1. Description and working principle
The SHARON (Single reactor for High activity Ammonia Removal Over Nitrite) process takes place in a completely mixed reactor without biomass retention. It has been developed to treat high strength ammonia side streams from sludge digestion. The conventional means of converting ammonia to nitrogen gas is by utilizing the nitrification/denitrification process. In the SHARON® process, ammonia is converted directly to nitrite (as opposed to nitrate in conventional methods), and then directly to nitrogen gas (Solley, D. 2000). The conversion from ammonium to nitrite is described by the following formula:
NH4+ + 1.5 O2 ⇒ NO2- + H2O + 2 H+
(STOWA 2006)