CBSE Class 7 Science Wastewater Story Worksheet with Solution by Expert Science Mam. Students of 7th Grade can solve this worksheet for extra preparation before exam. Private Teacher or Guardians of the Students can copy all the questions of this chapter and will match after solve their students.
Wastewater Story Class 7 Worksheet
The following questions are important for your exams for 1 mark 2 mark or 5 marks. First solve the questions on your own and then saw the solution for understanding it better.
Practice worksheet for class 7
Section A
Q.1) What do you mean by waste water?
→ The dirty water that goes down the drains from sinks, showers, toilets and laundries is called as wastewater.
Q.2) What is sewage treatment?
→ Cleaning of water is a process of removing pollutants before it enters a water body or is reuse. This process of wastewater treatment is commonly known as a sewage treatment.
Q.3) What do you mean by sewage?
→ Sewage is wastewater released by homes, industries, hospitals , officers and other users. It also includes run water that run down the straight during a heavy rain the water that washers of roads and rooftops carries harmful substances with it sewage is a liquid waste.
Q.4) Which kind of organic impurities and inorganic impurities found in sewage water?
→
1.) Organic impurities such as human faeces, animal waste, oil , urea , pesticides herbicides, fruits and vegetable waste.
2.) Inorganic imperative like nitrates phosphate and metals.
Q.5) What is sewers and sewerage ?
→ The network of big and small pipes which carrying clean water and Waste water called as sewers and it forms the sewerage.
Q.6) Which kind of tree absorb the wastewater ?
→The eucalyptus tree absorbs the surplus water rapidly and released pure water vapor into the atmosphere.
Q.7) What are the vermin processing toilets?
→ Design of toilets in which human excreta is a treated by earthworm has been tested in India. The operation of the toilet is very simple and hygienic. it is found that low water use toilet for safe processing of human waste. The human excreta is completely converted to vermin cakes which is much needed resource for fun.
Q.8) How the sludge can be treated?
→ Solids like feces settle at the bottom and this solid material called as sludge. Sledge is removed using a skimmer and then it is transported into a tank and later it is decomposed by anaerobic bacteria to produce biogas.
Q.9) How untreated human feces are harmful?
→ Untreated human feces are harmful because it consists of various microorganisms and pollutants that will contaminate and destroy the structure of soil and water resources. When people drink or use the water from this kind of resources, they get infected by the diseases like typhoid , dysentery and cholera etc.
Q.10) What is wastewater management?
→ Wastewater management is a process used to remove contaminants and harmful microorganisms from the water to make it reusable.
1.) Waste water collection.
2.) Screening
3.) Primary treatment
4.) Secondary treatment.
5.) Final treatment of water.
Q.11) Define the process of screening?
→Screening is one of the stages in the process of treatment of water. In this process the larger objects are removed from wastewater and then moved into the grit and sand removal tank.
Q.12) What we can do for the better sewage system in household work?
→
1.) Do not throw cooking oils and fats in the drain as it blocks the pipes.
2.) Reuse the tea leaves and remaining food for the process of composting.
3.) Do not throw used sanitary pads and soft toys in the drains.
Q.13) What is vermin processing?
→ Verme refers to a small worm such as earthworms. Verme processing toilets are those toilets in which humans’ excreta is treated by earthworms.
Q.14) Explain the primary treatment of wastewater treatment?
→The primary treatment :-
1.) The waste water is taken for a primary treatment after the process of screening where all the organic Waste like animal waste, human fecesetc. is removed.
2.) It is done by collecting the waste water into bigger tanks for the solid matter to settle at the surface of the tank.
Q.15) Explain the secondary treatment of the Waste water management?
→
1.) After the primary treatment the water through a tank called aeration lane where the air is tapped into the water to increase the growth of aerobic bacteria.
2.) Bacteria breakdown the particles of sludge that escaped after primary treatment.
Q.16) Explain the final treatment of wastewater management?
→
1.) After the secondary treatment the activated sledge is passed through a bed of sand drying machine where the sludge is dried up and water is filtered out.
2.) The west water is directed to flow over a wall where it gets filtered through a sand bed to eliminate the impurities if found.
3.) Then water is filtered and allowed to pass into a river.
4.) After the water is totally filtered and can be used for household duties.