CHE506 - Lab Report On Growth Study of Microorganisms in Bioreactor Using Different Strategy (L7) (2018) PDF

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UNIVERSITI TEKNOLOGI MARA FAKULTI KEJURUTERAAN KIMIA REACTION ENGINEERING LABORATORY (CHE506) NAME : NURLINA SYAHIIRAH BINTI MD TAHIR STUDENT NO : 2017632214 GROUP : EH2205I EXPERIMENT : GROWTH STUDY OF MICROORGANISM IN BIOREACTOR USING DIFFERENT STRATEGY DATE PERFORMED : 22nd OCTOBER 2018 SEMESTER ...

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UNIVERSITI TEKNOLOGI MARA FAKULTI KEJURUTERAAN KIMIA REACTION ENGINEERING LABORATORY (CHE506) NAME STUDENT NO GROUP EXPERIMENT DATE PERFORMED SEMESTER PROGRAMME / CODE SUBMIT TO No. 1 2 3 4 5 6 7 8 9 10 11 12 13

: NURLINA SYAHIIRAH BINTI MD TAHIR : 2017632214 : EH2205I : GROWTH STUDY OF MICROORGANISM IN BIOREACTOR USING DIFFERENT STRATEGY : 22nd OCTOBER 2018 :5 : CHEMICAL ENGINEERING / EH220 : MADAM SYAZANA MOHAMAD PAUDZI

Title Abstract/Summary Introduction Aims Theory Apparatus Methodology/Procedure Results Calculations Discussion Conclusion Recommendations Reference Appendix TOTAL MARKS

Allocated Marks (%)

Marks

5 5 5 5 5 10 10 10 20 10 5 5 5 100

Remarks: Checked by:

Rechecked by:

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Date:

Date:

1

TABLE OF CONTENT

1.0

ABSTRACT ................................................................................................................... 3

2.0

INTRODUCTION......................................................................................................... 4

3.0

OBJECTIVES ............................................................................................................... 5

4.0

THEORY ....................................................................................................................... 6

5.0

MATERIALS & APPARATUS ................................................................................... 8

6.0

METHODOLOGY ....................................................................................................... 9

7.0

RESULTS .................................................................................................................... 12

8.0

CALCULATIONS ...................................................................................................... 28

9.0

DISCUSSION .............................................................................................................. 29

10.0 CONCLUSION ........................................................................................................... 31 11.0 RECOMMENDATIONS............................................................................................ 32 12.0 REFERENCES ............................................................................................................ 33 13.0 APPENDIX .................................................................................................................. 34

LAB REPORT ON GROWTH STUDY OF MICROORGANISM IN BIOREACTOR USING DIFFERENT STRATEGY (L7)

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1.0

ABSTRACT

Oxygen is essential for all aerobic growth. The main objective of the experiment is to measure the volumetric mass transfer coefficient (kLa) of the stirred tank reactor with bubble aeration. The method used is static gassing out method. The volumetric mass transfer coefficient at aeration equals to 0.5 L/min, 1.0 L/min, 1.5 L/min, 2.0 L/min and 2.5 L/min are 0.0110 s-1, 0.0291 s-1, 0.0334 s-1, 0.0282 s-1 and 0.0282 s-1, respectively. The higher the aeration magnitude, the greater the value of the volumetric mass transfer coefficient The volumetric mass transfer coefficient at agitation equals to 200 rpm, 400 rpm, 600 rpm, 800 rpm and 1000 rpm are 0.0201 s-1, 0.0355 s-1, 0.0540 s-1, 0.0775 s-1 and 0.0824 s-1, respectively. The greater the agitation magnitude, the greater the value of the mass transfer coefficient. The volumetric mass transfer coefficient at temperature equals to 35°C, 40°C, 45°C, 50°C are 0.0332 s-1, 0.0356 s-1, 0.0386 s1

and 0.0407 s-1, respectively. The higher the temperature, the higher the magnitude of the

volumetric mass transfer coefficient. Comparing all three operating parameters, the most significant one is the agitation, followed by aeration and temperature, respectively.

