Question

A large quantity of urban sewage is drained into the nearby Village River. Which among the given conditions would happen after mixing of sewage into the river?
i. Biochemical oxygen demand (BOD) of receiving water bodies increases.
ii. Dissolved oxygen of the receiving water body decreases.
iii. It will not cause mortality among fishes and other aquatic creatures.
iv. It will lead to the nutrient enrichment of receiving water bodies.
A. i,ii and iv
B. i,ⅱ and iv
C. ii and iii only
D. iii and iv only

Answer 1

Hint: The main components of the urban water cycle consisting of water supply, wastewater disposal, and stormwater drainage. Enhancing and utilizing the natural water cycle is an important step toward more sustainable urban environments. Some measures for Water management and some practice for new developments must be based on social, economic, and environmental sustainability aspects. The main target of conventional urban water management practices is to meet water demand while conveying wastewater and stormwater away from urban settings.

Complete answer:
Urban sewage in huge quantities will for the most component have a form of a massive quantity of organic and inorganic material, which is opposite to popular belief. Due to this, the decomposition of the organic mass will sort of initiate the use of dissolved oxygen and so, the dissolved oxygen of the receiving water body decreases, which directly indicates that sincerely urban sewage in huge quantities will mostly have a reasonably big amount of organic and inorganic material, which essentially is considerable. This can cause an increase within the for all intents and functions of organic oxygen demand (BOD) using the decomposing bacteria in a diffused way. Because the dissolved oxygen decreases, the aquatic animals will suffocate and essentially die hugely. also, the inorganic nutrients, in addition to the decomposed vitamins, will cause lush growth of algae, causing for all intents and functions algal bloom over the floor of the water, with a purpose to virtually, also, decrease the dissolved oxygen by no longer allowing the combination of atmospheric oxygen, which is fairly full-size.

Hence, the correct answer is option B.

Note:
Sewage is characterized by volume or rate of flow, very physical condition, kind of chemical and fairly toxic constituents, and its bacteriologic status. Sewage usually actually travels from a building’s plumbing either into a sewer, which will carry it elsewhere or into an onsite sewage facility, which essentially shows that sewage is a type of wastewater that essentially is produced by a community of people, which is quite significant.