Changes in Bacterial Communities During Treatment of Municipal Wastewater in Arctic Wastewater Stabilization Ponds

Wastewater stabilization ponds (WSPs) are commonly used to treat municipal wastewater in the Canadian Arctic. Bacterial community structure and functionality remain mostly uncharacterized for arctic WSPs, yet presumed important treatment outcomes during 3-month summer season with open water WSPs. The objective of this study was investigate performance related temporal spatial changes putative function bacterial communities WSPs Pond Inlet Clyde River, Nunavut over two consecutive seasons. Influent raw contained a high organic load large (~9 log 16S rRNA copies/mL) belonging mainly Proteobacteria . Although designed be facultative ponds, both remained anaerobic neutral pH values (7.5–7.8) throughout season. Water quality data showed that nutrients [measured as carbonaceous biological oxygen demand (CBOD 5 )], total suspended solids, ammonia nitrogen were progressively reduced progressed. pond population size species richness depended on temperature (2–18°C), 8.5 copies/mL largest alpha diversities (Shannon-Wiener index 4-4.5) observed mid-season (late July). While phylogenetic beta diversity from locations similar, underwent significant ( p < 0.05) dominance Comamonadaceae, Geobacteracea , Porphyromonadaceae Multivariate distance based redundancy analysis predicted gene functionalities microbiota agreed results microbial removal (e.g., CBOD ) peaked middle coinciding period highest temperatures. Information will useful further development models predict outcomes, which could assess feasibility extreme climates. Higher temperatures resulted optimal processes nutrient summer. it is challenging control environmental factors passive system there some design considerations optimize regimes, such depth pond.