Environment and Sustainability (4300003) - Winter 2021 Solution

Question 1 (Any Seven) [14 marks]

#

1. Define the terms: ‘Ecology’ and ‘Ecosystem’.

#

Answer: Ecology is the scientific study of relationships between living organisms and their environment. Ecosystem is a biological community of interacting organisms and their physical environment functioning as a unit.

Table:

• Biotic components: Living organisms in the system
• Abiotic components: Non-living factors like air, water, soil

Mnemonic: “Every Component Lives Together” (Ecology Creates Living Together)

2. Define the terms: ‘Pollution’ and ‘Pollutant’.

#

Answer: Pollution is the introduction of harmful substances into the environment causing adverse effects. Pollutant is any substance that causes pollution when present in excessive amounts.

Table:

• Primary pollutants: Directly emitted substances
• Secondary pollutants: Formed by reactions in atmosphere

Mnemonic: “Pollution Produces Problems” (Pollutants Produce Problems)

3. What is noise pollution? What is unit of intensity of sound?

#

Answer: Noise pollution is unwanted or excessive sound that disrupts human activities and harms living beings. The unit of sound intensity is decibel (dB).

Table:

• Threshold of hearing: 0 dB
• Threshold of pain: 120 dB

Mnemonic: “Decibels Determine Damage” (dB Determines Damage)

4. What is solid waste management? Give its objectives.

#

Answer: Solid waste management is systematic handling of waste from generation to final disposal to minimize environmental impact and protect public health.

Objectives:

• Public health protection: Prevent disease transmission
• Environmental protection: Reduce pollution and contamination
• Resource recovery: Recycle and reuse materials
• Cost effectiveness: Economic waste handling

Mnemonic: “People Expect Resource Conservation” (Protection, Environment, Resource, Cost)

5. Enlist types of solar cells.

#

Answer: Solar cells convert sunlight directly into electricity through photovoltaic effect.

Table:

• Silicon-based: Most common type
• Non-silicon: Emerging technologies

Mnemonic: “Most People Think” (Mono, Poly, Thin-film)

6. What is climate change?

#

Answer: Climate change refers to long-term shifts in global temperatures and weather patterns, primarily caused by human activities and greenhouse gas emissions.

Causes:

• Greenhouse gases: CO₂, CH₄, N₂O emissions
• Deforestation: Reduced carbon absorption
• Industrial activities: Fossil fuel burning

Effects:

• Rising temperatures: Global warming
• Sea level rise: Melting ice caps

Mnemonic: “Change Creates Consequences” (Climate Change Creates Consequences)

7. What is C.F.C?

#

Answer: CFC (Chlorofluorocarbon) are synthetic compounds containing carbon, fluorine, and chlorine atoms, previously used in refrigeration and aerosols.

Properties:

• Ozone depleting: Destroys stratospheric ozone
• Greenhouse gas: Contributes to global warming
• Stable compounds: Long atmospheric lifetime
• Montreal Protocol: International ban agreement

Mnemonic: “Chlorine Fluorine Carbon” (CFC components)

8. Give advantages of ISO-14000.

#

Answer: ISO 14000 is international standard for environmental management systems.

Advantages:

• Environmental compliance: Meet legal requirements
• Cost reduction: Efficient resource use
• Market advantage: Enhanced company image
• Risk management: Prevent environmental incidents

Table:

Mnemonic: “Companies Gain Market Recognition” (Compliance, Cost, Market, Risk)

9. Enlist various Acts related to environment in India.

#

Answer: India has comprehensive environmental legislation framework.

Major Acts:

• Air Act (1981): Air pollution control
• Water Act (1974): Water pollution prevention
• Environment Protection Act (1986): Comprehensive environmental law
• Wildlife Protection Act (1972): Biodiversity conservation
• Forest Conservation Act (1980): Forest protection

Mnemonic: “All Water Environments Wildlife Forests” (AWEWF)

10. Enlist various methods of rainwater harvesting.

#

Answer: Rainwater harvesting collects and stores rainwater for future use.

Methods:

• Rooftop harvesting: Direct collection from roofs
• Surface runoff harvesting: From ground surfaces
• Recharge pits: Groundwater recharging
• Check dams: Stream water collection

Table:

Mnemonic: “Roofs Surface Recharge Check” (RSRC)

Question 2(a) [3 marks]

#

Write short note on: Food chain.

