Octanoic acid, compound with 2,2',2''-nitrilotriethanol (1:1)

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:

April 1996

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

As Octanoic acid, compound with 2,2',2''-nitrilotriethanol (1:1) is highly soluble in water, and is expected to readily dissociate into Triethanolamine and Octanoic acid in the aquatic environment, it is considered appropriate to read across from Octanoic acid and Triethanolamine. Triethanolamine experimental data is from a peer reviewed scientific journal.

Data source

Reference

Reference Type:

publication

Title:

Biodegradation of triethanolamine.

Author:

West RJ and Gonsior SJ

Year:

1996

Bibliographic source:

Environ Toxicol Chem 15(4): 472-480.

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

CO2 evolution test

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

2,2',2''-nitrilotriethanol

EC Number:

203-049-8

EC Name:

2,2',2''-nitrilotriethanol

Cas Number:

102-71-6

Molecular formula:

C6H15NO3

IUPAC Name:

2,2',2''-nitrilotriethanol

Test material form:

liquid

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

other: Mixed liquor activated sludge (secondary effluent)

Details on inoculum:

Mixed liquor activated sludge (secondary effluent) was collected from the West Bay County Wastewater Treatment Plant, Bay City, Michigan, on December 17, 1991. This facility represented a typical municipal activated sludge process treating a daily flow of between 3 and 4 million gallons of primarily municipal (.90% v/v) sewage. Influent BOD loadings averaged between 150 and 200 mg/L, with mixed liquor suspended solids (MLSS) maintained on the order of 1,500 mg/L. A consolidated mixed liquor sample was collected just prior to secondary clarification. The sample was aerated in the laboratory for approximately 22 h to provide for removal of residual dissolved organic substrates. The mixed liquor was used in its collected state and diluted to achieve desired MLSS levels in the experimental reaction mixtures.

Duration of test (contact time):

ca. 6 d

Initial test substance concentration

Initial conc.:

> 600 - < 5 700 µg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

‘Biodegradation of TEA was examined in a series of reaction mixtures containing combinations of 600 or 5,700 μg/L TEA and 164 or 818 mg/L MLSS in a minimal salts basal medium. Duplicate reactions containing each combination of test material and mixed liquor solids concentrations were prepared in 500-ml polypropylene Erlenmeyer flasks. Single biologically inhibited control reactions were prepared or each configuration to measure potential abiotic losses of TEA. These were prepared in a manner similar to the viable reactions, with the exception that formaldehyde was incorporated at a final concentration of 2.8% (w/v). All reactions were amended with [14C]TEA to yield approximately 0.7 μCi/ml reaction solution. The specific activity of the [14C]TEA was adjusted with concentrated aqueous TEA solution to yield the desired total concentrations of test material. The reaction flasks were sealed using rubber stoppers fitted with 16 x 150-mm glass tubular CO2 traps containing 4 ml of a 1 N KOH solution. These traps consisted of capped culture tubes with openings cut near the bottom to allow headspace gas contact with the trap solution as the reaction mixtures were agitated. The activated sludge reactions were incubated in darkness at 25°C, with agitation provided at 125 rpm on a gyratory shaker’.

Results and discussion

% Degradation

% Degradation 1

Parameter:

% degradation (test mat. analysis)

Value:

100

Sampling time:

5 d

Remarks on result:

other: Primary biodegradation of 5.7 mg/L (38.2 μmol/L) TEA in a test with 164 mg/l municipal activated sludge.

% Degradation 2

Parameter:

% degradation (test mat. analysis)

Value:

ca. 100

Sampling time:

1 d

Remarks on result:

other: Primary biodegradation of 0.6 mg/L (4.02 μmol/L) TEA in a test with 164 mg/l municipal activated sludge.

Any other information on results incl. tables

Summary of TEA primary biodegradation adn mineraliztion in various environmental matrices (West & Gonsior, 1996):

Activated sludge(mg/L MLSS)	TEA Concen. (μmol/L)	TEA concen. (mg/L)	Biodegradation rate constant (/d)	Biodegradationhalf-life (d)	Mineraliation rate constant (/d)	Mineralisation half-life (d)	CO2/ThCO2(%)
164	4.0	0.6	6.86	0.1	1.92	0.36	56 ± 10
164	38.2	5.7	1.36	0.51	1.04	0.67	54 ± 3
818	4.0	0.6	30	0.02	2.86	0.24	55 ± 1
818	38.2	5.7	6.7	0.01	1.69	0.41	52 ± 0

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

It can be concluded from the results of this experimetnal study that triethanolamine is readily biodegradable.

Executive summary:

As Octanoic acid, compound with 2,2',2''-nitrilotriethanol (1:1) is expected to readily dissociate into Triethanolamine and Octanoic acid in the aquatic environment, which is supported by its very high water solubility, it is considered appropriate to read across from Triethanolamine.

The biodegradability of Triethanolamine was assessed in a study conducted by West & Gonsior (1996), this study was assigned a reliability score of 2 in accordance with the criteria for assessing data quality set forth by Klimischet al.(1997) as study is well documented and meets generally accepted scientific procedures.

Biodegradability was assessed in CO2 evolution study using mixed liquor activated sludge in a series of reaction mixtures containing combinations of 600 or 5700 μg/L and 164 or 818 mg/L mixed liquor suspended solids. Measurements were achieved by used radiolabelled Triethanolamine. Under the conditions of this study, Triethanolamine was found to readily biodegradable.