Engr 202

Front 1

PNI:

Total amount of water estimate?

How much is fresh water?

Back 1

1386×10^15 m^3

and

35×10^15 m^3.

Front 2

Name two things necessary to know how much waste a body of water can tolerate.

Back 2

(1) the type of pollutants discharged, and

(2) how the pollutants affect water quality.

Front 3

Name two categories of water pollutant sources and two types of water pollutant sources for each category.

Name a couple of nasty water pollutants that can come from these sources.

Back 3

Point sources: (1) Domestic sewage, (2) Industrial wastes

• Non-point sources: (3) Agricultural runoff, (4) Urban runoff

Front 4

1. What happens when air comes into contact with water?

2. Does oxygen dissolve in water?

3. Does O2 react with water?

4. Name one of the most important factors of water quality.

5. What is the DO (dissolved oxygen) saturation value?

Back 4

1. • When air comes in contact with water, some of O2 enters the water.

2. • Yep , Most gases of air including oxygen dissolve in water.

•3. Nope, O2 does not react chemically with water.

• One of the most important factors of water qualityis the amount of dissolved oxygen (DO) presentedin water.

• Oxygen is soluble in water to a limited degree thatis called DO saturation value.

Front 5

What factors influence the Dissolved oxygen Saturation value? (3 things ish)

Back 5

The saturated value of dissolved oxygen (DO) in waterdepends upon the temperature of water, theatmospheric pressure and the water salinity. The latteris less effective.

extra:

For instance, saturated values of DO are:

12.8 mg/L at T = 5 oC and mean sea level (MSL)9.1 mg/L at T = 20 oC and mean sea level (MSL)11.4 mg/L at T = 5 oC and altitude of 1000 m aboveMSL

Front 6

PNI: 1. range of DO saturation values for water?

2. Minimum amount of DO needed for aquatic life?

3. What does the acronym OD represent (not talkin bout you drug habits)? What are the mains sources of OD material?

Back 6

1. The saturated value of dissolved oxygen (DO) in water falls between 6 to 15 mg/L

2. The minimum amount of DO needed for aquatic life is between 2 to 8 mg/L depending on the type of creature.

3. Anything that can be oxidized in water by using water DO is called oxygen-demanding (OD)material.

Organic wastes are the main source of oxygen-demanding materials in surface waters.

Front 7

1. What effects do OD materials have in water?

2. what are the consequences of those consequences (Consequinception)

PNI: 3. Name the besterds that dump OD mat. in water.

Back 7

1. Oxygen-demanding materials are oxidized in the receiving water body, reducing the amount of DO available .

2. Depletion of DO in water courses can threaten fish and other aquatic life.

3. Industrial wastewater of paper mills and foodprocessing plants contains a large amount of oxygen-demanding materials

Front 8

• The three methods to determine theamount of oxygen demand of awater/wastewater sample:

Back 8

- Theoretical Oxygen Demand (ThOD)

– Chemical Oxygen Demand (COD)

– Biochemical Oxygen Demand (BOD)

Front 9

Theoretical Oxygen Demand (ThOD) dafuk is dis? thel mi.

Back 9

The oxygen demand for oxidation of pure materials can be estimated from stoichiometry, assuming that all oxygen-demanding materials are completely oxidized.

This method may be used to calculate the amount of Oxygen Demand (OD) for carbonaceous organic matter and nitrogenous organic matter.

To use this method, the type and amount of organic matters must be known.

****Most waste waters are rarely pure materials.Therefore, it is not possible to calculate the OD of these waste waters by using stoichiometry. ******

Front 10

Chemical Oxygen Demand (COD) dafuc is dis? tel mi.

Back 10

• In contrast to the ThOD, the chemical oxygendemand (COD) is a measured quantity of oxygendemand that does not depend upon knowledgeof materials.

• In a COD test, a strong chemical oxidizing agentand a strong acid are added to the water sample;then, it is mixed and heated. The differencebetween the amounts of the oxidizing agent atthe beginning and the end of test is used tocalculate the COD.

