Civil Engineering MCQ – Waste Water Engineering

Waste Water Engineering MCQ questions and answers are accessible to aid Civil Engineering students in preparing for GATE exams, technical interviews, competitive examinations, and other entrance exams. The Waste Water Engineering MCQ section is a crucial topic for both Civil Engineering and GATE aspirants.

1. What is the primary goal of wastewater engineering?

a) To create new water sources
b) To transport wastewater for disposal
c) To treat and clean wastewater before it is released back into the environment
d) To increase wastewater production

Answer:

c) To treat and clean wastewater before it is released back into the environment

Explanation:

Wastewater engineering focuses on the treatment and purification of wastewater to make it suitable for discharge back into the environment or for reuse, ensuring it doesn't harm the ecosystem or public health.

2. What is a common method for treating wastewater?

a) Filtration
b) Boiling
c) Freezing
d) Electrolysis

Answer:

a) Filtration

Explanation:

Filtration is a common method in wastewater treatment, where physical barriers are used to remove solids, bacteria, and other impurities from the water.

3. What is the purpose of aeration in wastewater treatment?

a) To cool down the water
b) To remove color from the water
c) To increase the oxygen content in the water
d) To heat the water

Answer:

c) To increase the oxygen content in the water

Explanation:

Aeration in wastewater treatment is the process of increasing the oxygen saturation of the water, which is essential for the biological treatment processes that break down organic matter.

4. What does BOD stand for in wastewater engineering?

a) Biological Oxygen Demand
b) Biochemical Organism Density
c) Bacterial Oxygen Detoxification
d) Biologic Ozone Distribution

Answer:

a) Biological Oxygen Demand

Explanation:

BOD, or Biological Oxygen Demand, is a measure of the quantity of oxygen used by microorganisms in the oxidation of organic matter in water. It is an important parameter in assessing water quality.

5. What is primary treatment in wastewater engineering?

a) The first stage of wastewater treatment, focusing on removing solid materials
b) The final stage of wastewater treatment
c) The treatment of drinking water
d) The process of desalination

Answer:

a) The first stage of wastewater treatment, focusing on removing solid materials

Explanation:

Primary treatment is the first stage of wastewater treatment. It involves the removal of large solids and floating materials through physical processes like screening and sedimentation.

6. What is sludge in the context of wastewater engineering?

a) Clean drinking water
b) A solid byproduct from the wastewater treatment process
c) A type of chemical used in water treatment
d) The initial raw wastewater

Answer:

b) A solid byproduct from the wastewater treatment process

Explanation:

Sludge is the semi-solid byproduct that is produced during the treatment of wastewater. It contains a significant amount of water along with various organic and inorganic materials.

7. In wastewater engineering, what is effluent?

a) Untreated wastewater
b) The output stream of treated water from a wastewater treatment plant
c) The machinery used in wastewater treatment
d) A toxic gas released during treatment

Answer:

b) The output stream of treated water from a wastewater treatment plant

Explanation:

Effluent in wastewater engineering refers to the treated water that is discharged from a wastewater treatment plant after it has undergone various treatment processes.

8. What role do microorganisms play in wastewater treatment?

a) They are harmful and must be removed
b) They help in the breakdown of organic matter in the water
c) They increase the BOD levels
d) They are used for coloring the water

Answer:

b) They help in the breakdown of organic matter in the water

Explanation:

Microorganisms play a crucial role in wastewater treatment, particularly in the biological treatment stages, where they break down organic matter, reducing BOD and removing harmful substances.

9. What is secondary treatment in wastewater engineering?

a) The addition of chemicals to the water
b) The removal of dissolved organic matter and further reduction of solids
c) The first stage of water treatment
d) The process of water aeration

Answer:

b) The removal of dissolved organic matter and further reduction of solids

Explanation:

Secondary treatment is a biological process that follows primary treatment. It involves the further reduction of organic matter and suspended solids, often through microbial action.

10. Why is disinfection important in wastewater treatment?

a) To increase the water temperature
b) To remove all minerals from the water
c) To kill or deactivate pathogenic microorganisms
d) To change the water's color

Answer:

c) To kill or deactivate pathogenic microorganisms

Explanation:

Disinfection is a critical step in wastewater treatment as it kills or deactivates harmful pathogens and bacteria, making the water safe for discharge or reuse.

11. What is tertiary treatment in wastewater engineering?

a) The initial phase of wastewater treatment
b) A specialized treatment process to remove specific contaminants
c) The process of increasing water pH
d) The method of cooling treated water

Answer:

b) A specialized treatment process to remove specific contaminants

Explanation:

Tertiary treatment is an advanced cleaning process in wastewater treatment that follows primary and secondary treatment, focusing on the removal of specific contaminants like phosphorus, nitrogen, and certain organic compounds to meet specific water quality standards.

12. What is the purpose of a sedimentation tank in wastewater treatment?

a) To aerate the water
b) To allow solid particles to settle out from the wastewater
c) To increase the temperature of the water
d) To store treated water

Answer:

b) To allow solid particles to settle out from the wastewater

Explanation:

A sedimentation tank in wastewater treatment is designed to hold wastewater for a period, allowing heavy solid particles to settle to the bottom, facilitating their removal.

13. What does the term 'greywater' refer to?

a) Wastewater that is high in industrial pollutants
b) Untreated wastewater from toilets
c) Wastewater from baths, sinks, and other domestic sources excluding toilets
d) Rainwater collected for reuse

Answer:

c) Wastewater from baths, sinks, and other domestic sources excluding toilets

Explanation:

Greywater is relatively clean wastewater from domestic activities such as laundry, dishwashing, and bathing, which can be recycled on-site for uses such as landscape irrigation and constructed wetlands.

