A fixed$-$bed adsorption system with an empty bed contact time of $12$ min, a superficial velocity of $8$ m$/$h$,$

and a density of $450$ kg$/$m$3$ is used to treat water with $650\backslash$mu g$/$L of Trichloroethene. For a plant capacity

of $20$ ML$/$d$,$ how long will this fixed bed last before it has to be replaced? How much volume of water can

be treated by the bed before it has to be replaced? For Trichloroethene, K$^$b$=55\mathrm{.}9,1/$n $=0\mathrm{.}48$