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Ergebnisse nach Hochschule und Institut
Publikation Circularity and environmental sustainability of organic and printed electronics(Jenny Stanford Publishing, 2024) Le Blévennec, Kévin; Hengevoss, Dirk; Zimmermann, Yannick-Serge; Brun, Nadja; Hugi, Christoph; Lenz, Markus; Corvini, Philippe; Fent, Karl; Nisato, Giovanni; Lupo, Donald; Rudolf, SimoneIn this chapter, the possible role and impact of organic and printed electronics (OPE) in a transition toward a circular economy and more sustainable society will be discussed. The learning targets are twofold: first, understanding main environmental issues associated with the emerging field of OPE, and second, identifying, through a systemic perspective, the enabling potential of these technologies.04A - Beitrag SammelbandPublikation 01B - Beitrag in Magazin oder ZeitungPublikation Guidelines on pre- and co-processing of waste in cement production. Use of waste as alternative fuel and raw material(Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH, 2020) Hinkel, Michael; Blume, Steffen; Hinchliffe, Daniel; Mutz, Dieter; Hengevoss, DirkThe main objective of these Guidelines is to improve waste management by offering updated and objective information about pre- and co-processing of waste in the cement industry. They contain knowhow and practical experiences gained in implementing pre- and co-processing since the first edition that served as a reference document in international agreements (e.g. Basel Convention for Hazardous Waste Treatment) and adaptation of various national guidelines. The Guidelines follow common understanding that avoiding and reducing waste is the best way of dealing with current waste problems all over the world. The extension of waste collection to 100% of the population and of waste fractions is notably a prerequisite to manage waste effectively in many countries. However, the Guidelines promote an approach that aims to reduce existing waste problems and at the same time to encourage the use of waste as an alternative source for primary energy and virgin raw materials in cement production. Wherever possible, the concepts of resource efficiency, circular economy, recycling and reuse must be given first priority. Improving waste management will take time. Reaching the status of an effective waste management solution in Europe has taken place over a period of 20-30 years. It has been supported by stringent legislation to monitor quality and emissions. Developing pre- and co-processing as a suitable waste management option requires also time and investments. Rigorous permitting and quality assurance procedures need to be applied. Pre- and coprocessing respects the waste hierarchy and does not contradict it, when these Guidelines are followed. In this context, it can be classified as a technology for energy recovery and mineral recycling. The key for implementation of these Guidelines and to achieve the maximum benefit from pre- and co-processing of waste in cement production continues to be close collaboration and co-operation between the public and the private sectors. Innovative techniques and technical knowhow are available and will be further developed by the private ector, whereas the public sector should ensure that environmental standards are maintained and health and safety regulations are applied and enforced. In addition ethical business conduct, good governance and social responsibility remain prerequisites for successfully implementing the Guidelines.05 - Forschungs- oder ArbeitsberichtPublikation Life cycle assessment of a novel production route for scandium recovery from bauxite residues(Elsevier, 2024) Hengevoss, Dirk; Misev, Victor; Feigl, Viktória; Fekete-Kertész, Ildikó; Molnár, Mónika; Balomenos, Efthymios; Davris, Panagiotis; Hugi, Christoph; Lenz, MarkusScandium (Sc) has various technological applications, but the concentrations of Sc in ores are low. Both, the mining of low concentrated Sc and the production of industrial-grade Sc are a heavy burden on the environment. Bauxite residue (BR) from alumina production represents one of the major sources of Sc in Europe (Ochsenkühn-Petropulu et al., 1994). The goal of this study is to assess the environmental impacts from cradle to gate of a novel production route developed in the Scandium Aluminium Europe project (SCALE) to extract Sc at concentrations <100 ppm from BR, to concentrate and upgrade it to pure ScF3 and Sc2O3 and ultimately to refine it to an aluminium scandium master alloy with 2 % Sc mass fraction (AlSc2 %). Results show that the global warming potential (GWP), measured in CO2-eq per kg Sc2O3, generated with the novel route is about half the GWP of the state-of-the-art Sc2O3 production from rare earth tailings when applying equal allocation principles. The initial process step to dissolve BR and extract Sc consumes elevated amounts of acid and energy and is responsible for at least 80 % of the route’s total environmental impact. The amount of the generated filter cake (FC) is equal to the amount of the BR input and is a potential resource for cement clinker production. The ecotoxicological study indicates that both FC and BR are slightly ecotoxic.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Opciones para el aprovechamiento energético de residuos en la gestión de residuos sólidos urbanos. Guía para los responsables de la toma de decisiones en países en vías de desarrollo y emergentes(Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH, 2017) Mutz, Dieter; Hengevoss, Dirk; Hugi, Christoph; Gross, Thomas05 - Forschungs- oder ArbeitsberichtPublikation Scattered and transmitted light as surrogates for activated carbon residual in advanced wastewater treatment processes. Investigating the influence of particle size(Elsevier, 04/2024) Kirchen, Franziska; Fundneider, Thomas; Gimmel, Louis; Thomann, Michael; Pulfer, Michael; Lackner, SusanneThe use of powdered activated carbon (PAC) is a common process in advanced wastewater treatment to remove micropollutants. Retention and separation of PAC is essential as PAC loaded with micropollutants should not be released into the environment. Determining the activated carbon (AC) residual in the effluent poses a challenge, as there is currently no on-line measurement method. In this study, the correlation between turbidity, measured by scattered light, and absorption at wavelength of 550 nm (Absorption550 nm), measured by transmitted light, was investigated in relation to the AC residue. Linear correlations for turbidity (R2 = 0.95) and Absorption550 nm (R2 = 1.00) to AC concentrations were observed in both laboratory and full-scale experiments in a pilot plant where superfine PAC was added prior to Pile Cloth Media Filtration (PCMF). Decreasing the particle size (d50) while maintaining the same AC concentration leads to increased turbidity: Therefore, a fourfold reduction in d50 results in a 2- to 3-fold increase in turbidity, whereas a 30-fold reduction in d50 leads to a 6-to 8-fold increase. Furthermore, the original wastewater turbidity led to a parallel shift in the linear correlation between turbidity and AC. Coagulant doses of up to 400 mg Me3+/g AC resulted in a 50% reduction in turbidity. However, higher concentrations from 400 to 1,000 mg Me3+/g AC resulted in increased turbidity with only a 30% reduction compared to the initial turbidity. The study also highlights the significance of AC particle size in optical measurements, impacting result accuracy.