scholarly journals Characterization of Denitrifying Phosphorus Removal Microorganisms in a Novel Two-Sludge Process by Combining Chemical with Microbial Analysis

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Haiming Zou ◽  
Xiwu Lu ◽  
Saad Abualhail
Keyword(s):  
Activated Sludge ◽  
Phosphorus Removal ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Dry Weight ◽  
P Uptake ◽  
Specific Rate ◽  
Denitrifying Phosphorus Removal ◽  
Wastewater Treatment Process ◽  
P Release ◽  
Microbial Analysis

The present work focuses on the investigation of denitrifying phosphorus removal organisms (DPB) in a novel two-sludge denitrifying phosphorus removal process by combining chemical with microbial analysis. When the two-sludge process operated stably over one year, good phosphorus (P) release and P uptake performance of activated sludge samples collected from this process were present in anaerobic and anoxic conditions, respectively, via batch test, showing that the ratio of P release specific rate to P uptake specific rate was 1.31. The analysis of energy dispersive spectrometry (EDS) showed that P content of activated sludge samples collected at the end of anoxic phase was 12.3% of dry weight, further demonstrating the existence of microorganisms responsible for phosphorus removal in this two-sludge process. From polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) analysis, the presence of microorganisms mostly belonging to the phyla Firmicutes and Proteobacteria was observed, previously evidenced in the phosphorus removal wastewater treatment process. Fluorescence in situ hybridization (FISH) quantitative analysis showed thatAccumulibacterresponsible for phosphorus removal was dominant in this two-sludge process, accounting for 69.7% of all bacteria in activated sludge. These results obtained from chemical and microbial analysis in this study suggested that denitrifying phosphorus removal microorganisms were completely enriched in the two-sludge process proposed here.

Analysis of phosphorus removal and anaerobic selector performance in a full-scale activated sludge process in Singapore

2006 ◽  
Vol 54 (8) ◽  
pp. 237-246 ◽  
Author(s):  
Y.S. Cao ◽  
C.M. Ang ◽  
K.S. Raajeevan ◽  
A.K. Kiran ◽  
K.C. Lai ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Phosphorus Removal ◽  
Volatile Fatty Acids ◽  
P Uptake ◽  
Full Scale ◽  
Volume Index ◽  
Activated Sludge Process ◽  
Biological Phosphorus Removal ◽  
P Release ◽  
Sludge Settleability

This paper analyses the performance of the anaerobic selector (A/O process) in a full-scale activated sludge process receiving mostly industrial sewage discharge (>60%) in Singapore. In addition to the sludge settleability, enhanced biological phosphorus removal (EBPR) was studied. The sludge volume index (SVI) reduced from 200 to 80 ml g−1 and foaming was suppressed significantly, indicating the effectiveness of the anaerobic selector in improving sludge settleability. The phosphorus removal efficiency was 66%, and 7.5 mg HAc-COD was consumed per mg PO3−4-P removed. In the anaerobic compartment, 31% of the SCOD and 73% of the acetic acid in the settled sewage were removed with PO3−4-P release of 14.1 mg PO3−4-P l −1. The linear correlation between PO3−4-P release in the anaerobic compartment and PO3−4-P uptake in the aerobic compartment indicates that there is about 0.8 mg PO3−4-P release in the anaerobic compartment per mg PO3−4-P uptake in the aerobic compartment. The fates of volatile fatty acids (VFAs) and its short chain acids (SCAs) in the process were studied and discussed.

