Casein is to be washed, in a multistage system, by water. The casein curd has initially a water content of 60% and between stages it is drained on an inclined screen to 80% water (both on a wet basis). The initial lactose content of the casein is 4.5 % on a wet basis, and it is necessary to produce casein with a lactose content of less than 1% on a dry basis. How many washing steps would be needed if the wet casein is washed with twice its own weight of fresh water in each step?

A feed solution with a solute concentration of 3 % by weight is treated by reverse osmosis. The permeate contains 150 ppm of solute (ppm = parts per million). Calculate the retention (R) and the separation factor (α). Explain which of the two parameters is more suitable for this application.

To increase their shelf life and enhance their flavour, harvested tea leaves are processedthrough a drying process. Consider that picked tea leaves consist only of solid and water, with amoisture mass content of 60%. Commercial demand requires producing 160kg/hr with areduced moisture content of 5%.Determine the mass rate of water removed in the drying process

o increase their shelf life and enhance their flavour, harvested tea leaves are processedthrough a drying process. Consider that picked tea leaves consist only of solid and water, with amoisture mass content of 60%. Commercial demand requires producing 160kg/hr with areduced moisture content of 5%.Determine the mass rate of water removed in the drying process.