This work was carried out within the framework of the project OPTIWELLS at the Kompetenzzentrum Wasser Berlin (KWB), a non-profit network society for water research and science transfer. The project addresses the modelling of a well field in order to minimise its energy demand. The first phase of the project is a feasibility study to identify the optimization possibilities of the energy demand. The first part of the study concerns the design and testing of a hydraulic model. At the beginning it was implemented on MS Excel and after with the help of Epanet, an opensource software. Data from the operator and manufacturers as well as measured data, gained during a site audit, were used to calibrate the model. Goals were to understand how the well field was working and to identify the energy demand drivers. The second part of the study concerned the choice and the implementation of scenarios with different operational conditions for the well field. Scenarios were focused on two aspects: the change of boundary conditions and the study of possible investments. A cost comparative assessment was carried out to estimate the payback times of the investigated scenarios. Results and according recommendations were communicated to the well field manager.

In order to meet the requirements of the European framework directive on water, authored by the European parliament, measures have to be taken to enhance the situation of the bodies of water in Berlin. The discharge of treated wastewater is an important source of phosphor into the bodies of water of Berlin. The OXERAM project investigates different possible technologies to decrease these entries of phosphor and the conditional growth of algae. Pilot plants for these technologies are being operated at Sewage Treatment Plant Ruhleben (STP Ruhleben). Installed are a microsieve plant and two membrane plants. In previous tests, it was possible to proof the functionality of the microsieve plant under static influent flow and volume proportional chemical dosing. Effluent concentrations of < 80 µg/L were reliably achieved. The goal of this thesis is to evaluate the functionality of the pilot plant under dynamic operating conditions and load proportional chemical dosing. Therefore several tests were conducted. In a first step the pilot plant was operated with an artificial daily flow pattern, which was calculated regarding the daily flow variations in the influent of the STP Ruhleben. Tests under volume proportional dosing, and under load proportional chemical dosing, were conducted. The dosing of the coagulant was thereby varied according to the ortho phosphate concentration in the influent of the pilot. In a third step the influent flow was directly correlated to the influent flow of STP Ruhleben, in combination with load proportional dosing. During all conducted tests, sufficiently low total phosphorus concentrations in the effluent of the pilot plant could be achieved. By using load proportional dosing, savings of 11 % for the coagulant and 14 % for the polymer could be achieved. In addition several tests concerning the optimization of the whole process were conducted e.g. different reaction times for the flocculation and different polymer concentrations were tested. At the end an estimation of the operating costs for a microsieve plant of the size that would be required for the STP Ruhleben was made. Thereby the costs for Energy, Coagulant and Polymer and repair/ maintenance were discovered as main parts of the operating costs. The specific operating costs would be ca. 3.1 Cent/m³. To be able to compare the investigated technology with the other processes further tests of the pilot plant in combination with a UV plant as disinfection step of the effluent water from the microsieve have to be conducted.

This paper is one of the results, developed within the project OXERAM II by the Kompetenzzentrum Wasser Berlin. A pilot plant, equipped with a full (microfiltration) Berlin/Ruhleben. During the is operated for advanced wastewater project, different scale monolithic ceramic membrane treatment at WWTP pre-treatments, namely coagulation and the combination of coagulation and ozonation are applied. Multi-filtration trials in dead-end mode and constant flux operation are performed for over 6 months, with varying operational parameters like flux, time of filtration, dosages of coagulant and ozone. Operational behaviour is evaluated through the evolution of trans-membrane pressure via time. Also total and irreversible fouling rates are calculated showing benefits within the combined pre-treatment, regarding membrane fouling and stable operation at high recoveries (98 %). The application of 15 mgO3 · L-1, respectively a specific ozone dosage from 1.0 to 1.4 mgO3 · (mgDOC)-1 leads to a total fouling rate reduction of 75 %. LC-OCD analysis is furthermore used for a more detailed view on changes in DOC, especially biopolymers. Sampling of the pilot plants influent and effluent water is additionally used for the evaluation of treatment efficiency, e.g. disinfection and in particular phosphorous, where emissions are reduced to 20 ± 5 µg P · L-1 in accordance with the European Water Framework Directive (Directive 2000/60/EC).

Im Rahmen der Arbeit soll basierend auf einem gemeinsam mit den Projektpartnern entwickelten Probenahme-Protokoll, siehe Tabelle 11, eine relationale Datenbank zur Erfassung aller Proben und Versuchsergebnisse erstellt werden. Da bis zum jetzigen Zeitpunkt noch keine Datenbank existiert, die in der Lage ist alle Daten der Projektpartner zusammenzuführen, war ein Austausch nur bedingt möglich. Eine Zusammenführung aller Daten für die statistische Auswertung ist somit fast nicht zu verwirklichen. Nur mit Hilfe der Datenbank ist ein einfacher Austausch sowie eine gesicherte Datenzusammenführung möglich. Das Praktikum beinhaltet die Mitarbeit an der Konzeption einer solchen Datenbank sowie die selbständige Umsetzung in Microsoft Access.

