250+ TOP MCQs on Disposal by Land Treatment and Answers

Waste Water Engineering Multiple Choice Questions on “Disposal by Land Treatment”.

1. The wastewater disposed on land reaches groundwater and thereby contaminates surface water.
a) True
b) False
Answer: a
Clarification: Disposal onto land generally pollutes groundwater, and may reach surface water when groundwater eventually discharges into surface water. Disposal from an off-site treatment plant for groundwater recharge to control encroachment of seawater in coastal areas is a form of reuse.

2. What does LPED stand for?
a) Low plane effluent disposal
b) Low pressure effluent disposal
c) Low pressure effluent distribution
d) Low plane effluent distribution
Answer: c
Clarification: LPED stands for Low pressure effluent distribution. Effluent may be discharged more evenly across the disposal area by pump or dose loading. It also eliminates the chance of disposal surges that may occur during periods of high household use.

3. _______ is an improved sinkhole or a subsurface fluid distribution system.
a) Deep well
b) Injection well
c) Sink well
d) Bore well
Answer: b
Clarification: An injection well is a device that places fluid deep underground into porous rock formations, such as sandstone or limestone, or into or below the shallow soil layer. The fluid may be chemicals mixed with water, wastewater, etc.

4. Waste water is injected into the ground between impermeable layers of rocks to avoid polluting fresh water supplies.
a) True
b) False
Answer: a
Clarification: In waste water disposal, treated waste water is injected into the ground between impermeable layers of rocks to avoid polluting fresh water supplies or adversely affecting the quality of receiving waters.

5. _________ is the controlled application of waste water onto the land surface to achieve a specified level of treatment.
a) Water treatment
b) Wastewater treatment
c) Land treatment
d) Soil treatment
Answer: c
Clarification: The controlled application of waste water onto the land surface to achieve a specified level of treatment through natural physical, chemical, and biological processes within the plant soil-water matrix is called land treatment.

6. Which type of treatment methods are used for municipal and industrial wastewaters?
a) Slow rate
b) Rapid infiltration
c) Overflow
d) Main stream
Answer: a
Clarification: Slow Rate (SR) systems are the predominant form of land treatment for municipal and industrial waste-water. Such a technology incorporates waste-water treatment, water reuse, crop utilization of nutrients and waste-water disposal.

7. How are suspended solids removed from the soil?
a) Soil adsorption
b) Bacterial oxidation
c) Filtration
d) Chemical immobilization
Answer: c
Clarification: BOD is removed through soil adsorption and bacterial oxidation. Suspended solids are removed by filtration through the soil. Phosphorus is removed by chemical immobilization (precipitation and adsorption), plant uptake.

8. How are the traces of organic compounds removed from the soil?
a) Denitrification
b) Soil filtration
c) Precipitation
d) Sorption
Answer: d
Clarification: Nitrogen is removed by denitrification. The traces of organic compounds are removed by photodecomposition, volatilization, sorption, degradation. Metals are removed by precipitation.

9. Which of the following wastewater constituents are removed by chemical immobilization?
a) BOD
b) Suspended solids
c) Metals
d) Phosphorus
Answer: d
Clarification: Chemical immobilization is a process consisting of precipitation and adsorption. Phosphorus is removed by chemical immobilization and it is also removed by plant uptake. The plant utilizes phosphorus for various purposes.

10. Which of the following is an intensive method of land treatment?
a) Rapid infiltration
b) Infiltration
c) Slow rate
d) Over flow
Answer: a
Clarification: Rapid infiltration (RI) is the most intensive of all land treatment method. To shallow infiltration or spreading basins high hydraulic and organic loadings are applied intermittently.