and DHA production, by flow cytometryPublication . Taborda, Tiago; Moniz, Patricia; Reis, Alberto; Silva, Teresa Lopes daABSTRACT: Crypthecodinium cohnii growth was studied on pure carbon sources (glucose, acetate, glycerol) and low-cost complex carbon sources (sugarcane molasses, crude glycerol and vinegar effluent) for lipid and DHA production. Among the pure substrates, glucose induced the highest lipid content (14.75% w/w DCW) and DHA content (7.14 mg g(-1) DCW). Among the low-cost substrates, the highest lipid and DHA content were observed for the crude glycerol assay (14.7% w/w DCW and 6.56 mg g(-1), respectively). Molasses induced the highest proportion of DHA of total fatty acids (49.58% w/w TFA) among all the substrates studied. Flow cytometric analysis revealed that the vinegar effluent induced the highest proportion of C. cohnii cells with injured membrane (92.8%). These results foresee the possibility of using these low-cost substrates at a larger scale for C. cohnii DHA and biodiesel production, aiming at zero wastes and process costs reduction.
- Market design for a reliable ~100% renewable electricity system: Deliverable D3.5Publication . Morales-España, Germán; Algarvio, Hugo; Vries, Laurens de; Faia, Ricardo; Hernandez-Serna, Ricardo; Johanndeiter, Silke; Couto, António; José, Débora Regina S.; Papadaskalopoulos, Dimitrios; Lopes, Fernando; Strbac, Goran; Sanchez, Ingrid; Kochems, Johannes; Helistö, Niina; Chrysanthopoulos, Nikolaos; Estanqueiro, AnaABSTRACT: The goal of this report is to identify in which respects the design and regulation of electricity markets needs to be improved in order facilitate a (nearly) completely decarbonized electricity system. It provides a basis for scoping the modeling analyses that are to be performed in subsequent work packages in the TradeRES project. These simulations will provide the basis for an update of this deliverable in the form of a more precise description of an all-renewable electricity market design. In this first iteration1 of deliverable 3.5, we analyze how the current design of electricity markets may fall short of future needs. Where there is a lack of certainty about the best market design choices, we identify alternative choices. Alternatives may concern a choice between policy intervention and no intervention or different intervention options. Section 2 outlines current European electricity market design and the key pieces of European legislation that underlie it. The European target model is zonal pricing with bidding zones that are defined as geographic areas within the internal market without structural congestion. That implies that within one bidding zone electricity can be traded without considering grid constraints and there are uniform wholesale prices in each zone. The main European markets are Nordpool, EPEX and MIBEL. Trading between zones in the European Price Coupling Region occurs through an implicit auction where price and quantity are computed for every hour of the next day, using EUPHEMIA, a hybrid algorithm for flowbased market coupling that is considered the best practice in Europe at this time.
- Integration of gasification and solid oxide fuel cells (SOFCs) for combined heat and power (CHP)Publication . Costa, Paula; Pinto, Filomena; Andre, Rui N.; Marques, PaulaABSTRACT: This paper reviews the most recent information about the main operations to produce energy from carbonaceous materials, namely biomass and wastes through the integration of gasification, syngas cleaning and solid oxide fuel cells (SOFCs), which have shown to be a good option for combined heat and power (CHP) production, due to high efficiency and low environmental impact. However, some challenges still need to be overcome, mainly when mixed feedstocks with high contents of hazardous contaminants are used, thus syngas cleaning and conditioning is of major importance. Another drawback is SOFC operation, hence new materials especially for the anode has been proposed and tested. An overall process to produce CHP by gasification integration with SOFC is proposed.
- Structure of microbial communities when complementary effluents are anaerobically digestedPublication . Eusebio, Ana; Neves, André; Marques, Isabel PaulaABSTRACT: Olive oil and pig productions are important industries in Portugal that generate large volumes of wastewater with high organic load and toxicity, raising environmental concerns. The principal objective of this study is to energetically valorize these organic effluents-piggery effluent and olive mill wastewater-through the anaerobic digestion to the biogas/methane production, by means of the effluent complementarity concept. Several mixtures of piggery effluent were tested, with an increasing percentage of olive mill wastewater. The best performance was obtained for samples of piggery effluent alone and in admixture with 30% of OMW, which provided the same volume of biogas (0.8 L, 70% CH4), 63/75% COD removal, and 434/489 L CH4/kg SVin, respectively. The validation of the process was assessed by molecular evaluation through Next Generation Sequencing (NGS) of the 16S rRNA gene. The structure of the microbial communities for both samples, throughout the anaerobic process, was characterized by the predominance of bacterial populations belonging to the phylum Firmicutes, mainly Clostridiales, with Bacteroidetes being the subdominant populations. Archaea populations belonging to the genus Methanosarcina became predominant throughout anaerobic digestion, confirming the formation of methane mainly from acetate, in line with the greatest removal of volatile fatty acids (VFAs) in these samples.
