Potassium hydrogen -5-amino-4-hydroxybenzene-1,3-disulphonate

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: inherent biodegradability

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Remarks:

according to OECD 302C, limited documentation

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1991

Report date:

1991

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 302 C (Inherent Biodegradability: Modified MITI Test (II))

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Potassium hydrogen -5-amino-4-hydroxybenzene-1,3-disulphonate

EC Number:

280-719-6

EC Name:

Potassium hydrogen -5-amino-4-hydroxybenzene-1,3-disulphonate

Cas Number:

83763-34-2

Molecular formula:

C6H7NO7S2.K

IUPAC Name:

potassium hydrogen -5-amino-4-hydroxybenzene-1,3-disulphonate

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge: a mixed population of activated sludge microorganisms; Severn Trent PLC Sewage Treatment Plant, Belper, Derbiyshire .
- Pretreatment: The activated sludge was maintained at a temperature of 21 ± 1°C . The sludge was washed and settled repeatedly using dilution water prior to use.
- Usage rate: Equivalent to 100 mg dry weight/L

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

30 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS

- Test temperature: 25 ± 1°C
- Aeration of dilution water: Continuous stirring
- Continuous darkness: yes


TEST SYSTEM

- Number of culture flasks/concentration: 1
- Method used to create aerobic conditions: Continuous stirring
- Measuring equipment: The oxygen consumption was measured by direct manometer reading



CONTROL AND BLANK SYSTEM

- Functional control: aniline, 100 mg/L

Reference substance

Reference substance:

aniline

Results and discussion

Test performance:

The test solutions were prepared in measuring flasks and given into brown glass bottles as incubation vessels (inoculum control, functional control) or were prepared directly in brown glass
bottles (test item, blank):
• 3 incubation vessels for the test item (P1, P2, P3)
• 2 incubation vessels for the functional control (R1, R2)
• 1 incubation vessel for the blank (B1)
• 2 incubation vessels for the inoculum control (C1, C2)

Separate replicates for the test item and blank were prepared for pH measurement at test start:
• 1 incubation vessel for the test item (PpH)
• 1 incubation vessel for the blank (BpH)

The test item was weighed out and was transferred directly into the brown glass bottles with 250 mL test medium (consisting of the appropriate volumes of mineral medium stock solutions, de-mineralised water and inoculum) for the test item replicates and with 250 mL demineralised water for the blank, respectively.

% Degradation

Key result

Parameter:

% degradation (O2 consumption)

Value:

>= 104 - <= 116

Sampling time:

28 d

Details on results:

The test substance attained between 104 and 116 % degradation within 28 days calculated from oxygen uptake (% COD) and so, therefore, can be considered as inherently biodegradable.

BOD5 / COD results

Results with reference substance:

Aniline attained 49 % biodegradation after 7 days and 67 % after 14 days thereby confirming the suitability of the inoculum and culture conditions. Total organic carbon analysis of the test media at day 0 and day 28 showed, that aniline attained 93 % within 28 days.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

inherently biodegradable

Conclusions:

Under our test conditions, the test item was inherently biodegradable within 28 days.

Executive summary:

The inherent biodegradability of the test item was determined in the Modified MITI Test (II) with non adapted activated sludge for a period of 28 days. The study was conducted according to OECD Guideline 302 C . The test item concentration selected as appropriate was 30 mg/L. The oxygen was depleted by respiration of bacteria and the degradation was measured by direct manometer reading.

The test substance attained between 104 and 116 % degradation within 28 days calculated from oxygen uptake (% COD) and so, therefore, can be considered as inherently biodegradable.

In order to check the activity of the test system Aniline was used as functional control. The functional control reached the pass level of > 65 % after 14 days. It came to a biodegradation rate of 93 % after 28 days.