Chapter 22: Waste Management ♻️
A Comprehensive Guide for PSTET Paper-2 (Science)
Chapter Overview
| Section | Topic | PSTET Weightage | Page No. |
|:---:|:---|::---:|:---:|
| 22.1 | Types of Waste (Biodegradable and Non-biodegradable) | High | 2 |
| 22.2 | Methods of Waste Disposal (Landfills, Composting, Recycling, Vermicomposting) | High | 8 |
| 22.3 | Reduce, Reuse, and Recycle - The 3 R's | High | 16 |
| Practice Zone | MCQs & Pedagogical Questions | - | 22 |
Learning Objectives 🎯
After studying this chapter, you will be able to:
✅ Classify waste into biodegradable and non-biodegradable categories with examples
✅ Explain various methods of waste disposal—landfills, composting, vermicomposting, and recycling
✅ Apply the principles of Reduce, Reuse, and Recycle (3 R's) in daily life
✅ Analyze the environmental impacts of improper waste management
✅ Design simple waste management strategies for home and school
✅ Apply pedagogical strategies to teach waste management concepts effectively to upper primary students
Pedagogical Link 🔗
For Teachers: This chapter directly aligns with:
Class 6 Science NCERT Chapter 16: "Garbage In, Garbage Out"
Class 7 Science NCERT Chapter 18: "Wastewater Story"
Teaching Tips:
Begin with a "Waste Audit" activity—students collect and analyze one day's waste from their lunch boxes
Set up a classroom composting bin to demonstrate decomposition
Create a "Recycling Center" in the classroom with separate bins for different materials
Organize a "Best out of Waste" competition to encourage creative reuse
Connect to Swachh Bharat Mission and local waste management initiatives
Section 22.1: Types of Waste (Biodegradable and Non-biodegradable) 🗑️
Introduction
Everything we use eventually becomes waste. But not all waste is the same. Some waste decomposes naturally, while others persist in the environment for hundreds of years. Understanding the difference between these types of waste is the first step toward responsible waste management .
22.1.1 What is Waste?
Definition: Waste (or garbage) refers to any material that is no longer useful to the person who owns it and is thrown away .
Sources of Waste:
Households: Kitchen waste, packaging, paper, plastics, glass, metals
Schools: Paper, food waste, plastic wrappers, stationery waste
Industries: Chemical waste, packaging, scrap materials
Agriculture: Crop residues, animal waste
Hospitals: Biomedical waste (needles, bandages, expired medicines)
22.1.2 Classification of Waste
Waste can be classified based on its ability to decompose naturally :
A. Biodegradable Waste 🌱
Definition: Biodegradable waste is waste that can be broken down by microorganisms (bacteria, fungi) into simpler, harmless substances over time .
Characteristics:
Comes from living sources (plants or animals)
Decomposes naturally in the environment
Can be turned into useful products like compost
Does not accumulate in the environment indefinitely
Table 22.1: Examples of Biodegradable Waste
| Category | Examples |
|---|---|
| Kitchen Waste | Vegetable peels, fruit scraps, eggshells, tea leaves, coffee grounds |
| Food Waste | Leftover cooked food, stale bread, spoiled fruits/vegetables |
| Garden Waste | Grass clippings, leaves, twigs, flowers, weeds |
| Paper Products | Newspaper, notebooks, cardboard, tissue paper (uncoated) |
| Natural Fabrics | Cotton cloth, jute, wool (pure, not blended) |
| Animal Waste | Cow dung, goat droppings, food waste from animals |
| Other | Wood, sawdust, hair, nails (human/animal) |
Decomposition Time for Biodegradable Waste:
| Material | Approximate Decomposition Time |
|---|---|
| Vegetable scraps | 5 days – 1 month |
| Paper | 2–5 months |
| Cotton cloth | 5–6 months |
| Leaves | 6–12 months |
| Wood | 10–15 years |
B. Non-biodegradable Waste 🚫
Definition: Non-biodegradable waste is waste that cannot be broken down by microorganisms or takes an extremely long time (hundreds to thousands of years) to decompose .
