Solsperse 22000-Wirksubstanz

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:

June 15, 2000 - July 13, 2000

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2000

Report date:

2000

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

Species/Origin: Aerobic activated sludge, micro organisms from a domestic sewage purification plant was supplied by the sewage plant Frankfurt am Main, Kriftel, Germany.
Conditioning: The aerobic activated sludge used for this study : After a settling period of approx. 30 minutes the supernatant liquid phase was decanted and crude particles were removed by a sieve. After resuspension with mineral medium, settling down and decantation, the sludge was concentrated by centrifugation. 10 g concentrated sludge was then resuspended in 1 liter of mineral medium. Before resuspension, an aliquot of concentrated sludge was used for dry weight determination.

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

80 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

The purpose of this study was to determine the ready biodegradability of the test item . The test item was exposed to aerobic activated sludge from the aeration tank of a domestic waste water treatment plant for 28 days. The biodegradation was followed by the oxygen uptake of the microorganisms during exposure. As a reference item aniline was tested simultaneously under the same conditions as the test item, and functioned as a procedure control. Evolving carbon dioxide was absorbed by potassium hydroxide placed in rubber containers inside the sampling bottles. Due to the reduction in the amount of oxygen the pressure in the bottles sank.This change was detected and stored by the manometers. After the data transfer to the control display, the BOD (Biochemical Oxygen Demand) was determined.
This type of study is recognized by the international test guidelines and should provide a rational basis to assess the ready biodegradation properties of the test item when incubated with aerobic activated sludge.
Test Units
Type and Size: Manometric Test System with test flasks containing a volume of approximately 500 mL.
Apparatus: BSB/BOD-Sensor-System, Aqualytic Dortmund, Germany
Principle: The test flasks were incubated at 22°C * 1°C. The pressure decrease in the reaction vessels was measured over complete experimental phase of 28 days using the BSB/BOD-Sensor-System, Aqualytic Dortmund, Germany. The test flasks were closed gas-tight by a measuring head. Potassium hydroxide solution (45%) was used for trapping the produced carbon dioxide. The amount of O2 consumed by the activated sludge was calculated from the decrease of pressure in the reaction vessel.

Preparation of Test Flasks:The amounts of test item and reference item were directly weighed into the test flasks. No emulsifiers or solvents were used.

Incubation: The closed test flasks were incubated in a climatised room under continuous stirring. The consumption of oxygen was determined by measuring the change of pressure in the flasks. Evolved carbon dioxide was absorbed in an aqueous solution (45%) of potassium hydroxide.
Test Duration: 28 days
Measurement of Oxygen: The change of pressure in the test flasks was measured by means of a manometric method (BSB/BOD-Sensor-System, Aqualytic Dortmund, Germany) each day.
Temperature: Temperature was measured each working day in the climatised room.
pH-Value: pH-values were measured in control, procedure control and a separately prepared test flask with test item at test start (to prevent loss of test item in the test flasks) and in all flasks at the end of the test using a pH-electrode WTW pH 340i.

Reference substance

Reference substance:

aniline

Results and discussion

% Degradation

Parameter:

% degradation (O2 consumption)

Value:

< 60

Sampling time:

28 d

Remarks on result:

other: not readily biodegradable

Details on results:

The test item contains nitrogen;therefore the evaluation of biodegradation has to be
based ThODNH4 and ThODNO3. The criterion for ready biodegradability under the conditions of a manometric
respirometry test is the 10-day window, describing the period between reaching at least 10% degradation
and 60% degradation. This period should not exceed 10 days.

The mean biodegradation of the test item at test end after 28 days was < 60%% (ThODNH4, ThODNO3).

Conclusion:
The degradation rate of test item did not
reach 60% within the 10-day window or after 28 days. Therefore, the test item is considered to be not readily biodegradable.


Biodegradation in the Toxicity Control

Percentage Biodegradation: In the toxicity control containing both, the test item and the reference item aniline, 62% (ThODNH4) biodegradation was noted within 8 days and 92% (ThODNH4) biodegradation after 28 days of incubation. According to the test guidelines, the test item can be assumed to be not inhibitory to the aerobic activated sludge microorganisms because degradation was <60% within 14 days.
Conclusion: According to the test guidelines the test item can be assumed to be not inhibitory to the aerobic activated sludge microorganisms because degradation was <60% within 14 days.

BOD5 / COD results

Results with reference substance:

Biodegradation of Reference Item aniline
Percentage Biodegradation: The reference item aniline was sufficiently degraded to 62% after 8 days and to 92% after 28 days of incubation.
Conclusion: The percentage biodegradation of the reference item confirms the suitability of the used aerobic activated sludge inoculum.

