N,N'-methylenebis[methacrylamide]

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:

1999-09-23 to 1999-10-21

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1999

Report date:

1999

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)

Version / remarks:

adopted 17 July, 1992

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.4-D (Determination of the "Ready" Biodegradability - Manometric Respirometry Test)

Version / remarks:

adopted 29 December, 1992

Deviations:

no

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

N,N'-methylenebis[methacrylamide]

EC Number:

219-102-3

EC Name:

N,N'-methylenebis[methacrylamide]

Cas Number:

2359-15-1

Molecular formula:

C9H14N2O2

IUPAC Name:

N,N'-methylenebis(2-methylacrylamide)

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): Activated sludge from the aeration tank of a municipal biological waste water treatment plant, not adapted, not pre-conditioned. The activated sludge was used immediately after sampling from the treatment plant without adaptation.
- Storage conditions: none
- Preparation of inoculum for exposure: Prior to the test the sludge was washed twice with tap water.
- Concentration of sludge: 30 mg/L

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

100 mg/L

Based on:

DOC

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation 1

Parameter followed for biodegradation estimation:

O2 consumption

Remarks:

O2 consumption was determined compared to the theoretical O2 demand

Parameter followed for biodegradation estimation 2

Parameter followed for biodegradation estimation:

DOC removal

Details on study design:

TEST CONDITIONS
- Composition of medium: see Table 1
- Test temperature: 22 ±
- pH: 7.4 ± 0.2
- pH adjusted: yes with NaOH or H2SO4
- Suspended solids concentration: 30 mg/L

TEST SYSTEM
- Culturing apparatus: The test vessels were agitated on an orbital shaker (100 r.p.m.) for a maximum test period of 28 days.
- Number of culture flasks/concentration: 2
- Measuring equipment: O2 uptake was measured by gas chromatography. Dissolved organic carbon (DOC) was determined in duplicate with a Shimadzu 5050 TOO-Analyzer using the NPOC-mode. For each determination 3 single injections were performed. The chemical O2 demand (COD), as a measure of the amount of O2 from potassium chromate that reacts with the oxidizable test substance, was determined using the Spectroquant COD Cell Test (E. MERCK, Darmstadt, Germany).

SAMPLING
- Sampling frequency: Samples were taken on day 0, 1, 4, 8, 12, 14, 18, 21, 25, and 28.


CONTROL AND BLANK SYSTEM
- Inoculum blank: lnoculum blank containing inoculum and test mediummeasured in two replicates
- Abiotic sterile control: not conducted
- Toxicity control: not conducted


STATISTICAL METHODS:
The percentage biodegradation was calculated from the BOD determinations and the ThOD or COD using the following equation: D = BOD/ThOD x 100 or D = BOD/COD x 100
D is the degradation at time t in %
ThOD is the theoretical O2 demand of the test substance in mg calculated from the elemental composition of the test substance (Cc,Hh,Clcl,Nn,Nana,Oo,Pp,Ss) according to: ThOD = 16(2c + 0.5(h-cl-3n) + 3s + 2.5p + 0.5na - o) mg/mg / Molecular weight
or, in case where nitrification of the nitrogen is assumed, according to: ThOD = 16(2c + 0.5(h - cl) + 2.5n + 3s + 2.5p + 0.5na - o) mg/mg / Molecular weight
BOD = a -bm/Co x V = mg O2 uptake by test substance - mg O2 uptake by blank / mg test substance in vessel
a is the mean O2 uptake of the two test units at time of determination in mg/L
bm is the mean O2 uptake of the mean of two inoculum blanks at time of determination in mg/L
C0 is the initial nominal concentration of the test substance in mg/L
V is the total volume of the test suspension in L
The mean percentage biodegradation of the test article rounded to the nearest full percent was specifically calculated at the end of the test and at the end of the 10-d window. The ultimate biodegradation was calculated from the DOC determinations as follows:
DT = [1- CT-C(B)T/ Co - C(B)o] x 100
DT is the degradation at the end of test in %
CT is the mean DOC value of the test unit at the end of the test in mg/L
C(B)T is the mean DOC value of the inoculum blank at the end of the test in mg/L
C(B)0 is the mean initial DOC value of the inoculum blank in mg/L
C0 is the mean initial DOC value in the test unit in mg/L

