Registration Dossier

Environmental fate & pathways

Biodegradation in water and sediment: simulation tests

Administrative data

Endpoint:
biodegradation in water: sewage treatment simulation testing
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1994

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 303 B (Simulation Test - Aerobic Sewage Treatment. B. Biofilms)
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Radiolabelling:
no

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge (adaptation not specified)
Details on source and properties of surface water:
None given.
Details on source and properties of sediment:
The activated sludge was exposed under aerobic conditions to 733 mg/l L-ascorbic acid and was monitored for 15 days.
Duration of test (contact time):
15 d
Initial test substance concentration
Initial conc.:
733 mg/L
Based on:
test mat.
Parameter followed for biodegradation estimation:
DOC removal

Results and discussion

% Degradation
Key result
% Degr.:
97
Parameter:
DOC removal
Sampling time:
5 d
Transformation products:
not measured

Any other information on results incl. tables

Test Results:

Day

% Deg. Test 1

% Deg. Test 2

Mean % Deg.

1

48

57

52.5

5

97

97

97

7

98

97

97.5

9

98

99

98.5

12

99

99

99

15

100

100

100

Applicant's summary and conclusion

Conclusions:
L-ascorbic acid shows 97% biodegradability after 5 days and 100% biodegradablility after 15 days.
Executive summary:

The aerobic biodegradability of L-ascorbic acid was tested using the modified Zahn-Wellens method. A mixture of activated sludge was exposed to 733 mg/l L-ascorbic acid and it was monitored for 15 days to determine the DOC values. The % biodegradation was 97% after 5 days and 100% after 15 days. Therefore, the substance is fully biodegradable.