LAB REPORT ON GROWTH STUDY OF MICROORGANISM IN BIOREACTOR USING DIFFERENT STRATEGY (L7)

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2.0

INTRODUCTION

Oxygen is essential for all aerobic growth. Most of the biochemical processes require oxygen in order to yield the output. Thus, maintaining appropriate concentration of dissolved oxygen, DO in the bioreactor is vital for the reactor efficiency. So that, the reaction can be initiate and the desired product can be yield. Thus, the rate of transfer of oxygen between the two phases, gaseous and the reaction liquid is investigated by determining the volumetric mass transfer coefficient kLa in a stirred tank with bubble aeration. The method used for the experiment is the gassing out method in the absence of bacteria or cell. Aeration, agitation and temperature are the three factors that affect the capability of a reactor’s oxygen mass transfer chosen for the experiment. The equipment used in the experiment is MINIFORS.

Figure 1 - The Phases of Bacteria Cell Growth Table 1 - Phases of Bacteria Cell Growth Phase I

The cell concentration shows a little increasing pattern. The cells are

Lag Phase

adjusting to their new environment, synthesizing enzymes and getting ready to begin reproducing.

Phase II

The rate of growth of the cell is proportional to the cell concentration.

Exponential Growth

At this phase, all the enzyme’s pathways for metabolizing the substrate are in place. Thus, the cells are dividing at maximum rate.

Phase III Stationary Phase Phase IV

The net growth rate is zero since the cells reached the minimum biological space. Decrease in live cell concentration.

Death Phase

LAB REPORT ON GROWTH STUDY OF MICROORGANISM IN BIOREACTOR USING DIFFERENT STRATEGY (L7)

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3.0

OBJECTIVES

The following are the objectives for the experiment: 1) To use the gassing out method for the experiment. 2) To determine the driving force, (C* - CL) of the stirred tank reactor with bubble aeration. 3) To measure the volumetric mass transfer coefficient (kLa) of the stirred tank reactor with bubble aeration. 4) To quantify the effects of operating variables on the provision of oxygen.

LAB REPORT ON GROWTH STUDY OF MICROORGANISM IN BIOREACTOR USING DIFFERENT STRATEGY (L7)

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4.0

THEORY

The gassing – out method is used in the experiment to determine the volumetric mass transfer coefficient, kLa in the MINIFORS (Stirred Tank Bioreactor) using water as the only simulating media. Nitrogen gas is used to gassing out the liquid so that the oxygen concentration of the solution is lowered. Thus, making the solution scrubbed free of oxygen. The increase in dissolved oxygen is monitored after the deoxygenated liquid is aerated and agitated. This method utilize the graphical technique to determine the experimental values of volumetric mass transfer coefficient, kLa. The oxygen transfer rate decreases as the driving force decreases. The oxygen trasnfer rate will be equal to the slope of tangent to the curve of values of dissolved oxygen concentration against time of aeration. (Organisms, 2018).

Dynamic Gassing Out Method Oxygen Transfer Rate (OTR) is the rate at which oxygen is transferred into solution. 𝐎𝐓𝐑 = 𝐤 𝐋 𝐀(𝐂 ∗ − 𝐂𝐋 ) Where, kL

= oxygen transfer coefficient (cm/h)

A

= gas – liquid interfacial area (cm2/cm3)

kLA

= Volumetric oxygen transfer coefficient (h-1)

C*

= Saturated dissolved oxygen concentration (mg/L)

CL

= Actual dissolved ocygen concentration in the broth (mg/L)

OTR

= oxygen transfer rate (mg O2 / L.h)

Oxygen Uptake Rate (OUR) is the rate at which bacteria or other microorganisms consume oxygen. 𝐎𝐔𝐑 = 𝐪𝐎𝟐 𝐗 Where, qO2

= specific rate of oxygen consumption (mmol O2/gdw.h)

X

= bacteria concentration (gdw/L)

gdw

= gram dry weigt of cells

LAB REPORT ON GROWTH STUDY OF MICROORGANISM IN BIOREACTOR USING DIFFERENT STRATEGY (L7)

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Substituting the OUR and OTR equation yield the following equation, 𝐝𝐂𝐋 = 𝐤 𝐋 𝐀(𝐂 ∗ − 𝐂𝐋 ) − 𝐪𝐎𝟐 𝐗 𝐝𝐭 𝐝𝐂𝐋 𝐝𝐭

+ qO2 X , the slope equal to -1/kLA.