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Progress in sensor technology - progress in process control? Part I: Sensor property investigation and classification(IWA Publishing, 2003) Rieger, Leiv; Alex, Jens; Winkler, S.; Boehler, Marc; Thomann, Michael; Siegrist, H.To ensure correctly operating control systems, the measurement and control equipment in WWTPs must be mutually consistent. The dynamic simulation of activated sludge systems could offer a suitable tool for designing and optimising control strategies. Ideal or simplified sensor models represent a limiting factor for comparability with field applications. More realistic sensor models are therefore required. Two groups of sensor models are proposed on the basis of field and laboratory tests: one for specific sensors and another for a classification of sensor types to be used with the COST simulation benchmark environment. This should lead to a more realistic test environment and allow control engineers to define the requirements of the measuring equipment as a function of the selected control strategy.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Spectral in-situ analysis of NO2, NO3, COD, DOC and TSS in the effluent of a WWTP(IWA Publishing, 2004) Rieger, Leiv; Langergraber, Günter; Thomann, Michael; Fleischmann, Nikolaus; Siegrist, HansruediAn in-situ UV spectrometer was applied to the effluent of a WWTP in Switzerland and calibrated using a multivariate calibration algorithm based on PLS regression. Except for nitrite, the calibration was based on comparative measurements of the effluent in the plant laboratory. Samples made of stock solution added to three different matrices prepared in the EAWAG laboratory were used for the nitrite calibration because the effluent concentrations were always in the range of 0.06–0.26 mg/l. The results show very good precision for nitrite and nitrate. The measuring range for COD and DOC was not completely covered by the measurements, so the meaningfulness of the results is limited. Nevertheless the precision obtained for soluble COD is high enough for most applications at WWTPs. The accuracy of the TSS measurement is unsatisfactory as regards effluent limits since the spectrometer used does not cover the wavelength region up to 700 nm, which gives better signals for TSS calibration due to its strong correlation with turbidity.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Computer-aided monitoring and operation of continuous measuring devices(IWA Publishing, 2004) Rieger, Leiv; Thomann, Michael; Joss, Adriano; Gujer, Willi; Siegrist, HansruediExtended studies of measuring and control systems in activated sludge plants at EAWAG revealed that the measuring devices remain the weakest point in control applications. To overcome this problem, a software package was developed which analyses and evaluates the residuals between a reference measurement and the sensor and collects the information in a database. The underlying monitoring concept is based on a two-step evaluation of the residuals by means of statistical evaluations using control charts with two different sets of criteria. The first step is a warning phase in which hints on probable errors trigger an increase in the monitoring frequency. In the second step, the alarm phase, the error hypothesis has to be validated and should allow immediate and targeted reactions from the operator. This procedure enables an optimized and flexible monitoring effort combined with an increased probability of early detection of systematic measuring errors. Beside the monitoring concept, information about the measuring device, the performed servicing actions and the responsibilities is stored. Statistical values for the quantitative characterization of the measuring system during operation will be given. They are needed to parameterise controllers or to guarantee the accuracy of the instrument in order to allow reliable calculations of effluent tax. In contrast to other concepts, not only is the measuring device examined under standard conditions, but so is the entire measuring chain from the liquid to be analysed to the value stored in the database of the supervisory system. The knowledge of the response time of the measuring system is then required in order to allow a comparison of the corresponding values.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Quantifying the uncertainty of on-line sensors at WWTPs during field operation(Elsevier, 12/2005) Rieger, Leiv; Thomann, Michael; Gujer, Willi; Siegrist, HansruediIt remains an ongoing task to quantify the uncertainty of continuous measuring systems at WWTPs during field operation. The commonly used methods are based on lab experiments under standardized conditions and are only suitable for characterizing the measuring device itself. For measuring devices under field conditions, a knowledge of the response time, trueness and precision is equally important. A method is proposed which can be used to characterize newly installed on-line sensors or to evaluate monitoring data which may contain systematic errors. The concept is based on comparative measurements between the sensor and a reference. A linear regression is used to differentiate between trueness and precision. Various statistical tests are conducted to validate the preconditions of linear regression. The information about the trueness and precision of the measuring system under field conditions helps to adapt control strategies more effectively to the relevant processes and permits sophisticated control concepts. Moreover, the concept can help to define guidelines for evaluating the uncertainties of effluent quality monitoring to overcome the concerns about on-line sensors, improve the trust in these systems and to allow the use of continuously measuring systems for legislative purposes. The approach is discussed in detail in this paper and all statistical tests and formulas are listed in the Appendix.01A - Beitrag in wissenschaftlicher Zeitschrift