(Z)-4-[C11-13 (branched) alkylamino]-4-oxo-2-butenoic acid

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Details on inoculum:

- Origin of inoculum: municipal activated sludge from the wastewater treatment plant of Mannheim, Germany. The inoculum was collected from the aeration tank of the plant and aerated in the laboratory until use.
- Preparation of inoculum: a suitable aliquot of the activated sludge suspension was sieved by a finely woven mesh with a mesh size of about 1 mm. To reduce the content of inorganic carbon in the blank controls, the activated sludge was aerated with carbon dioxide free air for about 24 h at 22 +/- 2°C. On the day of exposure the suspension was washed once with tap water. In order to do that the aeration was stopped and the sludge was allowed to settle. After settling the supernatant was discarded, the remaining sludge suspension was filled up with tap water and the concentration of the sludge was adjusted to 6.0 g/L dry weight. Aliquots of 7.5 mL were added to the test vessels to obtain an activated sludge concentration of 30 mg/L dry weight.

Duration of test (contact time):

28 d

Initial conc.:

ca. 29 mg/L

Based on:

test mat.

Initial conc.:

20 mg/L

Based on:

other: TOC

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST SYSTEM
- Test vessels: 2 L incubation bottles filled up to a volume of 1.5 L
- pH-value: adjusted to 7.4 +/- 0.2
- Aeration: at beginning of exposure the test vessels were connected with an aeration unit and aerated with carbon dioxide free air
- Test assays were stirred using magnetic stirrers
- The following test assays were prepared: 2 blank control assays (BC)
2 test substance assays (TS)
1 inhibition control test assay (IH)
1 reference substance assay (RS)

Reference substance:

aniline

Parameter:

% degradation (DOC removal)

Value:

< 10

Sampling time:

28 d

Details on results:

- Degree of biodegradation in the inhibition control after 14 d: 39 % CO2/ThCO2

Results with reference substance:

- Degree of biodegradation of the reference substance after 14 d: 83 % CO2/ThCO2

Validity criteria fulfilled:

yes

Interpretation of results:

other: poorly biodegradable

Description of key information

Poorly biodegradable.

Additional information

The ready biodegradability of the substance was tested in a GLP guideline test following OECD 301B [BASF SE 2012]. The biodegradation rate was determined by measuring the CO2 evolution of domestic activated sludge at a test substance concentration of 29 mg/L. After 28 days incubation time a degradation rate of 0 -10 % was determined.

A second biodegradation study is available which has been conducted according to OECD guideline 301F [BASF AG 1998]. This time, the biodegradation rate was determined by measuring the O2 consumption of the activated sludge at a test substance concentration of 100 mg/L. At test termination after 28 days a degradation rate of 10 - 20 % was determined.