9.6 Environment and Pollution Control

9.6 Environment and Pollution Control

1. Air, Water, Noise and Solid Waste Pollution

1. Air Pollution:

   • Primary Pollutants: Emitted directly from sources.

     • Particulate Matter (PM₁₀, PM₂.₅): Dust, soot, smoke.

     • Sulfur Oxides (SOₓ): Mainly from coal/oil combustion.

     • Nitrogen Oxides (NOₓ): High-temperature combustion.

     • Carbon Monoxide (CO): Incomplete combustion.

     • Volatile Organic Compounds (VOCs): Evaporation of fuels/solvents.

   • Secondary Pollutants: Formed by chemical reactions in atmosphere.

     • Ozone (O₃): Photochemical smog component.

     • PAN (Peroxyacyl nitrates): Eye irritants in smog.

     • Sulfuric/Nitric Acid: Acid rain precursors.

   • Effects: Respiratory diseases, acid rain, ozone depletion, climate change.

   • Control Methods:

     • Source reduction: Cleaner fuels, process modification.

     • End-of-pipe: Scrubbers, filters, electrostatic precipitators, catalytic converters.

2. Water Pollution:

   • Pollutant Types:

     • Physical: Temperature, suspended solids, turbidity.

     • Chemical: Heavy metals, pesticides, nutrients (N, P), organic compounds.

     • Biological: Pathogens, algae blooms.

   • Sources:

     • Point sources: Industrial outfalls, sewage treatment plants.

     • Non-point sources: Agricultural runoff, urban stormwater.

   • Effects: Eutrophication, toxicity to aquatic life, human health risks.

   • Control Methods:

     • Wastewater treatment: Primary (physical), secondary (biological), tertiary (chemical).

     • Advanced treatment: Membrane filtration, activated carbon, disinfection.

     • Industrial pretreatment before discharge to municipal systems.

3. Noise Pollution:

   • Measurement: Sound pressure level in decibels (dB), frequency weighting (dBA).

   • Sources: Industrial machinery, transportation, construction, household appliances.

   • Effects: Hearing loss, stress, sleep disturbance, reduced productivity.

   • Control Methods:

     • Source control: Quieter equipment, vibration isolation.

     • Path control: Barriers, enclosures, distance.

     • Receiver protection: Earplugs, earmuffs.

   • Standards: Occupational (8-hr exposure limits), residential area limits.

4. Solid Waste Pollution:

   • Classification:

     • Municipal Solid Waste (MSW): Household/commercial waste.

     • Industrial Waste: Manufacturing byproducts.

     • Hazardous Waste: Toxic, reactive, flammable, corrosive.

     • Biomedical Waste: Infectious materials.

   • Management Hierarchy:

     1. Source reduction (most preferred)

     2. Reuse

     3. Recycling

     4. Energy recovery (waste-to-energy)

     5. Disposal (least preferred)

   • Disposal Methods:

     • Landfills: Engineered sites with liners, leachate collection.

     • Incineration: Volume reduction, energy recovery, but air emissions.

     • Composting: Organic waste to soil conditioner.

2. Global and National Environmental Issues

1. Global Issues:

   • Climate Change:

     • Enhanced greenhouse effect from anthropogenic emissions.

     • Main GHGs: CO₂ (76%), CH₄ (16%), N₂O (6%), F-gases (2%).

     • Impacts: Sea-level rise, extreme weather, ecosystem disruption.

     • Agreements: UNFCCC, Kyoto Protocol, Paris Agreement (limit warming to 1.5-2°C).

   • Ozone Depletion:

     • CFCs, halons destroy stratospheric ozone layer.

     • Ozone hole over Antarctica.

     • Montreal Protocol (1987): Phasing out ODS, successful example.

   • Biodiversity Loss:

     • Habitat destruction, pollution, climate change, invasive species.

     • Current extinction rate 100-1000 times natural background.

     • Convention on Biological Diversity.

   • Ocean Acidification:

     • CO₂ absorption → carbonic acid → lower pH.

     • Affects marine organisms with calcium carbonate shells/skeletons.

2. National Issues (India-specific):

   • Air Quality:

     • Cities often exceed WHO guidelines (Delhi, Kolkata, Mumbai).

     • Major sources: Vehicular emissions, industrial emissions, construction dust, biomass burning.

     • National Clean Air Programme (NCAP): Target 20-30% PM reduction by 2024.

   • Water Stress:

     • 17% of world's population with 4% of freshwater resources.

     • Groundwater depletion in Punjab, Haryana, Rajasthan.

     • Pollution of major rivers (Ganga, Yamuna).

     • National River Conservation Plan, Jal Jeevan Mission.

   • Waste Management:

     • 62 million tonnes MSW annually (expected to double by 2030).

     • Low recycling rates, landfill issues.

     • Swachh Bharat Mission, Plastic Waste Management Rules.

   • Deforestation and Land Degradation:

     • 21.67% forest cover (target: 33%).

     • Competing land uses: Agriculture, urbanization, infrastructure.

     • National Afforestation Programme.

3. Pollution Control Framework:

   • Regulatory Bodies:

     • Central Pollution Control Board (CPCB) at national level.

     • State Pollution Control Boards (SPCBs) at state level.

   • Legislation:

     • Air (Prevention and Control of Pollution) Act, 1981.

     • Water (Prevention and Control of Pollution) Act, 1974.

     • Environment Protection Act, 1986.

     • National Green Tribunal Act, 2010.

   • Standards:

     • National Ambient Air Quality Standards (NAAQS).

     • Effluent discharge standards for industries.

     • Emission standards for vehicles (Bharat Stages).

4. Sustainable Development Goals (SDGs):

   • 17 global goals adopted by UN (2015).

   • Relevant goals: Clean water & sanitation (6), Affordable & clean energy (7), Industry & infrastructure (9), Sustainable cities (11), Climate action (13).

   • India's progress tracked through National Indicator Framework.

5. Economic Instruments:

   • Pollution taxes/charges.

   • Emissions trading schemes.

   • Subsidies for clean technologies.

   • Extended Producer Responsibility (EPR).