Open Access

This cumulative dissertation investigates food policy councils (FPCs) as potential levers for sustainability transformation. The four research papers included here on this recent phenomenon in Germany present new insights regarding the process of FPCs’ emergence (Emergence paper), the legal conditions which affect their establishment (Legal paper), the different roles of FPCs in policy-making processes (Roles paper) and FPCs’ potential to democratise the food system (Food democracy paper). Drawing on and contextualizing the results of the four individual studies, the framework paper uses the leverage points concept originally developed by Meadows (1999) and adopted by Abson et al. (2016) as a lens to discuss FPCs’ potential as levers for sustainability transformation. This conceptual background includes three so-called realms of leverage, which are considered to be of particular importance in transformational, solution-oriented sustainability science: first, the change, stability and learning in institutions (re-structure), second, the interactions between people and nature (re-connect) and third, the ways in which knowledge is produced and used (re-think). Framing the findings of the four research papers in terms of these three realms, the framework paper shows that FPCs could serve as cross realm levers, i.e. as interventions that simultaneously address knowledge production, institutional reform and human-nature interactions.

This dissertation, entitled “How to Embed Sustainability in the Core of Higher Education Institutions: Drivers of, Barriers to, & Patterns behind the Implementation Processes of Sustainability Curricula – Insights from a Quantitative Meta-Study with Data from around the Globe,” addresses the question of how sustainability curricula1 can be implemented and established in higher education institutions2. This research question is based on the assumption that sustainable development requires new ways of thinking and acting in the world. Accordingly, universities – as hubs for knowledge generation, innovation, and education – provide a central leverage point for sustainably developing society at large. Therefore, the institutionalization of sustainability curricula is not only socially demanded, but also stipulated in numerous political statements from the international community (e.g., those of the UN and UNESCO) and operationalized via Sustainable Development Goal No. 4: “Quality Education”. Previous findings on how such implementation can be successful and what factors support or inhibit the process have come primarily through case studies of individual higher education institutions. These studies provide important insights but have been largely descriptive rather than analytical and leave open questions about the generalizability of their findings – for example, the extent to which other universities can be guided by the experiences of the respective higher education institutions. The present dissertation addresses this research gap. Through a meta-study (i.e., an analytical comparison of existing case studies), generalizable findings on the implementation processes of sustainability curricula are explored. In the first step, a case universe was collected in order to provide a database for deeper analyses. In two further analysis steps that built on the case universe from Step 1, certain factors that promote or inhibit the implementation of sustainability curricula (Step 2) and specific implementation patterns (Step 3) were examined. The following paragraphs provide greater details and an overview of the respective findings. In the first step, a database of peer-reviewed English-language case studies from around the globe that report on such processes was created. A total of 230 case studies were identified, 133 of which focus on the implementation processes of sustainability curricula.3 A bibliometric analysis of the 230 case studies revealed that this field of research is growing, although the discourse is primarily dominated by authors from North America, Europe, Oceania, and Asia, with South America and Africa being underrepresented. In addition, a citation analysis demonstrated that some universities incorporate findings from other countries whereas other universities act in isolation. This observation leaves open the question of the extent to which universities learn from one another in order to advance the implementation of sustainability curricula. In the second step of the analysis, the qualitative data of the collected case studies (sample of 133 case studies) were compared using the case survey method, which is a specific type of a meta-1 Sustainability curricula include courses, programs, and certificates from all fields of study that deal in some form with sustainability topics. For a more-detailed discussion of what education for sustainable development (ESD) entails, see Section Error! Reference source not found.. 2 Higher education institutions (HEIs) include universities, universities of applied sciences, and other institutions that offer at least a bachelor’s degree. 