9394949438

[LATEST]$type=sticky$show=home$rm=0$va=0$count=4$va=0

 


NCERT Solutions for Class 7 Science Chapter 18 Wastewater Story

NCERT solutions for class 7 science chapter 18 wastewater story exercise:

  1. Fill in the blanks:
    (a) Cleaning of water is a process of removing ____________.
    (b) Wastewater released by houses is called ____________.
    (c) Dried ____________ is used as manure.
    (d) Drains get blocked by ____________ and ____________.

Answer:

(a) Cleaning of water is a process of removing contaminants .
(b) Wastewater released by houses is called sewage .
(c) Dried cow dung is used as manure.
(d) Drains get blocked by plastic and fats .

. What is sewage? Explain why it is harmful to discharge untreated sewage into rivers or seas.

Answer:

Sewage is wastewater coming out of households, public places, farms and industry. It also includes rainwater which has flown into the sewers.

Untreated sewage contains harmful chemicals which if released directly into the rivers or seas would pollute them harming the ecosystem of the water bodies and making the water unfit for drinking or further use.

. Why should oils and fats be not released in the drain? Explain.

Answer:

Oils and fats are insoluble in water. When released in the drain, it causes hardening and blocking of the sewage pipes. In an open drain, the fats block the soil pores which is required for filtering water. That is why oil and fats should not be released in the drain.

. Describe the steps involved in getting clarified water from wastewater.

Answer:

The treatment of wastewater includes the following steps:

(i) First, the physical waste like plastic, rags, pebbles, wood etc is removed by passing the water through a bar screen.

(ii) Then water is sent into sand removal tank for removing sand, pebbles, grit etc. through the process of sedimentation.

(iii) Then the rest of the solid waste is allowed to settle at the bottom of a large settling tank. This waste deposited at the bottom is called sludge and is removed through a scraper.

(iv) The harmful microorganisms in this water are killed through chlorination or UV rays.

(v) Through aerator, air is pumped into this water so that aerobic bacteria can grow and decompose any remaining organic wastes.

(vi) This treated water is then released into the water bodies.

. What is sludge? Explain how it is treated.

Answer:

Sludge is the solid waste which has settled at the bottom of settling tanks during the process of wastewater treatment.

It is treated by decomposition by anaerobic bacteria. This activated sludge further can be used as manure.

. Untreated human excreta is a health hazard. Explain.

Answer:

Untreated human excreta contains many harmful organisms which can cause lots of health-related problems. Untreated human excreta pollutes air, water and soil. Epidemics like cholera, meningitis etc. can be spread by untreated human excreta.

. Name two chemicals used to disinfect water.

Answer:

Two chemicals used to disinfect water are Chlorine and Ozone.

  1. Explain the function of bar screens in a wastewater treatment plant.

Answer:

Bar screens filter most of the large-sized solid waste like plastic, cans, wood etc from wastewater.

  1. Explain the relationship between sanitation and disease.

Answer:

Sanitation refers to the availability of clean drinking water and proper treatment of human waste and sewage.

Without proper sanitation various diseases like cholera, typhoid, diarrhoea, etc. would spread and proper sanitation ensures that these diseases do not spread.

10 . Outline your role as an active citizen in relation to sanitation.

Answer:

As an active citizen, we should ensure that proper sanitation facilities are available in our home and workplaces, should make people aware about the necessity of sanitation and should not throw garbage in the open as it will block the drains and restrict the flow of the sewage.

  1. Here is a crossword puzzle: Good luck!

Across
. Liquid waste products
. Solid waste extracted in sewage treatment
. A word related to hygiene
. The waste matter discharged from the human body
Down
. Used water
. A pipe carrying sewage
. Micro-organisms which causes cholera
. A chemical to disinfect water

Answer:

Across
. SEWAGE
. SLUDGE
. SANITATION
. EXCRETA
Down
. WASTEWATER
. SEWER
. BACTERIA
. OZONE

  1. Study the following statements about ozone:

(a) It is essential for breathing of living organisms.
(b) It is used to disinfect water.
(c) It absorbs ultraviolet rays.
(d) Its proportion in air is about 3%.

Which of these statements are correct?
(i) (a), (b) and (c)
(ii) (b) and (c)
(iii) (a) and (d)
(iv) All four

Answer:

(ii) (b) and (c) are correct.

