What is the purpose of chlorination in water treatment?

• A. To reduce turbidity
• B. To eliminate bacteria and pathogens
• C. To balance pH levels
• D. To remove heavy metals

Answer: (B)

The primary purpose of chlorination in water treatment is to eliminate bacteria and pathogens. Chlorine acts as a powerful disinfectant, effectively killing a wide range of microorganisms that can cause disease, thereby ensuring that water is safe for human consumption. This process is crucial in maintaining public health, particularly in municipal water supply systems where water is distributed to large populations. Chlorination not only destroys harmful organisms present in the water but also helps to prevent future contamination as the residual chlorine can inhibit regrowth of pathogens.

While other aspects of water treatment, such as balancing pH levels and removing heavy metals, are important, they are achieved through different chemical processes or processes entirely separate from chlorination. For instance, turbidity reduction is typically handled through sedimentation and filtration technologies rather than disinfection methods like chlorination. Thus, the distinctive role of chlorination is in disinfection, which is why it is recognized as a fundamental step in ensuring safe drinking water.