#

Answer: Food chain represents the flow of energy and nutrients through different trophic levels in an ecosystem.

graph LR
    A[Producers<br/>Plants] --> B[Primary Consumers<br/>Herbivores]
    B --> C[Secondary Consumers<br/>Carnivores]
    C --> D[Tertiary Consumers<br/>Top Predators]
    D --> E[Decomposers<br/>Bacteria/Fungi]

• Energy transfer: Only 10% passes to next level
• Biomass pyramid: Decreases at higher levels

Mnemonic: “Plants Provide Primary Power” (Producer to Predator Path)

OR

#

Explain factors affecting ecosystem.

#

Answer: Ecosystems are influenced by various biotic and abiotic factors.

Factors:

• Climate factors: Temperature, rainfall, humidity
• Soil factors: pH, nutrients, texture
• Biotic factors: Species interactions, population density
• Human factors: Pollution, habitat destruction

Table:

Mnemonic: “Climate Soil Biology Humans” (CSBH)

Question 2(b) [3 marks]

#

Write short note on: Virtual water

#

Answer: Virtual water is the hidden water used in production of goods and services, representing total water consumption in supply chain.

Examples:

• 1 kg wheat: 1,300 liters virtual water

• 1 kg beef: 15,400 liters virtual water

• 1 cotton t-shirt: 2,700 liters virtual water

• Water footprint: Total virtual water consumption

• Trade implications: Water-rich countries export virtual water

Mnemonic: “Virtual Water Worldwide” (VWW)

OR

#

What is biodiversity? Give its types.

#

Answer: Biodiversity is the variety of life forms at genetic, species, and ecosystem levels on Earth.

Types:

• Genetic diversity: Variation within species
• Species diversity: Number of different species
• Ecosystem diversity: Variety of habitats and communities

mindmap
  root((Biodiversity))
    Genetic
      DNA variation
      Population genetics
    Species
      Flora
      Fauna
    Ecosystem
      Terrestrial
      Aquatic

Mnemonic: “Genes Species Ecosystems” (GSE)

Question 2(c) [4 marks]

#

Explain: Carbon cycle

#

Answer: Carbon cycle describes the movement of carbon through Earth’s atmosphere, land, water, and organisms.

graph TB
    A[Atmospheric CO₂] --> B[Photosynthesis]
    B --> C[Plant Biomass]
    C --> D[Animal Consumption]
    D --> A
    C --> E[Decomposition]
    E --> A
    F[Fossil Fuels] --> A
    A --> G[Ocean Absorption]
    G --> H[Marine Life]

Processes:

• Photosynthesis: CO₂ absorption by plants
• Respiration: CO₂ release by organisms
• Decomposition: Carbon return to atmosphere
• Ocean exchange: CO₂ dissolution in seawater

Mnemonic: “Plants Breathe, Die, Ocean” (PBDO)

OR

#

Draw and explain the hydrologic cycle

#

Answer: Hydrologic cycle is the continuous movement of water through atmosphere, land, and oceans.

graph TB
    A[Ocean] --> B[Evaporation]
    B --> C[Water Vapor]
    C --> D[Condensation]
    D --> E[Clouds]
    E --> F[Precipitation]
    F --> G[Surface Runoff]
    F --> H[Infiltration]
    G --> A
    H --> I[Groundwater]
    I --> A

Processes:

• Evaporation: Water to vapor conversion
• Condensation: Vapor to liquid conversion
• Precipitation: Rain, snow formation
• Infiltration: Groundwater recharge

Mnemonic: “Every Cloud Produces Rain” (ECPR)

Question 2(d) [4 marks]

#

Enlist equipments used to control air pollution and explain any one.

#

Answer: Air pollution control equipment removes pollutants from industrial emissions.

Equipment List:

• Cyclone separators: Particulate removal
• Electrostatic precipitators: Fine particle collection
• Bag filters: Fabric filtration
• Scrubbers: Gas absorption

Electrostatic Precipitator:

• Charging: Particles acquire electric charge
• Collection: Charged particles attracted to plates
• Efficiency: 99% removal of fine particles

Mnemonic: “Charge Collect Clean” (CCC)

OR

#

Enlist the types of environmental pollution and give the effects of noise pollution

#

Answer: Environmental pollution types:

• Air pollution: Atmospheric contamination
• Water pollution: Aquatic contamination
• Soil pollution: Land contamination
• Noise pollution: Sound contamination

Noise Pollution Effects:

• Health effects: Hearing loss, stress, hypertension
• Psychological effects: Irritation, sleep disturbance
• Performance effects: Reduced concentration, productivity
• Communication effects: Speech interference

Table:

Mnemonic: “Air Water Soil Sound” (AWSS)

Question 3(a) [3 marks]

#

What is e-waste? Give effects of e-waste on environment and humans.

