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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:
other information
Reliability:
1 (reliable without restriction)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2006

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
EU Method C.4-D (Determination of the "Ready" Biodegradability - Manometric Respirometry Test)
GLP compliance:
yes

Test material

Constituent 1
Chemical structure
Reference substance name:
-
EC Number:
465-070-0
EC Name:
-
Cas Number:
518048-03-8
Molecular formula:
C16H19FN403
IUPAC Name:
2-(1-amino-1-methylethyl)-N-(4-fluorobenzyl)-5-hydroxy-1-methyl-6-oxo-1,6-dihydropyrimidine-4-carboxamide
Details on test material:
Free Amine Batch Code # 200601180120.

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, industrial, adapted
Details on inoculum:
The activated sludge was collected from the aeration tank of a civil wastewater treatment plant, washed by centrifugation, the supemalant liquid decanted and the solid material re-suspended in tap water. The washing procedure was repeated three times. A homogenized aliquot of the final sludge suspension has been weighted, dried, and the ratio of wet to dry weight was calculated.
Before using it, the sludge was diluted with test water to a concentration of 15 mg/L (dry weight basis).
Duration of test (contact time):
11 d
Initial test substance concentration
Initial conc.:
100 mg/L
Based on:
other: nominal concentrations
Parameter followed for biodegradation estimation
Parameter followed for biodegradation estimation:
O2 consumption
Details on study design:
The assay on test item has been run in parallel with a ready biodegradable reference substance (Sodium Benzoate), the inoculum control, the abiotic control containing the test item and a sterilizing agent (HgCl2), and the toxicity control containing test item, reference compound and inoculum.
BOD flasks of 500 ml capacity, equipped with pressure sensors fitted on the bottle mouth, have been used as test units.
Reference substance
Reference substance:
benzoic acid, sodium salt

Results and discussion

Test performance:
Conditions for the validity of the test :
- the oxygen demand of the inoculum control is normally 20-30 mgO2/L and should not be greater than 60 mgO2/L within 28 days.
- the degradation rates of the two test flasks containing the test item, test water and inoculum should not deviate by more than 20% at the time the plateau is reached, at the end of the test or at the end of the 10-day window
- the percentage degradation of the reference item must reach the pass level for ready biodegradation ( at least 60% of ThOD) within the 10-days window (ThOD = Theorical Oxygen demand)
% Degradationopen allclose all
Parameter:
% degradation (O2 consumption)
Value:
0
Sampling time:
1 d
Parameter:
% degradation (O2 consumption)
Value:
-1.3
Sampling time:
2 d
Parameter:
% degradation (O2 consumption)
Value:
2.9
Sampling time:
3 d
Parameter:
% degradation (O2 consumption)
Value:
3.2
Sampling time:
4 d
Parameter:
% degradation (O2 consumption)
Value:
2.2
Sampling time:
5 d
Details on results:
%Degradation : 3.8 at 6 d
%Degradation : 2.9 at 7 d
%Degradation : 4.5 at 8 d
%Degradation : 5.1 at 11 d

BOD5 / COD results

Results with reference substance:
Day # - % Degradation
1 - 30
2 - 43.8
3 - 61.2
4 - 69.0
5 - 78.6
6 - 87.6
7 - 97.2
8 - 106.2
11 - 121.8

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Interpretation of results:
not inherently biodegradable
Conclusions:
The test item Free Amine has shown to be not ready biodegradable under the conditions applied in a Manometric Respirometry test, having not reached the pass level (60% biodegradation) but showing a percentage degradation around of 5% at the end of the 10-day window.