Influence of Operating Parameters on the Per- Formance of a Continuously Aerated Sharon Reactor

+ − + + + → + H 2 O H NO O 5 . 1 NH 2 2 2 4 (1) In the SHARON (Single reactor High activity Ammonia Removal Over Nitrite) process, partial nitrification is establishing by working at high temperature (about 35°C) and maintaining an appropriate sludge retention time (SRT). The SHARON reactor is operated as a continuously stirred tank reactor (CSTR, chemostat) without biomass retention, so the sludge retention time equals the hydraulic retention time. The SHARON process is very well suited to reduce the load of streams with high ammonia concentration, rather than to meet strict effluent standards. It is applied for treating sludge digestion reject water in order to relieve the main wastewater treatment plant (WWTP) to which this stream is subsequently recycled. A full-scale SHARON process is operational since January 1999 at the Rotterdam Sluisjesdijk sludge treatment plant. In its original configuration, the SHARON process is operated under alternating aerobic and anoxic conditions, the latter serving for pH control by denitrification. Full-scale experience with the SHARON process has recently been described by van Kempen et al. (2001).