The process in a water treatment plant:
Before water is purified, it is pumped through coarse screens made of metal bars
that catches large objects like bottles and cans. The screened water is then forced into a mixing tank by the pumps.
In the mixing tank, chemical called coagulants are mixed into the water. Sticky clumps called flocs, that are aluminum hydroxide, are formed when the coagulants combine with bacteria, mud, and silt. Coagulants such as chlorine are added to kill bacteria and viruses.
As the water slowly passes into deep, broad sedimentation tanks the aluminum hydroxide sett…