3 A detailed explanation of the case sample and subsamples can be found in Section Error! Reference source not found.. analysis. The focus of the comparison lay on the drivers of and barriers to the processes of sustainability curriculum implementation at higher education institutions. Driving- and inhibiting factors have been thoroughly examined theoretically in the discourse on education for sustainable development (ESD), especially those pertaining to higher education institutions. However, no large body of data has yet been created to empirically test these hypotheses. The present meta-study found that the following factors lead to the deep-rooted and comprehensive establishment of sustainability curricula: strong leadership support; the establishment of sustainability curricula in the areas of education, research, campus operations, and outreach activities; formal participation of internal (including students) and external stakeholders; and engagement by sustainability champions (change agents), who are often the first to implement sustainability curricula and can face strong resistance. Other enabling factors include strategic planning, coordination, communication, having a vision, external political influence, the presence of a window of opportunity (e.g., an environmental disaster, a change in presidency), and the availability of interdisciplinary meeting spaces. On the other hand, the strongest cited barriers to the implantation of sustainability curricula were found to be the lack of interdisciplinary meeting spaces, the lack of a vision, the lack of incentives, the lack of resources, an overly full curriculum, and an unsupportive / overly bureaucratic organizational structure. The third step of the analysis also built on data from the 133 case studies and explored whether certain types or patterns of implementation processes occur. Through the analysis, six implementation patterns were identified that share similar driving- and inhibiting factors. The respective interplay between factors leads to various degrees of sustainability curriculum implementation in terms of how deeply rooted and comprehensive this implementation is. As discussed in greater detail below, in descending order of the level of achieved deep-rooted change, these patterns are (1) a collaborative paradigm shift, (2) bottom-up institutional change, (3) top-down institutional change, (4) the presence of many barriers that hinder institutional change, (5) externally driven initiatives, and (6) initiatives that are scattered due to a lack of coordination. Across all patterns, two phases could be identified: First, the impetus to implement ESD may be initiated not only by internal actors, but also by external ones. This initiation can take hold from the “bottom-up” (i.e., by students or faculty), from the “top-down” (i.e., at the presidential level), or in both directions simultaneously. The following key factors appear to be important in driving the initial implementation forward: a culture of open communication between all stakeholders in which feedback and reflection are welcome and even actively solicited, the development of a shared understanding and vision that further create a sense of ownership and long-term success, a high level of collaboration among all stakeholders, and existing initiatives that lead to knowledge sharing and other resources. In this regard, informal collaboration and cooperation can partially compensate for a lack of presidential-level support and/or a formal communication structure. Furthermore, developing a strategy with individual steps and shared responsibility leads to more-successful implementation of ESD at higher education institutions. The presented findings add a complementary empirical perspective to the discourse on the establishment of ESD at higher education institutions. First, the case studies that specifically address the implementation processes of sustainability curricula are reviewed and analyzed here for the first time as part of a research landscape. This research landscape reveals where research on such implementation processes has been or is being conducted. On this basis, both researchers and funders can reflect on the status quo and plan further research- or funding endeavors. Second, this dissertation offers the opportunity to compare a multitude of individual case studies and thus to develop new and generalizable insights into the implementation of sustainability curricula. The empirical analysis uses 133 case studies to identify key factors that promote or inhibit the implementation of sustainability curricula and to add a complementary perspective to the discourse, which has thus far been dominated by theoretical considerations and individual case studies. The analysis thereby offers a new perspective on generalizable influencing factors that appear to be important across different contexts. Thus far, specific patterns of implementation processes have been infrequently studied, and with few datasets. This dissertation analyzes the complex interplay between over 100 variables and provides one of the first research attempts at better understanding the processes that lead to the deep-rooted and comprehensive implementation of sustainability curricula. Internal and external practitioners of higher education institutions can find examples and evidence that can be useful in planning the next steps of their sustainability curriculum implementation. In the future, higher education institutions will play an even greater role in the journey toward sustainable development. This dissertation offers generalizable empirical findings on how universities can succeed in recognizing their own responsibility to that end and in realizing this transformation through the implementation of ESD.

