This presentation by ASH DEC Umwelt AG describes the need for recycling phosphorous and the economic sector of the enterprise. There is further information on the process and the pilot plant. Finally, ASH DEC gives general information on their fertiliser product and explains their idea of joint operating company (in German).
ASH DEC (2008): P – und Naehrstoffduenger aus Klaerschlammaschen. Vienna: ASH DEC Umwelt AG. [Accessed: 17.08.2010] PDF