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Environmental fate & pathways

Biodegradation in water: screening tests

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Reference
Endpoint:
biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
key study
Study period:
Oct 17, 1990 to Jan 10, 1991
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: study performed using international guidelines under GLPs using commercial material as test article and published.
Qualifier:
according to guideline
Guideline:
OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I))
Deviations:
no
GLP compliance:
yes
Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge (adaptation not specified)
Details on inoculum:
300 ml of basal culture medium to which innoculum added so that suspended solid reached 30 mg/L
Duration of test (contact time):
28 d
Initial conc.:
100 mg/L
Based on:
test mat.
Parameter followed for biodegradation estimation:
O2 consumption
Parameter followed for biodegradation estimation:
test mat. analysis
Details on study design:
Water + test substance; Sludge + test substance; Sludge + test substance; Sludge + test substance; Sludge + aniline; Control Blank.

Test substance = 100 mg/L. Aniline = 100 mg/L. Activated sludge = 30 mg/L. Temperature 25 +- 1 degree C. Duration 28 d. Measured BOD at 7, 14, 21 and 28 days after innoculation. After incubation, weighed samples and evaluated IR spectrum.
Reference substance:
aniline
Test performance:
Aniline was degraded 63, 81, 84 and 85% by days 7, 14, 21, and 28, respectively.
Key result
Parameter:
% degradation (O2 consumption)
Value:
0
Sampling time:
28 d
Key result
Parameter:
% degradation (test mat. analysis)
Value:
2
Sampling time:
28 d
Details on results:
Appearance of Test Media
Day 0 Water + test substance : Test substance not dissolved.
Day 0 Sludge + test substance: Test substance not dissolved.
Day 28 Water + test substance: Test substance remained insoluable.
Dau 28 Sludge + test substance: Test substance remained insoluable. No growth of sludge observed

% Biodegradation
Method Percentage biodegradation (%)
Test Vessel 1 Test Vessel 2 Test Vessel 3 Mean
BOD 1 0 0 0
Weight 6 0 1 2


Results with reference substance:
Aniline was degraded 63, 81, 84 and 85% by days 7, 14, 21, and 28, respectively. The control blank performed as expected. No degradation was seen in the water + test substance vessel.

Table 1. Calculation Table on the Degree of Biodegradation by BOD

Test No. 11893.  Duration of cultivation: 28 days

Vessel

No.

Day 7

Day 14

Day 21

Day 28

Mean

Degr.

(%)

BOD

(5)

Degr.

(%)

BOD

(5)

Degr.

(%)

BOD

(5)

Degr.

(%)

BOD

(5)

Degr.

(%)

1

58.0

63

74.9

81

79.2

87

81.2

85

 

2

0.8

-

1.4

-

2.9

-

4.1

-

 

4

0.8

0

1.2

0

2.5

0

4.2

1

0

5

0.4

0

0.8

0

1.9

0

3.2

0

 

6

0.0

0

0.0

0

1.4

0

2.9

0

 

3

0.0

-

0.0

-

0.0

-

0.0

-

 

 

Degr. : Degree of biodegradation

Vessel No. 1: Sludge + Aniline

Vessel No. 2: Control blank (B)

Vessels No. 4,5,6: Sludge + Test substance

Vessel No. 3: Water + Test Substance

 

Test substance added: 30 mg

Degr. = (BOD-B)/(TOD) × 100%

 

TOD of test substance: 14.7 mg

C14H4Br10+ 15 O2 --> 14 CO2+ 2 H2O + 10 Br

15 O2/ C14H4Br10 = 479.98/971.23 = 0.49

TOD = 30.0 × 0.49 = 14.7 mg

 

TOD of aniline: 90.3 mg

C6H7N + 8.75 O2 -- > 6 CO2+ 3.5 H2O + NO2

8.75 O2/ C6H7N = 279.99/93.13 = 3.01

TOD = 30.0 × 3.01 = 90.3 mg

 

Table 2. Calculation Table for Percentage Biodegradation

Test No. 11893

Vessel No.

Sample description

A

(mg)

D

(mg)

E

(%)

F

(%)

3

Water + Test Substance

28.7

29.8

 

 

4

Sludge + Test Substance

32.0

28.2

6

 

5

Sludge + Test Substance

34.5

30.8

0

2

6

Sludge + Test Substance

33.2

29.4

1

 

2

Control blank

4.9

 

 

 

 

Amount of test substance added: 30 mg

A:   Amount of residue (mg)

B:   Ratio of portion used for analysis: Water (300/300), Sludge (300/300)

C:   Recovery rat: Water (96.2%), Sludge (96.2%)

D:   Residual amount of test substance (mg)

           Water: D=A/B/(C/100)

            Sludge: D=(A-A(Control blank))/B/(C/100)

E:   Percentage biodegradation (%)

           E=(D(Water+ Test Substance)-D(Sludge + Test Substance))/D(Water + Test Substance) × 100

F:   Average percentage biodegradation (%)

Table 3. Calculation Table for the Recovery Rate

Test No. 11893

Sample description

A

(mg)

C

(mg)

D

(%)

E

(%)

Water + Test Substance 1

29.1

29.1

97.0

 

Water + Test Substance 2

28.6

28.6

95.3

96.2

Sludge + Test Substance 1

37.2

28.5

95.0

 

Sludge + Test Substance 2

37.9

29.2

97.3

96.2

Control blank

8.7

 

 

 

Amount of test substance added: 30 mg

A:   Amount of residue (mg)
B:   Ratio of portion used for analysis (300/300)

C:   Recovery amount (mg)

           Water: C=A/B

           Sludge: C=(A-A(Control blank))/B

D:   Recovery rate (%)

           D=C/30 mg × 100

E:   Average recovery rate (%)

DBDPEthane was not readily biodegradable by activated sewage sludge over a 28-day period when tested under Japanese MITI/OECD Ready Biodegradability 301C Modified MITI guidelines.  IR spectra indicated the test substance was unchanged.

Validity criteria fulfilled:
yes
Interpretation of results:
under test conditions no biodegradation observed
Conclusions:
DBDPEthane was not readily biodegradable by activated sewage sludge over a 28-day period when tested under Japanese MITI/OECD Ready Biodegradability 301C Modified MITI guidelines.  IR spectra indicated the test substance was unchanged.
Executive summary:

DBDPEthane was not readily biodegradable by activated sewage sludge over a 28-day period when tested under Japanese MITI/OECD Ready Biodegradability 301C Modified MITI guidelines.  IR spectra indicated the test substance was unchanged.

Description of key information

Ready Biodegradation (Kurume Labs, 1991), OECD 301C

EBP was not readily biodegradable by activated sewage sludge over a 28-day period when tested under Japanese MITI/OECD Ready Biodegradability 301C Modified MITI guidelines.  IR spectra indicated the test substance was unchanged.

Key value for chemical safety assessment

Biodegradation in water:
not biodegradable
Type of water:
other: activated sewage

Additional information