FINAL ENGR 202

Question 1

Define or describe

a) Risk

b) CFC:

c) NOAEL threshold:

d) F.C.

Answer 1

a) Risk: The probability of a specific undesired consequence

b) CFC: Chlorofluorocarbons

c) NOAEL threshold: No Observable Adverse Effects Level

d) F.C.: Fecal Coliforms

Question 2

What are the three steps of life cycle analysis?

Answer 2

Inventory Analysis

Impact Analysis

Improvement Analysis

Question 3

Give two reasons why the life cycle analysis is not more widely used?

Answer 3

-Gathering the data is time consuming and expensive. This only gets worse as the LCA is morecomprehensive.

-There is no universally accepted methodology. The assumptions made might be subjective

Question 4

Name three things that can affect the carbon cycle

Answer 4

-Deforestation

-Burning of fossil fuels

-Cement production

Question 5

Two major contaminants of groundwater and their sources?

Answer 5

-Petroleum contaminants from Leaking Underground Storage Tanks (LUST)

-Nitrates, from agricultural fertilizers

Question 6

What is bad ozone and its source?

Answer 6

It is ozone present at the ground level and is the main component of smog. Created by chemicalreactions between oxides of nitrogen (NOx) and volatile organic compounds (VOC) from motorvehicles, industrial facilities in the presence of sunlight.

Question 7

What is eutrophication and what is its cause?

Answer 7

It is the ecosystem response to the addition of nitrates and phosphates (from fertilizers/sewage)to an aquatic ecosystem. This promotes excessive plant and algae growth, to the detriment ofother forms of aquatic life, leaving a body of water that is unable to support fish or other lifeforms and is also unsuitable for human uses. The cause is runoff from agricultural fields and thedumping of untreated sewage into bodies of water.

Question 8

5) Explain the difference between a response curve for carcinogenic and noncarcinogenic chemicals?

Answer 8

Carcinogenic chemicals typically assume a linear relationship with no threshold. Any doseabove zero results in some risk.

Non-carcinogenic chemicals exhibit a flat horizontal line until a certain threshold, above whichadverse effects are observed.

Question 9

Name three things that are affected by global warming?

Answer 9

Rise of Sea level, and the flooding of low-lying regions

-Changes in weather patterns (increased droughts, floods, severity of storms)

-The viability of plant and animal life attempting to cope with rapid changes.

Question 10

What is global warming potential (GWP)?

Answer 10

It is a measure devised to compare different emissions in terms of an equivalent mass of CO2,to determine its contribution to global warming in terms of its radiative forcing and atmosphericlifetime.

Question 11

)What are three uncertainties associated with risk assessment?

Answer 11

-Lack of information on source location(s). -Poorly known history of contaminant releases -Unknown variability in mass or concentration distributions of contaminants -Complexity in the chemical composition of contaminants

Question 12

Mercury

Answer 12

Mercury is a common contaminant and it bioaccumulates in the tissues of fish and other
organisms. Humans can then be affected through the consumption of fish, suffering damage to
the central nervous system and the brain.

Question 13

What is the hazard quotient?

Answer 13

The metric used in risk assessments to compare an actual dose of the chemical to the reference dose. It is defined as the ration of the average daily dose (ADD), divided by the reference dose(RfD)
HQ = ADD / RfD

Question 14

Why population growth and economic growth are important, and why are they not included in the environmental analysis

Answer 14

Population and economic growth are outside the scope of an engineer domain(engineers can not control these factors)
Population growth → important because its directly proportional to raw materials used
Economic growth → important because more affluence(wealth) increases consumption
They are key drivers of
environmental change.

Question 15

Advantages and disadvantages of battery powered cars?
Disadvantages:

Answer 15

Pros:
Consume less energy,
No direct pollutants,
does not consume fossil fuels (renewable)
● Cons:
Expensive initial cost,
limited driving range,
lack of fueling stations
Often very long to recharge.
Waste from batteries ­> indirect pollution by using electricity generated by polluting power plants.

Question 16

fuel cells

Answer 16

It is a gas-powered electrochemical battery that takes hydrogen and oxygen and mixes them to
produce electricity. The byproduct of this reaction is water. They’re very expensive.

Question 17

P=Po(1+r)^t

Answer 17

P= final population
Po = initial population
r= yearly rate of increase <1.00
t= time in years

Question 18

Te=(So(1-a))^1/4/sigma

Answer 18

Te= Temperature of the earth in degrees K *** subtract 273 to obtain C if needed
So= Solar input (342W)
a= albedo (every surface has a value, 0.31 for the earth on average
sigma= Stefan-Boltzmann constant 5.67x10e-8

Question 19

2 benefits of designing a product to fit into a life cycle

Answer 19

Minimizes adverse impacts of waste
Reduces use of natural resources to make new products

Question 20

What is a pathogen

Answer 20

-Microorganisms 4 main groups, virus bacteria protoza worm.
-Found in polluted water
-Human health risks: typhoid, cholera, diarrhea, gastrointestinal, skin diseases, respiratory problems.

Question 21

Define MCL for drinking water

Answer 21

Maximum contaminant level, 1mg/l is equivalent to one unit of contaminant per million units of water on a mass bias

Question 22

Drinking water standards

Answer 22

Total Coliform bacteria
Fecal coliform bacteria
Streptococci

Question 23

Difference between potency factor and chronic daily intake

Answer 23

Chronic daily intake is the average daily dose of a chemical over the lifetime of an individual
Potency factor represents the incremental lifetime cancer risk corresponding to a chronic daily intake of 1mg/kg of a chemical.

