This problem has three parts. This is part $1.$ An industry has a two$-$stage treatment process with a volumetric flow rate of $3,785$ m$3/$d$.$ The first stage is a bioreactor with a hydraulic detention time of $1$ day. The second stage is a treatment lagoon with an approximate hydraulic detention time of $10$ days. For a maximum specific rate of substrate utilization of $18$ mg BODL$/$mg VSSa$-$d$,$ half$-$saturation constant of $10$ mg BODL$/$L$,$ endogenous decay coefficient of $0\mathrm{.}25$ d$-1,$ true yield for cell synthesis of $0\mathrm{.}7$ mg VSSa$/$mg BODL, biodegradable fraction of $0\mathrm{.}90,$ input concentration of inert biomass of $40$ mg VSSi$/$L $($assume no active biomass influent$)$ and an influent substrate concentration of $1000$ mg BODL$/$L$.$ Calculate the total biological oxygen demand in the effluent, in mg BODL$/$L assuming the formation of soluble microbial products can be ignored.