Front 11

Biochemical Oxygen Demand (BOD) dafuch is dis? tel mi.

Back 11

the oxidation of materials are carried out by microorganisms.

The amount of oxygen required by microorganisms to biologically degrade the wastes is measured.

A test is run to measure the BOD. The sampled water is kept in a nonreactive glass bottle sealed.

The standard test is run at 20 oC in the dark for 5 days (BOD5).

It is possible to have an n-day BOD test.

The DO is measured everyday to create a curve.

The BOD is a common measure of the strength of organic pollution in water.

Front 12

1. Name Two essential nutrients to grow vegetation and other things that are not dead. Is there such a thing as too much of something \any problems?

2. Where do you find these nutrients extensively

3. What leads to eutrophication .... wtf is that even? What's it do?

4. What does eutrophic water support other than you and your family?

Back 12

1. Phosphorus and Nitrogen are two essential nutrients to grow vegetation and other living things. Problems arise when nutrient levels in water are excessively increased.

2. Nutrients are extensively found in fertilizers,phosphorus-based detergents, food processing wastes, etc.

3. Phosphorus and Nitrogen exceedingly enrich the nutrients in the surface water bodies, leading to eutrophication.

"excessive richness of nutrients in a lake or other body of water"

The more nutrients in water, the more vegetation and plant. Consequently more oxygen is demanded.

4. A eutrophic water course supports a growth of algae that crowd out other forms of aquatic life,putting fish and other creatures in danger.

Front 13

Thermal Pollution:

What happens when you increase the temperature of water other than you making tea

Back 13

• Oxygen’s solubility decreases with an increase in temperature.

• Chemical and biological reactions increase when water temperature increases.

• The solubility of certain chemical compounds,such as sodium chloride, increases with an increase in water temperature.

ie. • Temperature affects characteristics of water.

Front 14

Suspended Solids & Dissolved Solids (Salts) 1

1. Difference between the two types of solids in water?

2. Why is water sometimes saltier than you?

3. What does Ground surface water do when it sees some fiiiiiinnee solids?

Back 14

1. Dissolved solids are in solution (ie. homogeneous mix) whereas suspended solids are suspended in the water (ie. heterogeneous mix)

2. b/c Water passing through soil and rock media accumulates different types of dissolved solids(salts).

• Ground surface water flow may accumulatesome dissolved solids, but it mostly responsiblefor washing the fine soil particles such as siltsthat cannot be dissolved in water.

Front 15

Suspended Solids & Dissolved Solids (Salts) 2

1. How you seaparate the solids from water?

2. What you use to determine amount of suspended students i mean solids

Back 15

1. By heating water at 103oC, water evaporates and the solids remain (total solids).

2. To determine the amount of suspended solids in water, a Gooch crucible (Gooch filter) including a glass filter can be used.

- Dissolved solids pass through the filter with the aid of a vacuum

- Suspended solids are retained on the filter.

Then, the amount of dried suspended solids can be measured.

The difference between the total solids and suspended solids will be the dissolved solids.

Front 16

1. What does TDS stand for?

PNI: 2. What are the limits of TDS for fresh/mixed/salty water ?

PNI: 3. How's the TDS in Bikini Bottom (ie. in Sea water)

Back 16

1.Although these salts include several solids such as calcium, sodium, potassium, magnesium, etc.,the concentration of total dissolved solids (TDS)can be used to express the salinity of water.

2. TDS concentrations of 1500 and 5000 mg/L can be approximately considered as limits for fresh,brackish, and saline waters.

3.Sea water has a TDS concentration of more than30 000 mg/L.

Front 17

1. What are pathogens?

2. What they do to hoomans?

Back 17

1. Pathogens are disease-producing organisms that grow in the host (or water). Pathogens that are associated with water are viruses, bacteria,protozoa, and helminthes.

2. Pathogens in water can cause human illnesses.

In many countries, the presence of pathogens in water supplies is still an issue.

