Hotel Service Unit 10 Q11 Quiz

Correct Answer:
B) By testing the sewage to ensure it meets regulatory standards for cleanliness and safety, including proper disinfection and sludge management

Explanation:
Before discharge, treated sewage is tested to ensure it complies with environmental regulations. This involves checking for proper disinfection, low levels of harmful substances, and safe management of sludge to protect the environment.

Correct Answer:
A) Large solids are mechanically separated from the liquid sewage through screening and sedimentation

Explanation:
In the primary treatment stage, large solids and debris are removed from the sewage through screening and sedimentation. This reduces the load on the biological processes that follow and helps ensure smooth operation of the plant.

Correct Answer:
B) They break down organic waste in the presence of oxygen, converting it into water and carbon dioxide

Explanation:
Aerobic bacteria are critical to the sewage treatment process as they metabolize organic waste in the presence of oxygen. This biological breakdown converts harmful waste into non-toxic substances such as water and carbon dioxide, making the sewage safe for discharge.

Correct Answer:
B) Aerobic bacteria further break down dissolved and suspended organic matter using oxygen

Explanation:
In the secondary treatment stage, aerobic bacteria continue to break down the dissolved and suspended organic matter with the help of oxygen provided during aeration. This stage reduces the biological load of the sewage.

Correct Answer:
B) By continuously bubbling air through the effluent using aeration devices

Explanation:
Aeration devices continuously bubble air through the effluent, supplying the oxygen required by aerobic bacteria to break down organic waste efficiently. This process ensures the biological treatment system operates effectively.

Correct Answer:
B) To kill remaining bacteria or pathogens in the treated sewage, ensuring it meets environmental safety standards

Explanation:
Disinfection, often done using chlorine or UV light, is the final step in the treatment process to eliminate any remaining bacteria or pathogens. This ensures that the treated sewage is safe for discharge into the environment.

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

Explanation:
The aeration stage supplies oxygen to the aerobic bacteria that break down organic matter in the sewage. By bubbling air through the effluent, aerobic bacteria can metabolize waste and convert it into harmless byproducts.

Correct Answer:
B) To further purify the sewage through filtration or disinfection, ensuring it is safe for discharge

Explanation:
In the tertiary treatment stage, the treated sewage undergoes further purification through filtration or disinfection processes (e.g., chlorination or UV treatment) to ensure that it meets environmental standards for safe discharge.

Correct Answer:
B) It is further treated and disposed of according to environmental regulations

Explanation:
The sludge collected during the settling stage often contains concentrated waste and must be treated or disposed of according to environmental guidelines. This ensures that the sludge does not cause pollution or harm the ecosystem.

Correct Answer:
B) To allow the treated sewage to settle so that solids (sludge) can separate from the liquid

Explanation:
During the settling stage, the sewage is allowed to rest, enabling solids (sludge) to sink to the bottom while the treated liquid effluent rises to the top. This stage separates the remaining solid matter from the treated liquid.