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
Study period:
1989-07-03 to 1989-08-08
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Guideline study without detailed documentation

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1996
Report Date:
1996

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 303 A (Simulation Test - Aerobic Sewage Treatment. A: Activated Sludge Units)
Version / remarks:
(1981)
Deviations:
not specified
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
2,2,4(or 2,4,4)-Trimethyladipic acid of Hüls AG, purity typical but not reported
Radiolabelling:
no

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, domestic (adaptation not specified)
Details on source and properties of surface water:
Synthetic sewage was used (based on tap water), for details on composition see below.
Details on source and properties of sediment:
no sediment was used in the test
Details on inoculum:
INOCULUM
- Source: Municipal WWTP Marl-West, sampled 03 July 1989
- Pretreatment: Fed into test apparatus approx. 40 min after sampling
Duration of test (contact time):
3 h
Initial test substance concentration
Initial conc.:
10.2 mg/L
Based on:
DOC
Parameter followed for biodegradation estimation:
DOC removal
Details on study design:
TEST SYSTEM
- Culturing apparatus: Flow-through OECD Confirmatory Unit
- Number of culture flasks per concentration: 1
- Aeration device: Pump
- Measuring equipment: Beckmann DOC analyzer
- Closed vessels used: no

SAMPLING: DOC determination daily (except weekends) after mixing of 24  hour collected effluent 

TEST CONDITIONS
- Flow rate: 1 l/hour; mean retention time: 3 hours.
- Test temperature: 21 +- 2 °C

DURATION OF THE TEST: 36 days

Results and discussion

Mean total recovery
Compartment:
other: water / sediment, material (mass) balance
Remarks on result:
other: no data available
% Degradation
% Degr.:
48.22
St. dev.:
3.15
Parameter:
DOC removal
Sampling time:
36 d
Transformation products:
not measured
Evaporation of parent compound:
not specified
Volatile metabolites:
not specified
Residues:
not specified

Applicant's summary and conclusion

Validity criteria fulfilled:
not specified
Conclusions:
The mean degree of elimination of 2,2,4(or 2,4,4)-trimethyladipic acid at the plateau phase was 48.2% (CL: 45.1-51.4%) at a contact time of 3 hours.
Executive summary:

The ultimate biodegradation of 2,2,4(or 2,4,4)-trimethyladipic acid was determined by aerobic micro-organisms in a continuously operated test system simulating the activated sludge process according to OECD TG 303 A (1981). The DOC was determinded in frequently taken samples of the effluents over a period of 36 days. The mean degree of elimination of test substance at the plateau phase was 48.2% (CL: 45.1-51.4%) at a contact time of 3 hours indicating that degradation took place.

The study was assessed as "reliable with restrictions".