Nitrate purification is developing into a global megamarket. In many places nitrate purification of wastewater is non-existent. The market knows many players and access is difficult because of the abundance of existent technology. The approach of nitrate purification is conventional but nowadays technology is also being developed to use carbon next to nitrate in the wastewater, to produce methane (energy). A better name for this market is C/N cycle. The Netherlands own several technologies, such as Sharon, Anammox, Canon and Babe, and has plenty of in-house experience with water treatment.