Project 1: Eco Footprint Flashcards
cogeneration
the generation of electricity and other energy jointly, especially the utilization of the steam left over from electricity generation to produce heat.
ecological footprint
the impact of a person or community on the environment, expressed as the amount of land required to sustain their use of natural resources.
sustainability
avoidance of the depletion of natural resources in order to maintain an ecological balance.
bituminous coal
black coal having a relatively high volatile content. It burns with a characteristically bright smoky flame.
Contains the widest range of carbon content (45% to 86%),
mainly used as a fuel to generate electricity, though some is used as coking coal to produce steel.
The oldest and most abundant coal type found in the United States; contributes about 50% of all U.S. coal
Electric power
the rate at which electric energy is transferred to other forms of energy
Measured in Watts (W) or kiloWatts (kW)
Most energy companies measure electrical energy in kilowatt hours (kWh), or wattage used per hour (h).
1st Law of Thermodynamics
Law of Conservation of Energy
the total energy of an isolated system is constant; energy can be transformed from one form to another, but can be neither created nor destroyed.
entropy
scientific concept, as well as a measurable physical property that is most commonly associated with a state of disorder, randomness, or uncertainty.
2nd Law of Thermodynamics
Law of Entropy
Entropy predicts the direction of spontaneous processes, and determines whether they are irreversible or impossible, despite obeying the requirement of conservation of energy,
Equation for kiloWatt hours
kW x h = kWh
the major fossil fuels we use
Coal, oil, and natural gas, come from deposits of organic matter that were formed 100 million to 500 million years ago.
The energy in these fuels originally came from the sun and was converted to chemical energy through photosynthesis
These high-energy fuels were created when dead biological materials built up under layers of sediment and were exposed to heat and pressure over millions of years.
Major uses of the fossil fuels
Coal – 41% of global electricity is derived from burning coal, coal is required in steel making
Oil – gasoline for transportation, diesel oil, heating oil, petrochemical industry (plastics, chemicals, asphalt)
Natural gas – burned to generate electricity, residential heating and cooking, feedstock for plastics, transportation fuel.
Coal
A solid fuel formed from the remains of plant materials preserved 300 million to 400 million years ago.
There are four types/stages of coal
lignite
sub-bituminous
bituminous
anthracite
These stages are formed when peat, partly decomposed organic material, is compressed between layers of sediment.
Sub – bituminous coal
Lignite in which Hydrogen and oxygen has been driven off resulting in higher carbon content
Second lowest energy content, large quantities are found in thick beds near the surface, resulting in low mining cost and, correspondingly, lower prices
Lignite
Formed under least pressure and heat, but more moisture. Can contain recognizable plant structures. (brown coal)
As a result, lignite has a low carbon content (25% to 35%).
Anthracite:
Formed under the greatest pressure, high temps and low moisture. Has highest carbon content and highest heating value.
Rare in the U.S.
Scrubbers
Air pollution control devices that remove acidic gases and/or particulates from industrial exhaust streams and coal smokestacks
Wet scrubbers use a “scrubbing liquid” to trap pollutants
Dry scrubbers use dry reagents or electrical charge.
Electrostatic Precipitators
Filter particles from exhaust fumes by inducing an electrostatic charge in the particles and then attracting them to collecting plates of the opposite charge
Thermal Pollution due to burning coal
Coal burning power plants and industrial process that discharge warmer water into nearby cooler rivers can cause thermal pollution.
Warm water holds less dissolved oxygen than cooler water. (As temperatures rise fish and other aquatic species will struggle for oxygen)
Warmer water can speed up the metabolic rate of aquatic organisms leading them to deplete their food resources.
Natural Gas
methane (CH4), ethane, propane, and butane.
Mostly extracted in association with petroleum, but direct drilling for natural gas has recently been explored.
Methane is also released by anaerobic microbes in landfills, swamps, and cow’s stomach (rumen)
One way of extracting oil and natural gas is through fracking.
Fracking
the process of injecting liquid at high pressure into subterranean rocks, boreholes, etc. so as to force open existing fissures and extract oil or gas.
