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?
1
(a) and (b) only
2
(b) and (c) only
3
(a) and (c) only
4
(a), (b) and (c) only