Utilizing Constructed Wetlands for the Treatment of Concentrated Ammonia Waste Streams: A Pilot Study

A one hundred day preliminary pilot study was conducted to examine the nitrogen removal potential of a simple, high-rate, fill-and-drain ANAMMOX wetland. The wetland was planted with five native riparian plant species, seeded with supernatant from a granular ANAMMOX reactor, and fed ammonia rich centrate at three progressive loading rates. The pilot showed that it was possible to achieve nitrite and ammonia removal indicative of ANAMMOX metabolism at 60 days. However, maintaining the appropriate level of partial nitritation activity for maximum removals through arbitrary control of the fill-and-drain cycle proved to be challenging as loadings were increased. The results of this preliminary piloting effort show that significant nitrogen removal can be achieved in an intensive fill-and-drain wetland system with minimal operation and maintenance cost.