Unit C Environmental Chemistry Read pg. 180-190. 1.1 Chemicals in the Environment

Unit CEnvironmenta

l Chemistry

Read pg. 180-190

1.1 1.1 Chemicals in Chemicals in

the the EnvironmentEnvironment

Environmental chemistry studies the Environmental chemistry studies the processes and activities that change processes and activities that change chemicals in the natural environmentchemicals in the natural environment

Our environment may yet offer many cures Our environment may yet offer many cures for disease and cancerfor disease and cancer

1.1 Chemicals in the EnvironmentJ. Dulku – Science 9

The EnvironmentThe Environment Slide 1 of 7Slide 1 of 7

Chemicals released into the atmosphere Chemicals released into the atmosphere include: water vapour, carbon dioxide, include: water vapour, carbon dioxide, sulphur dioxide, carbon monoxide, and ashsulphur dioxide, carbon monoxide, and ash

Natural processes include forest fires, Natural processes include forest fires, volcanoes, and the nitrogen cyclevolcanoes, and the nitrogen cycle

Nitrogen Cycle

Nitrogen Cycle

decomposers free nitrogen (N2)

nitrogen fixing bacteria

simple nitrogen compoundsplants

complex nitrogen compounds

animals

waste compounds

Plants need nitrogen for growth & Plants need nitrogen for growth & reproduction, but they can’t use “free reproduction, but they can’t use “free nitrogen” (Nnitrogen” (N22 gas) gas)

During During nitrogen fixationnitrogen fixation, bacteria , bacteria combine free nitrogen with other elementscombine free nitrogen with other elements

Plants then consume the fixed nitrogenPlants then consume the fixed nitrogen Animals eat plants, and make complex Animals eat plants, and make complex

nitrogen compoundsnitrogen compounds Microorganisms break nitrogen compounds Microorganisms break nitrogen compounds

down into free nitrogen, beginning the cycle down into free nitrogen, beginning the cycle againagain 1.1 Chemicals in the EnvironmentJ. Dulku – Science

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The Nitrogen CycleThe Nitrogen Cycle Slide 2 of 7Slide 2 of 7

Human activities can also change Human activities can also change substances in the environmentsubstances in the environment

PollutionPollution is any change in an environment, is any change in an environment, to produce conditions harmful to living to produce conditions harmful to living thingsthings

FertilizersFertilizers are substances that enrich soil are substances that enrich soil so that plants grow betterso that plants grow better

Too much fertilizer can harm a plant, or Too much fertilizer can harm a plant, or leach into water systems and harm other leach into water systems and harm other organismsorganisms


FertilizersFertilizers Slide 3 of 7Slide 3 of 7

PesticidesPesticides are chemicals designed to kill are chemicals designed to kill pests: herbicides, insecticides or fungicidespests: herbicides, insecticides or fungicides

PestsPests are organisms that can harm are organisms that can harm humans, plants or structureshumans, plants or structures

Pesticides that are incorrectly applied can Pesticides that are incorrectly applied can stay in the environment too long, causing stay in the environment too long, causing damagedamagee.g.e.g. DDT kills mosquitoes but takes 2-15 DDT kills mosquitoes but takes 2-15 years to years to break downbreak down


PesticidesPesticides Slide 4 of 7Slide 4 of 7

When we get rid of garbage, we can When we get rid of garbage, we can introduce chemicals into the environmentintroduce chemicals into the environment

Some waste is incinerated at high Some waste is incinerated at high temperatures, which can cause pollutiontemperatures, which can cause pollution

Other waste is reused or recycledOther waste is reused or recycled Remaining waste is put into landfill sites, Remaining waste is put into landfill sites,

and buried to biodegrade (which can be and buried to biodegrade (which can be slow!!)slow!!)

