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Economic and environmental impact assessments are increasingly being adopted in the design and implementation of emerging systems. However, their emerging nature leads to several assessment challenges that need to be addressed to ensure the validity and usefulness of results in understanding their potential performance and supporting their development. There is the need to (i) account for spatial and temporal variability to allow a broader perspective at an early stage of development; (ii) handle uncertainties to systematically identify the critical factors and their interrelations that drive the results; (iii) integrate environmental and economic results to support sound decision-making based on two sustainability aspects. To address these assessment challenges, this study presents an alternative approach with the following corresponding features: (i) multiple scenario development to conduct an exploratory assessment of the systems under varying conditions and settings, (ii) global sensitivity analysis to identify the main critical factors and their interrelations, and (iii) trade-off and ecoefficiency analysis to integrate the economic and environmental results. The integrated approach is applied to a case study on plasma gasification for solid waste management. The results of the study highlight how the approach allows the identification of the dynamic relations between project settings and surrounding conditions. For example, the choice of gasifying agent largely depends on the background energy system, which dictates the impacts of the process energy requirement and the savings from the substituted energy of the syngas output. Based on these findings, the usefulness and validity of the proposed integrated approach are discussed in terms of how the key assessment challenges are addressed and how it can provide guidance for the development of emerging systems.

Material efficiency measures, such as recycling rates, are often used to set circular economy targets to achieve higher resource efficiency and lower environmental impact. The aim of this study was to identify material efficiency indicators suitable to reflect the environmental performance of waste and recycling systems using PET bottle waste management in three European countries with diverse waste management structures and recycling performance levels. Material flow analysis and life cycle assessment were performed to assess the material efficiency and environmental impacts of each system as a basis to analyze the relation between these two dimensions. PET bottle waste generation was 5.4 kg/person and year (pa) in Austria in 2013, 6.0 kg/pa in Germany in 2017 and 6.9 kg/pa in Serbia in 2015. Out of this waste flow 41%, 91%, and 11% were directed into PET recyclate in Austria, Germany and Serbia, respectively. For all systems, higher material efficiency translated into lower environmental impact and vice versa. However, linear regression analysis between different material efficiency indicators and environmental impacts showed that indicators targeted at actual recycling, specifically at closed loop, were better suited to reflect environmental performance than input-based indicators. Therefore, whenever data are available, output-based quality-related indicators should be used to measure the material efficiency of waste and resource systems because they correlate best with the goals of increasing resource efficiency and decreasing environmental impacts.

Solid waste disposal has led to increasing concerns over resource, health, and environmental problems. These issues have been investigated using the Life Cycle Assessment (LCA) technique which helps identify the roots of varying hazards and allows decision-makers to improve the environmental performance of waste management practices. However, there is a lack of review studies that conducted meta-analysis related to developments in critical methodological steps of LCA on solid waste management. To fill this gap, this review paper examines 15 elements comprising the preference of journals, 13 LCA method-related characteristics, and economic assessment. Insights on the limitations and current practices of LCA applications, along with trends for future research, are provided. 240 studies on the LCA of SWM from 2009 until 2020 were systematically reviewed and classified into two major year-groups (i.e., 2009-2014 and 2015-2020) to investigate the trend changes. Among the studied elements, it is found that energy-related applications are on the increase in LCA studies on solid waste management. Anaerobic digestion facilities nearly double in appearance in the second year-group (2015-2020). There is also a more frequent occurrence of certain characterization methods like ReCiPe and CML. Functional units become more diverse, but are overall mostly defined on a mass basis. A frequently identified issue of many LCAs on solid waste management is the ambiguity of data sources such as out-of-date literature or inconsistent geographical references. By addressing issues of methodological standardization, this review study provides a basis to further increase the reliability of results of future LCA studies on solid waste management.

The present study investigates waste generation during the production and erection phase of a prefabricated single family house in Austria as a basis for identifying waste prevention potentials. Therefore, the material composition of a case study building (wood frame construction) is compared to waste generated during production and erection. In order to assess the whole life cycle of prefabricated buildings the use phase as well as the end-of-life phase are also considered. Examples are given to show how different measures can impact the generation of waste directly and indirectly. The results show that production and erection are already very efficient with regard to waste generation and prevention potentials mainly exist in further offcut reduction and optimization in packaging. The use phase and the end-of-life of the building are more complex to investigate and waste prevention potentials are less tangible. However, important measures for waste reduction are related to the easy exchangeability of building components as well as their reusability. The lifetime extension of the building and building components, which can be achieved through proper operation and maintenance, can be considered a key issue for preventing waste in the building sector.

Single-use and packaging plastic (SUPP) strategies are intended to transform the linear make-use-dispose economy of SUPPs into a more circular, resource-efficient one. The aim of this study was to identify optimal SUPP management concepts from a circular-economy-perspective by assessing the effects of different SUPP strategies on household waste management. Data on the generation and management of SUPP-containing household waste in Germany in 2017 were compiled and a material flow model was established. Regulatory SUPP strategies were translated into scenarios (with effects on waste generation and waste composition) and implemented in the material flow model. The effects on material efficiency, waste generation and lower heating values were evaluated and trade-offs between these target dimensions were identified. In Germany in 2017, 32 kg per person and year of SUPP household waste were generated, of which 28 kg per person and year was packaging waste. From a material efficiency perspective, the combination of banning specific non-packaging SUPPs and optimizing source-separation leads to the maximum increase in final recycling rates of SUPPs in household waste, from 38% to 50%. However, in this scenario the amount of SUPP-containing household waste is hardly reduced as compared to the status quo. The trade-offs observed in different waste management target dimensions highlight the importance of understanding the systemic effects of SUPP strategies on waste management in order to identify optimal solutions from a circular-economy-perspective.

Previous studies showed that resources recovery through landfill mining (LFM) is generally challenging from an economic perspective and that a large share of project costs is related to the external treatment and disposal of bulk process wastes such as combustibles and fines residue. Building on these analyses, this study aims to explore the potential for improving the economy of LFM in Europe by creating value from these bulk process wastes. Specifically, the combustibles are treated through internal incineration with subsequent energy recovery, while fines residue is utilized as construction aggregates. These explored possibilities are investigated considering other varying factors at the site, project, and system levels that cover possible LFM project settings in Europe. A set-based modelling approach is adapted generate multiple LFM scenarios (531,441) and investigate the underlying critical factors that drive the economy of LFM through global sensitivity analysis. Results show that an additional 16% of LFM sce-narios become net profitable, mainly driven by fines residue utilization. Avoided costs for re-landfilling are higher than the revenues from construction aggregates. By contrast, internal incineration is driven by the revenues from recovered energy rather than the avoided gate fee, which is substituted by the costs for building and operating own plants. Overall, the policy conditions remain critical to further improve the economy of LFM in Europe. Recommendations include an inclusive quality standard that relies on pollutant leachability rather than total concentration for higher-value application of fines residue and incentive rather than taxation for producing renewable energy from the combustibles. (c) 2021 Elsevier Ltd. All rights reserved.

