Nitrogen cycling and controlling factors in constructed urban stormwater wetlands

This thesis determined the rates of different dissimilatory NOx reduction processes and their controlling factors in four constructed urban stormwater wetlands across Melbourne, Australia. DNRA was the dominant NOx reduction process under the environmentally relevant conditions whereas DNF dominated under ideal conditions in slurries. NOx reduction was enhanced more by NOC than acetate. Fe2+ showed that Fe2+ had a significant effect on the partitioning between DNF and DNRA. Both DNF and DNRA decreased, but DNF decreased to a greater extent after sediments were dried. In contrast, rates of both DNF and DNRA increased with increasing temperature in slurries.