Improving OSA Process Efficiency in Sludge Production Reduction in SBR
Document Type : Full Length Article
Authors
1 1 School of Civil Engineering, College of Engineering, University of Tehran, P.O. Box 11155-4563, Tehran, Iran
2 1 School of Civil Engineering, College of Engineering, University of , Tehran, Iran
3 School of Environmental Engineering, College of Environment, University of , Tehran, Iran
Abstract
OSA (Oxic Settling Anoxic) process is one of the sludge reduction methods. In this method an anaerobic reactor is placed in activated sludge recycling line for sludge reduction purpose. This method is getting popular because of possibility of its application in currently operating waste water treatment plants. In this research, the performance of OSA process in sludge reduction in SBR was improved through thermal and mechanical treatment of recycling activated sludge. An experimental pilot was developed for this purpose. Sludge was warmed up to 50, 70 and 90 ◦C. A mechanical mixer with different voltages was used for mechanical treatment of sludge. By application of OSA process the sludge production was reduced up to 24% and COD removal efficiency was reduced from 90% to 86%. After thermal treatment the sludge production was reduced up to 48%. The sludge reduction would decrease to 34% when mechanical treatment is employed. Application of OSA method does not highly affect the effluent quality based on TSS and COD indicators, but the effluent quality is reduced in case of mechanical and thermal treatment
Keywords
Main Subjects
[1] Laurent, J., Jaziri, K., Guignard, R., Casellas, M., Dagot, C. (2011). "Comprehensive insight of the performances of excess sludge reduction by 90 ◦C thermal treatment coupled with activated sludge at pilot scale: COD and Nremoval, bacterial populations, fate of heavy metals”, Process Biochemistry, 46, 1808–1816.
[2] Perez, E.S., Nieto Diez, I., Polanco, P.F. (2006). "Sludge minimization technologies”, Reviews in Environmental Science and Biotechnology, 5, 375–398.
[3] Riedel, J.R., (2009). “An investigation into the mechanisms of sludge reduction technologies”, M.s Thesis Virginia Polytechnic Institute, USA.
[4] Renze, T.Y., Houtenb, V., Borgerb, A.R., Eikelboomb, D.H., Fana, Y. (2003). "Minimization of excess sludge production for biological wastewater treatment," Water Research Journal, 37, 4453-4467.
[5] Low, E.W., Howard, A. (1998). "Reducing production of excess biomass during wastewater treatment", Water Research Journal, 33(5), 1119-1132.
[6] Novak, J.T., Chon, D.H., Curtis, B., Doyle, M. (2007). "Biological solids reduction using the cannibal process", Water Environment Research, 79(12), 2380-2386.
[7] Ramesh, K., Goel, D., Noguera, R. (2006). "Evaluation of sludge yield and phosphorus removal in a cannibal solids reduction process", Journal of Environmental Engineering, 132(10), 1331-1337.
[8] Mohammadi, A., Mehrdadi, N., Nabi Bidhendi, G., Torabian, A. (2011). "Excess sludge reduction using ultrasonic waves in biological wastewater treatment", Desalination, 275(1-3), 67-73.
[9] Wang, J., Zhao, Q., Jin, W., Lin, J. (2008). “Mechanism on minimization of excess sludge in oxic-settling anaerobic (OSA) process”, Frontiers of Environmental Science & Engineering in China, 2(1), 36–43.
[10]Felodari, P., Andreottola, G., Ziglio, G. (2010). “Sludge reduction technologies in wastewater treatment plant”, First Ed., IWA Pub. Co., New York, USA.
[11]Ye, X., Li, Y. (2010). "Oxic-settling-anoxic (OSA) process combined with 3,3,4,5-tetrachlorosalicylanilide (TCS) to reduce excess sludge production in the activated sludge system", Biochemical Engineering Journal, 49, 229–234.
[12]Ye, F.X., Fen Zhu, R., Li, Y. (2010). "Effect of sludge retention time in sludge holding tank on excess sludge production in the oxic-settling-anoxic (OSA) activated sludge process", Biochemical Engineering Journal, 49, 229–234.
[13]Chon, D.H., Rome, M.N., Kim, Y.M., Park, K.Y., Park, C. (2011). “Investigation of the sludge reduction mechanism in the anaerobic side-stream reactor process using several control biological wastewater treatment processes,” Water Research Journal, 4(5), 6021-6029.
[14]Sun, L., Randall, W.C., Novak, J.T. (2010). "The influence of sludge interchange times on oxic settling anoxic process", Water Environment Research, 82, 519–523.
[15]Strünkmann, G.W., Muller, J.A., Albert, F., Schwedes, J. (2006). "Reduction of excess sludge production using mechanical disintegration devices", Water Science and Technology, 54(5), 69-76.
[16]APHA, (2005). “Standard methods for the examination of water and wastewater”, 18th Ed., American Public Health Association, Washington, DC, USA.
)