Denitrification kinetics in biological N and P removal activated sludge systems treating municipal wastewaters

1999 ◽  
Vol 39 (6) ◽  
pp. 69-77 ◽  
Author(s):  
George A. Ekama ◽  
Mark C. Wentzel
Keyword(s):  
Activated Sludge ◽  
Phosphorus Removal ◽  
P Uptake ◽  
Active Fraction ◽  
Batch Tests ◽  
P Release ◽  
Denitrification Kinetics ◽  
Nd Systems ◽  
Activated Sludge Systems ◽  
P Removal

The denitrification kinetics at 12, 20 and 30°C in nitrification denitrification biological excess phosphorus removal (NDBEPR) systems were delineated in batch tests on sludge harvested from laboratory scale M/UCT systems. In some investigations, it was found that the P release and uptake were confined exclusively (>95%) to the anaerobic and aerobic reactors respectively and the observed P removal conformed to the BEPR model of Wentzel et al. In these investigations, due to an absence of anoxic P uptake (substantiated by PHB measurements), it could be inferred that the phosphate accumulating organisms (PAOs) did not significantly contribute to the denitrification. The ordinary heterotrophic organism (OHO) and PAO groups were separated with the aid of the BEPR model of Wentzel et al. Ascribing the denitrification to the OHO group performing this process, the specific rates of denitrification associated with the utilization of slowly biodegradable COD (SBCOD) in the primary (K′2) and secondary (K′3) anoxic reactors were calculated and compared with the rates in ND systems (K2 and K3). In other investigations it was found that P release and uptake were not confined exclusively to the anaerobic and aerobic reactors respectively and the observed P removal was only about 60% of that expected from the BEPR model of Wentzel et al. In these investigations significant P uptake under anoxic conditions was observed so the PAOs may have been involved with the denitrification. However, the denitrification rates were calculated as before by attributing it exclusively to the OHOs. Widely varying K'2 rates were observed at 20°C, ranging from 0.071 to 0.335 mgNO3-N/(mgAHVSS.d). The variation in K' rate is mainly due to widely varying OHO active fraction estimates for NDBEPR systems.

Combined denitrification and excess biological phosphorus removal in discontinuous operated biofilm systems

2002 ◽  
Vol 46 (4-5) ◽  
pp. 193-200 ◽  
Author(s):  
D. Brandt ◽  
C. Sieker ◽  
W. Hegemann
Keyword(s):  
Phosphorus Removal ◽  
P Uptake ◽  
Organic Substrate ◽  
Treated Wastewater ◽  
Biological Phosphorus Removal ◽  
P Release ◽  
Different Types ◽  
Immobilized Biomass ◽  
Biological Phosphorus ◽  
P Removal

The sorption-denitrification-P-removal (S-DN-P) process combines biological excess P-removal (BEPR) and denitrification using immobilized biomass. The accumulation of denitrifying polyP organisms is achieved by sequencing anaerobic/anoxic conditions. The immobilized biomass is in alternating contact with primary treated wastewater (anaerobic sorption-phase) and nitrified wastewater (denitrification phase). In the sorption phase, P-release takes place and readily biodegradable organic substrate, e.g. volatile fatty acid, is taken up and stored by polyP accumulating organisms (PAO). In addition to this, other organic matter is physically/chemically adsorbed in the biofilm structures. In the denitrification phase, the biomass denitrifies the stored and adsorbed organic substrate and, at the same time, P-uptake and polyP formation occurs. This paper presents results of investigations at laboratory and half-technical scale. At laboratory scale different types of carriers were tested regarding their suitability for the S-DN-P-process. In half-technical scale a biofilter and a moving bed reactor (MBR) were tested. In the biofilter a stable removal of nitrate and phosphate was achieved. However, it was not possible to achieve similar results in the MBR process. Especially the release and uptake of phosphate showed no clear tendency although the uptake of acetate was good. Reasons for this could be the accumulation of glycogen accumulating organisms which impair the metabolism of PAO.

