TY - JOUR
T1 - Simulation assisted process simplification and energy recovery from a cryptic biological nutrient removal plant
AU - Bodur, Minel
AU - Ergin, Samet
AU - Alkay, Taner
AU - Kahraman, Seher
AU - Selvi, Ercan
AU - Ozyildiz, Goksin
AU - Karaagac, Sakine Ugurlu
AU - Cokgor, Emine
AU - Insel, Güçlü
N1 - Publisher Copyright:
© 2024 Elsevier Ltd
PY - 2024/2
Y1 - 2024/2
N2 - In this study, simulation-based analysis is conducted for nitrogen removal mechanism in a biological nutrient removal plant designed in an encrypted manner. In the first phase, the simulation study elucidates how nitrogen removal occurs in a complex design using a series of 4 carousel bioreactors with additional nitrate recycle. It is demonstrated that pre-anoxic volume fed with limited internal recirculation only would not be sufficient to meet the discharge Total Nitrogen (TN) limit of 10 mg N/L. However, the addition of simultaneous nitrification-denitrification (SND) processes in aerobic reactors enables compliance with TN discharge limits. In the second phase, the configuration is simplified by means of process simulation, where the complex design is streamlined by eliminating internal recycle while achieving nitrogen removal through the SND process. Plant data confirmed that the simplified configuration can achieve nitrogen removal providing the same discharge quality. The simulations resulted that TN concentration achieved at the plant effluent is comparable, while effluent total phosphorus concentration is decreased by approximately 50 % due to increased activity of Phosphorus Accumulating Organisms (PAOs) under reduced sludge retention time (SRT). In the third phase, the application of the SND process in the field using a simplified and new activated sludge configuration yields similar results to the simulation. According to plant records, 28 % energy savings and an equivalent chemical cost reduction of €945,000 per year were achieved with the new process configuration.
AB - In this study, simulation-based analysis is conducted for nitrogen removal mechanism in a biological nutrient removal plant designed in an encrypted manner. In the first phase, the simulation study elucidates how nitrogen removal occurs in a complex design using a series of 4 carousel bioreactors with additional nitrate recycle. It is demonstrated that pre-anoxic volume fed with limited internal recirculation only would not be sufficient to meet the discharge Total Nitrogen (TN) limit of 10 mg N/L. However, the addition of simultaneous nitrification-denitrification (SND) processes in aerobic reactors enables compliance with TN discharge limits. In the second phase, the configuration is simplified by means of process simulation, where the complex design is streamlined by eliminating internal recycle while achieving nitrogen removal through the SND process. Plant data confirmed that the simplified configuration can achieve nitrogen removal providing the same discharge quality. The simulations resulted that TN concentration achieved at the plant effluent is comparable, while effluent total phosphorus concentration is decreased by approximately 50 % due to increased activity of Phosphorus Accumulating Organisms (PAOs) under reduced sludge retention time (SRT). In the third phase, the application of the SND process in the field using a simplified and new activated sludge configuration yields similar results to the simulation. According to plant records, 28 % energy savings and an equivalent chemical cost reduction of €945,000 per year were achieved with the new process configuration.
KW - Denitrification
KW - Denitrification potential
KW - Dissolved oxygen control
KW - Encrypted design
KW - Plant upgrade
KW - Simultaneous nitrification
UR - http://www.scopus.com/inward/record.url?scp=85182383570&partnerID=8YFLogxK
U2 - 10.1016/j.jwpe.2023.104760
DO - 10.1016/j.jwpe.2023.104760
M3 - Article
AN - SCOPUS:85182383570
SN - 2214-7144
VL - 58
JO - Journal of Water Process Engineering
JF - Journal of Water Process Engineering
M1 - 104760
ER -