Simultaneous COD, nitrogen, and phosphate removal by aerobic granular sludge

2005 ◽  
Vol 90 (6) ◽  
pp. 761-769 ◽  
Author(s):  
M.K. de Kreuk ◽  
J.J. Heijnen ◽  
M.C.M. van Loosdrecht
Author(s):  
Anouk F. Duque ◽  
Vânia S. Bessa ◽  
Udo van Dongen ◽  
Merle K. de Kreuk ◽  
Raquel B. R. Mesquita ◽  
...  

Abstract The presence of toxic compounds in wastewater can cause problems for organic matter and nutrient removal. In this study, the long term effect of a model xenobiotic, 2-fluorophenol (2-FP), on ammonia oxidizing bacteria (AOB), nitrite oxidizing bacteria (NOB) and phosphate accumulating organisms (PAO) in aerobic granular sludge was investigated. Phosphate (P) and ammonium (N) removal efficiencies were high (>93%) and, after bioaugmentation with 2-FP degrading strain FP1, 2-FP was completely degraded. Neither N nor P removal were affected by 50 mg L−1 of 2-FP in the feed stream. Changes in the aerobic granule bacterial communities were followed. Numerical analysis of the denaturing gradient gel electrophoresis (DGGE) profiles showed low diversity for the amoA gene with an even distribution of species. PAOs, including denitrifying PAO (dPAO), and AOB were present in the 2-FP degrading granules, although dPAO population decreased throughout the 444 days reactor operation. The results demonstrated that the aerobic granules bioaugmented with FP1 strain successfully removed N, P and 2-FP simultaneously.


2006 ◽  
Vol 53 (9) ◽  
pp. 63-70 ◽  
Author(s):  
X. Wang ◽  
M. Ji ◽  
J.F. Wang ◽  
Z. Liu ◽  
Z.Y. Yang

An unusual phenomenon of anaerobic phosphate uptake under alternating anaerobic/aerobic condition was observed in a granular sludge sequencing batch reactor, fed with acetate as sole organic substrate. Anaerobic phosphate uptake efficiencies remained at 50–70% as the influent P/COD was increased from 2/100 to 4/100, and results showed that anaerobic uptake of phosphate was correlated with anaerobic absorption of acetate. Excluding the main possibility of chemical phosphate removal, it appeared that phosphate uptake during the anaerobic phase was associated with organisms enriched in the reactor. Moreover, results indicated that intracellular glycogen was used as the main energy source of organics anaerobic absorption and intracellular polymers storage. Measuring and analysing the variation of phosphate, organic substrate, intracellular glycogen and pH in the anaerobic phase, a preliminary explanation was developed that anaerobic uptake of phosphate was the demand of intracellular glycogen degradation, and extracellular phosphate was transported to intracellular by pH gradient-sensitive phosphate carrier protein.


2012 ◽  
Vol 109 (8) ◽  
pp. 1919-1928 ◽  
Author(s):  
J.P. Bassin ◽  
M.-K.H. Winkler ◽  
R. Kleerebezem ◽  
M. Dezotti ◽  
M.C.M. van Loosdrecht

2011 ◽  
Vol 77 (22) ◽  
pp. 7942-7953 ◽  
Author(s):  
J. P. Bassin ◽  
M. Pronk ◽  
G. Muyzer ◽  
R. Kleerebezem ◽  
M. Dezotti ◽  
...  

ABSTRACTThe long- and short-term effects of salt on biological nitrogen and phosphorus removal processes were studied in an aerobic granular sludge reactor. The microbial community structure was investigated by PCR-denaturing gradient gel electrophoresis (DGGE) on 16S rRNA andamoAgenes. PCR products obtained from genomic DNA and from rRNA after reverse transcription were compared to determine the presence of bacteria as well as the metabolically active fraction of bacteria. Fluorescencein situhybridization (FISH) was used to validate the PCR-based results and to quantify the dominant bacterial populations. The results demonstrated that ammonium removal efficiency was not affected by salt concentrations up to 33 g/liter NaCl. Conversely, a high accumulation of nitrite was observed above 22 g/liter NaCl, which coincided with the disappearance ofNitrospirasp. Phosphorus removal was severely affected by gradual salt increase. No P release or uptake was observed at steady-state operation at 33 g/liter NaCl, exactly when the polyphosphate-accumulating organisms (PAOs), “CandidatusAccumulibacter phosphatis” bacteria, were no longer detected by PCR-DGGE or FISH. Batch experiments confirmed that P removal still could occur at 30 g/liter NaCl, but the long exposure of the biomass to this salinity level was detrimental for PAOs, which were outcompeted by glycogen-accumulating organisms (GAOs) in the bioreactor. GAOs became the dominant microorganisms at increasing salt concentrations, especially at 33 g/liter NaCl. In the comparative analysis of the diversity (DNA-derived pattern) and the activity (cDNA-derived pattern) of the microbial population, the highly metabolically active microorganisms were observed to be those related to ammonia (Nitrosomonassp.) and phosphate removal (“CandidatusAccumulibacter”).