#

Answer: E-waste (Electronic waste) consists of discarded electrical and electronic devices containing hazardous materials.

Environmental Effects:

• Soil contamination: Heavy metals leaching
• Water pollution: Toxic chemical runoff
• Air pollution: Burning releases toxic fumes

Human Effects:

• Health hazards: Lead, mercury poisoning
• Respiratory problems: Toxic gas inhalation
• Skin disorders: Direct contact with chemicals

Table:

Mnemonic: “Electronic Equipment Endangers Everyone” (E4)

OR

#

What is plastic waste? Give effects of plastic waste.

#

Answer: Plastic waste consists of discarded plastic materials that persist in environment due to non-biodegradable nature.

Effects:

• Marine pollution: Ocean plastic accumulation
• Wildlife impact: Entanglement, ingestion by animals
• Soil degradation: Reduced fertility and water infiltration
• Human health: Microplastics in food chain

Categories:

• Single-use plastics: Bags, bottles, straws
• Packaging waste: Food containers, wrappings
• Industrial plastic: Manufacturing waste

Mnemonic: “Plastic Persists, Problems Persist” (PPPP)

Question 3(b) [3 marks]

#

Give main sources of solid waste.

#

Answer: Solid waste originates from various human activities and natural processes.

Sources:

• Residential: Household garbage, food waste
• Commercial: Office waste, packaging materials
• Industrial: Manufacturing waste, chemicals
• Agricultural: Crop residues, animal waste
• Municipal: Street sweeping, park maintenance

Table:

Mnemonic: “Residential Commercial Industrial Agricultural Municipal” (RCIAM)

OR

#

Enlist various methods of solid waste disposal and explain any one.

#

Answer: Disposal Methods:

• Landfilling: Controlled waste burial
• Incineration: Waste burning with energy recovery
• Composting: Organic waste decomposition
• Recycling: Material recovery and reuse

Sanitary Landfill:

• Design: Engineered system with liners
• Operation: Daily cover, compaction
• Environmental protection: Leachate and gas control

Mnemonic: “Land Incinerate Compost Recycle” (LICR)

Question 3(c) [4 marks]

#

Explain the working of Liquid Flat Plate Collector with a neat sketch.

#

Answer: Liquid Flat Plate Collector converts solar radiation into thermal energy for heating water.

Working:

• Solar absorption: Black absorber plate captures solar energy
• Heat transfer: Absorbed heat transfers to flowing liquid
• Circulation: Heated liquid rises, cool liquid enters
• Insulation: Minimizes heat losses

Components:

• Transparent cover: Reduces convection losses
• Absorber plate: Maximum solar absorption
• Heat transfer fluid: Water or antifreeze solution

Mnemonic: “Solar Absorption Creates Heat Transfer” (SACHT)

OR

#

Write short note on solar pond

#

Answer: Solar pond is a pool of saltwater that acts as both solar collector and thermal storage system.

Structure:

• Upper zone: Low salt concentration
• Middle zone: Increasing salt gradient
• Lower zone: High salt concentration

Working:

• Density gradient: Prevents convection mixing
• Heat storage: Bottom layer stores thermal energy
• Temperature: Can reach 70-85°C at bottom

Applications:

• Power generation: Steam production
• Industrial heating: Process heat supply
• Desalination: Water purification

Mnemonic: “Salt Stores Solar Thermal” (SSST)

Question 3(d) [4 marks]

#

Explain Savonious wind mill with a neat sketch.

#

Answer: Savonius wind turbine is a vertical axis wind turbine with S-shaped rotor blades.

Working:

• Drag principle: Wind creates differential drag on blades
• Rotation: S-shape causes continuous rotation
• Self-starting: Starts at low wind speeds
• Vertical axis: Independent of wind direction

Advantages:

• Simple design: Low maintenance requirements
• Low noise: Quiet operation
• All wind directions: Omnidirectional capability

Disadvantages:

• Lower efficiency: 20-30% compared to HAWT
• Space requirement: Larger area needed

Mnemonic: “S-Shape Starts Slowly” (SSS)

OR

#

Give the comparison between Horizontal Axis and Vertical Axis wind mills.

