Registration Dossier

Environmental fate & pathways

Biodegradation in water: screening tests

Currently viewing:

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:
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

Reference
Name:
Unnamed
Type:
Constituent
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.