A settling basin is designed to have a surface overflow rate of $32\mathrm{.}6m{d}^{-1}.$ The basin treats a suspension of particles with the size distribution given below. The specific gravity of the particles is $1\mathrm{.}2$ and the water temperature is $20C$ at which dynamic viscosity is $1\mathrm{.}027$ centipoise and the density is $0\mathrm{.}997gc{m}^{-3}.$ Determine the removal efficiency for particles greater than $0\mathrm{.}07mm$ in size and also the overall removal efficiency for the entire suspension.

$(4$ marks$)$

$\backslash$table$[[$Particle size $(mm),0\mathrm{.}1,0\mathrm{.}08,0\mathrm{.}07,0\mathrm{.}06,0\mathrm{.}04,0\mathrm{.}02,0\mathrm{.}01],[\backslash$table$[[$Weight fraction greater$],[$than size $($per cent$)]],10,15,40,70,93,99,100]]$