| Description |
To study the PAO and DPAO ecophysiology, a bench top EPBR batch reactor fed with primary effluent from Central Valley Water Reclamation Facility, supplied with additional carbon from a synthetic fermenter, operated for 168 days. Although the removal efficiencies varied throughout entire reactor operation the average P, TIN and sCOD removal percentages were 56±24%, 78±24%, and 87±11%, respectively. Microbial diversity of PAOs and DPAOs showed that Candidatus Accumulibacter Phosphatis clade IA, IIC, and IID were the most abundant, with IID maintaining the highest and most consistent gene copy number throughout operation. DPAO within the reactor were only able to use nitrate as electron acceptors for denitrification. The DPAOs showed a P accumulation activity rate of (k = -0.002 𝑚𝑖𝑛$%) and denitrification rate of (k = -0.009 𝑚𝑖𝑛$%). Amplicon sequencing targeting the V4 hypervariable region of 16S rRNA gene revealed that Rhodocyclaceae relative abundance was the most prominent family from day 20 to 95 with 2.8%, 28.7%, respectively. Within the Rhodocyclaceae family classification the most abundant PAOs were Dechloromonas with 28.5%, 1.7%, and Accumulibacter with 1.74%, 11.2% on day 20, and 95, respectively. A class taxonomic level shift from Beta to Alpha protobacteria deteriorated reactor operations. Alpha protobacteria such as Defluviicoccus, a Know competitors of PAOs, showed a 29.4% increase in relative abundance from day 95 to 169 inhibiting reactor operations. Ongoing research is being conducted based on this lab-scale reactor to further study DPAOs ecology and BNR removal kinetics. A 41.6 L 𝐴'𝑂𝐴 anoxic/anaerobic/aerobic/anoxic continuous flow though reactor currently operates at CVWRF. The purpose of this reactor is to compare and contrast the effectiveness of BNR with primary settled sludge and side stream RAS fermentation. To cultivate, identify and quantify DPAO activity. Preliminary results show P, TIN and sCOD removal percentages of 65±28%, 43±23%, and 72±29%, respectively. Effluent concentrations currently meet Utah's newly established total maximum daily limits for phosphorus and total inorganic nitrogen. |
