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This doctoral research is located in the branch of sustainability sciences that has the realisation of sustainable development as its core subject of research. The most broadly accepted notion of sustainable development is that which evolves along the resolutions, declarations, and reports from international processes in the framework of the United Nations (UN). The consensual outputs from such processes feature global-generalised and context-free perspectives. However, implementation requires action at diverse and context-rich local levels as well. Moreover, while in such UN processes national states are the only contractual parties, it is increasingly recognised that other (‘nonstate’) actors are crucial to sustainability. The research presented here places the attention on bottom-up initiatives that are advancing innovative ways to tackle universal access to clean energy and to strengthen small-scale family farmers. This means, the focus is on bottom-up initiatives advancing local implementation of global sustainability targets, more precisely, targets that make part of the Sustainable Development Goals two and seven (SDG 2 and SDG7). The research asks how such bottom-up initiatives can contribute to the diffusion of sustainability innovations, thereby also contributing to social change. Three aims are derived out of that central question: • Analytical: To understand the role of bottom-up initiatives in the diffusion of sustainability innovations and in the thereby involved social changes. • Transformative: To contribute with my research to the actual diffusion of sustainability innovations. • Methodological: To outline a research approach that provides a solid conceptual and methodological framework for attaining the analytical and transformative aims. Conceptually, the research builds on theoretical insights from diverse strands of the broad field of sustainability transitions – mostly on conceptualisations from transition management, strategic niche management, and grassroots innovations – as well as on conceptual and methodological advances in transdisciplinary and in transformative research. The doctoral research comprises four single studies, in which the notion of diffusion is explored at different scopes of social scales. It begins with a thorough analysis of diffusion programs of domestic biodigesters to rural households in countries of the global south. The focus is on the process by which this specific technical inno0vation results integrated (or not) into the daily realities of single rural households, that is, the adoption process. In the second study, the attention is on energy supply models based on different decentralised renewable technologies. Central to these models is the building of new (or strengthening of existing) local socioeconomic structures that can assume and ensure the proper operation and supply of energy services. The interest in this study is on the strategies that organisations implementing community-based energy projects apply to support the realisation of such local structures. The third study focuses on a network of bottom-up initiatives that have been advancing alternative approaches to family farming in Colombia. The network mainly comprises farmers associations, other organisations from civil society, and researchers who had been collaborating and experimenting with innovations in different innovation fields such as technical, organisational, financial, and commercialisation schemes. The aim of this third study is to provide insights into the challenges and difficulties faced by these actors in broadening the diffusion of the innovations they have been advancing. To perform this study, a methodological strategy is applied that combines a transdisciplinary mutual learning format with qualitative content analysis techniques. The fourth and last study is a conceptual disquisition. It develops a conceptual framework that (a) provides better accounts for the particularities of endeavours aimed at the diffusion of knowledge and practices from the bottom-up across local contexts and social scales, and (b) advances first conceptual steps towards an explicit account for the role that innovation research (and innovation researchers) can assume for the actual realisation of diffusion. The main findings or contributions of the doctoral research can be categorised into four subjects: 1) Bottom-up initiatives contribute to the diffusion of sustainable innovations by: (a) mobilising transformative resources for inducing diffusion in their scope of action; both their own as well as others’ resources; and (b) creating spaces for experimentation in which interventions can be tested (and if necessary adjusted) in order to ensure the proper deployment of innovations. 2) In their efforts to advance the diffusion of sustainability innovations, bottom-up initiatives contribute to social changes for (a) ensuring the effective deployment of the innovations, for instance: • by supporting change in the sociotechnical configurations that enable and constrain the daily practices of single households, in a way that permits the innovation’s proper operation; and • by reshaping local socioeconomic structures in order to ensure and sustain the supply of services and goods linked to the implemented innovation; (b) building local available storage of transformative resources, that is, the consolidation of local organisational structures that facilitate the building and binding of knowledge, financial capital, people’s skills, access to networks among other resources. Moreover, knowledge and practices from the bottom-up can transit to other social scales, and in this way contribute to social changes beyond their localities. 3) A conceptualisation of innovation diffusion, in which the work of academic researchers studying innovation is a constitutive part of transdisciplinary knowledge articulations that promote diffusion. In this way transdisciplinary research alliances can be envisioned in which researchers investigate about, with, and for bottom-up initiatives. 4) Contributions to the consolidation, systematisation, and dissemination of strategies that are applied by farmers associations in order to strength the economic, social, environmental, and cultural dimensions of Colombian family farmers. The contours of two research horizons for further research are outlined, they can be briefly described as: (a) explorations of diffusion beyond bottom-up localities involving changes of socio-political structures and (b) the development of conceptual and methodological frameworks for the realisation of bottom-up transformative research alliances.

