Case Study: Glencoe, Ontario Wastewater Treatment Plant Post Lagoon Nitrification And Effluent Polishing System Features SAGR Process

By Merle Kroeker, P. Eng, Project Development Engineer, Nelson Environmental Inc.,
and Ken Musyoka, BSc. ChemEng, Chemical Engineering, Nelson Environmental Inc.

Small communities in the United States and Canada are challenged with the need to upgrade aging wastewater treatment facilities to meet increasingly stringent effluent quality limits. Included in these limits is an intensified focus on nutrient removal including ammonia reduction. With limited budgets always a factor and technology playing catch up with the demand, until recently, the upgrade options were extremely limited. This is particularly true in cold climate areas where no proven cost effective tertiary treatment technologies following oxidation ponds or aerated lagoons were available to meet the required low ammonia levels.

Many treatment lagoons are able to partially nitrify during the warmer summer months when water temperatures rise above 15° C. This is due to enhanced biochemical reaction rates at higher temperatures, which leads to some nitrification within the lagoon. Nitrifying activity significantly slows down in winter as lagoon water temperature decreases and drops below 4° C. Reaction rates and subsequent ammonia removals are near zero at these low temperatures.