Inputs zur gesellschaftlichen Entscheidungsfindung

The characteristics of fecal sludge delivered to treatment plants are highly variable. Adapting treatment process operations accordingly is challenging due to a lack of analytical capacity for characterization and monitoring at many treatment plants. Cost-efficient and simple field measurements such as photographs and probe readings could be proxies for process control parameters that normally require laboratory analysis. To investigate this, we evaluated questionnaire data, expert assessments, and simple analytical measurements for fecal sludge collected from 421 onsite containments. This data served as inputs to models of varying complexity. Random forest and linear regression models were able to predict physical-chemical characteristics including total solids (TS) and ammonium (NH₄⁺-N) concentrations, and solid-liquid separation performance including settling efficiency and filtration time (R² from 0.51-0.66) based on image analysis of photographs (sludge color, supernatant color, and texture) and probe readings (conductivity (EC) and pH). Supernatant color was the best predictor of settling efficiency and filtration time, EC was the best predictor of NH₄⁺-N, and texture was the best predictor of TS. Predictive models have the potential to be applied for real-time monitoring and process control if a database of measurements is developed and models are validated in other cities. Simple decision tree models based on the single classifier of containment type can also be used to make predictions about citywide planning, where a lower degree of accuracy is required.

A timely transition of socio-technical systems to more sustainable alternatives is crucial in mitigating climate change and other environmental problems. While innovation plays a significant role in such transitions, policy makers and the scientific community have become increasingly aware that the deliberate destabilization of existing socio-technical regimes—including associated institutions and technologies—is also often necessary. However, such aspiration is politically contested. This paper presents the Endowment-Practice-Institutions (EPI) Framework to study the contestation of institutions underpinning socio-technical regimes. By integrating key theories from Institutional Sociology and Political Economy, the framework conceives actors' capability of influencing institutional structures to be dependent on their institutional work practices and the various endowments that enable these practices. We present Japanese coal policy as an example to illustrate how the framework can be used to assess actors' institutional work and their influence on institutional outcomes. In addition to providing new theoretical insights, the framework helps to systematically analyze agency-driven mechanisms pertinent for the maintenance or destabilization of socio-technical regimes.

Monitoring access to drinking water is complex, especially in settings where on premises water supply is not available. Although self-reported data are generally used to estimate coverage of access to drinking water, the relationship between self-reported time travelled and true time travelled is not well known in the context of water fetching. Further, water fetching is likely to impact the quantity and quality of water a household uses, but data and measures supporting this relationship are not well documented. The objective of this study was to appraise the validity and reliability of self-reported measurements used to estimate access coverage. A case study was conducted in Malawi to enhance understanding of the self-reported measures and alternatives available to assess and monitor access to drinking water in view of generating global estimates. Self-reported data were compared with objective observations and direct measurements of water quantity, quality and accessibility. Findings from this study highlight the variations between different measures such as self-reported and recorded collection time and raise awareness with regard to the use of self-reported data in the context of fetching water. Alternatives to self-reported indicators such as GPS-based or direct observations could be considered in surveys in view of improving data accuracy and global estimates.

To prioritise sustainable sanitation systems in strategic sanitation planning, indicators such as local appropriateness or resource recovery have to be known at the pre-planning phase. The quantification of resource recovery remains a challenge because existing substance flow models require large amounts of input data and can therefore only be applied for a few options at a time for which implementation examples exist. This paper aims to answer two questions: How can we predict resource recovery and losses of sanitation systems ex-ante at the pre-planning phase? And how can we do this efficiently to consider the entire sanitation system option space? The approach builds on an existing model to create all valid sanitation systems from a set of conventional and emerging technologies and to evaluate their appropriateness for a given application case. It complements the previous model with a Substance Flow Model (SFM) and with transfer coefficients from a technology library to quantify nutrients (phosphorus and nitrogen), total solids (as an indicator for energy and organics), and water flows in sanitation systems ex ante. The transfer coefficients are based on literature data and expert judgement. Uncertainties resulting from the variability of literature data or ignorance of experts are explicitly considered, allowing to assess the robustness of the model output. Any (future) technologies or additional products can easily be added to the library. The model is illustrated with a small didactic example showing how 12 valid system configurations are generated from a few technologies, and how substance flows, recovery ratios, and losses to soil, air, and water are quantified considering uncertainties. The recovery ratios vary between 0 and 28% for phosphorus, 0–10% for nitrogen, 0–26% for total solids, and 0–12% for water. The uncertainties reflect the high variability of the literature data but are comparable to those obtained in studies using a conventional post-ante material flow analysis (generally about 30% variability at the scale of a an urban area). Because the model is fully automated and based on literature data, it can be applied ex-ante to a large and diverse set of possible sanitation systems as shown with a real application case. From the 41 technologies available in the library, 101,548 systems are generated and substance flows are modelled. The resulting recovery ratios range from nothing to almost 100%. The two examples also show that recovery depend on technology interactions and has therefore to be assessed for all possible system configurations and not at the single technology level only. The examples also show that there exist trade-offs among different types of reuse (e.g. energy versus nutrients) or different sustainability indicators (e.g. local appropriateness versus resource recovery). These results show that there is a need for such an automated and generic approach that provides recovery data for all system configurations already at the pre-planning phase. The approach presented enables to integrate transparently the best available knowledge for a growing number of sanitation technologies into a planning process. The resulting resource recovery and loss ratios can be used to prioritise resource efficient systems in sanitation planning, either for the pre-selection or the detailed evaluation of options using e.g. MCDA. The results can also be used to guide future development of technology and system innovations. As resource recovery becomes more relevant and novel sanitation technologies and system options emerge, the approach presents itself as a useful tool for strategic sanitation planning in line with the Sustainable Development Goals (SDGs).

Background: Products made from recycled organic materials are an important part of a circular economy, but the question is whether they will be adopted by the public. Such products can elicit strong emotional responses and public resistance. As a case in point, we studied products made from sewage waste, such as recycled toilet paper, which can serve as material alternative to wood and plastic when making household items (e.g., tables). In an experimental study, we investigated the role of values in emotional responses to such wastewater products, and whether emotional responses were influenced by value-tailored messages. We expected that people would experience positive emotions towards products that supported their values, especially when the messages emphasised the benefits of these products for their values (e.g., when the products were presented as good for the environment). We presented participants with one of two messages describing wastewater products as having positive implications for either biospheric values (i.e. positive consequences for the environment) or hedonic values (i.e. positive consequences for personal enjoyment). We predicted that the relationship between values and positive emotions would be stronger when the messages emphasised the positive implications of wastewater products for one's core values. Additionally, we predicted that emotions would be associated with acceptability and intentions to purchase the products.
Results: The more strongly people endorsed biospheric values, the more positive emotions they reported towards wastewater products. As expected, this relationship was stronger when the environmental benefits of products were emphasised. Hedonic values were significantly but weakly associated with more negative and more positive emotions, and this did not depend on the message framing. However, we found that emphasising pleasurable benefits of wastewater products reduced positive emotions in people with weaker hedonic values. Positive and negative emotions were significantly associated with higher and lower acceptability of the products and intentions to purchase the products, respectively.
Conclusions: Our findings have implications for the effective marketing of wastewater products. For people with strong biospheric values, emphasising the positive environmental consequences may promote wastewater products. Such biospheric messages do not seem to make the products less (or more) appealing for people with strong hedonic values, who do not generally have strong emotional responses to these products. We discuss the theoretical implications of our findings and avenues for future research.