TY - JOUR
T1 - Cooperation between Candidatus Competibacter and Candidatus Accumulibacter clade I, in denitrification and phosphate removal processes
AU - Rubio-Rincón, F. J.
AU - Lopez-Vazquez, C. M.
AU - Welles, L.
AU - van Loosdrecht, M. C.M.
AU - Brdjanovic, D.
PY - 2017
Y1 - 2017
N2 - Although simultaneous P-removal and nitrate reduction has been observed in laboratory studies as well as full-scale plants, there are contradictory reports on the ability of PAO I to efficiently use nitrate as electron acceptor. Such discrepancy could be due to other microbial groups performing partial denitrification from nitrate to nitrite. The denitrification capacities of two different cultures, a highly enriched PAO I and a PAO I-GAO cultures were assessed through batch activity tests conducted before and after acclimatization to nitrate. Negligible anoxic phosphate uptake coupled with a reduction of nitrate was observed in the highly enriched PAO I culture. On the opposite, the PAO I-GAO culture showed a higher anoxic phosphate uptake activity. Both cultures exhibited good anoxic phosphate uptake activity with nitrite (8.7 ± 0.3 and 9.6 ± 1.8 mgPO4-P/gVSS.h in the PAO I and PAO I-GAO cultures, respectively). These findings suggest that other microbial populations, such as GAOs, were responsible to reduce nitrate to nitrite in this EBPR system, and that PAO I used the nitrite generated for anoxic phosphate uptake. Moreover, the simultaneous denitrification and phosphate removal process using nitrite as electron acceptor may be a more sustainable process as can: i) reduce the carbon consumption, ii) reduce oxygen demand of WWTP, and iii) due to a lower growth yield contribute to a lower sludge production.
AB - Although simultaneous P-removal and nitrate reduction has been observed in laboratory studies as well as full-scale plants, there are contradictory reports on the ability of PAO I to efficiently use nitrate as electron acceptor. Such discrepancy could be due to other microbial groups performing partial denitrification from nitrate to nitrite. The denitrification capacities of two different cultures, a highly enriched PAO I and a PAO I-GAO cultures were assessed through batch activity tests conducted before and after acclimatization to nitrate. Negligible anoxic phosphate uptake coupled with a reduction of nitrate was observed in the highly enriched PAO I culture. On the opposite, the PAO I-GAO culture showed a higher anoxic phosphate uptake activity. Both cultures exhibited good anoxic phosphate uptake activity with nitrite (8.7 ± 0.3 and 9.6 ± 1.8 mgPO4-P/gVSS.h in the PAO I and PAO I-GAO cultures, respectively). These findings suggest that other microbial populations, such as GAOs, were responsible to reduce nitrate to nitrite in this EBPR system, and that PAO I used the nitrite generated for anoxic phosphate uptake. Moreover, the simultaneous denitrification and phosphate removal process using nitrite as electron acceptor may be a more sustainable process as can: i) reduce the carbon consumption, ii) reduce oxygen demand of WWTP, and iii) due to a lower growth yield contribute to a lower sludge production.
KW - DGAO
KW - DPAO
KW - EBPR
KW - GAO
KW - PAO I
UR - http://resolver.tudelft.nl/uuid:bf0113e9-571f-409e-acdc-d20e2e4c8486
UR - http://www.scopus.com/inward/record.url?scp=85018327295&partnerID=8YFLogxK
U2 - 10.1016/j.watres.2017.05.001
DO - 10.1016/j.watres.2017.05.001
M3 - Article
C2 - 28486166
AN - SCOPUS:85018327295
SN - 0043-1354
VL - 120
SP - 156
EP - 164
JO - Water Research
JF - Water Research
ER -