2,2,4(or 2,4,4)-trimethyladipic acid

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

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

Test material information

Constituent 1

Reference substance name:

2,2,4(or 2,4,4)-trimethyladipic acid

EC Number:

258-556-7

EC Name:

2,2,4(or 2,4,4)-trimethyladipic acid

Cas Number:

53445-37-7

Molecular formula:

C9H16O4

IUPAC Name:

2,2,4-trimethylhexanedioic acid; 2,4,4-trimethylhexanedioic acid

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

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".