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Environmental fate & pathways

Biodegradation in water: screening tests

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Administrative data

Endpoint:
biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1990
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Study comparable to OECD Guideline 301C.

Data source

Reference
Reference Type:
publication
Title:
Determination of Monod kinetics of toxic compounds by respirometry for structure-biodegradability relationship
Author:
Desai S, Govind R, Tabak H
Year:
1990
Bibliographic source:
ACS Symp. Ser. 422: 142-156

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I))
Deviations:
not specified
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, domestic, non-adapted
Details on inoculum:
- Source of inoculum/activated sludge: predominantly domestic sewage sludge
- Concentration of sludge: 30 mg/L of sludge (dry matter)
Duration of test (contact time):
20 - 40 d
Initial test substance concentration
Initial conc.:
100 mg/L
Reference substance
Reference substance:
aniline

Results and discussion

% Degradation
Parameter:
% degradation (O2 consumption)
Value:
> 80 - < 95
Sampling time:
40 d
Remarks on result:
other: readily biodegradable
Details on results:
First order biodegradation constant (hr-1): ln k = -6.089
Maximum specific substrate uptake rate per unit biomass km = 10.0 / day (Aniline 16.1, Phenol 16.9).

Although the oxygen uptake curves were not presented, it was reported that all test compounds revealed a lag phase, biodegradation phase and the plateau region within a period of 10 days, proving that the 10-day window criteria is met.

BOD5 / COD results

Results with reference substance:
Degradation of aniline >=60 % within 28 days

Applicant's summary and conclusion