Responsive Table
Chapter No. Chapter Name
Chapter 1 NCERT solutions for class 7 science chapter 1 Nutrition in Plants
Chapter 2 NCERT Solutions for class 7 science chapter 2 Nutrition in Animals
Chapter 3 NCERT solutions for class 7 science chapter 3 Fibre to Fabric
Chapter 4 NCERT solutions for class 7 chapter 4 science Heat
Chapter 5 NCERT solutions for class 7 science chapter 5 Acids Bases and Salts
Chapter 6 NCERT solutions for class 7 science chapter 6 Physical and Chemical Changes
Chapter 7 NCERT solutions for class 7 science chapter 7 Weather Climate and Adaptations of Animals to Climate
Chapter 8 NCERT solutions for class 7 science chapter 8 Winds, storms and cyclones
Chapter 9 NCERT solutions for class 7 science chapter 9 Soil
Chapter 10 NCERT solutions for class 7 chapter 10 Respiration in Organisms
Chapter 11 NCERT solutions for class 7 science chapter 11 Transportation in Animals and Plants
Chapter 12 NCERT solutions for class 7 science chapter 12 Reproduction in Plants
Chapter 13 NCERT solutions for class 7 science chapter 13 Motion and Time
Chapter 14 NCERT solutions for class 7 science chapter 14 Electric Current and its Effects
Chapter 15 NCERT Solutions for class 7 science chapter 15 science Light
Chapter 16 NCERT solutions for class 7 science chapter 16 Water A Precious Resource-
Chapter 17 NCERT solutions for class 7 science chapter 17 Forests Our lifeline
Chapter 18 NCERT solutions for class 7 science chapter 18 Wastewater Story

Study Resources Quick Links

Want to know more

Please fill in the details below:

INNER POST ADS

Latest IITJEE Articles$type=three$c=3$author=hide$comment=hide$rm=hide$date=hide$snippet=hide

Latest NEET Articles$type=three$c=3$author=hide$comment=hide$rm=hide$date=hide$snippet=hide

