![Page 1: 1 Welcome to Industrial Bioprocessing and Bioremediation ! (Environmental Biotechnology) Example processes: How to: make renewable biogas from organic](https://reader030.vdocument.in/reader030/viewer/2022020219/56649f115503460f94c24550/html5/thumbnails/1.jpg)
1
Welcome to Industrial Bioprocessing and
Bioremediation !(Environmental Biotechnology)
Example processes: How to:
•make renewable biogas from organic wastes.
•remove polluting nutrients from wastewater
•breed microalgae for food or energy production
•make beer, yoghurt,
•mine ores by using bacteria (bioleaching)
•understand microbial processes in ocean, soil and bioreactors
![Page 2: 1 Welcome to Industrial Bioprocessing and Bioremediation ! (Environmental Biotechnology) Example processes: How to: make renewable biogas from organic](https://reader030.vdocument.in/reader030/viewer/2022020219/56649f115503460f94c24550/html5/thumbnails/2.jpg)
2
Fundamentals taught
Bioprocesses convert S to P
How much S to P?
Mass balance
How much hydrogen gas can we make as fuel from fermenting sugars ?
How much oxygen is needed for respiration?
How much electricity can be formed from sugar ?
![Page 3: 1 Welcome to Industrial Bioprocessing and Bioremediation ! (Environmental Biotechnology) Example processes: How to: make renewable biogas from organic](https://reader030.vdocument.in/reader030/viewer/2022020219/56649f115503460f94c24550/html5/thumbnails/3.jpg)
3
Fundamentals taught
Bioprocesses convert S to P
Sugar to energy (biogas, ethanol, hydrogen, electricity)
Pollutants to harmless substances (dechlorination, degradation, dirty water to clean water
Need to be able to predict (modelling)
Quantify (rates)
Understanding (driving force, equilibrium)
![Page 4: 1 Welcome to Industrial Bioprocessing and Bioremediation ! (Environmental Biotechnology) Example processes: How to: make renewable biogas from organic](https://reader030.vdocument.in/reader030/viewer/2022020219/56649f115503460f94c24550/html5/thumbnails/4.jpg)
4
Fundamentals taught
Bioprocesses questions:
Why ?
How ?
How fast?
What mechanism ?
Modelling
![Page 5: 1 Welcome to Industrial Bioprocessing and Bioremediation ! (Environmental Biotechnology) Example processes: How to: make renewable biogas from organic](https://reader030.vdocument.in/reader030/viewer/2022020219/56649f115503460f94c24550/html5/thumbnails/5.jpg)
5
Learning tools used
Bioprocess analysis (theory) Computer simulation
Bioprocess execution and analysis (Chemostat project)
Spreadsheets for data processing and analysis
Peer reviewed websites of scientific analysis of literature
Using computer learning activities
Industry trip
Focussed scientific writing.
![Page 6: 1 Welcome to Industrial Bioprocessing and Bioremediation ! (Environmental Biotechnology) Example processes: How to: make renewable biogas from organic](https://reader030.vdocument.in/reader030/viewer/2022020219/56649f115503460f94c24550/html5/thumbnails/6.jpg)
6
Link between Research and Teaching
A number of undergraduates honours PhD Senior Engineers (Water Corporation, Design companies, Bioprocess Operators)
Teaching topics drawn from own research projects and publications.
Input from current researchers into the project
Link to industry.
