Viele Kommunen wenden sich im Zuge von Klimaanpassungsmaßnahmen dem Schwammstadt -konzept zu. Aufgrund der vielen dabei zu berücksichtigenden Einflussfaktoren benötigt eine wassersensible Stadt- und Regionalentwicklung eine Komplexitätsanalyse und Maßnahmenbündelung

Economy and society are currently exposed to multi-layered multi-crises. Against the backdrop of the covid pandemic, a growing shortage of skilled workers, increasing armed conflicts or persistent refugee flows, cities and municipalities in particular have to deal with resulting local impacts. Parallel to these highly dynamic crisis events, cities and municipalities continue to be called upon to face the now established challenges of climate change, sustainability and digitalization. More and more, there are organizational and also psychological overloads in coping with everyday tasks as a result of increasing complexities. Because of the excessive demands, there is a retreat to familiar and routinerelated everyday work and the neglect of the search for adequate solutions to the increasingly complex problems. Especially in the field of municipal infrastructure, which requires rapid and comprehensive adaptation to the manifold impacts of climate change, this excessive demand increasingly leads to recourse to rather simple solutions, which, however, do not justice to the complexity of the situation. During two certificate courses at Hof University of Applied Sciences (Germany) on the development of climate-adapted urban planning and on successful digitalization in municipal water management, a novel tool for dealing with complex situations was developed to practice on examples. It was observed among the approximately 70 participants in both courses that used this method two to three times already led to a visible change in the perception and assessment of complex situations, without the need for psychologically accompanied training of change behavior.

This study investigates the performance of a newly developed flow-through reactor and the utilized photocatalytic materials in two environments: a lab-scale experiment and a pilot-scale experiment in a contaminated building. The aim was to assess the removal of polycyclic aromatic hydrocarbons from the air using an innovative reactor equipped with an ultraviolet-irradiated titanium dioxide catalyst. Empirical measurements were conducted in the laboratory to revise the developed fixated titanium dioxide catalysts at different irradiances. Naphthalene and 1-methylnaphthalene elimination were used as model substances due to being the most volatile polycyclic aromatic hydrocarbons (PAH). In addition, they are often found in contaminated buildings. Tests in an office building revealed high suitability of the air cleaning system for low polycyclic aromatic hydrocarbons concentrations with a degradation of the compounds below the allowed limits of indoor air pollutants set by the German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety. The degradation of the organic micropollutants proceeded without detection of by-products, so that mineralization can be assumed. Based on these observations and a large number of previous studies, detailed degradation pathways for the selected micropollutants were also established.

Der Klimawandel ist in den vergangenen Jahren auch in Europa immer sichtbarer geworden. Die deutlichsten Auswirkungen zeigen sich für die Wasserwirtschaft in den beiden extremen Formen Starkregen und Trockenheit. Die Trockenperioden in den Jahren 2018 und 2019 sowie die schweren Überschwemmungsereignisse in 2021 an der Ahr, der Erft und anderswo haben auf Seiten der Fachwelt die Sensibilität für die Auswirkungen dieser Wetterextreme weiter gesteigert. Mehr und mehr werden Lösungen zur Vorbeugung und Anpassung an die erwartete Zunahme solcher Ereignisse entwickelt. Viele deutsche Bundesländer stellen beispielsweise für die Erstellung von Starkregengefahrenkarten umfangreiche Fördermittel zur Verfügung. Die erforderlichen Bemühungen beschränken sich aber nicht nur auf erforderliche Maßnahmen bei Extremwetterereignissen. Zunehmend müssen (ab-)wasserwirtschaftliche Einrichtungen effizienter gestaltet werden, da sie nach wie vor einen erheblichen Energieverbraucher insbesondere in kleinen und mittelgroßen Gemeinden darstellen. Hier leistet die Wasserwirtschaft seit vielen Jahren einen wichtigen Beitrag zur Reduzierung von CO2 durch stetig zunehmende Effizienzsteigerungen in technischen Einrichtungen. Dabei nimmt die Digitalisierung wie in anderen Wirtschafts- und Gesellschaftssektoren eine besondere Stellung bei der Entwicklung passender und wirksamer Lösungen ein. Forscher der Hochschule Hof haben im Rahmen des Vorhabens „WaterExe4.0“ (gefördert vom Bundesministerium für Bildung und Forschung) eine erste Metastudie zur Digitalisierung in der deutschsprachigen Wasserwirtschaft erstellt. In dieser Studie stellte sich heraus, dass trotz erheblicher Entwicklungsschübe in den letzten Jahren und Zunahme der Lösungsangebote auf den ersten Blick noch eine große Lücke zwischen Angebot und Umsetzung besteht. Ein realer Anwendungsbezug konnte nur für 11 % der rund 700 identifizierten Produkte, Projekte und Studien identifiziert werden. Um die Gründe für dieses scheinbare Ungleichgewicht herauszufinden, erfolgte die ergänzende Befragung von Expert:innen der Wasserwirtschaft. Die Antworten zeigten diesbezüglich beispielsweise auf, dass alltägliche Probleme zu wenig oder kaum in neuen Lösungen berücksichtigt werden, was die Anwender:innen stark überfordert. Weiterhin wird der Mehrwert einer Digitalisierungslösung für die jeweilige individuelle Situation noch immer zu wenig sichtbar. Zudem fehlen systematische Analysetools, um wesentliche Hindernisse infolge neuer Ideen zu identifizieren und den besten Weg für den Start und die Umsetzung eines Digitalisierungsprojekts zu finden. Die Komplexität des Themas führte dazu, dass die Studie „WaterExe4.0“ mithilfe von vier methodisch unterschiedlichen Teilerhebungen (Literatur- und Marktrecherche, Befragung, Expert:inneninterview und Workshops) durchgeführt wurde. Die Ergebnisse geben damit einen umfangreichen Überblick über die aktuelle Situation in der deutschsprachigen Wasserwirtschaft und zeigen die Erwartungen der Branchenteilnehmer für die Zukunft auf.

