The complete utilization of the capacities of a complex sewage system, consisting of networks, storage and control assets, pressurized network and waste water treatment plants, especially for storm weather events is a central task to minimize the pollutant load discharged in the receiving waters. With the objective of a minimization of water pollution load within the urban area of Berlin (Germany) the project “Integrated Sewage Management” has been launched in 2000. The central points of this project are the application of integrated simulation tools for the examination of different management scenarios and after that the definition and installation of an integrated operation concept for the system. This paper presents a first phase of the project, the modelling of the combined sewerage system of a pilot catchment area in the center of Berlin, results of simulation mainly focused on the real time control potential of the system and first steps of transferring this into an operation concept.

The complete utilization of the capacities of a complex sewage system, consisting of networks, storage and control assets, pressurized network and waste water treatment plants, especially for storm weather events is a central task to minimize the pollutant load discharged to receiving waters. With the objective of a minimization of water pollution load within the urban area of Berlin the project “Integrated Sewage Management” has been launched in 2000. The central points of this project are the application of integrated simulation tools for the examination of different management scenarios followed by the definition and installation of an integrated operation concept for the system. Special attention is turned to the combined sewage system where sewer overflows represent a potential risk for river pollution. Real time control of local regulators and thereby the activation of additional storage capacity within the network can lead to an optimization of the overall system. The paper is focusing on the methodology of model building to examine the sewage system and its operation management including geometric setup, measurement campaigns, calibration and validation. Moreover, the application of the model to evaluate the use of a mobile weir within the sewerage and its real time control is stated.

The present report characterizes the field sites Lake Tegel and Lake Wannsee as well as the artificial recharge site GWA Tegel in terms of their clogging layer, sedimentary, hydraulic and hydrochemical properties. As a result, a solid basis for the interpretation of specific compounds evaluated within NASRI and for subsequent modeling and quantification of the data is given. Major problems or difficulties where identified, in order to focus investigations on aspects not fully understood to date in the next project phase. The combination of different tracers enables the interpretation of the flow regime. With the help of T/He analysis, ages of different water bodies can be estimated. The analysis of tracer showing distinct seasonal variations is used to estimate travel times while water constituents which are either mainly present in the bank filtrate or the background water are used for mixing calculations. The proportions of treated wastewater in the surface water were estimated in front of the transects. The surface water composition varies largely both in time and space, which is a problem at Wannsee, where the surface water sampling point is not representative for the bank filtration input. Estimates for travel times of the bank filtrate to individual observation and production wells are given and vary between days and several months. The production wells are a mixture of bank filtrate and water from inland of the wells and deeper aquifers, proportions of bank filtrate are given where possible to differentiate between contaminant removal and dilution. They vary between < 20 and > 80 %. The new observation wells enable a vertical differentiation of the infiltrate. It becomes clear that at Tegel and Wannsee, there is a strong vertical succession towards larger proportions of considerably older bank filtrate with depth. At the Wannsee transect, the observation wells deeper than the lake do not reflect the surface water signal at all. It will be important to combine the new information with hydraulic information of existing flow models (mainly of the IGB “model” group). The evaluation of the redox conditions shows that redox successions proceed with depth rather than (only) in flow direction. In addition, the redox zoning (as characterised by the appearance or disappearance of redox sensitive species) is very transient. The zones are much wider in winter than in summer, in particular at the artificial recharge site GWA Tegel, probably due to temperature effects. This poses a challenge for the desired modelling and the interpretation of data from redoxsensitive substances.