„Einfachheit“ gehört zu den maßgeblichen Begriffen, mit denen in der Kunst-, Kultur- und Literaturgeschichte unterschiedliche Wertzuschreibungen einhergehen. Seit Ende des 20. Jahrhundert setzt sich nebenher ein globalisierter Lifestyle durch, der mit geschickten Werbetriggern eine „Sehnsucht nach Einfachheit“ weckt und hohe Erwartungen an das Ideal der Komplexitätsbewältigung knüpft. Das damit einhergehende breite Funktionalisierungspotential wird hier aufgegriffen, um den neuen Fragen nachzugehen, warum die Einfachheit einen bemerkenswerten Erfolg in der deutschsprachigen Gegenwartsliteratur feiert und was uns vergleichbare Bewegungen in Architektur, Design und den visuellen Künsten über den aktuellen Ruf nach Einfachheit erzählen. Am Beispiel des erzählerischen Werks von Judith Hermann, Peter Stamm und Robert Seethaler wird erstmalig gefragt, mit welcher Intention und Qualität sich die Einfachheit in den Texten dieser Autoren formiert und ob es sich bei der Kunst der erzählerischen Reduktion um ein spezifisch für die Gegenwart relevantes Konzept handelt. Die Studie leistet damit einen wesentlichen Beitrag zu der noch ausstehenden literaturwissenschaftlichen Systematisierung einer „Ästhetik der Einfachheit“.

This dissertation focused on the nature and role of organizational practices for the employment of older people and the extension of their working lives. The set of four articles is driven by the objective to further deepen our understanding of how organizations can facilitate ageing at work to the benefit of both, employees and employers. Findings are empirically based on qualitative expert interview data from Germany and the U.S. and several quantitative field studies among older employees in Germany. To bridge gaps in measurement of organizational practices related to aging at work, this dissertation proposes a new comprehensive, multifaceted, and thoroughly conceptualized measure of organizational practices related to aging at work, the Later Life Workplace Index (LLWI). Through the course of the four articles the LLWI is conceptually developed based on qualitative interview data, operationalized, validated based on multiple field studies among older workers, and applied in a multi-level study among older employees of 101 organizations. Results suggest that organizational practices are not uniform, but multifaceted in their presence within organizations and their effects for the employment of older workers. The LLWI distinguishes nine domains of practices including an age-friendly organizational climate, work design, individual development, and practices tailoring the retirement transition. Thus, it may lay the foundation for more granular organizational level research in the field. Further, this dissertation’s fourth article applies the LLWI and argues based on person-environment fit and socio-emotional selectivity theory that organizational practices address different individual needs and, thus, affect employment depending on employees’ individual characteristics. Results suggest that older employees’ retirement intentions are effected by individual development, transition-to-retirement, and continued employment practices depending on their health resources. Application of the new measure in practice to improve organizations’ response to the aging workforce and opportunities for future research based on the LLWI are discussed.

The global food system faces many complex challenges, and there is general agreement that a transformation is needed. While localizing food has been proposed as a means to this end, changing global food supply chains may also lead to sustainable food systems. Because most food systems today have an international dimension and are likely to remain connected, on one way or another, to other ones across the globe, it is necessary to find solutions to problems such as exploitation or environmental degradation. Current approaches such as Fairtrade certification often result, however, only in incremental change, and it is not clear how the current system could be transformed to make it sustainable. Addressing this challenge and the related gap in the literature, this study examines the emerging practices of small intermediary food businesses, which act between agricultural producers and consumers, and may have the potential to advance sustainability in international food supply. Including a systematic review of the literature on food systems change (Study#1), this dissertation adopts a transformational sustainability research methodology, which is solutionoriented, aims to integrate system, target and transformation knowledge, and is characterized by a transdisciplinary research practice. It conceptualizes challenges of international food supply and empirically investigates entrepreneurial solution approaches to address these challenges (Study#2). Two transdisciplinary research projects with small coffee businesses located in Germany, Mexico, and the U.S. were conducted to examine how these approaches could be implemented (Study#3, Study#4, Workshop reports 1+2). This study shows that challenges in international food supply chains can be conceptualized as negative effects of large geographical and relational distances. It also identifies five entrepreneurial solution approaches specified by twelve sustainability-oriented design principles to address these negative effects. Creating relational proximity between supply chain actors, that is, strong relationships based on knowledge and care, seems to be a key factor to advance sustainability in international food supply.The results also suggest that by building such strong relationships and changing the fundamental principles of international food trade (e.g. putting people before profits), small intermediary businesses could be important agents in food system transformations. The findings also highlight the importance of collaboration with peers in local networks, in which new sustainable business practices could be shared and disseminated. Transdisciplinary collaborations involving both researchers and small food businesses could result in innovative solutions and, ultimately, a transformation of food systems. Although the small-sized businesses examined here are already highly committed to sustainability, this study has important implications for researchers and practitioners, including individual entrepreneurs, who aim to advance sustainability in international food supply.