Im Sommer 2011 kam es in Berlin zu überdurchschnittlichen Regenfällen von mehr als 200 Litern je Quadratmeter. Die Vervierfachung des durchschnittlichen Monatsniederschlages führte neben einer Erhöhung des Wasserpegels umliegender Gewässer zu einer Sättigung des Bodens mit Wasser. Es bestand die Annahme, dass durch die beschleunigte Versickerung oberflächennahen Wassers ein unerwünscht starker mikrobieller Eintrag in das Rohwasser von einzelnen Brunnen der BWB stattfand. Entscheidend bei der Betrachtung des vertikalen Transportes von pathogenen Keimen im Sickerwasser im direkten Brunnenumfeld war die Frage der minimalen Fließzeit bis zum Erreichen der Filteroberkante (FOK) des Brunnens. Ziel der vorliegenden Arbeit war die Untersuchung von unerwünschten Wasserzutritten entlang der Ausbaumaterialien eines Vertikalfilterbrunnens mit Tonsperre auf dem Gelände des WW Jungfernheide der BWB. Anhand von Feldversuchen, insbesondere durch den Markierungsversuch mit dem löslichen fluoreszierenden Farbtracer Uranin, sollte der ausgewählte Testbrunnen auf mögliche Kurzschlüsse an Abdichtungsvorrichtungen überprüft werden. Die Quantifizierung der Fließzeit und der Vergleich von Brunnen wurde nicht angestrebt. Es wurde lediglich bewertet, ob die Fließzeit eher im Bereich weniger Tage (Schutzfunktion fehlt) oder sich im Bereich mehrerer Wochen (Schutzfunktion vorhanden) befand. In Vorbereitung auf den Markierungsversuch mit dem Fluoreszenzfarbstoff Uranin wurden zur Bestimmung der potentiellen Versickerungsleistung innerhalb der Brunnenstube und im direkten Brunnenumfeld gezielte Vorversuche vorgenommen. Dabei wurden zum einen innerhalb der Brunnenstube potentielle Undichtigkeiten an den Brunnenkomponenten überprüft, zum anderen mit Hilfe eines provisorisch errichteten Ringinfiltrometers außerhalb des Brunnenbauwerks das Infiltrationsverhalten der Grundwasserüberdeckung erfasst. Unter Berücksichtigung einer berechneten minimal kritischen Infiltrationszeit wurde durch die Simulation eines kontinuierlichen Starkregenereignisses innerhalb von 10 Tagen der Markierungsversuch durchgeführt. Aus den gewonnenen Messergebnissen des Markierungsversuches konnte in erster Linie geschlussfolgert werden, dass es im Bereich entlang des Ausbaumaterials des Testbrunnens keine Umläufigkeiten an der Ringraumverfüllung gab und folglich eine intakte Schutzfunktion der Abdichtungsvorrichtung gegenüber schnell infiltrierendem Wasser vorhanden ist. Auch innerhalb der Brunnenstube konnte infolge der Vorversuche eine Dichtigkeit aller Komponenten nachgewiesen werden. Aufgrund einer unabsehbaren technisch bedingten Messunterbrechung während des Markierungsversuches wurde vereinbart einen zweiten Markierungsversuch zur Überprüfung der Richtigkeit durchzuführen. Da es sich bei den absolvierten Versuchen noch um unerprobte Verfahren zum phänomenologischen Nachweis von Kurzschlüssen an Vertikalfilterbrunnen der BWB handelt, ist bei einer entsprechenden Verbesserung der Methodik sowie in Betracht der schnellen und kostengünstigen Durchführung eine weitere Anwendung an Brunnen der BWB empfehlenswert.

Risk-based management approaches are more and more used in the water sector and are promoted by the WHO. As a first step towards an overall risk-based management approach of the agricultural wastewater reuse concept of Braunschweig this thesis conducts quantitative microbial risk assessment (QMRA) and quantitative chemical risk assessment (QCRA) of heavy metals. Scenarios for microbial risks are conducted for fieldworkers, nearby residents and children ingesting soil using a 1000 trial Monte Carlo Simulation. As a tolerable value of risk an additional disease burden of 1 µDALY is set following the current WHO guidelines. For heavy metals impacts on the terrestrial and aquatic ecosystems as well as on human health are assessed using the methods outlined in the European Union Technical Guidance Document on Risk Assessment (TGD). Concerning microbial risks risk-based targets are set in terms of additional required pathogen reduction in the STP Steinhof. Based on the model results an additional reduction of 1.5log units is derived for viruses, for which the highest annual risks of infection per person per year (pppy) is calculated in all scenarios. Concerning heavy metals the model indicates an increasing tendency of soil concentrations over time and identifies Cd as the only metal which is currently of concern. Risk reduction measures should be considered for this metal. Recommendations are given concerning necessary validation and additional monitoring for eliminating uncertainties within the model.