Municipal solid waste incineration (MSWI) fly ash constitutes a hazardous waste. The possibilities for managing this waste comprise disposal at underground deposits or at above-ground landfills after cement stabilisation, application of the FLUREC process, thermal treatment in a dedicated furnace or thermal co-treatment together with combustible hazardous waste. A comparative life cycle assessment (LCA) study was conducted in order to assess the environmental impact of these five MSWI fly ash disposal options with regard to two different time horizons (100years, indefinite). The uncertainties of the input parameters were propagated by Monte Carlo simulations (MCS). As could be shown by the discernibility analysis, the FLUREC process has the lowest impact in more than 90% of the MCS results. In case long-term emissions (beyond 100years) are neglected, the second lowest impact is caused by thermal co-treatment in more than 90% of the MCS results. Consideration of long-term emissions indicates the disposal at underground deposits as second best option. Furthermore, it is shown that stabilisation with cement has the second highest and thermal treatment in a dedicated furnace has the highest environmental impact, mostly due to high CO2 emissions. Therefore these two treatment options should be avoided in the future. Besides the comparative evaluation of the different options, it could be shown that uncertainty analysis is useful to determine the relevance of long-term emissions for the ranking of different systems.

In a resource efficient economy, entropy generation must be kept low and high-entropy wastes should be transformed into low-entropy recycled products, thus saving natural resources. Based on this idea, statistical entropy analysis (SEA) was put forward as a method to evaluate material flow systems with respect to their ability to concentrate or dilute a substance throughout its life cycle using a single metric, relative statistical entropy (RSE). Whereas its application has so far been restricted to highly aggregated material flow systems or to assessments at plant or process level, in the present study the SEA method was adapted to assess the efficiency of resource use in material flow systems which consist of numerous resource flows and include multiple recycling loops. Phosphorus (P) use in Austria served as a case study to illustrate SEA-based resource efficiency assessment for different scenarios and over time. The evaluation enabled exploiting the outcomes of existing P flow studies in a straightforward way and produced additional insights related to the characteristics of resource use within the system. Changes in P management over time had a significant effect on the resource efficiency of P use. The RSE increased by 40% due to P use in Austria in the year 2000 compared to an increase of 30% in 2010. The generally favorable trend of statistical entropy (lower dissipation) in 2010 could be attributed mainly to lower dissipative emissions, more efficient bio-industry, and increasing P removal rates in waste water treatment, which overcompensated the negative impact of the ban of recycling of meat and bone meal (in 2001) on P use efficiency. Further, the SEA-based assessment applied to a scenario of optimized P management reflected the positive effects of measures to reduce emissions, enhance recycling, and reduce consumption of P on resource efficiency (50% lower RSE increase in the target system compared to the original state). In synthesis, this study shows that the SEA method is able to integrate various dimensions of resource use into a single indicator, which can serve as a basis to assess and improve the resource efficiency of macro-scale material flow systems.

Dynamic material flow analysis enables the forecasting of secondary raw material potential for waste volumes in future periods, by assessing past, present, and future stocks and flows of materials in the anthroposphere. Analyses of waste streams of buildings stocks are uncertain with respect to data and model structure. Wood construction in Viennese buildings serve as a case study to compare different modeling approaches for determining end‐of‐life (EoL) wood and corresponding contaminant flows (lead, chlorine, and polycyclic aromatic hydrocarbons). A delayed input and a leaching stock modeling approach are used to determine wood stocks and flows from 1950 until 2100. Cross‐checking with independent estimates and sensitivity analyses are used to evaluate the results’ plausibility. In the situation of the given data in the present case study, the delay approach is a better choice for historical observations of EoL wood and for analyses at a substance level. It has some major drawbacks for future predictions at the goods level, though, as the durability of a large number of historical buildings with considerably higher wood content is not reflected in the model. The wood content parameter differs strongly for the building periods and has therefore the highest influence on the results. Based on this knowledge, general recommendations can be derived for analyses on waste flows of buildings at a goods and substance level.

Closing regional material cycles by efficient use of secondary raw materials is a prioritized goal of European politics and industry. The extent to which material cycles may be closed at a regional level has, however, hardly been investigated so far, and mostly without consideration of material quality. Thus, in the present study quality aspects of aluminium (Al) recycling in Austria with respect to alloy composition are investigated in order to identify potential limitations for future Al recycling. Therefore, a dynamic material flow analysis of wrought and cast alloys is carried out for Austria covering the time span from 1964 to 2050. A closed system perspective is introduced with respect to future Al scrap supply and to which degree it can satisfy Al demand associated with final consumption. Results indicate that if current recycling practice is retained, a surplus of mixed Al scrap over final cast Al demand is expected around 2045. Assuming a more intensive use of Al in the transport sector (light-weight construction material), this surplus is likely to occur already in 2030. Model results further indicate that intensive sorting of mixed scraps from end-of-life vehicle treatment represents an effective measure to prevent a surplus of mixed Al scrap. In practice, i.e. in an open economy, the high level of Al scrap imports and exports impairs the evaluation of quality-induced Al recycling constraints, as observed in the model. Nevertheless, lower specific prices of scrap exports from Austria compared to imports may indicate a net import of higher quality scrap to satisfy quality requirements associated with the high share of wrought alloys in secondary production. Therefore, apart from enhanced scrap sorting, international scrap trade is a key element to bring together scrap supply with the scrap demand for the needs of secondary production.

Plastics have been increasingly used in a wide range of applications, generating important waste streams, but overall information on their flows through society is generally not available. Therefore, the national plastic flows in Austria were analyzed and quantified from the production stage up to the waste management stage, for the reference year of 2010. To achieve this, material flow analysis was used to set up a model quantitatively describing the Austrian plastics budget, and the quality of the data sources was assessed using uncertainty characterization. The results show that about 1.1 million tonnes (132 kg/cap·a ± 2%) of primary plastics were produced in Austria, whereas about 1.3 million tonnes (156 kg/cap·a ± 5%) of plastics products were consumed. Roughly one third of the consumed amount contributed to net stock increase in all consumption sectors, and about half of this increase occurred in building and construction, whereas packaging waste constituted approximately half of total post-consumer wastes (70 kg/cap·a ± 4%). Of the total waste amount (including traded and production waste, 91 kg/cap·a ± 3%), the majority was incinerated in waste-to-energy plants or in the cement industry (46% and 21% respectively), whereas the rest was mainly recycled mechanically or chemically (21% and 10% respectively). The results identify the major national flows and processes of plastics, and evaluate the overall data availability for quantifying these flows. Furthermore, the increasing amounts of plastic wastes, due to large stocks having been built up in sectors with long product lifetimes, necessitate assessing which processing capacities are needed and which treatment priorities are to be set in waste management.

