Garbage In, Garbage Out — Class 6 Biological Science
'There is no such thing as 'away' — when we throw something away, it goes somewhere.'
1. Introduction
Every day, we generate garbage (waste) — from kitchen scraps to plastic bottles. What happens to this garbage after it leaves our home? How can we manage waste responsibly?
Why This Chapter Matters
- Understand the waste problem
- Learn to reduce, reuse, and recycle
- Environmental responsibility
- AP context: urban waste management, Swachh Bharat mission
2. Types of Waste
Biodegradable Waste
Waste that can be broken down by microorganisms (bacteria, fungi) into simpler, harmless substances.
| Biodegradable Waste | Time to Decompose |
|---|---|
| Vegetable peels | 1-2 weeks |
| Fruit scraps | 1-3 weeks |
| Egg shells | 1-2 months |
| Paper | 2-6 weeks |
| Cotton cloth | 2-5 months |
| Wood | 10-15 years |
| Leaves, grass | 2-4 weeks |
Non-Biodegradable Waste
Waste that cannot be broken down by microorganisms.
| Non-Biodegradable Waste | Time to Decompose |
|---|---|
| Plastic bag | 500-1000 years |
| Plastic bottle | 450 years |
| Glass bottle | 1 million years |
| Aluminium can | 200-500 years |
| Styrofoam | Never (effectively) |
| Nylon | 30-40 years |
| Battery | 100+ years (toxic!) |
Comparison
| Feature | Biodegradable | Non-Biodegradable |
|---|---|---|
| Decomposes naturally? | YES | NO |
| Time to decompose | Days to years | Hundreds to millions of years |
| Causes pollution? | Creates compost | Stays in environment |
| Examples | Food waste, paper, wood | Plastic, glass, metal |
3. Composting
Composting is the process of converting biodegradable waste into compost (a nutrient-rich soil-like material).
How to Make Compost
Traditional (Pit) Method:
- Dig a pit in the ground
- Layer biodegradable waste (kitchen scraps, leaves, grass)
- Cover with a thin layer of soil
- Sprinkle water to keep moist (not wet!)
- Turn the pile every 2-3 weeks for aeration
- In 2-3 months → dark, crumbly compost is ready
What to Compost
| YES (Compost This) | NO (Do NOT Compost) |
|---|---|
| Vegetable peels | Meat, fish (attracts pests) |
| Fruit scraps | Oily food |
| Egg shells | Dairy products (milk, cheese) |
| Tea leaves, coffee grounds | Diseased plants |
| Leaves, grass clippings | Plastic, glass, metal |
| Paper, cardboard (torn) | Synthetic fabrics |
| Wood ash (small amounts) | Coal ash |
4. Vermicomposting
Vermicomposting uses earthworms to speed up composting. The worms eat the waste and produce worm castings (vermicompost) — an excellent natural fertiliser.
How to Start Vermicomposting
- Take a container with small holes (for aeration and drainage)
- Layer: Sand → Soil → Biodegradable waste → Dry leaves
- Add red wiggler worms (Eisenia fetida — NOT garden earthworms)
- Keep the container in a shaded place
- Keep the contents moist (not wet)
- After 3-4 weeks: collect the compost
What Worms Need
- Moist (not wet) bedding
- Food waste (chopped small)
- Darkness (worms are sensitive to light)
- Temperatures between 15-30°C
Benefits of Vermicompost
- Rich in nutrients (N, P, K)
- Improves soil structure
- Increases water retention
- Natural fertiliser (no chemicals)
- Safe for plants and the environment
Worms to Use
- Best: Red wigglers (Eisenia fetida)
- Do NOT use: ordinary garden earthworms (they live deep in soil, not in compost)
'Vermicompost is called 'black gold' by gardeners — it is the best natural fertiliser you can make.'
5. Recycling
Recycling is processing used materials into new products.
What Can Be Recycled
| Material | What It Becomes |
|---|---|
| Paper | New paper, cardboard, egg trays |
| Glass | New glass bottles, jars |
| Plastic | New bottles, bags, furniture, fleece |
| Metal (aluminium) | New cans, foil |
| Steel | New cans, car parts |
The Recycling Process (Paper Example)
- Used paper is collected and sorted
- Mixed with water to make pulp
- Filtered and cleaned
- Pressed and dried into new paper sheets
- 'Recycling 1 ton of paper saves 17 trees!'
Benefits of Recycling
- Saves natural resources (trees, oil, minerals)
- Saves energy (making new from recycled uses less energy)
- Reduces landfill waste
- Reduces pollution
- Creates jobs
6. Reduce, Reuse, Recycle (The 3 R's)
The best way to manage waste is to not create it in the first place!
