Aeration of anaerobically digested sewage sludge for COD and nitrogen removal: optimization at large-scale

2008 ◽  
Vol 57 (2) ◽  
pp. 257-264 ◽  
Author(s):  
V. Parravicini ◽  
K. Svardal ◽  
R. Hornek ◽  
H. Kroiss
Keyword(s):  
Wastewater Treatment ◽  
Anaerobic Digestion ◽  
Sewage Sludge ◽  
Nitrogen Removal ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Process Conditions ◽  
Nitrite Accumulation ◽  
Digested Sludge ◽  
Digested Sewage Sludge

The paper will report about the experiences at an Austrian large wastewater treatment plant of 720,000 population equivalents, where anaerobically digested sewage sludge is further stabilised under aerobic conditions. Enhanced stabilisation of the anaerobically digested sludge was required at the plant in order to get a permit for landfill disposal of the dewatered stabilized sludge. By implementing a post-aeration treatment (SRT ∼ 6d; 36 °C) after anaerobic digestion the organic content of the anaerobically well digested sludge can be decreased by 16%. Investigations on site showed that during digested sludge post-aeration anoxic phases for denitrification are needed to provide stable process conditions. In this way the pH value can be kept in a more favourable range for micro-organisms and concrete structures. Additionally, inhibition of the biological process due to nitrite accumulation can be avoided. By optimising the aeration/pause ratio ∼ 45% of total nitrogen in digested sludge can be removed. This significantly improves nitrogen removal efficiency at the wastewater treatment plant. NH4-removal occurs mainly through nitritation and denitritation with an efficiency of 98%. The costs/benefit analysis shows that post-aeration of digested sludge results in an increase of total annual costs for wastewater treatment of only 0.84%, corresponding to 0.19 Euro/pe/a. Result of molecular biological analyses (DGGE) indicate that all four ammonium-oxidizing bacteria species present in activated sludge can survive anaerobic digestion, but only two of them can adapt in the digested sludge post-aeration tanks. Additionally, in the post-aerated digested sludge a further ammonium-oxidizing bacteria species was identified.

Post-aeration of anaerobically digested sewage sludge for advanced COD and nitrogen removal: results and cost-benefit analysis at large-scale

2008 ◽  
Vol 57 (7) ◽  
pp. 1087-1094 ◽  
Author(s):  
V. Parravicini ◽  
K. Svardal ◽  
H. Kroiss
Keyword(s):  
Wastewater Treatment ◽  
Sewage Sludge ◽  
Nitrogen Removal ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Process Conditions ◽  
Nitrite Accumulation ◽  
Benefit Analysis ◽  
Digested Sludge ◽  
Digested Sewage Sludge

At a large Austrian municipal wastewater treatment plant enhanced stabilisation of anaerobically digested sewage sludge was required in order to get a permit for landfill disposal of the dewatered stabilized sludge. By implementing a post-aeration treatment after anaerobic digestion the organic content of the anaerobically well digested sludge can be decreased by 16%. Investigations at this plant showed that during digested sludge post-aeration anoxic phases are needed to provide stable process conditions. In this way the pH value can be kept in a more favourable range for micro-organisms and concrete structures. Additionally, under the process conditions applied nitrite accumulation would inhibit the stabilisation process if denitrification is not adequately applied. By optimising the aeration/pause ratio ∼45% of total nitrogen in digested sludge can be removed. NH4-removal occurs through nitritation and denitritation with an efficiency of 98%. This significantly improves nitrogen removal efficiency at the wastewater treatment plant. The costs/benefit analysis shows that post-aeration of digested sludge results in an increase of total annual costs for wastewater treatment of only 0.84%, corresponding to 0.19 Euro/pe/a. Specific costs for nitrogen removal (0.32 Euro/kgN) are comparable with other biological processes for N-removal in reject water.

Potentials and limits of anaerobic digestion of sewage sludge: Energy self-sufficient municipal wastewater treatment plant?

2012 ◽  
Vol 66 (6) ◽  
pp. 1277-1281 ◽  
Author(s):  
P. Jenicek ◽  
J. Bartacek ◽  
J. Kutil ◽  
J. Zabranska ◽  
M. Dohanyos
Keyword(s):  
Wastewater Treatment ◽  
Energy Consumption ◽  
Anaerobic Digestion ◽  
Sewage Sludge ◽  
Wastewater Treatment Plant ◽  
Municipal Wastewater ◽  
Biogas Production ◽  
Treatment Plant ◽  
Self Sufficiency ◽  
Digestion Efficiency

Anaerobic digestion is the only energy-positive technology widely used in wastewater treatment. Full-scale data prove that the anaerobic digestion of sewage sludge can produce biogas that covers a substantial amount of the energy consumption of a wastewater treatment plant (WWTP). In this paper, we discuss possibilities for improving the digestion efficiency and biogas production from sewage sludge. Typical specific energy consumptions of municipal WWTPs per population equivalent are compared with the potential specific production of biogas to find the required/optimal digestion efficiency. Examples of technological measures to achieve such efficiency are presented. Our findings show that even a municipal WWTP with secondary biological treatment located in a moderate climate can come close to energy self-sufficiency. However, they also show that such self-sufficiency is dependent on: (i) the strict optimization of the total energy consumption of the plant, and (ii) an increase in the specific biogas production from sewage sludge to values around 600 L per kg of supplied volatile solids.