14. What is the significance of a grit chamber in a wastewater treatment plant?

a) To remove organic matter from wastewater
b) To add necessary nutrients to the water
c) To remove sand, silt, and small stones from wastewater
d) To heat the wastewater

Answer:

c) To remove sand, silt, and small stones from wastewater

Explanation:

A grit chamber is an integral part of the preliminary treatment in a wastewater treatment plant, designed to remove heavier inorganic materials like sand, silt, and small stones which could damage equipment or hinder further treatment processes.

15. What role does activated sludge play in wastewater treatment?

a) It's a chemical added to increase water pH
b) It's a byproduct used for land fertilization
c) It's a biological mass of microorganisms used to degrade organic pollutants
d) It's a solid residue that needs to be disposed of immediately

Answer:

c) It's a biological mass of microorganisms used to degrade organic pollutants

Explanation:

Activated sludge is a type of biological treatment where a mix of microorganisms in aeration tanks is used to break down organic pollutants in wastewater, forming part of the secondary treatment process.

16. What is an oxidation pond used for in wastewater treatment?

a) To store clean drinking water
b) To increase water temperature through solar radiation
c) To treat wastewater through natural processes involving algae and bacteria
d) To evaporate wastewater completely

Answer:

c) To treat wastewater through natural processes involving algae and bacteria

Explanation:

Oxidation ponds, also known as lagoons, are large, shallow ponds designed to treat wastewater through the combined action of sunlight, bacteria, and algae, a natural and cost-effective method of treatment.

17. Why is phosphorus removal important in wastewater treatment?

a) To prevent eutrophication in receiving water bodies
b) To increase the hardness of water
c) To make the water taste better
d) To change the color of the water

Answer:

a) To prevent eutrophication in receiving water bodies

Explanation:

Removing phosphorus from wastewater is crucial to prevent eutrophication, a process where excessive nutrients in water bodies lead to excessive plant growth and oxygen depletion, harming aquatic life.

18. What is the purpose of a clarifier in a wastewater treatment plant?

a) To clarify the goals of the treatment process
b) To mix chemicals into the wastewater
c) To separate solid waste from the liquid
d) To add flavor to the treated water

Answer:

c) To separate solid waste from the liquid

Explanation:

A clarifier in wastewater treatment is a tank where solid waste particles settle to the bottom and clarified water passes over weirs for further treatment or discharge, aiding in the solid-liquid separation process.

19. How is ultraviolet light used in wastewater treatment?

a) To change the color of the water
b) To heat the water
c) As a disinfection method to kill harmful microorganisms
d) To increase water acidity

Answer:

c) As a disinfection method to kill harmful microorganisms

Explanation:

Ultraviolet (UV) light is used in the disinfection stage of wastewater treatment to kill or deactivate harmful microorganisms by damaging their DNA, a chemical-free method of disinfection.

20. What is the primary purpose of a septic tank in domestic wastewater treatment?

a) To store drinking water
b) To collect and treat sewage from individual homes
c) To heat wastewater
d) To transport wastewater to treatment plants

Answer:

b) To collect and treat sewage from individual homes

Explanation:

A septic tank is an underground chamber used in domestic wastewater management, where sewage is collected and allowed to decompose through bacterial activity before draining by means of a leaching field.

21. What is a water reclamation facility?

a) A plant that increases water salinity
b) A facility that treats wastewater to make it reusable
c) A plant for desalination of seawater
d) A facility for storing rainwater

Answer:

b) A facility that treats wastewater to make it reusable

Explanation:

A water reclamation facility treats wastewater to a high standard so that it can be reused for various purposes, such as irrigation, industrial processes, or replenishing groundwater, conserving fresh water resources.

22. In wastewater engineering, what is the importance of the nitrification process?

a) To remove oxygen from water
b) To convert ammonia in wastewater into nitrates
c) To increase water temperature
d) To decrease the pH of water

Answer:

b) To convert ammonia in wastewater into nitrates

Explanation:

Nitrification is a crucial biological process in wastewater treatment where ammonia is oxidized to nitrite and then to nitrate, reducing the toxicity of the effluent and preventing eutrophication.

23. What does the term 'effluent standards' refer to?

a) The color standards for treated water
b) The temperature levels of effluent
c) The regulatory limits on pollutants in treated wastewater
d) The standard volume of effluent produced

Answer:

c) The regulatory limits on pollutants in treated wastewater

Explanation:

Effluent standards are regulations that set the maximum allowable levels of pollutants in effluent discharged from wastewater treatment plants, ensuring environmental protection and public health.

24. Why is anaerobic digestion used in wastewater treatment?

a) To add nutrients to the water
b) To remove all minerals from wastewater
c) To break down organic matter in sludge and produce biogas
d) To increase the alkalinity of water

Answer:

c) To break down organic matter in sludge and produce biogas

Explanation:

Anaerobic digestion is a process used in wastewater treatment to decompose organic matter in sludge in the absence of oxygen, reducing sludge volume and producing biogas, which can be used as an energy source.

25. What is the significance of a stormwater detention basin in urban wastewater management?

a) To store potable water for cities
b) To provide recreational space for urban areas
c) To temporarily hold stormwater and release it slowly to prevent flooding
d) To generate hydroelectric power

Answer:

c) To temporarily hold stormwater and release it slowly to prevent flooding

Explanation:

Stormwater detention basins are designed to capture and temporarily store stormwater runoff during heavy rains and release it slowly into the drainage system, preventing flooding and erosion in urban areas.

Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top