N,N-Diethylacrylamide

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 2013-08-23 to 2013-09-30

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I))

Version / remarks:

1992

GLP compliance:

yes

Specific details on test material used for the study:

Purity: 99.95%
Batch No.: DEAA-P

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge: 11 sites in Korea including 4 rivers, 3 domestic sewage treatment plants and 4 industrial wastewater treatment plants.
- Storage conditions: 25 ± 2 °C
-pH: 7 ± 1
- Preparation of inoculum for exposure: the samples were mixed together. After removing floating matter and coarse particle, mixture (inoculum) was adjusted to 7 ± 1, more than 5 mg/L of dissolved oxygen concentration.

Duration of test (contact time):

28 d

Initial conc.:

100 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of medium:
Solution A: K2HPO4 2.175g, KH2PO4 0.85g, Na2HPO4•12H2O 4.46g, NH4CI 0.17g
Solution B: MgSO4•7H2O 2.25g
Solution C: CaCI2 2.75g
Solution D: FeCI3•6H2O 0.025g
-Concentration of test item and reference item: 100 mg/L (w/v)
-Concentration of inoculum: 30 mg/L (w/v, dry weight of suspended solids)
-Temperature: 25±1°C
-Period: 28 days
-Condition: performed in the dark

MICROBIAL DEGRADATION
-Bottle 1 (abiotic control): deionized water + test item
-Bottle 2, 3, 4 (treatment): mineral medium + inoculum + test item
-Bottle 5 (activity control): mineral medium + inoculum + reference item
-Bottle 6 (inoculums blank): mineral medium + inoculum

Reference substance:

other: sodium benzoate

Key result

Parameter:

% degradation (O2 consumption)

Value:

1.6

Sampling time:

28 d

Details on results:

The BOD concentration at 28 days in test item were 25.3, 19.7 and 8.4 mg/L, respectively. The results indicated that the percentage mircrobial degradation of test item based on the theoretical oxygen demand (ThOD) was 1.6%.

The percentage microbial degradation of test item by HPLC was negative at 28 days. Recoveries of test item were 96.9% and 97.8% at abiotic control and treatment, respectively.

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

The test item could not be concluded to be readily degradable by microorganisms in the aquatic environment based on OECD pass level of biodegradability (60%).

Executive summary:

Microbial degradation of test item was performed for 28 days following the OECD 301C (1992).

 

The results are as follows:

 

1)      The percentage microbial degradation of reference item, observed by BOD meter was 85.9% after 7 days and 92.7% after 14 days based on the theoretical oxygen demand (ThOD NH4), thus confirming suitable of inoculums. It was within the acceptance range specified by OECD guidelines and the National Institute of Environmental Research.

 

2)      The percentage microbial degradation of test item observed by BOD meter based in the theoretical oxygen demand (THOD NH4) was 1.6% at 28 days.

 

3)      The percentage microbial degradation of test item analyzed by HLPC was negative at 28 days.

 

Therefore, the test item could not be concluded to be readily degradable by microorganisms in the aquatic environment based on OECD pass level of biodegradability (60%).

Description of key information

The percentage microbial degradation of test item was 1.6% at 28 days. Therefore, the test item could not be concluded to be readily degradable by microorganisms in the aquatic environment based on OECD pass level of biodegradability (60%).

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Type of water:

freshwater