In this dissertation, advanced nonlinear control strategies and nonlinear minimum-variance observation are combined, in order to improve the estimation and/or tracking quality within control and fault detection tasks, for several types of systems from the fields of electromobility and conventional drivetrain technology that have some potential for sustainability or performance improvements. The application-specific innovations in terms of nonlinear Kalman filter methods are: * Improved state of charge estimation for Lithium-ion battery cells, powered by a novel self-adaptive EKF that uses a high-order polynomial curve fit as a decomposition of the uncertain nonlinear output equation with intentionally redundant bases, and with a reduced number of polynomial parameters that are adapted online by the EKF itself. * Online estimation of the time delay between two periodic signals of roughly the same shape that have pronounced uncorrelated noise, based on a fractional-order approximation of the transcendent transfer function of the time delay which is used as a model in a novel kind of EKF. * Using two (E)KFs (one for the linear subsystem and one for the nonlinear subsystem of a new kind of multi-stage piezo-hydraulic actuator) in a cascaded loop structure in order to reduce the computation load of the estimation, by appropriate 'interfacing' between the two observers (using one shared system model equation, among other aspects). The innovations in terms of nonlinear control methods are powered by observation, as well: * Sliding mode velocity control of a DC drive that is subject to nonlinear friction and unknown load torques, enhanced by an equivalent control law, and with a new intelligent switching gain adaptation scheme (for reduced control chattering and, thus, less energy consumption and actuator wear), which is powered by Taylor-linearized model predictive control, which in turn requires observer-based disturbance compensation (by a KF with a double-integrator disturbance model) for model-matching purposes in order to function correctly. * Direct speed control of permanent-magnet three-phase synchronous motors that have a high power-to-volume ratio, based on sliding mode control in a rotating d,q coordinate system, with a new equivalent control method that exploits both system inputs and with a secondary sliding surface to ensure compliance with the current-trajectory of maximum efficiency for the required torque, and which works without measurement of the rotor angle (thanks to a new kind of EKF that estimates all states in the stationary α,β coordinate system, as well as the disturbance/load torque and its derivative). In all instances, improvements (compared to methods existing in the literature) in terms of control and estimation performance have been achieved and confirmed using simulation studies or real experiments.

