Old, differently formatted notes (unit 9)

Unit 9

Ozone Depletion

Formation of Ozone

O2 + UV-C = O + O
O + O2 → O3 (ozone)

• Ozone layer: A layer of ozone gas in the Earth's stratosphere

• Formation: Ozone is formed through the interaction of oxygen molecules and ultraviolet (UV) radiation

• Ozone formation process: UV radiation splits oxygen molecules (O2) into individual oxygen atoms, which then react with other oxygen molecules to form ozone (O3)

• Importance: The ozone layer absorbs most of the Sun's harmful UV radiation, protecting life on Earth from its damaging effects

• Ozone depletion: Human activities, such as the release of chlorofluorocarbons (CFCs), can lead to the destruction of ozone molecules, causing a thinning of the ozone layer

• Montreal Protocol: An international agreement aimed at phasing out the production and use of ozone-depleting substances to protect the ozone layer

Effects

• Human activities primarily cause ozone depletion.

• Key human activities that contribute to ozone depletion include the release of chlorofluorocarbons (CFCs), halons, carbon tetrachloride, and other ozone-depleting substances.

• Ozone depletion leads to increased ultraviolet (UV) radiation levels reaching the Earth's surface.

• Increased UV radiation can harm human health, such as skin cancer, cataracts, and weakened immune systems.

• Efforts to reduce ozone depletion include the Montreal Protocol, which aims to phase out the production and use of ozone-depleting substances.

Greenhouse Effect

Greenhouse gases (GHGs)

• GWP : The global warming potential standard

• CO2 has a GWP of 1 (mostly abundant and this portion of greenhouse gases is the biggest contributor)

• CFCs are found in coolants with a GWP of 4,000 to 10,000

  • These CFCS were soon switched to HFCS which has a GWP of 12,000 but is less harmful to the ozone layer

• N2O is nitrous oxide found in agricultural systems

• CH4 is methane which is released by cows

An increase in GHGs has led to an increase in global temperatures which is pretty much climate change

1. Some solar radiation reflects off the atmosphere and some is absorbed by the ground (soil or oceans)

2. Infrared (heat) is released out to space

3. Greenhouse gases trap heat in the troposphere (natural process)

4. Excess greenhouse gases trap heat in our atmosphere causing the earth to warm

Global Effects

Melting Ice Caps

• Ice is a habitat

  • Land ice is melting, ice has a high albedo

Albedo is how well something can reflect sun rays

• Soil is exposed which has low albedo

• Permafrost is melting which releases methane through decomposition

Invasive Species

Organisms that can now live where they couldn’t before

Heatwaves

High temperatures lasting for a week or more

Extinction

Organisms that lose their habitat

Forest Fires

Hot dry climates increase the risk of forest fires

Sea Level Rises and Flooding

ice melts, sea levels rise causing permanent flooding

Drought

Higher temperatures mean increased evaporation which results in more drought

Severe Weather

Higher temperatures lead to more evaporation causing more precipitation

Bleached Coral Reefs

Coral gets stressed easily, spitting out algae causing the coral to bleach

Impacts of Ocean Acidification

Ecosystem Impacts

Oceans have absorbed most of the greenhouse gasses because there is mostly ocean which leads to the oceans becoming warmer mainly in the Arctic, this causes ocean land ice to melt, thermal expansion of water, habitat loss

habitats are lost because animals can’t live in the warmer water and coral becomes stressed

Ocean Acidification

pH has fallen by .1 in the ocean, going from 8.2 to 8.1 (30% increase in acidity) this causes shells to dissolve that are made out of calcium carbonate because the hydrogen ion gets in the way of the carbonate bonding

Shells dissolve due to ocean acidity as the increased concentration of hydrogen ions in the water reacts with the calcium carbonate in the shells, resulting in their dissolution.

The chemical formula for ocean acidity is not a single compound, but rather a measure of the concentration of hydrogen ions (H+) in seawater. When hydrogen ions combine with water (H2O), they form hydronium ions (H3O+), which can contribute to the acidification of the ocean. The process of ocean acidification can have detrimental effects on marine organisms, including shell destruction in some species.

