Question

Arrange the various membrane process in descending order on the basis of operating pressure.
A. Ultrafiltration (UF)
B. Nanofiltration (NF)
C. Microfiltration (MF)
D. Reverse osmosis (RO)

• A. A, B, C, D
• B. D, A, C, B
• C. A, C, B, D
• D. D, C, B, A

Hint:

Smaller pores → higher pressure required.

Answer 1

The Correct Option is D

Concept: Membrane processes differ based on pore size and operating pressure.

Step 1: Reverse osmosis.

• Highest pressure

Step 2: Nanofiltration.

• Moderate-high pressure

Step 3: Ultrafiltration.

• Medium pressure

Step 4: Microfiltration.

• Lowest pressure

Step 5: Descending order.
\[ RO > NF > UF > MF \] Conclusion: Option (4) correct.