Intermittent Ozonation to Reduce Excess Biological Sludge in SBR

Document Type : Research Paper

Authors

1 Assist. Prof., Dept. of Environmental Health Engineering, Jondishapoor University of Ahwaz

2 Assist. Prof., Dept. of Civil Engineering, Azad Islamic University, Ahar Branch

3 Prof., Dept. of Environmental Engineering,Tehran University

Abstract

A combination of ozonation and an aerobic biological process such as the activated sludge has been recently developed as an alternative solution for sludge reduction with the objective of minimizing the excess biological sludge production. In this study, two SBR reactors each with a capacity of 20 liters and controlled by an on-line system are used. Once the steady state conditions were set in the reactors, sampling and testing of such parameters as COD, MLSS, MLVSS, DO, SOUR, SVI, residual ozone, and Y coefficient were performed over the 8 months of research. Results showed that during the solid retention time of 10 days, the kinetic coefficients of Y and Kd were 0.58 mg biomass/mg COD and 0.058 1/day, respectively. In the next stage of the study, different concentrations of ozone in the reactor were intermittently used to reduce the excess biological sludge production. The results showed that 22 mg of ozone per 1 gram of MLSS in the reactor was able to reduce the yield coefficient Y from 0.58 to 0.23 mg Biomass/mg COD. In other words, the excess biological sludge reduced by 60% but the soluble COD increased slightly in the effluent and the removal percentage decreased from 92 in the blank reactor to 76 in the test reactor. While the amount of SVI and SOUR for this level of ozone concentration reached 6 mgO2/h.gVSS and 27 ml/g, respectively. No excess sludge was observed in the reactor for an ozone concentration of 27 mg per 1 gram of MLSS.