Effect of continuous addition of an organic substrate to the anoxic phase on biological phosphorus removal

1998 ◽  
Vol 38 (1) ◽  
pp. 97-105 ◽  
Author(s):  
J. Meinhold ◽  
H. Pedersen ◽  
E. Arnold ◽  
S. Isaacs ◽  
M. Henze
Keyword(s):  
Phosphorus Removal ◽  
Phosphate Uptake ◽  
P Uptake ◽  
Organic Substrate ◽  
Organic Substrates ◽  
Biological Phosphorus Removal ◽  
P Release ◽  
Influence Of Substrate ◽  
Biological Phosphorus ◽  
P Removal

The continuous introduction of a biological phosphorus removal (BPR) promoting organic substrate to the denitrifying reactor of a BPR process is examined through a series of batch experiments using acetate as model organic substrate. Several observations are made regarding the influence of substrate availability on PHA storage/utilization and phosphate uptake/release. Under anoxic conditions PHB is utilized and phosphate is taken up, indicating that at least a fraction of the PAO can denitrify. The rates of anoxic P-uptake, PHB utilization and denitrification are found to increase with increasing initial PHB level. At low acetate addition rates the P-uptake and PHB utilization rates are reduced compared to when no acetate is available. At higher acetate addition rates a net P-release occurs and PHB is accumulated. For certain intermediate acetate addition rates the PHB level can increase while a net P-release occurs. Whether the introduction of BPR promoting organic substrates to the denitrifying reactor is detrimental to overall P-removal appears to be dependent on the interaction between aerobic P-uptake, which is a function of PHB level, and the aerobic residence time.

Comparison of aerobic and anoxic phosphorus uptake in ndbepr systems (uct and enbnras)

2002 ◽  
Vol 46 (4-5) ◽  
pp. 201-207 ◽  
Author(s):  
S.M. Vermande ◽  
S. Sötemann ◽  
G. Aguilera Soriano ◽  
M. Wentzel ◽  
J.M. Audic ◽  
...  
Keyword(s):  
Nutrient Removal ◽  
Phosphorus Removal ◽  
Mass Fraction ◽  
Phosphorus Uptake ◽  
P Uptake ◽  
Biological Nutrient Removal ◽  
P Release ◽  
University Of Cape Town ◽  
The University ◽  
P Removal

Two Nitrification-Denitrification Biological Excess Phosphorus Removal (NDBEPR) systems have been operated for 8.5 months in order to compare their Biological Excess Phosphorus Removal (BEPR) performance. One of these systems, i.e. the University of Cape Town (UCT) system, exhibits mainly aerobic P uptake while the External Nitrification Biological Nutrient Removal Activated Sludge (ENBNRAS) system is characterised by high anoxic P uptake. It was observed that when operating with predominantly aerobic P uptake, the UCT system released more P than the ENBNRAS system, even though it had a lower anaerobic mass fraction. However, when the influent TKN/COD was high, i.e. >0.1, anoxic P uptake also occurred in the UCT system and P release dropped to lower levels than in the ENBNRAS. Accordingly, P uptake of the UCT system was 5 mg P/l influent higher than that of the ENBNRAS system, when it was predominantly aerobic, but 9 mg P/l influent lower when anoxic P uptake occurred. As a result, the UCT system achieved superior P removal when aerobic P uptake was predominant (23% higher), but when high influent TKN/COD promoted anoxic P uptake the P removal of the UCT system was poorer than that of the ENBNRAS system. This study clearly showed that anoxic P uptake is not beneficial to NDBEPR systems.

scholarly journals Ecological Insights Into Community Interactions, Assembly Processes and Function in the Denitrifying Phosphorus Removal Activated Sludge Driven by Phosphorus Sources

2021 ◽  
Vol 12 ◽  
Author(s):  
Lei Zheng ◽  
Xue Wang ◽  
Aizhong Ding ◽  
Dongdan Yuan ◽  
Qiuyang Tan ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Phosphorus Removal ◽  
Species Interactions ◽  
Pollutant Removal ◽  
Available Phosphorus ◽  
Community Interactions ◽  
Denitrifying Phosphorus Removal ◽  
Α Diversity ◽  
Phosphorus Sources ◽  
Phosphorus Source

