Pairing Anaerobic Ammonia Oxidation with Newly Discovered Nitrite-Supplying Metabolisms for Enhanced Mainstream Nitrogen Removal

Thesis (Ph.D.)--University of Washington, 2020In wastewater treatment, sidestream nitrogen removal with anaerobic ammonia oxidation (anammox) has reduced cost, energy demand, and potentially greenhouse gas (GHG) emission as compared to conventional nitrification-denitrification However, under mainstream conditions, nitrite oxidizing bacteria (NOB) outcompete anammox bacteria for the nitrite produced by ammonia oxidizing bacteria (AOB). Therefore, nitrite production is the bottleneck in mainstream anammox nitrogen removal. The ultimate goal of this research was to evaluate the potential of three newly discovered nitrite-producing metabolisms for more reliable nitrite supply to anammox: nitrate-dependent denitrifying anaerobic methane oxidizing archaea (n-damo), ammonia oxidizing archaea (AOA), and complete ammonia oxidizing bacteria (comammox). Nitrate-dependent denitrifying anaerobic methane oxidizing archaea (n-damo) anaerobically reduce nitrate with methane gas to produce nitrite that could support anammox nitrogen removal. AOB and NOB would produce nitrate aerobically for an anaerobic anammox and a n-damo compartment in which n-damo would convert some nitrate back to nitrite for anammox if supplied methane from anaerobic sludge digestion or a mainstream anaerobic membrane bioreactor (AnMBR). A techno-economic analysis revealed that AnMBR/AOB/anammox systems reduced cost and GHG emissions the most, while the AnMBR/AOB/anammox/n-damo systems saw very similar reductions to the AnMBR/AOB/anammox system while simultaneously circumventing the risk of nitrate accumulation by NOB, potentially allowing easier aeration control. Two newly discovered organisms of interest that could also supply nitrite to anammox under mainstream conditions are ammonia oxidizing archaea (AOA) and complete ammonia oxidizing bacteria (comammox), that are capable of ammonia and nitrite oxidation. AOA are known to co-operate with anammox in oxygen minimum zones (OMZs) where oxygen and ammonia (here considered as total ammonia plus ammonium) concentrations are low (similar to the mainstream) and counter-diffuse in opposite directions near the OMZ boundary. Low ammonia affinity AOA supply nitrite to anammox while outcompeting canonical NOB and AOB. AOA-anammox nitrogen removal was tested in both co-diffusing granular sludge and OMZ-like hollow fiber membrane aerated biofilm reactors (MABR). The AOA species Nitrososphaera viennensis was found only in the OMZ-like MABR environment while Nitrospira and anammox were abundant in both environments. Some of the Nitrospira detected were determined to be of comammox type. Similar to AOA, comammox have a high ammonia affinity but a low affinity for nitrite (their intermediate product) which gives anammox a competitive edge to access it. When comammox and anammox were inoculated into granular sludge and MABR reactors, co-operation between the two species was observed both experimentally and in theoretical models. Comammox abundance and nitrogen removal was higher in the MABR due to the same-counter-diffusing phenomenon that made low-affinity AOA a successful anammox partner in OMZs. It is concluded that low-ammonia concentrations are essential to select for AOA- or comammox-anammox nitrogen removal. In these nitrogen removal systems, online ammonium (NH4+) sensing would be highly advantageous, and thus a set of online electrodes targeting ions of interest were tested for their resiliency in anammox reactors. Polyvinyl chloride (PVC)-based potassium and ammonium electrodes were degraded in these reactors while poly-crystalline chloride probes did not. Potassium electrodes appeared to decay at the same rate in systems including active and inactivated granules while ammonium probes fouled faster in a biologically active system. These results motivate the need to understand the chemical effects of anammox granular sludge on ammonium probes. In summary, novel processes for applying annamox in mainstream wastewater treatment were demonstrated and elucidated with modelling, bioreactor operations, and molecular analysis. The results showed that cooperation between these newly discovered nitrite producing species and anammox in wastewater treatment can lead to reduced energy requirements while meeting effluent limitations and mitigating our impact on the global nitrogen cycle

Say a prayer for the boys "out there" : the greatest patriotic ballad of the season

Gift of Dr. Mary Jane Esplen.Piano vocal [instrumentation]A mighty nation hears a ringing call to arm [first line]Won't you say a prayer for the boys out there [first line of chorus]G [key]Moderato [tempo]Popular song [form/genre]Family praying at table, silhouette of soldier on duty ; Gertrude Cogert (photograph) [illustration]Starmer [graphic artist]Publisher's advertisement on back cover [note

America, I love you, you\u27re like a sweetheart of mine, [first line of chorus]

Performers: Gertrude CogertPiano and Voice (with lyrics