Keywords

References

1- Tchobanglous, G., and Burton, F. (2003). Wastewater engineering: Treatment ,disposal and reuse, 4th Ed., McGraw Hill, Metcalf and Eddy Inc.,New York.
2- Wisaam, S., Rekabi, A., and Qiang, W. (2007). “Review on sequencing batch reactors.” Pakistan J. of Nutrition, 6 (1), 11-19.
3- Low, E. W., and Chase, H.A.(1999). “Reducing production of excess biomass during wastewater treatment.” Wat. Res., 33(5), 1119-1132.
4-Bitton, G. (2002). Wastewater microbiology,Willey-Liss,New York.
5- تکدستان، ا.، ترابیان، ع.، عظیمی، ع . (1385). ”روشهای کاهش تولید لجن بیولوژیکی در فرایندهای هوازی تصفیه فاضلاب. “ اولین همایش ملی بهرهبرداری در بخش آب و فاضلاب، شرکت مهندسی آب و فاضلاب کشور، تهران، 234-240.
6- تکدستان، ا.، و ترابیان، ع. (1386). ”بررسی کاهش تولید لجن مازاد بیولوژیکی در راکتو ناپیوسته متوالی (SBR) توسط اکسیداسیون بخشی از لجن بوسیله کلر.“ دهمین همایش کشوری بهداشت محیط، دانشگاه همدان، 24-30.
7-USEPA. (1999). Wastewater technology fact sheet sequencing batch reactors, United States Environmental Protection Agency, 832-F-99-073,USA.
8- تکدستان، ا.، و ترابیان، ع. (1387). ”بررسی کاربرد متناوب کلر در کاهش تولید لجن مازاد بیولوژیکی در راکتور ناپیوسته متوالی
(SBR). “دومین همایش کشوری مهندسی محیط زیست دانشگاه تهران، تهران، 374-380.
9- Canales, A., Pareilleux, A., Rols, J. L., Goma, C., and  Huyard, A. (1994). “Decreased sludge production strategy for domestic wastewater treatment.” Wat. Sci. Thecnol., 30(8), 96-106.
10-APHA., AWWA., WPCF. (1995). Standard method for the examination of water & wastewater, 22th Ed. A.P.H.A.N.W,WashingtonD.C.
11-Liu, Y., and Tay, J. H. (2001). “Strategy for minimization of excess sludge production from the activated sludge process.” Biotech. Adv., 19(2), 97-107.
12- Liu, Y.(2003). “Chemically reduced excess sludge production in the activated sludge process.” Chemosphere, 50, 1-7.
13- Yasui, H., Nakamura, K., Sakuma, S., Iwasaki, M., and Sakai, Y. (1996). “A full-sale operation of a novel activated sludge process without excess sludge production.” Water Sci. Technol., 34 (3-4), 395-404.
14- Sakai, Y., Fukase, T., Yasui, H., and Shibata, M. (1997). “An activated sludge process without excess sludge production.” Water Sci. Technol., 36(11), 163-170.
15- Kamiya, T., and Hirotsuji, J. (1998). “New combined system of biological process and intermittent ozonation  for advanced wastewater treatment.” Water Sci. Technol., .38 (8-9), 145-153.
16- Yasui, H., and Shibata, M. ( 1994). “An innovative approach to reduce excess sludge production in the activated sludge process.” Water Sci.Technol., 30 (23), 11-20.
17-Liu, Y. (2000). “Effect of chemical uncoupler on the observed growth yield in batch culture of activated sludge.” Water Res., 3(4), 2025-2030.
18-Liu, Y., and Tay, J. H. (2000). “A kinetic model for energy spilling-associated product formation in substrate-sufficient continuous culture.” J. Appl. Microbiol., (88), 663-668.
19-Low, W. W., Chase, H. A., Milner, M.G., and Curtis, T.P. (2000). “Uncoupling of metabolism to reduce biomass production in the activated sludge process.” Water Res., 34, 3204-3212.
20- Sabya, S., Djafera, M., and Hao Chenb, G. (2003). “Effect of low ORP in anoxic sludge zone on excess sludge production In OSA activated sludge process.” Water Res., 37(1), 11-20.
21- Wunderlich, R, Barry, J., and Greenwood, D. (1985) “Start up of a High-purity oxygen activated sludge system at the los angelescountry sanitation districts.” J. Wat. Poll. Control Fed., 57, 1012-1018.
22-Saby, S., Djafer, M., and Chen, G. H. ( 2002) “Feasibility of using a chlorination step to reduce excess sludge in activated sludge process.” Water Res., 36 (3), 656-666.
23- Chen, G., and Saby, S. (2003). “New approaches to minimize excess sludge in activated sludge system.” Water Sci. Technol., 44 (10), 203-208.
24- Rocher, M., Roux, G., Goma, G., Begue, AP., Louvel, L., and Rols, J.L. (2001). “Excess sludge reduction in activated sludge processesby integrating biomass alkaline heat treatment.” Water Sci. Technol., 44(2–3), 437-444.
25-Lee, U., Topfl, S., and Heinz, V. “Application of  pulsed electric fields for the reduction of excess sludge.” J. of Biotechnology and Process Engineering, 12, 8-13.
26-Hoon Yoon, S., SooKim, H., and Lee, S. (2004). “Incorporation of ultrasonic cell disintegration into a membrane bioreactor for zero sludge production.” Process Biochemistry, 39, 1923-1929. 
27-Huang X.,  Liang, P., and Qian, Y. (2007). “Excess sludge reduction induced by Tubifex tubifex in a recycle sludge reactor.” Journal of Biotechnology, 127, 443-453.
28- Liang, P., Huang, X., and Qain, Y. (2006). “Excess sludge reduction in activated sludge process through predation of Aeolosoma hemperichi.” Chemistry Engineering Journal, 28, 117-122.
29- Liang, C., Huang, X., Qian, Y., Wei Y., and Ding, g. (2006). “Determination and comparison of sludge reduction rates caused by microfaunas, predation.” Bioresource Technology, 97, 854-861.
30- Abbassi, B., Dullstein, S., and Rabiger, N. (2000). “Minimization of excess sludge production by increase of oxygen concentration in activated sludge flocs: Experimental and theoretical apperoch.” Water Res., 34 (1), 139-146.
Journal of Water and Wastewater; Ab va Fazilab ( in persian )
Volume 20, Issue 3 - Serial Number 3
Serial number:71
September and October 2009
Pages 41-49

Files

Share

How to cite

Statistics