Characteristics:
Often synthetic or man-made materials
Persist in the environment for centuries
Accumulate in landfills and oceans
Cause pollution and harm to wildlife
Table 22.2: Examples of Non-biodegradable Waste
| Category | Examples | Decomposition Time |
|---|---|---|
| Plastics | Plastic bags, bottles, containers, toys, packaging | 450–1000 years |
| Glass | Bottles, jars, broken glass | 1–2 million years |
| Metals | Aluminum cans, tin cans, scrap metal | 200–500 years |
| Rubber | Tyres, rubber bands, soles | 50–80 years |
| Synthetic Fibers | Polyester, nylon, acrylic clothing | 40–200 years |
| Electronic Waste (E-waste) | Old phones, computers, batteries, wires | Indefinite |
| Chemicals | Paints, pesticides, batteries, medicines | Indefinite |
| Thermocol/Styrofoam | Packaging material, disposable cups | 500+ years |
📝 PSTET Note: Some materials like tetra packs (juice/milk cartons) are multi-layered—they contain paper (biodegradable), plastic, and aluminum (non-biodegradable). This makes recycling them difficult .
22.1.3 Comparison: Biodegradable vs. Non-biodegradable Waste
Table 22.3: Biodegradable vs. Non-biodegradable Waste
| Feature | Biodegradable Waste | Non-biodegradable Waste |
|---|---|---|
| Decomposition | Can be decomposed by microorganisms | Cannot be decomposed by microorganisms |
| Time to Decompose | Days to years (relatively short) | Decades to millions of years (very long) |
| Source | Mostly from living organisms | Mostly synthetic/man-made |
| Effect on Environment | Can be turned into useful products; minimal harm if managed properly | Accumulates; causes pollution; harms wildlife |
| Examples | Vegetable peels, paper, cotton, wood | Plastic, glass, metal, e-waste |
| Management Method | Composting, vermicomposting, biogas | Recycling, landfilling, incineration |
22.1.4 Why This Classification Matters
Understanding the difference between biodegradable and non-biodegradable waste is crucial because:
| Reason | Explanation |
|---|---|
| Appropriate Disposal | Biodegradable waste can be composted; non-biodegradable needs recycling or landfilling |
| Environmental Impact | Non-biodegradable waste persists and causes long-term pollution |
| Resource Recovery | Non-biodegradable materials (metals, glass, plastic) can be recycled into new products |
| Health Hazards | Improper disposal of non-biodegradable waste (especially chemicals/e-waste) releases toxins |
| Wildlife Protection | Animals often ingest plastic waste, leading to death |
22.1.5 Classroom Activity: Waste Sorting Game
| Step | Procedure |
|---|---|
| 1 | Collect various waste items (clean and safe to handle) |
| 2 | Provide two bins labeled "Biodegradable" and "Non-biodegradable" |
| 3 | Students sort items into correct bins |
| 4 | Discuss any items that are difficult to classify (e.g., tetra packs) |
22.1.6 Pedagogical Implications
| Teaching Strategy | Description | PSTET Focus |
|---|---|---|
| "Bring Your Garbage" Day | Students bring one piece of waste from home; classify together | Real-world connection |
| Decomposition Experiment | Bury different materials in soil; observe after weeks/months | Long-term observation |
| Photo Sorting | Use pictures of waste items for quick classification | Visual learning |
| "Why This Matters" Discussion | Discuss what happens to each type of waste in nature | Environmental awareness |
Section 22.2: Methods of Waste Disposal (Landfills, Composting, Recycling, Vermicomposting) 🚛
Introduction
Once waste is generated, it needs to be managed properly. Different methods are used for different types of waste. Some methods focus on safe disposal, while others aim to recover resources and reduce environmental impact .
22.2.1 Overview of Waste Disposal Methods
Table 22.4: Major Waste Disposal Methods
| Method | Best For | Process Summary | Advantages | Disadvantages |
|---|---|---|---|---|
| Landfills | Mixed waste (especially non-recyclable) | Waste buried in lined pits | Handles large volumes; relatively simple | Land use; leachate; methane emissions |
| Composting | Biodegradable waste | Decomposition by microorganisms in presence of oxygen | Produces useful compost; reduces landfill load | Requires space; odor if not managed |
| Vermicomposting | Biodegradable waste | Decomposition using earthworms | Produces nutrient-rich compost; faster than composting | Requires care for worms; sensitive to conditions |
| Recycling | Non-biodegradable materials (plastic, glass, metal, paper) | Reprocessing materials to make new products | Conserves resources; saves energy; reduces pollution | Requires segregation; infrastructure needed |
| Incineration | Medical waste, hazardous waste | Burning at high temperatures | Reduces volume; can generate energy | Air pollution; expensive |
| Biogas Generation | Organic waste | Anaerobic digestion produces methane for fuel | Produces energy; reduces waste | Requires sealed digester |
| Pyrolysis | Certain plastics, tyres | Thermal decomposition in absence of oxygen | Recovers materials; less pollution | Complex technology |
22.2.2 Landfills 🏞️
Definition: A landfill is a carefully designed structure built into or on top of the ground, used for disposing of waste by burying it .
