Water pollution, along with air pollution, global warming, and ozone, are key topics for the AP exam.
Nearly one-third of AP exam multiple-choice questions involve pollution.
Important to understand terms and concepts related to pollution.
Introduction to Water Pollution
Initial story about Chesapeake Bay, the largest estuary in the US.
Environmental issues mainly from human activities like animal feeding lots and pharmaceutical dumping.
Definition of Water Pollution
Contamination of water bodies by substances from human activities affecting organisms negatively.
Point Sources: Identifiable singular polluters, such as a factory.
Non-point Sources: Diffuse sources, like farming regions, difficult to pinpoint.
Types of Water Pollutants
Human and Animal Waste: Human sewage, gray water, and animal waste.
Inorganic Substances: Includes heavy metals like lead and mercury.
Organic Compounds: Chemicals used in manufacturing.
Non-Chemical Pollutants: Includes sediment and thermal pollution.
Concerns about Wastewater
Oxygen-demanding wastes deplete oxygen needed by aquatic life.
Nutrient pollution (nitrogen and phosphorus) from wastewater leads to eutrophication.
Water Quality Indicators
Dissolved Oxygen (DO): Good quality water has DO between 8-9 ppm.
Biochemical Oxygen Demand (BOD): High BOD indicates more polluted water.
Treatment of Wastewater
Septic Systems: Used in rural areas, relies on gravity, processes waste in a septic tank.
Sewage Treatment Plants: Used in urban areas.
Primary Treatment: Removes solid waste.
Secondary Treatment: Bacteria break down organic matter, water is aerated.
Tertiary Treatment: Further removes nutrients like nitrogen and phosphorus.
Industrial and Other Pollutants
Heavy Metals: Lead, arsenic, mercury.
Pesticides and Herbicides: Chemicals like DDT and atrazine.
Acid Deposition: From burning fossil fuels.
Industrial Compounds: PCBs and PBDEs lead to environmental and health issues.
Oil Pollution
Sources include natural seeps and human activities.
Notable spills: BP Deepwater Horizon, Exxon Valdez.
Cleanup methods: Booms, vacuums, chemicals, and bacteria.
Other Pollutants
Solid Waste: Trash and debris.
Sediment Pollution: From construction and deforestation, affects water clarity.
Thermal Pollution: From industrial discharges.
Noise Pollution: Affects marine life communication.
Legislation
Clean Water Act (1972): Focuses on chemical properties of surface waters.
Safe Drinking Water Act: Sets standards for drinking water safety.
Challenges in Developing Countries
Less restrictive environmental laws and fewer resources.
Need for clean water and proper sanitation facilities.
Conclusion
Understanding and managing water pollution is crucial for environmental health and is a significant part of ecological studies and assessments like the AP exam.