Material flow analysis is used to quantify the material turnover of a defined system, relying on data about flows and stocks from different sources with varying quality. In this study, the belief that the available data are representative for the value of interest is expressed via fuzzy sets, specifying the possible range of values of the data. A possibilistic framework for data reconciliation in MFA was developed and applied to a case study on wood flows in Austria. The framework consists of a data characterisation and a reconciliation step. Membership functions are defined based on the collected data and data quality assessment. Possible ranges and consistency levels (quantifying the agreement between input data and balance constraints) are determined. The framework allows problematic data and model weaknesses to be identified and can be used to illustrate the trade-off between confidence in the data and the consistency levels of resulting material flows.

Summary A method for quantitative evaluation of data quality in regional material flow analysis (MFA) is presented. The principal idea is that data quality is a multidimensional problem that cannot be judged by individual characteristics such as the data source, given that data from official statistics may not be per se of good quality and expert estimations may not be per se of bad quality, respectively. It appears that MFA data are never totally accurate and may have certain defects that impair the quality of the data in more than one dimension. The concept of MFA information defects is introduced, and these information defects are mathematically formalized as functions of data characteristics. They are quantified on a scale from 0 (no information defect) to 1 (maximum information defect). The proposed method is illustrated in a case study on palladium flows in Austria. A quantitative evaluation of data quality provides opportunities for understanding and assessing MFA results, their a priori information basis, their reliability in decision making, and data uncertainties. It is a formal step toward better reproducibility and more transparency in MFA.

Various recent policy initiatives indicate an increasing need for a comprehensive overview of potentially extractable anthropogenic resources, in order to compare them with geogenic resources. Therefore, a method has been developed to evaluate and classify anthropogenic resource deposits and to prioritize potential extraction projects in a transparent manner. In this study we present how anthropogenic resources can be systematically integrated into the United Nations Framework Classification for Fossil Energy and Mineral Reserves and Resources 2009 (UNFC-2009). The main goal is to illustrate different settings of anthropogenic resource classification, and to provide specific criteria to map different types of anthropogenic resources within the three dimensions of UNFC-2009, i.e. “knowledge on composition and extractable material content”, “technical and project feasibility” and “socioeconomic viability”. Projects for recovering materials from an old landfill, from obsolete PCs (personal computers), and from in-use wind turbines are exemplarily evaluated and classified under UNFC-2009. The economic results depend on the respective scenarios, where the timing of mining is varied, different organizational and societal settings are compared and different choices for technological options are made. While landfill mining under current conditions is not economically viable, the final result might look different in the future with changing key modifying factors, such as increasing secondary raw material prices. Mining materials from obsolete PCs and from permanent magnets in in-use wind turbines would both yield positive economic results for all investigated scenarios.

In light of various policy initiatives promoting the efficient use of resources, this study investigates how anthropogenic resources could be classified under the United Nations Framework Classification for Fossil Energy and Mineral Reserves and Resources 2009 (UNFC-2009). Compared to geogenic resources, anthropogenic deposits are more heterogeneous and subject to various dynamics, due to the human impact on their genesis. Often they must be assessed not only under aspects of resource recovery, but with respect to alternative waste treatment and disposal options. Factors, which are influencing the classification of anthropogenic resources, vary during the individual phases of resource classification, namely prospection, exploration and evaluation. During the (pre)prospection phase, the preconditions defining the setting for the following resource classification are checked, i.e. the deposit's status of availability for mining (“in-use stocks”, “obsolete stocks” or “waste flows”) as well as the specific handling and mining condition. System variables, which determine the potentially extractable amount of materials, play a major role during the exploration phase, e.g. technological choices for recovery. In the evaluation phase, modifying factors with direct impact on the project's economics are investigated, such as prices for secondary products, (avoided) costs and possibly monetized externalities. Challenges and potentials of classifying different types of anthropogenic resources under UNFC-2009 are illustrated for two different cases: Mining an old landfill (obsolete stock) is contrasted in a qualitative discussion to mining E-waste (waste flow). Finally, an operative evaluation procedure is outlined, which is still to be refined and illustrated via case studies.

Landfill mining (LFM) is a strategy to mitigate environmental impacts associated with landfills, while simultaneously recovering dormant materials, energy carriers, and land resources. Although several case study assessments on the economy of LFM exist, a broader understanding of the driving factors is still lacking. This study aims at identifying generically important factors for the economy of LFM in Europe and understanding their role in developing economically feasible projects in view of different site, project and system-level conditions. Therefore, a set-based modeling approach is used to establish a large number (531,441) of LFM scenarios, evaluate their economic performance in terms of net present value (NPV), and analyze the relationships between input factors and economic outcome via global sensitivity analysis. The scenario results range from -139 Euro to +127 Euro/Mg of excavated waste, with 80% of the scenarios having negative NPVs. Variations in the costs for waste treatment and disposal and the avoided cost of alternative landfill management (i.e. if the landfill was not mined) have the strongest effect on the scenario NPVs, which illustrates the critical role of system level factors for LFM economy and the potential of policy intervention to incentivize LFM. Consequently, system conditions should guide site selection and project development, which is exemplified in the study for two extreme regional archetypes in terms of income and waste management standard. Future work should further explore the developed model to provide decision support on LFM strategies in consideration of alternative purposes, stakeholders, and objectives. (C) 2019 Elsevier Ltd. All rights reserved. Funding Agencies|European Cooperation for Science and Technology - Mining the European Anthroposphere (COST-Action MINEA) [CA15115]; Christian Doppler Laboratory for Anthropogenic Resources; European Training Network for Resource Recovery Through Enhanced Landfill Mining (NEW-MINE) [721185]

Summary Dynamic material flow analysis (MFA) provides information about material usage over time and consequent changes in material stocks and flows. In order to understand the effect of limited data quality and model assumptions on MFA results, the use of sensitivity analysis methods in dynamic MFA studies has been on the increase. So far, sensitivity analysis in dynamic MFA has been conducted by means of a one-at-a-time method, which tests parameter perturbations individually and observes the outcomes on output. In contrast to that, variance-based global sensitivity analysis decomposes the variance of the model output into fractions caused by the uncertainty or variability of input parameters. The present study investigates interaction and time-delay effects of uncertain parameters on the output of an archetypal input-driven dynamic material flow model using variance-based global sensitivity analysis. The results show that determining the main (first-order) effects of parameter variations is often sufficient in dynamic MFA because substantial effects attributed to the simultaneous variation of several parameters (higher-order effects) do not appear for classical setups of dynamic material flow models. For models with time-varying parameters, time-delay effects of parameter variation on model outputs need to be considered, potentially boosting the computational cost of global sensitivity analysis. Finally, the implications of exploring the sensitivities of model outputs with respect to parameter variations in the archetypical model are used to derive model- and goal-specific recommendations on choosing appropriate sensitivity analysis methods in dynamic MFA.