This doctoral thesis examines how Sustainability-Oriented Innovations (SOIs) are emerging at small and medium-sized enterprises (SMEs) and how they can be managed. SOIs in the form of new products that lessen negative environmental impact, or even create a positive impact can play an important role, particularly at established SMEs who see business opportunities in sustainable development and consider a possible diversification into new sustainability markets. Whereas the extant literature discusses what SOIs are and why firms develop them, little is known about how they are developed. To enable firms to innovate for sustainability, it is essential to know more about the processes underlying SOI development, which are considered as very difficult, with many firms failing. Drawing on several academic papers and relying on qualitative research methods, the thesis uses the Fireworks model to examine how innovation processes unfold at established SMEs. The main contribution of the thesis is to advance the Fireworks model to the context of SOIs unfolding at SMEs. The findings reveal that SOIs unfold in an emergent, somewhat chaotic way, that duration and outcome are uncertain, that the overall journey is composed of multiple intertwined innovation paths, of which several will likely lead to setbacks. To manage this complex process, the thesis suggests to set four management foci: first, to create a dedicated organizational unit for exploration, second to create conditions allowing intelligent learning for efficient exploration, third to carry out in-depth investigation of the related technological innovation systems, and fourth to plan carefully the re-integration of the innovation into the core business for commercialization. This research contributes to the SOI literature by advancing the Fireworks model and thereby proposing a meta-model of how SOIs may dynamically unfold. Being both holistic and detailed, the model opens several avenues for future research. Finally, the research contributes to management practice by providing a heuristic to manage SOI development at SMEs.

The energy sector is regarded as one of the decisive subsystems influencing the future of sustainable development. Consequently, there is a need for a comprehensive transformation of energy generation, conversion and use. The importance of building capacities for energy policy development in developing countries is bound up with the need to formulate global strategies to meet the challenges that humanity face, especially to achieve the targets manifested in the Agenda 2030 and Paris Agreement. The aim of this research is to better understand how to empower marginalised key societal actors, co-produce alternative discourses about energy futures and articulate those discourses to influence policy change within a context of illiberal democracies in Latin America. The research concerns the design, function and effectiveness of scientifically grounded participatory process, which has been justified theoretically and tested empirically. The process presupposes theoretical perspectives relating to theory, method and empirical application. The first draws on theories of sustainability transition and transformation, including transition management. The second draws on ideas taken from the knowledge co-production and transdisciplinary sustainability research. The empirical application, concerns the implementation of a Transdisciplinary Transition Management Arena (TTMA) and its effectiveness, measured by potential for the co-production of knowledge and for stimulating collective action. As result of the process, a conceptual model of the energy system, long-term visions and transformation strategies were developed. The TTMA processes demonstrated that cross-sectoral and inter-institutional, combined efforts, can help actors visualize possible, future alternatives for sustainable energy development and how to realize such alternatives. The structures provided were helpful for the emergence and empowerment of new sustainable-energy-transition coalitions in both Ecuador and Peru. Chapter 1 describes the general context in which this scientific project is developed and presents a synthesis of the processes and its main outcomes. The research results are described in detail in the scientific papers presented in chapters 2,3 and 4.

