A plasmid solution $($concentration $=0\mathrm{.}1\frac{g}{l})$ is being concentrated by ultrafiltration in a continuous manner using a using a tubular membrane module, which gives an apparent sieving coefficient of $0\mathrm{.}02.$ The feed flow rate into the membrane module is $800m\frac{l}{m}in$ and the average permeate flux obtained at the operating condition is $3{10}^{-5}\frac{m}{s}.$ If the membrane surface area is $0\mathrm{.}1m^2$ predict the concentration of the plasmid in the retentate stream. Assume that the permeate flux is same at all locations on the membrane and the concentration of the plasmid increases linearly within the membrane module.