Downstream Processing Objective Questions and Answers

22. Micro filtration refers to the separation of suspended material such as bacteria by using a membrane with spore sizes of

23. Start up expenses in a fermentation industry varies from

A. 0-5% of the capital cost

B. 10-15% of the capital cost

C. 5-10% of the capital cost

D. 15-20% of the capital cost

Discussion

24. The solvent flux across the membrane can be expressed as (where A is the area, Lp is the membrane permeability, σ is the reflection point, Δp is applied pressure and Δπ is the osmotic pressure)

A. J = Lp(Δp - σΔπ)

B. J/A = Lp(Δp - σΔπ)

C. J = Lp/σΔπ

D. J/A = Lp/Δp

Discussion

25. Which of the following is considered as a pretreatment to the biological feeds?

A. Heating to denature the proteins

B. Addition of filter aids to increase the porosity

C. Addition of electrolytes

D. All of the above

Discussion

26. For the extractions operation, the selectivity should be

27. The purity of a solute collected between two times t1 and t2 during chromatographic separation can be calculated as

A. amount of solute eluted - amount of impurity eluted

B. amount of solute eluted / amount of impurity eluted

C. amount of solvent eluted + amount of impurity eluted

D. amount of solvent eluted / amount of impurity eluted

Discussion

28. Chromatography is based on the

A. different rate of movement of the solute in the column

B. separation of one solute from other constituents by being captured on the adsorbent

C. different rate of movement of the solvent in the column

D. any of the above

Discussion

Biochemical Engineering Objective Questions { Downstream Processing }