Environmental Engineering Multiple Choice Questions on “Zeolite Process”.
1. In which process of water softening, ion exchange phenomenon takes place?
a) Lime soda process
b) Zeolite process
c) Boiling
d) Demineralization process
Answer: b
Clarification: In the zeolite process, calcium and magnesium are removed from hard water by ion exchange phenomenon.
2. In which process of water softening, the chemicals are added to remove hardness from water?
a) Lime soda process
b) Zeolite process
c) Boiling
d) Demineralization process
Answer: a
Clarification: In the Lime soda process, lime and soda are added to remove temporary and permanent hardness from water.
3. Zeolites are complex compound of ____________
a) Aluminium and lime
b) Silica and soda
c) Aluminium, silica and soda
d) Lime and soda
Answer: c
Clarification: Zeolites are complex compound of Aluminium, silica and soda. It has the property of removing calcium and magnesium from water and substituting sodium in their place.
4. The color of the artificial zeolite permutit is ____________
a) Grey
b) Yellow
c) Green
d) White
Answer: d
Clarification: The artificial zeolite permutit has a large and lustrous grain. They are white in color and has an appearance of coarse sand.
5. Natural zeolite is mainly processed from ____________
a) White sand
b) Green sand
c) Grey sand
d) Red sand
Answer: b
Clarification: The natural zeolite is mainly processed from Green sand, which is also called as Glauconite. It has lesser exchange value than artificial zeolite.
6. The color of the natural zeolite is ____________
a) Green
b) Grey
c) Black
d) Blue
Answer: a
Clarification: The color of the natural zeolite is green as it is processed from Glauconite which is green in color. It has an exchange value of 6500-9000gm of hardness per m3 of zeolite.
7. The chemical formula of Permutit is ____________
a) SiOAl2O3Na2O
b) SiO2Al2O3Na2O
c) SiO2Al2O3NaO
d) SiO3Al2O3Na2O
Answer: b
Clarification: The chemical formula of Permutit is SiO2Al2O3Na2O. The increase in the value of SiO2 increases its resistance to aggressive attacks.
8. Permutit has an exchange value of ________ grams of hardness per m3 of zeolite.
a) 10,000
b) 20,000-30,000
c) 35,000-40,000
d) 40,000-50,000
Answer: c
Clarification: Permutit has an exchange value of 35,000-40,000 grams of hardness per m3 of zeolite. They absorb moisture from the atmosphere and should be kept in a dry place.
9. The thickness of the layers of filter sand of zeolite softener is ____________
a) 20cm
b) 30cm
c) 40cm
d) 100cm
Answer: d
Clarification: The thickness of the layers of filter sand of zeolite softener lies in the range of 75 to 150cm and their functioning is similar to the rapid sand filter.
10. Which of the following is a disadvantage of the zeolite process?
a) No sludge is formed
b) The process is almost automatic
c) Suspended impurities get deposited around the zeolite particles
d) Zero hardness can be occurred
Answer: c
Clarification: The zeolite process is unsuitable for highly turbid water where suspended impurities get deposited around the zeolite particles.
11. The zeolite process is unsuitable for water containing iron and manganese.
a) True
b) False
Answer: a
Clarification: Iron and manganese bearing water deposit hydroxides on the surface of zeolite or react with zeolite to substitute iron and manganese for sodium, which is an irreversible reaction. This makes the zeolite process unsuitable.