𝐂𝐋

The plot of CL against

𝐝𝐂𝐋 + 𝐪𝐎𝟐 𝐗 𝐝𝐭 Figure 2 - CL against

𝐝𝐂𝐋 𝐝𝐭

+ 𝐪𝐎𝟐 𝐗

Static Gassing Out Method The increased in dissolved oxygen concentration is given by the following equation, 𝐝𝐂𝐋 = 𝐤 𝐋 𝐀(𝐂 ∗ − 𝐂𝐋 ) 𝐝𝐭 Integrating the equation yield to the following equation, ∫

𝐝𝐂𝐋 = ∫ 𝐤 𝐋 𝐀 𝐝𝐭 (𝐂 ∗ − 𝐂𝐋 )

𝐥𝐧(𝐂 ∗ − 𝐂𝐋 ) = 𝐤 𝐋 𝐀. 𝐭

𝐥𝐧(𝐂 ∗ − 𝐂𝐋 )

The plot of the ln (C* - CL) against time, the slope equals to -kLA.

𝐓𝐢𝐦𝐞 Figure 3 - ln (C* - CL) against time

LAB REPORT ON GROWTH STUDY OF MICROORGANISM IN BIOREACTOR USING DIFFERENT STRATEGY (L7)

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5.0

MATERIALS & APPARATUS

5.1

Materials 1) Distilled Water. 2) Nitrogen Gas (Purge Gas).

5.2

Apparatus 1) MINIFORS 2) Stop watch 3) (HI – BLOW HP 80) Linear Air Pump Aerator

Figure 4 - MINIFORS, The Stirred Tank Reactor Used In The Experiment

LAB REPORT ON GROWTH STUDY OF MICROORGANISM IN BIOREACTOR USING DIFFERENT STRATEGY (L7)

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6.0

METHODOLOGY

6.1

Effect of Aeration 1) The apparatus is set up by ensuring all the conditions is in well condition and well prepared. 2) pO2 probe is polarized for two hours before the main experiment is started. 3) The agitation parameter is set up at 400 rpm and the temperature parameter is set up at 30°C. 4) The pump is then switched off. 5) The first aeration parameter is set up at 0.5 L/min and prepared for 2 – point calibration. The setting is done before the purging using nitrogen gas. 6) Then, nitrogen gas is purged on the system until the value of the partial pressure of oxygen inside the system becomes 0%. 7) The nitrogen gas valve is then closed and the tube attached to the equipment is detached from the reactor. The pump is then switched back on allowing the aeration of air inside the reactor. 8) The actual dissolved oxygen concentration, pO2 (%) is recorded every 5 seconds until the reading reached to pO2 = 100%. 9) Step 5 until Step 8 is repeated for different aeration parameter value which are 1.0 L/min, 1.5 L/min, 2.0 L/min and 2.5 L/min.

LAB REPORT ON GROWTH STUDY OF MICROORGANISM IN BIOREACTOR USING DIFFERENT STRATEGY (L7)

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6.2

Effect of Agitation 1) The apparatus is set up by ensuring all the conditions is in well condition and well prepared. 2) pO2 probe is polarized for two hours before the main experiment is started. 3) The aeration parameter is set up at 2.0 L/min and the temperature parameter is set up at 30°C. 4) The pump is then switched off. 5) The first agitation parameter is set up at 200 rpm and prepared for 2 – point calibration. The setting is done before the purging using nitrogen gas. 6) Then, nitrogen gas is purged on the system until the value of the partial pressure of oxygen inside the system becomes 0%. 7) The nitrogen gas valve is then closed and the tube attached to the equipment is detached from the reactor. The pump is then switched back on allowing the aeration of air inside the reactor. 8) The actual dissolved oxygen concentration, pO2 (%) is recorded every 5 seconds until the reading reached to a constant value. The reading is stopped after three consecutive reading yields to the same value. 9) Step 5 until Step 8 is repeated for different agitation parameter value which are 200 rpm, 400 rpm, 600 rpm, 800 rpm and 1000 rpm.

LAB REPORT ON GROWTH STUDY OF MICROORGANISM IN BIOREACTOR USING DIFFERENT STRATEGY (L7)

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6.3

Effect of Tenperature 1) The apparatus is set up by ensuring all the conditions is in well condition and well prepared. 2) pO2 probe is polarized for two hours before the main experiment is started. 3) The aeration parameter is set up at 2.0 L/min and the agitation parameter is set up at 400 rpm. 4) The pump is then switched off. 5) The first temperature parameter is set up at 35°C and prepared for 2 – point calibration. The setting is done before the purging using nitrogen gas. 6) Then, nitrogen gas is purged on the system until the value of the partial pressure of oxygen inside the system becomes 0%. 7) The nitrogen gas valve is then closed and the tube attached to the equipment is detached from the reactor. The pump is then switched back on allowing the aeration of air inside the reactor. 8) The actual dissolved oxygen concentration, pO2 (%) is recorded every 5 seconds until the reading reached to a constant value. The reading is stopped after five consecutive reading yields to the same value. 9) Step 5 until Step 8 is repeated for different agitation parameter value which are 40°C, 45°C and 50°C.

