@phdthesis{Sorge2006, author = {Sorge, Hans-Christian}, title = {Technische Zustandsbewertung metallischer Wasserversorgungsleitungen als Beitrag zur Rehabilitationsplanung}, doi = {10.25643/bauhaus-universitaet.813}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20070516-8681}, school = {Bauhaus-Universit{\"a}t Weimar}, year = {2006}, abstract = {Die Instandhaltung der st{\"a}dtischen Trinkwassernetze ist Aufgabenschwerpunkt der Wasserversorgungsunternehmen bzw. Netzbetreiber. Dazu notwendige Rehabilitationsplanungen st{\"u}tzen sich zurzeit weitgehend auf die Trendprognose von Schadensraten und die Erfahrungen der Mitarbeiter. Der Einfluss wesentlicher Kenngr{\"o}ßen wie Werkstoffeigenschaften oder die Resttragf{\"a}higkeit des Rohres bleiben hierbei gr{\"o}ßtenteils unber{\"u}cksichtigt. {\"U}ber materialtechnische Untersuchungen werden die notwendigen Kenngr{\"o}ßen ermittelt, die eine zuverl{\"a}ssige Bewertung des technischen Zustands des Rohrstrangs erm{\"o}glichen. So lassen sich die Prognose der technischen Nutzungsdauer und Rehabilitationsplanungen auf eine solide Basis stellen. In dieser Dissertationsschrift wird hierzu ein Untersuchungs- und Bewertungsalgorithmus mit integrierten Prognoseverfahren erarbeitet.}, subject = {Instandhaltungsplanung}, language = {de} } @misc{Schaefer2005, type = {Master Thesis}, author = {Sch{\"a}fer, Robert Christian}, title = {Phosphordynamik in naturnahen Schwimm- und Badeteichen}, doi = {10.25643/bauhaus-universitaet.560}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-5601}, school = {Bauhaus-Universit{\"a}t Weimar}, year = {2005}, abstract = {Mit dieser Diplomarbeit werden die wichtigsten limnologischen Wechselwirkungen eines Gew{\"a}sser- {\"O}kosystems und der beteiligten Organismen ausf{\"u}hrlich dargestellt. Dabei ist der „N{\"a}hrstoffabbau" speziell des Phosphors durch Plankton, Algen und Wasserpflanzen sowie dessen Einflussfaktoren wesentlich. In diesem Zusammenhang spielt die Phosphordynamik zwischen Gew{\"a}sser, Sediment und Organismen eine entscheidende Rolle. Anhand ausgew{\"a}hlter Th{\"u}ringer Badegew{\"a}sser wird der Zusammenhang zwischen dem Phosphorgehalt und der Cyanobakterien- Dominanz untersucht. Von Bedeutung sind weitere hygienische Parameter der Wasserqualit{\"a}t. M{\"o}gliche Aussagen bei der Analyse der oligotrophen, nat{\"u}rlichen Badegew{\"a}sser werden auf die naturnahen Schwimm- und Badeteiche {\"u}bertragen. Da Schwimm- und Badeteiche k{\"u}nstlich errichtete Bauwerke sind, sind Aspekte der anthropogenen Nutzung bedeutsam. Hierzu z{\"a}hlen die Bauformen bzw. Gr{\"o}ßenver-h{\"a}ltnisse und der Technikeinsatz. Es wird gepr{\"u}ft, ob aufgrund vorliegender Daten be-z{\"u}glich des Eintrages und der Elimination eine Bilanzierung des Phosphors in Schwimm- und Badeteichanlagen m{\"o}glich ist. Als Ergebnis dieser Diplomarbeit werden Empfehlungen zu Errichtung und Betrieb von Schwimm- und Badeteichen erarbeitet, die den {\"u}berwachungsbed{\"u}rftigen Parameter Phosphor betreffen.}, subject = {Funktionsprinzipien}, language = {de} } @article{SchwenkeSoebkeKraft, author = {Schwenke, Nicolas and S{\"o}bke, Heinrich and Kraft, Eckhard}, title = {Potentials and Challenges of Chatbot-Supported Thesis Writing: An Autoethnography}, series = {Trends in Higher Education}, volume = {2023}, journal = {Trends in Higher Education}, number = {Volume 2, issue 4}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/higheredu2040037}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20231207-65016}, pages = {611 -- 635}, abstract = {The release of the large language model-based chatbot ChatGPT 3.5 in November 2022 has brought considerable attention to the subject of artificial intelligence, not only to the public. From the perspective of higher education, ChatGPT challenges various learning and assessment formats as it significantly reduces the effectiveness of their learning and assessment functionalities. In particular, ChatGPT might be applied to formats that