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Environmental fate & pathways

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: Conducted at GLP-accredited facility to current guidelines

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2017
Report date:
2017

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)
Deviations:
no
GLP compliance:
yes (incl. QA statement)

Test material

Constituent 1
Test material form:
liquid

Study design

Inoculum or test system:
activated sludge, domestic (adaptation not specified)
Details on inoculum:
Activated sludge from the municipal wastewater treatment plant Breisgauer Bucht (Forchheim, Germany) was used as inoculum with a concentration corresponding to 30 mg dry solids per litre. The treatment plant clarifies predominantly domestic wastewater of the region of Freiburg and has a capacity of 600.000 inhabitant equivalents. Sampling date of activated sludge was 2 November 2016. Dry solid of the activated sludge was determined as 3.9 g/L by weight measurements after 3 h drying at 105 °C (mean of triplicate measurements). The activated sludge was washed twice with tap water by settling the sludge, decanting the supernatant and re-suspending the sludge.
Duration of test (contact time):
28 d
Initial test substance concentration
Initial conc.:
>= 97.8 - <= 99.4 mg/L
Based on:
ThOD
Parameter followed for biodegradation estimation
Parameter followed for biodegradation estimation:
CO2 evolution
Reference substance
Reference substance:
acetic acid, sodium salt

Results and discussion

% Degradation
Key result
Parameter:
% degradation (CO2 evolution)
Value:
ca. 3.8
Sampling time:
28 d

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Interpretation of results:
not readily biodegradable
Conclusions:
The degradation extent of the test item at the end of the test was -3.8% (mean of three replicates).
The criterion for ready biodegradation was not met (degradation ≥ 60% and fulfilment of 10-d-window) therefore the test item is not ready biodegradable according to the OECD criteria.
Executive summary:

The degradation extent of the test item at the end of the test was -3.8% (mean of three replicates).

The criterion for ready biodegradation was not met (degradation ≥ 60% and fulfilment of 10-d-window) therefore the test item is not ready biodegradable according to the OECD criteria.