2-(2-heptadec-8-enyl-2-imidazolin-1-yl)ethanol

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)

GLP compliance:

no

Specific details on test material used for the study:

- Name of test material (as cited in study report): TK 10648
- Physical state: yellow liquid
- Analytical purity: not reported
- Batch No.: EN 42441
- Storage condition of test material: room temperature

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Details on inoculum:

- Source of inoculum/activated sludge: Bacteria collected from activated sludge of the sewage treatment plant of CH-4106 Therwil
- Preparation of inoculum for exposure: The preparation was carried out according to the method described in the guideline

Duration of test (contact time):

28 d

Initial conc.:

10.7 mg/L

Based on:

test mat.

Initial conc.:

20.5 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

- Vessels: 2 Liter flasks (dark brown glass)
- Water: The test medium was prepared according to the method described in the guideline
- Temperature: 22 ± 2 °C
- Duration: 28 days
- Aeration: 25 mL/ min free of CO2
- Preparation of the test medium: 1200 mL of the mineral solution with the inoculum were aerated for 24 hours in the test vessel. In 300 mL mineral solution 0.5 ml Nonylphenol 10EO5PO (solution of 30 mg in 100 mL bidist. water) and 16.1 rsp. 30.8 mg of test substance were added and homogenized. This solution was given to the test vessel which was immediately connected to the CO2 traps.

Reference substance:

aniline

Key result

Parameter:

% degradation (CO2 evolution)

Value:

1

Sampling time:

28 d

Results with reference substance:

82% after 28 days

Interpretation of results:

under test conditions no biodegradation observed

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)

GLP compliance:

no

Specific details on test material used for the study:

- Physical state: liquid
- Analytical purity: uvcb substance consisting of 96.6 % imidazolins

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, adapted

Details on inoculum:

- Source of inoculum/activated sludge: activated sludge taken from the waste water sewage plant of the city of Mannheim, Germany
- Initial cell/biomass concentration: 30 mg/L dry weight
- Pretreatment: 20 mg test substance were added to activated sludge (150 mg/L dry weight). The preparation was stirred and aerated. After 2 and 4 weeks one third of the volume was replaced by a freshly prepared solution. The total adaption period was 6 weeks.

Duration of test (contact time):

38 d

Initial conc.:

5 mg/L

Based on:

TOC

Remarks:

corresponding to 6.4 mg/L test material

Initial conc.:

5 mg/L

Based on:

TOC

Remarks:

related to co substance aniline

Initial conc.:

10 mg/L

Based on:

TOC

Remarks:

corresponding to 13.3 mg/L test material

Initial conc.:

10 mg/L

Based on:

TOC

Remarks:

related to co substance aniline

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Composition of medium: test substance (5 and 10 mg/l TOC, corresponding to 6.4 and 13.3 mg/L test material), aniline (5 and 10 mg/L TOC)
- pH: 7.4
- Initial cell/biomass concentration: 30 mg/L dry weight

CONTROL AND BLANK SYSTEM
- Inoculum blank: yes
- Reference control: yes

Reference substance:

aniline

Parameter:

% degradation (CO2 evolution)

Value:

71

Sampling time:

38 d

Remarks on result:

other: 10 mg/L (TOC) test substance and aniline

Parameter:

% degradation (CO2 evolution)

Value:

107

Sampling time:

38 d

Remarks on result:

other: 5 mg/L (TOC) test substance and aniline

Results with reference substance:

Degree of biodegradation 83% ater 38 days

Reference 3

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Principles of method if other than guideline:

Degradation tests according to Warburg method with adapted and not adapted activated sludge

GLP compliance:

no

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

- Sludge concentration: 3150 mg/L

Details on study design:

TEST SYSTEM
- The oxygen consumption of the sludge within 12 hours after the addition of test substance was determined.

Details on results:

The test results indicate that up to a concentration of 500 mg/l the fermentation of the substance in waste water treatment plants is possible. The activity of the activated sludge was reduced at higher test concentrations. In a second the degradation of the substance by adapted activated sludge was recorded. The activated sludge was adapted to the substance within 10 days. The substance concentration was increased every other day during the adaption period. The degradation rate was measured in a BOD5 test. A degradation rate of 77 % was determined at a substance concentration of 200 - 250 mg.

Description of key information

The substance is not readily biodegradable but probably inherently biodegradable.

Additional information

The biodegradation potential of the substance in water was determined in a screening study according to OECD TG 301B (CO2 -Evolution Test) (BASF, 1989). In this study 10.7 and 20.5 mg/L test substance was inoculated with domestic activated sludge for 28 days under aerobic conditions. During the incubation period degradation was followed by determining the carbon dioxide produced. After the 28 -day incubation period 1% of the test substance was biodegraded. In this study the toxicity of the substance to microorganisms and the low water solubility was not taken into account. In a second study following OECD 301 B the biodegradability of the substance was tested in concentration of 6.4 and 13.7 mg/L using adapted activated sludge as inoculum (BASF, 2010). After an adaption period of 6 weeks the inoculum was added to a mixture of the test substance and aniline. After an incubation period of 38 days a biodegradation of 107 % based on CO2 evolution was determined. The result indicates that the test substance is biodegradable in presence of a ready biodegradable co-substrate. This assumption is supported by a BOD5 study conducted with activated sludge as inoculum. A degradation rate of 77 % was determined at a substance concentration of 200 -250 mg (BASF, 1963).