A $2 \: \mathrm{L}$ bioreactor is being operated as a chemostat, at a flow rate of $0.8 \: \mathrm{~L} / \mathrm{h}$ and sterile feed of $10 \: \mathrm{~g} / \mathrm{L}$ substrate. The bacterial growth follows Monod kinetics at a maximum specific growth rate of $0.6 \: \mathrm{~h}^{-1}$ with a Monod constant of $0.5 \: \mathrm{~g} / \mathrm{L}$ and a biomass yield coefficient of $0.4 \: \mathrm{~g} / \mathrm{g}$.
The exit biomass concentration is $\_\_\_\_\_ \: \mathrm{g/L}$
(Round off to one decimal place)