LAB REPORT ON GROWTH STUDY OF MICROORGANISM IN BIOREACTOR USING DIFFERENT STRATEGY (L7)

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7.0

RESULTS

Table 2 – Effect on Aeration at Constant Temperature = 30°C and Agitation = 400 rpm Aeration (L/min)

0.5

1

1.5

2

2.5

0.5

1

Actual dissolved oxygen Time, t (s)

1.5

2

2.5

0.5

1

2

2.5

ln (C* - CL)

C* - CL

concentration, CL (%)

1.5

0

0

0

0

0

0

100.00

100.00

100.00

100.00

100.00

4.61

4.61

4.61

4.61

4.61

5

3.91

1.32

0.96

1.53

0.74

96.09

98.68

99.04

98.47

99.26

4.57

4.59

4.60

4.59

4.60

10

6.98

4.46

3.77

6.67

4.79

93.02

95.54

96.23

93.33

95.21

4.53

4.56

4.57

4.54

4.56

15

9.94

5.1

7.24

12.9

12.5

90.06

94.90

92.76

87.10

87.50

4.50

4.55

4.53

4.47

4.47

20

12.9

10.4

17.9

20.4

20.8

87.10

89.60

82.10

79.60

79.20

4.47

4.50

4.41

4.38

4.37

25

16

15.6

18.5

29.1

30

84.00

84.40

81.50

70.90

70.00

4.43

4.44

4.40

4.26

4.25

30

19.5

22.9

33.3

36.4

37.9

80.50

77.10

66.70

63.60

62.10

4.39

4.35

4.20

4.15

4.13

35

22.6

28.5

41.9

44.7

46.4

77.40

71.50

58.10

55.30

53.60

4.35

4.27

4.06

4.01

3.98

40

25.7

34.8

47.3

51.9

53.3

74.30

65.20

52.70

48.10

46.70

4.31

4.18

3.96

3.87

3.84

45

28.7

41

53.8

56.1

60.7

71.30

59.00

46.20

43.90

39.30

4.27

4.08

3.83

3.78

3.67

50

31.5

46.6

60.2

63.8

66.5

68.50

53.40

39.80

36.20

33.50

4.23

3.98

3.68

3.59

3.51

55

34.4

51.8

64.5

68.7

71.6

65.60

48.20

35.50

31.30

28.40

4.18

3.88

3.57

3.44

3.35

60

37.1

56.7

68.5

73.2

76.5

62.90

43.30

31.50

26.80

23.50

4.14

3.77

3.45

3.29

3.16

65

39.4

62.1

73.2

77.3

80.7

60.60

37.90

26.80

22.70

19.30

4.10

3.63

3.29

3.12

2.96

70

42.3

65.2

76.7

80.9

84.3

57.70

34.80

23.30

19.10

15.70

4.06

3.55

3.15

2.95

2.75

12

Aeration (L/min)

0.5

1

1.5

2

2.5

0.5

1

Actual dissolved oxygen Time, t (s)

1.5

2

2.5

0.5

1

2

2.5

ln (C* - CL)

C* - CL

concentration, CL (%)

1.5

75

44.8

68.9

80

84

87.3

55.20

31.10

20.00

16.00

12.70

4.01

3.44

3.00

2.77

2.54

80

46.7

72.3

82.9

86.7

90

53.30

27.70

17.10

13.30

10.00

3.98

3.32

2.84

2.59

2.30

85

49

75.4

85.4

89.3

92.3

51.00

24.60

14.60

10.70

7.70

3.93

3.20

2.68

2.37

2.04

90

51.2

78.3

87.6

91.5

94.2

48.80

21.70

12.40

8.50

5.80

3.89

3.08

2.52

2.14

1.76

95

53.2

80.8

89.8

93.4

95.9

46.80

19.20

10.20

6.60

4.10

3.85

2.95

2.32

1.8...