Abstract Investigation of a Commercial Product (BiOWiSH­­TM) for Nitrogen Management Eva Lee BiOWiSH–Aqua, which has the capability of treating nitrogen from wastewater through bioaugmentation, is a commercial product consisting of a blend of microorganisms developed by BiOWiSH Technologies. A study of the treatment of nitrogen compounds (i.e. , , and ) using Biowish–Aqua was conducted using small scale experiments (flask experiments) and large scale experiments (column reactor experiments). In this work, column reactors were created to test Biowish–Aqua’s nitrogen treating capabilities by providing enough depth to simulate the dissolved oxygen gradient that can be observed in a pond. The results show that the optimal growth conditions for both ammonia assimilating and denitrifying bacteria are an anoxic environment with a carbon-to-nitrogen ratio of 2:1. Under this optimal growth environment, Biowish–Aqua was able to assimilate ammonia with a zero order k value of 3.06 ppm/day. Also, under the same conditions, Biowish–Aqua was able to eliminate nitrate ( ) and nitrite ( ) at a rate of 9.58 ppm/day and 5.64 ppm/day respectively. The experiments also suggested that with a C:N ratio of 2:1, Biowish–Aqua did not have an effect in slowing the hydrolysis of urea. Overall, this research suggests that the application of Biowish–Aqua is a feasible nitrogen removing strategy for wastewater with initial presence of ammonia and nitrate between 10 to 20 ppm. Keywords: Ammonia assimilation, Bioaugmentation, BiOWiSH, Denitrification