TY - JOUR
T1 - Exploring the Limits of Polyhydroxyalkanoate Production by Municipal Activated Sludge
AU - Pei, Ruizhe
AU - Estévez-Alonso, Ángel
AU - Ortiz-Seco, Laura
AU - Van Loosdrecht, Mark C.M.
AU - Kleerebezem, Robbert
AU - Werker, Alan
PY - 2022
Y1 - 2022
N2 - 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.
AB - 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.
KW - activated sludge
KW - biopolymers
KW - municipal wastewater treatment
KW - polyhydroxyalkanoate (PHA)
KW - resource recovery
UR - http://www.scopus.com/inward/record.url?scp=85136136755&partnerID=8YFLogxK
U2 - 10.1021/acs.est.2c03043
DO - 10.1021/acs.est.2c03043
M3 - Article
C2 - 35900322
AN - SCOPUS:85136136755
SN - 0013-936X
VL - 56
SP - 11729
EP - 11738
JO - Environmental Science and Technology
JF - Environmental Science and Technology
IS - 16
ER -