1. On which of the following does the self purification process does not depend?
a) Volume
b) Flow rate
c) Temperature
d) Aquatic species
Explanation: The speed and completeness of the self purification process depend upon many factors like volume, flow rate, the turbulence of flow, variation in sunlight, etc. Aquatic species are affected by polluted streams.
2. Flowing water bodies recover rapidly.
a) True
b) False
Explanation: Flowing water bodies like streams, canals and rivers can recover rapidly from degradable, oxygen demanding wastes and excess heat through a combination of dilution and bacterial decay.
3. In a flowing stream, the breakdown of degradable wastes by bacteria ________ dissolved oxygen.
a) Increases
b) Depletes
c) Maintains
d) Improves
Explanation: In a flowing stream, the breakdown of degradable wastes by bacteria depletes dissolved oxygen. This eliminates the populations with high oxygen requirements until the stream is cleansed of wastes
4. What is the objective of water quality management?
a) Control the discharge of pollutants
b) Pollutants are discharged into flowing streams
c) Selective pollutants are released
d) Only highly toxic pollutants are released
Explanation: To control the discharge of pollutants so that the water quality is not degraded to an unacceptable extent below the natural background level is the objective of water quality management.
5.The impact of pollution depends upon nature of the pollutants and the ___________
a) Toxic contaminants
b) Season
c) Contaminants
d) Characteristics of river
Explanation: The impact of pollution depends upon nature of the pollutants and the characteristics of the river like discharge and speed of flowing water, depth of the river, type of bottom, surrounding vegetation, etc.
6. Separation is a unit operation.
a) True
b) False
Explanation: In chemical engineering and related fields, a unit operation is a basic step in a process. Unit operations involve a physical change or chemical transformation such as separation, crystallization, evaporation, filtration, polymerization, isomerization, and other reactions.
7. Refrigeration is a mass transfer process.
a) True
b) False
Explanation: Processes like gas liquefaction and refrigeration are thermodynamic processes. Mass transfer processes include gas absorption, distillation, extraction, adsorption and drying
8. Solids concentration will be ________ in water than wastewater.
a) More
b) Less
c) Equal to
d) Similar
Explanation: Water and waste water differ only in the way that solids concentration will be more in waste water. Straining the finer particles in water treatment is called filtration and is towards the biological action of bacteria on the trickling filter to remove organic solids.
9. Unit operations are the ______ operations to remove the impurities.
a) Physical
b) Chemical
c) Biological
d) Biochemical
Explanation: The physical operations to remove the impurities present in the water and waste water are called unit operations where as the unit processes are the chemical and biological conversion on the status of the impurities that they will be converted to a form that can be easily separated.
10. What did the structures use to prevent floating matter that enters into pumps and pumping systems?
a) Aeration units
b) Screens
c) Grit chamber
d) Bioreactor
Explanation: Screens are in use from the intake structure where they prevent the floating matter enters into the pumping units, and fine and coarse screens are in use to treat waste water to prevent the entry of floating wastes and coarse solids into the treatment.