This dissertation examines how smallholder farming livelihoods may be more effectively leveraged to address food security. It is based on empirical research in three woredas (districts) in the Jimma Zone of southwestern Ethiopia. Findings in the chapters that follow draw on quantitative and qualitative data. In this research, I focus on local actors to investigate how they can be better supported in their roles as agents who have the ability to improve their livelihoods and achieve food security. This general aim is operationalized through three research questions that are addressed in separate chapters. The research questions are: (i) How do livelihood strategies influence food security?; (ii) What livelihood challenges are common and how do households cope with these?; and (iii) How do social institutions, in which livelihoods are embedded, influence people’s abilities to undertake livelihoods and be food secure? Using quantitative data from a survey of randomly selected households, I applied a number of multivariate statistical analysis to determine types of livelihood strategies and to establish how these strategies are associated with capital assets and food security. Here I view livelihood strategies as a portfolio of livelihood activities that households undertake to make a living. The predominant livelihood in the study area was diversified smallholder farming involving mainly the production of crops. Food crops such as maize, teff, sorghum, and in smaller quantities – barley and wheat, were primarily produced for subsistence. Cash crops namely coffee and khat were primarily produced for the market. Based on our analyses, we found five types of livelihood strategies to be present along a gradient of crop diversity. Food security generally decreased with less crops being part of the livelihood strategy. The livelihood strategies were associated with households’ capital assets. For example, the livelihood strategy with the most number of crops had more access to a wider range of capital assets. They had larger aggregate farm field size, and were more involved in learning with other farmers through informal exchange of information and knowledge. The status of food (in)security of each household during the lean season was measured using the Household Food Insecurity Access Scale (HFIAS). A generalized linear model established that the type of livelihood strategy a household undertook significantly influenced their food security. Other significant variables were educational attainment and gender of household head. The findings contribute evidence to the benefits of diversified livelihoods for food security, in this case, the combination of diverse food crops and cash crops. Smallholder farming in southwest Ethiopia is beset with process-related and outcome-related challenges. Here, a process-related challenge pertains to the lack of different types of capital assets that people need to be able to undertake their livelihoods, while an outcome-related challenge pertains to lack of food. The most frequently mentioned process-related challenges were associated with the natural capital either as lack in necessary ecosystem services or high levels of ecosystem disservices. Farming households typically faced the combined challenges of decreasing soil fertility, land scarcity, die-off of oxen due to diseases, and wild animal pests that raided their crops and attacked their livestock. Lack of cash was also common and this was associated with an inability to access goods and services that households needed to address other problems. For example, lack of cash prevented households from buying fertilizers or replacing the oxen they lost to diseases. Confronted with multiple and simultaneous challenges, households coped by drawing on more readily accessible capital assets in order to address a lack. This process is here referred to as capital asset substitution. The findings indicate that when households liquidate a physical asset in order to gain cash which they then use to address other challenges, the common outcome is an erosion of their capital asset base. Many households reported having to sell their livestock to buy fertilizers, as required by the government, without seeing an increase in their harvest. The same process of liquidating capital asset to purchase food particularly during the lean season, also led to erosion of capital assets. On the other hand, when households drew on their social capital to address the challenges, they tended to maintain their capital asset base. The local didaro system is one such example in which farming households with adjacent farm fields synchronize their cropping timing and pool their labor together to address the problem of wild animal pests. Human capital, for example, in the form of available labor was also important for coping. Protecting and enhancing natural capital is needed to strengthen the basis of livelihoods in the study area, and maintaining social and human capitals is important to enable farming households to cope with challenges without eroding their capital asset base. Smallholder farming in southwest Ethiopia is embedded in a social