AP Environmental Science Practice Quiz: Sewage Treatment
Written by AP Content Team, Verified for 2026 AP Exams, Last updated: May 2026
Test your understanding with short quizzes. This quiz has 11 questions to check your progress.
Question 1 of 11
All Questions (11)
A) A biological process using bacteria
B) The physical removal of large objects
C) Disinfection with chlorine or UV light
D) The use of chemical processes to remove pollutants
Correct Answer: B
The text states that 'Primary treatment of sewage is the physical removal of large objects, followed by the settling of solid waste in the bottom of a tank.' This is the first described stage.
A) To help large objects float to the surface for removal
B) To mix in chemical disinfectants like chlorine
C) To increase the rate at which bacteria break down organic matter
D) To physically filter out any remaining solid waste
Correct Answer: C
The content specifies that during secondary treatment, 'The tank is aerated to increase the rate of breakdown' by bacteria.
A) Primary treatment
B) Secondary treatment
C) Disinfection
D) Tertiary treatment
Correct Answer: B
The text explicitly defines secondary treatment as 'a biological process in which bacteria break down organic matter.'
A) A second round of primary treatment
B) Enhanced aeration
C) Tertiary treatment
D) Pre-discharge disinfection
Correct Answer: C
Tertiary treatment is defined as 'the use of ecological or chemical processes to remove any pollutants left in the water after primary and secondary treatment.'
A) Aeration
B) Settling
C) Bacterial decomposition
D) UV light
Correct Answer: D
The text states that prior to discharge, water is exposed to disinfectants, giving 'chlorine, ozone, or UV light' as examples.
A) Primary treatment
B) Secondary treatment
C) Tertiary treatment
D) Disinfection
Correct Answer: B
Secondary treatment is the biological process that relies on 'bacteria [to] break down organic matter.' A failure in the bacterial culture would cripple this specific stage.
A) Primary treatment
B) Secondary treatment
C) Tertiary treatment
D) Disinfection
Correct Answer: A
The description of primary treatment includes 'the settling of solid waste in the bottom of a tank.'
A) Disinfection -> Secondary Treatment -> Primary Treatment
B) Primary Treatment -> Tertiary Treatment -> Secondary Treatment
C) Secondary Treatment -> Disinfection -> Tertiary Treatment
D) Primary Treatment -> Secondary Treatment -> Disinfection
Correct Answer: D
Based on the text, the logical flow is physical removal (Primary), followed by biological breakdown (Secondary), and finally killing bacteria (Disinfection) prior to discharge. Tertiary treatment is an additional step after secondary if needed.
A) Large physical objects and solid waste
B) Ozone and UV light
C) Carbon dioxide and inorganic sludge
D) Clean water and chlorine
Correct Answer: C
The text states that in secondary treatment, 'bacteria break down organic matter into carbon dioxide and inorganic sludge.'
A) To remove leftover chemical pollutants like nitrates
B) To kill bacteria
C) To break down organic matter
D) To remove large physical objects
Correct Answer: B
The text distinguishes the final step by stating, 'the treated water is exposed to one or more disinfectants... to kill bacteria.' This is different from tertiary treatment, which removes pollutants.
A) Physical and settling processes
B) Biological and aeration processes
C) Disinfection and sterilization processes
D) Ecological or chemical processes
Correct Answer: D
The content defines tertiary treatment as 'the use of ecological or chemical processes to remove any pollutants left in the water after primary and secondary treatment,' distinguishing it from the physical nature of primary and biological nature of secondary treatment.