Water is vital for humankind and ecosystems alike. However, population growth, agricultural inten-sification, urbanization, and climate change embody potential hazards and pressures for water re-sources without existing long-term solutions. For two decades now, policy and governance literature has increasingly emphasised the role of learning in finding solutions to environmental policy prob-lems and effectively steering governance practices. Participation of non-state actors in decision mak-ing is widely considered to deliver learning products that support effective outcomes for environ-mental problems. Besides, the institutionalisation of participation through legislation opens up the necessity for (administrative) organizers to learn about participation as a governance mode in order to steer its effective working. Apart from participation, management approaches specifically aiming at driving learning, such as adaptive management (AM), are increasingly endorsed in water govern-ance. Despite the current prominence of learning in the environmental governance literature, evi-dence is lacking on which learning approaches function effectively regarding outcomes, whether participation aids learning, and how learning about successful governance arrangements is most effectively promoted. This doctoral dissertation aims to contribute to clarification of the potential of learning for water governance. The goal is to trace and understand the environmental impacts of learning through par-ticipation (research aim 1) and adaptive management (research aim 2), and the effect of learning on participation as a governance mode (research aim 3). For this goal, I engage in a predominantly qualitative research design following the case study method. For every specific research aim cases are selected and analysed qualitatively according to conceptual categories and mechanisms which are defined beforehand. Quantitative studies are used to corroborate the results for research aim 1 and 2 in a mixed-method approach to enhance the valid-ity of results. The empirical research context is European water governance, the implementation of the EU Water Framework and EU Floods Directive (WFD, FD) specifically. Eight cases of participa-tory decision-making across three European countries and five cases of AM in Northern Germany for WFD implementation are examined to identify whether learning in these processes enhanced envi-ronmental outcomes. To detect whether governance learning by public officials occurred, the design of participatory processes for FD implementation in ten German federal states is assessed. The findings of research aim 1, understanding learning through participation and its effects on water governance, reveal that participatory planning led to learning through improved understandings at an individual and group level. Learning did, however, hardly shape effective outcomes. In the AM cases (research aim 2) managers and participants of implementing networks improved their knowledge as well as capacities, and spread the results. Nonetheless, environmental improvement was not necessarily linked to ecological learning. Regarding learning about participation as a govern-ance mode (research aim 3) all interviewed public officials in German federal states reported some degree of governance learning, which emerged not systematically but primarily drawing on own experiences and intuition. These findings are condensed into three overarching lessons for learning in water governance: (1) Interactive communication seems to form the overall frame for participant and group learning. Framing of learning experiences turned out to play an important and potentially distorting role, for which professional facilitation and structured knowledge aggregation methods might be an im-portant counterbalance. (2) Learning did not automatically enhance environmental outcomes. It may thus not be an explanatory variable for policy outcomes, but a conditioning or intervening vari-able related to collective action, motivation for participation, and situating the issue at hand at wider societal levels. (3) The concepts of puzzling and powering might help understand learning as a source for effectiveness in the long-term when complemented with interest-based debates for creat-ing sufficient political agency of policy issues. Learning seen as puzzling processes might instruct acceptance and legitimization for new powering efforts. The perpetuation of learning in systematic ways and structures appears to characterize an alternative to this reflexive and strategic interplay, for which the water-related EU directives provide the basis. These insights are of practical and policy relevance, particularly for policy makers and practitioners in the pursuit of learning. They may further contribute to the academic understanding of learning in water governance and its potential contribution to transforming and adapting water governance re-gimes, as envisioned in the European water-related directives.