context that creates differentiated challenges and opportunities amongst people. Gender is an axis of social differentiation on which many of the differences are based. Since the coming into power of the currently ruling Ethiopian political coalition, important policy reforms have been put in place to empower women. This includes the formal requirement that wives’ names are included in land certificates. Local residents reported notable changes related to gender in the last ten years. To make sense of the changes, we adapted the leverage points concept which identifies places to intervene in a system with different depths and effectiveness for changing the trajectory of a system. Using this concept, we classified the reported changes as belonging to the domains of visible gaps, social structures, and attitudes. Importantly, changes within these domains interacted, suggesting that changes facilitate further changes. The most prominent driver of the changes observed was the government’s emphasis on empowering women and government-organized interventions including gender sensitization trainings. The changes toward more egalitarian relationships at the household level were perceived by local residents to lead to better implementation of livelihoods, and better ability to be food secure. The study offers the insight that while changing deep, underlying drivers (e. g. attitudes) of systemic inequalities is critical, other leverage points such as formal institutional change and closing of certain visible gaps can facilitate deeper changes (e. g. attitudes) through interaction between different leverage points. This can inform gender transformative approaches. While positive gender-related changes have been observed, highly unequal gender norms still persist that lead to women as well as poor men being disadvantaged. Social norms which provide the basis for collective understanding of acceptable attitudes and behaviors are entrenched in people’s ways of being and doing and can therefore significantly lag behind formal institutional changes. For instance, daughters in southwest Ethiopia continued to be excluded from land inheritance because of long-standing patrilineal inheritance practices. This impacted on women’s abilities to engage in smallholder farming in equal footing as men. Norms influenced practices around access and control of capital assets, decision-making, and allocation of activities with important implications for who gets to participate, how, and who gets to benefit. Landless men also faced distinct disadvantages in sharecropping arrangements where people involved often have unequal socioeconomic status. Processes that facilitate critical local reflections are needed to begin to change unequal social norms and transform smallholder farming to becoming more inclusive and egalitarian spheres. To more effectively leverage smallholder farming for a food secure future, this dissertation closes with four key insights namely: (1) Diversified livelihoods combining food and cash crops result in better food security; (2) Enhancing natural and social capital is a requisite for viable smallholder farming; (3) Social and gender equality are strategically important in improving livelihoods and food security; and (4) Institutions particularly social norms are key to achieving gender and social equality. Because the livelihoods-food security nexus depend on people’s agency in their livelihoods, this dissertation concludes that livelihoods should be recast as critical spheres for expanding human agency and that conceptual development as well as formulation of suitable tools of measurement be pursued.

Polen weist insbesondere im Süden und Osten des Landes, aber auch in seinen anderen Landesteilen, eine kleinteilige Agrarstruktur auf. Eine solche kleinteilige Agrarstruktur ist in den Augen der polnischen Agrarpolitik ein unerwünschtes Phänomen. Entsprechend misst sie der Veränderung der kleinteiligen Agrarstruktur Polens zu größeren Einheiten hin eine hohe Priorität bei. Vor dem Hintergrund vielfältiger sozial-ökologischer Krisenphänomene, die oftmals mit einer intensiven, industriellen und großskaligen Landwirtschaft verbunden sind, stellt sich jedoch die Frage, ob solche Bestrebungen im Hinblick auf Nachhaltigkeit, der sich die polnische Agrarpolitik und die Politik für die Entwicklung ländlicher Räume ebenfalls verpflichtet, zielführend sind. Um dieser Frage nachzugehen, wurde für die vorliegende Dissertation in zwei landwirtschaftlich besonders kleinteilig strukturierten Regionen Polens (Wojewodschaft Lubelskie und Wojewodschaft Podkarpackie) eine empirische Studie unter Betreiberinnen und Betreibern von kleinen landwirtschaftlichen Betrieben durchgeführt. Ziel der Studie war es zu untersuchen, welche Lebenswirklichkeiten und Wirtschaftsweisen sich in kleinen landwirtschaftlichen Betrieben finden und ob diese Lebenswirklichkeiten und Wirtschaftsweisen den vielfältigen landwirtschaftsbezogenen sozial-ökologischen Krisenphänomenen entgegenwirken können. Den theoretischen Hintergrund der Arbeit bilden die Nachhaltigkeitsdebatte, das Konzept der gesellschaftlichen Naturverhältnisse der Sozialen Ökologie