Findings – biodegradability – SESAMULS® OW

 FINDINGS

In the following tables, the IC values (given in mg/L) which were measured in the samples of the front scrubber flasks are stated.

Day

Apparatus blank 1

Apparatus blank 2

Control 1

Control 2

0

0.74

1.20

1.28

1.80

2

2.70

4.08

10.24

9.09

4

4.14

5.18

21.03

17.16

7

4.69

6.07

35.74

29.69

9

5.79

7.64

42.17

37.43

11

6.33

8.34

43.62

41.19

14

7.24

11.36

51.94

50.40

18

10.24

13.27

59.40

57.75

23

12.48

17.61

65.40

66.07

29

16.60

22.49

75.91

76.79

Table 3.1-a IC Values in mg/L Apparatus Blanks, Controls, front scrubber

Day

Positive Control 1

Positive Control 2

Test 1

Test 2

Abiotic Control

Toxicity Control

0

1.42

1.00

1.05

1.36

1.26

0.83

2

7.51

11.91

9.46

15.80

3.61

8.33

4

55.54

109.72

27.06

33.41

5.33

108.10

7

193.95

251.25

63.47

73.15

5.08

305.03

9

264.64

278.75

82.66

112.59

6.02

383.22

11

270.29

282.51

99.58

130.46

5.20

404.29

14

289.95

288.15

129.74

167.64

6.74

451.31

18

318.81

322.09

165.64

205.29

8.03

486.72

23

335.71

338.78

211.05

236.45

9.69

545.05

29

347.17

353.45

270.74

290.66

13.81

586.64

Table 3.1-b IC Values in mg/L Positive Control, Test Flasks, front scrubber

In the following tables, the IC values which were measured in the samples of the back scrubber flasks are stated.

Day

Apparatus blank 1

Apparatus blank 2

Control 1

Control 2

0

0.86

1.88

0.72

1.29

29

10.06

12.28

3.22

4.31

IC Values in mg/L Controls, Apparatus Blanks, back scrubber

Day

Positive Control 1

Positive Control 2

Test 1

Test 2

Abiotic Control

Toxicity Control

0

1.19

0.73

1.42

1.45

1.76

1.26

29

5.29

3.2

3.61

5.94

9.35

3.27

IC Values in mg/L Positive Control, Test Flasks, back scrubber

Net IC

For each flask, the IC value which was measured at the start of the test (d = 0) was subtracted from all following measurements. The net IC was calculated using this corrected measurement value and subtracting the mean IC value of the apparatus blanks sampling date.

The net IC values are presented in the following table.

Day

Control 1

Control 2

Positive Control 1

Positive Control 2

Test 1

Test 2

Abiotic Control

Toxicity Contro l

0

1.3

1.8

1.4

1.0

1.1

1.4

1.3

0.8

2

7.8

6.7

5.1

9.5

7.0

13.4

1.2

5.9

4

17.3

13.5

51.9

106.0

23.4

29.7

1.6

104.4

7

31.3

25.3

189.5

246.8

59.1

68.7

0.7

300.6

9

36.4

31.7

258.9

273.0

76.9

106.8

0.3

377.5

11

37.3

34.8

263.9

276.1

93.2

124.1

-1.2

397.9

14

43.6

42.1

281.6

279.8

121.4

159.3

-1.6

443.0

18

48.6

47.0

308.0

311.3

154.9

194.5

-2.8

475.9

23

51.3

52.0

321.6

324.7

197.0

222.4

-4.4

531.0

29

57.3

58.2

328.6

334.9

252.2

272.1

-4.8

568.1

Net IC-values in mg/L front scrubber flasks

Day

Control 1

Control 2

Positive Control 1

Positive Control 2

Test 1

Test 2

Abiotic Control

Toxicity Control

0

0.7

1.3

1.2

0.7

1.4

1.5

1.8

1.3

29

-6.6

-5.5

-4.5

-6.6

-6.2

3.9

-0.5

-6.5

Net IC-values in mg/L back scrubber flasks

Negative values occur, when the apparatus blank was higher than the respective treatment. As the measured values in these blanks as well as in the abiotic control are very low, measurement uncertainties lead to negative degradation values in the abiotic control.

 

In the following table, the pH at the end of the test (before addition of HCl) is given:

Day

Control 1

Control 2

Positive Control 1

Positive Control 2

Test 1

Test 2

Abiotic Control

Toxicity Control

28

7.4

7.4

7.2

7.2

7.4

7.4

6.8

7.2

pH Test flasks on day 28

Equations

Emitted Carbon in mg/L

Emitted Carbon in mg/L test solution at time t is calculated using the following equation:

emittC emitted carbon in mg/L test solution
IC (t) inorganic carbon in mg/L NaOH at time t
IC(0)  inorganic carbon in mg/L NaOH at the start of the test
VolNaOH (t) remaining volume NaOH in Lin thescrubber at time t (Volume at t=0(here:0.1L) – ∑ (all sample volumes up to time t))
VolTestVessel test vessel volume in L (here:1.5)

 

Calculation of emitted carbon is necessary for the assessment of validity. The value obtained with this equation is multiplied with 3.667 (44/12) in order to obtain emitted CO2.

Degradation in %
The percentage biodegradation in the test flasks was calculated from:

 

Degradation in positive control and toxicity flasks was calculated analogously. Abiotic degradation was calculated from:

Calculation Results

Emitted Carbon in mg/L

In the following table, the calculated emitted carbon is presented.

Day

Control 1

Control 2

Positive Control 1

Positive Control 2

Test 1

Test 2

Abiotic Control

Toxicity Control

2

0.43

0.32

0.24

0.56

0.40

0.79

0.00

0.34

4

1.05

0.76

3.29

6.86

1.46

1.85

0.02

6.77

7

1.94

1.52

12.17

15.90

3.75

4.36

-0.04

19.39

9

2.25

1.91

16.48

17.41

4.86

6.75

-0.06

24.11

11

2.28

2.09

16.63

17.43

5.84

7.77

-0.15

25.15

14

2.65

2.52

17.56

17.47

7.54

9.90

-0.18

27.71

18

2.93

2.80

19.01

19.24

9.54

11.98

-0.25

29.46

23

3.07

3.08

19.64

19.85

12.02

13.56

-0.35

32.52

29

2.92

2.98

19.47

19.77

14.73

16.07

-0.51

33.90

Emitted carbon in mg/L

Degradation Values

In the following table the percentage biodegradation is presented:

Day

Positive Control 1

Positive Control 2

Positive Control Mean

Test 1

Test 2

Mean

Abiotic Control

Toxicity Control

2

0.7

0.9

0.1

0.1

2.1

1.1

0.0

0.1

4

12.0

29.9

20.9

2.8

4.7

3.7

0.1

14.8

7

52.3

71.0

61.7

10.2

13.0

11.6

0.2

44.6

9

72.2

76.8

74.5

14.0

23.2

18.6

0.3

55.6

11

72.4

76.4

74.4

18.4

27.7

23.1

0.8

58.0

14

75.0

74.6

74.8

24.9

36.3

30.6

0.9

63.5

18

80.9

82.1

81.5

33.6

45.2

39.4

1.2

67.2

23

83.0

84.1

83.6

45.0

52.0

48.5

1.7

74.4

29

82.8

84.3

63.6

59.3

65.2

62.3

2.5

78.2

Degradation values in %

Degradation Graph