Sabrina Spatari

The contemporary European copper cycle: waste management subsystem

Abstract A comprehensive copper mass balance for waste management in Europe has been carried out, including municipal solid waste, construction and demolition waste, wastes from electrical and electronic equipment (WEEE), and end-of-life vehicles (ELV). The recycling efficiency of the current waste management system in Europe was quantified and the sources of copper scrap used for secondary copper production were determined. Additionally, an assessment of copper losses to the environment from incinerators and landfills was undertaken. As a final step, select parameters were varied to test the sensitivity of copper waste generation results to the uncertainties in the data. The total flows of copper into the European waste management system consists of 920 Gg/y domestic copper waste and of 300 Gg/y imported old scrap, of which 740 Gg/y are recycled and 480 Gg/y are landfilled. In Europe 2 kg per capita of copper waste is generated annually. WEEE and ELV are the most important domestic waste streams from the perspective of copper contents. They contain 67% of the total copper throughput, but only make up 4% of the mass of total waste generation. Because WEEE is the fastest growing waste category, this finding emphasizes the need for efficient WEEE recycling strategies. The overall recycling efficiency for Europe for copper in all types of waste, excluding prompt scrap and scrap imports, is 48%, with a range of 5–58% depending on the country. This shows further potential for increased recycling activities in the future. Emissions of copper to the environment are under 5 Gg/y but several new sources for emissions are not yet quantified. Uncertainties in waste generation rate and composition for some waste categories (WEEE, C&D) are high, and additional analysis is needed to confirm the above findings.

The contemporary European copper cycle: 1 year stocks and flows

Abstract Substance flow cycles can provide a picture of resource uses and losses through a geographic region, allowing us to evaluate regional resource management and estimate gross environmental impacts. This paper traces the flow of copper as it enters and leaves the European economy over 1 year and provides the numerical accounting of copper flows that are further analyzed in a companion paper in this issue. We examine the major flows of copper from ore, as it is extracted from the earth, transformed into products, and discarded or recycled. A regional material flow model was developed to estimate patterns of copper use in the early 1990s in select European countries. Successive mass balance calculations were used to determine copper flows, including the amount of metal that enters use in society and is deposited in waste repositories. A database that records temporal and spatial boundary conditions and data quality was developed for continental substance flow analysis. The majority of copper is mined, smelted, and refined outside of Europe. Across the life cycle, a net total of 1900 Gg/year of copper is imported into Europe. About 40% of cathode copper produced within the system is made from old and new scrap. It is estimated that approximately 8 kg of copper per person enters use in society, largely in infrastructure, buildings, industry, and private households. The majority of copper in finished products is contained in pure form (70%), the remainder in alloy form. The waste management system in Europe recycles about 60% of the copper from waste. The copper discard flow from post-consumer waste is roughly five times higher than that from copper production waste. This ratio would decrease if we consider production wastes generated outside of the European system boundary. The net addition of copper to the stock in society in the system is about 6 kg/person. Given the in-service lifetime of the applications of copper identified in this model, most of the copper processed during the last few decades still resides in society, mostly in non-dissipative uses.

The Multilevel Cycle of Anthropogenic Zinc

Summary A comprehensive annual cycle for stocks and flows of zinc, based on data from circa 1994 and incorporating information on extraction, processing, fabrication, use, discard, recycling, and landfilling, was carried out at three discrete governmental unit levels—54 countries and 1 country group (which together comprise essentially all global anthropogenic zinc stocks and flows), nine world regions, and the planet as a whole. All of these cycles are available in an electronic supplement to this article, which thus provides a metadata set on zinc flows for the use of industrial ecology researchers. A “best estimate” global zinc cycle was constructed to resolve aggregation discrepancies. Among the most interesting results are the following: (1) The accumulation ratio, that is, addition to in-use stock as a function of zinc entering use, is positive and large (2/3 of zinc entering use is added to stock) (country, regional, and global levels); (2) secondary input ratios (fractions of input to fabrication that are from recycled zinc) and domestic recycling percentages (fractions of discarded zinc that are recycled) differ among regions by as much as a factor of six (regional level); (3) worldwide, about 40% of the zinc that was discarded in various forms was recovered and reused or recycled (global level); (4) zinc cycles can usefully be characterized by a set of ratios, including, notably, the utilization efficiency (the ratio of manufacturing waste to manufacturing output: 0.090) and the prompt scrap ratio (new scrap as a fraction of manufacturing input: 0.070) (global level). Because capturable discards are a significant fraction of primary zinc inputs, if a larger proportion of discards were recaptured, extraction requirements would decrease significantly (global level). The results provide a framework for complementary studies in resource stocks, industrial resource utilization, energy consumption, waste management, industrial economics, and environmental impacts.

