Introduction

Water treatment plants are facilities where water is treated to make it safe for human consumption. During the treatment process, different chemicals are added to the water, and one of them is lime or calcium oxide. Why is lime used in a water plant? This article will explore the benefits of using lime in a water treatment plant.

1. pH Adjustment

One of the primary reasons why lime is used in water treatment plants is to adjust the pH of the water. The pH level of water is a measurement of how acidic or basic the water is, and it is essential to maintain an appropriate range of pH levels. The ideal pH range for drinking water is between 6.5 and 8.5. If water is too acidic (pH <6.5), it can be corrosive and can cause damage to pipes and fixtures. On the other hand, if water is too alkaline (pH>8.5), it can have a bitter taste, and it can also cause scaling on pipes and fixtures. By adding lime to the water, water treatment plants can adjust the pH levels to within the ideal range.

2. Softening Water

Hard water is water that has a high concentration of minerals, such as calcium and magnesium. Hard water can cause problems, such as scaling on pipes and fixtures and reduced soap efficiency. Lime is an effective agent for softening water, as it reacts with these minerals and precipitates them out of the water. The result is soft water that does not cause scaling or soap efficiency problems. In addition, soft water is better for people with eczema and other skin conditions.

3. Coagulation and Flocculation

Coagulation and flocculation are processes used to remove impurities, such as dirt, sand, and particles, from water. During coagulation, chemicals, such as alum or ferric chloride, are added to the water, which helps in clumping together the impurities. Flocculation is the process of gently mixing the water to help the clumps of impurities come together and form larger particles called flocs. Lime is often added to the water during coagulation and flocculation process to enhance the process and improve the clarity of the water.

4. Disinfection

Disinfection is the process of killing or inactivating harmful bacteria and viruses in water. The most common method of disinfection is chlorination, where chlorine is added to the water to kill the harmful microorganisms. However, during the chlorination process, a byproduct known as trihalomethanes (THMs) is produced, which can be harmful to human health. By adding lime to the water, water treatment plants can reduce the formation of THMs, which makes the water safer for human consumption.

Conclusion

Lime is an essential chemical in the water treatment process. It helps to adjust the pH levels of water, soften hard water, enhance coagulation and flocculation, and reduce the formation of harmful byproducts during the chlorination process. Overall, the addition of lime to the water makes it safer, cleaner, and more pleasant to drink.