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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:
1995
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1995
Report Date:
1995

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I))
Deviations:
not specified
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge (adaptation not specified)
Details on inoculum:
The standard activated sludge purchased from Chemical Safety Center, Chemicals Inspection & Testing Institute, on April 20, 1995, was used.
Duration of test (contact time):
28 d
Initial test substance concentration
Initial conc.:
100 mg/L
Based on:
test mat.
Parameter followed for biodegradation estimation
Parameter followed for biodegradation estimation:
O2 consumption
Details on study design:
TEST CONDITIONS
- Composition of medium: according to JIS 0102-21(1)
- Test temperature: 25.0-26°C
- pH: 6.99 - 7.27
- Suspended solids concentration: 30mg/L
- Test soliution: 300mL


TEST SYSTEM
- Culturing apparatus: Closed system oxygen consumption meter, Okura Electric Co, Ltd " Coulometer OM-2000"
- Number of culture flasks/concentration: 3

SAMPLING
- Sampling frequency: direct measuremet of test substance concentration: after 28 days
- Sampling frequency: direct measuremet of test substance concentration: after 7, 14, 21, 28 days

CONTROL AND BLANK SYSTEM
- Inoculum blank (basic respiration chamber: mineral medium + inoculum): 1 vessel
- water stability chamber (test substance in mineral medium): 1 vessel


Observations: Color of the solution, degree of growth of the standard activated sludge, dissolution status of the test substance, pH
Reference substance
Reference substance:
aniline

Results and discussion

% Degradationopen allclose all
Key result
Parameter:
% degradation (O2 consumption)
Value:
0.2
Sampling time:
28 d
Key result
Parameter:
% degradation (test mat. analysis)
Value:
1.1
Sampling time:
28 d
Details on results:
Degradation based on oxygen consiumption: 0.2, -1.9, 0.0%
Degradation based on measurement of residual test substance concentration: 0.7, 1.1, 0.6%

Validity criteria:
- inoculum blank oxygen uptake (28d) 12.8mg/0.3L- validity criterion fulfilled (< 60mg/L)
- pH 6.99 - 7.27 - validity criterion fullfilled (6-8.5)
- degradation of aniline calculated from the oxygen consumption exceeds after 7 days 57.5 % and after 14 days 68.5% - validity criterion fullfilled (> 40% and > 65%, respectively)
- replicate values of the removal of the test substance at the plateau or at the end of the test < 20% - not applicable as no biodegradation observed

BOD5 / COD results

Results with reference substance:
73.8% degradation after 28 days

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Interpretation of results:
under test conditions no biodegradation observed