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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:
07 January - 05 February 2009
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP Guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2009
Report Date:
2009

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Benzene, 1,1'-(1,2-ethanediyl)bis-, brominated; SH-1
- Substance type: white powder
- Physical state: solid
- Analytical purity: >99%
- Lot/batch No.: 20081010
- Expiration date of the lot/batch: 08 January 2011
- Storage condition of test material: stable; at room temperature in the dark

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, domestic, non-adapted
Details on inoculum:
- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): The source of test organ isms was activated sludge freshly obtained from a municipal sewage treatment plant: ‘Waterschap de Maaskant‘, ‘s-Hertogenbosch, The Netherlands, receiving predominantly domestic sewage.
Duration of test (contact time):
29 d
Initial test substance concentration
Initial conc.:
87.7 - 87.9 mg/L
Based on:
test mat.
Parameter followed for biodegradation estimation
Parameter followed for biodegradation estimation:
CO2 evolution
Details on study design:
TEST CONDITIONS
- Composition of medium:
Stock solutions of mineral components:
A) 8.50 g KH2PO4
21.75 g K2HPO4
67.20 g Na2HPO4*12H2O
0.50 g NH4CI
dissolved in MiIIi-Q water and made up to 1 litre,
pH 7.4 ± 0.2
B) 22.50 g MgSO4.7H20 dissolved in MiIIi-Q water and made up to 1 litre.
C) 36.40 g CaCI2.2H20 dissolved in Milli-Q water and made up to 1 litre.
D) 0.25 g FeCI3.6t-120 dissolved in Milli-Q water and made up to 1 litre.

Mineral medium: 1 litre mineral medium contains: 10 ml of solution (A), 1 ml of solutions (8) to CD) and Milli-RO water.
Barium hydroxide: 0.0125 M Ba(OH)2(Boom, The Netherlands), stored in a sealed vessel to prevent absorption of CO2 from the
air,
Synthetic air (CO2 < 1 ppm): A mixture of oxygen (ca. 20%) and nitrogen (ca. 80%) was passed through a bottle, containing 0.5 - 1 litre 0.0125 M 8a(OH)2 solution to trap CO2 which might be present in small amounts. The synthetic air was sparged through the scrubbing solutions at a rate of approximately 1-2 bubbles per second (ca. 30-100 ml/min).

- Test temperature: 21.4 -22.3
- pH: 7.6 - 7.9



TEST SYSTEM
- Culturing apparatus: 2 litre all-glass brown coloured bottles
- Number of culture flasks/concentration:
Test suspension: containing test substance and inoculum (2 bottles).
Inoculum blank: containing only inoculum (2 bottles)
Positive control: containing reference substance and inoculum (1 bottle).
Toxicity control: containing test substance, reference substance and inoculum (1 bottle),



SAMPLING
- Sampling frequency: Titrations were made every second or third day during the first 10 days, and thereafter at least every fifth day until the 28th day, for the inoculum blank and test suspension. Titrations for the positive and toxicity control were made at least 14 days.



CONTROL AND BLANK SYSTEM
- Inoculum blank: yes
- Abiotic sterile control: yes
- Toxicity control: yes



Reference substance
Reference substance:
acetic acid, sodium salt
Remarks:
sodium acetate

Results and discussion

% Degradation
Parameter:
% degradation (CO2 evolution)
Value:
0 - 1
Sampling time:
29 d

Any other information on results incl. tables

SH-1 was not readily biodegradable under the conditions ofthe modified Sturm test presently performed.

The relative biodegradation values calculated from the measurements performed during the test period revealed no significant biodegradation of SH-1.

In the toxicity control more than 25% biodegradation occurred within 14 days (30%, based on ThCO2). Therefore, the test substance was assumed not to inhibit microbial activity.

Applicant's summary and conclusion

Interpretation of results:
under test conditions no biodegradation observed
Conclusions:
The test substance was not readily biodegradable under the conditions of the modified Sturm test presently performed.