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Ecotoxicological information

Toxicity to microorganisms

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Administrative data

Endpoint:
activated sludge respiration inhibition testing
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The study was conducted according to O.E.C.D. Test Guideline No. 209 with GLP compliance.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1989
Report Date:
2009

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
ISO 8192 (Water quality - Test for inhibition of oxygen consumption by activated sludge for carbonaceous and ammonium oxidation)
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Type:
Constituent
Type:
Constituent
Details on test material:
As per IUCLID5 Sections 1.1. -1.4.

Sampling and analysis

Analytical monitoring:
no

Test solutions

Details on test solutions:
Direct weightings of the test substance were made to achieve the final concentrations of: 1000, 1800, 3200,5600 and 10000 mg/L.

Test organisms

Test organisms (species):
activated sludge of a predominantly industrial sewage
Details on inoculum:
Sludge from a laboratory scale sewage treatment plant was settled and the supernatant was decanted. After centrifuging (20 min at 4000 rpm and 20°C) the supernatant was decanted. Then approximately 1 g of the wet sludge was dried in order to calculate the amount of sludge to achieve a concentration of activated sludge of 6 g/L (dry weight) suspended solids. The dry sludge was resuspended in a defined synthetic medium for exposure.
- the calculated amount of sludge was first dissolved in synthetic medium and than filled up to a defined end volume with deionised water

Study design

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
3 h
Remarks on exposure duration:
with aeration
Post exposure observation period:
None.

Test conditions

Hardness:
No data
Test temperature:
20 ± 2°C
pH:
7 ± 0.2
Dissolved oxygen:
Permanent aeration
Salinity:
No data
Nominal and measured concentrations:
1.0, 1.8, 3.2, 5.6 and 10 gm/L nominal
Details on test conditions:
Exposure was conducted in 300 mL Erlenmeyer flasks with 6.0 gm/L dry weight activated sludge and aeration. Following three hours of contact the contents of the Erlenemeyer flasks were transfered to BOD bottles and the oxygen content measured with O2-meter redox electrode. .
Reference substance (positive control):
yes
Remarks:
3,5-Dichlorophenol

Results and discussion

Effect concentrations
Duration:
3 h
Dose descriptor:
EC50
Effect conc.:
4 593 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Details on results:
The inhibition of sludge respiration by BPA-Tars was dose-dependent and reached 87% inhibition relative to the control at the high nominal dose level of 10 gm/L. The positive control 3,5-dichlorophenol caused a 75% inhibition of sludge respiration.
Results with reference substance (positive control):
3,5-Dichlorophenol induced a 75% reduction in the sludge respiration rate at 20 mg/L.
Reported statistics and error estimates:
No data

Applicant's summary and conclusion

Validity criteria fulfilled:
not specified
Conclusions:
The estimated EC50 value of 4.54 gm/L for 2-Acetone polymer with phenol (BPA-Tars) suggests that BPA-Tars has little or no potential to inhibit the respiration of activated sludge. Therefore, BPA-Tars will be effectively removed by STPs.
Executive summary:

2 -Acetone polymer with phenol (BPA-Tars) was assessed for the ability to inhibit the biological activity of activated sewage sludge by an O.E.C.D. Test Guideline No. 209 study conducted with GLP compliance. The estimated EC50 value of 4.54 gm/L for BPA-Tars suggests that BPA-Tars has little or no potential to inhibit the respiration of activated sludge. Therefore, BPA-Tars will be effectively removed by STPs and not inhibit the removal of other waste streams.