require learners to generate text, such as bachelor theses or student research papers. Accordingly, the research question arises to what extent writing of bachelor theses is still a valid learning and assessment format. Correspondingly, in this exploratory study, the first author was asked to write his bachelor's thesis exploiting ChatGPT. For tracing the impact of ChatGPT methodically, an autoethnographic approach was used. First, all considerations on the potential use of ChatGPT were documented in logs, and second, all ChatGPT chats were logged. Both logs and chat histories were analyzed and are presented along with the recommendations for students regarding the use of ChatGPT suggested by a common framework. In conclusion, ChatGPT is beneficial for thesis writing during various activities, such as brainstorming, structuring, and text revision. However, there are limitations that arise, e.g., in referencing. Thus, ChatGPT requires continuous validation of the outcomes generated and thus fosters learning. Currently, ChatGPT is valued as a beneficial tool in thesis writing. However, writing a conclusive thesis still requires the learner's meaningful engagement. Accordingly, writing a thesis is still a valid learning and assessment format. With further releases of ChatGPT, an increase in capabilities is to be expected, and the research question needs to be reevaluated from time to time.}, subject = {Chatbot}, language = {en} } @phdthesis{Pang2008, author = {Pang, Zhiqi}, title = {Phosphorus enrichment in the treatment of pig manure in China using anaerobic digestion technology}, doi = {10.25643/bauhaus-universitaet.1293}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20080704-13640}, school = {Bauhaus-Universit{\"a}t Weimar}, year = {2008}, abstract = {Phosphorus (P) is a key irreplaceable nutrient element in all life forms. Almost all phosphorus used by society is mined from non-renewable phosphate rock. Approximately 80\% of global phosphate rock consumption is used for fertilizer production. However, as a finite resource, the world phosphate reserve could be exhausted within the next 100-250 years. The phosphate resource in China is also limited. The exploitable deposits could be exhausted within 70 years. Investigations show that the largest recoverable phosphate resource in China is found in animal manure. It was estimated that the potential phosphate resource in intensive-scale animal plants accounts for 47\% of the total consumption of phosphate rock of the country each year. Pig manure contains phosphorus and nitrogen in high concentration. The objective of this study is to investigate forced P-precipitation in pig manure combined with anaerobic digestion; when biogas is generated, an enriched P-containing digested manure sludge can be obtained. Anaerobic digestion experiments indicated that total concentrations of phosphorus (TP) and kjeldahl nitrogen (TKN) remained basically constant before and after anaerobic digestion. However, the composition of nitrogen and phosphorus in digested manure was quite different; 37.7\% of phosphorus existed as PO4-P in the raw pig manure, whilst 20.8\% of PO4-P was present in the digested pig manure. NH4-N accounted for 50.4\% of the total TKN in raw pig manure, while most of the TKN in digested manure (79.3\%) was composed of NH4-N. The pH value of pig manure rose by 0.88 units after anaerobic digestion. PO4-P was reduced by 45\% during anaerobic digestion. The average molar ratios of Mg/P and Ca/P achieved were 1.3 and 1.7. It was found that solid/liquid separation has little influence on the change in the molar ratios. The optimal position for P-precipitation is after anaerobic digestion. P-precipitation should be conducted in homogeneous digested pig manure. The ideal pH range for P-precipitation is between 8.0 and 9.5. In the pH range of 8.8-9.5, struvite precipitation dominates the precipitation reaction. The existence of calcium ions results in competitive reaction with