Modern Sanitary Landfill Design:
| Component | Purpose |
|---|---|
| Liner System | Clay or plastic liner prevents leachate from contaminating groundwater |
| Leachate Collection System | Pipes collect liquid that percolates through waste for treatment |
| Gas Collection System | Captures methane (produced by decomposing waste) for energy or flaring |
| Daily Cover | Soil or alternative material covers waste each day to control pests and odor |
| Final Cover | When landfill is full, it's capped with impermeable layer and soil for vegetation |
| Monitoring Wells | Check groundwater quality around landfill |
📝 PSTET Note: Open dumps (uncontrolled, unlined pits) are NOT the same as sanitary landfills and are illegal in many countries due to environmental and health hazards.
Problems with Landfills:
Land scarcity: Requires large areas of land
Leachate: If liners fail, toxic liquid pollutes groundwater
Methane emissions: Greenhouse gas contributes to climate change
Litter and pests: Wind-blown litter, rats, flies
Long-term liability: Landfills require monitoring for decades after closure
22.2.3 Composting 🍂
Definition: Composting is the natural process of decomposition of organic waste by microorganisms (bacteria, fungi) in the presence of oxygen, producing a nutrient-rich material called compost or humus .
The Composting Process:
| Stage | What Happens |
|---|---|
| 1. Collection | Biodegradable waste (kitchen scraps, leaves, garden waste) is collected |
| 2. Segregation | Non-biodegradable items removed |
| 3. Pile/Bin Creation | Waste layered in a compost bin or pile |
| 4. Decomposition | Microorganisms break down organic matter; pile heats up |
| 5. Turning | Pile is turned regularly to provide oxygen |
| 6. Maturation | Material cools and stabilizes; becomes dark, crumbly compost |
| 7. Use | Compost added to soil as fertilizer |
Materials for Composting:
| Green Materials (Nitrogen-rich) | Brown Materials (Carbon-rich) |
|---|---|
| Vegetable and fruit scraps | Dry leaves |
| Grass clippings | Straw/hay |
| Coffee grounds | Sawdust |
| Tea leaves | Shredded paper |
| Fresh plant trimmings | Cardboard (non-glossy) |
| Eggshells (crushed) | Wood chips |
What NOT to Compost:
Meat, fish, bones (attract pests, smell)
Dairy products (attract pests)
Oily/greasy food (slow decomposition)
Diseased plants (spread disease)
Pet waste (may contain pathogens)
Non-biodegradable items
Benefits of Composting:
| Benefit | Description |
|---|---|
| Reduces Landfill Waste | Organic waste diverted from landfills |
| Produces Free Fertilizer | Compost enriches soil, reduces need for chemical fertilizers |
| Improves Soil Health | Adds organic matter, improves water retention, aeration |
| Reduces Methane | Landfill methane from organics is avoided |
| Closes Nutrient Loop | Nutrients return to soil instead of being lost |
22.2.4 Vermicomposting
Definition: Vermicomposting is the process of using earthworms to decompose organic waste into nutrient-rich compost (vermicompost) .