Front 18

1. Two important classes of toxic organic chemicals are ?

2. What do they each do?

Back 18

1.

– Pesticides and

– Volatile Organic Compounds (VOCs).

2.a) Pesticides, that cover a range of chemicals, kill undesirable organisms. They are used for agricultural and non-agricultural purposes.

2.b) Volatile Organic Compounds (VOCs) include chemicals that are solvents and used inindustrial processes. The “volatile” is used because these chemicals are presented in surface waters with very lowconcentrations (a few μg/L); but, in ground water their concentrations are increased to several hundreds or thousands μg/L.

Front 19

<-- note fancy VOC trends

PNI: There are five VOCs (Volatile Organic Compound) that are toxic:

Name them and describe their common use.

Back 19

1) Vinyl chloride or Chloroethylene (C2H3Cl) that is used in the production of polyvinylchloride (PVC) resins.

2) Tetrachloroethylene (C2Cl4) or Perchloroethylene (PCE) that is used in the production of chlorofluorocarbons. It is also used as a solvent and as a heat transfer medium.

3) Trichloroethylene (C2HCl3) that is a solvent. TCE is used to clean electronic parts, septic tanks, jet engines, etc.

4) 1,2-Dichloroethane (C2H4Cl2) that is used as metal degreasers in manufactures.

5) Carbon tetrachloride (CCl4) that is used in solvents, grain fumigants, fire extinguishers. It is very toxic if ingested.

Front 20

1. True/False? Human bodies and other living organisms requires very small amounts of some certain metals.

2. What filters these metals from our bodies?

3. Any metals that are toxic to even those filters?

4. How do these toxic metals enter water bodies?

Back 20

1. True however, too much of necessary metals in human bodies can be toxic.

2. Our kidneys can filter some toxic metals if theiramounts are very small.

3. Some toxic metals such as lead, mercury, and cadmium are toxic to kidneys.

• Toxic metals enter water bodies via effluents of mining areas, construction sites, and industrial units. Some metals may enter the waters from the atmosphere by deposition.

The toxic metals that can be found in the water bodies are: aluminum, arsenic, beryllium, bismuth, cadmium, chromium, cobalt, copper, iron, lead, manganese, mercury, molybdenum, nickel, selenium, strontium, thallium, tin, titanium, vanadium, and zinc.

Front 21

1. What makes water acidic?

2. What pH values indicate acids/base?

3. Minimum pH for the fishies to not be dead?

Back 21

Water is acidic if it contains a high concentration of hydrogen ions in solution. Negative logarithmof hydrogen ions concentration is known as pH.

2.

- Water with pH lower than 7 is acidic.

- Water with pH higher than 7 is alkaline or basic.

3. To be survived, fish must live in waters with pHs not lower than 5 (5.5 for some).

Some sources include:

Some industrial processes as well as mining operations generate acidic effluents.

Another source of acidic waters is atmosphere(acid rain)

Front 22

Name les trois types of water quality standards:

Back 22

– Drinking water standards

– Surface water quality standards, and

– Effluent standards.

Front 23

1. What act set the Effluent Standards used to control the flow of pollutants intonatural water bodies such as streams, lakes,oceans, and groundwater?

PNI: 2. What are its effects?

3. Are Pollutants such as total suspended solids and BOD are listed by the EPA?.

PNI: 4. From who are all point source effluents releasing wastewater to natural water bodies are required to obtain a permit from?

PNI: 5. From who must all point source discharges to sewer systems obtain permit from ?

Back 23

1. In the United States, the Clean Water Act (CWA)

2. Based on the Clean Water Act, the best available control technology is required at any new plant or facility discharging any of the 126 priority toxic pollutants identified by the US Environmental Protection Agency (EPA)† .

3. No, Pollutants such as total suspended solids and BOD are not listed by the EPA.

4. National Pollution DischargeElimination System (NPDES).

5. The municipaltreatment plants receiving the waste.

Nowadays, in the U.S.A., the major problemsthat are required more attention and regulationsare nonpoint sources of water pollutions.