Sanitary landfills use compacted clay and Sanitary landfills use compacted clay and plastic liners to isolate hazardous chemicalsplastic liners to isolate hazardous chemicals


Solid WasteSolid Waste Slide 5 of 7Slide 5 of 7

SewageSewage is wastewater which contains is wastewater which contains dissolved and undissolved substancesdissolved and undissolved substances

Septic tanksSeptic tanks use bacteria to break down use bacteria to break down organic molecules in wastewaterorganic molecules in wastewater

Sewage treatment plantsSewage treatment plants remove harmful remove harmful substances from wastewatersubstances from wastewater

EffluentEffluent is treated wastewater that is is treated wastewater that is released into streams and lakesreleased into streams and lakes

Storm sewersStorm sewers are large pipes that take are large pipes that take rainwater directly to rivers and lakesrainwater directly to rivers and lakes


SewageSewage Slide 6 of 7Slide 6 of 7

Fossil fuelsFossil fuels are combustible substances are combustible substances made from dead plants and animalsmade from dead plants and animalse.g. coal, oil and natural gase.g. coal, oil and natural gas

Fossil fuels need oxygen to combust!Fossil fuels need oxygen to combust! The products are always carbon dioxide and The products are always carbon dioxide and

water, which are both greenhouse gaseswater, which are both greenhouse gases Natural gas is composed of fossil fuel gasesNatural gas is composed of fossil fuel gases When it contains deadly hydrogen sulphide, When it contains deadly hydrogen sulphide,

it is called it is called “sour” gas“sour” gas1.1 Chemicals in the EnvironmentJ. Dulku – Science

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Fossil FuelsFossil Fuels Last SlideLast Slide

1.1.22 Acids and Acids and

BasesBasesRead pg. 191-195

Acids and bases are compounds that will Acids and bases are compounds that will dissolve in water to form acidic or basic dissolve in water to form acidic or basic solutionssolutions

An An acidacid forms a solution with a pH of less forms a solution with a pH of less than 7than 7

A A basebase forms a solution with a pH greater forms a solution with a pH greater than 7than 7

A A neutralneutral solution has a pH equal to 7 solution has a pH equal to 7 pHpH is a measure of how many hydrogen is a measure of how many hydrogen

ions (Hions (H++) there are in solution) there are in solution Exact pH is measured using a pH meter, but Exact pH is measured using a pH meter, but

pH strips can give pH to the nearest whole pH strips can give pH to the nearest whole numbernumber

1.2 Acids and BasesJ. Dulku – Science 9

Acids vs. BasesAcids vs. Bases Slide 1 of 5Slide 1 of 5

Blue litmus paper Blue litmus paper turns Red in an turns Red in an ACIDACID


Litmus testLitmus test Slide 2 of 5Slide 2 of 5

Red litmus paper Red litmus paper turns Blue in a turns Blue in a BASEBASE If you forget which is which…remember If you forget which is which…remember

your your BBluelueBBase!ase!

pH scale tells us the HpH scale tells us the H++ ion ion concentration of Hconcentration of H++ ions in ions in solutionsolution

pH = 0 to 0.5 is a strong pH = 0 to 0.5 is a strong acidacide.g. He.g. H22SOSO44, HF, HF

pH = 14 is a strong basepH = 14 is a strong basee.g. liquid drain cleanere.g. liquid drain cleaner

pH = 7 is neutralpH = 7 is neutrale.g. pure ion-free watere.g. pure ion-free water


pHpH Slide 3 of 5Slide 3 of 5

We excrete hydrochloric acid to digest our We excrete hydrochloric acid to digest our foodfood

Antacids like Pepto or Alka-Seltzer are Antacids like Pepto or Alka-Seltzer are bases that react with leftover acid in our bases that react with leftover acid in our stomachsstomachs

When an acid neutralizes a base (or vice When an acid neutralizes a base (or vice versa), it is an acid-base versa), it is an acid-base neutralizationneutralization reactionreaction

Water and salt are produced during an acid-Water and salt are produced during an acid-base reactionbase reaction

