What Kind of Chemicals Do Water Treatment Plants Use?

Water is essential for life, and access to clean water is a basic human right. Water treatment plants play a crucial role in ensuring that we have access to clean water for our daily needs. Water treatment plants use a variety of chemicals to purify and sanitize the water before it is released into the distribution system.

Chlorine

Chlorine is the most commonly used chemical in water treatment plants. It is a powerful disinfectant that kills bacteria, viruses, and other microorganisms that can cause waterborne illnesses. Chlorine is added in the form of a gas or liquid, and it reacts with the organic matter in the water to form hypochlorous acid, which kills the microorganisms. The amount of chlorine added is carefully monitored to ensure that it is sufficient to kill the microorganisms but not enough to cause harm to humans. Chlorine can have a strong smell and taste, but the levels are typically low enough to be safe for consumption.

Aluminum Sulfate (Alum)

Aluminum sulfate, also known as alum, is a coagulant that is added to the water to remove the impurities that contribute to cloudiness and turbidity. Alum reacts with the impurities to form heavy particles that settle to the bottom of the treatment tank, making it easier to remove them from the water. Alum is added in a powdered form, and the dosage is based on the level of impurities in the water. After the particles have settled, the clear water is removed from the top of the tank for further treatment. Alum is safe for human consumption in small amounts.

Lime

Lime, also known as calcium hydroxide, is added to the water to help adjust the pH level. The pH level is a measure of the acidity or alkalinity of the water, and it needs to be carefully controlled to ensure that it is within a safe range for human consumption. Lime is added in a powdered form and reacts with the water to raise the pH level. The amount of lime added is carefully controlled to ensure that the pH level remains within the safe range. Lime can also help to remove impurities and metals from the water.

Sodium Hypochlorite (Bleach)

Sodium hypochlorite, also known as bleach, is another disinfectant that is sometimes used in water treatment plants. Bleach is added in liquid form, and it works in the same way as chlorine to kill microorganisms in the water. Bleach has a similar odor and taste as chlorine, but its effectiveness can be impacted by factors such as temperature and pH level. Bleach is not used as widely as chlorine due to its lower effectiveness and shorter shelf life.

Conclusion

Water treatment plants use a variety of chemicals to ensure that the water we consume is safe and free from harmful contaminants. Chlorine is the most commonly used chemical for disinfection, while alum is used to remove impurities and lime is used to adjust the pH level. Sodium hypochlorite is sometimes used as an alternative to chlorine, but it has lower effectiveness and is not as widely used. The dosage and application of these chemicals are carefully monitored to ensure that they are safe for human consumption. Without these chemicals, we would not have access to the clean water that is essential for our daily needs.