Front 24

What is a hydrologic cycle?

Back 24

A hydrologic cycle is a set of pathways to show how watermoves and is distributed on the earth.

Front 25

How is the air composed?

What qualifies as polluted air?

Back 25

Pure air consists nitrogen (78%), oxygen (21%),and some other gases – all together 1% (tracegases).

• If the concentration of any gas composing the airis changed (mostly increased), the air is polluted.

Front 26

Air pollutants can be categorized into three groups:

Back 26

– Pollutants that affect the indoor air quality.

– Pollutants that are responsible for the air qualityof a municipal area (outdoor air quality).

– Those that cause global issues such as ozone layerdepletion and global warming.

Front 27

One approach to classification of air pollutants is that of primary and secondary pollutants. State the differences

Back 27

The primary pollutants are emitted to the atmosphere, whereas the secondary pollutantsare produced in atmosphere by chemicalreactions.

Front 28

EPA (Environmental Protection Agency) of the United States has established the National Ambient Air Quality Standards (NAAQS) to control the air pollution in the U.S. For what six pollutants does the NAAQS have criteria set ?

Back 28

– Carbon Monoxide (CO),

– Lead (Pb),

– Nitrogen Dioxide (NO2),

– Ozone (O3),

– Particulate matter (PM10 and PM2.5), and

– Sulfur Dioxide (SO2).

Front 29

1. Define Particulate Matter (PM)

2. What three things do air quality standards control the levels of ?

Back 29

1. Any solid or liquid particle suspended in air iscalled particulate matter (smaller than 500 µm).

2a). PM10 (particles smaller than 10 µm indiameter),

2b). PM2.5 (particles smaller than 2.5 µm in diameter), and/or

3c) Total suspended particulates.

Front 30

1. What is special about Particular matter smaller than 10 µm?

2. Do PM have other effects?

3. What type of PM are of greatest concern?

Back 30

1. Particular matter smaller than 10 µm can penetrate into the lungs.

2. PM can also reduce the visibility and damage theproperties.

3. Toxic PM such as pesticide residues and heavy metals are of greater concern.

Front 31

note the cool PM10 trends

Back 31

note the lame PM2.5 trends

Front 32

1. Where is Carbon dioxide (CO2 ) emitted from?

2. When is carbon monoxide (CO) that is, the most abundant air pollution, produced?

3. Complete combustion occurs when the what are kept sufficiently high?

Back 32

1. From completecombustion of carbon-containing materials.

2. Produced when fossil fuels or othercarbon-containing substances are combustedincompletely (under less than ideal conditions).

3. When the following are kept high:

oxygen supply,

combustion temperature,

gas residence time inhigh temperature, and combustion chamberturbulence.

Front 33

<-- Note riveting trend in CO emissions.

1. How much carbon monoxide do Power plants emit?

2. True/False? Carbon monoxide is very poisonous

3. Name four main gases responsible for the greenhouse effect and global warming.

Back 33

1. Power plants Emit less than 1% of carbonmonoxide because they burn fossil fuelsproperly.

2. Yep, true af

3.

Carbon dioxide (CO2 )

methane (CH4 ),

nitrous oxide (N2O),

fluorinated gases

is responsible for the greenhouse effect and global warming.

Front 34

<-- Note peculiar trend in SO2 emissions.

1. Where is Sulfur dioxide (SO2 ) generally emitted from?

2. What happens when oil and coal that contain significant amounts of sulfur are burned

3. What does SO2 do in life?

4. How would you describe SO3 if you were introducing it to a friend?

Back 34

Sulfur Oxides (SO3 & SO2)

1. Fromthe fossil fuel combustion, mostly from electricutility power plants.

2. When oil and coal that contain significant amounts of sulfur are burned, the sulfur dioxide(SO2) and small amounts of sulfur trioxide (SO3)are released.

