ENGR 202 Review: Intro to Sustainable Development & Environmental Issues

Posted on Sep 3, 2024 in Geology

ENGR 202 – Review Sheet

Introduction to Sustainable Development and the Role of Engineers

What is “The Environment”?

The environment is the aggregate of surrounding things, conditions, or influences, especially as affecting the existence or development of someone or something. This generally refers to the physical environment around us; the air we breathe, the water we drink, and the lands, oceans, rivers, and forests that cover the earth.

Categories of Anthropogenic Environmental Change

1. Changes associated with land use.
2. Changes induced by emissions or from products and industrial processes.

What is the Role of Engineering in Environmental Issues?

Engineers are primarily involved in problems related to technology development and deployment. Engineers also design and build all the manufacturing processes, industrial technology, and transportation infrastructure needed to extract, transport, and refine raw materials; fabricate products; and distribute the goods and services of modern societies worldwide.

Sources of Environmental Impacts

1. Materials Selection
2. Manufacturing Processes
3. Energy Use

What is Industrial Ecology?

Industrial ecology is the means by which humanity can deliberately and rationally approach and maintain a desirable carrying capacity, given continued economic, cultural, and technological evolution. The concept requires that an industrial system be viewed not in isolation from its surrounding systems, but in concert with them. It is a systems view in which one seeks to optimize the total materials cycle from virgin material, to finished material, to component, to product, to obsolete product, and to ultimate disposal. Factors to be optimized include resources, energy, and capital. (Essentially the application of the Life Cycle Analysis)

What is Sustainable Development?

Sustainable development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs.

What is Environmental Engineering?

Environmental engineering is the application of science and engineering principles to improve the environment, hence allowing future generations to meet their own needs.

Overview of Environmental Issues

Air Pollution

Basis for Environmental Concerns

• Human Health
• Human Welfare

Classification of Human Health Effects

• Acute – Short-term exposure results in an immediate response in the human body.
• Chronic – Long-term exposure results in a long-term response in the human body.
• Carcinogenic – Exposure leads to cancer.

Classification of Human Welfare Effects

Aesthetic qualities such as good visibility free from air pollution.

Things that Affect the Air

General (Specific):

• Particulate Matter (Diesel Combustion, Mills)
• Sulfur Dioxide (Combustion of coal and oil)
• Carbon Monoxide (Carbon-containing materials are not completely combusted)
• Nitrogen Oxides (Fuel Combustion and Industrial Chimneys)
• Tropospheric Ozone (Photochemical reactions between sunlight and nitrogen oxides)
• Lead (Combustion of Leaded Gasoline)

What is Particulate Matter?

Particulate matter refers to a mixture of small solid or liquid particles suspended in the air.

• Cardiovascular, Lung Disease, Carcinogenic

What is Sulfur Dioxide?

SO₂ is emitted primarily from the combustion of coal and oil, which contain sulfur as an impurity.

• Respiratory problems, Asthma, Acid Rain

What is Carbon Monoxide?

CO is a colorless, odorless gas that is produced when fossil fuels or other carbon-containing materials are not completely combusted.

• Dizziness, lack of breath, asphyxiation, and death

What are Nitrogen Oxides?

Nitrogen oxides oxidize in the atmosphere to form Nitrogen dioxide (NO₂), which is a reddish-brown gas that is toxic in very high concentrations. Nitrogen oxides are primarily produced through fuel combustion.

• Toxic in high concentrations, irritant in low concentrations, acid rain.

What is Tropospheric Ozone?

Tropospheric ozone or ground-level ozone is formed from complex chemical reactions in the atmosphere involving nitrogen oxides and hydrocarbon gases. These chemical reactions are triggered by summer sunlight, which provides the energy to initiate the photochemical reactions.

• Oxidant, Extremely reactive and corrosive (in high levels)

What is Lead?

Lead is a heavy metal that can cause neurological damage and adverse effects on organs such as the liver and kidneys. It is mainly produced through the combustion of leaded gasoline.

• Immediate damage to the liver and kidneys, especially to children and seniors.

What is Acid Rain and How is it Produced?

