Benzene, (1-methylethyl)-, oxidized, cumene residues, acetophenone fraction

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study, data based on EU RAR (Phenol, 2006); information on the degradation rates with respect to 10-days window is presented.

Data source

Reference

Reference Type:

publication

Title:

A method to classify biodegradabilities of organic compounds.

Author:

Urano K, Kato Z

Year:

1986

Bibliographic source:

J. Hazard. Mater. 13

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I))

Deviations:

yes

Remarks:

test duration less than 14 d

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Phenol

EC Number:

203-632-7

EC Name:

Phenol

Cas Number:

108-95-2

Molecular formula:

C6H6O

IUPAC Name:

phenol

Details on test material:

no further information

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

- Method of cultivation: semicontinuously cultured by the MITI method with a synthetic sewage
- Pretreatment: no

Duration of test (contact time):

10 d

Initial test substance concentration

Initial conc.:

100 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of medium: K2HPO4 25.75 g/L; KH2PO4 8.5 g/L; Na2HPO4 * 12 H2O 44.6 g/L; NH4Cl 1.7 g/L; MgSO4 * 7 H2O 22.5 g/L; CaCl2 27.5 g/L; FeCl3 * 6 H2O 0.25 g/L
- sludge: 30 mg/L; the sludge for the seeding had been semicontinuously cultured by the MITI method with a sysnthetic sewage
of the following compostion: Glucose 25 g/L; Peptone 25 g/L; corn steep liquor 16 mL/L; KH2PO4 25 g/L; NaOH 16 g/L.
- Temperature: 20 °C

TEST SYSTEM
- Measuring equipment: electrolytic respirometer

Results and discussion

% Degradation

Parameter:

% degradation (O2 consumption)

Value:

62

Sampling time:

100 h

Remarks on result:

other: Concentration: 100 mg phenol/L

Details on results:

phenol concentration t1 (lag phase) k t[h] (degradation time) BOD/ThOD DOCd/DOC0
(mg/l) (h) (h-1) (h)
100 20 0.028 100 0.62 0.09
30 15 0.037 90 0.70 0.06
10 15 0.041 90 0.60 0.07

BOD5 / COD results

Results with reference substance:

no information

Any other information on results incl. tables

no further information

Applicant's summary and conclusion

Validity criteria fulfilled:

not specified

Interpretation of results:

readily biodegradable

Conclusions:

After a test period of 100 h, phenol (100 mg/L resulted in a biological O2-consumption of 62 % of the ThOD (theoretical O2 demand). The lag-phase was 20 h. Therefore, phenol is classified as readily biodegradable.

Executive summary:

The biodegradability of phenol (100 mg/L) was investigated in a ready biodegradability test (MITI-Test I, OECD 302C). Activated sludge cultured in the laboratory was applied. 62 % of the initial phenol concentration was degraded within 100 h. The substance can be classified as readily biodegradable.