Design and Operation of a Full-scale Sidestream Bioaugmentation Plant

In an effort to reduce the risk of chronic ammonia toxicity in the Red River during periods of low flow, and to reduce nitrogen loads to Lake Winnipeg, a dedicated centrate treatment plant, that uses sequencing batch reactors (SBRs) to nitrify and denitrify the centrate sidestream, was built at the North End Water Pollution Control Centre (NEWPCC). One of the purposes of the sidestream plant was to encourage nitrification in the low-solids retention time (SRT) mainstream reactors by seeding, or bioaugmenting, with nitrifiers from the SBRs. This paper presents the design features of the centrate treatment facility that were specifically included in the design to encourage bioaugmentation, as well as reporting on the performance of the sidestream treatment plant and its effects on the mainstream treatment plant. As most bioaugmentation work in North America has been based on computer simulations and benchscale tests, the full-scale performance results are important to the industry in developing proven design criteria.