... (Goto et al., 1997), ozonation (Yasui et al., 1997), hot alkali treatment (Suzuki and Inagaki, 1994),- 80 -biodegradable method by thermophilic bacteria (Hasegawa et al.,1997; Imaoka et al.,1998; ... this readily degradable BOD5 as substrate by active (survival) biomass. After 24 hours, BOD5concentrations in both operating conditions decreased to 1200 mg/L. It was considered that a balance ... Tokiwadai, Ube, Yamaguchi 755-8611, JAPAN** Ube National College of Technology, Tokiwadai, Ube, Yamaguchi 755-8555, JAPANABSTRACTThis study describes the solubilization of excess sludge by high...