APES UNIT 8

🚰 Sources of Water Pollution

🔹 Point Source Pollution: Pollutants released from specific, identifiable sources (e.g., discharge pipes, factories).
🔸 Non-Point Source Pollution: Pollutants originating from widespread areas (e.g., agricultural runoff, urban stormwater).
🔥 Thermal Pollution: Water temperature changes due to industrial processes, affecting ecosystems.

Eutrophication

Definition: Human activities increase nutrient levels in surface waters, leading to ecosystem imbalances.

Ecological Effects of Cultural Eutrophication

🔸 Changes in species composition and dominance
🔹 Toxic gas release from decomposed algae
🔸 Decreased biodiversity and fish kills due to hypoxia (low oxygen)
🔹 Increased algal blooms and turbidity (cloudy water)
🔸 Growth of toxic phytoplankton species

Human Activities Contributing to Cultural Eutrophication

🔹 Wastewater discharge with excess nutrients
🔸 Fertilizers and pesticide runoff from agriculture
🔹 Sewer overflows during heavy rainfall
🔸 Household products containing phosphates

Controlling Cultural Eutrophication

🔹 Reduce runoff from feedlots and manage fertilizer application
🔸 Construct wastewater lagoons and retention ponds
🔹 Plant buffer vegetation along streambeds
🔸 Upgrade water treatment plants to remove nitrates and phosphates
🔹 Use permeable pavement to reduce urban runoff

Biodegradable Wastes

💧 Nitrates: Water-soluble, cause algal blooms and low dissolved oxygen
🌱 Phosphates: Attach to soil, contribute to nutrient pollution
🦠 Microorganisms: Cause waterborne diseases

Mining & Water Pollution

🔹 Cyanide used to extract gold contaminates water
🔸 Heavy metals and sulfur compounds leach into freshwater
🔹 Waste dumped into rivers pollutes aquatic ecosystems
🔸 Rainwater on mine tailings spreads toxins

Effects of Oil Spills

🐦 Seabirds ingest oil, damaging kidneys and livers
🔹 Oil blocks sunlight, disrupting marine food webs
🔸 Seabirds lose buoyancy, struggle to regulate temperature
🛢 Clean-up methods: Dispersants, skimming, vacuuming, controlled burning, bioremediation

Great Pacific Garbage Patch

🌊 A massive swirling gyre of marine debris in the Pacific Ocean
🔹 Formed by ocean currents trapping plastic waste
🔸 Plastic photodegrades, releasing toxins into the water
🐟 Small plastic particles enter the marine food chain, affecting wildlife

♻ Solution: Reduce plastic waste and improve waste management policies!

🛢 Persistent Organic Pollutants (POPs)

🔹 Definition: Carbon-based compounds resistant to degradation, persisting in the environment and accumulating in living organisms.
🔸 Effects: Long-range transport, bioaccumulation, biomagnification, and harmful impacts on ecosystems and human health.

Chemical Characteristics of POPs

🔹 Travel long distances before deposition
🔸 Evaporate in hot regions, condense in cold areas
🔹 High molecular mass and fat solubility (accumulate in tissues)
🔸 Low water solubility

🏙 Urban Runoff Impacts

🔹 Creates microclimates due to asphalt heat retention
🔸 Fragments habitats and reduces biodiversity
🔹 Depletes groundwater by preventing infiltration

💧 Water Quality & Testing

🔹 Water Quality: Measures chemical, physical, and biological characteristics relative to ecological and human needs.
🔸 Water Testing: Various procedures to analyze water conditions.

Water Quality Tests

🧪 Alkalinity: Buffers pH changes, aiding fish survival.
⚠ Ammonia: Indicates pollution, rapidly oxidizes to nitrates.
🌿 Biological Oxygen Demand (BOD): Measures biodegradable waste levels.
💨 Carbon Dioxide: High levels lower pH, harming aquatic life.
🐟 Dissolved Oxygen (DO): Low levels indicate pollution and ecosystem stress.
🦠 Coliforms: Bacteria from fecal contamination, signaling sewage pollution.
⚡ Heavy Metals (Pb, Hg, Cd, Se): Increase toxicity in acidic conditions, causing bioaccumulation and health issues.
🚰 Nitrate/Nitrite: Affect human and aquatic health through oxygen depletion.
⚖ pH: Influences biodiversity, heavy metal solubility, and water acidity.
🦠 Phosphates: Needed in low amounts, but excess leads to algal blooms.
🌊 Salinity: Essential for osmotic balance, but fluctuations affect aquatic life.
💦 Total Dissolved Solids (TDS): Impact clarity, photosynthesis, and drinking water quality.
🌡 Temperature: Warmer water holds less oxygen and increases toxicity.
🧪 Total Hardness: Measures calcium and magnesium, affecting metal solubility.
🌫 Turbidity: Indicates suspended solids, reducing water clarity.

