A CSTR is used to treat an industrial waste, using a process that destroys the pollutant according to first-order kinetics, with a k = 0.126/day.

A CSTR is used to treat an industrial waste, using a process that destroys the pollutant according to first-order kinetics, with a k = 0.126/day. The reactor volume is

500 m3, the volumetric flow of the single inlet and exit is 50 m3/s, and the inlet pollutant concentration is 100 mg/L. Assuming steady-state conditions, what is the outlet

concentration after treatment? Do the mass balance.

I get a concentration of 99 mg/L, which doesn't seem correct. I think I messed up the units, but I can't tell where. Please show all steps.