The microbial characteristics in the wastewater treatment plants (WWTPs) strongly affect their optimal performance and functional stability. However, a cognitive gap remains regarding the characteristics of the microbial community driven by phosphorus sources, especially co-occurrence patterns and community assembly based on phylogenetic group. In this study, 59 denitrifying phosphorus removal (DPR) activated sludge samples were cultivated with phosphorus sources. The results suggested that homogeneous selection accounted for the largest proportion that ranged from 35.82 to 64.48%. Deterministic processes dominated in 12 microbial groups (bins): Candidatus_Accumulibacter and Pseudomonas in these bins belonged to phosphate-accumulating organisms (PAOs). Network analysis revealed that species interactions were intensive in cyclic nucleoside phosphate-influenced microbiota. Function prediction indicated that cyclic nucleoside phosphates increased the activity of enzymes related to denitrification and phosphorus metabolism and increased the α-diversity of microorganism but decreased the diversity of metabolic function. Based on these results, it was assumed that cyclic nucleoside phosphates, rather than inorganic phosphates, are the most available phosphorus source for majority microorganisms in DPR activated sludge. The study revealed the important role of phosphorus source in the construction and assembly of microbial communities and provided new insights about pollutant removal from WWTPs.

Analysis of microbial community that performs enhanced biological phosphorus removal in activated sludge fed with acetate

2002 ◽  
Vol 46 (1-2) ◽  
pp. 145-154 ◽  
Author(s):  
M. Onuki ◽  
H. Satoh ◽  
T. Mino
Keyword(s):  
Microbial Community ◽  
Activated Sludge ◽  
Phosphorus Removal ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Batch Reactor ◽  
Phosphate Removal ◽  
Enhanced Biological Phosphorus Removal ◽  
Biological Phosphorus Removal ◽  
Dominant Band ◽  
Biological Phosphorus

Enhanced biological phosphorus removal (EBPR) activated sludge was operated in a laboratory-scale sequencing batch reactor (SBR) fed with acetate as the sole carbon source. The microbial community of the sludge was analyzed using the polymerase chain reaction (PCR) – denaturing gradient gel electrophoresis (DGGE) method for about 2 months of start-up period. As a result, the number of major bands decreased during the enrichment, indicating that the microbial community structure was getting simpler. Since the phosphate removal activity was maintained at a high level, the bacteria which still remained at the end can be considered as the important bacteria playing key roles in the present EBPR sludge, maybe polyphosphate accumulating organisms (PAOs). The dominant band in the last sample on the DGGE gel was excised and the DNA recovered from it was sequenced. The sequence was closely related to one of the putative PAOs group which Crocetti et al. (2000) and Hesselmann et al. (1999) have proposed. This PAOs group is closely related to the Rhodocyclus group (b-Proteobacteria). The fluorescence in situ hybridization (FISH) method with the probe specific for this PAOs group and the DAPI staining at a phosphate-probing concentration indirectly showed that these Rhodocyclus related bacteria really accumulated polyphosphate.

Enhanced biological phosphorus removal in the retrofitting from an anoxic selector to an anaerobic selector in a full-scale activated sludge process in Singapore

2009 ◽  
Vol 59 (5) ◽  
pp. 857-865 ◽  
Author(s):  
Y. Cao ◽  
C. M. Ang ◽  
K. C. Chua ◽  
F. W. Woo ◽  
H. Chi ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Phosphorus Removal ◽  
Oxygen Demand ◽  
P Uptake ◽  
Full Scale ◽  
Activated Sludge Process ◽  
Enhanced Biological Phosphorus Removal ◽  
Biological Phosphorus Removal ◽  
Biological Phosphorus ◽  
Final Effluent

