A three$-$stage rotating biocontactor system is to be designed to treat a wastewater flow of $0\mathrm{.}1$

MGD with a strength of $250$ mg$/$L BOD$5.$ A treatability study revealed a P $=2500$ mg$/$ft$2$day and

a Ks $=100$ mg$/$L$.$ Compute the area requirements if an effluent having a BOD$5$ of $15$ mg$/$L is

desired. hint First you want to derive an equation for the effluent substrate concentration $($refer to slide $13).$ Then use trial and error method for A$.$ For the first attempt, try A$=35000$ ft$2($for your time saving$).$