Potassium dimethyl 5-sulphonatoisophthalate

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:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 D (Ready Biodegradability: Closed Bottle Test)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Potassium dimethyl 5-sulphonatoisophthalate

EC Number:

233-915-0

EC Name:

Potassium dimethyl 5-sulphonatoisophthalate

Cas Number:

10433-41-7

Molecular formula:

C10H10O7S.K

IUPAC Name:

potassium 3,5-bis(methoxycarbonyl)benzene-1-sulfonate

Test material form:

solid: particulate/powder

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source of test material: sponsor
- purity: 96.6%
- Solubility in water: 14 g/L

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: At room temperature in the dark

Study design

Inoculum or test system:

activated sludge (adaptation not specified)

Details on inoculum:

The inoculum was derived from the secondary eflluent of Shanghai Longhua Sewage Plant. The inoculum was pre-conditioned by aerating the secondary eflluent, without other treatment or addition, for 5-7 days at the test temperature of 20 ± 1°C. Control microbe counted at the range of 104-106 orgs/L.

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

2 mg/L

Based on:

test mat.

Details on study design:

lt was important that the bottles were thoroughly clean before use. First of all, add to the empty bottle 5-10 ml of a wash solution (e.g. 2.5 g iodine plus 12.5g potassium iodide per litre of 1 % w/v sulfuric acid) shaking well to coat the bottle walls. Leave to stand for 15 min, pour off the solution and rinse thoroughly with tap water and finally deionised water.
Strongly aerate mineral medium for at least 20 minutes and stand for 20 h at the test temperature. Determine the concentration of dissolved oxygen for control purposes.
Prepare parallel groups of BOD bottles for the determination of the test and reference substances in simultaneous experimental series.
Add fully-aerated mineral medium to BOD bottles so that they were one-third full, then add sufficient of the stock solutions of the test and reference substances to separate BOD bottles.

Reference substance

Reference substance:

laurylsulfonate

Results and discussion

% Degradation

% Degradation 1

Key result

Parameter:

% degradation (O2 consumption)

Value:

0.7

Sampling time:

7 d

% Degradation 2

Key result

Parameter:

% degradation (O2 consumption)

Value:

1.16

Sampling time:

14 d

% Degradation 3

Key result

Parameter:

% degradation (O2 consumption)

Value:

1.16

Sampling time:

21 d

% Degradation 4

Key result

Parameter:

% degradation (O2 consumption)

Value:

1.39

Sampling time:

28 d

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

Based on the ThOD of potassium dimethyl 5-sulphonatoisophthalate (1.08 mg O2/mg), the average percent degradation of potassium dimethyl 5-sulphonatoisophthalate on days 7, 14, 21 and 28 was 0.70%, 1.16%, 1.16% and 1.39%, respectively.

Executive summary:

The biodegradability of potassium dimethyl 5-sulphonatoisophthalate was determined using the Closed Bottle Test Method. In the closed bottle test, inoculated mineral medium was dosed with a known amount of test substance as the nominal sole source of organic carbon. Degradation was followed by the analysis of dissolved oxygen over a 28-day test period. The test contained an inoculum control group, a reference group, and a treatment group. Each group contained ten replicate test chambers. The inoculum control was used to measure the oxygen uptake of the inoculum and was not dosed with a carbon source. The reference chambers were dosed with sodium lauryl sulfate, a substance known to be biodegradable, at a nominal concentration of 2 mg/L. The treatment group test chambers were used to evaluate the test substance at a nominal concentration of 2 mg/L. Measurements of dissolved oxygen were performed on two chambers from the control, reference, and treatment groups on days 0, 7, 14, 21 and 28.
The results indicated that the inoculum was active by degrading the reference substance, sodium lauryl sulfate, within the acceptable range (ie 60% within 14 days). The percent biodegradation of potassium dimethyl 5-sulphonatoisophthalate was calculated as 0.70%, 1.16%, 1.16% and 1.39% on days 7, 14, 21 and 28.