REAKTIV-ORANGE DYPR 1410

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:

16 December 1998 to 13 January 1999

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.4-E (Determination of the "Ready" Biodegradability - Closed Bottle Test)

Deviations:

no

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Details on inoculum:

Type: mixed population of aquatic microorganisms (activated sludge)
Origin: secondary effluent of a domestic sewage treatment plant
Date of collection: 11.12.1998
Pre-treatment: none

Duration of test (contact time):

28 d

Initial conc.:

4.8 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

The test substance is suspended in a mineral medium, inoculated with a mixed population of aquatic microorganisms and incubated for 28 days under aerobic conditions in the dark at 20 ±1°C. During this period, the biodegradation of the test substance is determined on the basis of the reduction of dissolved oxygen.

Test substance: Reaktiv-Orange DYPR 1410
Concentration of the stock solution: 1.0gl test substance
Remarks: none
Initial concentration: 4.8mg/l test substance

Reference substance
Name of reference substance: Aniline
Purity: at least 99.5%
Initial concentration: 2.0mg/l reference substance

Inoculum
Source of sewage effluent: secondary effluent of a domestic sewage treatment plant
Treatment given: separation of coarse particles by filtration
Concentration of effluents in reaction mixture: 5 ml/l
Preconditioning: aeration for 5 days

Study conditions
Duration: 28 days
Test temperature20 ± 1°C

Reference substance:

aniline

Test performance:

The test performed in accordance with the recommendations of the test method.

Parameter:

% degradation (O2 consumption)

Value:

1

Sampling time:

28 d

Details on results:

In parallel preparations with the reference substance aniline a degradation of 85 % was achieved within 14 days.

Previously a Modified OECD Screening Test has been carried out with the test substance. Further experiments showed that the DOC of the test substance decreases by adsorption. Therefore the Modified OECD Screening Test is an inappropriate test method.

Results with reference substance:

Dissolved oxygen of reference substance: (mg O2/l after x days)
Bottle No. 0 days Bottle No. 7 days Bottle No. 14 days Bottle No. 21 days Bottle No. 28 days
11 9.66 13 5.86 15 5.14 17 4.26 19 4.21
12 9.68 14 6.08 16 4.69 18 4.28 20 4.26
Mean 9.67 5.97 4.92 4.27 4.24

Reference substance
Test concentration: 2.0 mg/l
ThOD: 2409 mg/g
COD: --- mg/g DO depletion after n days [mg/l]
7d 14d 21d 28d
No.1: (mt0 – mtx) – (mb0 – mbx) 3.19 3.84 4.53 4.60
No.2: (mt0 – mtx) – (mb0 – mbx) 2.99 4.31 4.53 4.57
D1: % Degradation 66 80 94 95
D2: % Degradation 62 89 94 95
D, Mean 64 85 94 95

Oxygen measurement

 

Dissolved oxygen of blank inoculum: (mg O2/l after x days)

Bottle No.	0 days	Bottle No.	7 days	Bottle No.	14 days	Bottle No.	21 days	Bottle No.	28 days
1	9.68	3	9.02	5	9.01	7	8.81	9	8.89
2	9.66	4	9.09	6	8.96	8	8.78	10	8.75
Mean	9.67		9.06		8.99		8.80		8.82

 

Dissolved oxygen of test substance: (mg O2/l after x days)

Bottle No.	0 days	Bottle No.	7 days	Bottle No.	14 days	Bottle No.	21 days	Bottle No.	28 days
21	9.61	23	9.13	25	8.98	27	8.76	29	8.81
22	9.68	24	9.07	26	9.10	28	8.79	30	8.73
Mean	9.65		9.10		9.04		8.78		8.77

 

Dissolved oxygen of toxicity control: (mf O2/l after x days)

Bottle No.	0 days	Bottle No.	7 days	Bottle No.	14 days	Bottle No.	21 days	Bottle No.	28 days
31	9.63	33	6.06	35	5.00	37	4.68	39	4.21
32	9.63	34	6.16	36	5.10	38	4.43	40	4.39
Mean	9.63		6.11		5.05		4.56		4.30

 

Results – DO depletion: % Degradation

 

Test substance Test concentration: 4.8mg/l ThOD: 1241 mg/g COD: --- mg/g	DO depletion after n days [mg/l]
	7d	14d	21d	28d
No.1: (mt0 – mtx) – (mb0 – mbx)	0.00	0.00	0.00	0.00
No.2: (mt0 – mtx) – (mb0 – mbx)	0.00	0.00	0.02	0.10
D1: % Degradation	0	0	0	0
D2: % Degradation	0	0	0	2
D, Mean	0	0	0	1

 

 

* Toxicity control	DO depletion after n days [mg/l]
	7d	14d	21d	28d
No.1: (mt0 – mtx) – (mb0 – mbx)	2.96	3.95	4.08	4.57
No.2: (mt0 – mtx) – (mb0 – mbx)	2.86	3.85	4.33	4.39
D1: % Degradation	27	37	38	42
D2: % Degradation	27	36	40	41
D, Mean	27	37	39	42

Comments: * In the toxicity control 4.8 mg/l test substance and 2.0 mg/l reference substance were used. The ThOD values respectively COD values of these substances are shown in the table above.

Validity criteria fulfilled:

yes

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

Within the test period of 28 days, a degradation of 1 % was determined for Realktiv-Orange DYPR 1410.

Executive summary:

Study conducted to procedure: Biodegradability - Closed Bottle Test Method according to Council Directive 92/69 EEC, Method C.4-E, in compliance with GLP.

 

The test substance is suspended in a mineral medium, inoculated with a mixed population of aquatic microorganisms and incubated for 28 days under aerobic conditions in the dark at 20±1°C. During this period, the biodegradation of the test substanceisdetermined on the basis of the reduction of dissolved oxygen.

 

In parallel preparations with the reference substance aniline a degradation of 85 % was achieved within 14 days.

 

Previously a Modified OECD Screening Test has been carried out with the test substance. Further experiments showed that the DOC of the test substance decreases by adsorption. Therefore the Modified OECD Screening Test is an inappropriate test method.

 

Within the test period of 28 days, a degradation of 1 % was determined for Realktiv-Orange DYPR 1410.

 

Hence, Reaktiv-Orange DYPR 1410 is not readily biodegradable.

Description of key information

Within the test period of 28 days, a degradation of 1 % was determined for Reaktiv-Orange DYPR 1410. Hence, Reaktiv-Orange DYPR 1410 is not readily biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Type of water:

freshwater