Das Bildungskonzept Bildung für nachhaltige Entwicklung (BNE) gilt als Schlüsselfaktor für eine nachhaltige Entwicklung. Durch die Entwicklung von Schlüsselkompetenzen sollen Menschen dazu befähigt werden, aktiv an der Gestaltung von Gegenwart und Zukunft im Sinne einer nachhaltigen Entwicklung zu partizipieren. Die Stärkung der Kompetenzen von Multiplikatorinnen und Multiplikatoren und somit Lehrkräften als Gestalterinnen und Gestalter formaler Bildung ist ein Ziel auf dem Weg zu einer inklusiven, qualitativ hochwertigen Bildung für alle und zur Befähigung aller, eine nachhaltige Entwicklung zu unterstützen. Es gilt, im Verlauf der Lehrkräftebildung Möglichkeiten zu schaffen, die Entwicklung relevanter Kompetenzen gezielt zu unterstützen, um effektivere Ergebnisse im Bereich BNE zu erreichen. Für den universitären Teil der Lehrkräftebildung geht dies einher mit einer entsprechenden Gestaltung von Lernumgebungen, durch die angehende Lehrkräfte relevante Kompetenzen zu Beginn ihres individuellen Bildungsweges entwickeln können. Darüber hinaus sollen durch entsprechende Fort- und Weiterbildungsformate auch bereits im Schuldienst tätige Lehrkräfte erreicht werden. Das als transdisziplinäres Format angelegte Entwicklungsteam Sachunterricht, bestehend aus Sachunterrichtslehrkräften, Vertreterinnen und Vertretern außerschulischer Bildungsorte und Forschenden der Universität, bildet den Ausgangspunkt dieser Arbeit. Die vorliegende Arbeit fokussiert die Untersuchung von Möglichkeiten der Professionalisierung von (angehenden) Lehrkräften zu BNE im Kontext des Entwicklungsteams. Dazu wurde zunächst theoretisch-konzeptionell der Frage nachgegangen, welche Kompetenzen relevant für die Integration von BNE in Schule und Unterricht sind und wie Lehr-Lernsettings gestaltet werden sollten, um die Entwicklung entsprechender Kompetenzen zu unterstützen. Im Rahmen zweier empirischer Studien wurde anschließend einerseits die Kompetenzentwicklung seitens der Studierenden analysiert, die an einem durch das Entwicklungsteam begleiteten Seminar teilnahmen. Andererseits liegt der Fokus auf dem spezifischen Format des transdisziplinären Entwicklungsteams und es wurde untersucht, inwiefern wechselseitiges Lernen zwischen den Entwicklungsteammitgliedern initiiert werden und dies in einer Veränderung der pädagogischen Praxis resultieren kann. Aufgrund seiner hohen Anschlussfähigkeit an den bildungswissenschaftlichen Diskurs wurde das Modell der BNE-spezifischen professionellen Handlungskompetenz den konzeptionellen Überlegungen und den darauf aufbauenden empirischen Untersuchungen zugrunde gelegt. Die Gestaltung eines Lehr-Lern-Settings für angehende Lehrkräfte mit dem Ziel der Förderung entsprechender Kompetenzen wurde anhand des Konzepts der offenen Lernumgebung vorgenommen. Die Ergebnisse zeigen zum einen, dass das in enger Zusammenarbeit mit dem Entwicklungsteam als offene Lernumgebung durchgeführte Seminar die Professionalisierung der Studierenden unterstützt und der Aufbau von (BNE-spezifischer) professioneller Handlungskompetenz durch kollaboratives Gestalten in Kooperation mit der Praxis ermöglicht wird. Zum anderen zeigt sich, dass die transdisziplinäre Zusammenarbeit ein wechselseitiges von- und miteinander Lernen zu BNE im Entwicklungsteam Sachunterricht fördert und Professionalisierungsprozesse sowohl seitens der Lehrkräfte als auch des außerschulischen Akteurs zumindest in einigen Bereichen angestoßen wurden. Ein zusätzliches Diffusionspotential für den Praxistransfer von BNE konnte in Hinblick auf das im Seminar entwickelte und an den Schulen integrierte Unterrichtsmaterial identifiziert werden. Zudem konnten im Verlauf des Seminars wechselseitige Lernprozesse zwischen Studierenden und Entwicklungsteammitgliedern initiiert werden, was die Möglichkeit eines weiteren, bisher weitestgehend unbeachteten Transfers von Innovationen wie BNE in die schulische Praxis birgt.