3. Sulfur dioxide damages vegetation, property,and human health.

4. Sulfur trioxide is highly corrosive and damagesproperties.

extra: As non-combustion sources, cement manufactures, petroleum refining, and copper smelting are other sources of sulfur oxides emission

Front 35

What compounds are responsible for acid rain?

Back 35

Sulfur oxides as well as nitrogen oxides are responsible for the acid rain.

Front 36

1. Where are Nitrogen oxides emitted from?

2. Is it toxic to humans or to you?

Back 36

1. fuelcombustion, but compared with carbon monoxide (CO) andsulfur dioxide (SO2), the amount of nitrogendioxide (NO2) emitted from fuel combustion isnot high.

2. Nitrogen dioxide (NO2) is toxic for human healthonly in very high concentrations.

Front 37

<-- Note inspiring trend in NO2 emissions.

1. True/False? Nitrogen oxides are the major components information of ground-level ozone that causesphotochemical smog.

2. A Nitrogen dioxide molecule asks you how babies (ie. NO2) are made, how do you respond?

Back 37

1. true, not like i would write that ever

2. When the nitric oxide (NO) is emitted to the atmosphere, it gradually reacts with O and turns to NO2.

Front 38

<-- Note Demise of Lead emissions.

1. What does everyone know about Lead and its effects on ppl.

PNI: 2. Just how stoopidh did carmakers get with lead?

PNI: 3. You need to renovate the kitchen, what type of paint and plumbing do you get?

4. Sources of Lead nowadays other than Flint water?

Back 38

1. Lead is extremely dangerous to human health.

2. Major amount of lead was previously emittedfrom automobiles used leaded gasoline. Nowadays, leaded gasoline is not used in the developed countries.

3. Lead! lead is found in the paints used inbuildings as well as water pipes.

4. Lead smelting andmanufacturing processes are sources of leademission.

Front 39

1. What's acid rain?

2. pH of normal rain?

3. pH of rain on my house?

4. How bad does it get?

5. How does it feel to sit under acid rain when you are a fish?

Back 39

1. Acid rain refers to any kind of precipitationwhose acidity is more than normal.

2. Normal rain has a pH of about 5.6 owing of CO2.

3. Acid rains have a pH between 4 to 5 in theeastern states of the US and southern regions ofOntario and Quebec.

4. Acid rain having pH of 2 also occurs in theWorld.

5. You die. In different parts of the world, acid rain hasaffected water bodies specially lakes in whichfish and other aquatic creatures no longer exist.

Front 40

<-- cool recipe to try at home

Back 40

What acid rain is made of:

SO3 + H2O → H2SO4sulfuric acid

2NO2 + O3 + H2O → 2HNO3 + O2 nitric acid

Front 41

Do you know what smog is? ie. Photochemical smog

Back 41

Emission of air pollutants to the atmosphere occurseveryday that create a cloud over an urbanarea, specially a large city, that is calledphotochemical smog or simply smog.

Front 42

When does Photochemical smog happen?

Back 42

When

– nitrogen oxides (NO2 and NO),

– VOCs, mostlyhydrocarbons,

– carbon monoxide (CO), and

– sunlight

come together,

they can create a number ofsecondary pollutants known asphotochemical oxidants.

Front 43

Who's the strongest photochemical oxidant of them all ???

Back 43

Among all photochemical oxidants, ozone (O3) isthe strongest oxidizing agent.

Front 44

Where do you find Ozone?

Back 44

Ozone presents at two different levels:

(1) high-levelor stratospheric ozone (10-15 km),

(2)ground-level or tropospheric ozone (1km).

Front 45

In what ways is high-level Ozone the hero the earth needs?

Back 45

The high-level ozone (ozone layer) acts as anultraviolet radiation shield and protects theearth. The upper atmospheric ozone layer is also calledprotective ozone layer or simply ozone layer.

Front 46

Why is Ground-level ozone so despised?

Back 46

Because Ground-level ozone, as a photochemical oxidant,is called “bad’’ ozone.