Acid rain (also known as acid deposition) refers to the fallout of acidic particles through precipitation. Acid rain is produced when sulfur oxides (SO_x) and nitrogen oxides (NO_x) react with water in the atmosphere to form sulfuric acid and nitric acid. The sulfur and nitrogen oxides are primarily released through the burning of fossil fuels.

Effects of Acid Rain

• Acidification of freshwater lakes and streams and result in the death of aquatic organisms.
• Contributes to the decline of some species of trees.
• Soil acidification disrupts the complex soil chemistry that provides nutrients to vegetation and indirectly affects soil erosion, sedimentation of waterways, and changes in animal habitat.
• Deterioration of some building materials and monuments made of limestone or marble.

What is Stratospheric Ozone Depletion?

Stratospheric Ozone Depletion is the depletion of the ozone by human-made chemicals, most notably the family of compounds known as chlorofluorocarbons.

Water Pollution

Things that Affect Water

General (Specific):

• Pathogens (Human and animal feces)
• Organic matter/waste (biodegradable organic wastes)
• Nutrients (Agriculture and Detergents)
• Toxic Organic Chemicals (Synthetic Organic Compounds)
• Toxic Metals (Mercury, Arsenic, Lead)
• Sediments (Land Erosion from human activities)
• Acidity (Sulfuric acid, when sulfur-bearing minerals react with water)
• Salts (industrial and municipal discharges)
• Heat (Electric Power Plants)

What are Pathogens?

Pathogens are disease-causing agents such as bacteria, viruses, protozoa, and parasitic worms called helminths. These microorganisms are commonly found in the intestines of infected people or animals and are then excreted in the feces that enter the sewer systems or fall onto the ground.

• Typhoid, diarrhea, cholera, etc.

What are Organic Wastes?

Organic wastes are the main source of oxygen-depleting substances in surface water. (Biodegradable chemicals)

What are Nutrients?

Nitrogen and phosphorus are two essential nutrients needed to support vegetation and other forms of life. These chemicals are widely used in fertilizers and household detergents.

• Over-enrichment of nutrients in lakes, rivers, or streams that leads to a condition called eutrophication.

What are Toxic Organic Chemicals?

Synthetic organic chemicals, which contain additional substances like chlorine, are potentially toxic to people, plants, and animals.

What are Toxic Metals?

Mercury, lead, arsenic; The health of humans and other living organisms requires trace levels of certain heavy metals such as: chromium, cobalt, copper, iron, manganese, molybdenum, vanadium, strontium, and zinc.

What are Sediments and Suspended Solids?

Sediment consists of soil particles that enter a water body and eventually settle to the bottom.

What is Acidity?

Acidity is a key factor in water’s ability to support aquatic life. Chemically, acidic water reflects a high concentration of hydrogen ions in solution. pH > 7 → Basic or Alkaline, pH < 7 → acidic.

What are Salts?

Salts refer to compounds of elements, including calcium, magnesium, sodium, and potassium, that produce positively charged ions in solution. Salts dissolve naturally into water bodies as water flows over rocks and soils. Human-made sources enter waterways via industrial and municipal discharges and urban runoff.

What is Implied by Heat?

Thermal pollution, primarily from waste heat generated at electric power plants, creates a plume of warmed water that can be detrimental to fish and plant life.

Percentage of Leaking Underground Gasoline Storage Tanks

12%

Standards for Drinking Water

• Total Coliform bacteria
• Fecal Coliform and E. Coli

Solid and Hazardous Wastes

Things that Affect the Soil

General (Specific):

• Solid Waste (Paper and paperboard)
• Hazardous Waste (Wastewater treatment)
• Radioactive Waste (Uranium mining, milling, and refining)

What are Solid Wastes?

Solid wastes, also known as non-hazardous wastes, are wastes that have not been designated as Hazardous wastes.

• There are municipal solid wastes and they are generated by residences, commercial buildings, and institutional institutions; and
• There are Industrial Wastes and they are generated by industrial activities.

What is Hazardous Waste?

Hazardous waste is a solid waste or combination of solid wastes which because of quantity, concentration, or physical, chemical, or infectious characteristics may:

1. Cause, or significantly contribute to, an increase in mortality or an increase in serious irreversible, or incapacitating reversible illness; or
2. Pose a substantial present or potential hazard to human health or the environment when improperly treated, stored, transported, or disposed of, or otherwise managed.

