In the LIFE+ project ITEST, Increased Total Efficiency in Sewage Treatment, a technical solution for efficient and improved nitrogen removal from municipal wastewater was demonstrated. This technical solution, which is based on operating the sewage treatment plant (STP) at a temperature of about 20°C even during periods with a cold inflow using waste heat, has been tested in pilot scale at Hammarby Sjöstadsverk i Stockholm. In this report, the results and evaluation of the demonstration period of the technology, performed at Hammarby Sjöstadsverk, Stockholm is presented. The results show that the nitrogen removal increased in a treatment line operated at 20°C in comparison to the removal efficiency in a parallel line with fluctuating temperature, thus achieving lower output concentrations. The need for aeration was reduced, but on the other hand increased use of electrical power was needed to overcome the pressure drop in the heat exchanger. Among other parameters, choice of heat exchanger influences the life cycle assessment of the process.
Nyckelord: Increased nitrogen removal, pre-heating, sewage treatment, treatment efficiency, waste heat
Författare: Uwe Fortkamp, Christian Junestedt, Christian Baresel, Klara Westling, Mats EkLadda ner publikation