Comparing the Resistance, Resilience, and Stability of Replicate Moving Bed Biofilm and Suspended Growth Combined Nitritation–Anammox Reactors

• DOI: 10.1021/acs.est.6b05878
• Publication Date: 2017-04-05T08:37:49Z
• Authors: G. F. Wells; Y. Shi; M. Laureni; A. Rosenthal; I. Szivák; D. G. Weissbrodt; A. Joss; H. Buergmann; D. R. Johnson; E. Morgenroth
• Keywords: Anammox; Total suspended solids

Combined partial nitritation-anammox (PN/A) systems are increasingly being employed for sustainable removal of nitrogen from wastewater, but process instabilities present ongoing challenges practitioners. The goal this study was to elucidate differences in stability between PN/A variations employing two distinct aggregate types: biofilm [in moving bed reactors (MBBRs)] and suspended growth biomass. Triplicate each variation were studied under baseline conditions response a series transient perturbations. MBBRs displayed elevated NH4+ rates relative those counterparts over six months unperturbed operation also exhibited significantly greater variability performance. Transient perturbations led strikingly divergent yet reproducible behavior versus systems. A temperature perturbation prompted sharp reduction with no accumulation NO2- rapid recovery MBBRs, compared similar high level reactors. Pulse additions nitrification inhibitor (allylthiourea) only moderate declines performance decreases MBBRs. Quantitative fluorescence situ hybridization demonstrated significant enrichment anammox reactors, conversely proportionally higher AOB abundance Overall, increased susceptibility that (stability parameter), including longer times (resilience). No difference the maximal impact (resistance) apparent. Taken together, our results suggest architecture (biofilm vs growth) processes exerts an unexpectedly strong influence on stability.