Question

The term kLa during operation of bioreactors refers to:

• A. Liquid-liquid mass transfer coefficient
• B. Distribution of gas bubble size as a function of mixing
• C. Volumetric oxygen mass transfer coefficient
• D. Dankwerts gas-liquid interfacial energy coefficient

Hint:

\( k_La \) measures how effectively oxygen transfers from the gas to the liquid phase in bioreactors.

Answer 1

The Correct Option is C

Step 1: Understanding kLa 
The term \( k_La \) refers to the volumetric mass transfer coefficient, which measures the rate of oxygen transfer into the liquid phase from the gas phase in a bioreactor. 
Step 2: Evaluating the Options 
- Liquid-liquid mass transfer coefficient: Involves transfer between two liquids, not relevant to \( k_La \). 
- Distribution of gas bubble size: Related to aeration but does not define \( k_La \). 
- Volumetric oxygen mass transfer coefficient: Correct, as \( k_La \) represents oxygen transfer efficiency. 
- Dankwerts gas-liquid interfacial energy coefficient: Relates to the interfacial area, not directly to \( k_La \). 
Step 3: Conclusion 
The correct answer is the volumetric oxygen mass transfer coefficient.