magnesium ions. In the pH range of 8.0-8.8, calcium phosphate was apt to form. Both MgCl2•6H2O and MgO can be adopted as a magnesium source. MgO is suitable for supplementation in raw manure. Without the addition of other alkali, the pH value rose to 8.5. Nearly 85\% of soluble phosphorus (PO4-P) could be removed from liquid portion. MgCl2•6H2O has good solubility. When MgCl2•6H2O was used at a pH value of 9.0, the equilibrium time required was 30 minutes. The appropriate Mg2+/PO4-P molar ratio was 1.3. Under these conditions, whether with raw or digested manure, 90\% of PO4-P could be removed. Forced P-precipitation combined with anaerobic digestion is suitable for application in China. More than 90\% of the soluble phosphorus could be removed from the liquid portion of pig manure through forced P-precipitation. With the aid of flocculants, 95.7\% of the total phosphorus could be precipitated in the final manure solid.}, language = {en} } @phdthesis{Nayono, author = {Nayono, Suwartanti}, title = {Development of a Sustainability-based Sanitation Planning Tool (SusTA) for Developing Countries}, doi = {10.25643/bauhaus-universitaet.2222}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20140619-22227}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {153; mit Anh{\"a}ngen 209}, abstract = {Background and Research Goal Despite all the efforts in the sanitation sector, it is acknowledged that the world is not on track to meet the MDG sanitation target to reduce the number of people without access to sanitation by 2015. Furthermore, a large number of existing sanitation facilities in developing countries is out of order. This leads to the conclusion that, besides technical failures, the planning process in the sanitation sector was ineffective. This ineffectiveness may be attributed to the lack of knowledge of the sanitation planners about the local conditions of the sanitation project. In addition, sustainability of a technology is often approached from a fragmented perspective that often leads to an unsustainable solution. The dissertation is conducted within the framework of the Integrated Water Resources Management (IWRM) Indonesia project. The goal of this work is to contribute to the development of a methodology of a planning tool for sustainable sanitation technology. The tool is designed for sanitation planners in developing countries, where a top-down planning approach is common practice. The proposed tool enables comprehensive sustainability assessments (using the Helmholtz Concept of Sustainability as reference), taking into account local conditions. State of the Science In the planning practice, many sanitation planning tools focus on technology selection. However, it has become evident that the selection criteria for sustainable technologies are not always considered in the tools' framework. In other cases, when the criteria are provided by the tool, there is no clear indication of the conditions to be fulfilled in order to meet these criteria. Specifically, there is no reference to what is meant by sustainable technology in a particular context and how to comprehensively assess the sustainability of different technology options. Research Methodology Developing a planning tool is an empirical process, combining theory and practical experience. Hence, the development process of such a tool requires extensive observations, particularly on the interaction between stakeholders in the sanitation sector as well as between technology and its environment. For this purpose, a case study within the project area was carried out. Pucanganom, a village representing common strategic problems in developing countries (e.g. top-down planning approaches, lack of involvement of beneficiaries in the planning process, lack of sustainability assessments) was finally selected as the case study area. After the in-depth case study, an analytical generalisation was developed to enable the tool's application to a broader context. Results The result