- Delignification of Cistus ladanifer Biomass by Organosolv and Alkali ProcessesPublication . Alves Ferreira Caturra, Júnia Aparecida; Lourenço, Ana; Morgado, Francisca; Duarte, Luís C.; Roseiro, Luisa B.; Fernandes, M. C.; Pereira, Helena; Carvalheiro, FlorbelaABSTRACT: Residues of Cistus ladanifer obtained after commercial steam distillation for essential oil production were evaluated to produce cellulose enriched solids and added-value lignin-derived compounds. The delignification of extracted (CLRext) and extracted and hydrothermally pretreated biomass (CLRtreat) was studied using two organosolv processes, ethanol/water mixtures (EO), and alkali-catalyzed glycerol (AGO), and by an alkali (sodium hydroxide) process (ASP) under different reaction conditions. The phenolic composition of soluble lignin was determined by capillary zone electrophoresis and by Py-GC/MS, which was also used to establish the monomeric composition of both the delignified solids and isolated lignin. The enzymatic saccharification of the delignified solids was also evaluated. The ASP (4% NaOH, 2 h) lead to both the highest delignification and enzymatic saccharification (87% and 79%, respectively). A delignification of 76% and enzymatic hydrolysis yields of 72% were obtained for AGO (4% NaOH) while EO processes led to lower delignification (maximum lignin removal 29%). The residual lignin in the delignified solids were enriched in G- and H-units, with S-units being preferentially removed. The main phenolics present in the ASP and AGO liquors were vanillic acid and epicatechin, while gallic acid was the main phenolic in the EO liquors. The results showed that C. ladanifer residues can be a biomass source for the production of lignin-derivatives and glucan-rich solids to be further used in bioconversion processes.
- Preliminary late Miocene palynomorph assemblages from the Quifangondo and Luanda formations, Onshore Kwanza Basin, AngolaPublication . Rodrigues, C.F.; Pereira, Zélia; Mendes, Márcia; Nsungani, P.C.; Fernandes, Paulo; Lopes, Gilda; Duarte, L. V.; Aboelkomsan, W.; Taylor, E.; Tyrrell, M.; Fernando, M. F.; Machado, V.ABSTRACT: A Miocene succession exposed at the Cabo Ledo and Miradouro da Lua sections in the Onshore Kwanza Basin, Angola, was examined for palynology. Palynomorphs of preliminary late Miocene age identified are presented herein. The upper part of the Quifangondo Formation is dated as middle Tortonian in age based on the co-occurrence of the pollen grain Fenestrites spinosus and the dinoflagellate species Selenopemphix armageddonensis. The palynomorph signature indicates a middle neritic marine environment dominated by dinoflagellate cyst taxa. A late Miocene (late Tortonian to Messinian) age is also documented for the first time at the base of the Luanda Formation based on the co-occurrence of the pollen taxa Echitricolporites spinosus, Fenestrites spinosus, Fenestrites longispinosus, Monoporopollenites annulatus, and Retistephanocolpites gracilis. The palynomorph signature of this unit reflects an inner neritic marine (coastal/lagoon transitional) environment dominated by terrestrial palynomorphs and very rare dinoflagellate cyst taxa. The present research contributes data for improving the stratigraphical framework of the Quifangondo and Luanda formations, both of which are recognized as the main potential source rocks and reservoirs of the Post-Salt Paleogene/Neogene Petroleum System of the Kwanza Basin. This significant contribution provides important biostratigraphic and palaeoenvironmental data for defining the vital temporal horizons of these settings in a basin where petroleum exploration is of interest.
- Geologia e Energia [Comunicação oral]Publication . Quental, Lídia; Gonçalves, Pedro; Simões, Teresa; Costa, Paula; Couto, António; de Oliveira, Daniel Pipa Soares; Dias, Ruben Pereira