Brewing Product Water Final Treatment SAQ

Question 1

What are the methods to remove iron from water?

Answer 1

Filtration after aeration and oxidation, reverse osmosis, cation exchange, phosphoric acid and precipitation/filtration.

Iron removal is essential for preventing staining and maintaining water quality.

Question 2

How can nitrates be removed from water?

Answer 2

Anion exchange or reverse osmosis.

Nitrate removal is important to prevent health hazards associated with high nitrate levels.

Question 3

What method is used to remove trihalomethanes (THM) from water?

Answer 3

Activated carbon filtration.

THMs are harmful byproducts of chlorination and need to be reduced for safe drinking water.

Question 4

What are the methods to remove chlorine from water?

Answer 4

Activated carbon filtration, UV degradation, and metabisulphite addition.

Removing chlorine is necessary to improve taste and eliminate potential harmful effects.

Question 5

What technology is used to remove bacteria from water?

Answer 5

Microfiltration (sterile filtration).

Microfiltration is effective in providing safe drinking water by removing pathogens.

Question 6

What is the principle of membrane filtration?

Answer 6

Utilises a semi-permeable membrane that allows water and certain ions to pass while retaining others based on size.

This principle is crucial for various water treatment processes.

Question 7

List the four main types of membrane filtration used in water treatment.

Answer 7

• Microfiltration (0.1 μm and 0.7-4 bar)
• Ultrafiltration (0.01 μm and 2-7 bar)
• Nanofiltration (0.001 μm and 6-10 bar)
• Reverse osmosis (0.0001 μm and 10 to 20 bar, up to 82 bar for seawater)

Each type has specific applications based on pore size and operating pressures.

Question 8

What is the main reason for using microfiltration?

Answer 8

Removes bacteria and yeast from water.

Microfiltration is critical for ensuring microbiological safety in drinking water.

Question 9

What is the principle of reverse osmosis?

Answer 9

Diffusion of water across a semi-permeable membrane from low to high solute concentration, requiring pressure to overcome osmotic pressure.

Reverse osmosis is widely used for desalination and producing high-purity water.

Question 10

How does a reverse osmosis plant work?

Answer 10

Feed water is pumped at high pressure, passing through the membrane, producing permeate (demineralised water) and reject (concentrate) streams.

This process is essential for efficient water treatment and minimizing waste.