sowie wachstumskritische Positionen (insbesondere die Ansätze von Suffizienz und Subsistenz). Die Ergebnisse der empirischen Studie zeigen, dass die Lebenswirklichkeiten und Wirtschaftsweisen von Betreiberinnen und Betreibern von kleinen landwirtschaftlichen Betrieben sehr vielfältig sind. Die befragten Landwirtinnen und Landwirte verfolgen in ihren Betrieben unterschiedliche ökonomische Modelle - einige von ihnen sind ökonomisch erfolgreiche Landwirtinnen und Landwirte im Vollerwerb, andere haben sich bewusst für Nebenerwerbslandwirtschaft entschieden, und noch andere schließlich betreiben Landwirtschaft aus einer ökonomischen Notwendigkeit und einem Mangel an Alternativen heraus. Doch trotz der unterschiedlichen ökonomischen Modelle, die die befragten Landwirtinnen und Landwirten in ihren Betrieben verfolgen, liegen ihrem Handeln gleichermaßen der Wunsch nach Existenzsicherung und der Wunsch nach Autonomie als wesentliche Motivation zugrunde. Insgesamt zeigen die Ergebnisse der empirischen Studie einige der Herausforderungen für Betreiberinnen und Betreiber von kleinen landwirtschaftlichen Betrieben auf, die aus den gegenwärtigen institutionellen und politisch-wirtschaftlichen Rahmenbedingungen für die Landwirtschaft resultieren. Ebenso zeigen die Ergebnisse, dass die Wirtschaftsweisen, die in den untersuchten kleinen Betrieben vorgefunden wurden, nur bedingt zu einer nachhaltigen Entwicklung ländlicher Räume beitragen können. Die Ergebnisse der empirischen Studie zeigen insbesondere die Dringlichkeit auf, die gegenwärtigen politisch-wirtschaftlichen Rahmenbedingungen für die Landwirtschaft zu ändern und naturerhaltende Wirtschaftsweisen auch finanziell attraktiv zu machen, wenn diese einen Beitrag zu einer nachhaltigen Entwicklung ländlicher Räume leisten sollen.

The German energy system is under transformation. The so-called Energiewende (in English, Energy turn) relies, among other things, on renewable energies for building a more sustainable energy system. Regions (Landkreise) are one relevant level where different administrative bodies make decisions and plans both for the implementation and for the use of renewable energies. However, in order to realize the goals of the Energiewende, developments in the wider society are necessary. This is why, scientific research can and should foster such developments with more research on the social aspects of energy-related topics. The present work contributes to the understanding of transition processes towards a sustainable use of regional renewable energy by focusing on the role of contextual conditions, practical experiences, and temporal dynamics in the implementation and use of renewable energy in German regions. In this way, this work wants to contribute fostering the development of regional energy transition strategies for the realization of the Energiewende. The conceptual background for this piece of transformation research lies in three bodies of literature dealing respectively with transitions of socio-technical systems, transformations of socioecological systems, and time ecology. From a critical engagement with this literature, three main results have emerged. First, an evidence-based, spatially distinct analysis of contextual conditions for the use of renewable energy in all German regions has resulted in the identification of nine types of regions, so-called energy context types. Second, empirical research on practices in regional settings learned from the knowhow of actors from regional administration has shown that political and economic conditions are crucial as well as that process management, exchange, and learning are helpful for renewable energy implementation. Third, conceptual work about a deeper understanding of the temporal dimensions of transformation processes has made it possible to point out a three-step approach to include temporal dynamics into sustainability transformations management - the time-in-transformations-approach. The literature suggests that regions need to be treated individually; but developing an energy transition strategy for each region individually would be extremely resource intensive. Overall, my work outlines a compromise for a more efficient approach towards regional energy transition strategies which still considers the individuality of regions. As a result, I suggest to develop generic regional energy transition strategies that are adapted to each of the nine energy context types of German regions, that include the experiences of practitioners, and that consider temporal dynamics of transformation processes. Transdisciplinary research is a promising approach to meet many of the challenges for the realization of the Energiewende. A transdisciplinary steering board on the national level could create generic regional energy transition strategies that guide the energy transition and give clear goals and orientation for the realization of policies on the lower levels. On the regional level, these strategies would need to be adapted with regard to each region´s situation. Relying on the results of my research, I conclude that this could also be informed through transdisciplinary processes.