Reference substance

Reference substance:

benzoic acid, sodium salt

Results and discussion

% Degradation

% Degradation 1

Key result

Parameter:

% degradation (O2 consumption)

Value:

1.3

Sampling time:

8 d

Remarks on result:

other: Two replicates no standard deviation was measured

% Degradation 2

Key result

Parameter:

% degradation (O2 consumption)

Value:

1.6

Sampling time:

12 d

Remarks on result:

other: Two replicates no standard deviation was measured

% Degradation 3

Key result

Parameter:

% degradation (O2 consumption)

Value:

17.4

Sampling time:

28 d

Remarks on result:

other: Two replicates no standard deviation was measured

BOD5 / COD results

Results with reference substance:

The degradation in precent of sodium benzoate was 69.8 % after 8 days, 76.8 % after 12 days and 87.5 % after 28 days.

Any other information on results incl. tables

Table 2: O2 uptake of the test units, the inoculum blank and the corresponding degradation data

	Inoculum + blank	Test unit No. 1 containing test material			Test unit No. 2 containing test material
Time (days)	Total O2 uptake in test sample (mg)	Total O2 uptake in test sample (mg)	BOD (mgO2/mg Substance)	Degradation (%)	Total O2 uptake in test sample (mg)	BOD (mgO2/mg Substance)	Degradation (%)	Mean degradation of 1 +2 in (%)
0	0.00	0.00	0.00	0.0	0.00	0.00	0.0	0.0
1	-0.11	1.23	0.03	1.4	0.46	0.01	0.6	1.0
4	4.18	4.76	0.01	0.6	5.40	0.03	1.2	0.9
8	4.54	5.50	0.02	1.0	6.22	0.04	1.7	1.3
12	9.49	10.73	0.03	1.3	11.38	0.05	1.9	1.6
14	6.67	8.29	0.04	1.6	9.11	0.06	2.5	2.1
18	7.89	8.98	0.03	1.1	10.25	0.06	2.4	1.8
21	9.53	11.03	0.04	1.5	10.51	0.02	1.0	1.3
25	10.92	16.77	0.15	5.9	17.21	0.16	6.4	6.2
28	10.72	25.52	0.37	15.0	30.21	0.49	19.8	17.4

Table 3: O2 uptake of the procedure control

	Inoculum + blank	Procedure control containing sodium bezoate
Time (days)	Total O2 uptake in test sample (mg)	Total O2 uptake in test sample (mg)	BOD (mgO2/mg Substance)	Degradation (%)
0	0.00	0.00	0.00	0.0
1	-0.11	2.56	0.07	4.0
4	4.18	40.10	0.90	53.9
8	4.54	51.03	1.16	69.8
12	9.49	60.64	1.28	76.8
14	6.67	62.09	1.39	83.2
18	7.89	64.27	1.41	84.7
21	9.53	65.81	1.41	84.5
25	10.92	67.79	1.42	85.4
28	10.72	68.99	1.46	87.5

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

In this study, the degradation of the test item was 17 % after 28 days. The substance is therefore considered to be not readily biodegradable under the conditions of the test.

Executive summary:

In the present study conducted according to OECD test guideline 301F (adopted 27 July, 1992) activated sludge from a waste water treatment plant was incubated with N,N’-methylenebis[methacrylamide] for 28 days under aerobic, static conditions. During the test the oxygen consumption and the DOC concentrations were determined. The degradation of N,N’-methylenebis[methacrylamide] was 17 % after 28 days, thus the substance did not pass the 10 days window and was not degraded during the study. N,N’-methylenebis[methacrylamide] is therefore considered to be not readily biodegradable under the conditions of the test.