Any other information on results incl. tables

Table 2 Cumulative Biochemical Oxygen Demand (mg O₂/L) / Incubation temperature

Time    [days]	flask no.							Temperature [°C]
	8	9	3	4	5	10	11
1	2.8	0	4.2	2.8	1.4	0	5.6	22.8
4	5.6	4.2	9.9	7.0	80.3	1.4	90.1	22.8
5	7.0	5.6	11.3	8.5	88.8	1.4	101	22.3
6	5.6	5.6	9.9	8.5	91.6	0	107	22.8
8	7.0	7.0	11.3	9.9	100	0	130	22.8
10	8.5	7.0	12.7	11.3	123	0	152	22.3
11	9.9	8.5	11.3	11.3	127	0	163	21.9
12	9.9	8.5	12.7	12.7	131	0	163	22.1
13	11.3	9.9	11.3	11.3	134	1.4	169	21.1
14	9.9	9.9	15.5	12.7	137	0	169	22.6
15	11.3	11.3	12.7	11.3	138	0	175	22.1
18	12.7	11.3	16.9	14.1	141	0	175	21.2
19	14.1	11.3	16.9	14.1	142	0	180	21.4
20	12.7	11.3	14.1	12.7	142	0	175	22.4
21	12.7	11.3	15.5	12.7	142	0	180	21.9
22	14.1	12.7	15.5	14.1	144	1.4	186	22.3
25	15.5	14.1	18.3	15.5	148	1.4	186	22.8
26	14.1	14.1	16.9	14.1	147	1.4	186	22.1
27	15.5	14.1	18.3	15.5	148	1.4	192	22.3
28	15.5	14.1	16.9	14.1	147	1.4	186	22.1

flask 8 +9: Test substance (ThOD_NH4=150 mg/L)

flask 3 +4: Inoculum control

flask 5: Procedure control (aniline; ThOD_NH4=144 mg/L)

flask 10: Abiotic control (ThOD_NH4=136 mg/L)

flask 11: Toxicity control (aniline+test substance; ThOD_NH4=294 mg/L)

Table 3 Biodegradation of the test substance and aniline [%]

The percentage values given were corrected against the O2 uptake of the inoculum controls

Time  [days]             flask no.  8  9  5  11  1  0  -2  -1  0  4  -2  -3  50  28  5  -2  -3  55  31  6  -2  -2  57  33  8  -2  -2  62  40  10  -2  -3  77  48  11  -1  -2  81  52  12  -2  -3  82  51  13  0  -3  85  54  14  -3  -3  85  53  15  0  0  88  55  18  -2  -3  88  54  19  -1  -3  88  56  20  0  -2  90  55  21  -1  -2  89  56  22  0  -1  90  58  25  -1  -2  91  57  26  -1  -1  91  58  27  -1  -2  91  60  28  0  -1  92  58

     

flasks 8 +9: Test substance

flask 5: Procedure control (aniline)

flask 11: Toxicity control

     

Table 4 pH-values

Time [days]                      flask no.  8  9  3  4  5  10  11  1  7.5  7.5  7.5  7.4  7.5  7.5  7.5  28  7.5  7.5  7.5  7.5  7.4  7.5  7.4

flasks 8 +9: Test substance

flasks 3 +4: Inoculum control

flask 5: Procedure control (aniline)

flask 10: Abiotic control

flask 11: Toxicity control

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

Degradation of test item was <60% after 28 days.
Therefore, test item is considered to be not readily biodegradable.

Executive summary:

Title:	Test item: Ready Biodegradability in a Manometric Respirometry Test
Guidelines:	-     Commission Regulation 440/2008/EC, Method C.4-D of: Manometric Respirometry Test (EEC Publication No. L 142/496, May 2008) -     OECD Guideline for Testing of Chemicals No. 301 F: "Ready Biodegradability: Manometric Respirometry Test", adopted
Material and Methods:
Test Item:	Solsperse 22000
Test Species:	Aerobic activated sludge (microorganisms from a domestic waste­water treatment plant) was supplied by the domestic sewage purification plant of Kriftel, Germany.
Test Design:	The test item Solsperse 22000 was investigated for its ready biodegradability in a manometric respirometry test over a period of 28 days. The biodegradation was followed by the oxygen uptake of the microorganisms during exposure. As a reference item aniline was tested simultaneously under the same conditions as the test item, and functioned as a procedure control.
Endpoints:	Degradation rate of test item calculated by the oxygen consumption of the aerobic activated sludge microorganisms after 28 days of incubation.
Test Item Loading Rate (initial concentration in medium C0):	80 mg/L corresponding to an oxygen demand of about 150 mg/L (ThODNH4)
Reference Item:	aniline
Reference Item Loading Rate:	60 mg/L corresponding to an oxygen demand of about 144 mg/L (ThODNH4)
Test Conditions:	22°C ± 1°C, darkness
Results:
Biodegradation of Solsperse 22000:	The test item contains nitrogen; therefore the evaluation of biodegradation has to be based ThODNH4and ThODNO3. The criterion for ready biodegradability under the conditions of a manometric respirometry test is the 10-day window, describing the period between reaching at least 10% degradation and 60% degradation. This period should not exceed 10 days. The mean biodegradation at test end after 28 days was 0% (ThODNH4, ThODNO3). Therefore,test item is considered to be not readily biodegradable based on ThODNH4/ ThODNO3.
Biodegradation of Aniline:	The reference item aniline was sufficiently degraded to 62% after 8 days and to 92% after 28 days of incubation, thus confirming the suitability of the aerobic activated sludge inoculum used.
Biodegradation of the Toxicity Control:	In the toxicity control containing both, the test item and the reference item aniline, 40% (ThODNH4) biodegradation was noted within 8 days and 58% (ThODNH4) biodegradation after 28 days of incubation . According to the test guidelines, the test item can be assumed to be not inhibitory to the aerobic activated sludge microorganisms because degradation was <60% within 14 days.

This study is classified acceptable and satisfies the guideline requirements for ready biodegradability studies.