Environmental/Civil Engineering Question When chemicals are added to water for coagulation, they are flash-mixed. Is there an advantage to this or would prolonged slow stirring accomplish the same purpose? Solution YES there is advantage of adding the chemical When we add the coagulent in water due to sticky nature they accumulate the suspended particles of small size and form large and heavy particle .These large partical of solid due to heavy weight settle down easily and time of filteration process got reduced by reducing settling time. and stirring /mixing is done to provide more apportunity of contact between coagulent and solid so that particle\'s size is increase more..

1. Environmental/Civil Engineering Question
When chemicals are added to water for coagulation, they are flash-mixed. Is there an advantage
to this or would prolonged slow stirring accomplish the same purpose?
Solution
YES
there is advantage of adding the chemical
When we add the coagulent in water due to sticky nature they accumulate the suspended
particles of small size and form large and heavy particle .These large partical of solid due to
heavy weight settle down easily and time of filteration process got reduced by reducing settling
time.
and stirring /mixing is done to provide more apportunity of contact between coagulent and solid
so that particle's size is increase more.