A solution is considered neutral if pH = 7A solution is considered neutral if pH = 71.2 Acids and BasesJ. Dulku – Science 9

NeutralizationNeutralization Slide 4 of 5Slide 4 of 5

Industry produces SOIndustry produces SO22, NO, NOxx and CO and CO22 gases gases When these gases combine with water in When these gases combine with water in

the atmosphere, the atmosphere, acid rainacid rain may form may form pH of acid rain could be as low as 3 pH of acid rain could be as low as 3

(corrosive)(corrosive) Acid rain can kill organisms on land or in Acid rain can kill organisms on land or in

water, and destroys man-made structureswater, and destroys man-made structures Calcium hydroxide is used to neutralize Calcium hydroxide is used to neutralize

sulphuric acid in lakes, to form calcium sulphuric acid in lakes, to form calcium sulphate and watersulphate and water


Acid RainAcid Rain Last SlideLast Slide

1.1.33 Common Common

Substances Substances Essential to Essential to

Living ThingsLiving Things

Read pg. 196-203

Organic compoundsOrganic compounds are complex are complex molecules of carbon, hydrogen, oxygen and molecules of carbon, hydrogen, oxygen and nitrogennitrogene.g. sugar, paraffin wax, methane, ethanole.g. sugar, paraffin wax, methane, ethanol

Inorganic compoundsInorganic compounds are substances are are substances are compounds that do not contain carboncompounds that do not contain carbone.g. ammonia, baking soda, quartze.g. ammonia, baking soda, quartz

Carbon dioxide is Carbon dioxide is notnot an organic compound! an organic compound!

1.3 Common Substances Essential to Living ThingsJ. Dulku – Science 9

Organic & Organic & InorganicInorganic

Slide 1 of 7Slide 1 of 7

NutrientsNutrients are elements or compounds are elements or compounds needed by organisms for growth, repair and needed by organisms for growth, repair and reproductionreproduction

MacronutrientsMacronutrients are the 9 elements are the 9 elements needed in large amounts by organismsneeded in large amounts by organismsi.e. C, H, O, N, P, K, Mg, Ca and Si.e. C, H, O, N, P, K, Mg, Ca and S

MicronutrientsMicronutrients are elements that are are elements that are needed in trace (very small) amounts by needed in trace (very small) amounts by organismsorganismse.g. seleniume.g. selenium


Macro & MicroMacro & Micro Slide 2 of 7Slide 2 of 7

Sometimes too much of one nutrient can Sometimes too much of one nutrient can interfere with the absorption of other interfere with the absorption of other nutrientsnutrientse.g. K can interfere with Mg in farmers’ e.g. K can interfere with Mg in farmers’ cropscrops

The The optimum amountoptimum amount is the amount of is the amount of nutrient that provides an organism with the nutrient that provides an organism with the best healthbest healthe.g. too much selenium is toxic for animalse.g. too much selenium is toxic for animalse.g. too little selenium causes health e.g. too little selenium causes health problemsproblems

Optimum amount of selenium is 70 µg per Optimum amount of selenium is 70 µg per dayday


Nutrient LevelsNutrient Levels Slide 3 of 7Slide 3 of 7

CarbohydratesCarbohydrates are organic molecules of C, are organic molecules of C, H and O, that can be broken down into H and O, that can be broken down into simple sugarssimple sugars

Found in foods like pasta, rice, potatoes, Found in foods like pasta, rice, potatoes, bread and fruitbread and fruit

Sugars (e.g. glucose) can be assembled Sugars (e.g. glucose) can be assembled together to make larger, more complex together to make larger, more complex molecules like starch, cellulose or glycogenmolecules like starch, cellulose or glycogen

Carbohydrates are an energy source if used Carbohydrates are an energy source if used rapidly, but turn into fats if not used right rapidly, but turn into fats if not used right awayaway 1.3 Common Substances Essential to Living ThingsJ. Dulku – Science

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CarbohydratesCarbohydrates Slide 4 of 7Slide 4 of 7

