Hazardous Waste Management Multiple Choice Questions on “Landfill Disposal – Design and Construction”.
1. Which of the following is the most important variable in the construction of soil liners?
a) Type of compaction
b) Permeability
c) Flammability
d) Ignitability
Answer: a
Clarification: Soil water content, type of compaction, compactive effort, size of soil clods are important variables in the construction of soil liners.
2. Excavation of soil in a location for liner is known as ________ pit.
a) Dig
b) Borrow
c) Barrow
d) Excavated
Answer: b
Clarification: Excavation of soil in a location for liner is known as borrow pit and excavated soil is referred to as borrow soil.
3. Bentonite is mixed when there is not enough clay available at a site to construct a soil liner.
a) True
b) False
Answer: a
Clarification: Bentonite is mixed when there is not enough clay available for liner, dry bentonite is mixed with the soil first, and water is added only after the mixing process is complete.
4. Which among the following is used as clay material for clay liner?
a) Kaolinite
b) Lead
c) Sulphur
d) Bromide
Answer: a
Clarification: Clay materials consists of varying proportions of hydrated aluminum silicates such as kaolinite, bentonite and montmorillonite.
5. What is the design permeability of the clay liner?
a) 10-8
b) 10-9
c) 10-10
d) 10-11
Answer: a
Clarification: The design permeability of the clay liner is 10-8 metre per second (m/s) and to avoid cracking of clay +4% wet of optimum moisture content is maintained.
6. PVC liners are suitable for landfills.
a) True
b) False
Answer: a
Clarification: Polyvinyl chloride (PVC) and high-density polyethylene (HDPE) liners are generally suitable for the landfill since they are flexible.
7. Drainage pipes of leachate collection system is filled with ________
a) Gravel
b) Dust
c) Clay
d) Grass
Answer: a
Clarification: The leachate collection system comprises a network of drainage pipes and is covered with a sand/gravel drainage layer.
8. What should be the slope percent between primary and secondary liners?
a) 1
b) 2
c) 3
d) 4
Answer: b
Clarification: 2% slope should be provided between primary and secondary liners with a slotting area of 100 cm2 per running meter of the pipe.
9. What is the formula for quantification of leachate generation from landfill?
a) I = P – P (CR/O) – AET +/- S
b) P = I – P (CR/O) – AET +/- S
c) I = S – P (CR/O) – AET +/- P
d) I = P – S (CR/O) – AET +/- Y
Answer: a
Clarification: I = P – P (CR/O) – AET +/- S where, I is Rate of Infiltration, P is Precipitation, CR/O is Coefficient of Runoff, AET is Actual Evapo-transpiration, S is Soil Moisture Content Retention Capacity.
10. The lateral leachate collection pipes shall slope towards ________ pipe.
a) Sump
b) Drain
c) Main
d) Longitude
Answer: c
Clarification: The lateral leachate collection pipes shall slope towards the main collection pipe and the main pipe shall slope towards the sump.
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