Enhanced biological nutrient removal in a simultaneous fermentation, denitrification and phosphate removal reactor using primary sludge as internal carbon source

Biological nutrient removal requires sufficient carbon source. Meanwhile, the removal of organic matter in wastewater requires energy consumption in the aeration tank. Carbon source for nutrient removal in most wastewater treatment plants with conventional primary clarifier (CPC) is generally insufficient in China. In order to increase carbon source and to save energy, a part of the CPC may be retrofitted as an activated primary clarifier (APC). In this paper, a pilot scale experiment was conducted to examine the performance of primary sludge fermentation and its effect on nitrogen and phosphorus removal. Results show that the primary sludge fermentation in APC has produced a similar VFA/TP ratio but a higher BOD5/TN ratio compared with those in the CPC effluent, and the TN concentrations in the secondary effluent are at 8.0, 10.8, and 17.4 mg/L, while TP is at 0.45, 1.10, and 2.28 mg/L when the pilot test system was fed with (1) the APC effluent, (2) 50% from the APC effluent and 50% from the CPC effluent, and (3) the CPC effluent, respectively. Results also indicate that the BOD5/TN ratio is a more sensitive factor than the VFA/TP ratio for nutrient removal and energy conservation for the APC fermentation.

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Primary sludge hydrolysis for biological nutrient removal

Water Science & Technology ◽

10.2166/wst.1996.0399 ◽

1996 ◽

Vol 34 (1-2) ◽

pp. 417-423 ◽

Cited By ~ 12

Author(s):

G. J. Hatziconstantinou ◽

P. Yannakopoulos ◽

A. Andreadakis

Keyword(s):

Carbon Source ◽

Nutrient Removal ◽

Continuous Flow ◽

Hydraulic Retention Time ◽

Pilot Scale ◽

Biological Nutrient Removal ◽

Primary Sludge ◽

Carbon Production ◽

Sludge Hydrolysis ◽

Removal Processes

Primary sludge hydrolysis can enrich primary effluent with the soluble organics which in turn can be a valuable carbon source to subsequent nutrient removal processes. By controlling hydraulic retention time and temperature it is possible to confine the anaerobic digestion of the primary sludge to the acidogenic and acetogenic phase (hydrolysis/fermentation process), and take advantage of the soluble organics produced. This paper presents the results of a research involving bench and pilot scale experiments related to primary sludge hydrolysis. The pilot scale sedimentation tank (4.10 m in diameter, 3.20 m in depth) operated over an expended period of 21 months as a conventional clarifier and following this as a fermentor unit employing sludge recirculation. Parallel to the pilot scale experiments, several batch and continuous flow bench scale experiments were conducted in order to determine the factors controlling the production of soluble organics and the effect of the latter on the denitrification process. The conclusions drawn were that a) a soluble COD production of the order of 5-6% in terms of sludge TCOD can be expected in a batch fermentor operating with HRT≅2days at T≤ 20°C, b) in a continuous flow fermentor, combinations of T>20°C and SRT>2 should be applied in order to achieve a production of the order of 10%, c) significant soluble carbon production can be achieved in primary sedimentation tanks (over 30% in terms of influent SCOD) when relatively increased SRTs (4 to 5 days) in combination with sludge recirculation are employed, under T>22°C, and d) increased denitrification performance of the order of 9 mgNOx/g MLSS.hr, can be achieved with hydrolysate as a carbon source.

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Survey of filamentous populations in nutrient removal plants in four European countries

Water Science & Technology ◽

10.2166/wst.1998.0645 ◽

1998 ◽

Vol 37 (4-5) ◽

pp. 281-289 ◽

Cited By ~ 26

Author(s):

Dick H. Eikelboom ◽

Andreas Andreadakis ◽

Kjaer Andreasen

Keyword(s):

Nutrient Removal ◽

Seasonal Pattern ◽

Plug Flow ◽

Phosphate Removal ◽

Particulate Fraction ◽

Biological Nutrient Removal ◽

Process Conditions ◽

Minor Importance ◽

Filamentous Microorganisms ◽

Short Period

A joint EU research project aimed at solving activated sludge bulking in nutrient removal plants was initiated in 1993. The project started with a survey of the size and composition of the filamentous population in nutrient removal plants in Denmark, Germany, Greece and the Netherlands. The results show that biological nutrient removal process conditions indeed favour filamentous microorganisms in their competition with floc forming organisms. An increase in the size of the filamentous population resulted in a deterioration of the settling properties of the biomass, except for plants with Bio-P removal conditions. It is assumed that in the latter case the dense clusters of Bio-P bacteria increase the weight of the flocs, and compensate for the effect of the larger number of filaments. Although exceptions frequently occur, the following sequence in decreasing filamentous organism population size was observed for the process conditions indicated: - completely mixed + simultaneous denitrification; - completely mixed + intermittent aeration/denitrification; - alternating anoxic/oxic process conditions, with an anaerobic tank for biological phosphate removal (Bio-Denipho); - alternating anoxic/oxic process conditions (Bio-Denitro); - predenitrification The surveys provided little information about the effect of nutrient removal in plants with plug flow aeration basins. Simultaneous precipitation with aluminium salts nearly always resulted in a low number of filaments and a good settling sludge. The size of the filamentous organism population showed a seasonal pattern with a maximum in winter/early spring and a minimum during summer (in Greece: during autumn). This seasonal variation is primarily caused by the effect of the season on the population sizes of M. parvicella, N. limicola and Type 0092. M. parvicella is by far the most important filamentous species in nutrient removal plants. In Denmark only, Type 0041 also frequently dominates the filamentous population, but seldom causes severe bulking. Considering their frequency of occurrence, approx. 10 other filamentous micro-organisms are of minor importance. Growth of some of these species, viz. those which use soluble substrate, can be prevented by the introduction of Bio-P process conditions. M. parvicella and Type 0041 (and probably also Actinomycetes and the Types 1851 and 0092) seem to compete for the same substrates i.e. the influent particulate fraction. Most of the differences in composition of the filamentous microorganism population can be explained by whether or not premixing of influent and recycled sludge is used. In general, premixing for a short period of time followed by anoxic conditions favours Type 0041. M. parvicella seems to proliferate if the particulate fraction is first hydrolysed or if it enters the plant via an oxic zone. It is concluded that bulking in nutrient removal plants is mainly caused by filamentous species requiring the particulate fraction for their growth.

