The spatial distribution of confining layers within a system of two aquifers strongly affects the hydraulics and sensitivity to pollution. The test site is located close to a well field. Wells are switched with short intervals and hydraulic heads are recorded in several observation wells. Because the absolute levels of simulated hydraulic heads do not always coincide with the measurements, the model is calibrated with short term head variations. The characteristic shape of the hydraulic heads at each observation wells contains sensitive information about the structure of the aquifer. A numerical technique is developed which enables to simulate the spatial distribution of the confining layer. The method comprises the use of pilot points and regularisation technique. Cross validation is carried out in order to show the results are physically based. The method is shown to provide significant results even under non optimal conditions.

The city of Berlin is using bank filtered surface water and artificially recharged water for drinking water production. As far as some hydrological trends and development of anthropogenic pollutants may threat the future of the ground water resource in Berlin, it is important to measure the capacity of ground filtration to answer to such developments, and to secure the use of this systems through the development of the most appropriate practices and the related technologies. This was an obvious reason to initiate a multidisciplinary cooperation project at the Berlin Centre of Competence with the topic "bank filtration and artificial recharge" named Natural and Artificial Systems for Recharge and Infiltration (NASRI). It will focus, for example on questions of the emergence and removal of pharmaceutical residues during bank filtration. The fate and the destination of other specific trace substances as well as of bacteria and viruses are other objectives of the research programme (KWB 2002).

Eine MBR-Laboranlage (210L) wurde mit zwei verschiedenen Reaktor-konfigurationen zur vermehrten biologischen PElimination (Bio-P) mit kommunalem Abwasser betrieben. Die beiden Reaktorkonfigurationen zeichneten sich neben einer vorgeschalteten anaeroben Zone für den Bio-P Prozess durch eine vorgeschaltete Denitrifikation bzw. eine nachgeschaltete Denitrifikation aus. Beide Reaktor-konfigurationen wurden bei einem Schlammalter von 15 Tagen mit vorgesiebtem (1mm) Rohwasser parallel zu einer konventionellen Kläranlage betrieben. Für Phosphor wurden sehr niedrige und stabile Ablaufkonzentrationen von 0,05-0,15 mgP/L mit beiden Konfigurationen erreicht. Die Phosphorgehalte der Schlämme lagen bei 2,4-3% P/TS. Während mit der vorgeschalteten Denitrifikation erwartete Ergebnisse von 86-90% Stickstoffentfernung erzielt wurden, erreichte die nachgeschaltete Denitrifikation eine unerwartet hohe N-Elimination von bis zu 96% (ohne zusätzliche C-Quelle). Eine Betriebsphase mit Phosphoraufstockung des Zulaufes (~40 mgP/L) führte bei einer Elimination von 20-25 mgP/L zu P-Gehalten im Schlamm von 67%P/TS. Neben dem Bio-P-Mechanismus waren hier jedoch auch Fällungs- und Adsorptionsmechanismen für die P-Aufnahme relevant.

Enhanced biological phosphorous (Bio-P) removal process was adapted to membrane bioreactor(MBR). One bench-scale pilot plant (BSP, 200-250L) and two medium-scale pilot plants (2//MSP,1000-3000L each) were operated under several configurations, including pre-denitrification and post-denitrification without addition of carbon source, and two solid retention times (SRT) of 15 and 26d, inparallel to the full-scale Bio-P removal activated sludge plant of Berlin-Ruhleben (12-18d SRT). Thetrials showed that efficient Bio-P removal can be achieved with MBR systems, in both pre- and post-denitrification configurations. Bio-P dynamics could be clearly demonstrated through batch-tests, online measurements, profile analyses, P-spiking trials, and mass balances. High P-removalperformances were achieved even with high SRT of 26d (around 9mgP/L was removed withP/TS~2.6%). Under similar operation conditions of sludge age and mass organic load, the MBRsystem achieved slightly higher P-removal than the conventional technology. This was due to therejection of particles and colloids through the microfiltration membrane. When spiking with phosphate,high Bio-P removal of up to 35-40mg/L could be achieved without addition of external carbon source,and P/TS stabilised around 7.5%.

The occurrence and fate of pharmaceutically active compounds (PhACs) in the aquatic environment has been recognized as one of the emerging issues in environmental chemistry. In some investigations carried out in Austria, Brazil, Canada, Croatia, England, Germany, Greece, Italy, Spain, Switzerland, The Netherlands, and the U.S., more than 80 compounds, pharmaceuticals and several drug metabolites, have been detected in the aquatic environment. Several PhACs from various prescription classes have been found at concentrations up to the µg/l-level in sewage influent and effluent samples and also in several surface waters located downstream from municipal sewage treatment plants (STPs). The studies show that some PhACs originating from human therapy are not eliminated completely in the municipal STPs and are, thus, discharged as contaminants into the receiving waters. Under recharge conditions, polar PhACs such as clofibric acid, carbamazepine, primidone or iodinated contrast agents can leach through the subsoil and have also been detected in several groundwater samples in Germany. Positive findings of PhACs have, however, also been reported in groundwater contaminated by landfill leachates or manufacturing residues. To date, only in a few cases PhACs have also been detected at trace-levels in drinking water samples.