How It Works:
| Component | Role |
|---|---|
| Earthworms (e.g., Eisenia fetida - Red Wigglers) | Eat organic waste; excrete castings (vermicompost) |
| Bedding | Moist material (shredded newspaper, coconut coir) for worms to live in |
| Organic Waste | Kitchen scraps, vegetable peels, etc. |
| Vermicompost | Worm castings—rich in nutrients, beneficial microbes |
Advantages of Vermicomposting over Regular Composting:
| Feature | Vermicomposting | Regular Composting |
|---|---|---|
| Speed | Faster (worms accelerate decomposition) | Slower |
| Nutrient Content | Higher (worm castings are nutrient-dense) | Good |
| Space Required | Can be done in small containers (indoor) | Needs more space |
| Labor | Minimal (worms do the work) | Needs turning |
| Temperature | Works at lower temperatures | Needs higher temperatures |
How to Make a Simple Vermicompost Bin:
| Step | Instructions |
|---|---|
| 1 | Take a plastic bin with lid; drill small holes for aeration |
| 2 | Add bedding (shredded newspaper, moistened) |
| 3 | Add a handful of soil (provides grit for worm digestion) |
| 4 | Introduce red wiggler worms (500-1000 for small bin) |
| 5 | Add kitchen waste in small amounts, covered with bedding |
| 6 | Keep bin moist (like a wrung-out sponge) but not wet |
| 7 | Harvest compost after 2-3 months; worms migrate to fresh food |
22.2.5 Recycling ♻️
Definition: Recycling is the process of collecting and processing materials that would otherwise be thrown away as trash and turning them into new products .
Materials Commonly Recycled:
| Material | Recycling Process | New Products |
|---|---|---|
| Paper | Pulped, cleaned, reformed | Newspaper, cardboard, tissue paper, stationery |
| Glass | Crushed (cullet), melted, molded | New bottles, jars, fiberglass |
| Aluminum | Melted, reformed | Cans, foil, car parts |
| Steel/Tin | Shredded, melted | New cans, construction materials |
| Plastic | Sorted, shredded, melted, pelletized | Bottles, containers, clothing (polyester), furniture |
| Electronics (E-waste) | Dismantled, components separated | Recovered metals, plastics for new electronics |
Benefits of Recycling:
| Benefit | Impact |
|---|---|
| Conserves Natural Resources | Reduces need to mine, log, extract raw materials |
| Saves Energy | Recycling aluminum saves 95% energy vs. new production |
| Reduces Pollution | Less mining, manufacturing pollution |
| Reduces Landfill Waste | Diverts materials from landfills |
| Creates Jobs | Recycling industry employs millions |
The Recycling Symbol:
♻️ with a number inside (1-7) indicates the type of plastic
1-PETE (polyethylene terephthalate): soft drink bottles
2-HDPE (high-density polyethylene): milk jugs, detergent bottles
3-PVC (polyvinyl chloride): pipes, packaging
4-LDPE (low-density polyethylene): plastic bags, cling wrap
5-PP (polypropylene): bottle caps, straws, yogurt containers
6-PS (polystyrene): Styrofoam, disposable cups
7-Other (mixed or other plastics)
22.2.6 Comparison of Waste Disposal Methods
Table 22.5: Summary of Waste Disposal Methods
| Method | Type of Waste | End Product | Environmental Impact | Cost |
|---|---|---|---|---|
| Landfill | Mixed waste | Buried waste | High (leachate, methane) | Medium |
| Composting | Biodegradable | Compost (soil conditioner) | Low (beneficial) | Low |
| Vermicomposting | Biodegradable | Vermicompost (nutrient-rich) | Very low (beneficial) | Low |
| Recycling | Non-biodegradable (paper, plastic, glass, metal) | New products | Low (saves resources) | Medium |
| Incineration | Medical, hazardous | Ash, energy | High (air pollution) | High |
| Biogas | Organic waste | Methane (fuel), slurry | Low (beneficial) | Medium |
22.2.7 Waste Management Hierarchy
The waste management hierarchy prioritizes the most environmentally sound methods:
┌─────────────────┐
│ REDUCE │ ← Most Preferred
├─────────────────┤
│ REUSE │
├─────────────────┤
│ RECYCLE │
├─────────────────┤
│ RECOVER │ (e.g., energy from waste)
├─────────────────┤
│ DISPOSE │ (Landfill) ← Least Preferred
└─────────────────┘22.2.8 Pedagogical Implications
| Teaching Strategy | Description | PSTET Focus |
|---|---|---|
| Classroom Composting | Set up small compost bin to observe decomposition | Hands-on learning |
| Vermicomposting Station | Maintain worm bin in classroom | Long-term engagement |
| Recycling Center Visit | Arrange trip to local recycling facility | Real-world connection |
| "Where Does It Go?" Project | Track waste from home to final disposal | Systems thinking |
Section 22.3: Reduce, Reuse, and Recycle - The 3 R's 🔄
Introduction
The most effective way to manage waste is to reduce the amount we create in the first place. The 3 R's—Reduce, Reuse, Recycle—provide a simple but powerful framework for minimizing waste and conserving resources .