Zum Klärwerk Berlin-Münchehofe, in dem Phosphor mittels chemischer Fällung entfernt wird und zum Klärwerk Berlin-Waßmannsdorf, in dem eine Bio-P-Elimination eingesetzt wird, wurden eine vergleichende Ökobilanz und ein Wirtschaftlichkeitsvergleich durchgeführt. In die Untersuchung einbezogen wurde die Phosphorrückgewinnung mit dem MAP-Verfahren, die im Klärwerk Waßmannsdorf zur Anwendung kommt. Ziel der Arbeit ist es, anhand der Referenzsysteme das aus ökologischer und ökonomischer Sicht vorzuziehende Verfahren der Phosphorentfernung zu bestimmen. Es wurde eine statische Modellierung der einzelnen Prozesse der betrachteten Klärwerke anhand einer großen Datengrundlage durchgeführt. In der Wirkungsabschätzung wurden für verschiedene Wirkungskategorien wie Treibhauspotential oder Eutrophierungspotential die negativen Auswirkungen der Klärwerke auf die Umwelt ermittelt. Außerdem wurden Investitions- und Betriebskosten der Klärwerke ermittelt und gegenübergestellt. Es zeigt sich, dass das Bio-P-Verfahren in Kombination mit der MAP-Rückgewinnung geringere negative Umweltwirkungen verursacht als das Verfahren der chemischen P-Fällung mit der Herstellung konventionellen Mineraldüngers. Es ist für die Umwelt das verträglichere Verfahren. Die Investitionskosten des KW Waßmannsdorf sind höher als die des KW Münchehofe. Die Betriebskosten sind vergleichbar.

The capacity of drinking water abstraction wells, which is the yield for a given drawdown of the water level, is often decreasing after a certain time of operation. This well ageing can be caused in carbonate aquifers by a chemical process : calcite precipitation. Using an hydrogeochemical model developped during the internship, the quantity of precipitated calcite and the time required to fill up the bore are estimated. It is then showed that carbonate precipitation is enhanced by chemical and physical parameters (hydrogenocarbonate concentrations, temperature) as well as the operating of the well (pumping and resting).

In the future, advanced phosphorus removal will be necessary in many WWTP in order to meet the demands of the European water framework directive. The project OXERAM deals with the comparison of different technologies with regard to their efficiency and applicability in tertiary treatment. In the course of the project membrane and microsieve filtration are tested in pilot scale at the Ruhleben STP. In this thesis the optimization of coagulation and flocculation prior to microsieve filtration for advanced phosphorus removal (< 80 µg/L TP; total phosphorus) was investigated. For the optimization of the coagulation/ flocculation several test series were conducted with the aid of jar test and the mircosieve pilot plant. A direct comparison of jar tests and the pilot plant showed that jar tests are an appropriate method to predict the approximate outcome of optimization steps (e.g. variation of chemical doses) in the pilot plant. The pilot trials were able to demonstrate that the microsieve technology (10 µm pore size) in combination with chemical pre-treatment of 0.036 - 0.179 mmol/L coagulant (Fe or Al) and 2 mg/L cationic polymer could easily achieve good and reliable TP removal. The phosphorus removal was comparable to dual media filtration (< 80 µg/L TP) and partly even to membrane filtration (< 50 µg/L TP). The reduction of the residual coagulant contents in the filtrate was identified as the main challenge of this technology. High iron contents of about 1 mg/L were accompanied by floc formation behind the mircosieve in filtrate tank and pipe. In a microsieve the formed flocs have to endure high shear forces. Thus, the so-called post-flocculation was most probably caused by re-flocculation of floc fragments. Very low phosphorus values < 50 µg/L were possible at high metal dosing. But the higher suspended solid load reduced the filtration capacity of the microsieve. Coagulation with polyalumium chloride (PACl) produced better effluent quality compared to FeCl3 as less suspended solids and less residual coagulant were found in the microsieve effluent. Furthermore, the transmission of UV radiation through the water was improved from 47 up to 66 % by using PACl which is favorable if a downstream UV disinfection is considered. When using FeCl3 the transmission was not improved or even reduced. Due to the influence on the performance of the microsieve cationic polymers were preferred to anionic polymers. However, the tested anionic polymer proved to be not applicable in the given process configuration due to very low filtrate flows. When cationic polymer was applied the polymer dose had a high impact on the particle removal and moreover on the contents of phosphorus and coagulant residuals in the effluent. In most cases 2 mg/L polymer was necessary. In total, the microsieve technology in combination with chemical pre-treatment is a suitable option for advanced phosphorus removal. Through a dynamic adjustment of the chemical dosing to the influent water quality (e.g. ortho phosphate and turbidity online measurement) and the choice of polymer the process could be optimized in the future with regard to efficient chemical application.