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Environmental fate & pathways

Biodegradation in water: screening tests

Administrative data

Endpoint:
biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1992-01-10 to 1992-02-11
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP compliant; Guideline Study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1992
Report Date:
1992

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method C.4-C (Determination of the "Ready" Biodegradability - Carbon Dioxide Evolution Test)
Version / remarks:
reported as 84/449/EEC C.5 Biotic degradation: modified Sturm test
Deviations:
no
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, domestic, non-adapted
Details on inoculum:
Bacteria collected from activated sludge of the sewage treatment plant of CH-4153 Reinach on 13/01/92. The pH after collection was 7.7 .
The preparation was carried out according to the method described in the guideline.
Duration of test (contact time):
28 d
Initial test substance concentrationopen allclose all
Initial conc.:
20.9 mg/L
Based on:
test mat.
Initial conc.:
40.2 mg/L
Based on:
test mat.
Parameter followed for biodegradation estimation
Parameter followed for biodegradation estimation:
CO2 evolution
Details on study design:
- Vessels: 2 Liter flasks (dark brown glass) equipped with gas inlet and magnetic; stirrer;
- Water: The test medium was prepared according to the method described in the guideline
- Temperature: 22 +/- 2°C;
- Duration: 28 days;
- Air: 25 mL/min purified from carbon dioxide;
Reference substance
Reference substance:
aniline

Results and discussion

Test performance:
1200 mL water with the inoculum were aerated for 24 hours in the test vessel. In 300 mL water 15 mL Polyoxyethylen-Sorbitan-Monooleate (TWEEN 80 FLUKA 93781) (solution of 30 mg in 100 mL bidist. water) and 31.4 rsp. 60.3 mg of test substance were added and homogenized. This solution was given to the test vessel which was immediately connected to the CO2 traps.
Reference substance : 20 mg/L
Blank : Water with inoculum containing 3.0 mg/L TWEEN 80
% Degradationopen allclose all
Parameter:
% degradation (CO2 evolution)
Value:
7
Sampling time:
28 d
Remarks on result:
other: 20.9 mg test substance/L
Parameter:
% degradation (CO2 evolution)
Value:
2
Sampling time:
28 d
Remarks on result:
other: 40.2 mg test substance/L

BOD5 / COD results

Results with reference substance:
Biodegradation of the reference substance: 93% in 28 days

Any other information on results incl. tables

The biodegradation was calculated as:

20.9 mg test substance/L = 7% in 28 days.

40.2 mg test substance/L = 2% in 28 days.

Reference substance: 20 mg/L = 93% in 28 days.

Applicant's summary and conclusion