A protein is present in 10,000L of fermentation liquor at a concentration of 0.5g/L. Ultrafiltration under gel polarization conditions is used to concentrate the protein. The gelation concentration is estimated as 25g/L. The filtration is carried out using a spiralwound module with a mass transfer coefficient of 2106m/s. The protein is rejected completely by the membrane and the effects of fouling are assumed to be negligible. a) If the membrane had a surface area of 200m2, how long would it take to concentrate the protein by a factor of 5 ? b) How long would it take to concentrate the protein by a factor of 10