Effect of water velocity on ammonium and nitrite removal in pilot scale fixed bed biofilters

Estimation of nitrifying and heterotrophic bacterial activity in biofilm formed on RAS biofilter carriers by respirometry

“…The crux is to find methods to assess the biofilter performance. Currently, RAS biofilter performance is typically evaluated based on turnover rates of ammonium or nitrite to nitrate using batch reactors with controlled substrate spiking (Kamstra et al, 2017;Kinyage and Pedersen, 2016;Mnyoro et al, 2021;Navada et al, 2021). The reduction of a single substrate (total ammonium/ammonia-nitrogen (TAN) or nitrite) over time and the increase of the end-product (nitrate) gives information about biofilter performance, but it does not reflect the actual activity of nitrifiers in biofilters (Surmacz-Gorska et al, 1996).…”