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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
Study period:
2008
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
comparable to guideline study with acceptable restrictions

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2008
Report Date:
2008

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)
Deviations:
no
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Details on test material:
- Name of test material (as cited in study report): Sepisol fast Blue 85219
- Substance type: organic salt - UVCB
- Appearance/Physical state: dark blue powder
- Stability under test conditions: stable
- Storage condition of test material:room temperature
Specific details on test material used for the study:
- Batch N°: 310551

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, domestic (adaptation not specified)
Duration of test (contact time):
ca. 28 d
Initial test substance concentrationopen allclose all
Initial conc.:
10 mg/L
Based on:
other: TOC (total organic carbon)
Initial conc.:
15.1 mg/L
Based on:
test mat.
Parameter followed for biodegradation estimation
Parameter followed for biodegradation estimation:
CO2 evolution
Details on study design:
TEST CONDITIONS
- Test temperature:20 °C +/- 2


TEST SYSTEM
- Details of trap for CO2 and volatile organics if used:the barium hydroxide absorber closesy to the test vessel was disconneted and titrate thanks to sulfochromic oxidation (NF ISO 14235).


SAMPLING
- Sampling frequency:
- Sampling method:
- Sterility check if applicable:
- Sample storage before analysis:
- Other:

Reference substance
Reference substance:
acetic acid, sodium salt

Results and discussion

Test performance:
The CO2 quantity produced by the "blank control" is 22,5 mg at the end of the 28th day. This result is below the admitted threshold of 40 mg
The sample made of the test material and the referebce substance (sodium acetate) is biodegraded at 28% following a 14 days period.
Toxicity check: combined degradation of 28% for the reference and test substances, indicating the test substance was not toxic to the microbial
populations in the inoculum.
% Degradation
Key result
Parameter:
% degradation (CO2 evolution)
Value:
45
Sampling time:
28 d

BOD5 / COD results

Results with reference substance:
95% of biodegradation after 28 days of test
% of biodegradation is higher than 60 % at the 14th day (75%)

Any other information on results incl. tables

The following results are presented as the mean of the two assays:

 

Number of days

1

2

6

9

12

14

16

19

21

23

28

28*

Control : Na acetate

13.3

6.6

8.5

3.8

11.9

4.6

6.6

0.7

0.2

4.6

4.84

4.18

Blue 85219

10 mg/L of TOC

3.0

1.65

9.0

2.4

2.1

1.3

3.0

2.5

0.7

2.4

3.9

3.4

Inhibition

Control

11.1

8.36

4.6

5.2

2.1

1.3

3.0

1.7

0.3

2.8

3.1

3.3

Blank control

2.2

1.65

1.8

2.4

2.1

1.3

3.0

0.3

0.0

1.9

3.1

2.5

 

 

Number of days

Corrected CO2

1

2

6

9

12

14

16

19

21

23

28

28*

Control : Na acetate

11.1

5.0

6.7

1.4

9.8

3.3

3.6

0.4

0.2

2.8

1.8

1.7

Blue 85219

10 mg/L of TOC

0.9

0.0

7.2

0.0

0.0

0.0

0.0

2.2

0.7

0.6

0.8

0.9

Inhibition

Control

8.9

6.7

2.8

2.9

0.0

0.0

0.0

1.3

0.3

1.0

0.0

0.8

CO2 produced in mg following “removal” of the “blank control” values

 

 

 

Number of days

0

2

6

9

12

14

16

19

21

23

28

28*

Reference compounds

0%

22%

32%

48%

68%

75%

82%

83%

83%

89%

92%

95%

Blue 85219

10 mg/L of TOC

0%

3%

3%

28%

28%

28%

28%

36%

38%

40%

42%

45%

Inhibition

Control

0%

11%

20%

27%

27%

27%

27%

29%

29%

30%

30%

31%

Degradation percentage comparing ThCO2

*after adding hydrochloric acid to each test vessel to drive off the carbon dioxide present in the test suspensions (left as carbonates and bicarbonates)

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Interpretation of results:
not readily biodegradable
Conclusions:
Under the test condition, the biodegradation percentage of the test material (10 mg/L of TOC) has been assessed as 45% after a 28 days period of incubation. The reference substance, sodium acetate, reached a level of 95% on the same test period. According the guideline OCDE 301, the degradation has failed to reach the 60 % thresholf and this is not considered to be readily biodegradable.
Executive summary:

The test item Sepisol Fast Blue 85219 was tested using the OCDE method 301B (CO2 evolution) also named Modified Sturm Test.

Activated sludge from domestic wastewater treatment plant was used.

15,1 mg/L of the test material (corresponding to a TOC of 10mg/L) was added to the mineral medium.  

The theoric CO2 quantity was calculated to be 29 mg (= ThCO2). No organic solvents were used to facilitate the dispersion of the test material.

Each test vessel was connected to a series of 4 absorption bottles, 3 of them containing 4g/L of barium hydroxyde solution and one containing a sodium hydroxide solution. The test was started by bubbling CO2-free air through the suspensions.

CO2 evolution from the test suspensions, inoculum blanks and the reference substance were followed in parallel.

Controls: blank and positive controls (sodium acetate), abiotic and toxicity cheks were included. Sodium acetate was used as the positive control.

Analytical method: for measurement of evolved C02, the barium hydroxide absorber closesy to the test vessel was disconneted and titrate thanks to sulfochromic oxidation (NF ISO 14235).

Under the test condition, the biodegradation percentage of the test material (10 mg/L of TOC) has been determined as 45% after a 28 days period of incubation. The reference substance, sodium acetate, reached a level of 95% on the same test period. According the guideline OCDE 301, the degradation has failed to reach the 60 % threshold and the test item is not considered to be readily biodegradable.