Characteristics of Hazardous Waste

• Ignitability – An ability to burn easily or cause or enhance fires.
• Corrosivity – Strong acids and bases, or substances able to corrode metal.
• Reactivity – An ability to react violently or cause explosions, including reactions with water.
• Toxicity – An ability to threaten water supplies and health, as determined by a laboratory test of leach-ability.

What is the Toxicity Characteristic Leaching Procedure?

If the metals and other chemical compounds specified in the TCLP are leached in amounts above specified thresholds, the material is considered toxic and hence hazardous.

What are Radioactive Wastes?

Two key attributes distinguish radioactive wastes:

1. Its harmful effects on living organisms are induced by radiation rather than by chemical mechanisms; and
2. Radioactive wastes remain dangerous for up to hundreds of thousands of years.

What is High-Level Radioactive Waste?

High-level radioactive waste is the most dangerous. High-level waste is characterized not only by the intensity of its radioactivity but also by its very long half-life.

What is Transuranic Waste?

Waste containing more than 100 nanocuries of alpha-emitting transuranic isotopes per gram of waste with half-lives greater than 20 years, except for high-level waste. All TRU elements are heavier than uranium, have several isotopes, and are typically man-made.

What is Low-Level Radioactive Waste?

Any radioactive waste that is not officially classified as high-level waste, transuranic waste, or by-product waste from uranium mining and milling is called low-level waste.

Purposes for Humanity’s Use of Natural Resources

1. As a source of food.
2. As a source of energy, and
3. As a source of raw materials for structures, devices, and other human endeavors.

Categories of Natural Resources

• Renewable resources – Which have the capability to be replenished.
• Non-renewable resources – Which exist only in finite amounts.

What is Environmental Impact?

Environmental impact is a term used to describe some of the broader implications of human activities for the environment.

What is an Ecosystem?

The term ecosystem is used to refer to any biological community that functions as a cohesive unit within its physical environment.

Global Warming and Greenhouse Effect

Greenhouse Gases (Not Including the Most Important)

• CO₂ Carbon Dioxide (important)
• CH₄ Methane (important)
• N₂O Nitrous Oxide (Laughing gas)
• CFC-11, CFC-12, CFC-113, Halocarbons
• O₃ Tropospheric Ozone

Definition of Climate

Climate is not synonymous with weather. It is more commonly defined as the “average” weather, patterns typically over a 30-year averaging period. Climate is determined by complex interactions of many factors that together constitute the global climate system.

What is Heat Flux?

The heat flux is the expression of radiative energy in terms of the rate per unit surface area:

Heat flux = (Total Rate of heat flow)/(Total surface area) (W/m²)

q = Q/A

Radiative Heat Transfer from a Black Body

q = 5.67(10^-8) T⁴

Where T is the temperature in Kelvins (Celsius + 273)

Earth’s Average Temperature Without the Greenhouse Effect

-19 degrees Celsius, the average temperature of the earth, however, is 15 degrees Celsius.

Explanation of the Greenhouse Effect

The greenhouse effect is the trapping of radiation within the atmosphere, which warms the planet. Just as in a greenhouse, most of the incoming radiation (as ultraviolet) gets through to warm the earth’s surface, and most of the outgoing radiation (as Infrared) is blocked or absorbed by the atmosphere. Gases that absorb infrared radiation are defined as greenhouse gases.

What is the Tropopause?

The Tropopause is the upper boundary of the troposphere approximately 10km above the Earth’s surface.

What is Radiative Forcing?

The term radiative forcing is used when any change in the net radiative balance will force the climate system to readjust so as to ultimately restore equilibrium.

∆F = ∆q (out or in)

Factors Affecting Radiative Forcing

• Wavelength
• Speed
• Frequency

Determining Net Forcing from Atmospheric Changes

∆F = ∆q out – ∆q in

Where

∆q out = (W/m² outgoing initially) – (W/m² outgoing after perturbation)

∆q in = (W/m² incoming initially) – (W/m² incoming after perturbation)

Finding Equivalent CO₂ Concentration

C equi (ppmv CO₂) = C₀ e ^{(∆Ftotal/6.3)}

What is the Climate Sensitivity Factor γ?