Different Species

Native species is a group of organisms that nurmally live in an area

An introduced species is an organism that is not native to an area and is most likely brought over by humans

Invasive species are organisms that are not native that dosedamage to an ecosystem

Human Impact on Biodiversity

Habitat loss

*1 largest factor

Solution: habitat horridord for our animals to move around within protected areas

Invasive speices

Invasive species are harmful because they disrupt ecosystems by outcompeting native species for resources and altering habitats. They are non-native organisms that can cause economic and environmental damage.

Polution

Pollution has detrimental effects on human impact on biodiversity as it can contaminate air, water, and soil, leading to the destruction of habitats, the decline of species populations, and the disruption of ecosystems.

Population

The increase in human population leads to habitat destruction, pollution, and overexploitation of resources, which negatively impacts biodiversity by reducing species diversity and causing species extinction.

Climate Change

Climate change negatively affects biodiversity by altering ecosystems, causing habitat loss, disrupting species interactions, and increasing the risk of extinction for many plant and animal species.

Over Harvesting

Poaching (Killing an organism for a part of it's body)

Overharvesting is harmful to biodiversity as it depletes populations of species, disrupts ecosystems, and can lead to the extinction of certain organisms.

Unit 6

Energy Resources

Non-Renewable

Finite amount of a material

Nuclear Energy

Nuclear energy is the energy released from the splitting or combining of atomic nuclei, typically through nuclear reactions, which can be harnessed to generate electricity.

Coal

Coal energy is produced by burning ancient plant remains called coal. It releases heat energy for electricity and heat production. However, coal has environmental drawbacks. It emits carbon dioxide, contributing to climate change, and pollutants like sulfur dioxide, nitrogen oxides, and particulate matter, causing air pollution and respiratory issues.

Oil

Oil energy is versatile, serving various purposes like transportation, electricity generation, and heating. It is refined into fuels for vehicles and burned in power plants to produce electricity. Additionally, oil is used for heating and plays a crucial role in producing plastics, lubricants, and chemicals. Overall, oil energy is vital for powering our modern society.

Natural Gas

Natural gas is used for energy by being burned to produce heat, which is then used to generate electricity or provide heat for residential, commercial, and industrial purposes.

Renewable

Biomass

Biomass is organic matter, like plants and wood, used for renewable energy. It can become biofuels or be burned for heat/electricity. It's renewable because it comes from living organisms. It's a sustainable alternative to fossil fuels, reducing emissions. Environmental benefits depend on factors like source, production, and land use.

Hydropower

Hydropower uses flowing or falling water to generate electricity. It is renewable because it relies on the continuously replenished water cycle. Water is collected in reservoirs and released through turbines, which spin generators to produce electricity. Unlike fossil fuels, hydropower is sustainable, and clean, and does not deplete natural resources or produce greenhouse gas emissions. It can help reduce carbon emissions and combat climate change.

Solar

Solar energy converts sunlight into electricity through photovoltaic cells. It is a renewable resource with advantages like low maintenance and cost-effectiveness. In the US, the Department of Energy promotes solar energy development and adoption to transition to cleaner and sustainable energy.

Geothermal

Geothermal energy is heat derived from the Earth's internal heat. It is a renewable energy resource because it is continuously replenished by the natural heat of the Earth. This energy can be harnessed by drilling wells to access hot water or steam, which can then be used to generate electricity or for direct heating purposes. Geothermal energy is considered renewable because the heat within the Earth is virtually limitless and will continue to be produced as long as the Earth exists.

Fracking

Fracking, short for hydraulic fracturing, is a method used to extract natural gas and oil from deep underground. It involves injecting a mixture of water, sand, and chemicals at high pressure into rock formations to release the trapped gas or oil. Fracking has both environmental benefits and concerns.

On one hand, it has contributed to increased energy production and reduced reliance on foreign oil. On the other hand, it poses potential risks to the environment. These risks include water contamination, air pollution, habitat disruption, and induced seismic activity. The long-term effects of fracking on ecosystems and human health are still being studied.

Coal Powerplant

A coal power plant generates electricity by burning coal to produce steam, which drives a turbine connected to a generator.

