Feasibility of nutrients removal and its pathways using integrated anaerobic-aerobic sequencing batch reactor

https://doi.org/10.1016/j.biteb.2021.100912Get rights and content

Highlights

High NH3-N removal was achieved with less aeration exertion

Keeping DO less than 0.5 mg/L in anoxic phase not possible: a conceptual corrigendum

No excess sludge disposal from anoxic/aerobic SBR along the investigation period

Abstract

This research is a continuous work for a previous study, which contemplates the performance of the proposed bioreactor called integrated anaerobic-aerobic sequencing batch reactor (IAASBR) regarding the nutrients removal. This investigation is accomplished by two schemes; firstly, choosing the best anoxic/oxic time ratio in the Anx/O SBR compartment, secondly, changing the anaerobic hydraulic retention time (HRTan) to enhance the nutrients removal and sludge maintaining in it. The overall removal efficiencies of SCOD and NH3-N were high (94 ± 4% and 91 ± 10% as average) comparing with the overall removal efficiencies of TN and PO43−, where they were 38% and 6%, respectively in the best operating condition (Anx/O = 3.5 h/1.5 h). Nitrate removal by means of endogenous respiration is the most likely pathway. Furthermore, a conceptual corrigendum; DO concentration in the anoxic phase cannot be maintained at the level below 0.5 mg/L in the SBR unless there is an addition of organic matters.

Abbreviations

A.Eff
aerobic effluent
An.Eff
anaerobic effluent
A.Inf
aerobic influent
An.Inf
anaerobic influent
AOB
ammonia-oxidizing bacteria
ASBR
anaerobic sequencing batch reactor
bsCOD
biodegradable soluble chemical oxygen demand
DAF
Dissolved air flotation
DO
dissolved oxygen
EBPR
enhancing biological phosphorus removal
IAASBR
integrated anaerobic-aerobic sequencing batch reactor
MLSS
mixed liquor suspended solids
MLVSS
mixed liquor volatile suspended solids
nbSCOD
nonbiodegradable soluble COD
NH3-N
ammoniacal nitrogen
NO2-N
nitrite as nitrogen
NO3-N
nitrate as nitrogen
NOB
nitrite-oxidizing bacteria
ORP
oxidation-reduction potential
PAOs
Polyphosphate accumulation organisms
PO43−
Total phosphate
PSW
poultry slaughterhouse wastewater
SCOD
soluble chemical oxygen demands
SHW
slaughterhouse wastewater
SND
simultaneous nitrification and denitrification
SNDPR
simultaneous biological nitrification-denitrification and phosphate removal
SVI
sludge volume index
T
temperature
TN
total nitrogen
Van/Va
anaerobic-aerobic SBR volumetric ratio
Vf/VT
Volumetric exchange ratio

Keywords

Integrated anaerobic-aerobic SBR
Limited excess sludge production
Nutrients removal pathways
Simultaneous biological nitrification-denitrification and phosphate removal (SNDPR)
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