Selina Solutions for Class 9 Biology Chapter 19 - Waste Generation and Management

Selina solutions are here to provide answers to all the questions appearing in the textbook right from the easy ones to the complicated ones. ICSE Class 9 solutions aims at presenting solved queries to the students taking into consideration the time factor in a student’s academic life.

Questions are persistent, whichever field of study it is. Answering, however, is an art. It is a great tool to assess the knowledge and level of information absorbed by the student. These skills of the students are assessed in examination through different types of questions such as application type of questions, multiple-choice questions, matching items from two different columns etc. This also helps the student to get an insight into his own preparations.

Selina solutions not only equips students with accurate answers to the textbook questions but also enables students to pick up the answering strategies which prove to be extremely beneficial and a powerful tactic to perform exceedingly well at the examinations.

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Access Answers of Biology Selina class 9 Chapter 19 – Waste Generation and Management

  1. How will you categorize the following under domestic and industrial wastes?

    Rags, used containers, old newspapers, mine tailing (left overs), flyash, kitchen waste, broken bricks.

    Solution:

    Domestic waste

    Industrial waste

    Rags

    mine tailing

    used containers

    flyash

    old newspapers

    broken bricks

    kitchen waste

  2. What is bagasse?

    Solution:

    It is the plant residue left after extracting the sugarcane juice. It is used as fire wood or in paper industry.

  3. Name any two categories of chemicals which are washed off as wastes from agricultural fields.

    Solution:

    The chemicals that are washed off as wastes from agricultural fields are – Pesticides and Fertilizers.

  4. What are the two portions into which the municipal sewage is separated?

    Solution:

    The two portions into which the municipal sewage is separated are:

    • Degradable part – capable of being broken down chemically into non-toxic parts
    • Non-degradable part – They are dumped and buried at safe places.
  5. In which category of wastes will you include the non-functioning discarded

    1. Mobile phones,
    2. Thermometers,
    3. Photocopying machines.

    Solution:

    The category of waste in which the non-functioning discarded mobile phones, thermometers and photocopying machines can be included is e-waste. E-waste is the abbreviation of electronic waste and consists of the discarded appliances using electricity.

  6. Name the three categories of wastes under segregation

    Solution:

    The three categories of wastes under segregation are:

    • Reusable
    • Degradable
    • Non-degradable
  7. Which categories of wastes require dumping?

    Solution:

    The categories of waste that requires dumping is the non-degradable waste.

  8. Is it true that composting is a useful method contributing in crop farming?

    Solution:

    Yes, it is true that composting is a useful method contributing in crop farming as composting means putting the waste organic matter to decay so that it can be used for fertilizing the agricultural land.

  9. What is sludge?

    Solution:

    Sludge is a solid precipitated material produced during second treatment of waste water (effluent) when it is pumped into oxidation ponds where the microbes oxidize the organic matter releasing carbon dioxide during the process, carried out in the Effluent Treatment Plants.

  10. Can incineration lead to certain kind of pollution/ Yes/No.

    Solution:

    Yes, incineration can lead to certain kind of pollution as during the process of incineration, fumes and harmful substances are released.

  11. Name two types of devices used for removing particulate air pollutants.

    Solution:

    The two types of devices used for removing particulate air pollutants are:

    • Scrubbers
    • Plate type electrostatic precipitators

Multiple Choice Type

  1. The most convenient reusable wastes are

    1. Old newspapers
    2. Broken glass
    3. Flyash
    4. Medical instruments

    Solution:

    a) Old newspapers

    They are common wastes that is recycled for its reuse in the paper industry.

  2. The most rapidly increasing and much harmful waste today is

    1. Plastics
    2. Pesticides
    3. Municipal sewage
    4. Electronic waste

    Solution:

    a) Plastics

    Plastic is a domestic waste that are usually given out from homes.

Very short answer type

  1. Name the following:

    1. The solid precipitated material produced during secondary treatment of the effluent, carried out in the Effluent Treatment Plants.
    2. The two types of devices commonly used for removing the particulate air pollutants.