Name

Admissions,1,Alternating Current,60,AP EAMCET 2020,1,Basic Maths,2,BCECE 2020,1,best books for iit jee,2,best coaching institute for iit,1,best coaching institute for iit jee preparation,1,best iit jee coaching delhi,1,best iit jee coaching in delhi,2,best study material for iit jee,4,BITSAT Registration 2020,1,Blog,62,books for jee preparation,1,books recommended by iit toppers,3,Capacitance,3,CBSE,1,CBSE accounts exam,1,CBSE boards,1,CBSE NEET,9,cbse neet 2019,3,CBSE NEET 2020,1,cbse neet nic,1,Centre of Mass,2,Chemistry,58,Class 12 Physics,15,coaching for jee advanced,1,coaching institute for iit jee,2,Collision,2,COMEDK UGET 2020 Application Form,1,COMEDK UGET 2020 Exam Form,1,COMEDK UGET news,1,CUCET 2020,2,Current Electricity,4,CVR college,1,Digestion and Absorption Notes PDF,1,Electromagnetic Induction,3,Electronics,1,Electrostatics,3,Energy,1,Engineering & Medical,1,Fluid Mechanics,4,Gravitation,2,GUJCET 2020 Application Form,1,Heat,4,iit admission,1,iit advanced,1,iit coaching centre,3,iit coaching centre in delhi,2,iit coaching classes,2,iit coaching in delhi,1,iit coaching institute in delhi,1,iit entrance exam,1,iit entrance exam syllabus,2,iit exam pattern,2,iit jee,5,iit jee 2019,3,iit jee advanced,2,iit jee books,3,iit jee coaching,2,iit jee exam,3,iit jee exam 2019,1,iit jee exam pattern,3,iit jee institute,1,iit jee main 2019,2,iit jee mains,3,iit jee mains syllabus,2,iit jee material,1,iit jee online test,3,iit jee practice test,3,iit jee preparation,6,iit jee preparation in delhi,2,iit jee preparation time,1,iit jee preparation tips by toppers,2,iit jee question paper,1,iit jee study material,3,iit jee study materials,2,iit jee syllabus,2,iit jee syllabus 2019,2,iit jee test,3,iit preparation,2,iit preparation books,5,iit preparation time table,2,iit preparation tips,2,iit syllabus,2,iit test series,3,IITJEE,100,Important Biology Notes for NEET Preparation,1,IPU CET,1,JEE Advanced,83,jee advanced exam,2,jee advanced exam pattern,1,jee advanced paper,1,JEE Books,1,JEE Coaching Delhi,3,jee exam,3,jee exam 2019,6,JEE Exam Pattern,2,jee exam pattern 2019,1,jee exam preparation,1,JEE Main,85,jee main 2019,4,JEE Main 2020,1,JEE Main 2020 Application Form,2,JEE Main 2020 news,2,JEE Main 2020 Official Answer Key,1,JEE Main 2020 Registration,1,JEE Main 2020 Score,1,JEE Main application form,1,jee main coaching,1,JEE Main eligibility criteria,3,jee main exam,1,jee main exam 2019,3,jee main online question paper,1,jee main online test,3,JEE Main Paper-2 Result,1,jee main registration,2,jee main syllabus,2,JEE mains 2020,1,jee mains question bank,1,jee mains test papers,3,JEE Mock Test,2,jee notes,1,jee past papers,1,JEE Preparation,2,jee preparation in delhi,1,jee preparation material,4,JEE Study Material,1,jee syllabus,6,JEE Syllabus Chemistry,1,JEE Syllabus Maths,1,JEE Syllabus Physics,1,jee test series,3,KCET - 2020,1,Kinematics,1,Latest article,5,Latest Articles,61,Latest News,34,latest news about neet exam,1,Laws of Motion,2,Magnetic Effect of Current,3,Magnetism,3,MHT CET 2020,2,MHT CET 2020 exam schedule,1,Modern Physics,1,NCERT Solutions,15,neet,3,neet 2019,1,neet 2019 eligibility criteria,1,neet 2019 exam date,2,neet 2019 test series,2,NEET 2020,2,NEET 2020 Application Form,1,NEET 2020 Eligibility Criteria,1,NEET 2020 Registration,1,neet application form,1,neet application form 2019 last date,1,Neet Biology Syllabus,1,Neet Books,3,neet eligibility criteria,3,neet exam 2019,7,neet exam application,1,neet exam date,1,neet exam details,1,neet exam pattern,6,neet exam pattern 2019,2,neet examination,1,neet mock test 2019,1,Neet Notes,3,Neet Online Application Form,3,neet online test,2,neet past papers,1,neet physics syllabus,1,neet practice test,2,NEET preparation books,1,neet qualification marks,1,NEET question paper 2019,1,neet question papers,1,neet registration,1,Neet Study Material,3,neet syllabus,6,neet syllabus 2019,5,NEET Syllabus 2020,1,neet syllabus chemistry,1,neet syllabus for biology,1,neet syllabus for physics,1,neet test series,1,neet ug 2019,2,news,5,online study material for iit jee,1,Optical Instruments,1,Physics,110,physics books for iit jee,1,Power,1,Practical Physics,1,Quiz,5,Ray Optics,1,Rotational Motion,3,SHM,3,Simple Harmonic Motion,3,study materials for iit jee,1,Study Notes,110,study notes for iit jee,1,Thermodynamics,4,TS EAMCET Notification,2,Units and Dimensions,1,UPSEE 2020,1,UPSEE 2020 Application Form,2,UPSEE EXAM,1,Vectors,2,VITEE Application form,1,Wave Motion,3,Wave Optics,1,WBJEE 2020 Admit Card,1,WBJEE 2020 Answer Key,1,Work,1,
ltr
static_page
BEST NEET COACHING CENTER | BEST IIT JEE COACHING INSTITUTE | BEST NEET & IIT JEE COACHING: NCERT Solutions for Class 7 Science Chapter 18 Waste water Story
NCERT Solutions for Class 7 Science Chapter 18 Waste water Story
The CBSE NCERT Solutions for Class 7 Science Chapter 18 Waste water Story are very useful for students to prepare for final exams. Click to download.
BEST NEET COACHING CENTER | BEST IIT JEE COACHING INSTITUTE | BEST NEET & IIT JEE COACHING
https://www.cleariitmedical.com/p/ncert-solutions-for-class-7-science_94.html
https://www.cleariitmedical.com/
https://www.cleariitmedical.com/
https://www.cleariitmedical.com/p/ncert-solutions-for-class-7-science_94.html
true
7783647550433378923
UTF-8
Loaded All Posts Not found any posts VIEW ALL Readmore Reply Cancel reply Delete By Home PAGES POSTS View All RECOMMENDED FOR YOU LABEL ARCHIVE SEARCH ALL POSTS Not found any post match with your request Back Home Sunday Monday Tuesday Wednesday Thursday Friday Saturday Sun Mon Tue Wed Thu Fri Sat January February March April May June July August September October November December Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec just now 1 minute ago $$1$$ minutes ago 1 hour ago $$1$$ hours ago Yesterday $$1$$ days ago $$1$$ weeks ago more than 5 weeks ago Followers Follow THIS CONTENT IS PREMIUM Please share to unlock Copy All Code Select All Code All codes were copied to your clipboard Can not copy the codes / texts, please press [CTRL]+[C] (or CMD+C with Mac) to copy

STAY CONNECTED