The environmental performance of the waste management system of plastic packaging in Austria was assessed using a combination of high-resolution material flows and input-dependent life cycle inventory data. These data were used to evaluate different configurations of the waste management system, reflecting the system structure as it was in 1994 in Austria and still is in some of the new EU member states, as well as a situation achieving the increased circular economy targets to be met by 2030. For the latter, two options, namely single-polymer recycling and mixed-polymer recycling, were investigated. The results showed that the status quo achieves net benefits for 15 out of 16 impact categories evaluated. Regarding the alternative scenarios, for most impact categories these benefits increased with increasing recycling rates, although for four impact categories the highest net benefit was achieved by the status quo. For many impact categories the marginal environmental benefit decreased at higher recycling rates, indicating that there is an environmentally optimal recycling rate below 100%. The results also highlight the importance of high-quality single-polymer plastics recycling from an environmental perspective because utilizing mixed polymer recycling to achieve circular economy targets would result in lower environmental benefits than the status quo.

Bisphenol A (BPA) is an industrial chemical used as an additive in conventional point-of-sale thermal paper receipts. Due to BPA being an endocrine disruptor and a substance of very high concern, the European Union (EU) has proposed to ban its use in thermal paper from 2020. Potential similarities in toxicological profiles have raised concerns that the use of bisphenol S (BPS) as a substitute for BPA may result in yet another situation of a problematic chemical being distributed in consumer products. This study provides a comprehensive evaluation of the current knowledge of BPA and BPS use in thermal paper and, based on dynamic material and substance flow modeling, quantifies potential effects of the BPA ban on future BPA and BPS flows within the European paper cycle. Based on available data and the modeling of BPA and BPS flows, approximately 200 t of BPS are estimated to be present in the current European paper cycle. The modeling further demonstrated that by substituting 50% of BPA, BPS amounts in the European paper cycle would increase more than fivefold over a modeling period of 60 years. In the same time, more than 90 t of BPA would still be circulated in European paper products. BPA alternatives other than BPS should receive additional attention, as very limited quantitative data currently exist. The results of this study quantitatively demonstrate that chemical bans alone are not sufficient to ensure clean material cycles, and so the effective regulation of potential substitutes needs to be implemented in parallel.

In order to promote sustainable production by using secondary raw material from existing material stocks, complementary to primary raw material, information about the future availability of secondary resources constitutes a prerequisite. In this study, a dynamic material flow model of historic aluminium (Al) flows in Austria is combined with forecasts on future Al consumption to estimate the development of old scrap generation and in-use stocks until 2050. In-use stocks are estimated to increase by 60 % to 515 kg/cap. by 2050 assuming a scenario of moderate economic growth. Old scrap generation in 2050 would thereby more than double (up to 30 kg/cap.) in comparison to the 2010 amounts. Despite this substantial increase in old scrap generation, industrial self-supply from old scrap will probably not exceed 20 %, and final consumption self-supply of Al will not exceed 40 % given present conditions. Opportunities and limits of increasing self-supply through higher collection rates and lower scrap export levels are investigated in this study as the European Raw Material Initiative considers enhanced recycling to be a key measure to ensure future resource supply. Based on these analyses, a self-sustaining Al supply from post-consumer Al is not expected if current trends of Al usage continue. Therefore, comprehensive resource policy should be based on a profound understanding of the availability of primary and secondary resources potentials and their dynamics.

Material flow analysis (MFA) is widely used to investigate flows and stocks of resources or pollutants in a defined system. Data availability to quantify material flows on a national or global level is often limited owing to data scarcity or lacking data. MFA input data are therefore considered inherently uncertain. In this work, an approach to characterize the uncertainty of MFA input data is presented and applied to a case study on plastics flows in major Austrian consumption sectors in the year 2010. The developed approach consists of data quality assessment as a basis for estimating the uncertainty of input data. Four different implementations of the approach with respect to the translation of indicator scores to uncertainty ranges (linear- vs. exponential-type functions) and underlying probability distributions (normal vs. log-normal) are examined. The case study results indicate that the way of deriving uncertainty estimates for material flows has a stronger effect on the uncertainty ranges of the resulting plastics flows than the assumptions about the underlying probability distributions. Because these uncertainty estimates originate from data quality evaluation as well as uncertainty characterization, it is crucial to use a well-defined approach, building on several steps to ensure the consistent translation of the data quality underlying material flow calculations into their associated uncertainties. Although subjectivity is inherent in uncertainty assessment in MFA, the proposed approach is consistent and provides a comprehensive documentation of the choices underlying the uncertainty analysis, which is essential to interpret the results and use MFA as a decision support tool. [ABSTRACT FROM AUTHOR]

Solid residues generated at European Waste to Energy plants contain altogether about 69,000 t/a of Zn, of which more than 50% accumulates in air pollution control residues, mainly boiler and filter ashes. Intensive research activities aiming at Zn recovery from such residues recently resulted in a technical scale Zn recovery plant at a Swiss waste incinerator. By acidic leaching and subsequent electrolysis this technology (FLUREC) allows generating metallic Zn of purity>99.9%. In the present paper the economic viability of the FLUREC technology with respect to Zn recovery from different solid residues of waste incineration has been investigated and subsequently been categorised according to the mineral resource classification scheme of McKelvey. The results of the analysis demonstrate that recovery costs for Zn are highly dependent on the costs for current fly ash disposal (e.g. cost for subsurface landfilling). Assuming current disposal practice costs of 220€/ton fly ash, resulting recovery costs for Zn are generally higher than its current market price of 1.6€/kg Zn. With respect to the resource classification this outcome indicates that none of the identified Zn resources present in incineration residues can be economically extracted and thus cannot be classified as a reserve. Only for about 4800 t/a of Zn an extraction would be marginally economic, meaning that recovery costs are only slightly (less than 20%) higher than the current market price for Zn. For the remaining Zn resources production costs are between 1.5 and 4 times (7900 t/a Zn) and 10-80 times (55,300 t/a Zn) higher than the current market value. The economic potential for Zn recovery from waste incineration residues is highest for filter ashes generated at grate incinerators equipped with wet air pollution control.

The goal of this study is to apply the natural resource classification framework UNFC-2009 to a landfill-mining project to identify the landfilled materials as potential anthropogenic ‘resources’ (reasonable prospects for eventual economic extraction in the foreseeable future) or ‘reserves’ (current economic extraction possible), and to reveal critical factors for the classification of the project. Based on data from a landfill-mining project in Belgium, the focus of the evaluation was set on technological options and economics, with a material flow analysis quantifying relevant material and energy flows and a discounted cash flow analysis including Monte Carlo simulations, exploring the project's socioeconomic viability. Four scenarios have been investigated, representing different alternatives for the combustible waste fraction's thermal treatment (gas-plasma technology vs. incineration) and for specific stakeholder interests (public vs. private perspective). The net present values were found to be negative for all four scenarios, implying that none of the project's variations is currently economically viable. The main drivers of the economic performance are parameters related to the thermal treatment of the combustible waste fraction as well as to the sales of recovered metals. Based on required future price increases for non-ferrous metals or electricity to make the project economically viable, the scenarios resulted in different final resource classifications. Although the applicability of UNFC-2009 to landfill mining has been proven successfully, further research is needed to define generally suitable criteria for categorizing various kinds of anthropogenic resources under UNFC-2009. This will allow for fair comparisons between naturally occurring and anthropogenic resource deposits.