Supported titanium dioxide-based photocatalysts were investigated for the degradation of pharmaceuticals under irradiation with UV−A LEDs. Focus of the presented research was placed on the degradation kinetics under different matrix influences and energy flux densities of UV−A radiation. The chemical parameters, pH, orthophosphate, nitrogen concentration and background organic concentration were investigated. The results were evaluated by time-resolved measurement of the concentrations and by calculating and plotting the first-order degradation rate. The results showed clear differences in the rates of degradation of each compound, with diclofenac being the most easily degraded and metoprolol the most resistant. When the influence of energy flux density was examined, a linear relationship between degradation rate and the square root of energy flux density was confirmed. The organic background matrix has a strong influence on the degradation kinetics of the compounds. Nitrogen and orthophosphate slow down the degradation much less than the organic background matrix. Investigating the pH influence, it could be shown that almost no degradation is detected in the basic pH range. The results were illustrated with the help of a radar diagram, which can show all dependencies at a glance.

In the present work, a suitable experimental setup was developed to successfully apply advanced oxidation processes (AOP) to real groundwater matrices. This setup combines an O3-bubble column reactor with a carrier-bound TiO2/UV-system. The degradation of various chlorinated ethene and methane derivatives commonly found of chlorinated volatile organic compound polluted regional groundwater samples was investigated. Because of known issues within water remediation using AOP such as toxification by transformation products, this study aimed at complete mineralization of the contained organic micropollutants. Moreover, the influences of variable process parameters such as flow rate, ozone concentration, and radiation dose on process performance were statistically evaluated and discussed. Parameter optimization using a Box-Behnken experimental design resulted in very promising degradation rates. It was thus possible to achieve a degradation rate of at least 98% for cis-dichloroethene, trichloroethene and tetrachloroethene and 85% for trichloromethane without formation of transformation products. The results of this work open up the possibility of developing innovative technologies based on AOP, which can be universally applied even to challenging matrices such as groundwater.

Immobilized titanium dioxide catalysts were used within a photocatalytic immersion rotary body reactor, which was connected to a substream ozonation unit to remove micro-pollutants from wastewater. Within this work data on the behavior of cumulative parameters during treatment of wastewater by photocatalysis and photocatalytic ozonation are provided. The investigated parameters are spectral absorption coefficient at 254 nm (SAC254), total organic carbon (TOC) and chemical oxygen demand (COD). All experiments were carried out using secondary effluent from the same wastewater treatment plant. For the parameter SAC254, consistent concentration curves and dependencies to operational parameters of the experimental system could be measured. The measurements of the parameters TOC and COD showed greater uncertainties, although basic trends could nonetheless be observed. A good linear correlation (R2 < 0.85) between the reduction of SAC254 and 8 micro-pollutants for photocatalysis and photocatalytic ozonation was found. This confirms the suitability of the SAC254 as a control parameter for a large-scale application of a photocatalytic 4th treatment stage. A linear correlation between measured TOC and COD degradation rates was possible with a coefficient of determination of 0.58–0.86. The simultaneous decrease of TOC and COD is an indicator for a mineralization of the treated wastewater matrix.