Texas Wastewater B exam questions with correct
answers
Course
WASTEWATER
Question 1
What is the primary purpose of a wastewater treatment plant? A) To produce drinking water
B) To remove pollutants from wastewater
C) To increase the temperature of wastewater
D) To provide irrigation for agricultural land
Answer: B) To remove pollutants from wastewater
Rationale: The main function of a wastewater treatment plant is to treat and remove
contaminants from wastewater before it is released into the environment or returned to water
bodies.
Question 2
What is the typical range of biochemical oxygen demand (BOD) for domestic wastewater?
A) 5-20 mg/L
B) 20-300 mg/L
C) 300-600 mg/L
D) 600-1000 mg/L
Answer: B) 20-300 mg/L
Rationale: Domestic wastewater typically has a BOD range of 20 to 300 mg/L, indicating
the amount of oxygen required to biologically degrade organic matter in the water.
Question 3
Which of the following processes is primarily used for the biological treatment of
wastewater? A) Filtration
B) Activated sludge process
C) Sedimentation
D) Disinfection
Answer: B) Activated sludge process
Rationale: The activated sludge process is a common biological treatment method where
microorganisms digest organic pollutants in wastewater, effectively reducing BOD levels.
Question 4
,What is the primary function of a clarifier in a wastewater treatment plant? A) To aerate the
wastewater
B) To filter out solid particles
C) To separate sludge from treated water
D) To disinfect the effluent
Answer: C) To separate sludge from treated water
Rationale: Clarifiers allow for the settling of suspended solids, separating sludge from the
treated water, which is essential for proper wastewater treatment.
Question 5
Which chemical is commonly used for disinfection in wastewater treatment? A) Ammonia
B) Chlorine
C) Sulfuric acid
D) Sodium bicarbonate
Answer: B) Chlorine
Rationale: Chlorine is widely used for disinfection in wastewater treatment processes to kill
pathogens and ensure that the effluent is safe for discharge or reuse.
Question 6
What is the significance of total suspended solids (TSS) in wastewater treatment? A) It
indicates the level of nutrient content
B) It measures the amount of dissolved oxygen
C) It helps determine the effectiveness of filtration processes
D) It quantifies the total number of bacteria present
Answer: C) It helps determine the effectiveness of filtration processes
Rationale: Total suspended solids (TSS) represent solid particles in the water that can
interfere with treatment processes and affect effluent quality; monitoring TSS helps assess the
effectiveness of the treatment.
Question 7
What does the term "influent" refer to in wastewater treatment? A) The treated water that is
discharged
B) The wastewater entering the treatment plant
C) The sludge removed from the treatment process
D) The chemical additives used for treatment
,Answer: B) The wastewater entering the treatment plant
Rationale: "Influent" refers to the flow of wastewater that enters a treatment plant for
processing before being treated and discharged.
Question 8
What is the purpose of secondary treatment in wastewater treatment? A) To remove
pathogens
B) To reduce BOD and TSS
C) To remove nutrients
D) To enhance sludge settling
Answer: B) To reduce BOD and TSS
Rationale: Secondary treatment aims to further reduce BOD and total suspended solids
(TSS) from the wastewater after primary treatment, primarily through biological processes.
Question 9
Which of the following is a common method for sludge disposal? A) Landfilling
B) Direct discharge to water bodies
C) Incineration
D) Both A and C
Answer: D) Both A and C
Rationale: Common methods for sludge disposal include landfilling and incineration, where
the sludge is either buried or burned to minimize its volume and potential environmental
impact.
Question 10
What is the primary function of a screen in a wastewater treatment system? A) To aerate the
influent
B) To remove large solids from the wastewater
C) To provide chemical treatment
D) To facilitate microbial activity
Answer: B) To remove large solids from the wastewater
Rationale: Screens are used to remove large debris and solids from the influent, preventing
damage to equipment and ensuring smoother operation in the treatment process.
Question 11
, What is the main objective of pretreatment in wastewater management? A) To treat
wastewater for direct discharge
B) To remove specific contaminants before wastewater enters the treatment facility
C) To disinfect treated effluent
D) To reduce the volume of sludge generated
Answer: B) To remove specific contaminants before wastewater enters the treatment facility
Rationale: Pretreatment aims to eliminate harmful substances that could disrupt the
treatment process, ensuring that the wastewater is suitable for further treatment.
Question 12
What is the typical pH range for treated wastewater to meet discharge standards? A) 4.0-5.0
B) 6.0-9.0
C) 7.5-8.5
D) 9.0-10.0
Answer: B) 6.0-9.0
Rationale: Treated wastewater typically must have a pH in the range of 6.0 to 9.0 to comply
with environmental regulations for discharge.
Question 13
What is the purpose of adding coagulants during wastewater treatment? A) To enhance
biological activity
B) To aid in the removal of suspended solids
C) To increase dissolved oxygen levels
D) To neutralize acids in the water
Answer: B) To aid in the removal of suspended solids
Rationale: Coagulants help aggregate small particles into larger flocs, making it easier to
remove suspended solids during the treatment process.