A study of the digestion process of sewage sludge from a dairy wastewater treatment plant to determine the composition and load of reject water

2014 ◽  
Vol 9 (1) ◽  
pp. 71-78 ◽  
Author(s):  
W. Da˛browski
Keyword(s):  
Wastewater Treatment ◽  
Anaerobic Digestion ◽  
Sewage Sludge ◽  
Wastewater Treatment Plant ◽  
Research Work ◽  
Treatment Plant ◽  
Ammonia Nitrogen ◽  
Dairy Wastewater ◽  
High Concentration ◽  
Reject Water

The issue of reject water has to be considered in almost every biological municipal or industrial wastewater treatment plant (WWTP) that applies aerobic or anaerobic digestion of sewage sludge. Reject water is usually returned to the beginning of the treatment process, which results in periodical disturbances in stable and efficient sewage treatment. Due to planned modernization of one of the biggest dairy WWTPs in Poland, a laboratory scale research has been carried out to determine quality characteristics of reject water. Aerobic and anaerobic digestion was applied to a mixture of two kinds of sludge: excessive and flotation. According to research performed by the author results (range value) of reject water were: 7.3 to 12.9 mg N-NH4/L after aerobic and 460.0 to 574.0 mg N-NH4/L after anaerobic digestion. The study has confirmed a higher value of organic substances in reject water after anaerobic digestion in comparison with aerobic. Due to high concentration of ammonia nitrogen in reject water obtained during co-digestion of excessive and flotation sludge, a separated system for its treatment should be applied. The results of research work presented in this paper provided a base for the project of the pilot installation with constructed wetland.

EVALUATION OF BIOMETHANE YIELDS FROM HIGH-ENERGY ORGANIC WASTE AND SEWAGE SLUDGE: A PILOT STUDY FOR A WASTEWATER TREATMENT PLANT

2019 ◽  
Vol 18 (9) ◽  
pp. 2023-2034 ◽  
Author(s):  
Agnieszka A. Pilarska ◽  
Krzysztof Pilarski ◽  
Boguslawa Waliszewska ◽  
Magdalena Zborowska ◽  
Kamil Witaszek ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Pilot Study ◽  
Sewage Sludge ◽  
Wastewater Treatment Plant ◽  
Organic Waste ◽  
Treatment Plant ◽  
High Energy

Sludge minimization by disintegration at different wastewater treatment plants

2008 ◽  
Vol 3 (1) ◽  
Author(s):  
Luchien Luning ◽  
Paul Roeleveld ◽  
Victor W.M. Claessen
Keyword(s):  
Organic Matter ◽  
Wastewater Treatment ◽  
Anaerobic Digestion ◽  
Sewage Sludge ◽  
New Technologies ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Biological Degradation ◽  
Ongoing Research ◽  
Sludge Minimization

In recent years new technologies have been developed to improve the biological degradation of sewage sludge by anaerobic digestion. The paper describes the results of a demonstration of ultrasonic disintegration on the Dutch Wastewater Treatment Plant (WWTP) Land van Cuijk. The effect on the degradation of organic matter is presented, together with the effect on the dewatering characteristics. Recommendations are presented for establishing research conditions in which the effect of sludge disintegration can be determined in a more direct way that is less sensitive to changing conditions in the operation of the WWTP. These recommendations have been implemented in the ongoing research in the Netherlands supported by the National Institute for wastewater research (STOWA).

Operational Results of the Wolfsburg Wastewater Treatment Plant

1992 ◽  
Vol 25 (4-5) ◽  
pp. 203-209 ◽  
Author(s):  
R. Kayser ◽  
G. Stobbe ◽  
M. Werner
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Nitrogen Content ◽  
Total Nitrogen ◽  
Nitrogen Removal ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Phosphate Removal ◽  
Total Nitrogen Content ◽  
Activated Sludge Process

At Wolfsburg for a load of 100,000 p.e., the step-feed activated sludge process for nitrogen removal is successfully in operation. Due to the high denitrification potential (BOD:TKN = 5:1) the effluent total nitrogen content can be kept below 10 mg l−1 N; furthermore by some enhanced biological phosphate removal about 80% phosphorus may be removed without any chemicals.

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