Water disinfection is a process used to eliminate or reduce microrganisms in water such as bacteria, viruses, fungi, and parasites. There are many methods of water disinfection, but they can all be divided into two main categories: physical methods and chemical methods. Each method has its advantages and disadvantages.

Physical Methods of Water Disinfection

• Filtration: This method includes passing water through a physical medium that traps and removes particles from the water. This includes sediment filtration, ultrafiltration, and reverse osmosis.
• Ultraviolet (UV) Radiation: This method uses UV light to kill microorganisms. The light works by damaging the nucleic acids in the cells of the microbe, stopping them from reproducing.
• Ionization: This method involves passing the water through an electrical field to produce ions. The ions disrupt the microorganisms, ultimately resulting in their death.

Chemical Methods of Water Disinfection

• Chlorination: This is the most common method of water disinfection. It involves adding chlorine compounds to the water, which affects the cell membrane of the microorganisms, preventing them from reproducing and leading to their death.
• Ozone Treatment: This method involves using ozone gas to oxidize and disinfect the water. The ozone destroys the membrane of the microorganism, preventing them from reproducing.
• Bromine Treatment: This uses bromine compounds to disinfect the water. The bromine reacts with the cell membrane of the microorganisms, leading to their death.

All of the above methods can be used to disinfect water, but there is one method that is not used: desalination. Desalination is the process of removing salt from water, and it is not used for disinfection because it does not remove microorganisms from the water.