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FOG, not just for co-digestion: An evaluation of primary sludge and grease trap waste fermentation for a nutrient removal carbon source.

Proceedings of the Water Environment Federation ◽

10.2175/193864714815940677 ◽

2014 ◽

Vol 2014 (16) ◽

pp. 799-807 ◽

Cited By ~ 1

Author(s):

Hunter Long ◽

Ronald Latimer ◽

Wendell Khunjar ◽

Katya Bilyk ◽

Charles Bott ◽

...

Keyword(s):

Carbon Source ◽

Nutrient Removal ◽

Primary Sludge ◽

Grease Trap Waste

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An internal carbon source for improving biological nutrient removal

Bioresource Technology ◽

10.1016/j.biortech.2008.05.023 ◽

2009 ◽

Vol 100 (1) ◽

pp. 149-154 ◽

Cited By ~ 36

Author(s):

Pantelis Kampas ◽

Simon A. Parsons ◽

Pete Pearce ◽

Sandrine Ledoux ◽

Pete Vale ◽

...

Keyword(s):

Carbon Source ◽

Nutrient Removal ◽

Biological Nutrient Removal

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Effect of carbon source on biological nutrient removal in a sequencing batch reactor

Bioresource Technology ◽

10.1016/s0960-8524(03)00031-2 ◽

2003 ◽

Vol 89 (1) ◽

pp. 89-93 ◽

Cited By ~ 41

Author(s):

F Kargi

Keyword(s):

Carbon Source ◽

Nutrient Removal ◽

Sequencing Batch Reactor ◽

Batch Reactor ◽

Biological Nutrient Removal

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Simultaneous removal of organic and strong nitrogen from sewage in a pilot-scale BNR process supplemented with food waste

Water Science & Technology ◽

10.2166/wst.2004.0762 ◽

2004 ◽

Vol 49 (5-6) ◽

pp. 257-264 ◽

Cited By ~ 8

Author(s):

S.R. Chae ◽

S.H. Lee ◽

J.O. Kim ◽

B.C. Paik ◽

Y.C. Song ◽

...

Keyword(s):

Carbon Source ◽

Food Waste ◽

Nutrient Removal ◽

Phosphorus Removal ◽

Pilot Scale ◽

Biological Nutrient Removal ◽

Biological Phosphorus Removal ◽

External Carbon Source ◽

N Removal ◽

Biological Phosphorus

As the sewerage system is incomplete, sewage in Korea lacks easily biodegradable organics for nutrient removal. In this country, about 11,400 tons of food waste of high organic materials is produced daily. Therefore, the potential of food waste as an external carbon source was examined in a pilot-scale BNR (biological nutrient removal) process for a half year. It was found that as the supply of the external carbon increased, the average removal efficiencies of T-N (total nitrogen) and T-P (total phosphorus) increased from 53% and 55% to 97% and 93%, respectively. VFAs (volatile fatty acids) concentration of the external carbon source strongly affected denitrification efficiency and EBPR (enhanced biological phosphorus removal) activity. Biological phosphorus removal was increased to 93% when T-N removal efficiency increased from 78% to 97%. In this study, several kinds of PHAs (poly-hydroxyalkanoates) in cells were observed. The observed PHAs was composed of 37% 3HB (poly-3- hydroxybutyrate), 47% 3HV (poly-3-hydroxyvalerate), 9% 3HH (poly-3-hydroxyhexanoate), 5% 3HO (poly-3-hydroxyoctanoate), and 2% 3HD (poly-3-hydroxydecanoate).

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Biological nutrient removal applied to weak sewage

Water Science & Technology ◽

10.2166/wst.1994.0578 ◽

1994 ◽

Vol 29 (12) ◽

pp. 41-48 ◽

Cited By ~ 5

Author(s):

J. Charlton

Keyword(s):

Nutrient Removal ◽

Treatment Process ◽

Treatment Plant ◽

Domestic Wastewater ◽

Biological Nutrient Removal ◽

Nitrogen And Phosphorus ◽

Primary Sludge ◽

University Of British Columbia ◽

Biological Nitrogen ◽

Influent Wastewater

The Melby Wastewater Treatment Plant is located in the municipality of Frederiksværk on the island of Sealand, Denmark. This may be the first full-scale plant in Europe purpose built for biological nutrient removal from diluted wastewater, i.e. weak domestic wastewater mixed with infiltration waters. The relatively strict effluent standards have required the existing treatment plant to be upgraded in capacity, including the design for biological Nitrogen and Phosphorus removal. Due to the weak nature of the influent wastewater, the treatment process that has been adopted includes the application of a primary sludge fermenter to alter the influent characteristics suitable for biological nutrient removal. The treatment process used is the Modified University of Cape Town process utilising a primary sludge fermenter developed at the University of British Columbia in Canada. The combination of these two processes has been successfully applied to meet the strict discharge licence requirements, without the addition of chemicals, despite the unsuitable characteristics of the influent wastewater for biological nutrient removal. The paper describes the operational results for the treatment plant.

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