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A Life Cycle Analysis (LCA) based on ReCiPe 2016 model of a biorefinery case-study was performed. On the basis of an existing Portuguese Anaerobic Digestion plant, the proposed biorefinery hypothesized the use of (i) Maize Cob Waste (MCW) as co-substrate for Anaerobic co-Digestion (AcoD) with Organic Fraction Municipal Solid Waste (OFMSW), (ii) the use of MCW derived activated carbons (ACs) in a H2S removal unit, and (iii) the biogas upgrading to biomethane in a Pressure Swing Adsorption unit. The main aim was to compare the environmental benefits obtained from distinct uses of biogas, specifically the cogeneration of electricity/heat and biomethane production.Three biogas production configurations were considered: (i) AD of standalone hydrolysed OFMSW (hOFMSW); (ii) AcoD of hOFMSW and MCW pre-treated with H2O2 (hOFMSW+PreMCW); and (iii) AcoD of hOFMSW with non-pre-treated MCW (hOFMSW+MCW). The increase of biogas and methane yields obtained with AcoD of hOFMSW+MCW provided an overall better environmental performance than other configurations.The biogas upgrading to biomethane from AcoD of hOFMSW+MCW generated higher environmental impacts than cogeneration, due to the AC production and upgrading processes. If an optimised H2S adsorption capacity is considered, the Fossil Resource Scarcity, Mineral Resource Scarcity, and Global Warming human health impact categories decreased by 20%, 15%, and 17%, respectively, when compared to the base-case upgrading scenario. Further decreases of up to 52%, 23%, and 28% for those impact categories, respectively, are observed when the natural gas used in the OFMSW collection and transportation fleet is substituted by biomethane produced in the biorefinery.

Abstract Recent challenges in solid waste management in Europe are intimately tied to the fulfillment of the prescribed targets of recycling and organic waste recovery in response to the requirements of European Directives. Challenges with characterizing and propagating uncertainty, and validating predictions permeate decision making. In order to retrieve the societal ramifications in decision making, this study integrates the analytic hierarchy process (AHP) and the technique for order performance by similarity to ideal solution (TOPSIS) for alternative screening and ranking to help decision makers in a Portuguese waste management system. To underscore the role of uncertainty in decision making for alternative ranking, a fuzzy interval multi-attribute decision analysis was carried out to aid in environmental policy decisions. While AHP was used to determine the essential weighting factors, screening and ranking was carried out by TOPSIS under uncertainty expressed by using an interval-valued fuzzy (IVF) method. Such an AHP-based IVF-TOPSIS approach driven by a set of weighting factors associated with the selected criteria has been proven useful for final ranking via an iterative procedure. The practical implementation was assessed by a case study in Setubal Peninsula, Portugal for the selection of the best waste management practices under an uncertain environment, which is geared toward the target fulfillment in the future.

Abstract Buildings worldwide account for a surprisingly high 40% of global energy consumption and produce an increasingly large carbon footprint. Future sustainability of the building sector is therefore strongly dependent on the installation of energy efficient technologies. However, even though these technologies are becoming more and more efficient, human behavior still plays a very important role in the overall building energy consumption. In this paper, a model for occupant behavior within the building in relation to energy consumption, along with a building energy consumption model is proposed based on stochastic Markov models. The energy consumption model is used to predict possible energy saving gains from building retrofitting projects. The objective is to ensure the return on investment from these projects. The obtained results demonstrate that the proposed energy consumption model learns occupant behavioral patterns from the building. Additionally, it reliably reproduces them, predicts the building energy consumption and identifies potential areas of energy waste.

Both climate change and biological invasions are among the most serious global environmental threats. Yet mechanisms underlying these eventual interactions remain unclear. The aim of this study was to undertake a comprehensive examination of the physiological and biochemical responses of native (Ruditapes decussatus) and alien-invasive (Ruditapes philippinarum) clams to environmental warming. We evaluated thermal tolerance limits (CTMax), routine metabolic rates (RMRs) and respective thermal sensitivity (Q10 values), critical oxygen partial pressure (Pcrit), heat shock response (HSP70/HSC70 levels), lipid peroxidation (MDA build-up) and antioxidant enzyme [glutathione-S-transferase (GST), catalase (CAT) and superoxide dismutase (SOD)] activities. Contrary to most studies that show that invasive species have a higher thermal tolerance than native congeners, here we revealed that the alien-invasive and native species had similar CTMax values. However, warming had a stronger effect on metabolism and oxidative status of the native R. decussatus, as indicated by the higher RMRs and HSP70/HSC70 and MDA levels, as well as GST, CAT and SOD activities. Moreover, we argue that the alien-invasive clams, instead of up-regulating energetically expensive cellular responses, have evolved a less demanding strategy to cope with short-term environmental (oxidative) stress-pervasive valve closure. Although efficient during stressful short-term periods to ensure isolation and guarantee longer survival, such adaptive behavioural strategy entails metabolic arrest (and the enhancement of anaerobic pathways), which to some extent will not be advantageous under the chronically warming conditions predicted in the future.

The increasing dependency on fossil fuels has driven researchers to seek for alternative energy sources. Renewable energy sources such as sunlight, wind, or water are the most common. However, since the 1990s, other sources for energy production have been studied. The use of microorganisms such as bacteria or archaea to produce energy is currently in great progress. These present several advantages even when compared with other renewable energy sources. Besides the energy production, they are also involved in bioremediation such as the removal of heavy metal contaminants from soils or wastewaters. Several research groups have demonstrated that these organisms are able to interact with electrodes via heme and non-heme iron proteins. Therefore, the role of iron as well as iron metabolism in these species must be of enormous relevance. Recently, the influence of cellular iron regulation by Fur in the Geobacter sulfurreducens growth and ability to produce energy was demonstrated. In this review, we aim to briefly describe the most relevant proteins involved in the iron metabolism of bacteria and archaea and relate them and their biological function with the ability of selected organisms to produce energy.

