Tough Waste Water Engineering Questions and Answers on “Ion Exchange Media Properties – 2”.
1. What is the SAC resin made up of?
a) Styrene and vinyl benzene
b) Divinyl benzene
c) Benzene and styrene
d) Styrene and divinyl benzene
Answer: d
Clarification: The SAC resin is made up of styrene and divinyl benzene. The functional group is sulphonic acid. These resins maybe gel or macro porous in nature.
2. In a SAC resin, what is the preferred cross linking?
a) 6-8%
b) 8-10%
c) 10-12%
d) 12-14%
Answer: a
Clarification: Usually SAC resins with 6-8% cross-linking divinyl benzene is used. This resin is used to remove alkalinity, EMA and CO2. In case of no degassed this is used to remove CO2.
3. What is the WAC resin made up of?
a) Polyacrylic acid
b) Polyacrylic acid with a carboxylic acid functional group
c) Acrylic acid with a carboxylic acid functional group
d) Acrylic acid
Answer: b
Clarification: The WAC resin constitutes the Polyacrylic acid with a carboxylic acid functional group. This resin removes alkalinity. This resin also removes hardness.
4. Which type of character does the strong basic acid type I have?
a) High basicity
b) Low basicity
c) High boiling point
d) Low boiling point
Answer: a
Clarification: The strong basic acid type I has high overall basicity. Therefore this gives good effluent quality. Indian FFIP is a type of type I SBA.
5. Which type of character does the strong basic acid type II have?
a) High basicity
b) Low basicity
c) High boiling point
d) Low boiling point
Answer: b
Clarification: The strong basic acid type II has low basicity. Therefore this requires more caustic acid for regeneration. Indian NIP is a type of strong basic acid type II.
6. For which type of pollutant contained in water the macro porous type of weak basic acid is used?
a) Organic contaminant
b) Inorganic contaminant
c) Heavy metals
d) Monochromic ions
Answer: a
Clarification: To remove organic content macro porous weak base anion resin is used. Weak basic acids can be regenerated with stoichiometric regenerated. For treatment of waters which do not provide organic fouling gel type is used.
7. Which of these is not a characteristic for coarse particle sized resins?
a) Poor rate of exchange
b) More attrition loss
c) Low pressure drop
d) Good backwash expansion
Answer: d
Clarification: Coarse particle sized resins have a poor rate of exchange. These have high attrition loss. They don’t have a good backwash expansion.
8. What is the uniform coefficient of resin?
a) Ratio of 40% retained to ratio of 90% retained
b) Ratio of 40% retained to ratio of 70% retained
c) Ratio of 40% retained to ratio of 80% retained
d) Ratio of 30% retained to ratio of 90% retained
Answer: a
Clarification: Ratio of 40% retained to ratio of 90% retained is defined as a uniform coefficient. Effective size is defined as the screen opening that will retain 90% of the screenings. Particle size distribution is determined by sieve analysis.
9. What is the specific gravity of anion resin?
a) 1.05-1.115
b) 4.4-7.3
c) 1.15-1.23
d) 1.23-1.56
Answer: a
Clarification: The specific gravity of anion resin is 1.05-1.115. Cations are denser than anions. The density of cation resins are 1.2-1.3 gm.
10. What is the surface area of the gel resin?
a) 0.01m2/gm
b) 0.5 m2/gm
c) 1-2m2/gm
d) 2-4 m2/gm
Answer: a
Clarification: The surface area of the gel resin is 0.01 m2/gm. The surface area is extremely negligible. Macro porous resins have larger areas.
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