Water Pollution Study Notes

Water Pollution and Its Dangers

Definition of Water Pollution

  • Water Pollution occurs when any artificial products are present in water.

    • These artificial products are referred to as pollutants or contaminants.

    • Types of Pollutants include:

    • Organic and Inorganic Chemicals

    • Pathogens (infectious microorganisms)

    • Macroscopic Objects such as:

      • Trash

      • Shipwrecks

      • Plastics

      • Any other debris

Global Impact of Water Pollution

  • Water pollution is a significant issue affecting freshwater sources worldwide.

  • Developing Countries:

    • Face challenges in controlling acute water pollution due to limited resources.

  • Developed Countries:

    • Also experience struggles with pollution.

    • In the United States:

    • 44% of streams, 64% of lakes, and 30% of bays have been classified as polluted.

  • Oceans vs. Freshwater:

    • Generally, the vast oceans are less polluted than freshwater sources.

    • There may still be surface pollution; however, due to their depth and size, most of the ocean remains relatively unpolluted.

Rising Acidity in the Ocean

  • Concern about how industrialization has impacted ocean pH levels:

    • Over the past 200 years, the increase in industrialization has led to a greater release of the greenhouse gas CO2 into the atmosphere.

    • The ocean absorbs approximately 30% of this CO2, which subsequently alters its chemistry.

    • Chemical Reactions:

    • $CO2 + H2O
      ightleftharpoons H2CO3
      ightleftharpoons H^+ + HCO_3^-$

    • Result:

    • The formation of carbonic acid releases H+ ions, lowering the pH and increasing the acidity of the ocean.

Effects of Ocean Acidification

  • Impact on Marine Life:

    • Ocean acidification poses a threat to various types of marine life.

    • Shelled Mollusks:

    • Struggle to deposit calcium carbonate into their shells as carbonate ions become less available.

    • Additionally, lower pH levels result in thinner shells, increasing vulnerability to predation and environmental stressors.

Types of Water Pollution Sources

Point Sources of Pollution

  • Point sources are defined as locations that release contaminants into water from a single source.

    • Examples include:

    • Factories

    • Sewage treatment plants

    • Storm drains

  • Contaminant Collection: Water running over streets collects pollutants such as chemicals from automobile exhaust and oils. This water is often directed towards larger water bodies via storm drains.

Non-Point Sources of Pollution

  • Non-point sources cannot be attributed to a single origin and involve contamination over a broad area.

    • Common examples include:

    • Leaching of Nitrogen-Containing Compounds from fertilized agricultural fields.

    • Accumulation of Phosphates:

      • Found in fertilizers and cleaning products (dishwasher and laundry detergents).

      • Result in significant phosphorous pollution in streams and lakes from runoff in residential areas where these products are used.