Resistance of aerobic granular sludge microbiomes to periodic loss of biomass
Raquel Liébana,
Oskar Modin,
Frank Persson,
Malte Hermansson,
Britt-Marie Wilén
Affiliations
Raquel Liébana
Division of Water Environment Technology, Department of Architecture and Civil Engineering, Chalmers University of Technology, Sven Hultins gata 6, SE 412 96, Gothenburg, Sweden; AZTI, Marine Research Division, Basque Research Technology Alliance (BRTA), Txatxarramendi Ugartea z/g, 48395, Sukarrieta, Bizkaia, Spain; Corresponding author. AZTI, Marine Research Division, Basque Research Technology Alliance (BRTA), Txatxarramendi Ugartea z/g, 48395, Sukarrieta, Bizkaia, Spain
Oskar Modin
Division of Water Environment Technology, Department of Architecture and Civil Engineering, Chalmers University of Technology, Sven Hultins gata 6, SE 412 96, Gothenburg, Sweden
Frank Persson
Division of Water Environment Technology, Department of Architecture and Civil Engineering, Chalmers University of Technology, Sven Hultins gata 6, SE 412 96, Gothenburg, Sweden
Malte Hermansson
Department of Chemistry and Molecular Biology, University of Gothenburg, Medicinaregatan 9E, SE-413 90, Gothenburg, Sweden
Britt-Marie Wilén
Division of Water Environment Technology, Department of Architecture and Civil Engineering, Chalmers University of Technology, Sven Hultins gata 6, SE 412 96, Gothenburg, Sweden
Granular sludge is a biofilm process used for wastewater treatment which is currently being implemented worldwide. It is important to understand how disturbances affect the microbial community and performance of reactors. Here, two acetate-fed replicate reactors were inoculated with acclimatized sludge and the reactor performance, and the granular sludge microbial community succession were studied for 149 days. During this time, the microbial community was challenged by periodically removing half of the reactor biomass, subsequently increasing the food-to-microorganism (F/M) ratio. Diversity analysis together with null models show that overall, the microbial communities were resistant to the disturbances, observing some minor effects on polyphosphate-accumulating and denitrifying microbial communities and their associated reactor functions. Community turnover was driven by drift and random granule loss, and stochasticity was the governing ecological process for community assembly. These results evidence the aerobic granular sludge process as a robust system for wastewater treatment.
