Sewage Treatment Tenders

Details: The subject of the planning is the Luckenwalde sewage treatment plant, in particular the biological/chemical treatment stage. Planning solutions must be found for the following key problems: The biological stage is currently strictly structured as two-lane systems, with no mutual redundancy. For example, aeration tank (bb) 1 cannot be operated together with secondary clarifier (nkb) 2 or nkb 1 and nkb 2. The sludge from both bb lines is currently kept separate and there is no mixing. This severely limits possible operating conditions. In particular, if one tank fails, the entire line fails. The sludge properties can develop very differently in the two lines, which can lead to operational problems. The tanks are not hydraulically separated, which means that the water level upstream in the bb and in the inlet distributor structure is influenced by the water level in the nkb. The return sludge pumps are also not hydraulically separated, so that the pump output directly influences the water level in the Nkb. The basins and structures have little freeboard, there are practically no hydraulic reserves. The economical construction method meant that with the existing building fabric, a hydraulic separation of the basins and structures is not possible while maintaining the design inflow. Bb and Nkb are each connected by submerged outgoing and incoming short pipes. Therefore, it is currently not possible to add P-precipitant to the Bb outlet (preferred recommended dosing point - see Dwa M 206). Machinery and equipment are over 25 years old, the building fabric is in need of renovation. In particular, the inlet distribution shaft on the west side of the building is in dire need of renovation on the concrete side and is to be replaced. From a process engineering point of view, cross-redundancy of the tanks and merging of the flows after each tank (mixing and re-dividing) would be recommended in order to make the operation safer and more stable.