FOG, not just for co-digestion: An evaluation of primary sludge and grease trap waste fermentation for a nutrient removal 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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Enhanced biological nutrient removal in a simultaneous fermentation, denitrification and phosphate removal reactor using primary sludge as internal carbon source

Chemosphere ◽

10.1016/j.chemosphere.2012.12.071 ◽

2013 ◽

Vol 91 (5) ◽

pp. 635-640 ◽

Cited By ~ 31

Author(s):

Liang Zhang ◽

Shujun Zhang ◽

Shuying Wang ◽

Chengcheng Wu ◽

Yinguang Chen ◽

...

Keyword(s):

Carbon Source ◽

Nutrient Removal ◽

Phosphate Removal ◽

Biological Nutrient Removal ◽

Primary Sludge

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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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Denitritation of reject water using primary sludge as organic substrate

Water Practice & Technology ◽

10.2166/wpt.2007.007 ◽

2007 ◽

Vol 2 (1) ◽

Author(s):

P. Jenicek ◽

P. Svehla ◽

J. Zabranska ◽

M. Dohanyos ◽

J. Vondrysova

Keyword(s):

Water Treatment ◽

Carbon Source ◽

Nutrient Removal ◽

Biological Treatment ◽

Treatment Process ◽

Organic Substrate ◽

Primary Sludge ◽

Reject Water ◽

Water Treatment Process ◽

Biological Methods

The new biological methods of separate reject water treatment became progressive tools to optimization of nutrient removal in wastewater treatment. The method of nitritation and denitritation is one of them. The drawback of the method in comparison with technologies based on autotrophic deammonification is higher requirements for organic substrate. The possibility to suppress the drawback is the use of primary sludge as internal carbon source for denitritation. The experience with such design of separate reject water treatment process is described. The presented results confirm the possibility of efficient, stable and economical removal of nitrogen from reject water by separate biological treatment using nitritation and denitritation process and using primary sludge as the additional carbon source.

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