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© IWA Publishing 2015 Water Science & Technology
|
71.7
|
2015
Modeling of organic substrate transformation in the high-rate activated sludge process Thomas Nogaj, Andrew Randall, Jose Jimenez, Imre Takacs, Charles Bott, Mark Miller, Sudhir Murthy and Bernhard Wett
ABSTRACT This study describes the development of a modified activated sludge model No.1 framework to describe the organic substrate transformation in the high-rate activated sludge (HRAS) process. New process mechanisms for dual soluble substrate utilization, production of extracellular polymeric substances (EPS), absorption of soluble substrate (storage), and adsorption of colloidal substrate were included in the modified model. Data from two HRAS pilot plants were investigated to calibrate and to validate the proposed model for HRAS systems. A subdivision of readily biodegradable soluble substrate into a slow and fast fraction were included to allow accurate description of effluent soluble chemical oxygen demand (COD) in HRAS versus longer solids retention time (SRT) systems. The modified model incorporates production of EPS and storage polymers as part of the aerobic growth transformation process on the soluble substrate and transformation processes for flocculation of colloidal COD to particulate COD. The adsorbed organics are then converted through hydrolysis to the slowly biodegradable soluble fraction. Two soluble substrate models were evaluated during this study, i.e., the dual substrate and the diauxic models. Both models used two state variables for biodegradable soluble substrate (SBf and SBs) and a single biomass population. The A-stage pilot typically removed 63% of the soluble substrate (SB) at an SRT 3 days) where the biodegradable soluble organic substrate (SB) can be modeled as a single substrate with a single kinetic expression. However, full-scale and pilot-scale results from HRAS (Jimenez ; Haider et al. ; Miller et al. ) show that very low SRT (i.e. 1 day) effluent soluble COD for the HRSD A-stage. The dual substrate model was more accurate than the diauxic model with respect to effluent soluble COD during the validation phase using HRSD A-stage data.
ACKNOWLEDGEMENT This paper was presented at WWTmod2014 and the fruitful discussions are kindly acknowledged.
REFERENCES Beun, J. J., Paletta, F., Van Loosdrecht, M. C. M. & Heijnen, J. J. Stoichiometry and kinetics of poly-hydroxybutyrate metabolism in aerobic, slow growing, activated sludge cultures. Biotechnology and Bioengineering 67 (4), 379– 389. doi: 10.1002/(SICI)1097-0290(20000220)67:4 < 379:: AID-BIT1 > 3.0.CO;2-2. Böhnke, B. & Diering, B. United States Patent No. 4,568,462. U. S. P. a. T. Office. Carucci, A., Dionisi, D., Majone, M., Rolle, E. & Smurra, P. Aerobic storage by activated sludge on real wastewater. Water Research 35 (16), 3833–3844. Dold, P. L., Ekama, G. A. & Marais Van, G. R. A general model for the activated sludge process. Progress in Water Technology 12 (6), 47–77. Ekama, G. A., Dold, P. L. & Marais Van, G. R. Procedure for determining influent COD fractions and the maximum specific growth rate of heterotrophs in activated sludge systems. Water Science and Technology 18 (6), 91–114. Frolund, B., Griebe, T. & Nielsen, P. H. Enzymatic activity in the activated-sludge floc matrix. Applied Microbiology and Biotechnology 43 (4), 755–761. Haider, S., Svardal, K., Vanrolleghem, P. A. & Kroiss, H. The effect of low sludge age on wastewater fractionation (SS, SI). Water Science and Technology 47, 203–209.