The contemporary European copper cycle: The characterization of technological copper cycles

Abstract Copper is an example of an anthropogenically utilized material that is of interest to both resource economists and environmental scientists. It is a widely employed industrial metal, and one that in certain forms and concentrations is moderately biotoxic. It is also one that may be potentially supply-limited. A comprehensive accounting of the anthropogenic mobilization and use of copper must treat a series of life stages: mining and processing, fabrication, utilization, and end of life. Reservoirs in which copper resides include the lithosphere, ore and ingot processing facilities, fabricators, at least a dozen major uses, several intentional and default stockpiles, landfills, and the environment. The flow rates among those reservoirs constitute the cycle. If a non-global cycle is being constructed, imports to and exports from the region of interest must also be included. In this paper we discuss the characteristics of each of the components of anthropogenic copper cycles, as well as generic approaches to the acquisition and evaluation of data over space and time. Data quality and data utility are evaluated, noting that information relevant to technology and resource policy is easier to acquire than is information relevant to human health and ecosystem concerns, partly because the spatial scale required by the latter is considerably smaller and the flow rates rarely analyzed and reported. Despite considerable data limitations, we conclude that information is sufficiently available and the data sufficiently accurate to characterize copper cycles at a variety of spatial scales.

Life cycle implications of urban green infrastructure

Low Impact Development (LID) is part of a new paradigm in urban water management that aims to decentralize water storage and movement functions within urban watersheds. LID strategies can restore ecosystem functions and reduce runoff loadings to municipal water pollution control facilities (WPCF). This research examines the avoided energy and greenhouse gas (GHG) emissions of select LID strategies using life cycle assessment (LCA) and a stochastic urban watershed model. We estimate annual energy savings and avoided GHG emissions of 7.3 GJ and 0.4 metric tons, respectively, for a LID strategy implemented in a neighborhood in New York City. Annual savings are small compared to the energy and GHG intensity of the LID materials, resulting in slow environmental payback times. This preliminary analysis suggests that if implemented throughout an urban watershed, LID strategies may have important energy cost savings to WPCF, and can make progress towards reducing their carbon footprint.

The characterization of technological zinc cycles

A comprehensive accounting of the anthropogenic mobilization of zinc must treat a series of life stages: mining and processing, fabrication, utilization, and end of life. Reservoirs in which zinc resides include the lithosphere, ore and ingot processing facilities, at least a dozen major uses, several intentional and default stockpiles, landfills, and the environment. The flow rates among those reservoirs constitute the technological cycle. If a non-global cycle is being constructed, imports to and exports from the region of interest must also be included. In this paper we discuss generic approaches to the acquisition and evaluation of data for each of the components of anthropogenic zinc cycles over space and time. Data quality and data utility are evaluated, noting that information relevant to technology and resource policy is easier to acquire than is information relevant to human health and ecosystem concerns, partly because the spatial scale required by the latter is considerably smaller and the flow rates rarely analyzed and reported. Despite considerable data limitations, we conclude that information is sufficiently available and accurate to permit reasonably quantitative zinc cycles to be characterized at a variety of spatial scales.

Land use greenhouse gas emissions from conventional oil production and oil sands.

Debates surrounding the greenhouse gas (GHG) emissions from land use of biofuels production have created a need to quantify the relative land use GHG intensity of fossil fuels. When contrasting land use GHG intensity of fossil fuel and biofuel production, it is the energy yield that greatly distinguishes the two. Although emissions released from land disturbed by fossil fuels can be comparable or higher than biofuels, the energy yield of oil production is typically 2-3 orders of magnitude higher, (0.33-2.6, 0.61-1.2, and 2.2 5.1 PJ/ha) for conventional oil production, oil sands surface mining, and in situ production, respectively). We found that land use contributes small portions of GHGs to life cycle emissions of California crude and in situ oil sands production ( <0.4% or < 0.4 gCO₂e/MJ crude refinery feedstock) and small to modest portions for Alberta conventional oil (0.1-4% or 0.1-3.4 gCO₂e/MJ) and surface mining of oil sands (0.9-11% or 0.8-10.2 gCO₂e/MJ).Our estimates are based on assumptions aggregated over large spatial and temporal scales and assuming 100% reclamation. Values on finer spatial and temporal scales that are relevant to policy targets need to account for site-specific information, the baseline natural and anthropogenic disturbance.

