Study on Optimal Controlling Strategy of Backwashing Process in Biological Aerated Filter

Abstract:

Basing on comprehensive analysis of the existing backwashing modes of Biological Aerated Filter (BAF), air and water combined backwashing was taken as the most efficient and economic mode for BAF backwashing in this study to ensure operating stability and backwashing effect. Then the relevant parameters, involved in air flushing, air and water combined washing and water rinsing, were optimized reasonably. In this paper, the optimal backwashing control strategy was recommended as follows: air backwashing 3 minutes with air backwashing intensity of 10 L/m²·s,secondly, air and water combined backwashing 3 minutes with both air and water backwashing intensity of 10 L/m²·s,at last,water rinsing for 9 minutes with water rinsing intensity of 10 L/m²·s. To discuss the influence of backwashing process on treatment efficiency of BAF, the changes of headloss and contaminants concentration of BAF before and after backwashing was also investigated in this study. The experimental results revealed that under the optimal backwashing control strategy the water flux could be recovered soon after backwashing. Although the contaminants concentration in initial filtrated water increased slightly, the treatment efficiency of BAF reactors could be back to normal in 2 hours.

• Periodical: Applied Mechanics and Materials (Volume 507)
• Pages: 874-879
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.507.874
• Online since: January 2014
• Authors: Shou Bin Zhang, Li Ping Qiu*, Kang Xie
• Keywords: Backwashing Controlling Strategy, Backwashing Parameters, Biological Aerated Filter (BAF)

References

[1] T. Hidaka, H. Tsuno. Development of a biological filtration model applied for advanced treatment of sewage[J]. Water Res, 2004, 38(2): 335-346.

DOI: 10.1016/j.watres.2003.09.024

[2] Liping Qiu, Jun Ma and Lixin Zhang. Characteristics and utilization of biologically aerated filter backwashed sludge[J]. Desalination, 2007, 208(1-3): 73-80.

DOI: 10.1016/j.desal.2006.04.075

[3] Jinshui Yang, Weijie Liu, Baozhen Li. Application of a novel backwashing process in upflow biological aerated filter [J]. Journal of Environmental Sciences, 2010, 22(3): 362-366 (in Chinese).

DOI: 10.1016/s1001-0742(09)60116-9

[4] Hozalski R M, Bouwer E J. Non-steady state simulation of BOM removal in drinking water biofilters: applications and full-scale validation[J]. Water Research, 2001, 35(1): 211-223.

DOI: 10.1016/s0043-1354(00)00226-8

[5] Qiu L. P., Ma J. Characters of biofilm and its micoorganism population in biological aerobic filter. China Environmental Science, 2005, 25(2): 214-217 (in Chinese).

[6] State Environmental Protection Administration of China. Analysis methods for the Examination of Water and Wastewater(4rd), Beijing: China Environmental Science Press, 2002(in Chinese).

[7] Liping Qiu, Guangwei Wang, Shoubin Zhang et al. Backwashing of Upflow Biological Aerated Filter[J]. Chinese Journal of Environmental Engineering, 2011, 5(7): 1522-1526(in Chinese).