of this research is a new tool - the Sustainability-based Sanitation Planning Tool (SusTA). SusTA enables comprehensive sustainability assessment in its five generic steps, namely: (1) analysis of stakeholders and sanitation policy in the region, (2) distance-to-target analysis on sanitation conditions in the region, (3) examination of physical and socio-economic conditions in the project area, (4) contextualisation of the technology assessment process in the project area, and (5) sustainability-oriented technology assessment at the project level. These steps are conducted at two levels of planning - the region and the project area - in order to identify the specific problems and interests which influence the selection of a sanitation system. Each planning step is equipped with tool elements (e.g. set of indicators, household questionnaires, technology assessment matrices) to support the analysis. From the development of SusTA, it can be concluded that four elements are required for an effective and widely applicable sanitation planning tool: sustainability concept, participatory approach, contextualisation framework and modification framework. SusTA provides both a theoretical and a practical basis for assessing the sustainability of sanitation technologies in developing countries. The tool's main advantages for decision makers in these countries are: It is simple and transparent in its steps, does not require vast amounts of data and does not need a sophisticated computer program.}, subject = {sanitation planning, sustainable technology, sustainability assessment}, language = {en} } @article{MehlingSchnabelLondong, author = {Mehling, Simon and Schnabel, Tobias and Londong, J{\"o}rg}, title = {Photocatalytic ozonation in an immersion rotary body reactor for the removal of micro-pollutants from the effluent of wastewater treatment plants}, series = {Water Science \& Technology}, volume = {2022}, journal = {Water Science \& Technology}, number = {volume 85, issue 1}, publisher = {IWA Publishing}, address = {London}, doi = {10.2166/wst.2021.617}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20220209-45865}, pages = {535 -- 548}, abstract = {Carrier-bound titanium dioxide catalysts were used in a photocatalytic ozonation reactor for the degradation of micro-pollutants in real wastewater. A photocatalytic immersion rotary body reactor with a 36-cm disk diameter was used, and was irradiated using UV-A light-emitting diodes. The rotating disks were covered with catalysts based on stainless steel grids coated with titanium dioxide. The dosing of ozone was carried out through the liquid phase via an external enrichment and a supply system transverse to the flow direction. The influence of irradiation power and ozone dose on the degradation rate for photocatalytic ozonation was investigated. In addition, the performance of the individual processes photocatalysis and ozonation were studied. The degradation kinetics of the parent compounds were determined using liquid chromatography tandem mass spectrometry. First-order kinetics were determined for photocatalysis and photocatalytic ozonation. A maximum reaction rate of the reactor was determined, which could be achieved by both photocatalysis and photocatalytic ozonation. At a dosage of 0.4 mg /mg DOC, the maximum reaction rate could be achieved using 75\% of the irradiation power used for sole photocatalysis, allowing increases in the energetic efficiency of photocatalytic wastewater treatment processes. The process of photocatalytic ozonation is suitable to remove a wide spectrum of micro-pollutants from wastewater.