#

Answer: Wind turbines are classified based on rotor axis orientation.

Comparison Table:

HAWT Features:

• Upwind design: Rotor faces wind
• Pitch control: Blade angle adjustment
• Yaw system: Wind direction tracking

VAWT Features:

• Omnidirectional: No wind tracking needed
• Ground installation: Easier maintenance
• Lower wind speeds: Better performance

Mnemonic: “Horizontal High, Vertical Versatile” (HHVV)

Question 4(a) [3 marks]

#

Give effects of climate change.

#

Answer: Climate change causes widespread environmental and socio-economic impacts globally.

Environmental Effects:

• Temperature rise: Global average increase
• Sea level rise: Thermal expansion and ice melting
• Weather extremes: Intense storms, droughts, floods
• Ecosystem shifts: Species migration and extinction

Socio-economic Effects:

• Agricultural impact: Crop yield changes
• Water resources: Availability and quality issues
• Human health: Heat stress, disease spread
• Economic losses: Infrastructure damage

Table:

Mnemonic: “Temperature Sea Weather Ecosystem” (TSWE)

OR

#

Write a short note on Green House gases.

#

Answer: Greenhouse gases trap heat in Earth’s atmosphere, causing global warming through greenhouse effect.

Major Greenhouse Gases:

• Carbon dioxide (CO₂): 76% of emissions
• Methane (CH₄): 16% of emissions
• Nitrous oxide (N₂O): 6% of emissions
• Fluorinated gases: 2% of emissions

Sources:

• CO₂: Fossil fuel burning, deforestation
• CH₄: Agriculture, landfills, livestock
• N₂O: Fertilizers, fossil fuel combustion

Global Warming Potential:

• CO₂: Reference (GWP = 1)
• CH₄: 25 times CO₂
• N₂O: 298 times CO₂

Mnemonic: “Carbon Methane Nitrous Fluorine” (CMNF)

Question 4(b) [4 marks]

#

Explain climate change Management.

#

Answer: Climate change management involves strategies to reduce greenhouse gas emissions and adapt to climate impacts.

Mitigation Strategies:

• Renewable energy: Solar, wind, hydroelectric power
• Energy efficiency: Improved building designs, LED lighting
• Carbon sequestration: Forest conservation, tree planting
• Sustainable transport: Electric vehicles, public transport

Adaptation Strategies:

• Infrastructure resilience: Flood defenses, drought-resistant crops
• Water management: Rainwater harvesting, efficient irrigation
• Coastal protection: Sea walls, mangrove restoration
• Emergency preparedness: Early warning systems

Policy Measures:

• Carbon pricing: Tax on emissions
• Renewable energy targets: Clean energy goals
• Building codes: Energy efficiency standards

Mnemonic: “Mitigation Adaptation Policy” (MAP)

OR

#

Give effects of ozone layer depletion.

#

Answer: Ozone layer depletion reduces stratospheric ozone, allowing harmful UV radiation to reach Earth.

Effects on Humans:

• Skin cancer: Increased UV-B radiation exposure
• Eye cataracts: UV damage to eye lens
• Immune suppression: Weakened immune system
• Premature aging: Skin damage acceleration

Effects on Environment:

• Crop damage: Reduced agricultural productivity
• Marine ecosystem: Phytoplankton reduction
• Material degradation: Plastic and rubber damage
• Climate change: Ozone as greenhouse gas

Table:

Mnemonic: “Skin Eyes Immunity Climate” (SEIC)

Question 4(c) [7 marks]

#

Explain biogas plant with sketch.

#

Answer: Biogas plant produces methane-rich gas through anaerobic digestion of organic waste.

Components:

• Digester tank: Anaerobic fermentation chamber
• Gas dome: Biogas collection and storage
• Inlet pipe: Waste material feeding
• Outlet pipe: Digested slurry removal

Process:

• Hydrolysis: Complex organics break down
• Acidogenesis: Acid-forming bacteria action
• Methanogenesis: Methane-producing bacteria
• Gas production: 50-70% methane, 30-40% CO₂

Operating Conditions:

• Temperature: 30-40°C optimal
• pH: 6.8-7.2 range
• Retention time: 15-30 days
• C:N ratio: 20-30:1 optimal

Applications:

• Cooking fuel: Household energy needs
• Lighting: Gas lamp illumination
• Electricity: Generator power
• Fertilizer: Nutrient-rich slurry

Advantages:

• Renewable energy: Sustainable fuel source
• Waste management: Organic waste utilization
• Environmental benefits: Reduced methane emissions
• Economic benefits: Cost savings on fuel

Mnemonic: “Biogas Benefits: Renewable Waste Environment Economy” (BRWEE)

Question 5(a) [4 marks]

#

Write short note on global warming.

