This set of Waste Water Engineering Multiple Choice Questions & Answers (MCQs) focuses on “Sewer Sections”.
Explanation: It becomes uneconomical to lay separate systems for both sanitary sewage and storm water. Hence a combined system is used in countries like India which is a developing country and also because the rainfall is moderate.
2. Partial sewers carry a part of storm water to sanitary sewers.
Explanation: In partial sewer systems a part of storm water during rain is allowed to enter sanitary sewer while the remaining storm water is carried through open drains to the point of disposal.
3. Two sets of sewers are laid in _________ system.
d) Partially combined
Explanation: In separate systems, two sets of sewers are laid. The sanitary sewage is carried through sanitary sewers while the storm sewage is carried through storm sewers. The sewage is carried to the treatment plant and storm water is disposed of to the river.
4. Which of the following is an advantage of separate sewers?
a) Rivers are polluted
b) Size of the sewers are small
c) It proves economical
d) Nuisance potential is reduced
Explanation: In separate sewer systems, as two sets of sewers are used, the quantity of wastewater flow will also be less in sewers. Hence the size of the sewers will be small. As two sewers are used, it doesn’t prove to be economical.
Explanation: In separate systems, two sets of sewers are used to carry sanitary sewage and storm/ surface water separately. In the combined system, a single sewer with a larger size is used to carry both sanitary sewage and surface water together.
6. If sizes of the sewers are __________ choking problems are less.
Explanation: Combined sewer systems consist of only one sewer to carry out both storm water and sanitary sewage. Hence the size of the sewers should be large. Large sewers are easy to clean and avoid choking problems.
7. Which of the following is a disadvantage with respect to the size of the sewers?
b) Choking problems
c) Handling and transportation
Explanation: As the combined systems consist of a single large sewer to carry both sanitary sewage and storm water, it is easy to clean and choking problems are avoided. As the size of the sewers is large, it becomes difficult to handle and transport the sewer pipes.
8. In which kind of cities are combined systems used?
a) Less population
b) High population
c) High residences
d) High storm
Explanation: If a city has less population, it consists of less residences and industries based on the city needs. Hence the quantity of sanitary sewage produced will also be less. It becomes uneconomical to lay separate sewers for both storm water and sanitary sewage. Hence combined systems are preferred.
Explanation: In dry weather flow the storm water is less or absent. During wet weather flow, the quantity of storm water increases. As in partial systems, a part of storm water is direct to sanitary sewers, the storm water puts a load on treatment plants by increasing the quantity of water to be treated.
10. The treatment is costly in which of the following systems?
Explanation: Combined systems consist of both storm water and sanitary sewage. Hence it becomes costly for as the treatment for both are done. In separate systems, the required amount of treatment is done for storm water and sanitary sewage separately.
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.