Water Science & Technology
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71.7
|
2015
Henze, M., Gujer, W., Mino, T. & Van Loosdrecht, M. Activated Sludge Models ASM1, ASM2, ASM2d and ASM3. IWA Publishing, London, 121. Jimenez, J. A. Kinetics of COD removal in the activated sludge process including bioflocculation, The Department of Civil and Environmental Engineering (PhD thesis), University of New Orleans, umi:3084238. Jimenez, J. A., La Motta, E. J. & Parker, D. S. Kinetics of removal of particulate chemical oxygen demand in the activated-sludge process. Water Environment Research 77 (5), 437–446. Laspidou, C. S. & Rittmann, B. E. a Non-steady state modeling of extracellular polymeric substances, soluble microbial products, and active and inert biomass. Water Research 36 (8), 1983–1992. Laspidou, C. S. & Rittmann, B. E. b A unified theory for extracellular polymeric substances, soluble microbial products, and active and inert biomass. Water Research 36 (11), 2711–2720. Li, X. Y. & Yang, S. F. Influence of loosely bound extracellular polymeric substances (EPS) on the flocculation, sedimentation and dewaterability of activated sludge. Water Research 41 (5), 1022–1030. Mamais, D., Jenkins, D. & Pitt, P. A rapid physical-chemical method for the determination of readily biodegradable soluble COD in municipal wastewater. Water Research 27 (1), 195–197. Miller, M. W., Regmi, P., Bunce, R., Hingley, D. M., Kinnear, D., Wett, B., Murthy, S. & Bott, C. B. A/B Process Pilot Optimized for Nitrite Shunt: High Rate Carbon Removal Followed by BNR with Ammonia-Based Cyclic Aeration Control. Paper presented at the WEFTEC 2012, New Orleans, Louisiana, Water Environment Federation, Alexandria Virginia. Miller, M. W., Jimenez, J., Murthy, S., Kinnear, D., Wett, B. & Bott, C. B. Mechanisms of COD Removal in the Adsorption Stage of the A/B Process. Paper presented at the WEFTEC 2013, Chicago, Illinois, Water Environment Federation, Alexandria Virginia. Pala-Ozkok, I., Rehman, A., Kor-Bicakci, G., Ural, A., Schilhabel, M. B., Ubay-Cokgor, E., Jonas, D. & Orhon, D. Effect of sludge age on population dynamics and acetate utilization kinetics under aerobic conditions. Bioresource Technology 143, 68–75. Schulze-Rettmer, R. & Zuckut, S. W. Treatment of textile dyeing wastewater by adsorption/bio-oxidation process. Textile Chemist and Colorist 30 (5), 19–23. Sin, G., Guisasola, A., De Pauw, D. J. W., Baeza, J. A., Carrera, J. & Vanrolleghem, P. A. A new approach for modelling simultaneous storage and growth processes for activated sludge systems under aerobic conditions. Biotechnology and Bioengineering 92 (5), 600–613. Third, K. A., Newland, M. & Cord-Ruwisch, R. The effect of dissolved oxygen on PHB accumulation in activated sludge cultures. Biotechnology and Bioengineering 82 (2), 238–250.
First received 11 July 2014; accepted in revised form 22 January 2015. Available online 6 February 2015
Copyright of Water Science & Technology is the property of IWA Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
© IWA Publishing 2015 Water Science & Technology
|
71.7
|
2015
Modeling of organic substrate transformation in the high-rate activated sludge process Thomas Nogaj, Andrew Randall, Jose Jimenez, Imre Takacs, Charles Bott, Mark Miller, Sudhir Murthy and Bernhard Wett
ABSTRACT This study describes the development of a modified activated sludge model No.1 framework to describe the organic substrate transformation in the high-rate activated sludge (HRAS) process. New process mechanisms for dual soluble substrate utilization, production of extracellular polymeric substances (EPS), absorption of soluble substrate (storage), and adsorption of colloidal substrate were included in the modified model. Data from two HRAS pilot plants were investigated to calibrate and to validate the proposed model for HRAS systems. A subdivision of readily biodegradable soluble substrate into a slow and fast fraction were included to allow accurate description of effluent soluble chemical oxygen demand (COD) in HRAS versus longer solids retention time (SRT) systems. The modified model incorporates production of EPS and storage polymers as part of the aerobic growth transformation process on the soluble substrate and transformation processes for flocculation of colloidal COD to particulate COD. The adsorbed organics are then converted through hydrolysis to the slowly biodegradable soluble fraction. Two soluble substrate models were evaluated during this study, i.e., the dual substrate and the diauxic models. Both models used two state variables for biodegradable soluble substrate (SBf and SBs) and a single biomass population. The A-stage pilot typically removed 63% of the soluble substrate (SB) at an SRT 3 days) where the biodegradable soluble organic substrate (SB) can be modeled as a single substrate with a single kinetic expression. However, full-scale and pilot-scale results from HRAS (Jimenez ; Haider et al. ; Miller et al. ) show that very low SRT (i.e. 1 day) effluent soluble COD for the HRSD A-stage. The dual substrate model was more accurate than the diauxic model with respect to effluent soluble COD during the validation phase using HRSD A-stage data.
ACKNOWLEDGEMENT This paper was presented at WWTmod2014 and the fruitful discussions are kindly acknowledged.
