Question

Membrane filters are more efficient than depth filters.

(a) True

(b) False

The question was posed to me in an online interview.

My doubt is from Sterilisation in section Reactor Engineering of Bioprocess Engineering

Answer 1

Correct option is (a) True

Easy explanation: Depth filters do not perform well if there are large fluctuations in flow rate or if the air is wet; liquid condensing in the filter increases the pressure drop, causes channelling of the gas flow, and provides a pathway for organisms to grow through the bed, Whereas, Membrane filter cartridges typically contain a pleated, hydrophobic filter with small and uniformly-sized pores 0.45 pm or less in diameter. The hydrophobic nature of the surface minimises problems with filter wetting while the pleated configuration allows a high filtration area to be packed into a small cartridge volume.