In response to the globally increasing environmental, social, and economic crises, we as humanity must leave the path of business as usual and learn new ways to know, think, and act which may enable us to build a more sustainable future for all. In their role as facilitators, teachers in general are considered one, if not the most important, factor for successful learning. The implementation of education for sustainable development (ESD) across all education systems and preparing students to act as future change agents and lead the societal transformation towards sustainability also largely depends on competent and committed teachers. Correspondingly, the focus of political agendas and scientific research increasingly shifts to the effective education of educators. The different competence models that are currently being discussed in the international discourse around teacher education for sustainable development (TESD) suggest various sets of intended learning outcomes (ILOs). Yet, they usually share the assumption that teachers require ESD-related knowledge, pedagogical skills, and motivation to successfully implement ESD at the school level. In accordance with the concept of ESD-specific professional action competence (Bertschy et al., 2013), educational offers in ESD for pre-service teachers should also develop their content knowledge (CK), pedagogical content knowledge (PCK) as well as a positive attitude towards ESD. However, in the sense of a comprehensive construct, this concept has not yet been operationalized or measured. Furthermore, there is still a lack of deeper understanding as to how to best design individual courses as teaching and learning environments in TESD in order to support competence development in student teachers. Based on a dual case study, this cumulative dissertation investigates how individual ESD courses, as part of the teacher education programs at Leuphana University in Lüneburg/ Germany and Arizona State University (ASU) in Tempe/USA, actually foster students’ ESD-specific professional action competence. Furthermore, this work sheds light on the link between learning processes and outcomes, to reveal which factors actually affect the achievement of ILOs and competence development. The findings of this study indicate that both courses under investigation eventually live up to their role and increased student teachers’ competence and commitment to implement ESD in their future careers; yet, mainly due to their different thematic foci, to varying degrees. Additionally, the four Cs (personal, professional, social, and structural connections) were revealed as significant factors that support students’ learning and should be considered when planning and designing course offerings in TESD, with the goal of developing students’ knowledge, skills, and attitudes.

The presence of pharmaceutical drugs and their by-products as environmental organic contaminants in a variety of eco-systems and their potential environmental impacts is a well-known aspect and has been raised in recent years. Studying the transformation of pharmaceutical drugs in the aquatic system is very important as it can lead to the formation of many new transformation products (TPs) that can have different properties (e.g. more mobile, toxic or present at higher concentrations) and this can enable them to reach the environmental compartments not affected by their parent compounds. Yet, many of the pharmaceutical drugs are not well regulated or controlled and they can cause a lot of adverse ecological and/or human health effects. In addition, impact of the continuous change in the environmental conditions such as pH, temperature and initial concentration on the transformation behaviour of pharmaceuticals is overlooked in many researches although it is of high interest. Psychotropic drugs are among the pharmaceuticals which their potential hazards including environmental fate and behaviour is still not well understood compared to other drugs such as antibiotics. Psychotropic drugs are highly used, and their worldwide consumption has been increasing nowadays especially in developed countries such as Europe and the United States. Furthermore, they are highly found in different environmental compartments and can cause a lot of toxicological problems. Trimipramine (TMP), Desipramine (DMI) and Chlorprothixene (CPTX) are three psychotropic drugs with closely related chemical structures and they are selected to be studied in this thesis as they are among the worldwide commonly prescribed psychotropic drugs and data available on their environmental fate (e.g., degradation or transformation and fate of the TPs) is lacking in the environmental researches. To investigate the ecological impact of the pharmaceuticals on water organisms and to study their fate in the aquatic system, laboratory biodegradation and photodegradation tests are recommended. The use of LC-MS/MS analysis with the combination of photolysis and biodegradation tests to identify the formed TPs and to study the biodegradability and the persistence of the TPs is a helpful new insight into the environmental behaviour of contaminants and their TPs. Different environmental conditions can affect the fate of pharmaceuticals in the environment, therefore answering the question how different variables such as temperature, pH and initial concentration could affect the degradation pattern of pharmaceuticals can provide valuable information regarding their