After filtration, the water is disinfected by chlorine.
Following the filtration stage in water treatment, a crucial step is taken to ensure the safety and potability of the water before it reaches consumers. This essential process is disinfection.
Disinfection by Chlorine
According to the provided reference, after filtration, the water is disinfected by chlorine. Disinfection is vital for killing or inactivating harmful microorganisms, such as bacteria, viruses, and protozoa, that may still be present in the water even after sedimentation and filtration.
Chlorine is a widely used disinfectant in water treatment due to its effectiveness and residual protection. It works by oxidizing organic and inorganic matter and disrupting the cellular functions of microorganisms.
Why Disinfection is Important
Even though sedimentation and filtration remove many impurities, including larger particles and some microbes, disinfection provides an additional layer of protection against waterborne diseases. Without effective disinfection, water could still pose health risks from pathogens.
Typical Water Treatment Stages
While the reference specifically highlights disinfection by chlorine after filtration, it's helpful to see where this fits into a more comprehensive overview of standard water treatment processes.
| Stage | Description | Purpose |
|---|---|---|
| Flocculation | Water is gently stirred after adding chemicals. | To form large, settleable particles (flocs) from smaller ones. |
| Sedimentation | Water flows slowly through tanks, allowing flocs to settle. | To remove the majority of the formed flocs. |
| Filtration | Water passes through filters (sand, gravel, charcoal). | To remove remaining suspended particles and some microbes. |
| Disinfection | Chemicals (like chlorine) or UV light are applied. | To kill or inactivate remaining pathogens. |
| Further Treatment (Optional) | pH adjustment, fluoridation, etc. | To improve taste, odor, and add beneficial substances. |
As the reference states, filtration follows sedimentation, and after filtration the water is disinfected by chlorine. This sequence is a common and effective approach in treating water for public supply.
Key Takeaways
- The immediate process after filtration, as per the reference, is disinfection.
- Chlorine is used for this disinfection step.
- Disinfection is critical for eliminating remaining harmful microorganisms.
- This ensures the water is safe for consumption.
By disinfecting the water after filtration, treatment plants provide a significant barrier against waterborne illnesses, safeguarding public health.