    Solution:

    1. Sludge
    2. Scrubber, plate type electrostatic precipitators.
  2. Mention whether the following statements are true (T) or false (F).

    1. Some of the electronic wastes may contain valuable metals such as gold and copper-T/F
    2. Flyash is the gaseous waste of cement industry T/F
    3. Electricity is one of the primary needs of human society T/F

    Solution:

    1. The statement is true.
    2. The statement is true.
    3. The statement is false. Electricity is not one of the primary needs but secondary needs of human society.
  3. Match the items in Column I with as many items as possible in Column II.

    Column I Column I
    Cow dung Sugarcane
    Bagasse Raddiwalas
    Old newspapers Manure

    Solution:

    Column I Column I
    Cow dung Sugarcane , Manure
    Bagasse Sugarcane
    Old newspapers Raddiwalas ,Sugarcane

Short Answer Type

  1. Differentiate between degradable and non-degradable type of waste.

    Solution:

    The differences between degradable and non-degradable type of wastes are:

    Degradable Type of waste

    Non-degradable type of waste

    It is the waste that can be decomposed by micro-organisms

    These are the wastes that cannot be decomposed by micro-organisms

    Example – Paper, clothes

    Example – Plastic

  2. Give reasons for the following:

    1. Broken glass utensils are a kind of non-degradable waste.
    2. Landfills are coming up fast near large cities.
    3. Why is municipal sewage is first separated into degradable and non-degradable wastes?

    Solution:

    1. It is because they cannot be decomposed and disintegrated by living micro-organisms. They are required to be disposed in deeply dug pits so as to cause no harm. One of the applications of broken glass is that it can be used in glass industries in larger quantities after melting them.
    2. It is because of the tremendous growth in population and lack of using efficient and safe methods of disposal. The newer construction activities in new colonies produce large quantities of waste stones, broken bricks, pebbles and wastes from wood which are used as landfills observed in suburbs.
    3. It is because degradable wastes can be decomposed into non-toxic waste in septic tanks but non-degradable waste requires to be buried at safe places in order to avoid hazardous effects.

Long Answer Type

  1. Define electronic waste and list at least six items which come under this category.

    Solution:

    Electronic waste consists of discarded appliances that use electricity such as old computers, TVs, refrigerators, cell phones etc.

    Items under this category are:

    • Medical instruments
    • Lead acid batteries
    • Mobile phones
    • Refrigerators
    • Electronic toys
    • Fluorescent tubes
  2. List some of the common wastes produced in mining operation and mention how these can be reused.

    Solution:

    Some of the common wastes produced in mining operation and their reuse is as follows:

    • Dust
    • Coal
    • Iron
    • Copper
    • Zinc

    During the process of mining, a large quantity of waste material is generated which is referred to as mine tailing which is the residue or the left over. The application of mine tailing is that it can be mixed with materials for tile production and masonry cement.

  3. Describe the procedure usually used to produce compost

    Solution:

    Composting is the process of rotting and conversion of organic waste into manure and the product formed during the process of composting is called as compost.

    Method to prepare compost:

    • A trench of about 5m long, 1.5m wide and 1.5m deep is dug.
    • A layer of well mixed refuse and waste is spread in it for about 30cm thickness
    • This layer is fully wetted with a watery mixture of cow-dung and some mud.
    • A second layer of mixed refuse is spread over the first layer till the heap rises to project over the ground level by about half a metre.
    • Leave the set up undisturbed for around 3 months during which water is sprinkled at regular intervals
    • A trench is then opened and the material is taken out and rearranged in conical heaps and covered with a layer of soil.
    • Compost is ready after 50-60 days to be used in fields for cultivation or in garden flower beds etc.
  4. Describe the usefulness of incineration of wastes, and also mention the precautions required in it.

    Solution:

    Incineration is the disposal of waste by burning which causes the release of fumes and other toxic substances. The residue after incineration contains about 25% of wastes in the form of ash which should be deposited in landfills.

    Usefulness of incineration of wastes:

    • The left over ash occupies much lesser landfills.
    • Electricity can be generated from the heat released during burning.