So, on many of the topics you talk to science experts, not just “teachters that obtained their knowledge from books”
![Page 7: 1 Welcome to Industrial Bioprocessing and Bioremediation ! (Environmental Biotechnology) Example processes: How to: make renewable biogas from organic](https://reader030.vdocument.in/reader030/viewer/2022020219/56649f115503460f94c24550/html5/thumbnails/7.jpg)
7
Bioprocessing – Biotechnology: Make money from bioprocesses
Inputs are of lower value than outputs (products)
Computer based learning activities (CBLA) are on
http://sphinx.murdoch.edu.au/units/extern/BIO301/teach/index.htm
![Page 8: 1 Welcome to Industrial Bioprocessing and Bioremediation ! (Environmental Biotechnology) Example processes: How to: make renewable biogas from organic](https://reader030.vdocument.in/reader030/viewer/2022020219/56649f115503460f94c24550/html5/thumbnails/8.jpg)
8
![Page 9: 1 Welcome to Industrial Bioprocessing and Bioremediation ! (Environmental Biotechnology) Example processes: How to: make renewable biogas from organic](https://reader030.vdocument.in/reader030/viewer/2022020219/56649f115503460f94c24550/html5/thumbnails/9.jpg)
9
![Page 10: 1 Welcome to Industrial Bioprocessing and Bioremediation ! (Environmental Biotechnology) Example processes: How to: make renewable biogas from organic](https://reader030.vdocument.in/reader030/viewer/2022020219/56649f115503460f94c24550/html5/thumbnails/10.jpg)
10
![Page 11: 1 Welcome to Industrial Bioprocessing and Bioremediation ! (Environmental Biotechnology) Example processes: How to: make renewable biogas from organic](https://reader030.vdocument.in/reader030/viewer/2022020219/56649f115503460f94c24550/html5/thumbnails/11.jpg)
11
![Page 12: 1 Welcome to Industrial Bioprocessing and Bioremediation ! (Environmental Biotechnology) Example processes: How to: make renewable biogas from organic](https://reader030.vdocument.in/reader030/viewer/2022020219/56649f115503460f94c24550/html5/thumbnails/12.jpg)
12
![Page 13: 1 Welcome to Industrial Bioprocessing and Bioremediation ! (Environmental Biotechnology) Example processes: How to: make renewable biogas from organic](https://reader030.vdocument.in/reader030/viewer/2022020219/56649f115503460f94c24550/html5/thumbnails/13.jpg)
13
![Page 14: 1 Welcome to Industrial Bioprocessing and Bioremediation ! (Environmental Biotechnology) Example processes: How to: make renewable biogas from organic](https://reader030.vdocument.in/reader030/viewer/2022020219/56649f115503460f94c24550/html5/thumbnails/14.jpg)
Lecture overview L1-3
Lecture 1: Intro, study guide, what is a bioreactor,Learning by interacting
Lecture 2: What is diffusion, how can we predict the behaviour of a randomly moving molecule? moving dots, entropy, driving force, equilibrium, rate of diffusion, first order kinetics, kLa
Lecture 3: oxygen transfer rate, kLa value. Graphical method of determining the kLa. Mathematical (2 point) determination of kLACalculation and prediction of oxygen transfer as function of DO. Oxygen transfer efficiency. Bacterial OUR, DO. steady state
14
![Page 15: 1 Welcome to Industrial Bioprocessing and Bioremediation ! (Environmental Biotechnology) Example processes: How to: make renewable biogas from organic](https://reader030.vdocument.in/reader030/viewer/2022020219/56649f115503460f94c24550/html5/thumbnails/15.jpg)
Molecular diffusion relies on random movement resulting in uniform distribution of molecules
15
![Page 16: 1 Welcome to Industrial Bioprocessing and Bioremediation ! (Environmental Biotechnology) Example processes: How to: make renewable biogas from organic](https://reader030.vdocument.in/reader030/viewer/2022020219/56649f115503460f94c24550/html5/thumbnails/16.jpg)
Oxygen Transfer Rate (OTR)Overview
Diffusion, how does it work, how can we predict it?
Diffusion is random …. and yet predictable.A simple model simulation can show that although the diffusion movement is random, it can be precisely predicted for large number of molecules (e.g. Fick’s law of diffusion)
16
![Page 17: 1 Welcome to Industrial Bioprocessing and Bioremediation ! (Environmental Biotechnology) Example processes: How to: make renewable biogas from organic](https://reader030.vdocument.in/reader030/viewer/2022020219/56649f115503460f94c24550/html5/thumbnails/17.jpg)
Oxygen Transfer Rate (OTR)(diffusion, convection)
LowOTR High
OTR
Transfer by diffusion is extremely slowand depends on surface area
Wind
Oxygen transfer by convection(turbulences) is more efficient
Air In
••
•
••• • ••
• • Bioreactors combine maximum convectionwith maximum diffusion
• Course bubbles cause more convection,fine bubbles more diffusion
How soluble is oxygen?17
![Page 18: 1 Welcome to Industrial Bioprocessing and Bioremediation ! (Environmental Biotechnology) Example processes: How to: make renewable biogas from organic](https://reader030.vdocument.in/reader030/viewer/2022020219/56649f115503460f94c24550/html5/thumbnails/18.jpg)
The net transfer of oxygen from
•gas phase to solution reaches a dynamic equilibrium
•O2 input = O2 output
•equilibrium results in defined saturation concentration (cs).
•The saturation concentration is also the oxygen solubility
•How soluble is oxygen?
