Simultaneous nitrification and denitrification in microbial community-based polyhydroxyalkanoate production

Simultaneous nitrification and denitrification in microbial community-based polyhydroxyalkanoate production

Estevez Alonso, A. (TU Delft BT/Environmental Biotechnology; Wetsus, Centre for Sustainable Water Technology)
van Loosdrecht, Mark C.M. (TU Delft BT/Environmental Biotechnology)
Kleerebezem, R. (TU Delft BT/Environmental Biotechnology)
Werker, A. (Wetsus, Centre for Sustainable Water Technology)

2021

Microbial community-based polyhydroxyalkanoate (PHA) production has been demonstrated repeatedly at pilot scale. Ammonium, normally present in waste streams, might be oxidized by nitrifying bacteria resulting in additional aeration energy demand. The use of low dissolved oxygen (DO) concentrations allowed to reduce nitrifying rates by up to 70% compared to non-oxygen limiting conditions. At lower DO concentrations nitrate was used as alternative electron acceptor for PHA production and therefore, a constant PHA production rate could only be maintained if nitrate was sufficiently available. An optimum DO concentration (0.9 mgO₂/L) was found for which nitrification was mitigated but also exploited to supply requisite heterotrophic nitrate requirements that maintained maximum PHA production rates. PHA accumulations with such DO control was estimated to reduce oxygen demand by about 18%. This work contributes to establish fundamental insight towards viable industrial practice with the control and exploitation of nitrifying bacteria in microbial community-based PHA production.

Dissolved oxygen
Nitrification
Polyhydroxyalkanoates (PHA)
Simultaneous nitrification and denitrification (SND)
Waste activated sludge

https://doi.org/10.4233/uuid:6b4fde3d-d961-4ad1-bf4a-01664bbff9f8

https://doi.org/10.1016/j.biortech.2021.125420

0960-8524

Bioresource Technology, 337

Institutional Repository

journal article

© 2021 A. Estevez Alonso, Mark C.M. van Loosdrecht, R. Kleerebezem, A. Werker