23 1 From proof of feasibility to marketable product After proof of feasibility and the development of a suitable reactor design, the next priority for successful introduction of the ePhos® process to the market was making sure there was sufficient availability of magnesium consumed by the sacrificial electrodes in electrochemically forming the struvite. We were able to confirm the technical and logistical availability of cast magnesium bar supplies in negotiations with the world's lar- gest supplier of raw magnesium. Due to the rectangular shape of the magnesium bars, however, the design of the original tubular reactor vessel was changed to rectangular geometry. In addition, a great deal of information and numerous requi- rements mentioned in discussions with potential customers were very helpful during development. Particularly important insights were able to be obtained and incorporated during an initial pilot phase using a wastewater treatment plant in northern Germany that relied on biological elimination of phosphorus (see p. 112). We presented the process jointly with our licensee at their trade show booth in Chicago during the Water Environment Federation’s Annual Technical Exhibition and Conference WEFTEC in October 2015. Again, we were able to pick up im- portant suggestions and requests from interested visitors and potential customers, for example about automation, and take these into account during the development work. The OVIVO company, as our licensee, will build and sell the installations in orth merica according to our specifications, while raunho- fer IGB will further develop the technology and be available to the company and its customers for specific application tasks The struvite recovered with the ePhos® process is free of biological material and can be immediately employed as high- quality agricultural fertilizer. The experience at the booth in Chicago was surprising in that many of the plant operators from the United States who wished to employ the ePhos® process also wanted to locally market the struvite themselves rather than turning it over to an external purchaser for supra- regional sales. The motivation for investing in the new phosphorus recovery technology resulted from the new, extremely low discharge limits for phosphorus in the USA. For this reason, the bio- nutrient removal process using anaerobic sludge digestion is increasingly popular there. However, spontaneous precipitation of struvite represents an operational problem associated with considerable costs for them. Current interest has also increased in Germany as a result of the amendment to the German was- tewater treatment regulations and the constantly rising prices for fertilizer. As a result, we are talking to industrial partners in order to commence market introduction in Europe during the leading industry trade show IFAT coming up in May 2016.