Erfahrungen aus dem Betrieb einer Membranbelebung mit diskontinuierlichem Schlammabzug werden vorgestellt. Das Ziel ist, den Einfluss der Betriebsbedingungen auf Fouling und den Abbau extrazellulärer polymerer Substanzen zu bestimmen sowie mit bekannten Zusammenhängen aus Anlagen mit kontinuierlichem Abzug zu vergleichen.

Since the 1970s, we have known about real-time control of urban drainage systems. However, global real-time control strategies still show a lack of implementation for large drainage systems of high complexity. In Berlin, Germany, a city of 3.5 million inhabitants covering an area of around 900 km2, the demand for enhanced protection of the environment and growing economic pressure have led to an increasing application of control assets and concepts within the sewage system. In the framework of the project "Integrated Sewage Management", the possibilities of a global and integrated control strategy for the Berlin system are examined. The paper is focused on the historical concept and design of the sewerage and the further improvement towards an environment-oriented system that builds the basis for today's considerations. The operational method and functionality of local regulators that have already been implemented are described. Further-more, the model-based methodology for the analysis of the system and the development of global control concepts, as well as the results of system analysis, are stated. On the basis of model simulations, it is shown that a global coordination of pump stations can lead to a reduction of sewer overflows, and consequently to an enhanced water protection.

River bank or slow sand filtration is a major procedure for processing surface water to drinking water in central europe. In order to model the performance of river bank and slow sand filtration plants, we are studying the different mechanisms by which the elimination of pathogens is realized. An important question concerning the mode of action of slow sand filters and river bank filtration units is the role of the colmation layer or “schmutzdecke” on the elimination of human pathogens. The schmutzdecke is an organic layer which develops at the surface of the sand filter short after the onset of operation. We have inoculated a pilot plant for slow sand filtration with coliphages and determined their rate of breakthrough and their final elimination. In the first experiment, with a colmation layer still missing, the breakthrough of the coliphages in the 80 cm mighty sandy bed amounted to ca. 40 %. In contrast, less than 1 % of coliphages escaped from the filter as the same experiment was repeated two months later, when a substantial colmation layer had developed. Our preliminary conclusions are that the colmation layer is extremely efficient in eliminating of viruses.

Simulation tools help develop an integrated approach for Berlin’s combined sewage system in which sewage overflows pose risk to groundwater and surface water quality

Die Berliner Wasserbetriebe haben zusammen mit Veolia Water im Rahmen des Kompetenzzentrums Wasser Berlin ein Pilotprojekt zu neuen Sanitärkonzepten begonnen. Zur Ermittlung der zu erprobenden neuen, nachhaltigen Sanitärkonzepte wurde eine Vorstudie durchgeführt. Diese Studie beinhaltet u.a. einen Kostenvergleich zwischen zwei neuen Sanitärkonzepten mit Schwerkraft- und Vakuumseparationstoiletten und dem konventionellen System. Es konnte gezeigt werden, dass die neuen Sanitärkonzepte, abhängig von den Rahmenbedingungen, Kostenvorteile haben. Dies war eine weitere Motivation, ein Pilotprojekt zur Erprobung der neuen Sanitärkonzepte unter realistischen Bedingungen in Berlin/Brandenburg durchzuführen. Der Betrieb des Sanitärkonzepts mit Schwerkrafttrenntoiletten hat im Sommer 2003 begonnen.

Bank filtration and artificial ground water recharge are important, effective, and cheap techniques for surface water treatment and removal of microbes, as well as inorganic, and some organic, contaminants. Nevertheless, physical, chemical, and biological processes of the removal of impurities are not understood sufficiently. A research project titled Natural and Artificial Systems for Recharge and Infiltration attempts to provide more clarity in the processes affecting the removal of these contaminants. The project focuses on the fate and transport of selected emerging contaminants during bank filtration at two transects in Berlin, Germany. Several detections of pharmaceutically active compounds (PhACs) in ground water samples from bank filtration sites in Germany led to furthering research on the removal of these compounds during bank filtration. In this study, six PhACs including the analgesic drugs diclofenac and propyphenazone, the antiepileptic drugs carbamazepine and primidone, and the drug metabolites clofibric acid and 1-acetyl–1-methyl–2-dimethyloxamoyl– 2-phenylhydrazide were found to leach from the contaminated streams and lakes into the ground water. These compounds were also detected at low concentrations in receiving public supply wells. Bank filtration either decreased the concentrations by dilution (e.g., for carbamazepine and primidone) and partial removal (e.g., for diclofenac), or totally removed PhACs (e.g., bezafibrate, indomethacine, antibiotics, and estrogens). Several PhACs, such as carbamazepine and especially primidone, were readily transported during bank filtration. They are thought to be good indicators for evaluating whether surface water is impacted by contamination from municipal sewage effluent or whether contamination associated with sewage effluent can be transported into ground water at ground water recharge sites.

The effect of oscillating pumping regimes at the bank filtration site in Berlin Tegel is examined via a scenario based modelling study. Several scenarios for the pumping regimes are calculated, some adopted from the operation of the plant by the Berlin Water Works (BWB), some hypothetical with a regular oscillating regime. Two of these are presented here. A horizontal 2D model of the lower aquifer is set-up, in which the third type boundary condition is used to mimic the influence of an irregularly shaped till layer, overlying the main aquifer. Model results in form of flowpaths are presented for several pumping scenarios. They reveal that there is a substantial influence of the pumping regime on the flowpaths in the vicinity of the well gallery, while in the far field, including the bank of the surface water body (here: Lake Tegel) the oscillating effect is rather small. It depends very much on the infiltration position on the bank, whether traveltime through the aquifer changes as effect of oscillating pumping regime.

Induced by well abstraction, surface water infiltrates into Berlin aquifers and is used for drinking water production. A major advantage of bank filtration is the capability of the subsurface to remove contaminants and save natural groundwater resources. Since a large proportion of the surface water in Berlin originates from treated effluents released by wastewater treatment plants, certain wastewater residues can be traced into the groundwater. A powerful tool to characterise bank filtration systems is the use of wastewater indicators and additional environmental tracers to estimate flow velocities and proportions of bank filtrate in the abstraction wells prior to reactive transport evaluations. Examples for tracer applications at the Berlin system are introduced in this paper. In addition, an overview on results of various studies conducted on contaminant transport and removal during underground passage of the bank filtrate in Berlin is given.