Oxygen solubility (cS)
18
![Page 19: 1 Welcome to Industrial Bioprocessing and Bioremediation ! (Environmental Biotechnology) Example processes: How to: make renewable biogas from organic](https://reader030.vdocument.in/reader030/viewer/2022020219/56649f115503460f94c24550/html5/thumbnails/19.jpg)
Oxygen is not very polar poorly soluble in water.
Oxygen Solubility is described by Henry’s Law which applies to all gases
p = k*cSp = partial pressure of oxygenk = constant depending on gas type, solution
and temperaturecS = concentration of oxygen dissolved in water
• Meaning: The amount of oxygen which dissolves in water is proportional to the amount of oxygen molecules present per volume of the gas phase.
• Partial pressure ~ number of O2 molecules per volume of gasincreases with O2 concentration in gas
increases with total gas pressure
How to calculate partial pressure? (refer to CBLA)
Oxygen solubility (cS)
19
![Page 20: 1 Welcome to Industrial Bioprocessing and Bioremediation ! (Environmental Biotechnology) Example processes: How to: make renewable biogas from organic](https://reader030.vdocument.in/reader030/viewer/2022020219/56649f115503460f94c24550/html5/thumbnails/20.jpg)
Examples of using the proportionality between partial pressure of oxygen in the atmosphere and the saturation concentration cS:
p = k*cSp = partial pressure of oxygenk = constant depending on gas type, solution
and temperaturecS = concentration of oxygen dissolved in water
• If the reactor is operated under 2 times atmospheric pressure (200kPa instead of 100 kPa air pressure), the new saturation concentration will be abou 16 mg/L instead of 8 mg/L.
• If air (partial pressure = 0.21* 100 kPa) is replaced by pure oxygen atmosphere (partial pressure 100kPa) the oxygen saturation concentration is about 40 mg/L (more precise 8*100/21) instead of 8 mg/L.
How to calculate partial pressure? (refer to CBLA)
Oxygen solubility (cS)
20
![Page 21: 1 Welcome to Industrial Bioprocessing and Bioremediation ! (Environmental Biotechnology) Example processes: How to: make renewable biogas from organic](https://reader030.vdocument.in/reader030/viewer/2022020219/56649f115503460f94c24550/html5/thumbnails/21.jpg)
Effect of temperature
Oxygen solubility decreases with increasing temperature.
Overall: oxygen is poorly soluble (8mg/: at room temp.)
More important than solubility is oxygen supply rate (oxygen transfer rate OTR).
0
5
10
15
0 20 40 60
cs =468
(31.6 + T)
Oxy
gen
Sat
ura
tio
n
Co
nce
ntr
atio
n c
s (
mg
/L)
Temperature (°C)
Oxygen solubility (cS)
21
![Page 22: 1 Welcome to Industrial Bioprocessing and Bioremediation ! (Environmental Biotechnology) Example processes: How to: make renewable biogas from organic](https://reader030.vdocument.in/reader030/viewer/2022020219/56649f115503460f94c24550/html5/thumbnails/22.jpg)
Oxygen Transfer Rate (OTR)(gradient, driving force)
Question: What is the driving force for oxygen dissolution?
OTR At oxygen saturation concentration (cs): dynamic equilibrium exists between oxygen transferred from the air to water and vice versa. No driving force
Answer: The difference between cS and the actual dissolved oxygen concentration (cL) is the driving force. OTR is proportional to the that difference. Thus:
OTR ~ (cS – cL)
Need to determine the proportionality factor
22
![Page 23: 1 Welcome to Industrial Bioprocessing and Bioremediation ! (Environmental Biotechnology) Example processes: How to: make renewable biogas from organic](https://reader030.vdocument.in/reader030/viewer/2022020219/56649f115503460f94c24550/html5/thumbnails/23.jpg)
1. Deoxygenation (N2, sulfite + Co catalyst)2. Aeration and monitoring dissolved oxygen concentration (D.O. or cL) as function of time
3. OTR = slope of the aeration curve (mg/L.h or ppm/h)
Significance of OTR: critical to know and to control forall aerobic bioreactors
0 5 10
8 Air On
cL (
pp
m)
Time (min)
OTR – depends on DO (cL)
23
![Page 24: 1 Welcome to Industrial Bioprocessing and Bioremediation ! (Environmental Biotechnology) Example processes: How to: make renewable biogas from organic](https://reader030.vdocument.in/reader030/viewer/2022020219/56649f115503460f94c24550/html5/thumbnails/24.jpg)
OTR = kLa (cs - cL)
Mg/L/h h-1 mg/L
4. Observation: OTR decreases over time (and with incr. cL)
5. OTR is not a good measure of aeration capacity of a bioreactor
6. OTR is highest at cL = zero (Standard OTR)
7. OTR is zero at oxygen saturation concentrations (cs)
8. OTR is negatively correlated to cL
9. OTR is correlated to the saturation deficit (cs - cL),
which is the driving force for oxygen transfer
9. The factor of correlation is the volumetric mass transfer
coefficient kLa
OTR – depends on DO (cL)
24
![Page 25: 1 Welcome to Industrial Bioprocessing and Bioremediation ! (Environmental Biotechnology) Example processes: How to: make renewable biogas from organic](https://reader030.vdocument.in/reader030/viewer/2022020219/56649f115503460f94c24550/html5/thumbnails/25.jpg)
First: steep step in oxygen (top layer saturated, next layer oxygen free)
Then: buildup of a gradient of many layers.
