This set of Waste Water Engineering Multiple Choice Questions & Answers (MCQs) focuses on “Effluent Disposal in Septic Tanks”.
1. Effluent sewer is also called as ______
a) Septic tank drainage
c) Septic tank effluent drainage
d) Effluent drainage
Explanation: Effluent sewer system is also called as Septic Tank Effluent Drainage (STED) or solids-free sewer (SFS) systems. These have septic tanks that collect sewage from residences and businesses.
2. Gravity systems are preferred over pumping systems for the flow of wastewater.
Explanation: Most of the solids are removed by the septic tanks, so the treatment plant can be much smaller than a typical plant. A pumping system can be used to move the wastewater rather than a gravity system as there is a vast reduction in wastewater.
3. What is the function of two tanks provided in septic tank systems?
a) Divide solids and liquid
b) Divide wastewater and water
c) Divide black and grey water
d) Store large amount of effluent
Explanation: Septic systems are commonly used to treat waste water. There might be one tank that combines all black and grey water or two tanks that divide the black and grey water.
4. The longer the water is held in the tank, the better the treatment.
Explanation: Wastewater is treated by bacteria that live in the septic tank. The longer the water is held in the tank, the better the treatment. Crowded households may produce large quantities of grey water from constant use of the washing machine, shower and bath.
5. Large amount of wastewater constantly produced _________ the treatment time of wastewater in a septic tank.
c) Does not alter
Explanation: If a large amount of grey water is constantly produced, it will shorten the treatment time of wastewater in the septic tank. Leaking taps, valves and toilet cisterns also increase the amount of water entering the septic system and can further reduce treatment time.
6. ______ is called effluent.
b) Untreated wastewater
c) Treated wastewater
d) Untreated water
Explanation: Treated wastewater is called ‘effluent’. In some communities, the effluent is piped from each house to a collection point for further treatment and disposal. This is called a Common Effluent Drain system (CED).
7. What is the common effluent pipe from each house to a collection point called?
Explanation: In some communities, the effluent is piped from each house to a collection point for further treatment and disposal. This is called a Common Effluent Drain system (CED). Effluent disposal can also occur at the house site through absorption trenches, which consist of underground trenches that allow the water to soak into the ground.
8. ______ allow the water to soak into the ground.
a) Septic tank
c) Effluent pipe
Explanation: Effluent disposal can also occur at the house site through absorption trenches, which consist of underground trenches that allow the water to soak into the ground.
Sanfoundry Global Education & Learning Series – Waste Water Engineering.
To practice all areas of Waste Water Engineering, here is complete set of 1000+ Multiple Choice Questions and Answers.