Question $12$ a

Outine below is the sequence of unit operations and chemical additions used in the treatment of

reservoir water supply. Briefly state the function or purpose of each unit process and the reason

for each chemical addition.

$($i$)$ Intermittent application of copper sulfate to reservoir during summer and fall

$($ii$)$ Chlorine dioxide available when needed

$($iii$)$ Mixing and flocculation with addition of alum and polymer

$($iv$)$ Sedimentation

$($v$)$ Addition of activated carbon

$($vi$)$ Granular media filtration

$($vii$)$ Post chlorination