Ecological Insight into the Deterioration of Autotrophic Nitrogen Removal in One-Stage Partial Nitritation and Anammox System During Environmental Disturbance

Abstract

The ecological understanding of a one-stage partial nitritation and anammox (PN/A) system, especially when facing environmental disturbances, is beneficial for engineering optimization, but there remain deficiencies. In this study, we focus on the connection between the ecological characteristics and the performance of a one-stage PN/A during the disturbance. The disturbance caused an inevitable community succession of the microbial with decreased community diversity and complexity. During long-term stable operation, the community diversity and complexity recovered except the autotrophic nitrogen removal. A delayed response of the functional bacteria abundance was observed compared to the decreased autotrophic nitrogen removal performance of the one-stage PN/A. As the experimental results revealed, the ecological fluctuation of the community with decreasing resistance and resilience was the driving force that fatally collapsed the one-stage PN/A. The successional pattern of the one-stage PN/A community was conducive to the diagnosis, prediction, and optimization of the one-stage PN/A system.

Keywords: Microbial community, diversity, successional pattern, partial nitritation and anammox, disturbance