$1.$ Determine the overall removal efficiency for a sedimentation basin with a design over flowrate of $2$

m

$3$

$/$m$2$

$-$h in treating a natural water containing particles whose settling velocities are distributed as

given in the table below. Plot the particle histogram for the influent and effluent.

Settling velocity, m$/$h Number of particles per liter x $10-5$

$0\mathrm{.}0-0\mathrm{.}5$

$0\mathrm{.}5-1\mathrm{.}0$

$1\mathrm{.}0-1\mathrm{.}5$

$1\mathrm{.}5-2\mathrm{.}0$

$2\mathrm{.}0-2\mathrm{.}5$

$2\mathrm{.}5-3\mathrm{.}0$

$3\mathrm{.}0-3\mathrm{.}5$

$3\mathrm{.}5-4\mathrm{.}0$

total

$60$

$100$

$180$

$220$

$200$

$140$

$60$

$40$

$1000$