Effects of salinity changes on freshwater and low-salinity nitrifying biofilter media. Nitrifying biofilter media

Nitrification rate was used to assess biofilter recovery from varying salinities. Freshwater filters showed full recovery after a transition to 3 ppt, but none in 20 or 33 ppt. Brackish filters (3 ppt) showed slight recovery after transitioning to 20 ppt, but none with a transition to 33 ppt. 16s rRNA sequencing revealed an overall higher proportion of nitrifiers in the brackish filters.