Exploring the Limits of Polyhydroxyalkanoate Production by Municipal Activated Sludge

Ruizhe Pei*, Ángel Estévez-Alonso, Laura Ortiz-Seco, Mark C.M. Van Loosdrecht, Robbert Kleerebezem, Alan Werker

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

7 Citations (Scopus)
36 Downloads (Pure)


Municipal activated sludge can be used for polyhydroxyalkanoate (PHA) production, when supplied with volatile fatty acids. In this work, standardized PHA accumulation assays were performed with different activated sludge to determine (1) the maximum biomass PHA content, (2) the degree of enrichment (or volume-to-volume ratio of PHA-accumulating bacteria with respect to the total biomass), and (3) the average PHA content in the PHA-storing biomass fraction. The maximum attained biomass PHA content with different activated sludge ranged from 0.18 to 0.42 gPHA/gVSS, and the degree of enrichment ranged from 0.16 to 0.51 volume/volume. The average PHA content within the PHA-accumulating biomass fraction was relatively constant and independent of activated sludge source, with an average value of 0.58 ± 0.07 gPHA/gVSS. The degree of enrichment for PHA-accumulating bacteria was identified as the key factor to maximize PHA content when municipal activated sludge is directly used for PHA accumulation. Future optimization should focus on obtaining a higher degree of enrichment of PHA-accumulating biomass, either through selection during wastewater treatment or by selective growth during PHA accumulation. A PHA content in the order of 0.6 g PHA/g VSS is a realistic target to be achieved when using municipal activated sludge for PHA production.

Original languageEnglish
Pages (from-to)11729-11738
JournalEnvironmental Science and Technology
Issue number16
Publication statusPublished - 2022


  • activated sludge
  • biopolymers
  • municipal wastewater treatment
  • polyhydroxyalkanoate (PHA)
  • resource recovery


Dive into the research topics of 'Exploring the Limits of Polyhydroxyalkanoate Production by Municipal Activated Sludge'. Together they form a unique fingerprint.

Cite this