🚰 Drinking Water Treatment Methods

🧽 Absorption: One substance fully enters another.
🛡 Adsorption: Substances cling to surfaces.
🦠 Disinfection: Eliminates infectious organisms.
🌀 Filtration: Removes sediments and improves clarity.
🌊 Flocculation Sedimentation: Clumps small particles into sediment.
⚛ Ion Exchange: Removes contaminants like arsenic and nitrates.

💧 Clean Water = Healthier Ecosystems! 🌍

🧬 Endocrine Disruptors

🔹 Gland: An organ that secretes chemicals for bodily functions.
🔸 Endocrine System: A network of glands producing hormones that regulate body functions.
🔹 Endocrine Disruptors: Chemicals that interfere with hormonal systems, causing developmental, reproductive, and health issues.

⚠ Common Endocrine Disruptors

🧴 Bisphenol A (BPA) – Found in plastics and epoxy.
🔥 Dioxins – By-products of herbicide production, paper bleaching, and waste burning.
🛍 Phthalates – Added to plastics to increase flexibility.
⚡ Polychlorinated Biphenyls (PCBs) – Used in electrical equipment, heat transfer fluids, and lubricants.

💡 Exposure to these chemicals can lead to birth defects, learning disorders, tumors, and infertility.

🌊 Wetlands

Land covered by water—freshwater, saltwater, or brackish.
🔹 Includes marshes, ponds, river deltas, and flood-prone areas.
🔸 Serve as breeding grounds and nurseries for many species.
🔹 Essential for rice cultivation, a staple for half the world’s population.

🌱 Mangroves

Shrubs or small trees growing in brackish water (mix of seawater and freshwater).
🔹 Possess specialized roots and salt filtration to survive in harsh conditions.
🔸 Protect coastlines from erosion and provide habitat for marine life.

⚠ Human Impacts

🏗 Diking & Dredging – Alters water flow and disrupts ecosystems.
🏙 Urban Development – Filling wetlands for expansion affects water quality.
🌪 Increased Hurricanes – More frequent storm surges damage these ecosystems.

🔬 Bioaccumulation

The buildup of pollutants in an organism over time.
📈 Factors affecting bioaccumulation:
🔹 Mode of uptake
🔸 Fat solubility of the pollutant
🔹 Rate of elimination
🔸 Metabolic transformation
🔹 Lipid (fat) content of the organism

🌍 Biomagnification

The increasing concentration of a pollutant in organisms at higher trophic levels in a food chain.
📌 For biomagnification to occur, the pollutant must:
✔ Be long-lived
✔ Be mobile
✔ Be fat-soluble
✔ Be biologically active

⚠ Example: Mercury in fish or DDT in birds of prey.

🗑 Municipal Solid Waste (MSW)

➡ Everyday trash or garbage

⚠ Hazardous Waste

🖌 Paints, chemicals, pesticides—takes hundreds of years to decompose

🍏 Organic Waste

🌿 Kitchen waste, leaves, fruits—decomposes in 2 weeks
🌳 Wood takes 10-15 years

☢ Radioactive Waste

🔥 Spent fuel rods, smoke detectors—decomposes in thousands of years

🔄 Recyclable Waste

📄 Paper (10-30 days)
🥤 Some plastics (up to 1 million years)
🔶 Metals (100-500 years)
🔍 Glass never decomposes

🩺 Soiled Waste

🏥 Hospital waste—cotton & cloth decompose in 2-5 months

💨 Anaerobic Digestion

🔬 Microorganisms break down waste without oxygen
✅ Produces renewable energy
✅ Reduces organic waste & methane emissions
✅ Nutrient-rich digestate can be used as fertilizer

♻ Waste Disposal & Energy Recovery

🔥 Incineration → Burns waste, converts to ash & heat
🌎 Global Waste Trade → Developed countries export waste to developing ones
🌊 Ocean Dumping → Disposal of waste at sea
🗑 Sanitary Landfills → Waste is buried to isolate it from the environment

🌍 Reducing Waste

✅ Substitute hazardous products with eco-friendly alternatives

☢ Hazardous Waste Management

🚛 Landfill Capping → Covers hazardous waste with three protective layers
⚠ Hazardous Waste Landfills → Specially designed to minimize leaks
🏭 Permanent Storage → Isolates hazardous waste long-term

🛢 Methods of Storage

🕳 Geologic Repositories → Salt domes, underground caves
💦 Injection Wells → Store liquid waste deep underground
🏗 Waste Piles → Temporary storage for non-liquid hazardous waste

🏭 Brownfields

🏢 Previously used industrial land, possibly contaminated
🌆 Found in large urban areas

♻ Reducing Hazardous Waste

✅ Produce less waste
✅ Convert to less toxic materials
✅ Store in perpetual storage