1. Coal is mined from underground or surface mines and transported to the power plant.

2. The coal is pulverized into a fine powder to increase its surface area, allowing for efficient combustion.

3. The pulverized coal is then blown into the combustion chamber of a boiler.

4. In the boiler, the coal is burned at high temperatures, releasing heat energy.

5. The heat energy converts water into steam in the boiler tubes.

6. The high-pressure steam is directed towards the turbine blades, causing them to spin.

7. As the turbine blades rotate, they turn a shaft connected to a generator, producing electricity.

8. After passing through the turbine, the steam is condensed back into water in a condenser.

9. The condensed water is then returned to the boiler to be heated and converted into steam again.

10. The generated electricity is sent to the power grid for distribution to homes, businesses, and industries.

Nuclear Powerplant

The process of a nuclear power plant can be summarized in the following steps:

1. Nuclear Fuel: Uranium or plutonium fuel is used in the reactor core. These fuel rods undergo a process called fission, where the atoms split and release energy.

2. Nuclear Reaction: The fission process generates heat and produces high-energy neutrons. These neutrons collide with other uranium atoms, causing a chain reaction.

3. Heat Generation: The heat produced from the nuclear reaction is used to convert water into steam. This is done in the reactor's primary cooling system.

4. Steam Turbine: The high-pressure steam drives a turbine, which is connected to a generator. As the turbine spins, it generates electricity.

5. Cooling System: After passing through the turbine, the steam is condensed back into water using a cooling system. This water is then recycled back into the primary cooling system.

6. Electricity Distribution: The electricity generated by the generator is sent to a transformer, which increases the voltage for efficient transmission. It is then distributed through power lines to homes, businesses, and industries.

Hydroelectric Dam Powerplant

A hydroelectric dam power plant operates in the following steps:

1. Water Intake: Water is collected from a river or reservoir and directed towards the dam.

2. Dam: The dam is a large structure built across a river to create a reservoir. It stores a large amount of water at a higher elevation.

3. Penstock: The water flows through a penstock, which is a large pipe or tunnel, from the reservoir to the turbine.

4. Turbine: The high-pressure water from the penstock strikes the blades of a turbine, causing it to spin.

5. Generator: The spinning turbine is connected to a generator, which converts mechanical energy into electrical energy.

6. Transmission: The electricity generated is transmitted through power lines to homes, businesses, and industries.

7. Release of Water: After passing through the turbine, the water is released downstream, maintaining the natural flow of the river.

8. Control Systems: Various control systems monitor and regulate the flow of water, turbine speed, and electricity output for efficient operation.

Run-Off River Hydroelectric Powerplant

A run-of-river hydroelectric power plant is a type of hydroelectric power plant that harnesses the energy of flowing water in a river without the need for a large reservoir. Here are the steps involved in the operation of a run-of-river hydroelectric power plant:

1. Diversion: A portion of the river's flow is diverted using a weir or dam, creating a channel or canal that directs the water towards the power plant.

2. Intake: The diverted water is then channeled into an intake structure, which may include screens to prevent debris from entering the system.

3. Penstock: The water is then conveyed through a penstock, a large pipe or conduit, which carries the water from the intake to the turbine.

4. Turbine: The water flows through the penstock and strikes the blades of a turbine, causing it to rotate. The turbine converts the kinetic energy of the flowing water into mechanical energy.

5. Generator: The rotating turbine is connected to a generator, which converts the mechanical energy into electrical energy. The generator consists of coils of wire that rotate within a magnetic field, producing an electric current.

6. Transmission: The generated electricity is then transmitted through power lines to the electrical grid or to nearby consumers.

7. Return to the river: After passing through the turbine, the water is returned to the river downstream of the power plant, maintaining the natural flow of the river.

Tidal Energy Powerplant

The operation of a tidal energy power plant can be explained in the following steps:

1. Tidal Variation: The power plant is located in an area with significant tidal variations, such as a bay or estuary, where the rise and fall of tides are substantial.

2. Barrage Construction: A barrage, which is a dam-like structure, is built across the tidal inlet. It consists of sluice gates or turbines that can capture and control the flow of water.

