TY - JOUR
T1 - Aggregation of purple bacteria in an upflow photobioreactor to facilitate solid/liquid separation: Impact of organic loading rate, hydraulic retention time and water composition
AU - Blansaer, Naïm
AU - Alloul, Abbas
AU - Verstraete, Willy
AU - Vlaeminck, Siegfried E.
AU - Smets, Barth F.
PY - 2022
Y1 - 2022
N2 - Purple non-sulfur bacteria (PNSB) form an interesting group of microbes for resource recovery from wastewater. Solid/liquid separation is key for biomass and value-added products recovery, yet insights into PNSB aggregation are thus far limited. This study explored the effects of organic loading rate (OLR), hydraulic retention time (HRT) and water composition on the aggregation of Rhodobacter capsulatus in an anaerobic upflow photobioreactor. Between 2.0-14.6 gCOD/(L.d), the optimal OLR for aggregation was 6.1 gCOD/(L.d), resulting in a sedimentation flux of 5.9 kgTSS/(m2.h). For HRT tested between 0.04-1.00 d, disaggregation occurred at the relatively long HRT (1 d), possibly due to accumulation of thus far unidentified heat-labile metabolites. Chemical oxygen demand (COD) to nitrogen (6-35 gCOD/gN) and the nitrogen source (ammonium vs. glutamate) also impacted aggregation, highlighting the importance of the specific wastewater type and its pre-treatment. These novel insights to improve purple biomass separation pave the way for cost-efficient PNSB applications.
AB - Purple non-sulfur bacteria (PNSB) form an interesting group of microbes for resource recovery from wastewater. Solid/liquid separation is key for biomass and value-added products recovery, yet insights into PNSB aggregation are thus far limited. This study explored the effects of organic loading rate (OLR), hydraulic retention time (HRT) and water composition on the aggregation of Rhodobacter capsulatus in an anaerobic upflow photobioreactor. Between 2.0-14.6 gCOD/(L.d), the optimal OLR for aggregation was 6.1 gCOD/(L.d), resulting in a sedimentation flux of 5.9 kgTSS/(m2.h). For HRT tested between 0.04-1.00 d, disaggregation occurred at the relatively long HRT (1 d), possibly due to accumulation of thus far unidentified heat-labile metabolites. Chemical oxygen demand (COD) to nitrogen (6-35 gCOD/gN) and the nitrogen source (ammonium vs. glutamate) also impacted aggregation, highlighting the importance of the specific wastewater type and its pre-treatment. These novel insights to improve purple biomass separation pave the way for cost-efficient PNSB applications.
KW - Nutrient recovery
KW - Purple phototrophic bacteria
KW - Granular sludge
KW - Flocculation
KW - Granulation
U2 - 10.1016/j.biortech.2022.126806
DO - 10.1016/j.biortech.2022.126806
M3 - Journal article
C2 - 35131464
SN - 0960-8524
VL - 348
JO - Bioresource Technology
JF - Bioresource Technology
M1 - 126806
ER -