Flashcards in Apes Ch.21 Deck (18):
Biological oxygen demand
the amount of oxygen needed by microorganisms to decompose biological wastes into carbon dioxide, water, and minerals
Over nourishment of aquatic ecosystems with plant nutrients (mostly nitrates and phosphates) because of human activities such as agriculture, urbanization, and discharges from industrial plants and sewage treatment plants.
process by which a body of water becomes too rich in dissolved nutrients, leading to plant growth that depletes oxygen
Primary sewage treatment
Mechanical sewage treatment in which large solids are filtered out by screens and suspended solids settle out as sludge in a sedimentation tank
step in most waste treatment systems in which aerobic bacteria decompose up to 90% of degradable, oxygen-demanding organic wastes in wastewater. This usually involves bringing sewage and bacteria together in trickling filters or in the activated sludge process. Compare advanced sewage treatment, primary sewage treatment.
Gooey mixture of toxic chemicals, infectious agents, and settled solids removed from wastewater at a sewage treatment plant.
Us safe drinking water
a federal program to monitor and increase the safety of the drinking water supply
Clean water act
regulatory and non regulatory tools to protect all surface waters in the US in 1972. reduced direct pollutant discharges, financed municipal wastewater treatment facilities, achieved broader goal of restoring/maintaining chemical, physical, and biological integrity of the nation's waters
Oxygen sag curve
a flowing stream, the breakdown of degredable wastes by bacteria depletes dissolved oxygen, creating an oxygen sag curve. This curve reduces of eliminates populations of organisms with high oxygen requirements, until the stream is cleansed of wastes
- anything that flows out
condition of low oxygen
series of specialized chemical and physical processes to remove specific pollutants left in the water after primary and secondary treatment
Wastewater treatment plant
system in which most waterborne wastes form homes, businesses, factories, and storm runoff flow through a network of sewar pipes to wastewater/ sewage treatment plants
un-enriched, clear water that supports small populations of aquatic organisms. Contains large amounts of dissolved oxygen and low nutrient levels. Fish include Trout, pike, sturgeon, and small mouth bass.
Blue baby syndrome
caused by nitrate contamination in groundwater resulting in decreased oxygen carrying capacity of haemoglobin in babies leading to death.
big container or steel tank that is buried in the yard and may hold 1,000 gallons of water. Wastewater flows into the tank at one end and leaves the tank at the other.
Discharge trading policy
pollution source is allowed to pollute at levels higher than allowed in its permit if it buys credits from permit holders with pollution levels below what they are allowed.