Nitrogen ◽  
2021 ◽  
Vol 2 (4) ◽  
pp. 474-490
Author(s):  
Roya Pishgar ◽  
John Albino Dominic ◽  
Joo Hwa Tay ◽  
Angus Chu

This study investigated structural changes in microbial community of biological nutrient removal (BNR) in response to changes in substrate composition (ammonium and phosphate), redox condition, and morphological characteristics (flocs to granules), with a focus on nitrification and phosphate removal. Analyzing treatment performance and 16S rRNA phylogenetic gene sequencing data suggested that heterotrophic nitrification (HN) and autotrophic nitrification (AN) potentially happened in aerobic organic-rich (HN_AS) and aerobic organic-deficient (AN_AS) activated sludge batch reactors, respectively. However, phosphate release and uptake were not observed under alternating anaerobic/aerobic regime. Phosphate release could not be induced even when anaerobic phase was extended, although Accumulibacter existed in the inoculum (5.1% of total bacteria). Some potential HN (e.g., Thauera, Acinetobacter, Flavobacterium), AN (e.g., Nitrosomonas (3.2%) and Nitrospira), and unconventional phosphate-accumulating organisms (PAOs) were identified. Putative HN bacteria (i.e., Thauera (29–36%) and Flavobacterium (18–25%)) were enriched in aerobic granular sludge (AGS) regardless of the granular reactor operation mode. Enrichment of HN organisms in the AGS was suspected to be mainly due to granulation, possibly due to the floc-forming ability of HN species. Thus, HN is likely to play a role in nitrogen removal in AGS reactors. This study is supposed to serve as a starting point for the investigation of the microbial communities of AS- and AGS-based BNR processes. It is recommended that the identified roles for the isolated bacteria are further investigated in future works.


2017 ◽  
Vol 77 (4) ◽  
pp. 1107-1114 ◽  
Author(s):  
Benjamin J. Thwaites ◽  
Ben van den Akker ◽  
Petra J. Reeve ◽  
Michael D. Short ◽  
Nirmala Dinesh ◽  
...  

Abstract The successful development of aerobic granular sludge (AGS) for secondary wastewater treatment has been linked to a dedicated anaerobic feeding phase, which enables key microbes such as poly-phosphate-accumulating organisms (PAOs) and glycogen-accumulating organisms to gain a competitive advantage over floc-forming organisms. The application of AGS to treat high-saline sewage and its subsequent impacts on microbial ecology, however, are less well understood. In this study, the impacts of high-saline sewage on AGS development, performance and ecology were investigated using molecular microbiology methods. Two feeding strategies were compared at pilot scale: a full (100%) anaerobic feed; and a partial (33%) anaerobic feed. The results were compared to a neighbouring full-scale conventional activated sludge (CAS) system (100% aerobic). We observed that AGS developed under decreased anaerobic contact showed a comparable formation, stability and nitrogen removal performance to the 100% anaerobically fed system. Analysis of the microbial ecology showed that the altered anaerobic contact had minimal effect on the abundances of the functional nitrifying and denitrifying bacteria and Archaea; however, there were notable ecological differences when comparing different sized granules. In contrast to previous work, a large enrichment in PAOs in AGS was not observed in high-saline wastewater, which coincided with poor observed phosphate removal performance. Instead, AGS exhibited a substantial enrichment in sulfide-oxidising bacteria, which was complemented by elemental analysis that identified the presence of elemental sulfur precipitation. The potential role for these organisms in AGS treating high-saline wastewater is discussed.


2015 ◽  
Vol 71 (3) ◽  
pp. 440-445 ◽  
Author(s):  
C. Bumbac ◽  
I. A. Ionescu ◽  
O. Tiron ◽  
V. R. Badescu

The focus of this study was to assess the treatment performance and granule progression over time within a continuous flow reactor. A continuous flow airlift reactor was seeded with aerobic granules from a laboratory scale sequencing batch reactor (SBR) and fed with dairy wastewater. Stereomicroscopic investigations showed that the granules maintained their integrity during the experimental period. Laser diffraction investigation showed proof of new granules formation with 100–500 μm diameter after only 2 weeks of operation. The treatment performances were satisfactory and more or less similar to the ones obtained from the SBR. Thus, removal efficiencies of 81–93% and 85–94% were observed for chemical oxygen demand and biological oxygen demand, respectively. The N-NH+4 was nitrified with removal efficiencies of 83–99% while the nitrate produced was simultaneously denitrified – highest nitrate concentration determined in the effluent was 4.2 mg/L. The removal efficiency of total nitrogen was between 52 and 80% depending on influent nitrogen load (39.3–76.2 mg/L). Phosphate removal efficiencies ranged between 65 and above 99% depending on the influent phosphate concentration, which varied between 11.2 and 28.3 mg/L.


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