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Environmental fate & pathways

Biodegradation in water: screening tests

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Administrative data

Endpoint:
biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: The method described in the publication was conducted in compliance with an OECD guideline.
Cross-referenceopen allclose all
Reason / purpose:
reference to same study
Reason / purpose:
reference to other study

Data source

Reference
Reference Type:
publication
Title:
Biodegradation and Bioaccumulation Data of Existing Chemicals based on the CSCL Japan
Author:
Anonymous
Year:
1992
Bibliographic source:
Japan Chemical Industry Ecology-Toxicology & Information Center

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I))
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Benzylamine

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
other: sludge samplings from different sewage plants, rivers, bays and a lake
Details on inoculum:
- Source of inoculum/activated sludge:
Sludge sampling was made at the following 10 places in Japan: Fukogawa city sewage plant, Fukashiba industry sewage plant, Nakahama city sewage plant, Ochiai city sewage plant, Kitakami river, Shinano river, Yoshino river, Lake Biwa, Hiroshima bay, Dookai bay.
Sampling method: (1) City sewage: returned sludge of sewage plants were collected; (2) Rivers, lakes and sea: Surface water and surface soil which is in contact with atmosphere were collected.

- Culture:
5 L of the filtrate of the supernatant of an activated sludge in the present use was mixed with 500 mL of the filtrate of the supernatant of a newly collected sludge respectively and the mixture was cultured at pH 7 under the sufficient aeration (using prefiltered open air). About 30 minutes after ceasing the aeration to the sludge mixture, supernatant corresponding to about 1/3 of the whole volume was removed. Then the equal volume of dechlorination water was added to the remaining portion and aerated again, followed by addition of synthetic sewage, concentration of that portion was to be 0.1% (w/v). This procedure was repeated once every day. The culturing was carried out at 25 +/- 2°C. (Synthetic sewage: Glucose, peptone and monopotassium phosphate were dissolved in dechlorination water. Each conentration of them was to be 5% (w/v) and the solution was adjusted to pH 7 with sodium hydroxide.)

- Preparation of inoculum for exposure:
(1) Measurement of concentration of suspended solid: Method in accordance with japanses Industrial standards (JIS) K 0102-1986-14.1.
(2) Preparation of basal culture medium: Each 3 mL of solutions A, B, C and D which are described in JIS K 0102-1986-21, were made up to 1000 mL with purified water and then pH of this solution was adjusted to 7.
(3) Reference substance: Aniline was used as reference substance.

- Preparation of test solutions:
water + test substance (300 mL purified water + 30 mg of test substance), sludge + test substance (300 mL basal culture medium + 30 mg or of test substance), sludge + anailine (300 mL basal culture medium + 30 mg anailine), control blank (300 mL basal culture medium).
Activated sludge was added to each test vessel containing basal culture medium, in such a way that concentration of suspended soil reached to 30 mg/L.

- Instrument and condition of cultivation:
closed system oxygen measuring apparatus; vessel: 300 mL of volume; absorbent for carbon dioxide: soda lime No.1 (extra pure reagent);
test solution was stirred by magnetic stirrer;
cultivating temperature: 25 +/- 2°C
cultivating duration: 14 days
Duration of test (contact time):
14 d
Initial test substance concentration
Initial conc.:
100 mg/L
Based on:
test mat.
Parameter followed for biodegradation estimation
Parameter followed for biodegradation estimation:
test mat. analysis
Remarks:
and determination of total organic carbon
Details on study design:
TEST CONDITIONS
- Test temperature: 25 +/- 2°C
- pH: 7
- pH adjusted: yes

TEST SYSTEM
- Culturing apparatus: Closed system oxygen consumption measuring apparatus (Coulometer: Ohkura Electric Co., Ltd.)

CONTROL AND BLANK SYSTEM
- Inoculum blank: Vessel containing 300 mL of basal culture medium into which no test substance or control substance was added.
- Toxicity control: Aniline was used as a reference substance.
Reference substance
Reference substance:
aniline

Results and discussion

Preliminary study:
No data
Test performance:
After termination of cultivation, total organic carbon and test substance in test solutions were determined. The pH of the test solutions (water + test substance and sludge + test substance) were measured. The mean degree of biodegradation as calculated from BOD was in the range of 52-75% and 62-91% ( calculated from theoretical oxygen demand).
% Degradationopen allclose all
Parameter:
% degradation (test mat. analysis)
Value:
52 - 75
Sampling time:
14 d
Parameter:
% degradation (test mat. analysis)
Value:
62 - 91
Sampling time:
14 d
Remarks on result:
other: calculated from theoretical oxygen demand
Details on results:
The mean degree of biodegradation as calculated from BOD was in the range of 52-75% and 62-91% ( calculated from theoretical oxygen demand).

BOD5 / COD results

Results with reference substance:
As not stated otherwise, the percentage of biodegradation of anailine calculated by BOD value were beyond 40% and 60% at day 7 and 14 after initiation of the test, respectively.

Any other information on results incl. tables

No other information.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Interpretation of results:
readily biodegradable
Conclusions:
The mean degree of biodegradation as calculated from BOD was in the range of 52-75% and 62-91% (calculated from theoretical oxygen demand) and, thus, benzylamine is considered readily biodegradable.
Executive summary:

The study was conducted according to OECD 301C, Ready Biodegradabilty: Modified MITI Test (I).

Sludge sampling was made at 10 different places in Japan from sewage plants, rivers, bays and a lake. Activated sludge (30 mg/L) was incubated with benzylamine (final concentration of 100 mg/L) for 14 days at 25°C in a closed system oxygen measuring apparatus.

After termination of cultivation, total organic carbon and test substance in test solutions were determined. The pH of the test solutions (water + test substance and sludge + test substance) were measured.

The mean degree of biodegradation as calculated from BOD was in the range of 52-75% and 62-91% (calculated from theoretical oxygen demand) and, thus, benzylamine is considered readily biodegradable.