Front 47

Where does Ozone come from? What are its roots? Does it miss its home?

Also, what happens when Ozone meets Nitric Oxide?

Back 47

• Ozone (ground-level ozone) is formed as follow:

NO2 + Light → NO + O

O + O2 → O3(ozone)

• Ozone then reacts with nitric oxide (NO) andcreates nitrogen dioxide (NO2) again.

Front 48

1. Are concentrations of gases in smog fixed?

2. Why are the concentrations affected?

Back 48

1. No, the formation of smog is a dynamic process.

The concentrations of NO2, NO, HC, O3, andother pollutants vary during the day.

2. The pollutant concentrations in smog changeduring day because of changes in the humanactivities as well as the sunlight.

Front 49

Global warming describes the increase ofaverage temperature of the Earth over a periodof time.

PNI: some Obvious Climate Change stuff on the otherside

Back 49

Climate change is not synonymous to weatherchange.

• Climate change is a change in the typical oraverage weather of a city, a region, or the Earth.

• This could be , for example, a change in theaverage annual precipitation or a change in theaverage temperature of a region for a givenseason or any other period.

• Climate change could be also a change in Earth'saverage temperature, Earth's typicalprecipitation patterns, etc.

Front 50

PNI: facts about solar radiation and stuff

note: earth receives small length EM waves and emits long length EM waves.

Back 50

The earth receives energy from sun by radiation;the solar radiations are short-lengthelectromagnetic waves.

• A small but important range of solar radiationscalled solar ultraviolet radiations (with mostlywavelengths of 0.1-1 μm) are absorbed by ozone(O3) and other trace gases at the altitude of10~20 km.

On the other hand, the earth surface emitsenergy by radiation back to the atmosphere; theearth radiations are long-length electromagneticwaves (with wavelengths of greater than 1 μm).

• This good ozone acts as an shield and protectsthe earth from the solar ultraviolet radiation.

Front 51

What are Greenhouse Gases?

Back 51

The combination of radiatively activegasses in atmosphere that let pass the solar short-waveradiations but absorb the long-waveradiations emitted from the earth. Greenhouse gases trap heat in theatmosphere causing the climate change

The term “greenhouse” is adopted from theconcept of a conventional glass greenhouse inwhich the glass traps some radiations leaving thegreenhouse.

Front 52

PNI: The most important radiatively active gases thatnaturally exist in the atmosphere are:

Back 52

Water vapor (H2O) 55%

Carbon dioxide (CO2) 39%

Nitrous oxide (N2O) 2%

Methane (CH4) 2%

Ozone (O3) 2%

Front 53

1. What would the average temperature of its surface be If the earth were to not have the greenhouse effect?

2. What is Earth's actual temperature with this effect?

Back 53

1. the average temperature of its surface would be−19oC.

2. The average temperature of the earth surface isactually around 15oC;

i.e. the greenhouse effectincreases the earth surface temperature 34oC.

PNI: not-so-fun facts:

When the concentrations of greenhouse gasesare increased, due to human activities, thegreenhouse effect will be enhanced.

Carbon dioxide (CO2) from combustion of fossilfuels and deforestation is the first concern.

Nowadays, other greenhouse gases speciallynitrous oxide (N2O) and methane (CH4) are alsobecoming as important as carbon dioxideaffecting the climate change.

Front 54

Human activities add some othergases (fluorinated gases).

Back 54

<-- look at this sad trend of CO2

Front 55

note how transportation and electricity are the largest sources of C02

Back 55

idk just look

Front 56

PNI: How many Fluorinated gases can you name?

Back 56

Fluorinated gases are:

- Hydrofluorocarbons (HFCs),

- Perfluorocarbons (PFCs),

- Sulfur hexafluoride (SF6),

- Chlorofluorocarbons (CFCs), and - Hydrochlorofluorocarbons (HCFCs).

• HFCs have been developed as a replacement forCFCs and HCFCs.

Front 57

What is GWP and what affect its value?

