Abstract
SummaryPartial nitritation‐anammox (PNA) permits energy effective nitrogen removal. Today PNA is used for treatment of concentrated and warm side streams at wastewater treatment plants, but not the more diluted and colder main stream. To implement PNA in the main stream, better knowledge about microbial communities at the typical environmental conditions is necessary. In order to investigate the response of PNA microbial communities to decreasing substrate availability, we have operated a moving bed biofilm reactor (MBBR) at decreasing reactor concentrations (311–27 mg‐N l−1 of ammonium) and low temperature (13°C) for 302 days and investigated the biofilm community using high throughput amplicon sequencing; quantitative PCR; and fluorescence in situ hybridization. The anammox bacteria (Ca. Brocadia) constituted a large fraction of the biomass with fewer aerobic ammonia oxidizing bacteria (AOB) and even less nitrite oxidizing bacteria (NOB; Nitrotoga, Nitrospira and Nitrobacter). Still, NOB had considerable impact on the process performance. The anammox bacteria, AOB and NOB all harboured more than one population, indicating some diversity, and the heterotrophic bacterial community was diverse (seven phyla). Despite the downshifts in substrate availability, changes in the relative abundance and composition of anammox bacteria, AOB and NOB were small and also the heterotrophic community showed little changes in composition. This indicates stability of PNA MBBR communities towards decreasing substrate availability and suggests that even heterotrophic bacteria are integral components of these communities.
Highlights
Autotrophic nitrogen removal from wastewater can be achieved by partial nitritation together with anaerobic ammonium oxidation
Partial nitritation-anammox (PNA) is established for treatment of warm and concentrated wastewater side streams (Lackner et al, 2014), where the conditions for growth of aerobic ammonia oxidizing bacteria (AOB) and anammox bacteria are beneficial and inhibition of unwanted aerobic nitrite oxidation by nitrite oxidizing bacteria (NOB) can be effective
The competition between AOB and anammox bacteria with NOB and denitrifying bacteria is challenging at these conditions, which necessitates detailed a 2016 The Authors
Summary
Autotrophic nitrogen removal from wastewater can be achieved by partial nitritation together with anaerobic ammonium oxidation (anammox). Partial nitritation-anammox (PNA) saves energy due to a reduced need for aeration by > 50% (Siegrist et al, 2008) and enables a higher utilization of organic carbon for production of valuable products, for example, biogas, compared to conventional nitrogen removal with nitrification-denitrification. Together, this makes energy positive wastewater treatment plants (WWTPs) possible (Kartal et al, 2010). The conditions for PNA are much more challenging (De Clippeleir et al, 2013; Hu et al, 2013; Laureni et al, 2016).
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
