Author(s): Ian Vázquez Rowe y otros
(Español) Purpose: Life cycle assessment (LCA) and data envelopment analysis (DEA) have been combined in numerous occasions in order to identify the environmental efficiency of multiple units. In many cases, important differences in environmental performance have been identified among the units, referred to as decision-making units (DMUs). However, most studies have been limited to 1 year of assessment, preventing the study from identifying if efficiency values were linked to a specific trend of each DMU through time or to random annual changes. Therefore, the current study delves into the temporal variations in efficiency using DEA. Materials and methods: A DEA window analysis is applied to a set of wastewater treatment plants for a 4-year interval between 2009 and 2012 with the aim of understanding the annual behaviour of WWTPs in terms of environmental sustainability. A set of 47 WWTPs located in different regions of Spain were analysed using a window of 4 years of operation, to account not only for the differences in eco-efficiency between plants but also for changes due to the numerous temporal factors that may affect individual plants. Results: Results extracted from the assessment suggested that for the vast majority of the facilities, the efficiency standards tended to remain constant through time. Statistical tests (i.e. ANOVA and Friedman’s test) confirmed there were no significant differences between years in the different group sizes. This finding, confirmed that the use of the slacks-based measure of efficiency (SBM) model for one single year of operation is a good proxy for the evaluation of the environmental efficiency of these systems. In addition, the scale factor was confirmed as a significant driving force regarding environmental efficiency and significant differences in efficiency values were identified between large and medium WWTPS, on the one hand, and smaller plants, on the other. Conclusions: Significant differences were detected among plants with different legislation thresholds for their effluent withdrawal. WWTP discharging to nonsensitive water bodies appeared to be able to repeatedly attain efficiency values near the benchmark, whereas facilities with stricter thresholds (i.e. sensitive water bodies) struggled to achieve those values, especially in the case of the smaller plants.
Open linkAuthor(s): Ramzy Kahhat Abedrabbo y otros
(Español) International trade of discarded electronics (e-waste) has become a matter of concern over the last decade because of the actual and potential harms associated with their hazardous materials. An initiative under the aegis of the UN called the Best-of-Two-Worlds (Bo2W) philosophy is one solution to the e-waste problem that has gained some traction. Our dual purpose is to examine the ethical grounds of Bo2W and to propose an alternative program for action. We call this alternative ethical electronics repair, reuse, repurposing, and recycling (EER4). To explore the ethical grounds of Bo2W and to articulate EER4 as an alternative, we draw on notions of ethics, technology, and organization developed in science and technology studies (STS) and diverse economies literatures while empirically we explore a mixed methods case study of a small recycling firm in northern Mexico. Conceptually and empirically, our analysis points to a need for a richer imagination of the possibilities for economic action oriented toward managing discarded electronics. More broadly, our findings may act as a reminder that the space between use and discard proliferates the literal and figurative resources for enriching the imagination and enactment of diverse economic possibilities via the action of repair, reuse, repurposing, and recycling.
Open linkAuthor(s): Ian Vázquez Rowe, Ana Lucía Cáceres Cebrecos, Renato Torres García, Isabel Quispe Trinidad, Ramzy Kahhat Abedrabbo
(Español) The production of pisco is concentrated along the southern hyper-arid coast in five producing regions. Despite efforts to regulate its production, the Denomination of Origin still lacks a best practices guideline for producers to follow in terms of choosing technologies and operations that can help towards cleaner production. Hence, the present study aims at analyzing a selected number of pisco wineries using Life Cycle Assessment to compute the environmental impacts of this product in order to identify the systems' hotspots and propose improvement actions. A total of six wineries were assessed, including the viticulture, vinification/distillation and bottling stages. Results, which included 13 impact categories and were reported for a conventional 500 mL pisco bottle, showed that environmental impacts vary substantially depending on the winery assessed. Global warning potential (GWP) results ranged from 1.7 kg CO2eq to 4.0 kg CO2eq. Viticulture operations presented highest environmental burdens in most categories, pushed by the production and on-site emissions of fertilizers in terms of eutrophication, GWP or fossil depletion and by irrigation in the case of water depletion. The bottling stage was also relevant due to the high impacts of glass production, whereas vinification/distillation processes at the winery were dependent on the energy carrier for the distillation. The type of pisco produced, crop maturity or the degree of mechanization triggered the main environmental impact variations that were identified among wineries.
Open linkAuthor(s): Ian Vázquez Rowe, Gustavo Larrea Gallegos y otros
(Español) Purpose: The main goal of this study is to provide a thorough environmental sustainability analysis of the construction, traffic, and maintenance of a 45.6-km section of the ‘Manu Road’, an unpaved tropical road that is currently being built in the vicinity of Manu National Park, in the region of Madre de Dios, Peru. Methods: Life cycle assessment (LCA) using a set of 18 different impact categories was selected to conduct the environmental analysis. Modelling of machinery and vehicle emissions, as well as dust emissions, was performed to account for site-specific characteristics in terms of road construction and traffic. Similarly, direct land use changes were modelled with a particular emphasis on the decay of deforested biomass during construction. A set of different scenarios for the production system were considered to account for uncertainty regarding vehicle transit, amount of deforested biomass, and emission standards. Results and discussion: Construction, maintenance, and traffic of the Manu Road varied considerably depending on methodological assumptions. Deforestation due to direct land use changes appears to be the main environmental hotspot in terms of climate change, whereas in the remaining impact categories, traffic was the main carrier of environmental burdens. Conclusions: To the best of our knowledge, this study is the first LCA that focuses on the construction, maintenance, and traffic in a tropical rainforest environment. Despite the low requirements in terms of materials and technology to build this road, its derived environmental impacts are relevant in terms of climate change and particulate matter formation due to deforestation and dust emissions, respectively. Unpaved roads represent a relevant proportion of the entire road network worldwide, especially in developing tropical countries, playing a crucial role in the transportation of raw materials. Furthermore, road infrastructure is expected to expand explosively in the decades to come. Therefore, we suggest that LCA studies can and should improve the planning of road infrastructure in terms of life cycle inventories.