}, subject = {Abwasserreinigung}, language = {en} } @misc{Hammerschmidt2005, type = {Master Thesis}, author = {Hammerschmidt, Enrico}, title = {Quantifizierung diffuser Phosphoreintr{\"a}ge in Oberfl{\"a}chengew{\"a}sser am Beispiel des Einzugsgebietes der oberen Rur}, doi = {10.25643/bauhaus-universitaet.618}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-6182}, school = {Bauhaus-Universit{\"a}t Weimar}, year = {2005}, abstract = {Im Rahmen dieser Diplomarbeit werden die diffusen Phosphoreintr{\"a}ge am Beispiel des Einzugsgebietes der oberen Rur bilanziert . Im theoretischen Teil dieser Diplomarbeit werden die Grundlagen f{\"u}r die Darstellung des N{\"a}hrstofftransportes erarbeitet. Dabei erfolgt die Beschreibung der Eintragswege von Phosphor in die Gew{\"a}sser, die Herkunft und Art von Phosphoreintr{\"a}gen sowie die wichtigen Eintragspfade der diffusen Phosphoreintr{\"a}ge. Mit diesen gewonnenen Erkenntnissen ist es m{\"o}glich, den Stofftransport einschließlich der ablaufenden Prozesse mittels mathematischer Gleichungen {\"u}ber die Eintragspfade zu simulieren. Somit gelingt es, die Funktionsweise und die Anwendbarkeit, der zum Einsatz kommenden aktuellen Wasser- und Stofftransportmodelle zur Quantifizierung diffuser Phosphoreintr{\"a}gen zu verstehen. Im praktischen Teil dieser Diplomarbeit werden die diffusen Phosphoreintr{\"a}ge im Einzugsgebiet der oberen Rur unter Hilfenahme der zuvor ermittelten Grundlagen bilanziert. Dabei ist es n{\"o}tig, das Einzugsgebiet zu beschreiben, abzugrenzen und die enthaltenen Gew{\"a}sser zu beleuchten. Weiterhin erfolgte eine Recherche der im Einzugsgebiet vorhandenen Fl{\"a}chennutzungen, um die Bilanzierung mit den aus der Literatur ermittelten Gleichungen und Werten durchf{\"u}hren zu k{\"o}nnen. Das Ergebnis ist eine Phosphorjahresfracht mit der das Einzugsgebiet bewertet werden kann.}, subject = {Erosion}, language = {de} } @misc{Gaberdan, type = {Master Thesis}, author = {Gaberdan, Elisa}, title = {Konzeption und prototypische Implementierung von Simulationsszenarien des Regenwassermanagements zur Entscheidungsunterst{\"u}tzung mit Hilfe von SimCity}, doi = {10.25643/bauhaus-universitaet.2070}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20131104-20700}, school = {Bauhaus-Universit{\"a}t Weimar}, abstract = {F{\"u}r anwendungsbezogene L{\"o}sungsans{\"a}tze im Bereich der Siedlungswasserwirtschaft im urbanen Raum ist es wichtig, die Inhalte komplexer ineinander greifender Systeme zu begreifen. Ein Simulationsspiel kann hilfreich sein, um den Nutzer mit neuen Technologien und M{\"o}glichkeiten der Kombination vertraut zu machen. Aufgrund hoher Anforderungen an Komplexit{\"a}t und Detailliertheit der Modelle ist die Entwicklung eines solchen Spiels teuer und aufw{\"a}ndig. Diese Arbeit untersucht, inwieweit sich das kommerziell zu Unterhaltungszwecken entwickelte Spiel SimCity 5 (Version 2013) nutzen l{\"a}sst bzw. wie es konfiguriert werden muss. Im Speziellen wird dies am Beispiel des naturnahen Regenwassermanagements im urbanen Raum erl{\"a}utert. Die Analyse von SimCity 5 zeigt, dass sich das Spiel durchaus als Werkzeug zur Entscheidungsunterst{\"u}tzung eignet. Die Teilsysteme der Siedlungswasserwirtschaft sind jedoch zu stark vereinfacht, sodass Verbesserungsbedarf besteht. Um Szenarien des naturnahen Regenwassermanagements in das Spiel zu integrieren, wurde im Rahmen der Arbeit das Modell SimRegen entwickelt. Da derzeit keine Schnittstelle zur agentenbasierten Simulationsengine GlassBox freigegeben ist, wurden Teilaspekte des Modells mit Hilfe des agentenbasierten Simulationswerkzeugs NetLogo (Version 5.0.4) implementiert.}, subject = {Regenwassermanagement}, language = {de} } @misc{Fach2005, type = {Master Thesis}, author = {Fach, Susanne}, title = {F{\"a}llung von Magnesium-Ammonium-Phosphat aus Schlachthofabwasser}, doi = {10.25643/bauhaus-universitaet.588}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-5886}, school = {Bauhaus-Universit{\"a}t Weimar}, year = {2005}, abstract = {In dieser Arbeit wird die F{\"a}llung von Magnesium-Ammonium-Phosphaten (MAP) aus Schlachthofabwasser behandelt. Einleitend wird der Schlacht- und Zerlegprozess von Tieren in der Nahrungsmittelindustrie beschrieben und dabei die Stellen des Abwasseranfalls gekennzeichnet. Nachfolgend werden einige chemische Grundlagen zum MAP und dessen Kristallisationsparameter erl{\"a}utert und ausgewertet. Nach Auswertung eigener F{\"a}llungsversuche wird ein Vorschlag f{\"u}r eine technische L{\"o}sung gebracht und dessen Kosten abgesch{\"a}tzt.