A$4$MGD $(20,000$m$/$day$)$ of industrial wastewater having BODs concentration of $1000$my L$,$ and reaction rate of $4\mathrm{.}0/$day is generated by industries at a city's industrial park.Because of the high BOD, there is a plan to build an industrial pre$-$treatment system at an industrial park. Effluent from the pre$-$treatment will be discharged into the city sewer for final polishing at the city wastewater treatment plant. Determine percent BODs removal if the wastewater is treated in two continuous flow stirred tank reactors in parallel with equal flow to each reactor having a volume of $2500$m$*?$