Özlem KARAHAN, Ubay Emine ÇOKGÖR, Derin ORHON, Dizdaroğlu Gülseda RİŞVANOĞLU, Marc C. M. Van LOOSDRECHT

Deri endüstrisi atıksuları için substrat depolama kavramı ve modelleme uygulamaları

Son yıllarda aktif çamur arıtma sistemlerinin tasarımında IWA Çalışma Grubu tarafından önerilen en son model olan ASM3 ile substratin depolama polimerlerine dönüştükten sonra heterotrofik biyokütle tarafından tüketildiği varsayımı dikkate alınmaktadır. Ancak bu yaklaşım uygulama kolaylıkları getirmekle birlikte gerçeği yansıtamamakta ve kolay ayrışan substralın $(S_s)$ tanımı uygulamalarda zorluk yaratmaktadır. Bu çalışmada, daha gerçekçi bir yaklaşım olan, substratın kısmen çoğalma kısmen de depolama ürünleri oluşumu ile tüketildiği görüşü deri atıksuyu için uygulanmıştır. Dinamik koşullar altında, farklı modeller olan ASMI, ASM3 ve ASM3 'ün simültane çoğalma ve depolamayı içeren versiyonları hazırlanarak elde edilen simülasyon sonuçları birbirleri ve literatür verileri ile karşılaştırılmıştır.

The substrate storage concept and the modelling applications for tannery wasteweater

Consumption of substrate firstly in the form of stored polymers and subsequent use of the stored polymers by heterotrophic biomass recently introduced in the activated sludge system design by IWA Task Group with ASM3. Although this approach brings ease of application in calculations, it dose not reflect the reality and the definition of readily biodegradable substrate $(S_s)$ causes problems in applications. A more realistic approach, that is the simultaneous growth and storage concept on external substrate has been presented and applied for tannery wastewater. Different models, namely, ASMI, ASM3 and modified versions of ASM3 involving simultaneous growth and storage have been investigated under dynamic conditions. The simulation results were compared with each other and literature data. Model simulation results for ASMI were quite consistent with literature but the results have shown that ASM3 modeling results gave better descriptions of the OUR response compared to ASMl. The comparison of the simulation results lead to the conclusion that the possibility of describing the real case increases, as the model gets more detailed. Observations suggest that the relative weight of biochemical reactions such as growth and storage shifts as the feeding pattern fluctuates between feast and famine conditions and models with a single mechanism like ASMI, although convenient from a practical viewpoint may become insufficient for a consistent explanation when the feeding rale (F/M ratio) changes.

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1-Beun, J. J., Paletta, F., van Loosdrecht, M. C. M. ve Heijnen, J. J., (2000). Stoichiometry and kinetics of poly-p-hydroxybutyrate metabolism in aerobic, slow growing, activated sludge cultures, Biotechnology and Bioengineering, 67, 4, 379-389.
2-Henze, M., Grady, C. P. L. Jr., Gujer, W., Marais, G. v. R. ve Matsuo, T. (1987). Activated Sludge Model No.l. IAWPRC Scientific and Technical Report No. 1, IAWPRC, London.
3-Henze, M., Gujer, W., Mino, T., Matsuo, T., Wentzel, M. C. ve Marais, G. v. R. (1995). Activated Sludge Model No.2. IAWPRC Scientific and Technical Report No.2, IAWQ, London.
3-Gujer, W., Henze, M., Mino, T. ve van Loosdrecht, M. (2000). Activated Sludge Model No.3. In: Activated Sludge Models ASM1, ASM2, ASM2D and ASM3, Henze, M., Gujer, W., Mino, T., van Loosdrecht, M (eds.) IWA Scientific and Technical Report No 9 IWA London. ISBN: 1 900222 24 8.
4-Karahan-Gül, Ö., Artan, N., Orhon, D., Henze, M. ve van ' Loosdrecht, M. C. M., (2001). Respirometric assessment of storage yield for different substrates. Proceedings of 3rd IWA International Specialized Conference on Microorganisms in Activated Sludge and biofilm Processes, 13-15 June 2001, Rome, Italy, 256-264.
5-Karahan-Gül, Ö.; van Loosdreeht, M. C. M. ve Orhon, D., (2002). Modification of activated sludge model No.3 considering direct growth on primary substrate.
6-Krishna, C. ve van Loosdrecht, M. C. M., (1999b). Substrate flux into storage and growth in relation to activated sludge modeling, Water Research; 33,14,3149-3161
7-Majone, M., Dircks, K. ve Beun, J., J., (1999). Aerobic storage under dynamic conditions in activated sludge processes. The state of art, Water Science and Technology 39, 1, 61-73.
8-Orhon, D., Ateş Genceli, E. ve Ubay Çokgör, E., (1999). Characterization and modelling of activated sludge for tannery wastewater, Water Environment Research, 71, 1, 50-63 9-Reichert, P., Ruchti, J. ve Simon, W., (1998). Aquasim 2.0 Swiss Federal Institute for Environmental Science and Technology (EAWAG), CH-8600 Duebendorf, Switzerland.
10-Roels, J. A., (1983). Energetics and kinetics in biotechnology. Elsevier Biormedical Press, Amsterdam. 330.
11-van Aalst-van Leeuwen, M. A., Pot, M. A.; van Loosdrecht, M. C. M. ve Heijnen, J. J., (1997). Kinetic modeling of poly (B-hydroxybutyrate) production and consumption by P. P. under dynamic substrate supply, Biotechnology and Bioengineering, 55, 5,773-782.
12-van Loosdrecht, M. C. M., ve Heijnen, J. J., (2002). Modeling of activated sludge processes with structured biomass.
13-ISO (1986). Water Quality - Determination of the chemical oxygen demand. Ref.No. ISO 6060-1986.