22.3.1 The 3 R's Hierarchy
Table 22.6: The 3 R's in Order of Priority
| R | Principle | Meaning | Examples |
|---|---|---|---|
| 1. REDUCE | Prevent waste in the first place | Use less; buy less; choose products with less packaging | • Carry cloth bags, refuse plastic bags • Buy in bulk to reduce packaging • Avoid single-use items • Print double-sided • Buy only what you need |
| 2. REUSE | Use items again for the same or different purpose | Extend life of products; repair instead of replace | • Refill water bottles • Use containers for storage • Donate old clothes/toys • Use both sides of paper • Repair broken items |
| 3. RECYCLE | Turn waste into new products | Process materials to make new things | • Separate waste for recycling • Buy recycled products • Recycle paper, glass, metal, plastic |
22.3.2 Detailed Explanation of Each R
A. REDUCE (Most Important)
Why It's First: The best waste is the waste that never gets created. Reducing consumption saves resources, energy, and prevents pollution at the source .
Ways to Reduce:
| Category | Actions |
|---|---|
| Shopping | • Carry reusable cloth bags • Avoid products with excessive packaging • Buy in bulk (less packaging per item) • Choose products with minimal or recyclable packaging |
| Food | • Plan meals to avoid food waste • Buy only what you need • Compost unavoidable food scraps • Carry reusable water bottle and lunch box |
| Paper | • Print double-sided • Use electronic documents when possible • Read newspapers/magazines online |
| Energy/Water | • Turn off lights, fans when not in use • Fix leaking taps • Take shorter showers |
| General | • Avoid single-use items (straws, cutlery, plates) • Say "no" to plastic bags • Borrow or rent items used infrequently |
B. REUSE
Definition: Reusing means using an item again for the same purpose (refilling a bottle) or finding a new purpose for it (using a jar as a storage container) .
Ways to Reuse:
| Category | Actions |
|---|---|
| Containers | • Wash and reuse glass jars for storage • Refill plastic bottles (check safety—not all are safe for repeated use) • Use ice cream containers for leftovers |
| Clothing/Textiles | • Donate old clothes to charity • Pass on to younger siblings/relatives • Use old t-shirts as cleaning rags • Make quilts from old fabric |
| Paper | • Use both sides of paper for notes/drafts • Use old envelopes for shopping lists • Wrapping paper can be reused |
| Electronics | • Repair instead of replace • Donate working old phones/computers • Sell or give away items no longer needed |
| Furniture | • Refurbish/repaint old furniture • Donate to schools or charities |
| Creative Reuse | • "Best out of waste" projects (e.g., bottle planters, tin can pencil holders) |
C. RECYCLE
Definition: Recycling is processing used materials into new products to prevent waste of potentially useful materials .
The Recycling Loop:
Consumer → Discards product → Collection → Sorting → Processing → Manufacturing → New product → Consumer
What Can Be Recycled:
| Material | Preparation | Notes |
|---|---|---|
| Paper | Keep clean and dry; remove plastic windows from envelopes | Staples OK; wet paper cannot be recycled |
| Glass | Rinse; remove lids; separate by color if required | Broken glass accepted; ceramics not |
| Plastic | Rinse; check recycling number (1-7) | Not all plastics accepted locally |
| Aluminum | Rinse cans; crush if possible | Highly recyclable (95% energy saving) |
| Steel/Tin | Rinse food cans | Magnets separate steel from other waste |
| Electronics | Take to designated e-waste collection points | Contains hazardous materials |
📝 PSTET Note: Recycling should not be seen as the first solution—it requires energy and resources. Reducing and reusing are more sustainable than recycling .