environmental fate. Toxicity assessments of contaminants and their TPs using in-silico software based on quantitative structure activity relationship (QSAR) models can be a good choice especially in case of TPs because the TPs are mostly not available commercially and II are usually only formed in low concentrations within complex matrices so that isolation and purification are very difficult. Accordingly, the principle of this thesis was to study the environmental fate of three highly used psychotropic drugs and this achieved through: 1) examining the biodegradability of TMI, DMI and CPTX, 2) studying the behaviour of TMP, DMI and CPTX in photodegradation tests using Xe and UV lamps with studying the effect of different environmental conditions on their UV-photodegradation behaviour, 3) monitoring the primary elimination of TMP, DMI and CPTX during photodegradation and biodegradation tests using HPLC, and measuring their degree of mineralization by means of dissolved organic carbon analyser (DOC), 4) elucidating the structures of the TPs which formed during the degradation of TMI, DMI and CPTX by using LC-MS/MS analysis, 5) analysing the biodegradability of their TPs by laboratory tests and in-silico assessments in order to determine the fate and persistence of these TPs in the aquatic environment, 6) conducting in-silico toxicity predictions for the selected psychotropic drugs and their TPs in human (carcinogenicity, genotoxicity and mutagenicity) and in eco-system (toxicity to microorganisms and toxicity in rainbow trouts). TMP, DMI and CPTX were found to be not readily biodegradable in Closed Bottle test (CBT), and in Manometric Respiratory test (MRT). They did not show any significant elimination or mineralization within 128 minutes of irradiation using a xenon Lamp. In UV-photodegradation samples, LC-MS/MS results showed elimination of the three psychotropic drugs with corresponding comparatively lower degrees of mineralization indicating formation of abundant photo-TPs. From the UV-photolysis tests, which were carried out under different environmental conditions, it can be concluded that the degradation rates of TMP, DMI and CPTX decreased when their initial concentrations increased. pH affected the photodegradation behaviour of TMP, DMI and CPTX with different pattern depending on many factors such as solubility, molar absorption coefficient (ɛ), ionisation form and chemical structure. Temperature elevation showed non-significant effect on the photodegradation performance of DMI and CPTX, while showed an enhanced effect on the photodegradation performance of TMP. This could be because the molecules of DMP and CPTX can reach the sufficient energy required for degradation at low temperature. While TMP`s molecules still require some more energy to undergo degradation and temperature helps them to reach easily these required activation energy. Elucidating the TPs and studying the degradation pathways for TMP, DMI and CPTX during UV irradiation indicated that hydroxylation is the most abundant pathway followed by oxidation and isomerization. De-chlorination pathway was observed during the UV-transformation of CPTX. III Deamination and loss of the aliphatic side chain were observed only during the UV-transformation of TMP, while not observed during DMI and CPTX transformation. This indicates that the bond between the amino- group and the aliphatic side chain in DMI and CPTX can be more resistant to photodegradation compared to the same bond in TMP. This could be due to the presence of extra methyl groups in TMP molecule which can decrease the previously mentioned bond strength. Biodegradation tests performed for photodegradation mixtures, which contain the psychotropic drugs and their TPs, showed low biodegradation results. Despite that, elimination of some TPs was observed in the LC-MS/MS analysis at the end of these biodegradation tests. This indicates the probability of biodegradation ability for some TPs and this ability was hindered by the predominant effect of other non-biodegradable compounds. In-silico predictions showed that for many endpoints, photo-transformation might lead to an increased toxicity in humans and to water organisms compared with the parent compound. As an overall conclusion, the present work demonstrates that a combination of laboratory simulation tests, LC-MS/MS analysis and in-silico tools result in valuable new information regarding environmental fate of three important psychotropic drugs and their TPs. This dissertation also highlights that different environmental conditions such as temperature, initial drug concentration and pH can differently affect the degradation behaviour of pharmaceuticals even when they are highly structurally related. Therefore, one cannot conclude from one pharmaceutical to another but each one needs to be investigated individually and this present a great challenge for risk assessment kinetics of chemicals in the aquatic environment. The results presented here showed that the investigated pharmaceuticals and their TPs can negatively affect the environment which may be harmful to the ecosystem as they might have been present for decades in the aquatic environment without any knowledge of their environmental fate or connected risk. Therefore, further work needs to be done including analysis of environmental samples (e.g., surface waters), as well as laboratory toxicity tests to further expand knowledge on their exact environmental impact.