REFERENCES Beun, J. J., Paletta, F., Van Loosdrecht, M. C. M. & Heijnen, J. J. Stoichiometry and kinetics of poly-hydroxybutyrate metabolism in aerobic, slow growing, activated sludge cultures. Biotechnology and Bioengineering 67 (4), 379– 389. doi: 10.1002/(SICI)1097-0290(20000220)67:4 < 379:: AID-BIT1 > 3.0.CO;2-2. Böhnke, B. & Diering, B. United States Patent No. 4,568,462. U. S. P. a. T. Office. Carucci, A., Dionisi, D., Majone, M., Rolle, E. & Smurra, P. Aerobic storage by activated sludge on real wastewater. Water Research 35 (16), 3833–3844. Dold, P. L., Ekama, G. A. & Marais Van, G. R. A general model for the activated sludge process. Progress in Water Technology 12 (6), 47–77. Ekama, G. A., Dold, P. L. & Marais Van, G. R. Procedure for determining influent COD fractions and the maximum specific growth rate of heterotrophs in activated sludge systems. Water Science and Technology 18 (6), 91–114. Frolund, B., Griebe, T. & Nielsen, P. H. Enzymatic activity in the activated-sludge floc matrix. Applied Microbiology and Biotechnology 43 (4), 755–761. Haider, S., Svardal, K., Vanrolleghem, P. A. & Kroiss, H. The effect of low sludge age on wastewater fractionation (SS, SI). Water Science and Technology 47, 203–209.
Water Science & Technology
|
71.7
|
2015
Henze, M., Gujer, W., Mino, T. & Van Loosdrecht, M. Activated Sludge Models ASM1, ASM2, ASM2d and ASM3. IWA Publishing, London, 121. Jimenez, J. A. Kinetics of COD removal in the activated sludge process including bioflocculation, The Department of Civil and Environmental Engineering (PhD thesis), University of New Orleans, umi:3084238. Jimenez, J. A., La Motta, E. J. & Parker, D. S. Kinetics of removal of particulate chemical oxygen demand in the activated-sludge process. Water Environment Research 77 (5), 437–446. Laspidou, C. S. & Rittmann, B. E. a Non-steady state modeling of extracellular polymeric substances, soluble microbial products, and active and inert biomass. Water Research 36 (8), 1983–1992. Laspidou, C. S. & Rittmann, B. E. b A unified theory for extracellular polymeric substances, soluble microbial products, and active and inert biomass. Water Research 36 (11), 2711–2720. Li, X. Y. & Yang, S. F. Influence of loosely bound extracellular polymeric substances (EPS) on the flocculation, sedimentation and dewaterability of activated sludge. Water Research 41 (5), 1022–1030. Mamais, D., Jenkins, D. & Pitt, P. A rapid physical-chemical method for the determination of readily biodegradable soluble COD in municipal wastewater. Water Research 27 (1), 195–197. Miller, M. W., Regmi, P., Bunce, R., Hingley, D. M., Kinnear, D., Wett, B., Murthy, S. & Bott, C. B. A/B Process Pilot Optimized for Nitrite Shunt: High Rate Carbon Removal Followed by BNR with Ammonia-Based Cyclic Aeration Control. Paper presented at the WEFTEC 2012, New Orleans, Louisiana, Water Environment Federation, Alexandria Virginia. Miller, M. W., Jimenez, J., Murthy, S., Kinnear, D., Wett, B. & Bott, C. B. Mechanisms of COD Removal in the Adsorption Stage of the A/B Process. Paper presented at the WEFTEC 2013, Chicago, Illinois, Water Environment Federation, Alexandria Virginia. Pala-Ozkok, I., Rehman, A., Kor-Bicakci, G., Ural, A., Schilhabel, M. B., Ubay-Cokgor, E., Jonas, D. & Orhon, D. Effect of sludge age on population dynamics and acetate utilization kinetics under aerobic conditions. Bioresource Technology 143, 68–75. Schulze-Rettmer, R. & Zuckut, S. W. Treatment of textile dyeing wastewater by adsorption/bio-oxidation process. Textile Chemist and Colorist 30 (5), 19–23. Sin, G., Guisasola, A., De Pauw, D. J. W., Baeza, J. A., Carrera, J. & Vanrolleghem, P. A. A new approach for modelling simultaneous storage and growth processes for activated sludge systems under aerobic conditions. Biotechnology and Bioengineering 92 (5), 600–613. Third, K. A., Newland, M. & Cord-Ruwisch, R. The effect of dissolved oxygen on PHB accumulation in activated sludge cultures. Biotechnology and Bioengineering 82 (2), 238–250.
First received 11 July 2014; accepted in revised form 22 January 2015. Available online 6 February 2015
Copyright of Water Science & Technology is the property of IWA Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
