Demineralization

Question 1

Mineral rejection is

Answer 1

The ability of the membrane to reject minerals

Question 2

Reverse osmosis, the water flux is dependent

Answer 2

On the applied pressure while the mineral flux isn’t

Question 3

Why is chlorine added to the feed water of an RO unit?

Answer 3

Prevent biological fouling

Question 4

If iron in the ferric form is found in the water

Answer 4

the unit will act as a filter

Question 5

To remove inorganic particles in RO MEMBRANE use

Answer 5

And acid flush or citric acid

Question 6

Optimal water characteristics for ion exchange (6)

Answer 6

1. Ph 6.5-9.0
2. NO3(nitrates) < 5mg/l
3. SO4(sulfate) < 50 mg/l
4. TDS total dissolved solids <500mg/l
5. Turbidity < 0.3 NTU
6. Total hardness < 350 mg/l

Question 7

(2) RO treatments

Answer 7

Cellulose acetate
thin film composite

Question 8

Hydrolysis rate for cellulose acetates membrane, in order to slow hydrolysis an acid is added

Answer 8

As pretreatment before demineralization

Question 9

Iron and manganese particles can plug

Answer 9

The filter media in stage 1

Question 10

Rinse stage, if rinse isnt sufficient

Answer 10

Salty taste will be noticed