"For both economic and environmental reasons, maximal use of resources present in wastewater is becoming a very important issue. From this perspective, wastewater is not seen as waste that must be disposed off, but as resource that should be utilized. For energy recovery, anaerobic wastewater treatment is an ideal option, but further research and further developments on the application of combined systems for organics and nitrogen removal under low to moderate temperature conditions are deemed necessary to overcome challenges on extensive applications. The temperature aspect is most important, because even in moderate regions such as Central Europe, the average temperature of wastewater is not higher than 15 °C and e.g. in Scandinavia can be even much lower. Under such conditions, heating of the entire wastewater stream to temperatures favorable for anaerobic digestions and/or e.g. Anaerobic Ammonia Oxidation (ANAMMOX) process (around 30°C) is economically impossible.Within the proposed project, the researcher will investigate the feasibility of combined anaerobic-aerobic treatment of municipal wastewater, specifically 1) at the temperature of municipal wastewater (<15 °C) and 2) using biofilm bioreactors for nitrogen removal to obtain robust and stabile biotechnology. The research fellow will apply number of novel and advanced techniques (MRI, NMR, FISH, microelectrodes) to elucidate mass transport phenomena in biofilms carrying out nitrogen removal from wastewater. As shown in literature, transport of nitrogen species and oxygen in the biofilm is the key phenomenon for control of the nitritation/denitritation process.The output of this project is expected to improve ecological and economical aspects of municipal wastewater treatment in Europe, leading to less energy dependent wastewater treatment plants, less excess sludge production and lower operational costs."