In water purification system, fine sand and coarse gravel are present in the _________ tank which helps in the purification of water.
Question 9
In a filtration plant, water is filtered using layers of (a) sand and clay (b) clay and fine gravel (c) sand and fine gravel (d) sand, fine gravel and medium gravel
Which one of the following processes is used in the purification of water in a municipal water treatment system?