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1. Water Pollution
Definition: Water pollution refers to the contamination of water bodies (like lakes, rivers, oceans, and groundwater) due to harmful substances.
Pollutants: Chemicals, waste materials, and microorganisms that degrade water quality.
Causes: Industrial waste, agricultural runoff, sewage disposal, and plastic waste.
Effects: Makes water unsafe for drinking, bathing, fishing, and other activities.
Common Pollutants: Heavy metals, pesticides, fertilizers, and pathogens.
Global Issue: Water pollution significantly affects the availability of clean drinking water worldwide.
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2. Impurities in Water
Physical Impurities: Suspended solids like dirt, sand, and organic materials make water appear cloudy.
Chemical Impurities: Harmful chemicals such as nitrates, phosphates, heavy metals (e.g., lead, mercury), and industrial toxins.
Biological Impurities: Microorganisms like bacteria, viruses, and parasites that can cause waterborne diseases.
Organic Impurities: Waste products like dead plants, animal matter, and fecal waste.
Dissolved Gases: Harmful gases such as hydrogen sulfide or high levels of carbon dioxide.
Radioactive Contaminants: Pollutants from industrial discharges or accidents can make water radioactive.
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3. Causes of Water Pollution
Industrial Waste: Factories discharge harmful chemicals, heavy metals, and toxins directly into water bodies.
Sewage and Wastewater: Untreated sewage from households is often dumped into rivers or lakes.
Agricultural Runoff: Fertilizers, pesticides, and herbicides used in farming can enter water bodies.
Plastic Waste: Plastics, especially microplastics, pollute water bodies and harm aquatic life.
Oil Spills: Accidental or illegal oil discharges into oceans and seas.
Mining: Mining releases harmful substances like arsenic, mercury, and lead into nearby water bodies.
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4. Effects of Water Pollution on Human Health
Waterborne Diseases: Causes diseases like cholera, diarrhea, typhoid, and dysentery.
Heavy Metal Poisoning: Ingesting contaminated water can lead to poisoning by heavy metals like mercury and lead.
Long-Term Health Effects: Prolonged exposure to polluted water can cause cancer, liver damage, and neurological disorders.
Food Safety: Polluted water affects food safety as contaminated water is used for irrigation.
Skin Infections: Direct contact with polluted water can cause skin infections, rashes, and irritation.
Public Health Impact: Contaminated drinking water increases infant mortality and impacts overall public health.
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5. Concept of Dissolved Oxygen (DO), Biological Oxygen Demand (BOD), and Chemical Oxygen Demand (COD)
Dissolved Oxygen (DO): Amount of oxygen dissolved in water, essential for aquatic life. Lower DO levels indicate pollution.
Biological Oxygen Demand (BOD): Measures oxygen needed by microorganisms to decompose organic matter. High BOD suggests high pollution.
Chemical Oxygen Demand (COD): Measures total oxygen needed to oxidize all pollutants, including inorganic and organic.
Importance of DO: Healthy water bodies have high DO levels; polluted water has low DO, affecting aquatic life.
BOD and DO Relationship: High BOD decreases DO, causing suffocation of aquatic organisms.
COD vs. BOD: COD is faster and measures both biodegradable and non-biodegradable pollutants, while BOD measures only biodegradable.
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6. Prevention of Water Pollution
Wastewater Treatment: Industries and municipalities must treat wastewater before releasing it into water bodies.
Ban on Single-Use Plastics: Reducing plastic waste by banning single-use plastics prevents plastic pollution.
Proper Sewage Disposal: Improved sewage systems prevent contamination of water sources.
Eco-friendly Products: Encourage biodegradable products and reduce harmful chemicals like pesticides.
Public Awareness: Educate communities on water conservation, pollution control, and waste disposal techniques.
Strict Regulations: Enforce stricter laws to prevent industries from discharging pollutants into water bodies.
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7. Water (Prevention and Control of Pollution) Act, 1974
Objective: The Act aims to prevent and control water pollution and maintain or restore water quality.
Central and State Boards: Establishes Central and State Pollution Control Boards to regulate and monitor water pollution.
Powers of the Boards: The boards set water quality standards, inspect facilities, and penalize polluting industries.
Effluent Standards: Industries must meet effluent standards for wastewater discharge to prevent pollution.
Penalties: The Act imposes fines and imprisonment for industries that fail to comply with pollution control standards.
Public Participation: The Act allows the public to participate in monitoring and reporting water pollution violations.