In recent years, a whole array of new water treatment technologies have been developed. Anaerobic digestion allows the production of a high value energy source (methane) via waste water treatment. A subsequent anaerobic conversion of ammonium to N2 is expected to the possible in the future. Further, bio-membrane reactors are under development and advanced monitoring tools, such as molecular biology and stable isotope tracer techniques can be applied. During a bilateral project with China these knowledge concerning these technologies can be transferred.