LipidsLipids are organic compounds of C, H and are organic compounds of C, H and O, arranged into chains of fatty acidsO, arranged into chains of fatty acidse.g. fat, cooking oil, lard, waxe.g. fat, cooking oil, lard, wax

Both animals and plants make lipidsBoth animals and plants make lipids Found in nuts, seeds, soybeans and animal Found in nuts, seeds, soybeans and animal

fatfat


LipidsLipids Slide 5 of 7Slide 5 of 7

Amino acidsAmino acids are small organic molecules are small organic molecules made of C, H, N and Omade of C, H, N and O

A A proteinprotein is an organic compound made of is an organic compound made of chains of amino acidschains of amino acids

Used by organisms for growth, repair and Used by organisms for growth, repair and energyenergy

Found in meat, fish, eggs, dairy products, Found in meat, fish, eggs, dairy products, tofutofu

Proteins are also used to make enzymes, Proteins are also used to make enzymes, which are biological catalystswhich are biological catalysts


Amino Acids & Amino Acids & ProteinProtein


Nucleic acidsNucleic acids are molecules of ribose are molecules of ribose sugars, phosphates, and molecules of C, H, sugars, phosphates, and molecules of C, H, N and ON and O

The most complicated of organic moleculesThe most complicated of organic molecules Nucleic acids are the building material of Nucleic acids are the building material of

DNA and RNADNA and RNA Nucleic acids are found in all cellsNucleic acids are found in all cells


Nucleic AcidsNucleic Acids Last SlideLast Slide

1.4 1.4 How Organisms How Organisms Take in Take in

SubstancesSubstancesRead pg. 204-209

1.4 How Organisms Take in SubstancesJ. Dulku – Science 9

DiffusionDiffusion Slide 1 of 6Slide 1 of 6

Three ways for plants to get water and Three ways for plants to get water and nutrients: diffusion, osmosis and active nutrients: diffusion, osmosis and active transporttransport

DiffusionDiffusion is the is the movement of movement of

particles from an particles from an area of high area of high

concentration to an concentration to an area of low area of low

concentrationconcentratione.g. food colouring in e.g. food colouring in

waterwater

HH22OO HH22OOHH22OO

HH22OO HH22OO HH22OO

HH22OOHH22OO

HH22OO

HH22OO

HH22OO

HH22OO HH22OO

HH22OO1.4 How Organisms Take in SubstancesJ. Dulku – Science

9

OsmosisOsmosis Slide 2 of 6Slide 2 of 6

OsmosisOsmosis is the movement is the movement of water molecules (Hof water molecules (H22O) O) from the soil into a plant’s from the soil into a plant’s rootsroots

It is diffusion of water It is diffusion of water because of movement because of movement from high concentration to from high concentration to low concentrationlow concentration

No energy is requiredNo energy is required


Active TransportActive Transport Slide 3 of 6Slide 3 of 6

Active transportActive transport is the movement of is the movement of nutrients from an area of low concentration nutrients from an area of low concentration to an area of high concentrationto an area of high concentration

Energy has to be addedEnergy has to be added to do this! to do this!


Digestion by Digestion by AnimalsAnimals


IngestionIngestion is the process of taking in food is the process of taking in food HydrolysisHydrolysis is the process of breaking down is the process of breaking down

food into smaller pieces and smaller food into smaller pieces and smaller moleculesmolecules

In order for hydrolysis to occur properly, In order for hydrolysis to occur properly, three things are needed:three things are needed:1)1) Digestive enzymesDigestive enzymes2)2) Correct acid pHCorrect acid pH3)3) Correct temperature rangeCorrect temperature range


Digestion by Digestion by AnimalsAnimals


A A hydrolyzedhydrolyzed substance is one that has substance is one that has been digested by hydrolysisbeen digested by hydrolysis

Animals can digest common organic Animals can digest common organic molecules: carbohydrates, lipids, protein molecules: carbohydrates, lipids, protein and nucleic acidsand nucleic acids