Reduce (Most Important)
Use LESS to create less waste.
| Instead of This | Do This |
|---|---|
| Buying bottled water | Use a reusable water bottle |
| Taking plastic bags from shops | Carry a cloth/jute bag |
| Printing unnecessary papers | Read on screen |
| Buying over-packaged items | Choose minimal packaging |
Reuse
Use items AGAIN instead of throwing them away.
| Single Use | Reuse Idea |
|---|---|
| Plastic bottle | Fill with water, use as plant waterer |
| Glass jar | Store spices, pulses |
| Old clothes | Cut into cleaning rags |
| Newspaper | Wrap gifts, clean windows |
| Tyre | Garden swing, planter |
Recycle
When you cannot reduce or reuse, recycle.
'Segregate waste at home: wet (kitchen waste) in one bin, dry (plastic, paper, metal) in another.'
7. Landfills
Landfills are large areas where garbage is dumped and buried.
Problems with Landfills
- Space: Landfills take up huge areas of land
- Leachate: Rainwater percolating through garbage creates toxic liquid that can pollute groundwater
- Methane: Decomposing waste produces methane (a greenhouse gas 25× stronger than CO₂)
- Odour: Landfills smell terrible
- Pests: Attracts rats, flies, birds
What Happens to AP's Garbage?
- Vijayawada: Waste is processed at a plant that generates electricity from garbage
- Visakhapatnam: GVMC (Greater Visakhapatnam Municipal Corporation) has waste-to-energy initiatives
- Many towns still rely on open dumping — a serious problem
8. AP Context: Waste Management
Vijayawada
- Vijayawada generates about 450+ tonnes of waste daily
- The city has a waste-to-energy plant that converts garbage into electricity
- Door-to-door waste collection is implemented
- Wet and dry waste segregation is promoted
Visakhapatnam
- Generates about 500+ tonnes of waste daily
- GVMC has composting facilities and recycling centres
- Visakhapatnam was ranked among the cleanest cities in India (Swachh Survekshan)
- Beach cleaning drives are regular
Challenges
- Rapid urbanisation → more waste
- Lack of segregation at source
- Limited landfill space
- Public awareness still growing
9. Common Mistakes — Fix Them Now
| # | Mistake | Correction |
|---|---|---|
| 1 | Thinking all waste is 'just garbage' | Waste can be COMPOSTED (biodegradable) or RECYCLED (non-biodegradable) |
| 2 | Putting all waste in one bin | Segregate: wet (kitchen) in green bin, dry (plastic/metal) in blue bin |
| 3 | Calling vermicomposting 'just composting' | Vermicomposting uses WORMS to break down waste faster and produce richer compost |
| 4 | Believing biodegradable plastic is harmless | Some biodegradable plastics still take years and leave microplastics |
| 5 | Throwing batteries in regular trash | Batteries contain toxic chemicals — they need SPECIAL disposal |
10. Exam Focus
Marks Blueprint
| Question Type | Marks | Topic |
|---|---|---|
| MCQ | 1 | Biodegradable vs non-biodegradable |
| Short answer | 2 | Composting / vermicomposting |
| Short answer | 2 | 3 R's (Reduce, Reuse, Recycle) |
| Long answer | 3 | Waste management methods |
| AP context | 3 | Waste management in Vijayawada/Visakhapatnam |
Quick Self-Test (5 Questions)
Q1: What is the difference between biodegradable and non-biodegradable waste?
<details><summary>Answer</summary>Biodegradable can be broken down by microorganisms (food waste, paper). Non-biodegradable cannot (plastic, glass, metal).</details>Q2: What is vermicomposting?
<details><summary>Answer</summary>Composting using earthworms (red wigglers) to break down organic waste into nutrient-rich fertiliser.</details>Q3: Name the three R's of waste management.
<details><summary>Answer</summary>Reduce (use less), Reuse (use again), Recycle (process into new products).</details>Q4: Why is plastic waste a major problem?
<details><summary>Answer</summary>Plastic is non-biodegradable — it takes 500-1000 years to decompose and pollutes land and oceans.</details>Q5: How is waste managed in Vijayawada?
<details><summary>Answer</summary>Door-to-door collection, waste segregation, and a waste-to-energy plant that converts garbage into electricity.</details>11. Chapter Summary
- Biodegradable: breaks down naturally (food, paper, wood)
- Non-biodegradable: does NOT break down (plastic, glass, metal)
- Composting: converting organic waste into compost naturally
- Vermicomposting: using red wiggler worms to make rich compost
- Recycling: processing waste into new products (paper, glass, metal, plastic)
- 3 R's: Reduce (best), Reuse (next best), Recycle (last resort)
- Landfills: harmful to environment — we should minimise what goes there
- AP waste management: Vijayawada (waste-to-energy), Visakhapatnam (composting, recycling)
'Every piece of garbage we create has an impact — by reducing, reusing, and recycling, we can make the Earth cleaner and greener for future generations.'
