Hotel Service Unit 10 Q10 Quiz

Hotel Service Unit 10 Sewage Q10

1 / 10

What happens in the primary treatment stage of an aerobic sewage treatment plant?

C) Chemical disinfectants are added

B) Large solids and debris are separated from the liquid sewage through mechanical screening or sedimentation

D) The sewage is heated to kill bacteria

A) Oxygen is bubbled through the sewage

2 / 10

Why are aerobic bacteria critical to the operation of an aerobic sewage treatment plant?

A) They increase the temperature of the sewage

D) They reduce the acidity of the sewage

B) They break down organic waste efficiently in the presence of oxygen, converting it into harmless byproducts like water and carbon dioxide

C) They produce methane for energy generation

3 / 10

What occurs during the secondary treatment stage in an aerobic sewage treatment plant?

D) Heavy metals are removed

B) Aerobic bacteria break down dissolved organic matter using oxygen provided during aeration

A) Further mechanical separation of solids

C) The sewage is chlorinated

4 / 10

What is the purpose of the aeration stage in an aerobic sewage treatment plant?

B) To provide oxygen to aerobic bacteria, allowing them to break down organic matter in the sewage

A) To mix the sewage and water

D) To sterilize the sewage using heat

C) To evaporate the water content in the sewage

5 / 10

How do aerobic bacteria contribute to the operation of an aerobic sewage treatment plant?

A) They use oxygen to break down organic matter in sewage, converting it into simpler substances such as water and carbon dioxide

C) They chemically neutralize sewage without oxygen

D) They increase the temperature of the sewage, evaporating the waste

B) They thrive in the absence of oxygen and produce methane and hydrogen sulfide

6 / 10

What happens to the sludge that is separated during the settling stage?

D) It is used to generate heat for the plant

C) It is mixed back into the treated sewage

A) It is discharged directly into the sea

B) It is further treated or disposed of in accordance with environmental regulations

7 / 10

How is a continuous oxygen supply ensured in an aerobic sewage treatment plant?

C) By reducing the flow of sewage into the plant

D) By adding chemicals to the sewage

A) By heating the sewage

B) By using aeration systems, such as air diffusers or mechanical aerators, to continuously bubble air through the effluent

8 / 10

What is the purpose of the settling or clarification stage in an aerobic sewage treatment plant?

C) To increase the pH of the sewage

B) To reintroduce oxygen into the sewage

A) To separate solids from the liquid by allowing them to settle at the bottom

D) To heat the sewage for faster breakdown

9 / 10

What is the purpose of the tertiary treatment stage in an aerobic sewage treatment plant?

B) To remove large solids from the sewage

D) To add more waste to the system

C) To reduce the temperature of the sewage

A) To further purify the treated sewage through filtration, disinfection, or other processes to make it safe for discharge

10 / 10

How is treated sewage disinfected before discharge in an aerobic sewage treatment plant?

B) By adding disinfectants such as chlorine or using ultraviolet (UV) light to kill remaining pathogens

D) By mixing with seawater

C) By adding oxygen

A) By heating the sewage to high temperatures

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