Back 57

The global warming potential (GWP) is definedto compare the emissions of differentgreenhouse gases

The two most significant characteristics of a greenhouse gas in terms of climate impact are:

(1) How well the gas absorbs energy (trappingthe heat)

(2) how long the gas stays in theatmosphere

Front 58

1.What is greenhouse gas has the smallest GWP?

2. How does this affect the measurement of GWP?

Back 58

1. CO2. One gram of carbon dioxide (CO2) has lessinfluence on the global warming than one gramof any other greenhouse gas.

2.The total energy that a greenhouse gas absorbsover 100 years, compared to carbon dioxide, ismeasured as the GWP of that gas.Therefore, the GWP of carbon dioxide is unity.

Front 59

can you solve?

Back 59

Front 60

1. What are and what do CFCs do?

2. What are they made of?

3. Are they natural?

PNI: 4. What are they used in?

Back 60

1. Chlorofluorocarbons (CFCs) cause the depletionof the protective ozone layer.

2. These molecules contain chlorine (Cl), fluorine(F), and carbon (C).

3. Similar to other fluorinated gases, CFCs do notexist naturally in the atmosphere.

4. CFCs are used in solvents, refrigerators, airconditioners, foaming agents, and aerosols.

Front 61

PNI: 1. What are two major types of CFCs?

2. Why are they so important?

3. What happens to them in upper layers of the atmosphere?

Back 61

1. Two major types of CFCs are:

– trichlorofluorocarbons (CFCl3 or CF-11), and– dichlorodifluoromethane (CF2Cl2 or CF-12).

2. These two types of CFCs cannot be washed out inatmosphere because they are not water soluble.Consequently, they are not easily destroyed.

3. When they drift into the upper layers, they arehit by short-wave solar radiation.

Front 62

How does Ozone protect us from the light?

Back 62

1. Ozone (O3) is created when oxygen (O2) reacts withsunlight:

O2 + Light → O + O

O + O2 → O3 formation of ozone

2. Ozone is again destroyed when is hit by light:

O3 + light → O2 + O

destruction of ozone(it acts as a shield)

Front 63

PNI: Just note:

CFCs + Ozone (O3), as a harmful reaction:

either CF2Cl2 + Light → CF2Cl + Cl

or CFCl3 + Light → CFCl2 + Cl

then, Cl + O3 → ClO + O2(I)

and then, ClO + O → Cl + O2(II)

• Reactions I and II occur thousands of timesduring around one month as a loop and destroyapproximately 100 000 molecules of ozone upthere.

Back 63

After one month, Cl reacts with methane or otherchemical compounds:

Cl + CH4 → HCl + CH3

• Then, HCl comes down to the lower layers wherethey are washed out by rain. This process alsotakes around one month.

Front 64

PNI: just note:

In the 1930s, CFCs were invented.

• In the 1970s, CFCs were banned by the USEPAin nonessential aerosols.

• In the 1980s, the ozone hole was discovered inthe South Pole.

• Ozone layer in the South Pole gets thin duringAugust and thick between September andNovember.

Back 64

In 1987, the Montreal Protocol was signed bymore than 30 countries.

• The Montreal Protocol is an agreement designedto phase out the CFCs, HCFCs, halocarbons, andother substances that are responsible for ozonelayer depletion.

• About 95% and 60% of ozone layer in the SouthPole was destroyed, respectively, in the late1970s and in 1994.

Front 65

Oil (petroleum) , natural gas, and coal are fossilfuels. State what percentage of the world's energy came from such fossil fuels.

Back 65

• 86% of the world’s energy was produced by fossil fuels.