For advanced phosphorus (P) removal sorption processes were studied in benchscale to offer a post-treatment step in addition to the relatively unknown biological Premoval in membrane bioreactors (MBR) for decentralized wastewater treatment. First three commercially available sorbents, granulated ferric hydroxide GFH, activated alumina ATE and an iron hydroxide/oxide FER, were screened for their affinity and capacity in removing phosphorus from MBR filtrates. GFH features the highest loading and affinity for P and additionally removes organics followed by ATE. For example, in determination of isotherms at a P-equilibrium concentration of 0.5 mg/L the loading on GFH amounts to 20 mg/g, on ATE to 9 mg/g and on FER only to 3.8 mg/g. Very early FER was excluded from the trials due to its low capacity and desorption of bonding agents leading to an increase instead of a removal of dissolved organic carbon. Different influencing parameters were studied in the P-sorption on GFH and ATE. Lowering the pH from 8 to 5 improved the P-sorption only by 30 %. A pH-adjustment for optimization is not recommendable due to the strong buffering of MBR filtrates by the carbonate/hydrogen carbonate system. A decrease in temperature had no effect in P-sorption on GFH at low initial P-concentrations, while the loading on ATE was reduced compared to room temperature. Therefore, an improvement is not expected by an outdoor operation of sorption filters. No main influencing competition by other organic or inorganic compounds could be determined on P-sorption in MBR filtrates. Due to the negatively charged sorbent surfaces the specifically sorbing phosphorus has an decisive advantage over unspecifically sorbed anions like chloride and sulfate. In time depending experiments lacking of calcium had a kinetic effect on P-sorption, but calcium is present in sufficient amount for P-sorption in MBR filtrates. In sorption filter tests using bed volumes (BV) around 90 mL a limit value of 50 µg/L P is reached in the effluent at 8,000 bed volumes for GFH and 4,000 for ATE sing a influent concentration of 0.3 mg/L P. At a lower influent concentration of 0.1 mg/L P the breakthrough at the limit can be extended to above 15,000 BV for GFH and 8,000 for ATE. While GFH affords a contact time of 10 min, around 30 min contact time is needed in sorption filters filled with ATE to achieve a late breakthrough. A partial regeneration and P-reloading on GFH and ATE can be achieved by using 0.6 M NaOH in differential recirculating flow reactors. But for several reasons the regeneration can not be transferred to sorption filters directly. Due to the long operation time of sorption filters at low influent concentrations = 0.3 mg/L P the regeneration and reloading could not be studied in sorption filters here. Therefore, the cost estimations could only be based on a few scenarios. Using ATE or GFH, total costs are in the range of 8 - 30 Cents/m³ depending on the possibility of regeneration and reuse of sorbents. If no regeneration can be achieved, an application of ATE would be favoured due to its lower price. Based on an effective regeneration a sorption technique using GFH would be preferable. This is emphasized by the high affinity of GFH for P, which is especially required at low effluent P-concentrations from MBR. As an outlook it is recommended to verify the sorption performance and to study the breakthrough behavior in a pilot scale (H = 1 m, d = 300 mm). Furthermore, the investigations on regeneration have to be intensified and conducted in sorption filters to assess influencing parameters like the effect of the previous sorption time on regeneration, the regeneration time and concentration of regenerate. The frequency of regeneration and reuse of sorbent until disposal can only be stated by future longterm trials in sorption filters. Due to the low volume flow rate in the small studied sorption filter, which showed no pressure drop during the trials, it is hard to predict if a backwashing is necessary in larger scale. Whether the particle-free MBR filtrate is advantageous for filter operation, in a long-term scale microorganism growth might occur and result in clogging of sorption filters. In this view a regeneration seems to be advantageous and might replace both backwashing and disinfection rinsing.

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 European Water Framework Directive of 1991, which aim is to limit the discharge of urban rainwater, constrains the cities to improve their sewerage system in order to face such events. The combined sewer overflows are a very sensitive theme in Berlin because of the city’s drink water supply system. The Integrated Sewage Management project, materialized within the Berlin Water Competence Center, aims to optimize the network thanks to hydraulic and pollution modelling. The first step of this study is to model a pilot catchment’s area, thanks to the Hydroworks DM software. Beyond the network constitution, a measurement campaign is realized to calibrate the model, for hydraulic as well as for pollution processes. This has to be done for both dry and rain weather. A first calibration is made possible by the results of dry weather measurements. The analysis of rain weather measurements will allow the validation of the model to be done, and its transposition to the other Berlin catchment’s areas.