Large waste water treatment plant Ataköy
in Istanbul
Istanbul, the metropolis that is home to millions of people, is becoming cleaner and more environmentally friendly, and is coming into line with European standards. Following an international tender, WTE Wassertechnik GmbH, Essen, was awarded the contract in 2007 to build the waste water treatment plant for the Ataköy district in the capital of Turkey, Istanbul. The client for this project is the water and effluent association of Istanbul (ISKI).
Contents
- One of the largest waste water treatment plants in Turkey
- Producing biogas from sewage sludge
- Low specific energy consumption due to the decanters used
- Local maintenance, repairs and service
- Westfalia Separator Sanayi ve Ticaret Ltd. Sti.
High-ranking political representatives are already describing this environmental project, with an investment volume of more than EUR 100 million, as the key to avoiding further contamination of the Mediterranean. This is because the effluent from several districts of Istanbul can now be treated extensively. With dewatering and thickening technology from the GEA Westfalia Separator Group: in total, 16 decanters are used for thickening surplus activated sludge and primary sludge, and for dewatering digested sludge.
One of the largest waste water treatment plants in Turkey
Together with its local construction partners, WTE Wassertechnik completed the Ataköy waste water treatment plant in the similarly named district at the airport in the summer of 2010. In addition to turnkey construction of the new plant, the project also comprised operations management for a further five years. As one of the largest waste water treatment plants in Turkey, with a treatment capacity of two million population equivalents, it is designed for up to 500,000 m³ effluent/day in the final stage. By way of comparison: Istanbul has a total of approx. 15 million inhabitants, and more than 72 million people live in the whole of Turkey. This means that almost three percent of all effluent in Turkey will, in future, be treated in Ataköy.
The Ataköy waste water treatment plant employs state-of-the-art technology, and features a performance, which is even better than the strict EU limits. The treated effluent may be used for irrigation purposes, and, as a result of its efficient design and the fact that most of the energy from the biogas generated is utilised by means of a gas turbine, the plant also minimises energy consumption.
Plant photos: www.wte.de
Producing biogas from sewage sludge
The latest process engineering and high quality technology are used at the plant. Carbon, nitrogen and phosphorus are eliminated in the plant. The sewage sludge obtained is used for producing biogas in a total of six fermentation towers. Power for the waste water treatment plant can be supplied entirely via a combined heat and power installation, which is operated with the biogas which is obtained and also with natural gas. The heat generated by the combined heat and power installation is used for further drying of the sewage sludge. Exhaust air is treated by means of ozone in order to avoid malodorous emissions.
The crucial factors for placing the order with the construction syndicate were the modern WTE technology as well as the low energy consumption of the equipment used. The GEA Westfalia Separator Group was able to meet this requirement with the decanters included in the quote, which featured the lowest energy consumption figures compared with the competition.
Low specific energy consumption due to the decanters used
The effluent is roughly pre-clarified by sedimentation and mechanical rakes, and the resultant primary sludge is treated in the Ataköy waste water treatment plant in two UCF 466 thickening decanters.
The surplus activated sludge from the biological clarification stage, which follows the mechanical clarification stage, is thickened by eight UCD 536 decanters. This machine type guarantees a very low specific energy consumption of less than 1.2 kWh/m3. Even in conjunction with significantly fluctuating feed concentrations, the integrated Westfalia Separator® varipond® regulates the level of liquid in the decanter bowl so precisely that the concentration of the thickened solids can be set to a constant value which can be maintained accurately. It thus guarantees a discharge with a constant dry matter of six percent to be used in the downstream digestion tower. After remaining in the digestion tower for approx. 25 – 28 days, the digested sludge is discharged and dewatered by means of a further six UCD 536 dewatering decanters.
Decanter UCF 466
Local maintenance, repairs and service
To reflect the importance of the investment, it is planned that the major project will be officially opened in the presence of the Turkish Prime Minister. In the course of the next few years, Turkey will invest several billion Euros in effluent disposal. At present, only approx. 40 percent of the effluent volume in Turkey are connected to a total of around 200 waste water treatment plants. More than 180 decanters from the GEA Westfalia Separator Group operate in these waste water treatment plants for dewatering and thickening sludge, and the UCD 536 type alone accounts for more than 50 of these decanters. The GEA Westfalia Separator Group subsidiary in Turkey, which is based in Izmir and Istanbul, handles complete maintenance, repairs and service for all these centrifuges.
Westfalia Separator Sanayi ve Ticaret Ltd. Sti.
Westfalia Separator Sanayi ve Ticaret Ltd. Sti. is an independent subsidiary of the GEA Westfalia Separator Group, and recently celebrated its ten-year anniversary. After its foundation, the company quickly established itself as a leader in this branch; one reason for this success has been the company’s excellent processing and support for the effluent market in Turkey. Westfalia Separator Turkey also has the only “authorized workshop” for GEA Westfalia Separator Group centrifuges in the country, and is thus in an excellent position to provide service, maintenance and repair work for the many decanters at the Turkish waste water treatment plants.