4-(2-hydroxyethyl)piperazin-1-ylethanesulphonic acid

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:

from 2000-11-23 to 2001-01-15

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 D (Ready Biodegradability: Closed Bottle Test)

Version / remarks:

1992

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: activated sludge, microorganisms from a domestic waste water treatment plant
- Origin: sewage plant Gross-Zimmern, Germany
- Method of cultivation: The 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 again centrifuged. This procedure was repeated twice. 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 4 g dry material per litre were mixed with test water and then aerated until use. Before use the sludge was filtered through cotton wool.

Duration of test (contact time):

28 d

Initial conc.:

4 mg/L

Based on:

ThOD/L

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of medium: according to guideline OECD 301 D (1992)
- Additional substrate: no
- Solubilising agent: no
- Test temperature: at room temperature
- pH: 7.6 (measured at the start of the test)
- pH adjusted: no
- Aeration of dilution water: yes
- Suspended solids concentration: 4 g/L
- Continuous darkness: yes

TEST SYSTEM
- Culturing apparatus: Karlsruher flasks of 250 mL volume with glass stoppers
- Number of culture flasks/concentration:
16 bottles containing the test item and inoculum
16 bottles containing the reference item Aniline and inoculum (procedure control)
16 bottles containing only inoculum (inoculum control)
10 bottles containing the test item, reference item aniline and inoculum (toxicity control)
- Measuring equipment: The oxygen concentrations were electrochemically measured in an airtight system with an 02-electrode (WTW Oxi 340, Wissenschaftlich Technische Werkstatten
- Test performed in closed vessels due to significant volatility of test substance: no
- Test performed in open system: yes

CONTROL AND BLANK SYSTEM
- Inoculum blank: yes
- Abiotic sterile control: yes
- Toxicity control: yes
- Positive control: yes

Reference substance:

aniline

Test performance:

The validity criteria were met.
The reference item aniline was sufficiently degraded to in the mean 84 % after 14 days, and to 93 % after 28 days of incubation, thus confirming the suitability of the used activated sludge inoculum.
In the toxicity control containing both, the test item and the reference item aniline, in the mean 36 % biodegradation was noted within 14 days and 46 % biodegradation after 28 days of incubation. Thus, the test item can be assumed to be not inhibitory on the activated sludge micro organisms.

Key result

Parameter:

% degradation (O2 consumption)

Value:

-2

Sampling time:

28 d

Details on results:

Under the test conditions the percentage biodegradation of the test material, based on ThODNH4, reached in the mean -2 % after 28 days of incubation. If the calculation of biodegradation is based on ThODNO3, percentage biodegradation reached in the mean -1 % after 28 days of incubation.

Results with reference substance:

The percentage degradation of the reference item aniline reached the level for ready biodegradability (> 60 % within 7 days). The reference item aniline was sufficiently degraded to in the mean 84 % after 14 days, and 93 % after 28 days of incubation.

Validity criteria fulfilled:

yes

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

The ready biodegradability of the test item was determined according to OECD 301 D (1992). Within the study period of 28 days, a degradation of < 0 % was determined for the test substance. Therefore, the test substance can be considered to be not ready biodegradable.

Executive summary:

The ready biodegradability of the test item was determined according to OECD 301 D (1992). The test item was investigated for its ready biodegradability in a Closed Bottle Test over a period of 28 days. The biodegradation was followed by the oxygen uptake of the micro-organisms during exposure. As a reference item aniline was tested simultaneously under the same conditions as the test item, and functioned as a procedure control. The reference item aniline was sufficiently degraded to in the mean 84 % after 14 days, and to 93 % after 28 days of incubation, thus confirming the suitability of the used activated sludge inoculum. In the toxicity control containing both, the test item and the reference item aniline, in the mean 36 % biodegradation was noted within 14 days and 46 % biodegradation after 28 days of incubation. Thus, the test item can be assumed to be not inhibitory on the activated sludge microorganisms. Under the test conditions the percentage biodegradation of the test substance based on ThODNH4, reached in the mean -2 % after 28 days of incubation. If the calculation of biodegradation is based on ThODNO3, percentage biodegradation reached in the mean -1 % after 28 days of incubation. Within the study period of 28 days, a degradation of < 0 % was determined for the test substance. Therefore, the test substance can be considered to be not ready biodegradable.

 

Description of key information

The ready biodegradability of the test item was determined according to OECD 301 D (1992) (reference 5.2.1-1). Within the study period of 28 days, a degradation of < 0 % was determined for the test substance. Therefore, the test substance can be considered to be not ready biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Additional information

The ready biodegradability of the test item was determined according to OECD 301 D (1992). The test item was investigated for its ready biodegradability in a Closed Bottle Test over a period of 28 days. The biodegradation was followed by the oxygen uptake of the micro-organisms during exposure. As a reference item aniline was tested simultaneously under the same conditions as the test item, and functioned as a procedure control. The reference item aniline was sufficiently degraded to in the mean 84 % after 14 days, and to 93 % after 28 days of incubation, thus confirming the suitability of the used activated sludge inoculum. In the toxicity control containing both, the test item and the reference item aniline, in the mean 36 % biodegradation was noted within 14 days and 46 % biodegradation after 28 days of incubation. Thus, the test item can be assumed to be not inhibitory on the activated sludge microorganisms. Under the test conditions the percentage biodegradation of the test substance based on ThODNH4, reached in the mean -2 % after 28 days of incubation. If the calculation of biodegradation is based on ThODNO3, percentage biodegradation reached in the mean -1 % after 28 days of incubation. Within the study period of 28 days, a degradation of < 0 % was determined for the test substance. Therefore, the test substance can be considered to be not ready biodegradable.