In a water treatment plant, 'Plain sedimentation' process is used for removing
- Afloating matters such as leaves, dead animals
- Bsilt, sand and clayCorrect
- Cfine suspended solids
- Ddissolved solids
Solution
Concept
Sedimentation without coagulants
Step-by-step solution
1. Plain sedimentation removes the heavier suspended particles (silt, sand and clay) that settle under gravity. 2. Fine suspended solids and colloids need coagulation; dissolved solids need other processes.
Explanation
Settling without chemicals works for settleable particles.
Why the other options are wrong
Floating matter is removed by screens; dissolved solids are not removed by settling.
Shortcut
Plain sedimentation → silt and sand.
Correct answer: B) silt, sand and clay