22.3.3 The 3 R's in Action: Examples
| Item | REDUCE | REUSE | RECYCLE |
|---|---|---|---|
| Plastic Water Bottle | Carry reusable bottle; avoid buying bottled water | Refill reusable bottle (not single-use plastic) | Recycle the bottle if no alternative |
| Shopping Bags | Refuse plastic bags; carry cloth bag | Use cloth bag repeatedly | Recycle plastic bags (if clean) at designated points |
| Paper | Print double-sided; read online | Use scrap paper for notes | Recycle paper in paper bin |
| Food Waste | Buy only what you need; meal plan | Use leftovers for next meal | Compost unavoidable scraps |
| Old Mobile Phone | Buy only when needed; consider if upgrade necessary | Donate to someone who can use it | Recycle at e-waste facility |
22.3.4 The 3 R's and Sustainable Development
The 3 R's contribute directly to several Sustainable Development Goals (SDGs):
| SDG | Connection to 3 R's |
|---|---|
| SDG 12: Responsible Consumption and Production | Core principle—reduce consumption, recycle materials |
| SDG 13: Climate Action | Reduces emissions from production and waste decomposition |
| SDG 14: Life Below Water | Reduces plastic pollution in oceans |
| SDG 15: Life on Land | Reduces landfill burden, protects ecosystems |
22.3.5 Extended 5 R's Framework
Some educators use an expanded framework with 5 R's:
| R | Meaning | Description |
|---|---|---|
| Refuse | Say no to what you don't need | Refuse plastic straws, bags, single-use items |
| Reduce | Use less of what you need | Buy less, choose minimal packaging |
| Reuse | Use items again | Repair, repurpose, donate |
| Rot | Compost organic waste | Return nutrients to soil |
| Recycle | Process materials into new products | Only after other options exhausted |
22.3.6 The Circular Economy Concept
The 3 R's are part of a larger shift toward a circular economy—an economic system aimed at eliminating waste and the continual use of resources .
| Linear Economy | Circular Economy |
|---|---|
| Take → Make → Use → Dispose | Reduce → Reuse → Recycle → Regenerate |
| Resources extracted, used briefly, thrown away | Resources kept in use as long as possible |
| Waste is inevitable | Waste is designed out |
| Products become waste | Products become resources again |
22.3.7 Individual Responsibility and Collective Action
| Individual Actions | Community/Policy Actions |
|---|---|
| Practice 3 R's at home and school | Separate waste collection systems |
| Carry reusable bags, bottles | Awareness campaigns |
| Compost kitchen waste | Ban on single-use plastics |
| Buy recycled products | Extended Producer Responsibility (EPR) |
| Avoid over-packaged goods | Incentives for waste reduction |
22.3.8 Pedagogical Implications
| Teaching Strategy | Description | PSTET Focus |
|---|---|---|
| "3 R's Pledge" | Students take pledge to practice 3 R's at home | Commitment building |
| "Best out of Waste" Competition | Create useful items from waste materials | Creative application |
| Waste-Free Lunch Challenge | Aim for zero waste lunch one day a week | Practical application |
| 3 R's Audit | Audit classroom waste and suggest improvements | Problem-solving |
Chapter Summary: Key Points for Revision 📝
Quick Revision Table
| Topic | Key Points | Common PSTET Questions |
|---|---|---|
| Biodegradable Waste | Can be decomposed by microorganisms; from living sources; examples: vegetable peels, paper, cotton | Define biodegradable waste with examples |
| Non-biodegradable Waste | Cannot be decomposed; synthetic; examples: plastic, glass, metal, e-waste | Define non-biodegradable waste with examples |
| Decomposition Time | Paper: 2-5 months; Plastic: 450-1000 years; Glass: 1-2 million years | Which waste takes longest to decompose? |
| Landfills | Engineered pits with liners, leachate collection, gas recovery | What is a sanitary landfill? |
| Composting | Aerobic decomposition of organic waste; produces humus | How is compost made? |
| Vermicomposting | Using earthworms to decompose waste; produces nutrient-rich vermicompost | What is vermicomposting? |
| Recycling | Processing waste into new products; saves energy and resources | Benefits of recycling |
| 3 R's (Priority) | 1. Reduce, 2. Reuse, 3. Recycle | Explain the 3 R's in correct order |
| Reduce | Prevent waste; buy less; choose less packaging | Examples of reducing waste |
| Reuse | Use items again; repair; repurpose | Examples of reusing |
| Recycle | Turn waste into new products | What can be recycled? |
Practice Zone: PSTET-Style Questions 🎯
Content-Based MCQs
Q1. Which of the following is an example of biodegradable waste?
a) Plastic bottle
b) Glass jar
c) Vegetable peels
d) Aluminum can
Q2. Approximately how long does it take for a plastic bottle to decompose?
a) 5-10 years
b) 50-100 years
c) 450-1000 years
d) 1-2 million years
Q3. The process of using earthworms to decompose organic waste is called:
a) Composting
b) Vermicomposting
c) Recycling
d) Landfilling
Q4. Which of the following is NOT a benefit of recycling?
