Survey of full‐scale sidestream enhanced biological phosphorus removal (S2EBPR) systems and comparison with conventional EBPRs in North America: Process stability, kinetics, and microbial populations

Abstract

Sidestream EBPR (S2EBPR) is an emerging alternative process to address common challenges in EBPR related to weak wastewater influent and may improve EBPR process stability. A systematic evaluation and comparison of the process performance and microbial community structure was conducted between conventional and S2EBPR facilities in North America. The statistical analysis suggested higher performance stability in S2EBPR than conventional EBPR, although possible bias associated with other plant‐specific factors might have affected the comparison. Variations in stoichiometric values related to EBPR activity and discrepancies between the observed values and current model predictions suggested a varying degree of metabolic versatility of PAOs in S2EBPR systems that warrant further investigation. Microbial community analysis using various techniques suggested comparable known candidate PAO relative abundances in S2EBPR and conventional EBPR systems, whereas the relative abundance of known candidate GAOs seemed to be consistently lower in S2EBPR facilities than conventional EBPR facilities. 16S rRNA gene sequencing analysis revealed differences in the community phylogenetic fingerprints between S2EBPR and conventional facilities and indicated statistically higher microbial diversity index values in S2EBPR facilities than those in conventional EBPRs. Practitioner Points Sidestream EBPR (S2EBPR) can be implemented with varying and flexible configurations, and they offer advantages over conventional configurations for addressing the common challenges in EBPR related to weak wastewater influent and may improve EBPR process stability. Survey of S2EBPR plants in North America suggested statistically more stable phosphorus removal performance in S2EBPR plants than conventional EBPRs, although possible bias might affect the comparison due to other plant‐specific factors. The EBPR kinetics and stoichiometry of the S2EBPR facilities seemed to vary and are associated with metabolic versatility of PAOs in S2EBPR systems that warrant further investigation. The abundance of known candidate PAOs in S2EBPR plants was similar to those in conventional EBPRs, and the abundance of known candidate GAOs was generally lower in S2EBPR than conventional EBPR facilities. Further finer‐resolution analysis of PAOs and GAOs, as well as identification of other unknown PAOs and GAOs, is needed. Microbial diversity is higher in S2EBPR facilities compared with conventional ones, implying that S2EBPR microbial communities could show better resilience to perturbations due to potential functional redundancy.

Combined Enhanced Biological Phosphorus Removal (EBPR) and Nitrite Accumulation for Treating High-strength Wastewater

“…Compared to stage 2, the known GAO populations shifted to Candidatus Competibacter over Defluviicoccus with a relative abundance of 15.3-24.9% at stage 3. Factors that govern the changes in known GAO community composition remain unclear including SRT (Onnis-Hayden et al, 2020), C/P ratios (Majed and Gu, 2020) and carbon compositions (Shen and Zhou, 2016) have been evidenced to be associated with GAOs shifts. The accumulation of Defluviicoccus in the system may be due to the propionate in the feeding medium, which prefers propionate instead of acetate in order to maximize their production of PHAs with the same glycogen consumption (Dai et al, 2007).…”

“…Enhanced biological phosphorus removal (EBPR) has been widely applied in treating domestic wastewater, however, the application of EBPR for high-strength waste streams has hardly been explored. EBPR has been deemed as unsuitable due to the presumptions that the high-strength wastewater characteristics may not be suitable for polyphosphate accumulating organisms (PAOs), as well as concerns regarding the performance stability that are susceptible to microbial community competitions and other factors such as pH, temperature, solids retention time, influent carbon to phosphorus ratio and system configurations (Neethling et al, 2006, Onnis-Hayden et al, 2020). A limited number of studies using lab-scale EBPR reactors to treat synthetic high-strength wastewater showed promising overall P removal efficiency (~70%), but no process optimization and comprehensive evaluations of kinetics and mechanisms of the EBPR were performed in these studies (Bickers et al, 2003).…”

Machine Leaning-based Determination of Sampling Depth for Complex Environmental Systems: Case Study with Single-Cell Raman Spectroscopy Data in EBPR Systems

“…After performance evaluation on two synthetic datasets with or without linear relationship, the proposed algorithm and method were applied to investigate sampling size requirements with single-cell Raman spectroscopic dataset retrieved from eight microbial communities representing eight different wastewater reuse and reclamation facilities (WRRFs) located in North America 27, 42 . Details on these EBPR facilities, sampling and SCRS data acquisition were described in the methods section and in supporting information.…”

“…Briefly, each sludge sample was independently performed a phosphorus release and uptake kinetics batch test as described by Gu et al (2008) 39 . Raman-based phenotypic survey was performed on the sludge extracted throughout the batch test following the preparing and acquisition protocol described by Majed et al (2008) and Onnis-Hayden et al (2019) [40][41][42] . All spectra were acquired with a 400-1800 cm -1 range which is often referred as the "fingerprint range" for various cellular or biomass substances 6,23,43 .…”

“…CC-BY-NC-ND 4.0 International license available under a (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made The copyright holder for this preprint this version posted December 21, 2020. ; https://doi.org/10.1101/2020.12.18.423496 doi: bioRxiv preprint reuse and reclamation facilities (WRRFs) located in North America 27,42 . Details on these EBPR facilities, sampling and SCRS data acquisition were described in the methods section and in supporting information.…”