complex reaction mass of Chinese gum rosin post reacted with acrylic acid

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP, guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1999

Report date:

1999

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)

GLP compliance:

yes (incl. QA statement)

Test material

Reference

Name:

Unnamed

Type:

Constituent

Details on test material:

Sponsors identification: ARAKAWA KE-604
Description: pale yellow blocks
Batch No.: R61132
Purity: no data

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Sampling date: 6 JuIy 1998
- Source of inoculum: Sewage sludge from the aeration stage of the Severn Trent Water Plc sewage treatment plant at Belper, Derbyshire, UK, which treats predominantly domestic sewage.

- Preparation of inoculum for exposure: A sample of the activated sewage sludge was washed three times by settlement and resuspension in culture medium to remove any excessive amounts of dissolved organic carbon (DOC) that may have been present. A subsample of the washed sewage sludge was then removed and the suspended solids concentration determined.

- Storage conditions: The sample of activated sewage sludge was maintained on continuous aeration upon receipt
- Concentration of sludge: 30 mg suspended solids (ss)/I.

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

17.1 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Composition of culture medium: The culture medium used in this study was that recommended in the OECD Guidelines.
- Test samples: The test material was prepared by a direct dispersion in culture medium. 40.2 mg of the test substance was dispersed in approximately 200 ml of culture medium and subjected to ultrasonication for approximalely 30 minutes prior to dispersal in inoculated culture medium. The volume was adjusted to 3 litres to give a final concentration of 13.4 mg/l, equivalent to 10 mg carbon/l.
- Solubilising agent: no
- Test temperature: 21±1 C,
- Suspended solids concentration: 30 mg/l
- Continuous darkness: yes


TEST SYSTEM
- Culturing apparatus: 5 litre glass culture vessels each containing 3 litres of solution
- Number of culture flasks/concentration: 2
- Method used to create CO2 free conditions: The C02-free air was produced by sparging compressed alt‘ through carbosorb (sodalime) granules.
- Details of trap for CO2 and volatile organics if used: The CO2 produced by degradation was collected in two 500 ml Dreschel botties containing 350 ml of 0.05 M NaOH. The CO2 absorbing solutions were prepared using purified de-gassed water.


SAMPLING
- Sampling frequency: samples taken on days 0, 2, 3, 6, 8, 10, 14, 16, 20, 22, 24, 27, 28 and 29 were analysed for CO2 immediately
- Sampling method:
- Sample storage before analysis: The samples taken an day 1 were stored deep frozen at -20C prior to analysis. The samples taken on days 12 and 18 were also stored deep frozen at -20° C. However, these samples were not analysed for CO2 as the resuits obtained from previous and subsequent analyses.
- Sample Analysis: The samples were analysed for CO2 using an lonics 1 5558 TOC analyser and a Dohrmann DCI 90 TOC analyser.

Reference substance

Reference substance:

benzoic acid, sodium salt

Results and discussion

% Degradation

Parameter:

% degradation (CO2 evolution)

Value:

ca. 25

Sampling time:

28 d

BOD5 / COD results

Results with reference substance:

76 % degradation after 28 days
Standard test concentration: 17.1 mg/l (10 mg C/l)

Any other information on results incl. tables

The toxicity control attained 43% degradation after 28 days thereby confirming that the test material was not toxic to the sewage treatment micro-organisms used in the study

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

other: not readily biodegradable

Executive summary:

The test material only attained 25 % degradation after 28 days and therefore cannot be considered to be readily biodegradable.