The climate sensitivity factor is known as the ratio of the final temperature change, ∆T_e, to the change in radiative forcing, ∆F rad:

γ = ∆T_e / ∆F rad

Climate sensitivity is an important parameter in climate modeling. It relates the net change in radiative forcing caused by greenhouse gases and aerosols to the resulting change in the earth’s average temperature.

Calculating Time Lag and Temperature Commitment

1. Equilibrium temperature = (percent change)(CO₂ change (i.e. doubling))

∆T_e = (∆%)(T eq)

Time lag = (time final) – (time initial)

∆t lag = t eq – t

Temperature commitment = (CO₂ change (i.e. doubling)) – (Equilibrium temperature)

∆T commit = T eq – T_e

Location of Climate Change Tests

Vostok, Antarctica.

Emission Reduction Needed to Stabilize Atmospheric CO₂ Levels

The international goal of stabilizing atmospheric CO₂ levels will require anthropogenic emissions to be roughly 60 to 80% below the 1990 emission rates.

Typical Carbon and Energy Content of Fossil Fuels

Energy Source	Carbon Content (%)	Heating Value (kJ/g)	Carbon Intensity (g C/MJ)
Natural Gas	74	54.4	13.7
Crude Oil	85	44.3	19.2
Coal	59	24.2	24.4

Measuring Carbon Content and Mass of Carbon Emitted

1. 1 mass unit of C = 44/12 = 3.667 mass units of CO₂
2. Mass of Carbon emitted = (wt%C / 100) (Mass of fuel burned)
3. Mass of carbon emitted = (Energy use) (Carbon intensity)

Measuring Carbon Intensity of Fuels

1. Carbon intensity = (Fuel carbon mass) / (Fuel Energy)
2. Carbon intensity = (Fraction of C in fuel) / (Fuel heating value)

Factors Affecting CO₂ Emissions Growth

• Population Growth per year – This reflects the size of the population and the effect of population growth. Increasing population generates greater demand for food, clothing, shelter, and other human needs.
• GDP per Capita – This measures average affluence. As this term grows, an individual’s demand for goods and services also grows.
• Energy Intensity (energy use / per GDP) – This is most related to technology and technological change.
• CO₂ emissions per unit energy – This depends principally on how the energy is being generated.

Multiply all of these together to get the CO₂ Emissions Growth.

What is Carbon Sequestration?

Carbon sequestration is the natural ability of biomass to absorb CO₂ from the atmosphere. This, however, cannot achieve the sizeable long-term reductions needed to stabilize atmospheric concentrations in the face of global energy demands.

Greatest Failures of the International Society to Date

• Kyoto Protocol
• Copenhagen

Life Cycle Assessment

Inventory Analysis

• Listing of all inputs (raw materials, energy) and outputs (products, wastes, energy).
• Qualification of each input and output.

Impact Analysis

• Listing of effects on the environment for each input and output identified in inventory analysis.
• Qualitative and/or quantitative description of impacts: adverse effects on human health and welfare, ecosystems, and materials as well as resource depletion.

Improvement Analysis

• Listing of needs and opportunities to reduce adverse effects identified in impact analysis and inventory analysis.
• Qualitative and/or quantitative description of improvements.

Human Exposure to Toxic Metals

Principal Routes of Human Exposure to Trace Metals

• Inhalation of air
• Ingestion of water
• Ingestion of food
• Ingestion of dust

Calculating Mass of Trace Metal Absorbed by the Body/Time

Mass of trace metal absorbed by the body/time = A_i = C_i U_i f_i

Where

i = air, water, food, or soil/dust

C_i = concentration of the trace metal in medium i

U_i = uptake rate of air, water, food, or soil/dust

f_i = fraction of trace metal absorbed by the bloodstream

What is the”Dos” and How is it Determined?

The total amount absorbed is known as the dose and it is defined as:

D total = (A total)(t)

Where

A total = the total absorption rate from all exposure routes

t = time of exposure

Representing the Response to a Dose

The response to a dose may be represented by a dose-response curve. Based on the available dose-response relationships, we attempt to establish a maximum safe level below which there are no effects, known as the threshold level.