The effect of hydraulic retention time on the stability of aerobically grown microbial granules.
Reads0
Chats0
TLDR
The aim of this study is to evaluate the effect of hydraulic retention time (HRT) on the development of aerobically grown microbial granules.Abstract:
Aims: The aim of this study is to evaluate the effect of hydraulic retention time (HRT) on the development of aerobically grown microbial granules.
Methods and Results: Five column-shaped sequential aerobic sludge blanket reactors (SASBRs) were seeded with aerobically grown microbial granules and operated in a cyclic mode at different HRTs. At the shortest HRT of 1 h, the strong hydraulic pressure triggered biomass washout and led to reactor failure. At the longest HRT of 24 h, which represented the weakest hydraulic selection in this study, aerobic granules were gradually substituted by bioflocs because of the lower frequency of volumetric exchange. Within the optimum range of HRTs from 2 to 12 h, however, aerobic granules became stabilized in the presence of adequate hydraulic selection in the reactors, with good mixed liquor volatile suspended solids (MLVSS) retention, high volumetric chemical oxygen demand (COD) removal, low sludge volume index (SVI) values, good effluent quality, low sludge production rate, stronger and more compact structures, high cell hydrophobicity and high ratios of extracellular polysaccharides (PS) to extracellular proteins (PN).
Conclusions: HRTs between 2 and 12 h provided the hydraulic selection pressures favourable for the formation and maintenance of stable aerobic granules with good settleability and activity.
Significance and Impact of the Study: This is the first systematic study on the effect of HRT on heterotrophic aerobic granules. The results of the investigation are useful in understanding how aerobic granules can be applied for wastewater treatment.read more
Citations
More filters
Journal ArticleDOI
Simultaneous nitrification, denitrification, and phosphorus removal from nutrient‐rich industrial wastewater using granular sludge
TL;DR: In this article, a lab-scale sequencing batch reactor, seeded with granular sludge developed using synthetic wastewater, was operated for 13 months under alternating anaerobic and aerobic conditions.
Journal ArticleDOI
Formation and instability of aerobic granules under high organic loading conditions.
TL;DR: The cultivation and instability of aerobic granular sludge in a sequencing batch reactor under high loading conditions were investigated and compact bacteria-dominated aerobic granules were not stable and transited to large-sized filamentous ones gradually, increasing the hydrophobicity and specific gravity of the sludge.
Journal ArticleDOI
Nitrogen and phosphorus removal from an abattoir wastewater in a SBR with aerobic granular sludge
Daniel P. Cassidy,E. Belia +1 more
TL;DR: The results indicate that conventional S BRs treating wastewaters with flocculating sludge can be converted to granular SBRs by reducing the settle time.
Journal ArticleDOI
Selection pressure-driven aerobic granulation in a sequencing batch reactor
TL;DR: It appears that the formation and characteristics of aerobic granules can be manipulated through properly adjusting either the settling time or the exchange ratio in SBR, suggesting that aerobic granulation is a selection pressure-driven cell-to-cell immobilization process.
Journal ArticleDOI
An integrative review of granular sludge for the biological removal of nutrients and recalcitrant organic matter from wastewater
Mari K.H. Winkler,Christophe F. Meunier,Olivier Henriet,Jacques Mahillon,María Eugenia Suárez-Ojeda,Guido Del Moro,Marco De Sanctis,Claudio Di Iaconi,David G. Weissbrodt +8 more
TL;DR: The macro-scale factors impacting granulation, the physical-chemical characteristics of granular sludge, and fundamental and applied questions driven by the microbial ecology of granularity sludge are critically examined to generate useful concepts for process design and evaluation in engineering practice.
References
More filters
Book
Wastewater Engineering Treatment Disposal Reuse
TL;DR: Wastewater Engineering: An Overview of Wastewater Engineering, Methods and Implementation Considerations as mentioned in this paper is a good starting point for a discussion of the issues of wastewater engineering. But, it is not a complete survey of the entire literature.
Journal ArticleDOI
Adherence of bacteria to hydrocarbons: A simple method for measuring cell‐surface hydrophobicity
Journal ArticleDOI
Bioflocculation in activated sludge: an analytic approach
TL;DR: In this paper, a study on the physico-chemical structure of activated sludge flocs was carried out to get a better insight in its relationship with sludge settleability.
Journal ArticleDOI
High organic loading influences the physical characteristics of aerobic sludge granules.
TL;DR: Aims: The effect of high organic loading rate (OLR) on the physical characteristics of aerobic granules was studied.