#

Answer: Global warming refers to long-term increase in Earth’s average surface temperature due to human activities.

Causes:

• Greenhouse gases: CO₂, CH₄, N₂O emissions
• Deforestation: Reduced carbon absorption
• Industrial activities: Fossil fuel combustion
• Transportation: Vehicle emissions

Effects:

• Temperature rise: 1.1°C since pre-industrial times
• Ice melting: Arctic sea ice, glaciers shrinking
• Sea level rise: Coastal flooding threat
• Weather changes: Extreme events frequency

Evidence:

• Temperature records: Warmest years in recent decades
• Ice core data: Historical CO₂ levels
• Satellite measurements: Global temperature monitoring

Solutions:

• Renewable energy: Clean power sources
• Energy efficiency: Reduced consumption
• Carbon capture: Technology development
• International cooperation: Paris Agreement

Mnemonic: “Greenhouse Gases Generate Global Change” (GGGC)

Question 5(b) [4 marks]

#

Explain 5R concept.

#

Answer: 5R concept is waste management hierarchy for sustainable resource utilization.

graph TD
    A[5R Hierarchy] --> B[Refuse]
    A --> C[Reduce]
    A --> D[Reuse]
    A --> E[Repurpose]
    A --> F[Recycle]

The 5 R’s:

1. Refuse:

• Avoid unnecessary items: Say no to single-use products
• Examples: Plastic bags, straws, excessive packaging

2. Reduce:

• Minimize consumption: Use less resources
• Examples: Energy conservation, water saving

3. Reuse:

• Multiple use: Extend product life
• Examples: Glass jars as containers, paper both sides

4. Repurpose:

• Creative reuse: New function for old items
• Examples: Tire planters, bottle bird feeders

5. Recycle:

• Material recovery: Process into new products
• Examples: Paper, plastic, metal recycling

Benefits:

• Waste reduction: Less landfill burden
• Resource conservation: Natural resource preservation
• Cost savings: Economic benefits
• Environmental protection: Pollution reduction

Mnemonic: “Refuse Reduce Reuse Repurpose Recycle” (R5)

Question 5(c) [3 marks]

#

Explain the benefits of Green building.

#

Answer: Green building incorporates sustainable design and construction practices for environmental and human benefits.

Environmental Benefits:

• Energy efficiency: Reduced power consumption
• Water conservation: Efficient water systems
• Waste reduction: Construction and operational waste minimization

Economic Benefits:

• Operating cost savings: Lower utility bills
• Increased property value: Market premium
• Tax incentives: Government rebates

Health Benefits:

• Indoor air quality: Better ventilation systems
• Natural lighting: Improved occupant comfort
• Toxic material reduction: Healthier environment

Table:

Mnemonic: “Green Buildings Give Environmental Economic Health” (GBEEH)

Question 5(d) [3 marks]

#

Enlist various Acts related to environment in India and explain any one.

#

Answer: Environmental Acts in India:

• Water (Prevention and Control of Pollution) Act, 1974
• Air (Prevention and Control of Pollution) Act, 1981
• Environment Protection Act, 1986
• Wildlife Protection Act, 1972
• Forest (Conservation) Act, 1980
• Biodiversity Act, 2002

Environment Protection Act, 1986: Objectives:

• Comprehensive framework: Overall environmental protection
• Pollution prevention: Air, water, soil contamination control
• Standard setting: Environmental quality standards
• Enforcement: Penalties for violations

Powers:

• Central government authority: Environmental regulations
• Inspection rights: Industrial facilities monitoring
• Closure orders: Non-compliant industries
• Emergency measures: Environmental hazards response

Significance:

• Umbrella legislation: Covers all environmental aspects
• Post-Bhopal disaster: Response to industrial accidents

Mnemonic: “Water Air Environment Wildlife Forest Biodiversity” (WAEWFB)