Development of urban wastewater treatment model using nano bubbles with an emphasis on increasing the efficiency of wastewater treatment

Document Type : Research Paper


1 Department of Civil & Environmental Engineering, Kish campus, University of Tehran, Kish, Iran

2 Department of Civil & Environmental Engineering, University of Tehran, Tehran, Iran


Activated sludge process is one of the most widely used methods of urban wastewater treatment. The purpose of this study is to use nanobubbles to supply oxygen to the aeration reactor in the activated sludge process and to evaluate its performance in terms of increasing the efficiency of wastewater treatment, reducing energy consumption, reducing the amount of excess sludge and its impact on environmental factors. The results showed that the use of nano-bubble compared to the use of macro-sized bubbles increased the concentration of dissolved oxygen in the aeration reactor up to 3 mg/liter, 18% reduction in energy consumption, 10% reduction in the initial investment in the construction of the wastewater treatment plant. 15% reduction in operating costs of the sewage treatment plant. Increasing the efficiency of removing organic pollutants and reducing the hydraulic retention time in the aeration system, reducing the size of the treatment plant by 10% due to the increase in the efficiency of removing organic substances, and as a result, reducing the hydraulic time and reducing the same amount of land for the construction of the aeration reactor and facilities for the production and distribution of air in the aeration reactor. The presented model, which is obtained by using nano-bubbles in the aeration process of bioreactors, is very effective as a new and innovative technology in preserving, cleaning, and sustaining the environment. 


Main Subjects

Brenner, A. 1997. Use of computers for process design analysis and control: Sequence Batch peactor, Application. Sci. tech. Vol. 35, No. 1, PP. 95-104.
Bhushan, B., Wang, Y. & Maali, A. 2008. Coalescence and movement of nanobubbles studied with tapping mode AFM and tip-bubble interaction analysis. Journal of physics: condense matter. Vol. 20, 10p.
Attard, P., Moody, M. & Tyrrel, J. 2002. Nanobubbles the picture. Physica A; Vol. 314. Issue 1-4, P. 696, 10p.
Chatlin, M. 2009. Magnetic and electric effects on water. Water structure and science.
Ducker, W. & Zhang, X. 2007. Nanobubbles exist, and are more stable than previously thought. Nanotechnology/nanophysics.
Holmberg, M., Khle, A., Mrch, K. & Boisen, A. 2003. Nanobubble trouble on gold surface. Langmuir. Vol. 19, P. 10510-10513.
Tsuge, Micro and nanobubbles fundamentals and applications, CRC press Taylor & Francis group, 2015.
Irvine, R. L. & Busch, A. W. 1979. Sequence batch reactors and overview. J. WPCF. Vol. 51. No. 2, PP. 235 – 243.
Lindsay, Cotton M. & Feigenbaum, B. (1984) 'Rationing by waiting lists', American Economic Review 74(3): 404-17.
Lagoon System in Marine. 2008. Choosing the right aeration system.
Lou-S., Gao. J., Xiao, X., Lix., Li, G., Zhang Y. , Li M. , Sun, J. , li. , X. & Hu J. 2002. Studies of nanobubbles produced at liquid / solid interfaces. Materials characterization. Vol. 48, P. 211-214.
Metcalf & Eddy, Inc. (2003). Wastewater engineering: treatment and reuse. Boston: McGraw-Hill,
Ahmadi, M., Nabi Bidhendi, Gh., Torabian, A., Mehrdadi, N. 2018. Effects of nanobubble aeration in oxygen transfer efficiency and sludge production in wastewater biological treatment, J Adv. Environ Health Res, 6:225-233
Metcalf-Eddy, Inc. 1991. Wastewater engineering, treatment, disposal and reuse. 3eddition, Mc-Graw Hill, Inc. New York.
Otsuka, I., Yaolta, M., Higano, M. & Nagashima, S. 2003. Spontaneous formation of air nanobubbles on hydrocarbons deposited on the Au (III)/water interface. Surface review and lrtters. Vol. 10, P. 337-343.
Treybal, R.E., Mass Transfer operations, 3rd Edition, McGraw Hill, 1980.
Junkins, R., Deeny, K., Eckhoff, T. 983.The Activated Sludge Process: Fundamentals of Operation, Ann Arbor Science.
Rafael, R. T., & Robio, J. 2007. DAF-dissolved air flotation: Potential applications in the mining and mineral processing industry. Int. J. Miner. Process. 82. 1-13.
Zhang, L. & et all. 2008. Long lifetime of nanobubbles due to high inner desity. Sci china Ser G-Phys Mech Astron. Vol. 51, No. 2, PP. 219 – 224.
Marwa, S. & et all. 2021. A critical review of the recent developments in micro–nano bubbles applications for domestic and industrial wastewater treatment. Alexandria Engineering Journal Volume 61, Issue 8, August 2022, Pages 6591-6612.