250+ TOP MCQs on Physical Treatment – Evaporation and Answers

Hazardous Waste Management Multiple Choice Questions on “Physical Treatment – Evaporation”.

1. Rate of evaporation of liquid waste is measured by _______
a) Vapour pressure
b) Pressure
c) Temperature
d) Heat
Answer: a
Clarification: Rate of evaporation of liquid waste is measured by vapour pressure which is a measurement of volatility of liquid.

2. Liquids with high vapour pressure evaporates slowly.
a) True
b) False
Answer: b
Clarification: Liquids with high vapour pressure evaporates readily while those with low vapour pressure evaporates slowly.

3. __________ separation techniques are used before evaporation process.
a) Physical
b) Chemical
c) Biological
d) Biochemical
Answer: a
Clarification: Physical separation techniques are used before evaporation process since it reduces solids formation and maintains high heat transfer efficiencies.

4. The residues produced from evaporation treatment is _________
a) Less
b) More
c) Undetermined
d) No residue
Answer: a
Clarification: Evaporation produces concentrated liquor with less residues and the volume of water that must be treated or disposed is reduced.

5. Evaporation of liquids from hazardous waste through multiple evaporator, distillation etc. is dependent on ________
a) Melting point
b) Freezing point
c) Boiling point
d) Vapour pressure
Answer: c
Clarification: Evaporation of liquids from hazardous waste through single, multiple evaporator, distillation, air stripping evaporators use steel tubes to heat liquid waste to the boiling point.

6. Steel tubes used in multiple effect evaporator are placed on surface.
a) True
b) False
Answer: b
Clarification: Steel tubes used in multiple effect evaporator are submerged in liquid to maximise heat transfer and promote efficient evaporation.

7. Evaporator must have sufficient disc engaging space to achieve ________
a) Separation
b) Chemicals
c) Boiling
d) Pressure
Answer: a
Clarification: Evaporator must have sufficient disc engaging space to achieve separation between the distillate and liquid blown solution.

8. Which of the following waste is not applicable for evaporation?
a) Calcium
b) Iron
c) Copper
d) Methylene chloride
Answer: d
Clarification: Wastes containing organic constituents, such as methylene chloride, solvents, oils, petroleum products etc. are not suitable for use in the evaporation system.

9. _________ wastes can be treated in evaporator.
a) Aqueous inorganic
b) Organic
c) Aqueous organic
d) Dry
Answer: a
Clarification: Only aqueous inorganic wastes can be treated in an evaporator such as caustics, rinse waters, metal sludge, and water-based machining coolants.

10. Evaporation units may be operated without obtaining a permit if ________
a) Chemicals are used
b) Resins are associated
c) Unit is enclosed
d) Waste is reused
Answer: c
Clarification: Evaporation units may be operated without obtaining a permit if evaporation unit meets the definition of a totally enclosed treatment system in 40 CFR 260.10.

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