Dairy Processing Equipment

In reverse osmosis concentration of cheese whey, feed lactose concentration is $C_f = 50.0\text{ g/L}$ and permeate lactose concentration is $C_p = 1.0\text{ g/L}$. The apparent rejection coefficient $R = \left(1 - \frac{C_p}{C_f}\right) \times 100 = \left(1 - \frac{1.0}{50.0}\right) \times 100 = (1 - 0.02) \times 100$. The rejection $R$ in percentage is: