Dimethylaminopropylmethacrylamide, dodecyl bromide

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

Study period:

22/03/2016 - 21/10/2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)

Version / remarks:

1992

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

The study was performed using aerobic activated sludge from BRIANZACQUE civil wastewater treatment plant. The sludge were collected on March 23, 2016. An homogenized aliquot of the wet sludge was centrifuged, the supernatant was removed while the solid phase was weighed, dried and the ratio of wet to dry weight was calculated to be equal to
10.95 %.
Based on this ratio, calculated amounts of wet sludge was centrifuged, the supernatant was removed and the solid phase was suspended in the test medium to get a concentration equivalent to 3 g dry material per litre.
The prepared sludge inoculum was pre-conditioned to the experimental conditions by
aerating it in the dark. The concentrated suspension was used as inoculum to give a final concentration of 15 mg dry material per litre into test flasks.

Duration of test (contact time):

28 d

Initial conc.:

79.15 mg/L

Based on:

ThOD

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

The study was performed using aerobic activated sludge from BRIANZACQUE civil wastewater treatment plant. The sludge were collected on March 23, 2016. An homogenized aliquot of the wet sludge was centrifuged, the supernatant was removed while the solid phase was weighed, dried and the ratio of wet to dry weight was calculated to be equal to 10.95 %.
Based on this ratio, calculated amounts of wet sludge was centrifuged, the supernatant was removed and the solid phase was suspended in the test medium to get a concentration equivalent to 3 g dry material per litre.
The prepared sludge inoculum was pre-conditioned to the experimental conditions by aerating it in the dark. The concentrated suspension was used as inoculum to give a final concentration of 15 mg dry material per litre into test flasks.
The assay on test item was carried out in parallel with the following bottles:
- A known ready biodegradable reference item (one replicate), Sodium Benzoate, at 100.0 mg/L;
- Two inoculum control replicates (blank);
- Two test item replicates at 35.0 mg/L concentration;
- One abiotic control containing the test item at 35.0 mg/L and a sterilizing agent (HgCl2) at 100.0 mg/L (without inoculum);
- One toxicity control, containing the test item at 35.0 mg/L and reference item at 100.0 mg/L.
BOD flasks of 500 mL capacity, equipped with pressure sensors fitted on the bottle mouth, were used as test units.
The method is based on an electro-chemical analyses process. The biodegradation process consumes the dissolved oxygen in liquid and generates CO2. Evolved carbon dioxide is adsorbed by potassium hydroxide and the total pressure decreases in the test flasks. The pressure decrease is detected and converted into an electrical signal by means of an ctrode type manometer.

Reference substance:

benzoic acid, sodium salt

Key result

Parameter:

% degradation (O2 consumption)

Value:

85.6

Sampling time:

28 d

Results with reference substance:

The reference substance achieved 80.2% degradation in 28 days.

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

The substance achieved 85.6% biodagradation in 28 days in a test according to OECD 306F. Based on this, the substance is considered readily biodgradable.

Description of key information

The substance achieved 85.6% biodagradation in 28 days in a test according to OECD 306F . Based on this, the substance is considered readily biodgradable.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Type of water:

freshwater