Consider the following statements regarding water treatment:
(A) Alum is added to water as a coagulating agent. (B) Residual chlorine is considered as a major disadvantage of using chlorination for disinfection of water. (C) Addition of ammonia to water treated with chlorine leads to the formation of chloramines.
Which of the above statements are correct?

Correct option is C

Explanation
· Statement (a) is correct: Alum (aluminum sulfate) is indeed used as a coagulating agent in water treatment. It helps in the aggregation of particles, facilitating their removal during the sedimentation process.
· Statement (b) is incorrect: While residual chlorine can pose some concerns, such as taste and odor issues, it is not considered a major disadvantage of chlorination. In fact, residual chlorine is important for ensuring the continued disinfection of water during distribution, providing protection against microbial regrowth.
· Statement (c) is correct: The addition of ammonia to chlorinated water results in the formation of chloramines, which are used as a secondary disinfectant. Chloramines are less reactive and can provide longer-lasting disinfection in the distribution system.
Information Booster
· Coagulation Process: The coagulation process is essential for removing turbidity and pathogens, significantly improving water clarity and quality.
· Residual Chlorine: The presence of residual chlorine is crucial for maintaining disinfection throughout the water distribution system; however, it can react with organic matter to form disinfection byproducts (DBPs).
· Chloramines: Chloramines provide a more stable form of disinfection compared to free chlorine and are effective in controlling biofilm growth in distribution systems.
Additional Information
· Chlorination Methods: Different methods of chlorination (gas, liquid, or solid chlorine) may influence the levels of residual chlorine and the formation of chloramines.
· Water Treatment Goals: The primary goals of water treatment include removing contaminants, pathogens, and improving taste and odor.