Fatty acids, C18-unsatd., compds. with triethanolamine

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:

02.march 1995 - 30.march 1995

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1995

Report date:

1995

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Fatty acids, C18 unsatd., reaction products with triethanolamine

EC Number:

938-513-5

Cas Number:

1187872-27-0

IUPAC Name:

Fatty acids, C18 unsatd., reaction products with triethanolamine

Test material form:

liquid: viscous

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

Species/Origin: Aerobic activated sludge, micro organisms from a domestic waste water treatment plant was supplied from Frankfurt am Main-Sindlingen, Germany.
Conditioning: The aerobic activated sludge used for this study was washed by centrifugation and the supernatant liquid phase was decanted. The solid material was re-suspended in tap water and centrifuged again. This procedure was done three times. An aliquot of the final sludge suspension was weighed, dried and the ratio of wet sludge to its dry weight was determined. Based on this ratio, calculated aliquots of washed sludge suspension, corresponding to 26 mg dry material per litre were mixed with test water and aerated overnight. This suspension was used for the experiment.

Duration of test (contact time):

28 d

Initial test substance concentration

Initial test substance concentration 1

Initial conc.:

21.5 mg/L

Based on:

test mat.

Initial test substance concentration 2

Initial conc.:

22 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

The purpose of this study was to determine the ready biodegradability of the test item . The test item was exposed to aerobic activated sludge from the aeration tank of a domestic waste water treatment plant for 28 days. The biodegradation was followed by the CO2 evolution during exposure. The CO2 was trapped in washing flask containing Ba(OH)2.The quantitave determination of CO2 by titration. As a reference item sodium benzoate was tested simultaneously under the same conditions as the test item, and functioned as a procedure control.
This type of study is recognized by the international test guidelines and should provide a rational basis to assess the ready biodegradation properties of the test item when incubated with aerobic activated sludge.
Test Units
Type and Size: Two test flasks(A,B) containing a volume of approximately 5L each
Principle: The test flasks were incubated at 22°C * 1°C. The gassing was carried out by CO2-free-air. Ba(OH)2 was used for trapping the produced carbon dioxide. The calculation of the biological degradation was estimated as ration of generated carbon amount from CO2 to total carbon amount in material to be tested.

Preparation of Test Flasks:The amounts of test item and reference item were directly weighed into the test flasks. No emulsifiers or solvents were used.

Incubation: The closed test flasks were incubated in a climatised room under continuous stirring. The consumption of oxygen was determined by measuring the change of pressure in the flasks. Evolved carbon dioxide was absorbed in an aqueous solution (45%) of potassium hydroxide.
Test Duration: 28 days
Measurement of Oxygen: The change of pressure in the test flasks was measured by means of a manometric method (BSB/BOD-Sensor-System, Aqualytic Dortmund, Germany) each day.
Temperature: Temperature was measured each working day in the climatised room.
pH-Value: pH-values were measured in control, procedure control and a separately prepared test flask with test item at test start (to prevent loss of test item in the test flasks) and in all flasks at the end of the test using a pH-electrode WTW pH 340i.

Reference substance

Reference substance:

benzoic acid, sodium salt

Results and discussion

% Degradation

Parameter:

% degradation (CO2 evolution)

Value:

67

Sampling time:

28 d

Remarks on result:

other: readily biodegradable

Details on results:

The adaptation phase (10% CO2-evolution is reached) took 4 days. The CO2-evolution after adaptationreached in 10-days-window 67%.

Conclusion:
The degradation rate of test item reach 60% within the 10-day window or after 28 days. Therefore, the test item is considered to be readily biodegradable.

BOD5 / COD results

Results with reference substance:

Biodegradation of Reference Item Sodium Benzoate
Percentage Biodegradation: The reference item sodium benzoate was sufficiently degraded to 71.3% after 14 days and to 73.3% after
28 days of incubation.
Conclusion: The percentage biodegradation of the reference item confirms the suitability of the used aerobic activated sludge inoculum.

Any other information on results incl. tables

  

 

 

 

 

 

 

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

Degradation of test item was 67% after 28 days.
Therefore, test item is considered to be readily biodegradable.

Executive summary:

Title:	Test item: Ready Biodegradability in a CO2 -Evolution Test
Guidelines:	-     Commission Regulation 440/2008/EC, Method C.4 -C of: CO2 Evolution (Modified Sturm Test) (EEC Publication No. L 383 A, 1992) -     OECD Guideline for Testing of Chemicals No. 301 B: "Ready Biodegradability: CO2 Evolution "Modified Sturm Test", adopted 17 July 1992
Material and Methods:	Emulsogen TO
Test Species:	Aerobic activated sludge (microorganisms from a domestic waste­water treatment plant) was supplied by the sewage treatment plant of Frankfurt am Main-Sindlingen, Germany.
Test Design:	The test item Emulsogen TO was investigated for its ready biodegradability in a CO2 Evolution test over a period of 28 days. The biodegradation was followed by the CO2 -evolution during exposure. As a reference item sodium benzoate was tested simultaneously under the same conditions as the test item, and functioned as a procedure control.
Endpoints:	Degradation rate of test item calculated as ratio of carbon amount of the CO2 and the total carbon amount in the test item after 28 days of incubation.
Test Item Loading Rate (initial concentration in medium C0):	22 mg/l, 21.5 mg/l
Reference Item:	Sodium Benzoate
Reference Item Loading Rate:	20 mg/l
Test Conditions:	22°C ± 1°C, darkness
Results:
Biodegradation of Sodium Benzoate:	The reference item sodium benzoate was sufficiently degraded to 71.3% after 14 days and to 73.3% after 28 days of incubation, thus confirming the suitability of the aerobic activated sludge inoculum used.
Biodegradation of the Toxicity Control:	According to the test guidelines, the test item can be assumed to be inhibitory to the aerobic activated sludge microorganisms because degradation was 67% within 14 days.

This study is classified acceptable and satisfies the guideline requirements for ready biodegradability studies.