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Behavior of activated sludge systems with an active heterotrophic biomass inflow – a novel perspective for sludge minimization
Author(s) -
Allı Buşra,
İnsel Güçlü,
Artan Nazik,
Orhon Derin,
Sözen Seval
Publication year - 2018
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.5368
Subject(s) - biomass (ecology) , activated sludge , heterotroph , inflow , particulates , chemistry , environmental science , pulp and paper industry , environmental engineering , sewage treatment , ecology , bacteria , biology , genetics , physics , organic chemistry , mechanics , engineering
BACKGROUND This study evaluated the microbial behavior of activated sludge systems operated with an active heterotrophic biomass inflow. The evaluation focused on the possibility of sludge minimization. Thus, related process stoichiometry was derived on the basis of mass balance for essential parameters. RESULTS Stoichiometric relationships showed that the reactor holds a larger amount of biomass without the controlling impact of the sludge age, which decreases the magnitude of microbial growth compared with endogenous decay. Consequently, the observed yield, Y OBS becomes much lower than what may be observed in conventional activated sludge systems. This stoichiometry exactly defines the microbial basis of the OSA ( oxic/settling/anaerobic) system and identifies the interchange stream connecting the anaerobic reactor to the aerobic main reactor as the source of the active biomass inflow. Therefore, biomass inflow, largely overlooked in related studies, offers a novel microbial perspective for the merit of the OSA process in minimizing sludge generation. CONCLUSION The impact of lower Y OBS , while explaining lower active biomass production, cannot be extrapolated to cover inert particulate COD fractions, namely a similar reduction in the initial inert COD and the residual particulate microbial products. Future studies should be directed to explore the fate of residual particulate compounds. © 2017 Society of Chemical Industry