1- Gokmen, E., Piskin, F., and Erdirencelebi, D. (2009). “Anaerobic treatment of strong character dairy wastewaters in sequential UASBRs: Adaptation period COD removal and pH/HCO3ˉ/VFA Balance.” Progress in, International Symposium on Environmental Sience and Technology, Shanghai, vol.2, part B,
10-13
4- Wang, L. K., Yung, T., and Hung, H. H. (2006). Waste treatment in the food processing industry, CRC Press, Taylor and Francis Group, UAS.
5- Gonze, E., Pillot, S., Valette, E., Gonthier, Y., and Bernis, A. (2003). “Ultrasonic treatment of an aerobic activated sludge in a batch reactor.” Chemical Engineering and Processing, 42, 965-975.
6- Laborde, J.L., Bouyer, C., Caltagirone, J.P., and Ge´rard, A. (1998a). “Acoustic bubble cavitation at low frequencies.” Ultrasonics, 36, 589-594.
7- Petrier, B., and Francony, A. (1997). “Incidence of wave-frequency on the reaction rates during ultrasonic wastewater treatment.” Water Science Technology, 35 (4), 175-180.
8- Young, F.R. (1989). Cavitation, McGraw-Hill Book Co.,Maidenhead,UK.
9- Reports on Sanitary Engineering. (2000). Ultrasonic waste activated sludge disintegration for improving anaerobic stabilization, GFEU-Verlag Pub., Tu Hamburg, Germany.
10- Chio, H.B., Hwang, K.Y., and Shin, E.B. (1997). “Effect on anaerobic digestion of sewage sludge pretreatment.” J. Water Sci. Technol, 35 (10), 207-211.
11- Muller, J. (2001). “Disintegration as a key-step in sewage sludge treatment.” Water Sci. Technol, 41 (8),
123-130.
12- Tiehm, A., Nickel, K., Zellhorn, M., and Neis, U. (2001). “Ultrasonic waste activated sludge disintegration for improving anaerobic stabilization.” J. Water Res., 35 (8), 2003-2009.
13- Tiehm, A., Nickel, K., and Neis, U. (1997). “The use of ultrasound to accelerate the anaerobic digestion of sewage sludge.” Water Sci. Technol., 36(11), 121-128.
14- Chu, C.P., Lee, D.J., You, C.S., and Tay, J.H. (2002). “Weak ultrasonic pre-treatment on anaerobic digestion of flocculated activated biosolids.” Water Res., 36, 2681-2688.
15- 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.
16- S. Deleris, J.M. (2000). “Rouston, Effect of ozonation on activated sludge solubilization and mineralization.” Ozone Sci. Eng., 22, 473-486.
17- 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, 656-666.
18- Lendormi, T., Prevot, C., Doppenberg, F., Serandio, M., and De Bellefontaine, H. (2001). “Wet oxidation of domestic sludge and process integration: The mineralis process.” Water Sci. Technol., 44 (10), 163-169.
19- Chiu, Y.C., Chang, C.N., Lin, J.G., and Huang, S.J. (1997). “Alkaline and ultrasonic pre-treatment of sludge before anaerobic digestion.” Water Sci. Technol., 36 (11),155-162.
20- Tanaka, S., and Kamiyama, K. (2002). “Thermochemical pretreatment in the anaerobic digestion of waste activated sludge.” Water Sci. Technol., 46 (10), 173-179.
21- Camacho, P., Deleris, S., Geaugey, V., Ginestet, P., and Paul, E. (2002). “A comparative study between mechanical,thermal and oxidative disintegration techniques of waste activated sludge.” Water Sci. Technol., 46 (10), 79-87.
22- Zahedi, A. (2008). “Application of ultrasonic wave irradiation for aerobic digestion waste-activated sludge.” M.Sc. Thesis of EnvironmentalEng.,TehranUniversity,Tehran,Iran. (In Persian)
23-Williams, A.R. (1983). Ultrasond: Biological effect and potential hazards, Academic Press (CORP), UAS.
24- Piyasena, P., Mohareb, E., and McKellar, R.C. (2003). “Inactivation of microbes using ultrasound: A review.” Int. J. of Food Microbial, 87 (3), 207-216.