Acetic acid, oxo-, sodium salt, reaction products with ethylenediamine and phenol, iron sodium salts

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2009-12-18 to 2010-03-15

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 A (Ready Biodegradability: DOC Die Away Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.4-A (Determination of the "Ready" Biodegradability - Dissolved Organic Carbon (DOC) Die-Away Test)

Version / remarks:

2008

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 835.3110 (Ready Biodegradability)

Deviations:

no

Qualifier:

according to guideline

Guideline:

ISO 7827 (Evaluation in an Aqueous Medium of the "Ultimate" Aerobic Biodegradability of Organic Compounds - Method by Analysis of Dissolved Organic Carbon (DOC))

Deviations:

no

GLP compliance:

yes (incl. QA statement)

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): wastewater treatment plant of Mannheim, Germany.
- Laboratory culture: The inoculum was collected on 04 January 2010 from the aeration tank of the plant and aerated in the laboratory until use.
- Method of cultivation: A suitable aliquot of the activated sludge suspension was sieved by a finely woven mesh with a mesh size about 1 mm. The activated sludge suspension was pre-aerated for about 24 hours at a temperature of 22 +/- 2 degree C.
- Preparation of inoculum for exposure: On day of exposure the sludge was allowed to settle. After settling the supernatant was discarded and the remaining sludge suspension was filled up with tap water. The sludge of the suspension was adjusted to a concentration of 6.0 g/L dry weight.
- Concentration of sludge: Aliquots of 5 mL were added to the test vessels to obtain a sludge concentration of 30 mg/L dry substance.

Duration of test (contact time):

28 d

Details on study design:

TEST CONDITIONS
- Test temperature: 22 +/- 2 degree C
- pH: 7.4 +/- 2
- pH adjusted: yes
- Aeration of dilution water: yes

Reference substance:

aniline

Preliminary study:

The test guideline recommends a test concentration of the test substance of 10 - 40 mg/L Dissolved Organic Carbon (DOC). A test concentration of 20 mg/L DOC was used. The selected test concentration of 20 mg DOC/L corresponds to approximately 62 mg/L Acetic acid, oxo-, sodium salt.
It is anticipated that the selected test concentration causes no toxic effects to the microorganisms. The selected test concentration was tested in an additional inhibition control test assay and no toxic effects to the microorganisms were observed.

Key result

Parameter:

% degradation (DOC removal)

Value:

>= 10 - <= 20

Sampling time:

28 d

Details on results:

See below at "Any other information on results incl. tables"

Results with reference substance:

See below at "Any other information on results incl. tables"

ACCOUNT OF TEST RESULTS

Test substance: Acetic acid.oxo-.sodium salt

Stock Solution, initial weight: 1233.7 mg/L

Dissolved Organic Carbon (DOC): 403 mg/L

DOC conc. at the test (nominal): 20 mg/L

Reference substance: aniline

Stock Solution, initial weight: 400.5 mg/L

Theoretical Organic Carbon (ThOC): 310 mg/L (calculated by initial weight)

DOC conc. at the test (nominal): 20 mg/L

 

Sample		BC1	BC2	RS	IH	PC	AC	TS1	TS2
Test substance concentration [mg/L] |		-	-	-	61.7	61.7	61.7	61.7	61.7
Inoculum conc. [mg/L dry matter]		30	30	30	30	-	30	30	30
Demineralized water [mL/vessel]		982	982	917	867	936	931	932	932
Mineral	solution A	10	10	10	10	10	10	10	10
medium	solution B	1	1	1	1	1	1	1	1
[mL/L]	solution C	1	1	1	1	1	1	1	1
	solution D	1	1	1	1	1	1	1	1
Stock Solution; test substance [mL]		-	-	-	50	50	50	50	50
Stock Solution; reference subst.[mL]		-	-	65	65	-	-	-	-
Mercury chloride sol.| [mL/vessel]		-	-	-	-	1	1	-	-
pH values before; after correction		7.8	7.8	7.8	7.7	7.7	7.7	7.7	7.8
		7.4	7.4	7.4	7.4	7.4	7.4	7.4	7.4
Inoculum (6 g/L) [mL/vessel]		5	5	5	5	-	5	5	5
Total test volume [mL]		1000	1000	1000	1000	1000	1000	1000	1000

 

Legend: BC = blank control; RS = reference substance; IH = inhibition control; PC = abiotic control; AC = adsorption control; TS = test substance

Removal of Dissolved Organic Carbon (DOC) [%]:

Test duration [days]	RS	IH	PC	AC	TS1	TS2	TS mv
0	0	0	0	0	0	0	0
1	-1	0	-5	3	-1	1	0
3	10	12	-3	7	7	5	6
7	96	53	1	7	9	10	10
10	92	52	-2		8	5	7
14	91	52	3		7	5	6
17	95	55	-3		12	12	12
21	93	54	1		8	6	7
24	95	57	6		13	13	13
27	98	59	3		17	16	17
28	97	57	4		11	10	11

Legend: BC = blank control; RS = reference substance; IH = inhibition control; PC = abiotic control; TS = test substance, AC = adsorption control; mv = mean value

Validity criteria fulfilled:

yes

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

FeNaEDDHA was not readily biodegradable under the conditions of a DOC Die-Away test.

Executive summary:

The DOC Die-Away Test is a batch test method to determine the ultimate aerobic biodegradability of a test substance in water. Mixtures of the test substance FeNaEDDHA, a defined inorganic medium and a non pre-adapted inoculum (e.g. activated sludge or effluent from a municipal wastewater treatment plant) are incubated and aerated at a temperature of 22 +/- 2 degree C for up to 28 days regularly. Samples are taken at regular intervals to determine the Dissolved Organic Carbon concentration (DOC).

Biodegradation degree: 10-20 % after an exposure period of 28 days (mean value of two test assays)

Removal of Dissolved Organic Carbon (DOC): Acetic acid, oxo-, sodium salt was poorly biodegradable under the conditions of this test.

Based on co-incubation with anilin, it could be demonstrated that the test concentration used (20 mg/L DOC) was not toxic (inhibitory effect) on the sewage treatment bacteria flora.

Evaluation in accordance to criteria of the OECD Test Guideline: FeNaEDDHA was not readily biodegradable under the conditions of this test.

Description of key information

not readily biodegradable: 10-20% in 28 days (OECD 301B) 

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Type of water:

freshwater

Additional information

A guideline study accomplished according to OECD guideline 301B showed 10-20 % degradation based on DOC removal after an incubation time of 28 days (BASF 2010). Thus, FeNaEDDHA is not readily biodegradable under the given test conditions.