Determine the diameter and height of an air stripper designed to treat PCE from $18\mathrm{.}94\backslash$mu g$/$L to $1\mathrm{.}9\backslash$mu g$/$L with a stripping factor of $5$ using $25$mm Raschig rings and a pressure drop of $100$N$/$m$2/$m$.$ The full$$scale flow rate is $400$gpm$.$ Assume that the temperature of the water is $20\backslash$deg C$.$ Please explain why you that stripping factor is a good fit and answer the question?