3. Tidal Flow: As the tide rises, water flows into the tidal basin through the barrage openings. During high tide, the sluice gates or turbines remain closed.

4. Ebb Tide: As the tide begins to recede, the sluice gates or turbines are opened, allowing the water to flow out of the tidal basin. This creates a pressure difference between the basin and the sea.

5. Turbine Operation: The ebb tide causes the water to flow back through the turbines, which are connected to generators. The turbines spin, converting the kinetic energy of the flowing water into mechanical energy.

6. Electricity Generation: The mechanical energy is then converted into electrical energy by the generators. This electricity can be transmitted to the grid for distribution to consumers.

7. Tidal Reversal: As the tide changes and starts to rise again, the sluice gates or turbines are closed to prevent water from flowing back into the tidal basin.

8. Environmental Considerations: Tidal power plants must be designed and operated with consideration for the local ecosystem, including fish migration patterns and potential impacts on marine life.

Active Solar System

Active solar system energy refers to the utilization of solar energy through mechanical or electrical devices. Here are the steps involved in harnessing active solar system energy:

1. Collection: Solar panels or collectors are used to capture sunlight. These devices are typically made of photovoltaic cells or solar thermal collectors.

2. Conversion: In photovoltaic systems, sunlight is converted directly into electricity through the photovoltaic effect. Solar thermal systems convert sunlight into heat energy, which can be used for various purposes like heating water or generating steam.

3. Storage: Energy storage systems, such as batteries or thermal storage tanks, are used to store excess energy generated during periods of high solar availability. This stored energy can be used during times when sunlight is limited.

4. Distribution: The converted energy is distributed to the desired location or used locally. In the case of electricity, it can be fed into the grid or used to power electrical devices directly.

5. Monitoring and Control: Various sensors and control systems are employed to monitor the performance of the solar system, optimize energy production, and ensure safety.

Passive Solar Home Design

Passive solar home design is an architectural approach that utilizes the sun's energy to provide heating, cooling, and lighting for a building. It involves strategic placement of windows, insulation, and thermal mass to maximize the use of natural sunlight and minimize the need for mechanical systems. Key principles include orienting the building to capture the sun's rays, using shading devices to control solar gain, and incorporating thermal mass materials to store and release heat. This design approach reduces reliance on fossil fuels, decreases energy costs, and promotes sustainability.

Photovoltaic Panels (Solar Panels)

1. Solar panels, also known as photovoltaic (PV) panels, convert sunlight into electricity using the photovoltaic effect.

2. The process starts with the solar panels absorbing sunlight, which consists of photons.

3. The photons excite the electrons in the solar cells, causing them to move and create an electric current.

4. The direct current (DC) electricity generated by the solar panels is then converted into alternating current (AC) electricity using an inverter.

5. The AC electricity is then used to power electrical devices or can be fed into the electrical grid.

6. To install solar panels, they are typically mounted on rooftops or in open areas with maximum exposure to sunlight.

7. Proper wiring and electrical connections are made to ensure the generated electricity can be utilized effectively.

8. Regular maintenance, such as cleaning the panels and checking for any damage or malfunctions, is important to ensure optimal performance.

9. Solar panels are a renewable energy source, providing clean and sustainable electricity while reducing reliance on fossil fuels.

Wind Power

Wind power can be explained in the following steps:

1. Wind is a form of renewable energy that is harnessed by using wind turbines.

2. The first step is to identify a suitable location with consistent and strong wind patterns.

3. Wind turbines are then installed in these locations. These turbines consist of large blades that rotate when the wind blows.

4. As the blades rotate, they spin a generator, which converts the kinetic energy of the wind into electrical energy.

5. The electricity generated by the wind turbines is then transmitted through power lines to homes, businesses, and industries.

6. To ensure efficient operation, regular maintenance and monitoring of the wind turbines are necessary.

7. The electricity produced from wind power is a clean and sustainable source of energy, as it does not produce greenhouse gas emissions or contribute to air pollution.

Geothermal Powerplant

A geothermal power plant is a facility that harnesses the heat from the Earth's core to generate electricity. Here are the steps involved in the operation of a geothermal power plant:

1. Resource Identification: Identify areas with geothermal potential through geological surveys and exploration.

2. Well Drilling: Drill deep wells into the Earth's crust to access the geothermal reservoirs. These wells typically range from a few hundred to several thousand feet deep.