The contemporary European zinc cycle : 1-year stocks and flows

Abstract A regional material stock and flow (STAF) model was constructed to track the pathway of zinc in the early 1990s in selected western European countries. This paper traces the major flows of zinc from ore, to product, to potential secondary resource as it moves through the European economy over 1 year. Successive mass balance estimations were used to determine zinc flows, including the amount of metal that enters stocks in waste reservoirs and products. A resource-specific model and database were used to allocate zinc flows and record temporal and spatial boundary data and data quality criteria. The model shows that for primary zinc, as for other non-ferrous metals, most is imported as concentrate from North and South America and Oceania, and is smelted in Europe to refined metal. It is estimated that 5 kg zinc per person enters use annually in the European economy; this is partly balanced by a flow to waste management of about 2 kg per capita. The largest flows of zinc in discard streams are in construction and demolition debris and in end-of-life vehicles. Only about 34% of the discarded zinc is recycled. While zincs residence time can be high for many of its applications in the building and construction sector, since the majority of zinc is used as an anti-corrosion coating, there are dissipative losses occurring during the lifetime of products and infrastructure containing zinc. This study and others suggest that zinc losses to the environment are significant in magnitude, and their impacts should be evaluated over time and at various spatial scales.

Using Life Cycle Assessment to Evaluate Green and Grey Combined Sewer Overflow Control Strategies

Decentralized approaches to managing urban stormwater are gaining increased attention within the contexts of urban sustainability, climate change adaptation, and as a means of reducing combined sewer overflows (CSOs). This study applied a life cycle assessment (LCA) to comparing the environmental efficiency of three means of equivalently reducing CSOs to the Bronx River (Bronx, NY, USA). Strategy 1 featured decentralized green infrastructure technologies, while “grey” strategies 2 and 3 detained, and detained and treated, respectively, excess flows at the end of pipe. We estimated greenhouse gas emissions (in metric tons of carbon dioxide equivalents [t CO‐eq]) over the construction, operation, and maintenance phases, including energy consumed at the wastewater treatment plant (WWTP), carbon sequestered, and shading provided by vegetation (in the case of the green approach) over a 50‐year analysis period. The study area comprised the entire drainage area contributing to New York State permitted CSO discharge points associated with the Hunts Point WWTP. The analysis was performed using a hybrid of process and economic input‐output (EIO) LCA methods. The decentralized green strategy outperformed the two grey strategies in terms of this set of environmental metrics. The net emissions of the green strategy over 50 years was 19,000 t CO‐eq, whereas the grey strategies emitted 85,000 t CO‐eq (detention) and 400,000 t CO‐eq (detention and treatment). These results were significantly influenced by the emissions associated with the operation and maintenance activities required for strategies 2 and 3, and the carbon sequestered and shading provided by the vegetation in strategy 1, and suggest that watershed managers who seek to reduce CSOs and reduce carbon footprints would opt for the green approach.

Intelligent Sustainable Design: Integration of Carbon Accounting and Building Information Modeling

Buildings embody and consume among the largest fraction of energy within the built environment, and likewise they are responsible for large emissions of greenhouse gases (GHGs), often referred to as their carbon footprint. From smalland medium-sized buildings to the most energy intensive of structures, architects and engineers are faced with many new challenges in designing and retrofitting buildings for reduced energy and GHG intensity. Engineers and environmental scientists have been examining the embodied energy and related carbon emissions of buildings for more than 40 years (Baird and Chan 1983; Buchanan and Honey 1994; Cole 1998; Venkatarama Reddy and Jagadish 2003; Nassen et al. 2007; Kellenberger and Althaus 2009), yet arguably few undergraduates recognize this research as a basis for sustainable design. As sustainable and “green” design has become more prevalent in the architecture and engineering industries, college graduates must be prepared not only to follow environmental guidelines but also to understand the implications as well. After more than two decades of research into “greening” the design and construction of buildings, many new methods and tools have emerged to meet the energy challenges of the built environment. Residential and commercial buildings in the United States currently consume about 40% of the country’s primary energy and emit 20% of the national carbon dioxide budget (Yeang 1999; Yudelson 2007; Dimoudi and Tompa 2008; U.S. Department of Energy 2009; U.S. Energy Information Administration 2010). Thus, one major focus of sustainable building design is to reduce the carbon intensity of building components as well as lower operational energy demand (Kellenberger and Althaus 2009). Courses that focus on sustainability are becoming integral within higher education as part of greenand sustainable-engineering undergraduate programs (AASHE 2010). Within the civil engineering discipline, life-cycle assessment (LCA) has become an important analytical framework for evaluating the environmental sustainability of civil engineering infrastructure. Moreover, for architectural engineering specifically, building information modeling (BIM) is evolving as a valuable tool for meeting sustainability objectives in building programs. This paper discusses the experience of combining BIM and LCA methods in undergraduate and graduate engineering teaching at Drexel University and the application of commercial BIM and LCA software for teaching sustainable design of buildings.