Material flow analysis (MFA) is a widely applied tool to investigate resource and recycling systems of metals and minerals. Owing to data limitations and restricted system understanding, MFA results are inherently uncertain. To demonstrate the systematic implementation of uncertainty analysis in MFA, two mathematical concepts for the quantification of uncertainties were applied to Austrian palladium (Pd) resource flows and evaluated: (1) uncertainty ranges expressed by fuzzy sets and (2) uncertainty ranges defined by normal distributions given as mean values and standard deviations. Whereas normal distributions represent the traditional approach for quantifying uncertainties in MFA, fuzzy sets may offer additional benefits in relation to uncertainty quantification in cases of scarce information. With respect to the Pd case study, the fuzzy representation of uncertain quantities is more consistent with the actual data availability in cases of incomplete databases, and fuzzy sets serve to highlight the effect of uncertainty on resource efficiency indicators derived from the MFA results. For both approaches, data reconciliation procedures offer the potential to reduce uncertainty and evaluate the plausibility of the model results. With respect to Pd resource management, improved formal collection of end-of-life (EOL) consumer products is identified as a key factor in increasing the recycling efficiency. In particular, the partial export of EOL vehicles represents a substantial loss of Pd from the Austrian resource system, whereas approximately 70% of the Pd in the EOL consumer products is recovered in waste management. In conclusion, systematic uncertainty analysis is an integral part of MFA required to provide robust decision support in resource management

In dieser Studie wird das Klassifikations-Modell fur Primarressourcen „United Nations Framework Classification for Fossil Energy and Mineral Reserves and Resources 2009“ (UNFC-2009) auf ein Deponieruckbauprojekt in Belgien angewendet, um die deponierten Materialien als potenzielle anthropogene „Ressourcen“ (begrundete Aussicht auf wirtschaftliche Gewinnung in absehbarer Zukunft) oder „Reserven“ (aktuelle wirtschaftliche Extraktion moglich) zu identifizieren. Daruber hinaus sollen kritische Faktoren fur die Wirtschaftlichkeit des Projektes und damit auch fur die Klassifizierung unter UNFC-2009 aufgezeigt werden.

Die vorliegende Studie hat zum Ziel, den osterreichischen Kunststoffhaushalt sowohl quantitativ (Mengenflusse) als auch qualitativ (Polymertyp, Additive) mithilfe der Methode der Stoffflussanalyse zu beschreiben. Als erster Schritt wurde dazu ein Stoffflussmodell des Kunststoffhaushaltes Osterreichs fur das Jahr 2010 erstellt. Ein Vergleich mit bereits bestehenden Studien fur die Jahre 1994 und 2004 zeigt, dass sich die Primarproduktion, Verarbeitung zu Halbzeugen bzw. der Einsatz von Kunststoff in zehn ausgewahlten Konsumsektoren in den letzten ca. 20 Jahren mengenmasig kaum verandert hat. Die Konsumsektoren Verpackung (30 %), Bau- und Infrastruktur (18 %) als auch Nicht-Kunststoffanwendungen (20 %) wie Lacke und Farben auf Polymerbasis, zahlen heute wie damals zu den wichtigsten Anwendungssektoren. Grose Lagerzuwachse waren vor allem im Bausektor zu verzeichnen, gefolgt von anderen Anwendungen (Freizeitgerate, Buroartikel), dem Mobelsektor und dem Transport- und Elektroniksektor. Aufgrund der langen Lebensdauer von Produkten im Baubereich fallen diese aber erst zu einem spateren Zeitpunkt als Abfall an und machen sich daher in der Abfallwirtschaft im Jahr 2010 noch nicht bemerkbar. Hier stellen kurzlebige Verpackungen den grosten Massenfluss dar. Aufgrund groserer Einsatzmengen und ebenfalls kurzlebigerer Produkte sind im Vergleich zu 1994 und 2004 Anstiege der Menge an Abfall aus den Sektoren Landwirtschaft und Medizin zu erkennen. Auf die Verwertung von Kunststoffabfallen hatte die Deponieverordnung durch das Verbot der Deponierung von organikhaltigen Abfallen ab dem Jahr 2004 einen masgeblichen Einfluss. Wurden 1994 noch 80 % der Kunststoffabfalle deponiert, sind es heute nur ca. 2 % der gesamten Kunststoffabfalle, die in Form von MBA-Reststoffen auf die Deponie gelangen. Zudem werden 18 % stofflich oder in der Stahlindustrie recycelt und die verbleibenden 80 % thermisch verwertet. Die Quantifizierung des Kunststoffhaushaltes im Jahr 2010 macht deutlich, dass die Datengrundlage in Bezug auf Inputstrome an Kunststoffen in die Konsumsektoren (Produktionsdaten) als sehr unzureichend zu bezeichnen ist. Auserdem lassen sich die Kunststofflager in den einzelnen Sektoren nur mit grosen Unsicherheiten abschatzen. Da die Kenntnis der Lager und ihrer Dynamik jedoch fur die Vorhersage der Quantitat und Qualitat zukunftiger Abfallstrome wesentlich ist, sollen in einem nachsten Schritt dynamische Modelle und entsprechende Prognosen erstellt werden.

Basierend auf der Methode der Stoffflussanalyse (SFA) wurde fur das Bilanzjahr 2010 ein statisches Modell der osterreichischen Aluminiumflusse erstellt. Dabei erfolgte eine detaillierte Betrachtung samtlicher Stufen der Aluminiumnutzung, von Produktion und Verarbeitung uber die Nutzungsphase bis hin zur Sammlung und Verwertung von Aluminium (Al). Die Modellergebnisse zeigen einen nationalen Al-Verbrauch von 185 kt/a bzw. 22 kg pro Einwohner und Jahr und eine jahrliche Altschrottmenge von ca. 60 kt/a (7 kg/(EW.a)), wobei 20 % aufgrund von Verlusten in der Abfallwirtschaft nicht wiedergewonnen werden. Zusatzlich zu den 60 kt/a an gesammeltem Altschrott werden national 51 kt/a an gehandeltem Neuschrott und 61 kt/a an internem Neuschrott generiert. Demgegenuber steht ein Schrottverbrauch der Sekundaraluminiumindustrie von 310 kt/a, der zu uber 40 % durch Schrottimporte gedeckt wird. Aus der Bilanzierung des Gesamtsystems ergibt sich schlussendlich ein Zuwachs des in Nutzung befindlichen Al-Lagers von 92 kt/a bzw. 11 kg/a pro Person. Zusatzlich zu einer detaillierten Analyse des aktuellen Systems zeigt diese Arbeit die derzeitigen Moglichkeiten, aber auch die Grenzen – vor allem aufgrund fehlender bzw. nicht verfugbarer Daten – bei der Erstellung nationaler Stoffbilanzen auf. Generell lasst sich aus den Ergebnissen der Arbeit ableiten, dass fur ein zukunftig verbessertes Management von Sekundarrohstoffen eine integrierte Betrachtung nationaler Stoffkreislaufe ebenso von Bedeutung ist wie die Erhebung und Implementierung von Daten betreffend Materialqualitaten (z. B. Legierungen).