}, subject = {Kristallisation}, language = {de} } @misc{Bachert2005, type = {Master Thesis}, author = {Bachert, Carsten}, title = {Anaerobe Behandlung von Substrat aus Braunwasser}, doi = {10.25643/bauhaus-universitaet.555}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-5553}, school = {Bauhaus-Universit{\"a}t Weimar}, year = {2005}, abstract = {F{\"u}r die weitgehende Nutzung der enthaltenen N{\"a}hrstoffe in h{\"a}uslichem Abwasser und die Realisierung des Kreislaufgedankens auch in kommunalen Abwassersystemen ist eine Trennung der Abwasserstr{\"o}me, wie sie vielfach bereist in der industriellen Produktion eingesetzt wird, Vorrausetzung. Die getrennte Erfassung und Sammlung sowie die Nutzung bzw. Behandlung der einzelnen Teilstr{\"o}me weicht von den {\"u}blichen Verfahren der bisher praktizierten end-of-pipe-Systeme ab und es gilt nach alternativen Verfahrensm{\"o}glichkeiten zu suchen, um die Ziele eines teilstromorientierten Abwasserkonzeptes zu verwirklichen. Im Rahmen dieser Arbeit wird ein anaerobes mesophiles Behandlungsverfahren f{\"u}r den Teilstrom Braunwasser untersucht. Zu diesem Zweck wurden verschieden Versuche mit Faeces mit unterschiedlichen Wassergehalten und in unterschiedlichen Mischungen von Einsatz des Rohsubstrates bis hin zur Zugabe von Urin, Wasser und/oder Impfschlamm untersucht. W{\"a}hrend der Versuche in temperierten Reaktoren fand eine Aufzeichnung der Gasertr{\"a}ge der einzelnen Ans{\"a}tze, der pH-Werte in ausgew{\"a}hlten Ans{\"a}tzen, der Raumtemperatur und der Substrattemperatur im Reaktor statt. Diese verschiedenen Ans{\"a}tze sind anhand ihrer Zusammensetzung dargestellt und in den gewonnenen Ergebnissen untereinander und mit denen in der Startliteratur angegebenen Werten verglichen und bewertet. Ziel der anaeroben Behandlung war es, ein stabilisiertes Substrat aus der anaeroben Stufe zu erhalten. Aus den gewonnenen Ergebnissen wird ein Verfahrensvorschlag f{\"u}r eine anaerobe Stabilisierung gemacht.}, subject = {Obligat anaerobe Bakterien}, language = {de} } @article{AicherBoermelLondongetal., author = {Aicher, Andreas and B{\"o}rmel, Melanie and Londong, J{\"o}rg and Beier, Silvio}, title = {Vertical green system for gray water treatment: Analysis of the VertiKKA-module in a field test}, series = {Frontiers in Environmental Science}, volume = {2022}, journal = {Frontiers in Environmental Science}, number = {Volume 10 (2022), article 976005}, publisher = {Frontiers Media}, address = {Lausanne}, doi = {10.3389/fenvs.2022.976005}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20230124-48840}, pages = {1 -- 7}, abstract = {This work presents a modular Vertical Green System (VGS) for gray water treatment, developed at the Bauhaus-Universit{\"a}t Weimar. The concept was transformed into a field study with four modules built and tested with synthetic gray water. Each module set contains a small and larger module with the same treatment substrate and was fed hourly. A combination of lightweight structural material and biochar of agricultural residues and wood chips was used as the treatment substrate. In this article, we present the first 18 weeks of operation. Regarding the treatment efficiency, the parameters chemical oxygen demand (COD), total phosphorous (TP), ortho-phosphate (ortho-P), total bound nitrogen (TNb), ammonium nitrogen (NH4-N), and nitrate nitrogen (NO3-N) were analyzed and are presented in this work. The results of the modules with agricultural residues are promising. Up to 92\% COD reduction is stated in the data. The phosphate and nitrogen fractions are reduced significantly in these modules. By contrast, the modules with wood chips reduce only 67\% of the incoming COD and respectively less regarding phosphates and the nitrogen fraction.}, subject = {Grauwasser}, language = {en} }