Open linkAuthor(s): Ramzy Kahhat Abedrabbo, Samy García Torres y otros
(Español) Earthquakes are natural phenomena that can cause severe damage to housing infrastructure and prolonged disruption to society. Depending on their magnitude, epicenter location, local construction characteristics, and many other features, earthquakes may generate large amounts of debris and waste. The large amounts of debris generated after the disaster become one of the main problems for a population facing health issues and the need to reconstruct the city. Proper characterization and quantification of debris, subsequent waste management and reconstruction planning are essential for the restoration of an area affected by an earthquake. This study presents a methodological approach to characterize, quantify and forecast the debris produced as a consequence of earthquakes, as well as the flow of materials required for the reconstruction of the area affected. The proposed methodology includes a residential infrastructure characterization stage, a probabilistic estimation of damage by characterizing the vulnerability functions using CAPRA-GIS tool, and material flow analyses (MFA) for the characterization and quantification of debris associated with the event of an earthquake and for new materials for the reconstruction stage. A case study was developed to test this methodological approach. The residential sector of Tacna, a city with high seismic risk located on the southern coast of Peru, was selected. Moreover, five different construction systems (i.e., reinforced masonry-bearing walls with concrete diaphragms, adobe, wood, concrete shear walls, and straw) used in the residential sector of Tacna were characterized. Also, three possible earthquake scenarios (i.e., 8.6 Mw, 7.5 Mw and 6.2 Mw) were analyzed, each one with three different material end-of-life management situations. Simultaneously, the origin and quantities of new materials needed for the reconstruction of housing infrastructure were determined. The flow of new materials considered productivity rates in the construction and manufacturing sectors. The results show that in the presence of the greatest earthquake (8.6 Mw), adobe and straw homes suffered greatest damage, with damage proportions of 63% and 48%, yielding 27,000 and 1390 tonnes of debris, respectively. Also, 204,000 tonnes of concrete, 7400 tonnes of steel and 461,400 tonnes of clay brick were included as debris generated in this scenario. Furthermore, for all scenarios, the MFA provides an estimate of regional import of materials (e.g., cement, steel, brick and wood) for the reconstruction phase. Finally, the methodology is applicable to developed and undeveloped countries with different housing types, their respective vulnerability functions and constant earthquake recurrence.
Open linkAuthor(s): Isabel Quispe Trinidad, Ramzy Kahhat Abedrabbo y otros
(Español) Rapid population growth and consumption of goods and services imply that demand for energy and resources increases continuously. Energy consumption linked to non-renewable resources contributes to greenhouse gas emissions and enhances resource depletion. In this context, the use of agricultural solid residues such as rice husk, coffee husk, wheat straw, sugar cane bagasse, among others, has been widely studied as an alternative energy source in order to decrease the use of fossil fuels. However, rice husk is among those agricultural residues that are least used to obtain energy in developing countries. Approximately 134 million tonnes of rice husk are produced annually in the world, of which over 90% are burned in open air or discharged into rivers and oceans in order to dispose of them. This review examines the energetic potential of agricultural residues, focused on rice husk. The review describes direct combustion and fast pyrolysis technologies to transform rice husk into energy considering its physical and chemical properties. In addition, a review of existing studies analyzing these technologies from an environmental life cycle thinking perspective, contributing to their sustainable use, is performed.
Open linkAuthor(s): Isabel Quispe Trinidad, Ian Vázquez Rowe, Ramzy Kahhat Abedrabbo y otros
Open linkAuthor(s): Ian Vázquez Rowe y otros
(Español) The new ISO 14045 framework is expected to slowly start shifting the definition of eco-efficiency toward a life-cycle perspective, using Life Cycle Assessment (LCA) as the environmental impact assessment method together with a system value assessment method for the economic analysis. In the present study, a set of 22 wastewater treatment plants (WWTPs) in Spain were analyzed on the basis of eco-efficiency criteria, using LCA and Life Cycle Costing (LCC) as a system value assessment method. The study is intended to be useful to decision-makers in the wastewater treatment sector, since the combined method provides an alternative scheme for analyzing the relationship between environmental impacts and costs. Two midpoint impact categories, global warming and eutrophication potential, as well as an endpoint single score indicator were used for the environmental assessment, while LCC was used for value assessment. Results demonstrated that substantial differences can be observed between different WWTPs depending on a wide range of factors such as plant configuration, plant size or even legal discharge limits. Based on these results the benchmarking of wastewater treatment facilities was performed by creating a specific classification and certification scheme. The proposed eco-label for the WWTPs rating is based on the integration of the three environmental indicators and an economic indicator calculated within the study under the eco-efficiency new framework.
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