Environmental concerns over fracking
Requires too much water Groundwater contamination Surface water contamination Methane gas leaks (greenhouse gas 23 times as potent as CO2) Earthquakes
Why natural gas is considered a “bridge” fuel
Burning Natural gas emits 50% less CO2 into the atmosphere when compared to coal burning to produce the same amount of energy
Burning natural gas releases less impurities (mercury, SO2, NOx, Particulate matter)
Some consider it a “bridge” fuel as we transition to renewables
Petroleum
Fluid mix of hydrocarbons, water, and sulfur that occurs in underground deposits. Petroleum removed from the ground is known as crude oil
Formed when the remains of ocean-dwelling phytoplankton (microscopic algae) 50 million - 150 million years ago
Petroleum fills the pore spaces in rock over millions of years and migrates up to the highest point of the porous rock, where it is trapped by non-porous rock.
Fractional distillation of crude oil
Crude oil is heated allowing hydrocarbons of different molecular weights to be separated according to their boiling points.
Oil Sands
Not in a readily available form.
slow-flowing, viscous deposits of bitumen mixed with sand, water, and clay
can be extracted by surface mining, which has serious negative environmental impacts.
Requires large amounts of water to extract, can be inefficient, and releases more CO2 than conventional oil production
Composition of Air
Nitrogen (78%)
Oxygen (20%)
Very small amounts of argon, carbon dioxide and water vapor. (2% or less)
Troposphere
Where the air we breathe is. Extends 11Km (7 miles) high.
Responsible for weather.
Temperature decreases with altitude in the troposphere
Stratosphere
11-50 Km (7-31 miles). Very little vertical mixing of gases occurs here so pollutants can last a long time! The stratosphere contains the ozone layer. This layer protects life on Earth from receiving too much UV radiation
Mesosphere
the region of the earth’s atmosphere above the stratosphere and below the thermosphere, between about 30 and 50 miles (50 and 80 km) in altitude.
Temperature decreases as altitude increases and the mesopause is the coldest part of Earth’s atmosphere with temperatures below −143 °C (−225 °F; 130 K)
Thermosphere
the region of the atmosphere above the mesosphere and below the height at which the atmosphere ceases to have the properties of a continuous medium. The thermosphere is characterized throughout by an increase in temperature with height.
ultraviolet radiation causes Photoionization/photodissociation of molecules, create ions; the thermosphere thus constitutes the larger part of the ionosphere.
Thermospheric temperatures increase with altitude due to absorption of highly energetic solar radiation
Thermal Inversion
A reversal of the normal behaviour of temperature in the troposphere.
A layer of cool air at the surface is overlain by a layer of warmer air.
Warm air at altitude traps pollutants near the ground
Natural air pollution
volcanic ash, dust, pollen, and spores.
Primary Pollutant
one that is put directly into the air by human activity ex. Soot, CO
Secondary Pollutant
forms when two primary pollutants interact, or when one combines with a naturally occurring substance ex. ground level ozone, Sulfuric acid
Burning Fossil Fuels releases specific Air Pollutants
Complete combustion creates Carbon dioxide – the leading greenhouse gas contributing to global climate change
Incomplete combustion, where oxygen is limited, creates Carbon monoxide - a colorless, odorless gas which can interfere with the ability of red blood cells to carry oxygen resulting in CO poisoning and death.
Mercury – occurs naturally in coal and enters the air when coal is burned. Airborne mercury falls to the ground in rain. Microorganisms convert it into methylmercury, a powerful neurotoxin!
Particulate matter – Solid or liquid particles small enough to be suspended in the air causing respiratory problems when inhaled. Most PM is naturally occuring wind blown dust.
Volatile Organic Compounds (VOCs) - Released by car exhaust and naturally released by trees. These compounds can combine to form the secondary pollutant, tropospheric ozone.
Acid Rain
Although acid rain, sleet, snow, hail, can form naturally, most acid rain forms from anthropogenic sources such as the burning of fossil fuels
Coal and diesel fuel contain impurities such as sulfur which react with oxygen forming sulfur dioxide. This can react with water to form Sulfuric acid which falls back to Earth as the secondary pollutant, acid rain
Nitrogen Oxides (Nox) released in tailpipe emissions and from coal burning, can also react with water to form Nitric acid, another form of acid rain
Impacts of Acid Rain
Acidic deposition most often affect communities downwind from coal burning power plants
Acids leach minerals, such as Calcium and Magnesium, from soils altering soil chemistry and disrupting soil organisms and plant life
Toxic metal ions such as Aluminum, can be mobilized in soil affecting plant nutrient uptake
The underlying geology, for example limestone, can mitigate the impact by neutralizing the acid
Aluminum can leach from soil into waterways where it can damage fish gills and affect their salt balance
Acid rain erodes stone buildings
Industrial Smog
AKA: gray-air smog
Forms when coal or oil is burned. Mix of soot, CO, CO2, SO2
Less common in industrialized countries today due to emissions regulations
Becoming a significant problem in rapidly industrializing nations
Photochemical Smog
AKA: Brown-air smog.
