Anaerobic biodegradation screening tests

Biodegradation aqueous aerobic t,/2 = 24-168 h, based on unacclimated grab sample of aerobic soil (Sims Sommers 1985 quoted, Howard et al. 1991) aqueous anaerobic t,2 = 168-672 h, based on anaerobic acclimated screening test data (Naik et al. 1972 selected, Howard et al. 1991). 

Most of the test methods used to assess the anaerobic biodegradability of organic chemicals have been screening level tests based upon measuring the increase in gas volume or pressure resulting from the conversion of a test material to carbon dioxide (C02) and methane (CH4), such as the ECETOC-28 test [3,4],... 

Biological. Complete microbial degradation to carbon dioxide was reported under anaerobic conditions by mixed or pure cultures. Under enzymatic conditions formaldehyde was the only product reported (Vogel et al., 1987). In a static-culture-flask screening test, methylene chloride (5 and 10 mg/L) was statically incubated in the dark at 25 °C with yeast extract and settled domestic wastewater inoculum. After 7 d, 100% biodegradation with rapid adaptation was observed (Tabak et al., 1981). 

Screening tests for anaerobic biodegradation are of particular value for azo dyes. Since disruption of conjugation of the molecule results from reduction of the azo bond, color change or loss of color is an excellent indicator of the initial steps of degradation of these... 

Ecological and Toxicological Association of the Dyestuffs Manufacturing Industry. Ecological method No. 105. A Screening test for assessing the primary anaerobic biodegradability of water soluble dyestuffs. ETAD, Basel, Switzerland. 

Biodegradation aerobic t,/2(aq.) = 672-4320 h, based on acclimated aerobic soil screening test data (Tabak et al. 1981 quoted, Howard et al. 1991) anaerobic t,/2(aq.) = 1944-4152 h, based on anaerobic sediment grab sample data (Barrio-Lage et al. 1986 quoted, Howard 1989 Olsen Davis 1990 Howard et al. 1991). 

Biodegradation t/2(aerobic) = 168-672 h, based on unacclimated aqueous screening test data t,/2(anaerobic) = 672-2688 h, based on estimated aqueous aerobic biodegradation half-life (Howard etal. 1991) Biotransformation ... 

---