Each layer is only slightly different from the next Transfer from layer to layer has little driving force.
Gradient build-up inhibits fast diffusion
OTR –Significance of gradient
25
![Page 26: 1 Welcome to Industrial Bioprocessing and Bioremediation ! (Environmental Biotechnology) Example processes: How to: make renewable biogas from organic](https://reader030.vdocument.in/reader030/viewer/2022020219/56649f115503460f94c24550/html5/thumbnails/26.jpg)
10. OTR is not a useful parameter for the assessment of the aeration capacity of a bioreactor. This is because it is
dependent on the oxygen concentration (cL)
11. The kLa value is a suitable parameter as it divides OTR by saturation deficit:
12. kLa = the key parameter oxygen transfer capacity. How to determine it?
OTR(cs - cL)
kLa =
26
![Page 27: 1 Welcome to Industrial Bioprocessing and Bioremediation ! (Environmental Biotechnology) Example processes: How to: make renewable biogas from organic](https://reader030.vdocument.in/reader030/viewer/2022020219/56649f115503460f94c24550/html5/thumbnails/27.jpg)
Lec 2 summary:
Oxygen is poorly soluble depending mainly on •partial pressure in headspace•Temperature
OTR is driven and proportional to driving force (cS-cL)
kLa is the proportionality factor (first order kinetics)
kLa describes the performance of a bioreactor to provideOxygen to microbes
Next lecture: quantify kLA
27
![Page 28: 1 Welcome to Industrial Bioprocessing and Bioremediation ! (Environmental Biotechnology) Example processes: How to: make renewable biogas from organic](https://reader030.vdocument.in/reader030/viewer/2022020219/56649f115503460f94c24550/html5/thumbnails/28.jpg)
Lec 3 outlook:
•Aeration curve•Quantify OTR at a given point of an aeration curve•Quick estimate of kLa•Graphical determination of kLa•Mathematical determination of kLa•Run computer simulation to obtain data•Oxygen transfer efficiency (OTE)•OTR proportional to cs-cL•OTR inverse proportional to cL
28
![Page 29: 1 Welcome to Industrial Bioprocessing and Bioremediation ! (Environmental Biotechnology) Example processes: How to: make renewable biogas from organic](https://reader030.vdocument.in/reader030/viewer/2022020219/56649f115503460f94c24550/html5/thumbnails/29.jpg)
OTR – Quick estimate of kLAExample: determine OTR at 6 mg/L
OTR is the slope of the tangent for each oxygen concentration
OTR = ∆ cL/ ∆ t = 5 mg/L/ 4.5 min = 1.1 mg/L/min = 66 mg/L/h
0 5 10
8 Air OncL
(m
g/L
)
Time (min)
6
4.5 min
5 mg/L
29
![Page 30: 1 Welcome to Industrial Bioprocessing and Bioremediation ! (Environmental Biotechnology) Example processes: How to: make renewable biogas from organic](https://reader030.vdocument.in/reader030/viewer/2022020219/56649f115503460f94c24550/html5/thumbnails/30.jpg)
kLa = OTR
= 66 ppm / h
(cs-cL)
= 3.3 h-1
(8 ppm – 6 ppm)
Q: Problem with this method?
A: based on one single OTR slope measurement and unreliable to obtain from real data.