Question 14
In a wastewater treatment plant, what does the term "effluent" refer to? A) Raw wastewater
B) The sludge removed from the treatment process
C) Treated water that is discharged from the plant
D) The chemicals used for disinfection
Answer: C) Treated water that is discharged from the plant
Rationale: "Effluent" is the term used to describe the treated wastewater that is released from
the treatment facility into the environment.
answers
Course
WASTEWATER
Question 1
What is the primary purpose of a wastewater treatment plant? A) To produce drinking water
B) To remove pollutants from wastewater
C) To increase the temperature of wastewater
D) To provide irrigation for agricultural land
Answer: B) To remove pollutants from wastewater
Rationale: The main function of a wastewater treatment plant is to treat and remove
contaminants from wastewater before it is released into the environment or returned to water
bodies.
Question 2
What is the typical range of biochemical oxygen demand (BOD) for domestic wastewater?
A) 5-20 mg/L
B) 20-300 mg/L
C) 300-600 mg/L
D) 600-1000 mg/L
Answer: B) 20-300 mg/L
Rationale: Domestic wastewater typically has a BOD range of 20 to 300 mg/L, indicating
the amount of oxygen required to biologically degrade organic matter in the water.
Question 3
Which of the following processes is primarily used for the biological treatment of
wastewater? A) Filtration
B) Activated sludge process
C) Sedimentation
D) Disinfection
Answer: B) Activated sludge process
Rationale: The activated sludge process is a common biological treatment method where
microorganisms digest organic pollutants in wastewater, effectively reducing BOD levels.
Question 4
,What is the primary function of a clarifier in a wastewater treatment plant? A) To aerate the
wastewater
B) To filter out solid particles
C) To separate sludge from treated water
D) To disinfect the effluent
Answer: C) To separate sludge from treated water
Rationale: Clarifiers allow for the settling of suspended solids, separating sludge from the
treated water, which is essential for proper wastewater treatment.
Question 5
Which chemical is commonly used for disinfection in wastewater treatment? A) Ammonia
B) Chlorine
C) Sulfuric acid
D) Sodium bicarbonate
Answer: B) Chlorine
Rationale: Chlorine is widely used for disinfection in wastewater treatment processes to kill
pathogens and ensure that the effluent is safe for discharge or reuse.
Question 6
What is the significance of total suspended solids (TSS) in wastewater treatment? A) It
indicates the level of nutrient content
B) It measures the amount of dissolved oxygen
C) It helps determine the effectiveness of filtration processes
D) It quantifies the total number of bacteria present
Answer: C) It helps determine the effectiveness of filtration processes
Rationale: Total suspended solids (TSS) represent solid particles in the water that can
interfere with treatment processes and affect effluent quality; monitoring TSS helps assess the
effectiveness of the treatment.
Question 7
What does the term "influent" refer to in wastewater treatment? A) The treated water that is
discharged
B) The wastewater entering the treatment plant
C) The sludge removed from the treatment process
D) The chemical additives used for treatment
,Answer: B) The wastewater entering the treatment plant
Rationale: "Influent" refers to the flow of wastewater that enters a treatment plant for
processing before being treated and discharged.
Question 8
What is the purpose of secondary treatment in wastewater treatment? A) To remove
pathogens
B) To reduce BOD and TSS
C) To remove nutrients
D) To enhance sludge settling
Answer: B) To reduce BOD and TSS
Rationale: Secondary treatment aims to further reduce BOD and total suspended solids
(TSS) from the wastewater after primary treatment, primarily through biological processes.
Question 9
Which of the following is a common method for sludge disposal? A) Landfilling
B) Direct discharge to water bodies
C) Incineration
D) Both A and C
Answer: D) Both A and C
Rationale: Common methods for sludge disposal include landfilling and incineration, where
the sludge is either buried or burned to minimize its volume and potential environmental
impact.
Question 10
What is the primary function of a screen in a wastewater treatment system? A) To aerate the
influent
B) To remove large solids from the wastewater
C) To provide chemical treatment
D) To facilitate microbial activity
Answer: B) To remove large solids from the wastewater
Rationale: Screens are used to remove large debris and solids from the influent, preventing
damage to equipment and ensuring smoother operation in the treatment process.
Question 11
, What is the main objective of pretreatment in wastewater management? A) To treat
wastewater for direct discharge
B) To remove specific contaminants before wastewater enters the treatment facility
C) To disinfect treated effluent
D) To reduce the volume of sludge generated
Answer: B) To remove specific contaminants before wastewater enters the treatment facility
Rationale: Pretreatment aims to eliminate harmful substances that could disrupt the
treatment process, ensuring that the wastewater is suitable for further treatment.
Question 12
What is the typical pH range for treated wastewater to meet discharge standards? A) 4.0-5.0
B) 6.0-9.0
C) 7.5-8.5
D) 9.0-10.0
Answer: B) 6.0-9.0
Rationale: Treated wastewater typically must have a pH in the range of 6.0 to 9.0 to comply
with environmental regulations for discharge.
Question 13
What is the purpose of adding coagulants during wastewater treatment? A) To enhance
biological activity
B) To aid in the removal of suspended solids
C) To increase dissolved oxygen levels
D) To neutralize acids in the water
Answer: B) To aid in the removal of suspended solids
Rationale: Coagulants help aggregate small particles into larger flocs, making it easier to
remove suspended solids during the treatment process.
Question 14
In a wastewater treatment plant, what does the term "effluent" refer to? A) Raw wastewater
B) The sludge removed from the treatment process
C) Treated water that is discharged from the plant
D) The chemicals used for disinfection
Answer: C) Treated water that is discharged from the plant
Rationale: "Effluent" is the term used to describe the treated wastewater that is released from
the treatment facility into the environment.