We investigate the ethanol absorption spectrum in the range 5.64–10.78 eV (220–115 nm), by combining ab initio theoretical and experimental methods in order to provide the most accurate and up-to-date information about the electronic state spectroscopy of ethanol. In particular, absolute cross-section values are reported from high-resolution vacuum ultraviolet (VUV) photoabsorption measurements. The present VUV spectrum reveals several new features not previously reported in the literature, with particular reference to the Rydberg (ndσ, ndσ′ ← (3a′′/13a)), n ≥ 3 members of the Rydberg (ndπ′(a′) ← (3a′′/13a)) and n = 3 members of the Rydberg (npσ′ ← (10a′/12a)) transitions. The experimental absolute photoabsorption cross sections have subsequently been used to calculate the photolysis lifetime of ethanol in the Earth's atmosphere (0–50 km), showing that solar photolysis is expected to be a weak sink at altitudes lower than 40 km to ●OH radical reactions. Potential energy curves for the lowest-lying excited electronic states, as a function of the O–H and the C–OH coordinates, are also obtained employing the equation of motion coupled cluster single and doubles (EOM-CCSD) and time dependant density functional theory (TD-DFT) methods. These show clear dissociation character at inter-nuclear distances greater than 2.0 Å for the R O–H and 2.2 Å for the R C–OH bond lengths, indicating the rather complex multidimensional character of the potential energy surfaces involved.

Char residues produced in the co-pyrolysis of different wastes (plastics, pine biomass and used tyres) were characterized using chemical and toxicity assays. One part of the solid chars was submitted to extraction with dichloromethane (DCM) in order to reduce the toxicity of the char residues by removing organic contaminants. The different volatility fractions present in the extracted char (Char A) and in the raw char (Char B) were determined by progressive weight loss combustion. A selected group of heavy metals (Cd, Pb, Zn, Cu, Hg and As) was determined in both chars. The chars were subjected to the leaching test ISO/TS 21268 - 2, 2007 and the resulting eluates were further characterized by determining a group of inorganic parameters (pH, conductivity, Cd, Pb, Zn, Cu, Hg and As contents) and the concentrations of several organic contaminants (volatile aromatic hydrocarbons and alkyl phenols). An ecotoxicological characterization was also performed by using the bio-indicator Vibrio fischeri. The chemical and ecotoxicological results were analyzed according to the Council Decision 2003/33/CE and the criteria on the evaluation methods of waste ecotoxicity (CEMWE). The results obtained in this work indicated that the extraction with DCM is an effective method for the removal of organic contaminants of high to medium volatility from pyrolysis solid residues, thus decreasing their toxicity potential. Zn can be leached from the chars even after the DCM extraction treatment and can contribute to the ecotoxicity of the eluates obtained from chars. Both chars (treated and non treated with DCM) were classified as hazardous and ecotoxic wastes.

Abstract Projections of energy demand are important for energy security supply and low carbon futures, and usually rely on final energy consumption trends methods, limiting the opportunity for future options. Methods supported by energy services are much preferred to estimate future energy demand, since they are better suited to accomplish end-users needs. Final energy can then be assessed through complementary tools, as technological models, resulting in deeper knowledge on the relation between energy services and technology options. This paper presents a bottom-up methodology to project detailed energy end-uses demand in the Portuguese residential buildings until 2050, aiming to identify the parameters governing energy services demand uncertainty, through a sensitivity analysis. The partial equilibrium TIMES (The Integrated MARKAL-EFOM System) model was used to assess technology options and final energy needs for the range of parameters variations for each end-use, allowing to conclude on the impact of uncertainty of energy services demand in final energy. Main results show that technology can overweight behavioral practices and lifestyle changes for some end-uses as in space heating and lighting. Nevertheless, important focus should be given to uncertain parameters related with consumer behavior, especially those on heating and other electric end-uses, as thermal comfort and equipment's use.

Abstract The objective of this work was to assess the possibility of using biomass ashes as substitutes for cement and natural aggregates in concretes, without compromising their mechanical, chemical, and ecotoxic properties. Thirteen concrete formulations were prepared with different percentages of bottom and fly ashes produced in the power plant of a pulp and paper industry. These formulations were submitted to mechanical compressive strength assays, after 28, 60, and 90 days of cure. The reference formulation (without biomass ashes) and two formulations (with biomass ashes), were selected for further characterization. After 90 days of cure, the selected formulations were submitted to the leaching test described in the EN12457-2 (L/S = 10 L/kg, 24 h batch cycle) by using two leaching agents: a synthetic marine water (ASPM medium) and a synthetic freshwater (ISO 6341 medium). The eluates produced were submitted to chemical characterization (set of 19 metals, pH, SO 4 2 - , F−, dissolved organic carbon, chlorides, phenolic compounds, and total dissolved solids) and to an ecotoxicological characterization (for marine eluates: bioluminescence inhibition of the bacterium Vibrio fischeri; growing inhibition of the microalgae Phaedactilum tricornutum; mobility inhibition of the microcrustacean Artemia franciscana; for freshwater eluates: mobility inhibition of the microcrustacean Daphnia magna; growing inhibition of the microalgae Pseudokirchneriella subcapitata). The substitution of 10% cement by fly ashes has promoted similar to higher levels of the compressive strength to reference formulation. The new formulations presented emission levels of chemical species similar to, or even lower than, those observed for the reference formulation. The ecotoxicological levels were reduced for all of the formulations.