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Biodegradation in water: screening tests

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Reference
Endpoint:
biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
key study
Study period:
From 2000-03-30 to 2000-04-27
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to guideline
Guideline:
OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)
Version / remarks:
1993
Deviations:
no
GLP compliance:
yes
Specific details on test material used for the study:
Batch No.: Partie 1
Purity: 68.3%
Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, domestic, non-adapted
Details on inoculum:
- Source of inoculum/activated sludge: laboratory wastewater plant treating municipal sewage
- Laboratory culture:
- Method of cultivation:
- Storage conditions:
- Storage length:
- Preparation of inoculum for exposure:
- Pretreatment:
- Concentration of sludge:
- Initial cell/biomass concentration: dry substance 30 mg/L
- Water filtered: yes/no
- Type and size of filter used, if any:
Duration of test (contact time):
28 d
Initial conc.:
47.6 mg/L
Based on:
test mat.
Parameter followed for biodegradation estimation:
DOC removal
Details on study design:
Mixtures of the test substance, a defined inorganic medium and a non pre-adapted inoculum are incubated and aerated at room temperature up to 28 days . The biologically produced carbon dioxide is trapped and measured.
Reference substance:
aniline
Preliminary study:
- TOC [mg/g]: 422
- DOC [mg/g]: 429
- TC [mg/g]: 430, referring to the original test substance
- TC [mg/g]: 657, referring to the dry residue
Key result
Parameter:
% degradation (CO2 evolution)
Value:
74
Sampling time:
28 d
Details on results:
- Duration of adaptation phase (days): 13
- Duration of degradation phase (days): 15
- Degradation of the test subst . at the end of the ten-day window (% CO2/ThCO2): 70-80
- Degradation degree of the test subst . at the end of the test (% CO2/ThCO2): 70-80
- Elimination of the test substance after 28 days (%DOC): 90-100
- Degradation degree of the reference substance after 14 days (% CO2/ThCO2): 70-80
- Degradation degree in the inhibition control after 14 days (% CO2/ThCO2): 60-70
Validity criteria fulfilled:
yes
Interpretation of results:
readily biodegradable
Conclusions:
The test substance is readily biodegradable.
Executive summary:

The Biodegradability of test item was determined in the C02-Evolution Test according to OECD Guideline 301 B.

The test concentration was 47.6 mg/L equivalent to 20 mg/L TOC.Activated sludge from laboratory wastewater plant treating municipal sewage was used as inoculum. Concentration of dry substance was 30 mg/L.

The Biodegradation degree (CO2 to ThCO2) after 28 days was 70-80 % and DOC-elimination of the test substance after 28 days was 90-100 %.

Therefore, the test substance is readily biodegradable.

Description of key information

One CO2-Evolution Test (OECD Guideline 301 B) was available, the Biodegradation degree (CO2 to ThCO2) after 28 days was 70-80 % and DOC-elimination of the test substance after 28 days was 90-100 %. The test substance is readily biodegradable.

Key value for chemical safety assessment

Biodegradation in water:
readily biodegradable
Type of water:
freshwater

Additional information

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