    Precautions:

    • The process should be carried out at very high temperatures
    • Should be equipped with pollution control devices
    • Incinerators should be installed away from residential areas.

Selina Solutions for class 9 Biology Chapter 19 – Waste Generation and Management

ICSE Class 9 Biology Chapter 19 – Waste Generation and Management chapter is classified under Unit – VI of Biology textbook – Health & Hygiene. Health refers to the normal and healthy state of the body in all the three aspects namely – physical, mental and social wellness while Hygiene concerns with the conditions and practices in order to maintain health and prevent any chance of diseases.

The chapter – Waste Generation and Management intend to provide students with the basics on wastes, different sources of wastes, different categories of wastes, namely:

  • Domestic waste
  • Industrial waste
  • Agricultural waste
  • Municipal waste
  • E-waste

The chapter covers the following types of questions in order to assess students at different levels, they are:

  • Multiple-choice questions
  • Matching items from two given Columns
  • State whether statements are true or false
  • Very short answer type questions
  • Short answer type questions
  • Long answer type questions

List of subtopics covered in Chapter 19 – Waste Generation and Management

Number

Subtopic

19.1

What is a waste?

19.2

Categories of wastes

19.2.1

Domestic waste

19.2.2

Industrial waste

19.2.3

Agricultural waste

19.2.4

Municipal waste

19.2.5

e-waste

19.2.6

Science teaching and research laboratories wastes

19.3

Methods of safe disposal of wastes

19.3.1

Segregation

19.3.2

Dumping

19.3.3

Composting

19.3.4

Drainage

19.3.5

Treatment of effluents before discharge

19.3.6

Incineration

19.3.7

Scrubbers

19.3.8

Electrostatic precipitators

List of Exercise

Name of the exercise

Number of questions

Question Type

Page number

Progress Check

11

short

182, 184

Review questions

2

MCQ

184

5

short

184,185

4

long

185

Selina Solutions for class 9 Biology Chapter 19 – Waste Generation and Management

Waste generation and management is one of the topics covered under Health and Hygiene. Students are required to know about the basics of waste, different categories of wastes and the basis of classification of these wastes. Waste is a substance that is disposed of after primary use and is of no use.

The categories of wastes are as follows:

  • Domestic waste
  • Industrial waste
  • Agricultural waste
  • Municipal waste
  • E-waste

Some other topics that are discussed in this chapter are science teaching and research laboratories wastes, methods of safe disposal of wastes such as segregation, dumping, composting and drainage, treatment of effluents before discharge, incineration etc.

Key Features of Selina Solutions for class 9 Biology Chapter 19 – Waste Generation and Management

  • Selina Solutions are easily accessible, ready to use study tool
  • Easy to understand language
  • Step by step and detailed answers
  • Explanation provided for MCQs
  • Use of pointers wherever required
  • Crisp answers to questions

Frequently Asked Questions on Waste Generation and Management

What is bagasse?

It is the plant residue left after extracting the sugarcane juice. It is used as fire wood or in paper industry.

Name any two categories of chemicals which are washed off as wastes from agricultural fields?

The chemicals that are washed off as wastes from agricultural fields are – Pesticides and Fertilizers.

What are the two portions into which the municipal sewage is separated?

The two portions into which the municipal sewage is separated are:

  • Degradable part – capable of being broken down chemically into non-toxic parts
  • Non-degradable part – They are dumped and buried at safe places.

Name the three categories of wastes under segregation?

The three categories of wastes under segregation are:

  • Reusable
  • Degradable
  • Non-degradable

Which categories of wastes require dumping?

The categories of waste that requires dumping is the non-degradable waste.

What is sludge?

Sludge is a solid precipitated material produced during second treatment of waste water (effluent) when it is pumped into oxidation ponds where the microbes oxidize the organic matter releasing carbon dioxide during the process, carried out in the Effluent Treatment Plants.

Name two types of devices used for removing particulate air pollutants?

The two types of devices used for removing particulate air pollutants are:

  • Scrubbers
  • Plate type electrostatic precipitators