a) Conserves natural resources
b) Saves energy
c) Increases landfill waste
d) Reduces pollution
Q5. The correct order of the 3 R's from most to least preferred is:
a) Recycle → Reuse → Reduce
b) Reduce → Reuse → Recycle
c) Reuse → Reduce → Recycle
d) Recycle → Reduce → Reuse
Q6. Which material has the longest decomposition time?
a) Paper
b) Cotton cloth
c) Glass
d) Wood
Q7. In a sanitary landfill, the liquid that percolates through waste is called:
a) Methane
b) Leachate
c) Compost
d) Slurry
Q8. Which of the following is an example of REUSE?
a) Buying products with less packaging
b) Using a cloth bag instead of plastic
c) Refilling a water bottle
d) Recycling newspapers
Q9. Tetra packs (juice cartons) are difficult to recycle because:
a) They are made of paper only
b) They are made of multi-layered materials (paper + plastic + aluminum)
c) They are too small
d) They are biodegradable
Q10. The plastic recycling symbol with number 1 indicates:
a) HDPE
b) PVC
c) PETE (polyethylene terephthalate)
d) LDPE
Pedagogical MCQs
Q11. A teacher wants to teach students about biodegradable vs. non-biodegradable waste. The best activity would be:
a) Give definitions to memorize
b) Show a video about waste
c) Have students sort actual waste items into two bins
d) Draw diagrams on board
Q12. To demonstrate composting in the classroom, the most practical approach is:
a) Read about composting from textbook
b) Set up a small compost bin with kitchen scraps and observe over weeks
c) Show pictures of compost
d) Take students to a landfill
Q13. A student asks, "Why should I bother recycling? It's just a drop in the ocean." The best explanation is:
a) "Because the school says so"
b) "Every drop counts—if everyone thinks that way, nothing will change. Your actions inspire others."
c) "Recycling is mandatory"
d) Ignore the question
Q14. While teaching the 3 R's, a teacher organizes a "Best out of Waste" competition. This promotes:
a) Rote learning
b) Creative thinking and application of reuse concept
c) Memorization of waste types
d) Competitive spirit only
Q15. The most effective way to teach the environmental impact of plastic waste is:
a) Show statistics
b) Show images/videos of animals affected by plastic pollution
c) Give a lecture
d) Read from textbook
Answer Key with Explanations
| Q.No. | Answer | Explanation |
|---|---|---|
| 1 | c) Vegetable peels | Vegetable peels are biodegradable; plastic, glass, metal are non-biodegradable |
| 2 | c) 450-1000 years | Plastic takes 450-1000 years to decompose |
| 3 | b) Vermicomposting | Vermicomposting uses earthworms to decompose waste |
| 4 | c) Increases landfill waste | Recycling reduces landfill waste, not increases it |
| 5 | b) Reduce → Reuse → Recycle | This is the correct priority order |
| 6 | c) Glass | Glass takes 1-2 million years to decompose |
| 7 | b) Leachate | Leachate is the liquid that drains from landfills |
| 8 | c) Refilling a water bottle | Reuse means using again; refilling is reuse |
| 9 | b) Multi-layered materials | Tetra packs have paper, plastic, aluminum layers |
| 10 | c) PETE | Number 1 = PETE (polyethylene terephthalate) |
| 11 | c) Hands-on sorting | Direct experience is most effective |
| 12 | b) Hands-on composting | Long-term observation makes learning real |
| 13 | b) Empowering explanation | Encourages responsibility and collective action |
| 14 | b) Creative application | "Best out of waste" directly teaches reuse |
| 15 | b) Visual impact | Emotional connection drives behavior change |
Pedagogical Reflection for Teachers 🤔
Think-Pair-Share Activity:
Think: How would you convince students that their individual actions on waste matter, even when they see others littering?
Pair: Discuss with a colleague how you would set up a "Zero Waste Classroom" challenge with students.
Share: Design a 15-minute activity to teach the difference between Reduce, Reuse, and Recycle using everyday examples.
NCERT Textbook Linkages 📚
| Class | Chapter | Topic |
|---|---|---|
| Class 6 | Chapter 16 | Garbage In, Garbage Out |
| Class 7 | Chapter 18 | Wastewater Story |