Municipal solid waste landfills pose a threat on environment and human health, especially old landfills which lack facilities for collection and treatment of landfill gas and leachate. Consequently, missing information about emission flows prevent site-specific environmental risk assessments. To overcome this gap, the combination of waste sampling and analysis with statistical modeling is one option for estimating present and future emission potentials. Optimizing the tradeoff between investigation costs and reliable results requires knowledge about both: the number of samples to be taken and variables to be analyzed. This article aims to identify the optimized number of waste samples and variables in order to predict a larger set of variables. Therefore, we introduce a multivariate linear regression model and tested the applicability by usage of two case studies. Landfill A was used to set up and calibrate the model based on 50 waste samples and twelve variables. The calibrated model was applied to Landfill B including 36 waste samples and twelve variables with four predictor variables. The case study results are twofold: first, the reliable and accurate prediction of the twelve variables can be achieved with the knowledge of four predictor variables (Loi, EC, pH and Cl). For the second Landfill B, only ten full measurements would be needed for a reliable prediction of most response variables. The four predictor variables would exhibit comparably low analytical costs in comparison to the full set of measurements. This cost reduction could be used to increase the number of samples yielding an improved understanding of the spatial waste heterogeneity in landfills. Concluding, the future application of the developed model potentially improves the reliability of predicted emission potentials. The model could become a standard screening tool for old landfills if its applicability and reliability would be tested in additional case studies.

Based on the method of material flow analysis (MFA), a static model of Austrian aluminum (Al) flows in 2010 was developed. Extensive data research on Al production, consumption, trade and waste management was conducted and resulted in a detailed model of national Al resources. Data uncertainty was considered in the model based on the application of a rigorous concept for data quality assessment. The model results indicated that the growth of the Austrian “in-use” Al stock amounts to 11 ± 3.1 kg yr −1 cap −1 . The total “in-use” Al stock was determined using a bottom-up approach, which produced an estimate of 260 kg Al cap −1 . Approximately 7 ± 1 kg of Al yr −1 cap −1 of old scrap was generated in 2010, of which 20% was not recovered because of losses in waste management processes. Quantitatively, approximately 40% of the total scrap input to secondary Al production originated from net imports, highlighting the import dependency of Austrian Al refiners and remelters. Uncertainties in the calculation of recycling indicators for the Austrian Al system with high shares of foreign scrap trade were exemplarily illustrated for the old scrap ratio (OSR) in secondary Al production, resulting in a possible range of OSRs between 0 and 66%. Overall, the detailed MFA in this study provides a basis to identify resource potentials as well as resource losses in the national Al system, and it will serve as a starting point for a dynamic Al model to be developed in the future.

Plastics, especially from packaging, have gained increasing attention in waste management, driving many policy initiatives to improve the circularity of these materials in the economy to increase resource efficiency. In this context, the EU has proposed increasing targets to encourage the recycling of (plastic) packaging. To accurately calculate the recycling rates, detailed information on the flows of plastic packaging is needed. Therefore, the aim of this paper is to quantitatively and qualitatively investigate the waste management system for plastic packaging in Austria in 2013 using material flow analysis, taking into account the used product types and the polymer composition. The results show that 300,000 ± 3% t/a (35 kg/cap·a) of waste plastic packaging were produced, mainly composed of large and small films and small hollow bodies, including PET bottles. Correspondingly, the polymer composition of the waste stream was dominated by LDPE (46% ± 6%), PET (19% ± 4%) and PP (14% ± 6%). 58% ± 3% was collected separately, and regarding the final treatment, 26% ± 7% of the total waste stream was recovered as re-granulates, whereas the rest was thermally recovered in waste-to-energy plants (40% ± 3%) and the cement industry (33% ± 6%). The targets set by the EU and Austria were reached comfortably, although to reach the proposed future target major technological steps regarding collection and sorting will be needed. However, the current calculation point of the targets, i.e. on the input side of the recycling plant, is not deemed to be fully in line with the overall objective of the circular economy, namely to keep materials in the economy and prevent losses. It is therefore recommended that the targets be calculated with respect to the actual output of the recycling process, provided that the quality of the output products is maintained, to accurately assess the performance of the waste management system.

Summary Material flow analysis is a tool that is increasingly used as a foundation for resource management and environmental protection. This tool is primarily applied in a static manner to individual years, ignoring the impact of time on the material budgets. In this study, a detailed multiyear model of the Austrian phosphorus budget covering the period 1990–2011 was built to investigate its behavior over time and test the hypothesis that a multiyear approach can also contribute to the improvement of static budgets. Further, a novel method was applied to investigate the quality and characteristics of the data and quantify the uncertainty. The degree of change between the budgets was assessed and showed that approximately half of the flows have changed significantly and, at times, abruptly since 1990, but it is not possible to distinguish unequivocally between constant and moderately changing flows given their uncertainty. The study reveals that the phosphorus transported in waste flows has increased more rapidly than its recovery, which accounted for 55% to 60% of the total waste phosphorus in 1990 and only 40% in 2011. The loss ratio in landfills and cement kilns has oscillated in the range of 40% to 50%. From a methodological point of view, the multiyear approach has broadened the conceptual model of the budget, making it more suitable as a basis for material accounting and monitoring. Moreover, the analysis of the data reconciliation process over a long period of time proved to be a useful tool for identifying systematic errors in the model.

Material flow analysis (MFA) is a tool to investigate material flows and stocks in defined systems as a basis for resource management or environmental pollution control. Because of the diverse nature of sources and the varying quality and availability of data, MFA results are inherently uncertain. Uncertainty analyses have received increasing attention in recent MFA studies, but systematic approaches for selection of appropriate uncertainty tools are missing. This article reviews existing literature related to handling of uncertainty in MFA studies and evaluates current practice of uncertainty analysis in MFA. Based on this, recommendations for consideration of uncertainty in MFA are provided. A five-step framework for uncertainty handling is outlined, reflecting aspects such as data quality and goal/scope of the MFA. We distinguish between descriptive (quantification of material turnover in a region) and exploratory MFA (identification of critical parameters and system behavior). Whereas mathematically simpler concepts focusing on data uncertainty characterization are appropriate for descriptive MFAs, statistical approaches enabling more-rigorous evaluation of uncertainty and model sensitivity are needed for exploratory MFAs. Irrespective of the level of sophistication, lack of information about MFA data poses a major challenge for meaningful uncertainty analysis. The step-wise framework suggested here provides a systematic way to consider available information and produce results as precise as the data warrant.

