Final Study Terms Flashcards
how does water pollution happen?
- water pollution occurs when discharges of energy or materials degrade water
How is water pollution measured
Water pollution is measured by the concentration of pollutants in the water body and their effects on other water uses
What are some water pollutants of concern?
- Oxygen-demanding wastes
- nutrients
- thermal pollution
- toxic material
- acidification
- pathogens
What is one of of the most important measures of the quality of water?
DISSOLVED OXYGEN (D.O.) present
What is eutrophication?
A process whereby water bodies receive excess nutrients that stimulate excessive plant growth
This enhanced plant growth, often called an algal bloom, reduces dissolved oxygen in t he water when dead plant material decomposes and can cause other organisms to die
What are some causes of thermal pollution?
- Power plants creating electricity from fossil fuel and water used as cooling agent
- Deforestation of shoreline
- soil erosion
What are some toxic materials that can affect the health of aquatic organisms?
heavy metals (heavy metals only bad when they show up in large amounts due to industrialization)
pesticides (herbicides, insecticides, fungicides, nematicides, rodenticides)
volatile organic compounds (vinyl chloride, tetrachloroethylene PCE)
What are some effects of acidification?
Acid deposition (acid rain and acid particles)
Minerals (mercury, aluminum, lead become more soluble and therefore more harmful in low pH environments)
What are pathogens and how do they affect water quality?
Pathogens are disease-causing bacteria, viruses and protozoa, usually from human sewage
- Bacteria (cholera, dysentery, typhoid)
- Viruses (hepatitis)
- Protozoa (dysentery, giardiasis)
- Helminth (parasitic worms)
what are the steps of wastewater treatment?
***depends of effluent discharge requirements (ocean, inland stream, environmentally sensitive lakes, streams, estuaries, groundwater)
- Preliminary treatment
- Primary treatment
- Secondary treatment
- Advanced (tertiary) wastewater treatment
Classification of preliminary treatment (for wastewater)
pumping, screening, grit removal
Classification of primary treatment (for wastewater)
sedimentation (a portion of suspended solids and organic matter removed approx. 30% BOD and 60% TSS
Classification of secondary treatment (for wastewater)
Further treatment of effluent from primary treatment for residual organic matter and suspended solids removal approx. 90% BOD and TSS
Typically biological reactors (i.e. activated sludge process, trickling filter)
Classification of advanced (tertiary) wastewater treatment (for wastewater)
Effluent from secondary treatment may be further treated to reduce specific chemical constituents in wastewater (phosphorous, nitrogen) if discharged to environmentally sensitive estuaries
what are the mechanisms that affect DO in rivers?
oxygen demanding wastes removes DO
photosynthesis adds DO during the day
plants remove DO at night
respiration of organisms living in water and sediments removed DO
tributaries add their own DO inputs and DO demands
rising water temps reduces oxygen solubility in water
winter ice blocks atmospheric recharge
Describe the lake water quality for the season of winter
lake is thermally stratified with cold (approx 0 deg) water near the surface and warmer (2-4 deg) denser waters near the bottom
Describe the lake water quality for the season of spring
As the surface waters warm toward 4 deg in spring, they become denser and sink, bringing colder waters to the surface to warm
the process of mixing by convection, aided by wind energy, circulates the water column, leading to an isothermal condition termed spring turnover
Describe the lake water quality for the season of summer
As lake waters continue to warm above 4 deg, the lake thermally stratifies. Surface waters are significantly warmer and less dense than the lower waters during summer stratification
Describe the lake water quality for the season of fall
The input of solar energy decreases and heat is lost from the lake more rapidly than it is gained.
As surface waters cool, they become denser, sink, and promote circulation through convection, aided by wind, this phenomenon called fall turnover again leads to isothermal conditions
What are the different types of air pollution?
- industrial smog
- sulfurous smog
- photochemical smog
- criteria pollutants
- inside home/workplace pollution
What are the criteria pollutants
- CO
- NOx
- SOx
- VOC
- O3
- particulate matter PMx
What happens during unstable conditions of atmospheric stability?
- vertical movement of an air parcel in atmosphere is encouraged upward or downward
- Most commonly develop on sunny days with low wind speeds
- land surface quickly absorbs heat and transfers some heat to the surface air layer, air warms becomes less dense than surrounding air so it rises vertically
What happens during stable conditions of atmospheric stability?
- vertical movement of an air parcel is discouraged
- under very stable conditions, cooler layer of air near land surface is capped by an upper warmer air layer, this called inversion and prevents vertical motion of an air parcel
what happens during neutral stability conditions of atmospheric stability?
- occurs when the environmental lapse rate is same as dry adiabatic lapse rate, vertical movement of air is neither encouraged nor supported under these conditions
- typically occurs on a windy day when cloud cover prevents strong heating or cooling of the land
what is definition of temperature inversion?
occurs when a warmer layer of air resides above a cooler surface layer
- areas prone occur where large populations of humans reside (coastal zones, valleys, locations near mtns)
What are some environmental impacts of incineration?
- Emissions (chlorinated compounds, heavy metals)
- Collected ash - contains toxic materials (may have to be treated as hazardous waste, particulate matter size important)
favorable attributes to WTE incineration
- volume reduction
- immediate disposal
- less land requirement
- destruction of hazardous materials
- energy recovery
unfavorable attributes to WTE incinceration
- potential release of toxic substances
- potential hazardous ash recovery
- public perception