Die Arbeit liefert die Grundlagen zur chemischen Entfernung von Biodiesel aus dem Motoröl, um eine Minderung der Einschleppungsproblematiken beim Einsatz von biogenen Kraftstoffen und Dieselpartikelfiltern zu erzielen. Das Prinzip beruht auf einer wechselwirkenden Beimischkomponenten die eine Azeotropbildung mit Biodiesel einleitet. Eine gaschromatographische Headspace-Screening-Methode diente der Messung von Aktivitätskoeffizienten in Anwesenheit von Biodiesel. Die Ergebnisse dieser Analysen lieferten erste Erkenntnisse welche funktionalen Gruppen eine notwendige starke Wechselwirkung mit Biodiesel besitzen. Die gaschromatographischen Analysen wurden zudem mit Simulationsrechnungen mittels COSMOtherm untermauert. Im Laborversuch haben sich polare Säuren wie Ameisensäure oder Essigsäure als gute Beimischkomponenten erwiesen. Aldehyde, Ketone oder Alkohole sind weniger geeignet. Säuren wirken als Hydrogen Bond Donator und besitzen hohe Aktivitätskoeffizienten mit Biodiesel. Durch die Destillation des gebildeten azeotropen Gemischs kann die Entfernung von Biodiesel aus dem Motoröl bei niedrigen Temperaturen von ca. 180 Grad Celsius bis 190 Grad Celsius realisiert werden. Ohne den Einsatz von Beimischkomponenten liegt die Destillationstemperatur von Biodiesel bei ca. 330 Grad Celsius.

In der vorliegenden Arbeit geht es um eine Bildpraxis, die an die Fotografie gekoppelt ist. Die Forschungsarbeit von Vera Brandner baut auf der These auf, dass die Fotografie aufgrund ihrer ´Undiszipliniertheit´ speziell in inter- und transdisziplinären sowie interkulturellen Forschungsfeldern dem gemeinsamen Lernen und Forschen dienen kann, da sie für viele Menschen - egal woher sie kommen, welchen lebensweltlichen oder disziplinären Hintergrund sie mitbringen - leicht zugänglich und nutzbar ist. Auf diesen Zusammenhang beruht der methodologische Rahmen Generative Bildarbeit, den Vera Brandner in ihrer Doktorarbeit konzipiert, empirisch erprobt und konsolidiert hat. Verschiedene Aspekte fotografisch-visueller Methoden werden mit postkolonialer, fotokritischer und emanzipatorischer Theorienbildung verschränkt. Konzeptuelle und praktische Basisarbeit für die Entwicklung Generativer Bildarbeit wurde in der Arbeit des Vereins ipsum1 zwischen 2003 und 2010 in Angola, Pakistan, Afghanistan, Israel, Palästina und Österreich geleistet. Es handelt sich dabei um eine Systematisierung der verschiedenen Blickakte, Interaktions- und Reflexionsformen, die im fotografischen Geflecht möglich sind, um diese für das dialogische Arbeiten mit Menschen verschiedener Erkenntniskulturen nutzbar zu machen. Die Fotografie wird als Praxisform in Situationen eingesetzt, in denen die beteiligten Akteur_innen einander aufgrund ihrer unterschiedlichen Herkunft, Sozialisierung und Spezialisierung fremd sind, durch geteilte Problemstellungen jedoch miteinander in Verbindung stehen. Es geht bei Generativer Bildarbeit um ein Arbeiten an den Grenzen des Eigenen und des Anderen, wobei diese Problemstellungen zugänglich, beforschbar und transformierbar gemacht werden. Die Fotografie wird zum Übungs- und Forschungsfeld für das Umgehen mit Kultureller Differenz. In diesem Übungsfeld entwickeln die Teilnehmer_innen Gestaltungs- und Reflexionsformen, um mit bestehenden Widersprüchen und Unsicherheiten ihrem jeweiligen Kontext entsprechend umzugehen.

