How is filtration used in water purification?

Filtration in water purification is used to remove solid impurities, bacteria, and other contaminants from the water.

Filtration is a crucial step in the process of water purification. It involves passing the water through a porous material, or filter, which traps and removes solid impurities, bacteria, and other contaminants. The size of the pores in the filter determines what size particles will be removed from the water. The smaller the pores, the more impurities can be filtered out.

There are different types of filtration used in water purification. These include screen filters, depth filters, and membrane filters. Screen filters are the simplest type, using a screen with holes of a certain size to filter out larger particles. Depth filters use a thick layer of material, such as sand or activated carbon, to trap smaller particles. Membrane filters use a thin layer of material with very small pores to remove even smaller particles and bacteria.

Filtration is often used in combination with other water purification methods. For example, it may be used after coagulation and flocculation, which are processes that cause impurities to clump together into larger particles that can be more easily filtered out. Filtration may also be used before disinfection, to remove impurities that could interfere with the disinfection process.

In addition to removing impurities, filtration can also improve the taste, smell, and appearance of water. For example, activated carbon filters can remove chlorine and other chemicals that can give water an unpleasant taste or smell. They can also remove particles that can make water look cloudy or discoloured.

Overall, filtration is a vital part of water purification, helping to ensure that the water we drink is clean and safe.