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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:
26 Jan 2006 - 23 Feb 2006
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

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

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I))
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
liquid
Specific details on test material used for the study:
SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: 09891502
- Physical Appearance: colourless liquid
- Purity: 99.51%
- Storage condition of test material: at room temperature and in the dark

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, domestic, adapted
Details on inoculum:
- Storage conditions: 24.6 - 25.1 °C
- Storage length: 28 days
- pH: 6.4 - 8.6
- Concentration of sludge: 30mg/L
- Amount: 2.428mL
Duration of test (contact time):
28 d
Initial test substance concentration
Initial conc.:
100 mg/L
Based on:
test mat.
Details on study design:
TEST CONDITIONS
- Test temperature: 24.8 - 25.5 °C
- pH: 5.9 - 8.6
- pH adjusted: no
- Suspended solids concentration: 1000 mg/L
- Continuous darkness: yes/no

TEST SYSTEM
- Culturing apparatus: Cultivation tank
- Measuring equipment: Gas chromatograph, TOC meter, GC/MS system, IR spectrophotometer, coulomter, pH meter

SAMPLING
- Sampling frequency: 7 days

Results and discussion

% Degradationopen allclose all
Key result
Parameter:
% degradation (O2 consumption)
Value:
29.7
Sampling time:
28 d
Key result
Parameter:
% degradation (DOC removal)
Value:
33.1
Sampling time:
28 d
Key result
Parameter:
other: GC
Value:
100
Sampling time:
28 d

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The percentage biodegradation by BOD and DOC were similar, while that obtained by GC resulted in a comparatively high value. The percentages of the metabolites remaining were estimated.

The remaining metabolite was identified (4-carboxyl-2-ethyl-2-methyl-1,3-dioxolane). This metabolite was oxidised from 4-hydroxymethyl-2-ethyl-2-methyl-1,3-dioxolane, one of the two hydrates of test item, the other being acrylic acid. Acrylic acid is readily biodegradable substance and disappear from the test solution, while 4-hydroxymethyl-2-ethyl-2-methyl-1,3-dioxolane and 4-carboxyl-2-ethyl-2-methyl-1,3-dioxolane remained.