OTR – quick estimate of kLA
Time
DO
30
![Page 31: 1 Welcome to Industrial Bioprocessing and Bioremediation ! (Environmental Biotechnology) Example processes: How to: make renewable biogas from organic](https://reader030.vdocument.in/reader030/viewer/2022020219/56649f115503460f94c24550/html5/thumbnails/31.jpg)
1. Monitor aeration curve
2. Determine graphically the OTR at various oxygen concentrations (cL)
8
2
4
6
0 5 10
3. Tabulate OTR and corresponding cL values
cL (
pp
m)
0.53.04.06.08.0
Time (min)
7.55.04.02.00.0
306050250
cL (mg/L) Cs - cL (mg/L) OTR (mg/L/h)
At 6 ppm: OTR = 25 mg/L/h
At 4 ppm: OTR = 50 mg/L/hAt 3 ppm: OTR = 60 mg/L/h
At 0.5 ppm: OTR = 30 ppm/h
OTR – Graphical determination of kLa
31
![Page 32: 1 Welcome to Industrial Bioprocessing and Bioremediation ! (Environmental Biotechnology) Example processes: How to: make renewable biogas from organic](https://reader030.vdocument.in/reader030/viewer/2022020219/56649f115503460f94c24550/html5/thumbnails/32.jpg)
0
50
100
0 2 4 6 8
4. Plot OTR values as a function of cs - cL.O
TR
(m
g/L
/h) Standard OTR
cs
cs- cL (mg/L)
5. A linear correlation exists between kLa and the saturation deficit (cs - cL) which is the driving force of the reaction.
6. The slope of the plot OTR versus cs - cL is the kLa value.
7. The standard OTR (max OTR) can be read from the intercept with the cs line. (Standard OTR = 100 ppm/h)
kLa = = 12 h-170 mg/L/h
6 mg/L
OTR – Graphical determination of kLa
32
![Page 33: 1 Welcome to Industrial Bioprocessing and Bioremediation ! (Environmental Biotechnology) Example processes: How to: make renewable biogas from organic](https://reader030.vdocument.in/reader030/viewer/2022020219/56649f115503460f94c24550/html5/thumbnails/33.jpg)
Mathematical Determination of kLa1. OTR is a change of cL over time, thus = dcL/dt
Integration gives2. kLa = dcL/dt
(cs- cL)
( )cs - co3. kLa = ln cs - ci
ti - to
( )8 - 3 ppm kLa = ln 8 - 6 ppm
10.5 - 6.1 min
= 0.21 min-1 = 12.5 h-1= ln 2.5
4.4 min
•
•D
isso
lved
Oxy
gen
Con
cent
ratio
n (m
g/L)
ci = 6
co = 3
to ti Time (min)
cs
33
![Page 34: 1 Welcome to Industrial Bioprocessing and Bioremediation ! (Environmental Biotechnology) Example processes: How to: make renewable biogas from organic](https://reader030.vdocument.in/reader030/viewer/2022020219/56649f115503460f94c24550/html5/thumbnails/34.jpg)
4. This method should be carried out for 3 to 4 different intervals. By aver
5. Once the kLa is known it allows to calculate the OTR at any given oxygen concentration:
OTR = kLa (cs - cL)
34
![Page 35: 1 Welcome to Industrial Bioprocessing and Bioremediation ! (Environmental Biotechnology) Example processes: How to: make renewable biogas from organic](https://reader030.vdocument.in/reader030/viewer/2022020219/56649f115503460f94c24550/html5/thumbnails/35.jpg)
Factors Affecting the Oxygen Transfer Coefficient kLa
kLa consists of:
• kL = resistance or thickness of boundary film• a = surface area
Bubble BulkLiquid
Cell
[Oxy
gen
]
Distance
Main boundary layer = steepest gradient→ rate controlling, driving force 35
![Page 36: 1 Welcome to Industrial Bioprocessing and Bioremediation ! (Environmental Biotechnology) Example processes: How to: make renewable biogas from organic](https://reader030.vdocument.in/reader030/viewer/2022020219/56649f115503460f94c24550/html5/thumbnails/36.jpg)
Effect of Fluid Composition on OTR
The transfer across this boundary layer increases with:
1) ↓ thickness of the film, thus ↑ degree of shearing (turbulence)
2) ↑ surface area
3) ↓ surface tension
4) ↓ viscosity (best in pure water)
5) ↓ salinity
6) ↓ concentration of chemicals or particles
7) detergents?
