Ultrafiltration

Ultrafiltration is a type of filtration. Industries such as chemical and pharmaceutical manufacturing, food and beverage processing, and waste water treatment, employ ultrafiltration in order to recycle flow or add value to later products. Ultrafiltration is commonly abbreviated to "UF."

UF's main attraction is its ability to purify, separate, and concentrate target macromolecules in continuous systems. UF does this by pressurizing the solution flow. The solvent and other dissolved components that pass through the membrane are known as permeate. The components that do not pass through are known as retentate. Depending on the Molecular Weight Cut Off (MWCO) of the membrane used, macromolecules may be purified, separated, or concentrated in either fraction.

Currently, the study of UF processing occurs mainly in laboratory setups because it is very prone to membrane fouling caused by increased solute concentration at the membrane surface (either by macromolecular adsorption to internal pore structure of membrane, or aggregation of protein deposit on surface of membrane), which leads to concentration polarization (CP)). CP is the major culprit in decreasing permeate flux. Ultrafiltration is used as a pre-treatment step in reverse osmosis processes in many Middle Eastern countries to potable drinking water, as there is little fresh water available in thoseareas.

4. Answer the questions:

1. What is ultrafiltration?

2. Where is ultrafiltration employed and what for?

3. What is UF's main attraction?

4. What components do we call permeate (and retentate)?

5. What do macromolecules purification and separation de-pend on?

6. Why does UF processing mainly occur in laboratory setups?

7. Where is ultrafiltration used as a pre-treatment step?

8. What is CP?

5. Complete the following sentences using some active words and word combinations (see below):

1. Industries such as … employ ultrafiltration.

2. Ultrafiltration is employed in order … to later products.

3. The components that do not pass through the membrane are known as ….

4. There is a great solute … at the membrane surface.

5. Concentration polarization is the major … in decreasing permeate flux.

6. Ultrafiltration is used as a … step in many Middle Eastern countries.

chemical and pharmaceutical manufacturing, to add value, retentate, concentration, culprit, pretreatment.

6. Retell the text using the following scheme:

1. The headline of the text is…

2. The text informs on (deals with, dwells upon)…

3. At the beginning the author makes close study of

4. Then much attention is given to…

5. The text also tells about…

6. To sum up it should be noted…

Дата добавления: 2014-10-17