TY - JOUR
T1 - Simultaneous nitrification and denitrification in microbial community-based polyhydroxyalkanoate production
AU - Estévez-Alonso, Ángel
AU - van Loosdrecht, Mark C.M.
AU - Kleerebezem, Robbert
AU - Werker, Alan
PY - 2021
Y1 - 2021
N2 - 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.
AB - 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.
KW - Dissolved oxygen
KW - Nitrification
KW - Polyhydroxyalkanoates (PHA)
KW - Simultaneous nitrification and denitrification (SND)
KW - Waste activated sludge
UR - http://www.scopus.com/inward/record.url?scp=85108601879&partnerID=8YFLogxK
U2 - 10.1016/j.biortech.2021.125420
DO - 10.1016/j.biortech.2021.125420
M3 - Article
AN - SCOPUS:85108601879
SN - 0960-8524
VL - 337
JO - Bioresource Technology
JF - Bioresource Technology
M1 - 125420
ER -