Sources supplying the world’s energy in 2006:

– 35.8% Petroleum and other liquids

– 26.7% Coal

– 23.5% Natural gas

– 6.4% Nuclear

– 6.5% Hydropower

– 1% Geothermal, wind, solar, wood, …

Front 66

Just some graph PNI

mostly consumed fossil fuel energy

Back 66

PNI some graph

Venezuela, Saudi, Canada = top 3 oil producers

Front 67

PNI some graph

Russia, Iran, Quatar top three natural gas producers

Back 67

China, US, India = top three coal consumers

Front 68

1. What are fossil fuels formed from?

2. What do they consist of in terms of elements?

3. What impurities are commonly found in them?

4. What happens when you burn fossil fuels?

Back 68

1. Fossil fuels are formed from the decomposition ofdead organisms such as animals and plants buried ingeological formation.

2. They mainly consist of carbon (C) and hydrogen (H).

3. Sulfur, oxygen, mercury, and ash are also impuritiesof fossil fuels.

4. When a fossil fuel is burned, the atomic bondsbetween C and H are broken, and consequentlychemical energy is released.

Front 69

PNI: Alkane is a hydrocarbon (HC) that consists ofhydrogen and carbon having single bonds (CnH2n+2)

Back 69

Mostly Carbon and Hydrogen

Front 70

Name a few Environmental Impact of Fossil Fuels..

Back 70

• Thermal pollution

• Particulates

• Carbon Monoxide (CO)

• Carbon Dioxide (CO2)

• Nitrogen Oxides (NOx)

• Hydrocarbons (HC)

• Sulfur Dioxide (SO2)

Front 71

How do fossil fuels harm water bodies through thermal pollution?

Back 71

In most cases, water taken from a lake or river isused to cool the engine; then, the warm water isreturned to the water body.

• Increasing the temperature of a water body is harmful

Front 72

1. How do fossil fuels result in particulates?

2. How do coal fired sites reduce particulate pollution?

3. How do Electrostatic Precipitators work?

Back 72

1. Particulates appear as smoke during combustionof coal. Particulates (ashes) are the result of incombustiblematerials such as iron and silicon in coal (10%).

2. Most coal-fired sites utilize efficient systems suchas baghouses (mechanical filters) or electrostaticprecipitators for reducing particulate pollution.

• Electrostatic precipitators use electrostaticallycharged plates to collect the particles.

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PNI: Relate CO2, CO, NOx, HC, SO2 to Fossil fuels

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• Carbon dioxide (CO2 ) is the result of complete combustion of all kinds of fossil fuels.

• Carbon monoxide (CO) is the result of incomplete combustion.

• Hydrocarbons (HC) are released during incomplete combustion of fossil fuels.

• Nitrogen oxides (NOx ) results from the combustion of fossil fuels when temperature is higher than 1100oC.

• Sulfur dioxide (SO2 ) results from the combustion of sulfur-containing fuels

EXTRA fun facts:

Carbon dioxide (CO2) is the major pollutantresponsible for greenhouse effect enhancementand global warming.

• Carbon monoxide (CO) is poisonous.

• Hydrocarbons (HC) emissions are responsiblefor formation of photochemical smog.

• Sulfur dioxides (SO2) are responsible for acidrain.

• Nitrogen oxides (NOx) are responsible for bothacid rain and formation of photochemical smog.

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When does incomplete Combustion occur?

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• As mentioned before, an incomplete combustionoccurs when:

– There is insufficient air (oxygen) to combust,

– The temperature is not high enough duringcombustion,

– There is not enough gas residence time in hightemperature, and

– There is insufficient turbulence in the combustionchamber

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PNI: Ways of reducing emissions, state two

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• By modifying the combustion (its burner and/orchamber), the emissions of carbon monoxide(CO), hydrocarbon (HC), and nitrogen oxide(NOx) can be reduced.

• There are advanced technologies that can be usedto control the emissions of sulfur dioxide (SO2)and nitrogen oxide (NOx).

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Explain CO2 Sequestration

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• Because combustion of fossil fuels emits CO2, areduction in fossil fuel use will cause areduction in carbon dioxide emission.

• CO2can be pumped into depleted oil wells andnatural gas wells.

• It may be disposed in ocean as gaseous CO2

• It could be liquefied and pumped into ocean.

• It may be released into the ocean as a solid compound.