The dissertation project focuses on empirically investigating consumers´ attitudes, motiva-tions and purchasing decisions regarding sustainable products. The focus on this micro per-spective, however, does not reflect consumers´ roles within the transformation towards sus-tainable consumption. Therefore, the present framework paper puts the included papers into a greater context and evaluates the findings on a meta-level by applying an enhanced transition management theory. The analysis underlines that consumers´ limited personal capabilities are an underlying reason for unsustainable practices. Therefore, the active engagement not only of consumers, but also of companies is required if the transformation is to be successful. If companies actively support consumers in making sustainable choices, consumers can engage in sustainable consumption with only low cognitive efforts. On this basis, genuine sustainable choices are enabled. The dissertation provides practical implications by highlighting potential measures which will help to promote sustainable products from niches to mainstream. In sum, the dissertation project enhances academic understanding of consumers´ sustainable purchas-ing behavior and reveals the potential of integrating such insights into the management of transformations towards sustainable consumption.

In der Wasser- und Abwasseruntersuchung hat der Summenparameter eine heraus-ragende Bedeutung. Sowohl in der gesetzlichen Überwachung als auch der Bemes-sung von Abwasserbehandlungsanlagen werden Belastungen vielfach über die Zu-sammenfassung von Einzelstoffen in Stoffgruppen ausgedrückt. Stoffgruppen lassen sich mit Hilfe von Summenparametern zuverlässig und im Vergleich zu Einzelstoffen mit geringerem Aufwand bestimmen. Im Rahmen dieser Arbeit werden die Verfahrens-grundlagen der Summenparameter und ihre Verwendung in der Wasser- und Abwas-seruntersuchung erläutert. Ein bedeutender wie auch umstrittener Summenparameter ist der AOX - Adsorbier-bare organisch gebundene Halogene (AOX). Bedeutend ist er deshalb, weil er ein ord-nungs- und abgaberechtlich relevanter Abwasserparameter ist. Umstritten ist er unter anderem, weil er ursprünglich für andere Zwecke als die Abwasseruntersuchung ent-wickelt wurde. Seinerzeit war der AOX ein Überwachungsparameter für Trinkwasser. Als Abwasserparameter dient er zur Erfassung einer im Abwasser unerwünschten Stoffgruppe, der besorgnisauslösende Eigenschaften wie Persistenz, Bioakkumulier-barkeit und Toxizität (PBT-Eigenschaften) zugeschrieben wird. Im zweiten Teil der Ar-beit wurden exemplarisch am Parameter AOX die Zusammenhänge zwischen Stoff-parametern und besorgnisauslösenden Eigenschaften bzw. Wirkungen der ausge-wählten parameterausmachenden Substanzen untersucht. Die Untersuchungsergeb-nisse wurden vor allem in Zusammenhang mit der Ermittlung und Verankerung von Mindestanforderungen für das Einleiten von Abwasser bewertet.