Question 24

Incremental lifetime cancer risk

Answer 24

Incremental lifetime cancer risk = CDI X PF

Question 25

Chronic daily intake (CDI):

Answer 25

an average daily dose of a chemical over the lifetime of an individual/ his body weight
Formula = average daily dose(mg/da)/body weight (kg)

Question 26

Uncertainties in assessing risk for noncarcinogenic

Answer 26

Reference dose: key parameter used in risk assessment to characterize the safe dose of a non-carcinogenic chemical.
Hazard quotient (HQ) : metric used in risk assessment to compare a reference dose of a chemical to an actual dose. Defined as ratio of average daily dose. (ADD) of a chemical divided by the reference dose.

Question 27

Why does mercury receive so much attention in scientific studies?

Answer 27

Can damage the brain and nervous system .
Mercury bioaccumulates in fish ad other organisms
Humans can be affected by the consumption of fish
Fatal at sufficiently high levels

Question 28

3 factors affecting co2

Answer 28

GDP per capita
Population growth
Energy intensity

Question 29

What is bioaccumulation

Answer 29

Bioaccumulation is the accumulation of substances such as pesticides and other organic chemicals in an organism. For Example mercury in fish

Question 30

Hazard quotient

Answer 30

Metric used in risk assessment to compare an actual dose of chemical to a reference dose.
Ratio of average daily dose (ADD) of a chemical divided by the reference dose.

Question 31

4 steps of risk assessment

Answer 31

Assessment of hazards
The development of dose-response relationships
Exposure assessment
Risk characterization

Question 32

3 key factors that influence environmental change

Answer 32

Housing and industrial development
Agriculture
Emissions of chemical substances to land air and water

Question 33

Describe the different types of coals:

Answer 33

Brown Coal also known as lignite is the lowest rank of coal in regards to energy content.
 Hard Coal also known as anthracite is not common and not typically used for power
generation.
 Soft Coal contains two types, they are the most common types of coal:
o Bituminous coal has higher energy content
o Subbituminous coal has lower energy content

Question 34

Describe the formation of Particulate Matter:

Answer 34

Particulate matter arises from solid incombustible materials such as iron, silicon, and other elements in the Earth’s Crust. Approximately 10% of coal burnt is particulate matter, ash

Question 35

How much more efficient is nuclear fuel?

Answer 35

Each Kilogram of processed nuclear fuel releases approximately 80,000 times more energy than an equal mass of fossil fuel.

Question 36

What are the 3 types of radiation emitted from nuclear processes?

Answer 36

 Alpha particles α
 Beta particles β
 Gamma radiation γ

Question 37

How many nuclear power plants exist in North America?

Answer 37

 100 in the United States
 5 in Canada

Question 38

What two incidents caused the end of the increase in nuclear power plants?

Answer 38

The 1979 Three Mile Island power station incident and Chernobyl caused the end of the increase in nuclear power plants.

Question 39

Describe the Environmental Impacts of Renewable Energy Sources:

Answer 39

Geothermal – Hydrogen Sulphide releases; local seismic effects; noise; land use.
 Biomass – Land requirements; ecological impacts of harvesting and transportation; loss
of species diversity; use of fertilizers; atmospheric emissions during harvesting and
conversion
 Solar – Land requirements for large-scale implementation; life cycle manufacturing and
disposal issues for PV solar cells.
 Wind – Land use requirements; visual impact; electromagnetic interference; birds.
 Ocean-based – Visual impacts; conflicts with shipping; water quality and sedimentation
pattern changes; ecosystem disruptions.

Question 40

What is the largest hydroelectric dam in the world?

Answer 40

The largest hydroelectric dam in the world is the three gorges dam on the Yangtze River in China.

Question 41

What are the different generator types and their principles of Operation?

Answer 41

 Electromechanical – Movement of a conductor in a direction perpendicular to a magnetic field.
 Electrochemical – Two dissimilar conductors immersed in an electrolyte
 Photovoltaic – Excitation of electrons in semiconductor materials by photons from the
sun (or another light source)
 Thermoelectric – Temperature difference between the junction and free ends of two
dissimilar metals
 Thermionic – Heat supplied to high-temperature conductor
 Piezoelectric – Pressure applied to certain crystalline materials

Question 42

How is Particulate Emissions Controlled?

Answer 42

An electrostatic precipitator is a device designed to capture fly ash emissions before they are released into the atmosphere.

Question 43

How are sulphur dioxide emissions controlled?

Answer 43

One way to control SO2 emissions is to switch to low-sulphur content coals. Another method is to install flue gas desulfurization systems that act as a scrubber for SO2 emissions

Question 44

How are Nitrogen Oxide Emissions controlled?

Answer 44

 The first method, known as combustion modification, alters the design of the burners and/or combustion chamber to affect the temperature, time, and other parameters that control NOx formation.
 The second method is to use a technology known as selective catalytic reduction. This technology uses a chemical catalyst to help selectively reduce the nitrogen oxides in the flue gas back to molecular nitrogen.
 A selective non-catalytic reduction employs the same basic chemistry as a SCR but without the aid of a catalyst.