ELSEVIER The Science of the TotalEnvironment 170 (1995) 31-41 Testing and classification methods for the biodegradabilities of organic compounds under anaerobic conditions Takashi Kameya* a, Takeshi Murayamaa, Masaru Kitanob, Kohei Uranoa aYokohama National University, 156 Tokiwadai, Hodogaya-ku, Yokohama-city, 240 Japan bShukutoku Junior College, 5-3-7Maeno-machi, Ztabashi-ku, Tokyo, 74 Japan Received 6 June 1994; accepted 21 October 1994 Abstract Biodegradability is one of the most important characteristics of an organic compound for predicting its fate and life in the environment and its applicationin biologicalwastewater treatment. But there is no generaltestingmethod for biodegradability under anaerobicconditions. The biodegradabilities of thirteen principal organiccompounds was investigated in a batch test usingvials under various conditions,suchas the concentration of an organiccompound, the cultivation method and the concentration of anaerobic bacteria for seeding. Two test methods in the standard concentration and the low concentration were developed. A new method to classifythe biodegradabilities of organic compounds into thirteen ranks was proposedby consideringinhibition, complete biodegradation and first step biodegradation. Keywords: Biodegradability; Organic compund; Anaerobic conditions 1. Introduction Synthetic organic compounds cause various en- vironmental problems. Biodegradability is one of the most important characteristics of an organic compound for predicting its fate and life in the environment and its application in biological wastewater treatment: Various testing methods of * Corresponding author. the biodegradabilities of organic compounds un- der aerobic conditions have been reported and several testing methods are set as standards or guidelines (MIT& 1978; OECD, 1981; Japan As- soc. Standard, 1981; Urano and Kato, 1983; Urano and Kato, 1984; Urano and Kato, 1986). However, only a few testing methods under anaerobic con- ditions have been reported (Owen et al., 1979; Shelton and Tiedje, 1985; Battersby and Wilson, 1988; Ito et al., 19861, but there is no general testing method for biodegradabilities under 004%9697/9.5/$09.50 Q 1995 Elsevier Science BV. All rights reserved. SSDZ 0048-9697(95)04529-V