What membrane process will remove dissolved solids?

What membrane process will remove dissolved solids?

• A. Microfiltration
• B. Reverse osmosis
• C. Nanofiltration
• D. Ultrafiltration

Answer: (B)

The main idea is that dissolved solids—like salts and other ions—are very small and require a tight, pressure-driven barrier to be removed. Reverse osmosis uses a dense semipermeable membrane and high pressure to push water molecules through while blocking most dissolved substances. This yields permeate with very low dissolved solids, making it highly effective for desalination and removing salts. Other membrane processes differ in what they block: ultrafiltration and microfiltration have larger pores, so they mainly remove suspended particles, bacteria, and large organic molecules, not dissolved salts. Nanofiltration can remove some multivalent ions and smaller organics, but not all dissolved solids like reverse osmosis does.

The main idea is that dissolved solids—like salts and other ions—are very small and require a tight, pressure-driven barrier to be removed. Reverse osmosis uses a dense semipermeable membrane and high pressure to push water molecules through while blocking most dissolved substances. This yields permeate with very low dissolved solids, making it highly effective for desalination and removing salts.

Other membrane processes differ in what they block: ultrafiltration and microfiltration have larger pores, so they mainly remove suspended particles, bacteria, and large organic molecules, not dissolved salts. Nanofiltration can remove some multivalent ions and smaller organics, but not all dissolved solids like reverse osmosis does.