Isobutyrophenone

Biodegradation in water: screening tests

Administrative data

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

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 310 (Ready Biodegradability - CO2 in Sealed Vessels (Headspace Test)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Isobutyrophenone

EC Number:

210-275-0

EC Name:

Isobutyrophenone

Cas Number:

611-70-1

Molecular formula:

C10H12O

IUPAC Name:

2-methyl-1-phenylpropan-1-one

Details on test material:

- Name of test material (as cited in study report): Isobutyrophenone (TK 40392)
- Physical state: colorless, clear liquid
- Analytical purity: 99.2 area -%
- Batch No.: 090727T102
- Storage condition of test material: Storage at room temperature

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge: Municipal activated sludge from the wastewater treatment plant of Mannheim, Germany
- Preparation of inoculum for exposure: A suitable aliquot of the 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 control the activated sludge suspension was aerated with carbon dioxide free air for about 48 hours at 22 ± 2° C. Aeration was stopped and the sludge was allowed to settle. The supernatant was discarded and the residue of the sludge suspension was filled up with tap water. The sludge of the suspension was adjusted to a concentration 800 mg/L of dry weight. Aliquots of 0.5 ml were added to the test vessels to obtain a sludge concentration of 4 mg/L dry substance in the test assays.
- Concentration of sludge: 4 mg/L

Duration of test (contact time):

28 d

Initial test substance concentration

Initial test substance concentration 1

Initial conc.:

25 mg/L

Based on:

test mat.

Initial test substance concentration 2

Initial conc.:

20 mg/L

Based on:

other: TOC

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

TOC removal

Details on study design:

TEST CONDITIONS
- Composition of medium: 100 ml test medium containing 2.5 µl/L test substance, 90 ml mineral medium, 0.5 ml inoculum and 9.5 ml water

TEST SYSTEM
- Culturing apparatus: 160 ml incubation bottles filled up to a volume of 100 ml
- Number of culture flasks/concentration: 3

SAMPLING
- Sampling frequency: at day 2, 8, 12, 14, 16

CONTROL AND BLANK SYSTEM
- Blank control: 3 replicates
- Reference item: 3 replicates
- inhibition control: 3 replicates

Reference substance

Reference substance:

aniline

Results and discussion

% Degradation

Parameter:

% degradation (TOC removal)

Value:

ca. 90

Sampling time:

21 d

Details on results:

- Duration of adaption phase 3 days
- Degree of biodegradation of the test substance at the end of the ten-days window, mean value: 70 - 80% TIC/TOC
- Degree of elimination of the test substance at physical chemical control at the end of exposure, mean value: <10% TIC/TOC
- Degree of biodegradation in the inhibition control after 21 days, mean value: 90% TIC/TOC

BOD5 / COD results

Results with reference substance:

Degree of biodegradation of the reference substance after 14 days, mean value: 78% TIC/TOC

Applicant's summary and conclusion

Interpretation of results:

readily biodegradable