TY - JOUR
T1 - Long-term stability of a non-adapted aerobic granular sludge process treating fish canning wastewater associated to EPS producers in the core microbiome
AU - Paulo, Ana M. S.
AU - Amorim, Catarina L.
AU - Costa, Joana
AU - Mesquita, Daniela P.
AU - Ferreira, Eugénio C.
AU - Castro, Paula M. L.
N1 - Funding Information:
This work was supported by National Funds from FCT - Fundação para a Ciência e a Tecnologia , through the project MULTIBIOREFINERY - SAICTPAC/0040/2015 ( POCI-01-0145-FEDER-016403 ). We would also like to thank the scientific collaboration of CBQF under the FCT project UID/Multi/50016/2019 and of CEB under the FCT project UID/BIO/04469/2019 and BioTecNorte operation ( NORTE-01-0145-FEDER-000004 ) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. We would like to thank “A Poveira S.A.” (Póvoa de Varzim, Portugal) for providing the fish canning wastewater.
Publisher Copyright:
© 2020 Elsevier B.V.
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2021/2/20
Y1 - 2021/2/20
N2 - The tolerance of aerobic granular sludge (AGS) to variable wastewater composition is perceived as one of its greatest advantages compared to other aerobic processes. However, research studies select optimal operational conditions for evaluating AGS performance, such as the use of pre-adapted biomass and the control of wastewater composition. In this study, non-adapted granular sludge was used to treat fish canning wastewater presenting highly variable organic, nutrient and salt levels over a period of ca. 8 months. Despite salt levels up to 14 g NaCl L−1, the organic loading rate (OLR) was found to be the main factor driving AGS performance. Throughout the first months of operation, the OLR was generally lower than 1.2 kg COD m−3 day−1, resulting in stable nitrification and low COD and phosphorous levels at the outlet. An increase in OLR up to 2.3 kg COD m−3 day−1 disturbed nitrification and COD and phosphate removal, but a decrease to average values between 1 and 1.6 kg COD m−3 day−1 led to resuming of those processes. Most of the bacteria present in the AGS core microbiome were associated to extracellular polymeric substances (EPS) production, such as Thauera and Paracoccus, which increased during the higher OLR period. Ammonium-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) species were detected in AGS biomass; while AOB were identified throughout the operation, NOB were no further identified after the period of increased OLR. Different polyphosphate-accumulating organisms (PAOs) were detected along the process: Candidatus Accumulibacter, Tetrasphaera and Gemmatimonas. A non-adapted granular sludge was able to treat the fish canning wastewater and to tolerate salinity fluctuations up to 14 g L−1. Overall, a high microbial diversity associated to EPS producers allowed to preserve bacterial groups responsible for nutrients removal, contributing to the adaptation and long-term stability of the AGS system.
AB - The tolerance of aerobic granular sludge (AGS) to variable wastewater composition is perceived as one of its greatest advantages compared to other aerobic processes. However, research studies select optimal operational conditions for evaluating AGS performance, such as the use of pre-adapted biomass and the control of wastewater composition. In this study, non-adapted granular sludge was used to treat fish canning wastewater presenting highly variable organic, nutrient and salt levels over a period of ca. 8 months. Despite salt levels up to 14 g NaCl L−1, the organic loading rate (OLR) was found to be the main factor driving AGS performance. Throughout the first months of operation, the OLR was generally lower than 1.2 kg COD m−3 day−1, resulting in stable nitrification and low COD and phosphorous levels at the outlet. An increase in OLR up to 2.3 kg COD m−3 day−1 disturbed nitrification and COD and phosphate removal, but a decrease to average values between 1 and 1.6 kg COD m−3 day−1 led to resuming of those processes. Most of the bacteria present in the AGS core microbiome were associated to extracellular polymeric substances (EPS) production, such as Thauera and Paracoccus, which increased during the higher OLR period. Ammonium-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) species were detected in AGS biomass; while AOB were identified throughout the operation, NOB were no further identified after the period of increased OLR. Different polyphosphate-accumulating organisms (PAOs) were detected along the process: Candidatus Accumulibacter, Tetrasphaera and Gemmatimonas. A non-adapted granular sludge was able to treat the fish canning wastewater and to tolerate salinity fluctuations up to 14 g L−1. Overall, a high microbial diversity associated to EPS producers allowed to preserve bacterial groups responsible for nutrients removal, contributing to the adaptation and long-term stability of the AGS system.
KW - AGS
KW - Bacterial community
KW - Food industry wastewater
KW - Organic load
KW - Salt
UR - http://www.scopus.com/inward/record.url?scp=85096832271&partnerID=8YFLogxK
U2 - 10.1016/j.scitotenv.2020.144007
DO - 10.1016/j.scitotenv.2020.144007
M3 - Article
C2 - 33250239
AN - SCOPUS:85096832271
SN - 0048-9697
VL - 756
JO - Science of the Total Environment
JF - Science of the Total Environment
M1 - 144007
ER -
