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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:
1999-08-31 to 1999-12-03
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: OECD study under GLP

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1999
Report date:
1999

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 301 A (Ready Biodegradability: DOC Die Away Test)
GLP compliance:
yes

Test material

Constituent 1
Reference substance name:
Silicophosphonat
IUPAC Name:
Silicophosphonat
Details on test material:
- Name of test material (as cited in study report): Silicophosphonat
- Physical state: Liquid

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, domestic, non-adapted
Details on inoculum:
Activated sludge from laboratory wastewater plants treating municipal sewage. Concentration of dry substance 30 mg/L
Duration of test (contact time):
28 d
Initial test substance concentrationopen allclose all
Initial conc.:
193 mg/L
Based on:
test mat.
Initial conc.:
20 mg/L
Based on:
DOC
Parameter followed for biodegradation estimation
Parameter followed for biodegradation estimation:
DOC removal
Details on study design:
TEST CONDITIONS
- Test temperature: not given
- pH: 7.4
- pH adjusted: no

CONTROL AND BLANK SYSTEM
- Inoculum blank: yes
- Control: aniline
- Abiotic control: yes
- Adsorption control: yes
- Inhibition control: yes
Reference substance
Reference substance:
aniline

Results and discussion

Test performance:
valid
% Degradation
Parameter:
% degradation (DOC removal)
Value:
< 10
Sampling time:
28 d
Details on results:
10-day window met: no
Degradation degree of test substance <70% within 28 d: no
Degradation degree of the test substance (28d): <10%
Degradation degree of the inhibiton control after 14 days: 50-60%
Degradation degree of the reference substance after 14 days: 80-90%
Physico-chemical elimination (end of test): <10%
Elimination of the test substance by adsorption (day 5): <10%

BOD5 / COD results

Results with reference substance:
see above

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Interpretation of results:
under test conditions no biodegradation observed
Conclusions:
Teh test substance is in this test poorly biodegradable (not readily biodegradable according to OECD criteria)
Executive summary:

In a OECD 301A test Silicophosphonat was shown to be not readily biodegradable. The biodegradation degree after 28 was <10%. The 10 days window was not passed. The positive control, the inhibiton control, the abiotic control and the adsorption control worked as expected.