ch5: water pollution Flashcards
Define water pollution:
- Any physical or chemical change in water that adversely affects the health of humans and other organisms
- Varies in magnitude by location
Types of water pollution:
- Sewage
- Disease-causing agents
- Sediment pollution
- Inorganic plant and algal nutrients
- Organic compounds
- Inorganic chemicals
- Radioactive substances
- Thermal pollution
Sources of water pollution:
- Point sources
- Non-point sources
Global water pollution issue:
- Lack of disease free water
Define sewage:
- The release of wastewater from drains or sewers
- Include
- Human wastes
- Soaps
- Detergents
Sewage causes environmental problems which are:
- Enrichment
- Fertilization of a body of water by high levels of plant and algal nutrients
- Nitrogen and phosphorus
- Fertilization of a body of water by high levels of plant and algal nutrients
- Increase in BOD
- Amount of oxygen needed by microorganisms to decompose biological wastes
- As BOD increase DO decreases
- Amount of oxygen needed by microorganisms to decompose biological wastes
Sewage eutrophication:
- Oligotrophic
- Unenriched, clear water that supports small populations of aquatic organisms
- Causes:
- Low nutrient levels
- Good light penetration
- High dissolved oxygen
- Deep waters
- Low algal growth
- Small mouth bass, lake trout, pike, sturgeon, white fish
- Eutrophic
- Slow-flowing stream, lake or estuary enriched by inorganic plant and algal nutrients such as phosphorus
- Often due to fertilizer or sewage runoff
- Causes:
- High nutrient levels
- Poor light penetration
- Low dissolved oxygen
- Shallow waters
- High algal growth
- Carp, bullhead, catfish
Define disease causing agents:
- Infectious organisms that cause diseases
- Originate in the wastes of infected individuals
- Common bacterial or viral diseases:
- Typhoid
- Cholera
- Bacterial dysentery
- Polio
- Infectious hepatitis
How is the presence of disease causing agents tested in the water?
- By fecal coliform tests
- Testing for presence of E. coli in the water
- The test indicate the presence of pathogenic organisms
- Testing for presence of E. coli in the water
Sediment pollution:
- Excessive amounts of suspended soil particles
- Originates from:
- erosion of agricultural lands,
- forest soils exposed by logging,
- degraded stream banks,
- overgrazed rangelands,
- strip mines, and
- construction
- problems:
- limits light penetration
- covers aquatic animals and plants
- brings insoluble toxins into water ways
Compare streams with low vs high level of sediment
Stream with low level of sediment
Stream with high level of sediment
Many potential shelters for small aquatic organisms
Potential shelters buried under sediment
Light penetration supports photosynthesis of algae and aquatic plants
Sediment prevent light penetration; photosynthetic organisms cannot survive along bottom
Bacteria, protozoa, insect larvae attach to rocks
Aquatic organisms attached to rocks removed by sediment washing along bottom
Inorganic plant and algal nutrients:
- Chemicals such as nitrogen and phosphorus that stimulate the growth of plants and algae
- Harmful in large concentrations
- Sources:
- Human and animal wastes,
- plant residues,
- atmospheric deposition, and
- fertilizer runoff
- Causes:
- Enrichment,
- bad odors, and
- a high BOD
Define dead zone:
- hypoxic (low-oxygen) areas in the world’s oceans and large lakes
- caused by:
- Excessive nutrient pollution from human activities
- Effect:
- Coupled with other factors it deplete the oxygen required to support most marine life in bottom and near-bottom water.
Organic compounds:
- Chemicals that contain carbon atoms
- Natural examples:
- sugars,
- amino acids, and
- oils
- Human-made examples:
- pesticides,
- solvents,
- industrial chemicals, and
- plastics
inorganic chemicals:
- Contaminants that contain elements other than carbon
- Do not degrade easily
- Examples:
- Acids
- Salts
- Heavy metals
- Lead
- Found in
- old paint
- industrial pollutants
- lead gasoline
- Found in
- mercury
- mercury bio accumulates in the muscles of top predators of the open ocean
