Sulfur Coupled Dissimilatory Nitrate Reduction to Ammonium in Anaerobic Freshwater Sediments

Abstract

The study sought to document dissimilatory nitrate reduction to ammonium (DNRA) in multiple freshwater ecosystems in an effort to expand the models of nitrogen transformation in anaerobic pore water. The data was gathered using pore water equilibration probes to test the hydrogen sulfide and ammonium ionic concentrations of benthic pore waters from three ecosystems; freshwater ponds, streams and wetlands near Hickory Comers, MI in the summer of 2005. Results show no significant relationship between spectrophotometric ally measured amounts of H2S and NH4 (0.03 to> 100.0µL) in at each ecosystem studied. The results are inconclusive about the prevalence of DNRA and the fate of nitrate in freshwater systems, but suggest a relationship between H2S and Nh4 in the benthic freshwater environment.