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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:
4 (not assignable)

Data source

Reference
Reference Type:
review article or handbook
Title:
Unnamed
Year:
2011

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other:
Principles of method if other than guideline:
biodegradation experiment in conical bottle with title comp. as sole carbon source; incubated
at pH ca. 6.5-7.1; analyzed by reverse phase HPLC and GC-MS;
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
purity:99.9%

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
other: acclimated activated sludge
Details on inoculum:
ABSTRACT
Acclimated activated sludge was examined for its ability to degrade mono-fluorophenols as the sole carbon
source in aerobic batch cultures. The acclimated activated sludge degraded fluorophenol efficiently. It
degraded 100 mg/l 3-fluoropheno and 4-fluorophenol in 16 h with, respectively, 99.85% and 99.91%
fluoride anion release and it degraded 50 mg/l 2-fluorophenol in 15 h with 99.26% fluoride anion release.
The aerobic biodegradability of the mono-fluorophenols decreased in the order: 4-fluorophenol > 3-
fluorophenol > 2-fluorophenol, resulting mainly from a different octanol/water partition coefficient and
different steric parameter of the fluorophenols. The mechanism study revealed that the initial step in the
aerobic biodegradation of mono-fluorophenols by the activated sludge was their transformation to fluorocatechol.
Following transformation of the fluorophenol to fluorocatechol, ring cleavage by catechol 1, 2-
dioxygenases proceeded via an ortho-cleavage pathway, then defluorination occurred.
Duration of test (contact time):
ca. 3.5 - 7 h
Initial test substance concentration
Initial conc.:
50 - 125 mg/L
Based on:
test mat.
Details on study design:
Temperature [°C] 25

Results and discussion

% Degradationopen allclose all
Value:
100
Sampling time:
3.5 h
Remarks on result:
other: Concentration:50mg/l
Value:
100
Sampling time:
5 h
Remarks on result:
other: concentration:75 mg/l
Value:
100
Sampling time:
7 h
Remarks on result:
other: Concentration:125 mg/l

Applicant's summary and conclusion

Interpretation of results:
readily biodegradable
Conclusions:
In the present study, 4-fluorophenol (50 to 125 mg/L) was found to be readily biodegradable in 3.5 to 7 hours, (in inoculum under aerobic conditions) indicating its readily biodegradable nature.
Executive summary:

In the present study, 4-fluorophenol (50 to 125 mg/L) was found to be readily biodegradable in 3.5 to 7 hours, (in inoculum under aerobic conditions) indicating its readily biodegradable nature.