Water Supply and Wastewater Engineering MCQs (Part-5)
What is the primary purpose of coagulation in water treatment?
A Bind particles
B Filter water
C Raise pH
D Remove bacteria
Coagulation is the process where chemicals are added to bind fine particles in water, causing them to clump together into larger particles called flocs. These can then be removed by sedimentation or filtration.
Which process is commonly used to disinfect drinking water?
A Sedimentation
B Reverse osmosis
C Chlorination
D Filtration
Chlorination involves adding chlorine to water to kill or inactivate harmful microorganisms such as bacteria, viruses, and parasites, ensuring the water is safe for human consumption.
What is reverse osmosis primarily used for?
A Sedimentation
B Filtration
C Aeration
D Desalination
Reverse osmosis is mainly used for desalination, which is the process of removing salts and other impurities from seawater or brackish water, making it suitable for drinking and agricultural use.
What is the main objective of sedimentation in water treatment?
A Remove bacteria
B Remove large solids
C Raise pH
D Disinfect water
Sedimentation allows larger solids to settle at the bottom of a tank due to gravity. This process is vital in water treatment to reduce turbidity and prepare the water for further treatment like filtration.
What is the primary function of a wastewater collection system?
A Treat wastewater
B Store water
C Pump wastewater
D Transport wastewater
A wastewater collection system is responsible for transporting sewage from households and industries to treatment plants. It helps prevent the contamination of the environment and ensures safe disposal or treatment of wastewater.
What is the purpose of flocculation in water treatment?
A Add chemicals
B Bind larger particles
C Remove bacteria
D Clarify water
Flocculation is the process following coagulation, where the formed flocs are gently mixed to encourage further clumping of smaller particles. This increases the size of the particles for easier removal in sedimentation or filtration.
What type of water does desalination treat?
A Groundwater
B Wastewater
C Seawater
D River water
Desalination is used to treat seawater, removing salts and other impurities, making it suitable for drinking and agricultural use. This process is particularly essential in areas with limited freshwater resources.
What is the main purpose of a septic system?
A Treat wastewater
B Pump water
C Filter rainwater
D Distribute water
A septic system is used to treat wastewater on‐site, typically in rural areas. It processes waste by settling solids in a tank and using soil‐based filtration to safely dispose of the effluent.
What is a key feature of water filtration?
A Removes solids
B Removes bacteria
C Removes gases
D Adds minerals
Water filtration is designed to remove suspended solids, dirt, and debris from water. This is an essential step in water treatment to improve clarity and prepare the water for further treatment processes like disinfection.
What does a combined sewer system carry?
A Only industrial waste
B Both stormwater and sewage
C Stormwater only
D Sewage only
A combined sewer system carries both stormwater and sewage in the same pipes. While it is cost‐effective in dry weather, it can lead to overflows during heavy rain, causing untreated wastewater to discharge into rivers or streets.
Which process uses a membrane to separate impurities from water?
A Coagulation
B Filtration
C Reverse osmosis
D Sedimentation
Reverse osmosis uses a semi‐permeable membrane to remove dissolved salts, minerals, and impurities from water. It is commonly used for desalination and water purification, producing clean water from brackish or seawater.
What is a primary function of a chlorination system in water treatment?
A Add minerals
B Remove bacteria
C Clarify water
D Remove solids
Chlorination is used to disinfect water by killing or neutralizing harmful bacteria, viruses, and pathogens. It is one of the most effective and widely used methods to ensure water safety for consumption.
What does the term “greywater” refer to?
A Water with high salinity
B Water from sinks and showers
C Polluted water
D Water from toilets
Greywater refers to wastewater from non‐toilet sources like sinks, showers, and washing machines. It can be treated and reused for non‐potable purposes such as irrigation or toilet flushing.
What is typically used to remove bacteria from water?
A Aeration
B Sedimentation
C Chlorination
D Filtration
Chlorination is a chemical disinfection process used to remove or inactivate harmful bacteria and microorganisms from water. It is a cost‐effective and widely used method for ensuring safe drinking water.
What is the role of filtration in water treatment?
A Remove large particles
B Remove dissolved salts
C Add chlorine
D Remove dissolved gases
Filtration is a mechanical process that removes large particles, such as dirt, debris, and sediment, from water. It is one of the first steps in water treatment before further disinfection and purification processes.