3. Reservoir Extraction: Hot water or steam is extracted from the geothermal reservoirs through production wells.

4. Power Generation: The extracted fluid is used to drive a turbine, which is connected to a generator. The turbine converts the kinetic energy of the fluid into mechanical energy, and the generator converts this mechanical energy into electricity.

5. Fluid Re-injection: After energy extraction, the cooled fluid is re-injected back into the geothermal reservoir through injection wells. This helps sustain the reservoir's pressure and ensures long-term resource availability.

6. Power Transmission: The generated electricity is transmitted through power lines to homes, businesses, and industries for consumption.

7. Environmental Considerations: Geothermal power plants have minimal greenhouse gas emissions and a small physical footprint. However, careful monitoring is necessary to prevent the release of potentially harmful gases and to manage the disposal of any byproducts.

Hydrogen Powered Car

A hydrogen-powered car, also known as a fuel cell vehicle (FCV), works by converting hydrogen gas into electricity through a process called electrolysis. Here's a simplified explanation of how it works:

1. Hydrogen gas (H2) is stored in high-pressure tanks in the car.

2. The hydrogen gas is then fed into a fuel cell stack, which contains multiple fuel cells.

3. Each fuel cell consists of an anode, a cathode, and an electrolyte membrane.

4. At the anode, hydrogen gas is split into protons (H+) and electrons (e-).

5. The protons pass through the electrolyte membrane, while the electrons are forced to travel through an external circuit, creating an electric current.

6. The electric current can be used to power the car's electric motor and other components.

7. At the cathode, oxygen from the air combines with the protons and electrons to form water (H2O), which is the only byproduct of this process.

8. The water vapor is released as the car's exhaust.

Unit 7

Air Pollution

Sources

Point air pollution: Where you can point to where the pollution is happening.

Nonpoint Air pollution: Larger area of pollution (cars in a city)

Natural: Pollen, volcanos, and dust storms

Anthropogenic: Combustion of fossil fuels

Primary Vs. Secondary

Pollutants

Reducing Air Pollution

1. Regulate air pollution: (Tax breaks), Policies (ideal free zones), and laws (Clean air act)

2. Conserve and reduce fossil fuel use

3. Alternative fuels: Wind and solar

Clean Air Act

Sets standards for the six criteria for air pollutants

• Limits emissions from industry and transportation

• Funds pollution research

Decreasing Vehicle Pollution

Vapor Recovery Nozzle

A tube inside gas nozzles that sends VOCS to an underground tank

Catalytic Converter

Required on all cars since 1975

Reduces harmful emissions by converting toxic gases like carbon monoxide and nitrogen oxides into less harmful substances like carbon dioxide and nitrogen through chemical reactions with a catalyst.

Decreasing Industrial Pollution

Scrubber

A scrubber works by passing polluted air through a liquid or solid material to remove pollutants before releasing it into the atmosphere. The pollutants are absorbed or chemically reacted with the scrubbing material, reducing industrial pollution.

Electrostatic Precipitator

An electrostatic precipitator reduces industrial pollution by using electric charges to attract and capture particles like dust and smoke from the air. The charged particles are then collected on plates or filters, preventing them from being released into the atmosphere.

Photochemical Smog and Thermal Inversions

How is NOx created?

NOx is created through the combustion of fossil fuels in vehicles, power plants, and industrial processes. It forms when nitrogen and oxygen in the air react at high temperatures.

What have scientists found that people exposed to high levels of NOx may suffer from?

Lung disease, heart disease, asthma, plants can be affected

What is the equation for photochemical smog

Photochemical Smog: (NO + VOC + UV + O2 → O3 + PANS

NO + VOCs come from urban areas with many cars

NO is highest in the morning

O3 is highest in the afternoon

UV: Environment

O3 + PANS: Secondary

Temperature Inversion

• Normal Temperature Gradient: Temperature decreases with increasing altitude.

• Inversion: Temperature increases with increasing altitude, trapping pollutants.