The main goals of this research involve removal of nitrate (NO3) from stream water in a bacterially mediated process called denitrification where NO3 is converted to biologically inactive nitrogen gas. Specifically, the work investigates this denitrification process in films of algae and bacteria referred to as biofilms. This research will investigate when biofilms in streams and rivers are of significance in removing nitrates, how the effectiveness varies with the algal and bacterial species composition and species diversity, and under what conditions the nitrate removal by biofilm is maximized.
Input of dissolved nitrogen into aquatic systems, via agricultural runoff and atmospheric deposition of products of fossil-fuel combustion, has increased dramatically over the last century. High nitrate (NO3) content in groundwater poses significant health risks, and elevated NO3 loads discharged into the ocean from rivers are implicated in the formation of ''dead zones'' in coastal areas. Thus, understanding the process of this nitrate regulation and removal by bacteria is highly important.