Aluminium (Al) consumption growth exceeded those of all other major metals over the last decades. The main driver for this development is the broad range of applications for Al and Al-alloys. As the growth in consumption went along with an increase of anthropogenic stocks and flows of Al, information about material cycles became a crucial issue in terms of resource management. In this study a comprehensive material flow analysis (MFA) of the flows and stocks of Al in Austria for the year 2010 is conducted. The focus of the presented Al balance is on data harmonization and plausibility checks, both based on extensive data and literature research. The stock of Al is derived from bottom-up calculations indicating a total stock of about 260 kg Al per capita with an annual growth of 11 ± 3.1 kg/cap yr in 2010. Total old Al scrap generation is calculated to be 7 ± 1 kg/cap yr. For considering data quality aspects of single input data an adopted method for uncertainty assessment has been applied to the different material flows. This allowed a consistent evaluation of uncertainties within the material flow model. Due to the substantial uncertainties associated with end-of-life Al flows and their significance for secondary Al production in Austria, a better data base is needed in order to evaluate and optimize national Al scrap utilization in secondary production. Therefore, a dynamic MFA model will be built for Austrian Al flows and, in conjunction with the results from the static analyses, will provide a reliable decision basis for future Al resource management.

This study provides a systematic approach for assessment of contaminants in materials for recycling. Paper recycling is used as an illustrative example. Three selected chemicals, bisphenol A (BPA), diethylhexyl phthalate (DEHP) and mineral oil hydrocarbons (MOHs), are evaluated within the paper cycle. The approach combines static material flow analysis (MFA) with dynamic material and substance flow modeling. The results indicate that phasing out of chemicals is the most effective measure for reducing chemical contamination. However, this scenario was also associated with a considerable lag phase (between approximately one and three decades) before the presence of chemicals in paper products could be considered insignificant. While improved decontamination may appear to be an effective way of minimizing chemicals in products, this may also result in lower production yields. Optimized waste material source-segregation and collection was the least effective strategy for reducing chemical contamination, if the overall recycling rates should be maintained at the current level (approximately 70% for Europe). The study provides a consistent approach for evaluating contaminant levels in material cycles. The results clearly indicate that mass-based recycling targets are not sufficient to ensure high quality material recycling.

Landfill mining has been proposed as an innovative strategy to mitigate environmental risks associated with landfills, to recover secondary raw materials and energy from the deposited waste, and to enable high-valued land uses at the site. The present study quantitatively assesses the importance of specific factors and conditions for the net contribution of landfill mining to global warming using a novel, set-based modeling approach and provides policy recommendations for facilitating the development of projects contributing to global warming mitigation. Building on life-cycle assessment, scenario modeling and sensitivity analysis methods are used to identify critical factors for the climate impact of landfill mining. The net contributions to global warming of the scenarios range from -1550 (saving) to 640 (burden) kg CO2e per Mg of excavated waste. Nearly 90% of the results' total variation can be explained by changes in four factors, namely the landfill gas management in the reference case (i.e., alternative to mining the landfill), the background energy system, the composition of the excavated waste, and the applied waste-to-energy technology. Based on the analyses, circumstances under which landfill mining should be prioritized or not are identified and sensitive parameters for the climate impact assessment of landfill mining are highlighted.

Material flow analysis (MFA) is a tool to quantify the flows and stocks of materials in arbitrarily complex systems. MFA has been widely applied to material systems in providing useful information regarding the patterns of resource use and the losses of materials entering the environment. MFA and life cycle assessment (LCA) are traditionally different tools for environmental decision support. The two methods are basically different with respect to the definition of system boundaries and the actual subject of investigation. However, there are also overlaps between the tools. These overlaps highlight that MFA and LCA can complement each other and thereby increase the quality of studies in both domains. Thus, the combination of these tools offers the potential for more consistent and reliable decision support in environmental and resource management.

Material Flow Analysis (MFA) studies for a particular substance often exist for several different countries or regions, but share a similar goal and scope. In direct comparisons of such regional resource budgets, the importance of the choices made in establishing an MFA system tends to be disregarded.We identify and quantify the effects of choices made in system layout, data material and uncertainty assessment on the outcome of regional MFAs using two recent country-scale MFAs (of Denmark and Austria) of phosphorus as a case study.We highlight the differences in system boundaries and definition of flows and processes. We quantify types and choice of data sources; analyse the consistency of the data used by looking at the extent of data reconciliation, as a measure of model quality; quantify the effect of different approaches to uncertainty assessment; and show the influence of aggregating/disaggregating flows.We show that differences in system layout are mostly attributable to varying goals and scope definitions. Direct comparison of uncertainties across studies is problematic: both studies draw on similar types of data sources, yet they show very different uncertainty assessments; the uncertainty assessment in MFA is always subjective to a certain extent. We demonstrate that reconciliation of conflicting data provides a useful measure to assess data consistency and model quality: data are more consistent (5% average change in reconciled data) in the Austrian than in the Danish (9%) case. We suggest an iterative approach to uncertainty assessment. Likewise, we demonstrate the effect of the aggregation of flows on model uncertainty.These findings quantify and emphasise the importance of examining MFA studies’ metadata and suggest an approach to be followed when drawing on such studies as a source of information.

Municipal solid waste (MSW) landfills need to be managed after closure to assure long-term environmental compatibility. Aftercare can be completed when the authorities consider the landfill not likely to pose a threat to humans and the environment. In this work, a methodology for deriving site-specific aftercare completion criteria is presented and its application is illustrated via a case study. The evaluation method combines models addressing waste emission behavior, long-term barrier performance, and pollutant migration to assess the potential impact of landfill emissions on the environment. Based on the definition of acceptable impact levels at certain points of compliance, scenario- and pollutant-specific aftercare completion criteria are derived. The methodology was applied to a closed MSW landfill in Austria and potential aftercare durations were determined. While landfill gas emissions may become environmentally tolerable within decades at the site, leachate-related aftercare measures were expected to be necessary for centuries (primarily as a result of ammonium). Although the evaluation comes with large uncertainties, it allows for linking aftercare intensity and duration with respect to an environmentally compatible state of the landfill in the absence of aftercare. However, further case studies including regulatory review and acceptance are needed to use the methodology in a decision support tool on aftercare completion.

After closure, municipal solid waste (MSW) landfills must be managed and controlled to avoid adverse effects on human health and the environment (HHE). Aftercare (or post-closure care) can be brought to an end when the authorities consider the landfill to no longer pose a threat to HHE. Different approaches have been suggested for long-term landfill management and evaluation of aftercare completion. In this paper, research on aftercare and its completion is analyzed and regulatory approaches for the completion of landfill aftercare are reviewed. Approaches to aftercare could be categorized as (i) target values, (ii) impact/risk assessment, and (iii) performance based. Comparison of these approaches illustrates that each has limitations and strengths. While target values are typically used as screening indicators to be complemented with site-specific assessments, impact/risk assessment approaches address the core issue about aftercare completion, but face large uncertainties and require a high level of expertise. A performance-based approach allows for the combination of target values and impact/risk assessments in a consistent evaluation framework with the aim of sequentially reducing aftercare intensity and, ultimately, leading to the completion of aftercare. At a regulatory level, simple qualitative criteria are typically used as the primary basis for defining completion of aftercare, most likely due to the complexity of developing rigorous evaluation methodologies. This paper argues that development of transparent and consistent regulatory procedures represents the basis for defining the desired state of a landfill at the end of aftercare and for reducing uncertainty about the intensity and duration of aftercare. In this context, recently presented technical guidelines and the ongoing debate with respect to their regulatory acceptance are a valuable step towards developing strategies for the cost-effective protection of HHE at closed MSW landfills. To assess the practicality of evaluation methodologies for aftercare, well-documented case studies including regulatory review and acceptance are needed.

