Ferrate(1-), [[N,N'-1,2-ethanediylbis[N-[[2-(hydroxy-.kappa.O)phenyl]methyl]glycinato-.kappa.N,.kappa.O]](4-)]-, sodium (1:1), (OC-6-13)-

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: screening test, other

Remarks:

inherent biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study, basic information available by the test report

Qualifier:

according to guideline

Guideline:

OECD Guideline 302 B (Inherent biodegradability: Zahn-Wellens/EMPA Test)

Deviations:

no

GLP compliance:

no

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
No surrogate or analogue material was used.

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, adapted

Details on inoculum:

- Source of activated sludge: aeration tank of the sewage treatment plant "Aquanet S.A., Centralna Oczyszczalnia, Scieków ul. Gdynska 1, Kozieglowy
- Date of collection: 2010-03-15
- Pretreatment: Washing twice, centrifugation for separation of the sludge
- Concentration of activated sludge in reaction mixture: 0.3 g ss/L

Duration of test (contact time):

28 d

Initial conc.:

100 mg/L

Based on:

DOC

Parameter followed for biodegradation estimation:

DOC removal

Details on study design:

TEST CONDITIONS
- Test temperature: 20 - 25 °C
- Aeration of dilution water: yes
- Suspended solids concentration: 0.3 g ss/L medium
- Continuous darkness: yes

TEST SYSTEM
- Test suspension: mineral medium, test substance and inoculum
- Procedure control: mineral medium, reference substance and inoculum
- Inoculum blank: mineral medium and inoculum
- Toxicity control: mineral medium, test substance, reference substance and inoculum
- Test volume: 1000 mL
- Chemical analysis: Determination of dissolved total organic carbon (DOC)
- Test apparatus: Spectrophotometer CADAS Dr. Lange

SAMPLING
- Sampling frequency: daily

Reference substance:

other: Sodium benzoate

Preliminary study:

Not applicable.

Test performance:

Neither unusual observations during test nor any other information affecting results are reported.

Parameter:

% degradation (DOC removal)

Value:

1.5

Sampling time:

7 d

Parameter:

% degradation (DOC removal)

Value:

3.2

Sampling time:

14 d

Parameter:

% degradation (DOC removal)

Value:

5.3

Sampling time:

21 d

Parameter:

% degradation (DOC removal)

Value:

7.1

Sampling time:

27 d

Parameter:

% degradation (DOC removal)

Value:

8.2

Sampling time:

28 d

Details on results:

No toxic effects to bacteria were observed.

Results with reference substance:

The reference compound reached the level of greater or equal to 70 % degradation within 14 days, since at this time point, 98 % degradation has had occurred.

Validity criteria fulfilled:

yes

Remarks:

Validity criteria of the applied guideline were met.

Interpretation of results:

not inherently biodegradable

Conclusions:

The study report describes about a valid biodegradation study according to OECD Guideline 302 B (Zahn-Wellens/EMPA Test). According to the obtained degradation of 8.2 % after 28 days, the test substance is considered as not inherently biodegradable.

Executive summary:

The biodegradation potential of Fe(III)HBED was investigated according to OECD Guideline 302 B (Chojnacka, 2010). Activated sludge was used as inoculum and mixed with the test substance and mineral medium in 2 parallels. Further flasks were the procedure control (with the reference substance sodium benzoate), the inoculum blanks (each in 2 parallels) and one toxicity control (containing mineral medium, test substance, reference substance and inoculum). The suspended solid concentration was 0.3 g ss/L in each flask. The mixtures were agitated and aerated at 20 - 25 °C in the dark for a period of 28 days. The biodegradation process is monitored by determination of dissolved total organic carbon (DOC) with a spectrophotometer in filtered samples taken in daily intervals. The ratio of eliminated DOC, corrected for blank after each time interval, to the initial DOC value is expressed as the % biodegradation at the sampling time. The reference item attained 98 % degradation already after 14 days incubation, thereby fulfilling the validity criteria of the applied guideline, concluding that more or equal to 70 % degradation should have been occurred after 14 days. The test substance showed no toxic effects towards the used bacteria, since the toxicity control attained 55 % degradation after 28 days. The DOC content of the blank was below 10 mg/L at the start of the experiment. The test substance attained 3.2 % degradation after 14 days and 8.2 % degradation after 28 days, respectively. The test substance cannot be regarded as inherently biodegradable.

Description of key information

OECD 302B, Zahn-Wellens Test: 8.2 % degradation after 28 days - not inherently biodegradable  

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Additional information

The biodegradation potential of Fe(Na)HBED was investigated according to OECD Guideline 302 B (Chojnacka, 2010). Activated sludge was used as inoculum and mixed with the test substance and mineral medium in 2 parallels. Further flasks were the procedure control (with the reference substance sodium benzoate), the inoculum blanks (each in 2 parallels) and one toxicity control (containing mineral medium, test substance, reference substance and inoculum). The suspended solid concentration was 0.3 g ss/L in each flask. The mixtures were agitated and aerated at 20 - 25 °C in the dark for a period of 28 days. The biodegradation process is monitored by determination of dissolved total organic carbon (DOC) with a spectrophotometer in filtered samples taken in daily intervals. The ratio of eliminated DOC, corrected for blank after each time interval, to the initial DOC value is expressed as the % biodegradation at the sampling time. The reference item attained 98 % degradation already after 14 days incubation, thereby fulfilling the validity criteria of the applied guideline, concluding that more or equal to 70 % degradation should have been occurred after 14 days. The test substance showed no toxic effects towards the used bacteria, since the toxicity control attained 55 % degradation after 28 days. The DOC content of the blank was below 10 mg/L at the start of the experiment. The test substance attained 3.2 % degradation after 14 days and 8.2 % degradation after 28 days, respectively. The test substance cannot be regarded as inherently biodegradable.