Coagulation is the process by which Alum cleans the muddy water. Alum, also known as aluminum sulfate, is a chemical compound that has the ability to attract and bind with suspended particles in water. This process helps in removing impurities and making the water clear.

Coagulation Process:
1. Introduction:
Coagulation is a key step in the water treatment process, especially when dealing with muddy or turbid water. It involves the addition of a coagulant, such as alum, to the water to destabilize and aggregate the suspended particles.

2. Destabilization of particles:
When alum is added to muddy water, it dissociates into aluminum ions (Al3+) and sulfate ions (SO42-). The aluminum ions have a positive charge, while the suspended particles in water have a negative charge. The aluminum ions neutralize the negative charges on the particles, leading to their destabilization.

3. Formation of flocs:
Once the particles are destabilized, they begin to come together and form larger aggregates called flocs. The flocs are formed due to the attractive forces between the alum ions and the suspended particles. These flocs are relatively larger in size and can be easily separated from the water.

4. Settling and sedimentation:
The water containing the flocs is then allowed to settle in a sedimentation tank. During this process, the flocs settle at the bottom of the tank due to their increased size and weight. This settling process is aided by gravity and takes some time, usually a few hours.

5. Filtration:
After the settling process, the water is passed through a filtration system to remove any remaining suspended particles. The filtration system may consist of layers of sand, gravel, and activated carbon, which effectively trap and remove the flocs and other impurities.

6. Disinfection:
Once the water has been filtered, it undergoes disinfection to kill any remaining bacteria, viruses, or other microorganisms. Common disinfection methods include chlorination, UV treatment, or ozonation.

Conclusion:
In summary, the process of coagulation using alum helps in cleaning muddy water by destabilizing the suspended particles, forming larger flocs, settling them out, and finally filtering the water to remove impurities. This process is an important step in water treatment to ensure the supply of clean and safe drinking water.