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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:
1 (reliable without restriction)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1998

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: crystalline
Details on test material:
A measured volume of inoculated mineral medium, containing a known cocncentration of test substance (100mg/L) as the nominal sole source of organic carbon, is stirred in a closed flask at a constant temperature (±1℃) for up to 28 days.

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge (adaptation not specified)
Duration of test (contact time):
32 d
Reference substance
Reference substance:
other: sodium benzoate

Results and discussion

% Degradationopen allclose all
Parameter:
% degradation (test mat. analysis)
Value:
77
Sampling time:
32 d
Parameter:
% degradation (test mat. analysis)
Value:
77
Sampling time:
28 d
Details on results:
oxygen uptakes, as read on the SAPROMAT meters, are corrected:
-by deducting the basic oxygen updates of sludge (flasks 1/7 and 1/8)
-proportionally to account for the small differences between actual and nominal concentrations of test and reference substances
Degradation of sodium benzoate exceeds 40% after 7 days and 65% after 14 days: the activity of the inoculum is thus verified and the test is considered as valid

Any other information on results incl. tables

    DAYS  5  7  15  21  28  32
 BOD sludge  1st flask B1  8.0 10.0  12.0  16.0  16.0  16.0 
 BOD sludge  2nd flaskB2  7.0 7.0  12.0   14.0  15.0  16.0
 BOD sludge  mean B  7.5 8.5  12.0   15.0 15.5  16.0 
 BOD test subst.  1st flask C1  104.2 148.9  199.5  235.2  246.2  247.2 
 BOD test subst  2nd flask C2  93.9  159.6  202.2 218.7   223.6  224.6
 BOD test subst  1st fl.corr C1 -B  96.7  140.4  187.5  220.2  230.7  231.2
 % degr  2nd fl.corr C2 -B 86.4   151.1  190.2  203.7  208.1  208.6
 % degr  1st flask D1  34  49  66  78  81  81
 % degr  2nd flask D2  30  53  67  72  73  73
 % degr  mead D  32  51  67  75  77  77

Applicant's summary and conclusion

Interpretation of results:
readily biodegradable
Conclusions:
camphor undergoes 77% biodegradation after 32 days (alos 77% after 28days) in the test conditions. Biodegradation starts on day 5 and reaches 67% at the end of the 10-day window (day 5to 15).
Thus, camphor should be regarded as readily biodegradable according to this test.
The curves obtained with the reference substance alone and with camphor+ reference show no toxic effect of camphor to the micro-organisms at the test concentration.