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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
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The study was performed according to the recommended guidelines and GLP, and without deviations.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2008
Report date:
2008

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
EU Method C.4-C (Determination of the "Ready" Biodegradability - Carbon Dioxide Evolution Test)
Qualifier:
according to guideline
Guideline:
OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)
Qualifier:
according to guideline
Guideline:
ISO DIS 9439 (Ultimate Aerobic Biodegradability - Method by Analysis of Released Carbon Dioxide)
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
other: activated sludge freshly obtained from a municipal sewage treatment plant
Details on inoculum:
Source: the source of test organisms was activated sludge freshly obtained from a municipal sewage treatment plant: 'Waterschap de Maaskant', 's-Hertogenbosch, The Netherlands, receiving predominantly domestic sewage.

Treatment: The freshly obtained sludge was kept under continuous aeration until further treatment. The concentration of suspended solids was 3.3 g/l in the concentrated sludge (information obtained from the municipal sewage treatment plant). Before use, the sludge was allowed to settle (43 minutes) and the liquid was decanted for use as inoculum at the amount of 10 ml/l of mineral medium.
Duration of test (contact time):
28 d
Initial test substance concentrationopen allclose all
Initial conc.:
13 mg/L
Based on:
test mat.
Initial conc.:
10 mg/L
Based on:
other: TOD
Parameter followed for biodegradation estimation
Parameter followed for biodegradation estimation:
CO2 evolution
Reference substance
Reference substance:
acetic acid, sodium salt

Results and discussion

% Degradation
Parameter:
% degradation (CO2 evolution)
Value:
>= 3 - <= 10
Sampling time:
29 d
Details on results:
Points of degradation plot (test substance):
3 % degradation after 29 d for bottle 1
10 % degradation after 29 d for bottle 2

Any other information on results incl. tables

 

Day

Test substance %

Day

Reference substance %

0

0

0

0

2

1

2

16

5

3

5

41

7

4

7

55

9

4

9

62

14

5

14

72

19

6

19

78

23

6

23

80

27

6

27

81

29

6

29

82

29

6

29

82

29

7

29

82

 

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Interpretation of results:
other: not readily biodegradable
Conclusions:
The test substance was found not to inhibit microbial activity and was not readily biodegradable under the test conditions.
There were no deviations from guideline; validity criteria have been fulfilled.