Sea water can be purified by :

Question

Accepted Answer

Sea water can be purified by reverse osmosis, which is the correct answer (Option 2). Reverse osmosis is a highly effective method for desalinating sea water, making it suitable for drinking and other uses. This process involves forcing sea water through a semi-permeable membrane that allows water molecules to pass through while blocking salts and other impurities. As a result, the water that emerges on the other side of the membrane is significantly purified and desalinated.

Now, let's explain why the other options are incorrect:

1. **Filtration**: Filtration is a process that removes particles and suspended solids from water by passing it through a filter medium. However, it is not effective for removing dissolved salts and other small molecules found in sea water. Therefore, filtration alone cannot purify sea water to make it potable.

3. **UV radiation**: UV radiation is used to disinfect water by killing bacteria and viruses. While it is effective for sterilizing water, it does not remove salts or other dissolved impurities from sea water. Thus, UV radiation cannot purify sea water in the context of desalination.

4. **Osmosis**: Osmosis is a natural process where water moves from a region of low solute concentration to a region of high solute concentration through a semi-permeable membrane. This process does not purify sea water; in fact, it would cause water to move into the sea water, increasing its salinity. Therefore, osmosis is not a method for purifying sea water.

In conclusion, reverse osmosis is the correct and most effective method for purifying sea water, as it specifically targets and removes dissolved salts and impurities, making it suitable for consumption and other uses.