Municipal solid waste (MSW) landfills are potential long-term sources of emissions. Hence, they need to be managed after closure until they do not pose a threat to humans or the environment. The case study on the Breitenau MSW landfill was performed to evaluate future emission levels for this site and to illustrate the effect of final cover installation with respect to long-term environmental risks. The methodology was based on a comprehensive assessment of the state of the landfill and included analysis of monitoring data, investigations of landfilled waste, and an evaluation of containment systems. A model to estimate future emission levels was established and site-specific predictions of leachate emissions were presented based on scenario analysis. The results are used to evaluate the future pollution potential of the landfill and to compare different aftercare concepts in view of long-term emissions. As some leachable substances became available for water flow during cover construction due to a change in the water flow pattern of the waste, a substantial increase in leachate concentrations could be observed at the site (e.g. concentrations of chloride increased from 200 to 800 mg/l and of ammonia–nitrogen from 140 to about 500 mg/l). A period of intensive flushing before the final cover installation could have reduced the amount of leachable substances within the landfill body and rapidly decreased the leachate concentrations to 11 mg Cl/l and 79 mg NH 4 –N/l within 50 years. Contrarily, the minimization of water infiltration is associated with leachate concentrations in a high range for centuries (above 400 mg Cl/l and 200 mg NH 4 –N/l) with low concomitant annual emission loads (below 12 kg/year of Cl or 9 kg/year of NH 4 –N, respectively). However, an expected gradual decrease of barrier efficiency over time would be associated with higher emission loads of 50 kg of chloride and 30 kg of ammonia–nitrogen at the maximum, but a faster decrease of leachate concentration levels.

Um einer Schadigung von Mensch und Umwelt vorzubeugen, bedurfen Deponien auch nach der Beendigung der Abfallablagerung einer Bewirtschaftung. Die notwendige Bewirtschaftungsintensitat ist je nach Abfallinventar und Emissionen, technischen Barrieren, sowie Umgebungssituation unterschiedlich. Die Modellierung von Emissionen abgelagerter Abfalle ist demnach ein wesentliches Element der Abschatzung von Deponienachsorgedauern. Vor diesem Hintergrund wird in dieser Arbeit das Emissionsverhalten von Hausmulldeponien, Schlackedeponien und Baurestmassendeponien beschrieben und bezuglich der Umweltvertraglichkeit diskutiert. Problematische Parameter unterscheiden sich je nach Deponietyp; generell von Bedeutung sind jedoch organischer Kohlenstoff, Stickstoff (v.a. Ammonium) und leicht losliche Salze im Sickerwasser. Schwermetalle stellen nur vereinzelt ein Problem fur die Einleitung des Sickerwassers dar. Aufbauend auf der Beschreibung des Emissionsverlaufes und des aktuellen Deponiezustands warden Ansatze zur Ermittlung zukunftiger Stofffreisetzungspotentiale aus dem abgelagerten Abfall vorgestellt. Diese Abschatzungen bilden gemeinsam mit der Beurteilung der Langzeitwirkung technischer Barrieren und der Empfindlichkeit betroffener Umweltsysteme die Basis zur Bewertung der Umweltvertraglichkeit von geschlossenen Deponien.

Municipal solid waste (MSW) landfills pose a long-lasting risk for humans and the environment. While landfill emissions under regular operating conditions are well investigated, landfill behaviour and associated emissions in case of flooding are widely unknown, although damages have been documented. This paper aims at developing a methodology for determining the proportion of MSW landfills endangered by flooding, and at evaluating the impact flooded landfills might have on the environment during a flood event. The risk of flooding of MSW landfills is assessed by using information about flood risk zones. Out of 1064 landfills investigated in Austria, 312 sites or about 30% are located in or next to areas flooded on average once in 200 years. Around 5% of these landfills are equipped with flood protection facilities. Material inventories of 147 landfill sites endangered by flooding are established, and potential emissions during a flood event are estimated by assuming the worst case of complete landfill leaching and erosion. The environmental relevance of emissions during flooding is discussed on the basis of a case study in the western part of Austria. Although environmental hazards need to be assessed on a site- and event-specific basis, the results indicate that flooded MSW landfills represent in general small environmental risks for the period of flooding. The longer term consequences of flooding are discussed in a next paper.

Within a product system of a life-cycle assessment (LCA), solid waste landfills should be treated as processes, because they are considered to be a part of the technical system. Hence, their inputs and outputs should be included in the life-cycle inventory analysis and evaluated within the life-cycle impact assessment. The aim of this paper is to discuss the consideration of emissions from solid waste landfills within the LCA framework and to investigate the uncertainties in existing modelling approaches. Based on this analysis the main limitations are discussed and recommendations for incorporating long-term emissions from landfills in LCA are made. It is emphasized that the lack of consideration of spatial and temporal characteristics of long-term emissions turns out to be an important source of uncertainty when modelling the environmental impact of landfills. For toxicity categories in particular, the life-cycle impact assessment might be the dominant source of uncertainty. However, in order to understand the reliability of LCA results with respect to landfill emissions, quantitative uncertainty should be routinely included in LCA studies and sources of uncertainty need to be thoroughly discussed.

The treatment of cooling appliances in Austria is primarily influenced by two factors. On the one hand is their changing composition and on the other hand the ordinance on Waste Prevention, Collection and Treatment of Waste Electrical and Electronic Equipment (WEEE ordinance), which stipulates a minimum recycling rate of 75% for cooling appliances. This paper investigates whether this recycling rate leads to optimal treatment practices for cooling appliances with respect to resource conservation and environmental protection. Two different treatment technologies which achieve recycling rates between 50–60% and 80–90%, respectively, are compared both for cooling appliances containing Chlorofluorocarbons (CFCs) and for appliances containing Volatile Organic Compounds (VOC). Materials and energy balances are developed for each model. To evaluate resource consumption, expenditures as well as savings of energy and materials are incorporated via the Cumulative Energy Demand (CED). In order to analyse the environmental impact of the different practices, balances for CFC, CO2, HF, HCl and solid residues are established. The results show that the treatment type aiming for a maximum of materials recycling contributes more to resource conservation than the other treatment type. But for CFC appliances the former is associated with substantial CFC emissions, which turn out to be most relevant when treating these appliances. Generally, it is found that the optimum recycling rate is a function of the composition of the appliance and the technologies applied, both in recycling and in primary production. A high recycling rate per se does not automatically result in an optimal solution with regard to resource conservation and environmental protection.