This paper presents the investigation results of retrofitting an anoxic selector to an anaerobic selector through stepwise reduction of air supply in a full-scale activated sludge process with a focus on enhanced biological phosphorus removal (EBPR). The process experienced gradual shift from a Ludzack-Ettinger (LE) to an anaerobic-anoxic-oxic (A2O) process and subsequently, an anaerobic-oxic (A/O) process. The major findings are: (i) the average influent-based PO43−-P release in the anaerobic selector compartment was 16.3 mg P l−1 and that in the secondary clarifier was 1.7 mg P l−1. 75% of the SCOD and 93% of the acetic acid in the primary effluent were taken up in the anaerobic selector compartment, respectively; (ii) PO43−-P uptake contributed by both aerobic and denitrifying phosphorus accumulating organisms (DPAOs) occurred mainly in the first and second aerobic lanes together with simultaneous nitrification and denitrification (SND) while there was not much contribution from the last aerobic lane; (iii) The average PO43−-P concentration of the final effluent was 2.4 mg P l−1 corresponding to a removal efficiency of 85%; (iv) the SVI was satisfactory after retrofitting; and (v) the increase of NH4+-N in the final effluent from the commencement to the completion of the retrofitting resulted in an approximate 40–50% reduction in oxygen demand and a significant aeration energy saving was achieved.

Biological nutrient removal in membrane bioreactors: denitrification and phosphorus removal kinetics

2007 ◽  
Vol 56 (6) ◽  
pp. 125-134 ◽  
Author(s):  
V. Parco ◽  
G. du Toit ◽  
M. Wentzel ◽  
G. Ekama
Keyword(s):  
Activated Sludge ◽  
Nutrient Removal ◽  
Phosphorus Removal ◽  
Biological Nutrient Removal ◽  
Specific Rate ◽  
Mixed Liquor ◽  
Batch Tests ◽  
The Impact ◽  
Substrate Concentrations ◽  
P Removal

The impact of including membranes for solid liquid separation on the kinetics of nitrogen and phosphorus removal was investigated. To achieve this, a membrane bioreactor (MBR) biological nutrient removal (BNR) activated sludge system was operated. From batch tests on mixed liquor drawn from the MBR BNR system, denitrification and phosphorus removal rates were delineated. Additionally the influence of the high total suspended solids concentrations present in the MBR BNR system and of the limitation of substrate concentrations on the kinetics was investigated. Moreover the ability of activated sludge in this kind of system to denitrify under anoxic conditions with simultaneous phosphate uptake was verified and quantified. The denitrification rates obtained for different mixed liquor (ML) concentrations indicate no effect of ML concentration on the specific denitrification rate. The denitrification took place at a single specific rate (K2) with respect to the ordinary heterotrophic organisms (OHOs, i.e. non-PAOs) active mass. Similarly, results have been obtained for the P removal process kinetics: no differences in specific rates were observed for different ML or substrate concentrations. From the P removal batch tests results it seems that the biological phosphorus removal population (PAO) consists of 2 different sets of organisms denitrifying PAO and aerobic PAO.

Dynamic modelling of enhanced biological phosphorus and nitrogen removal in activated sludge systems

1998 ◽  
Vol 38 (1) ◽  
pp. 203-210
Author(s):  
M. Maurer ◽  
W. Gujer
Keyword(s):  
Activated Sludge ◽  
Phosphorus Removal ◽  
Dynamic Modelling ◽  
Energy Yield ◽  
Biological Phosphorus Removal ◽  
Batch Experiments ◽  
P Release ◽  
Biological Phosphorus ◽  
Activated Sludge Systems ◽  
Model Approach

A dynamic model for the description of enhanced biological phosphorus removal is presented. Model approach and structure were mainly adopted from the “Activated Sludge Model (ASM) No 2”. Two additional processes for the anoxic growth of phosphorus accumulating organisms (PAO) and anoxic storage of polyphosphate were included. The model was further enhanced with three processes describing biologically induced phosphorus precipitation. Stoichiometric coefficients for anoxic conditions are modified under the consideration of a 35% reduction of energy yield compared with oxygen as electron acceptor. In addition, a ratio for the anaerobic P-release per substrate taken-up is introduced, which depends on pH, glycogen and substrate. With the aid of 18 batch-experiments and measurements from a WWT pilot plant, a set of kinetic parameter was estimated, that was able to reproduce satisfactorily the nutrient removal behaviour of the investigated sludge.

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