Forms through light driven chemical reactions between Nitrogen Oxides (NOx) and Volatile Organic Compounds (VOCs) to produce a variety of pollutants
Car exhaust releases NO and VOCs into the air. These react in sunlight to form tropospheric (ground level) ozone and other constituents of photochemical smog
Photochemical smog levels typically peak in the afternoon and can cause irritation to the eyes, nose and throat
Health Effects of Ground level ozone
Airway irritation, coughing, and pain when taking a deep breath;
Wheezing and breathing difficulties during exercise or outdoor activities;
Aggravation of asthma and increased susceptibility to respiratory illnesses like pneumonia and bronchitis
Permanent lung damage with repeated exposures.
This is the pollutant that most often exceeds EPA NAAQS.
The Clean Air Act (1970)
The Clean Air Act gave the federal government authority to clean up air pollution.
EPA set maximum limits on pollutants that can be in the air (National Ambient Air Quality Standards)
EPA limits emissions from industry
EPA regulates vehicle emissions and required the gradual elimination of lead from gasoline
Established criteria pollutants
Criteria Air Pollutants
Carbon Monoxide (CO) Nitrogen dioxide (NO2) Sulfur Dioxide (SO2) Particulate Matter (PM) Troposheric (ground level) ozone (O3) Lead (Pb)
Primary Treatment of Waste Water
Screens and grates remove large objects
Solid waste settles to the bottom of the tank
Oil and grease removed
Tragedy of the Commons
The tragedy of the commons is a situation in which individual users, who have open access to a resource unhampered by shared social structures or formal rules that govern access and use, act independently according to their own self-interest and, contrary to the common good of all users, cause depletion of the resource through their uncoordinated action.
What is an environmental system?
a set of interacting components which exchange energy and matter so that a change in one part of the system effects other part(s) of the system. (Ex:,digestive system, ecosystem, car, etc.)
pH
logarithmic scale that indicates strength of acids and bases in a solution on a range of 0 to 14
law of conservation of matter
states that matter can neither be created nor destroyed; it can only change form
energy
ability to do work, or transfer heat (power / time) measured in kiloWatt-hours
joule
amount of energy used by a 1-watt lightbulb when turned on for 1 second
power
rate at which work is done (energy / time) measured in kiloWatts
energy efficiency
ratio of the amount of work done to the total amount of energy first put into a system
energy quality
the ease at which an energy source can be used for work; high quality is concentrated and easily transported, low quality is less concentrated and less easily transported
open system
system which can exchange matter and energy across other system boundaries
closed system
system where matter and energy exchanges do not occur
feedback
a system’s adjustments to input or output rates in response to a change in the system
negative feedback loop
system’s response to a change through returning to its original state or changing the rate at which the change occurs; RESISTS change
it causes the output of a system to be lessened; so, the feedback tends to stabilize the system.
Examples: Population of predators and prey - If the numbers of prey decrease, then some predators will starve, and their numbers will decrease.
Greenhouse effect - More radiation escapes into space from the upper atmosphere than from the lower portion. Global warming will reduce the rate of this escaping radiation, and this will lessen the greenhouse effect.
positive feedback loop
a system’s cycle that AMPLIFIES change
A positive feedback loop occurs in nature when the product of a reaction leads to an increase in that reaction. If we look at a system in homeostasis, a positive feedback loop moves a system further away from the target of equilibrium.
Examples: Clotting factors are released to seal a wound
At the time of baby birth, there is a dilation of the walls of the uterus that causes a contraction that encourages further stretching (this continues until birth)
In fruit ripening, there is the release of ethylene, which will continue the ripening process of fruits
Five Key Global Indicators
- Biodiversity
- Food production
- Average global temperature and CO2 concentration
- Human population
- Resource depletion
Types of biodiversity
- genetic
- species
- ecosystem
Background extinction rate
The average rate at which species become extinct over a long term
Converting between acres and hectares
1 ha = 2.5 acres
Greenhouse gases
Gases in the atmosphere that trap heat near the surface
CO2
methane - CH4
nitrous oxide - N2O
fluorinated gases - HFC (hydrofluorocarbons - ozone depleting) and CFC (chloroflurocarbons - better than HFC’s)