8) ↑ emulsifiers, oils, “oxygen vectors”
36
![Page 37: 1 Welcome to Industrial Bioprocessing and Bioremediation ! (Environmental Biotechnology) Example processes: How to: make renewable biogas from organic](https://reader030.vdocument.in/reader030/viewer/2022020219/56649f115503460f94c24550/html5/thumbnails/37.jpg)
Oxygen Transfer Efficiency (OTE)
OTE =oxygen transferred
oxygen supplied
Significance of OTE: economical, evaporation
Calculation of OTE (%):
% OTE =oxygen transferred (mol/L.h)
oxygen supplied (mol/L.h)X 100
Why do students find this type calculation difficult?Units are disregarded. Molecular weights are misused.
37
![Page 38: 1 Welcome to Industrial Bioprocessing and Bioremediation ! (Environmental Biotechnology) Example processes: How to: make renewable biogas from organic](https://reader030.vdocument.in/reader030/viewer/2022020219/56649f115503460f94c24550/html5/thumbnails/38.jpg)
Oxygen Transfer Efficiency (OTE)
A bioreactor ( 3 m3) is aerated with 200 L/min airflow. If the OTR is constant (100 mg/L/h) determine the %OTE.
1. Convert the airflow into an oxygen flow in mmol/L/h
200 L air /min = 12000 L air/h
= 2520 L O2/h
= 102.9 mol O2/h
= 34.3 mmol O2/L.h
(x 21%)
(÷ 24.5 L/mol)
(÷ 3000 L)
2. OTR
(x 60)
100 mg/L.h = 3.1 mmol O2/L.h (÷ 32 g/mol)
% OTE =3.1 (mmol/L.h)
34.3 (mol/L.h)X 100
= 9% 38
![Page 39: 1 Welcome to Industrial Bioprocessing and Bioremediation ! (Environmental Biotechnology) Example processes: How to: make renewable biogas from organic](https://reader030.vdocument.in/reader030/viewer/2022020219/56649f115503460f94c24550/html5/thumbnails/39.jpg)
Oxygen Transfer Efficiency (OTE)
OTE is dependent upon the cL in the same way than OTR
OTE decreases with increasing airflow(more oxygen is wasted)
% O
TE
5
10
Airflow
39
![Page 40: 1 Welcome to Industrial Bioprocessing and Bioremediation ! (Environmental Biotechnology) Example processes: How to: make renewable biogas from organic](https://reader030.vdocument.in/reader030/viewer/2022020219/56649f115503460f94c24550/html5/thumbnails/40.jpg)
Engineering Parameters Influencing OTR
Increase depth vessel
Decrease bubble size
Increase air flow rate
Increase stirring rate
Deeper vessel bubbles rise a long way ↑ OTR, OTE but more pressure required ↑ $$
Larger surface area ↑ OTR, OTEsmaller bubbles rise slower more gas hold up ↑ OTR, OTE
↑ Number of bubbles ↑ OTR but ↓ OTE
↑ turbulence ↓ thickness of boundary layer ↑ OTR, OTE
↓ Bubble size ↑ OTR, OTE 40
![Page 41: 1 Welcome to Industrial Bioprocessing and Bioremediation ! (Environmental Biotechnology) Example processes: How to: make renewable biogas from organic](https://reader030.vdocument.in/reader030/viewer/2022020219/56649f115503460f94c24550/html5/thumbnails/41.jpg)
Rate is proportional to concentration First order kinetics
Slope = kLa
max OTR
OT
R (
mg
/L.h
)
Dissolved oxygen [mg/L]
OTR = kLa (O2 saturation (cS) – O2 concentration (cL))
(first order kinetics)
Aeration Curve
Time
Dis
solv
ed O
xyg
enAir on(cs)
OTR – from aeration curve to kLa summary
41
![Page 42: 1 Welcome to Industrial Bioprocessing and Bioremediation ! (Environmental Biotechnology) Example processes: How to: make renewable biogas from organic](https://reader030.vdocument.in/reader030/viewer/2022020219/56649f115503460f94c24550/html5/thumbnails/42.jpg)
During aeration of oxygen free water, the dissolved oxygen increases in a characteristic way
OTR – Aeration curve from CBLA
42
![Page 43: 1 Welcome to Industrial Bioprocessing and Bioremediation ! (Environmental Biotechnology) Example processes: How to: make renewable biogas from organic](https://reader030.vdocument.in/reader030/viewer/2022020219/56649f115503460f94c24550/html5/thumbnails/43.jpg)
Can the relationship between rate and DO be expressed mathematically?
•Highest Rate at lowest dissolved oxygen concentration
•Rate of zero when DO reaches saturation concentration
OTR – aeration curve from CBLA
43