Nutrient sources vary from organism to Nutrient sources vary from organism to organismorganism

SubstratesSubstrates Last SlideLast Slide

A A substratesubstrate is a material on which an is a material on which an organism lives, moves or feedsorganism lives, moves or feeds

Some organisms just live on a substrate Some organisms just live on a substrate (e.g. barnacles on rocks)(e.g. barnacles on rocks)

Other organisms just feed on a substrate Other organisms just feed on a substrate (e.g. cheese mould)(e.g. cheese mould)

Some substrates are rich in nutrients (e.g. Some substrates are rich in nutrients (e.g. loam soil)loam soil)

Some algae feed off nutrient-poor Some algae feed off nutrient-poor substratessubstrates

2.2.11

Monitoring Monitoring Water Water QualityQuality

Read pg. 213-222

2.1 Monitoring Water QualityJ. Dulku – Science 9

Water QualityWater Quality Slide 1 of 8Slide 1 of 8

Water that looks “clean” may not be cleanWater that looks “clean” may not be clean There are a lot of toxic dissolved substancesThere are a lot of toxic dissolved substances The monitoring of water quality is an The monitoring of water quality is an

accurate way of keeping track of what is in accurate way of keeping track of what is in water systemswater systems

There are two types of indicators of water There are two types of indicators of water quality: biological and chemicalquality: biological and chemical


Biological Biological IndicatorsIndicators


Biological indicators alert scientists to Biological indicators alert scientists to potential environmental catastrophespotential environmental catastrophes

Two main types of biological indicators:Two main types of biological indicators:1)1) Microorganisms (e.g. bacteria)Microorganisms (e.g. bacteria)2)2) Aquatic invertebrates (e.g. shrimp, Aquatic invertebrates (e.g. shrimp,

worms)worms) InvertebratesInvertebrates are animals without are animals without

backbonesbackbones High amounts of harmful bacteria could High amounts of harmful bacteria could

require water treatmentrequire water treatment


Parts-per-millionParts-per-million Slide 3 of 8Slide 3 of 8

Chemical concentration in the environment Chemical concentration in the environment is usually measured in parts-per-million is usually measured in parts-per-million (ppm)(ppm)

1 particle of a substance is found in 1 1 particle of a substance is found in 1 million particles of solution (air or water)million particles of solution (air or water)

It is calculated as follows:It is calculated as follows:ppm ppm

==solute volume solute volume

(mL)(mL)solution volume solution volume (mL)(mL)

xx 1,000,000 1,000,000 ppmppm

e.g. For 10 mL of solute in 10,000 mL e.g. For 10 mL of solute in 10,000 mL solution:solution:ppm ppm

==xx 1,000,000 ppm = 1,000 1,000,000 ppm = 1,000

ppmppm10 mL10 mL

10,000 mL10,000 mL


Chemical IndicatorsChemical IndicatorsSlide 4 of 8Slide 4 of 8

Six types of chemical indicators may be Six types of chemical indicators may be directly measured:directly measured:1)1) Dissolved oxygen (needed for animal Dissolved oxygen (needed for animal

cells)cells)2)2) Acidity (if pH < 5.0, fish could die)Acidity (if pH < 5.0, fish could die)3)3) Heavy metals (e.g. copper, mercury)Heavy metals (e.g. copper, mercury)4)4) Plant nutrients (e.g. potassium, nitrogen)Plant nutrients (e.g. potassium, nitrogen)5)5) Pesticides (e.g. DDT)Pesticides (e.g. DDT)6)6) Salts (e.g. NaCl, MgSOSalts (e.g. NaCl, MgSO44))


Dissolved OxygenDissolved Oxygen Slide 5 of 8Slide 5 of 8

Oxygen dissolves in water by diffusion from Oxygen dissolves in water by diffusion from airair

Dissolved oxygen is removed by:Dissolved oxygen is removed by:a)a) decomposition (rotting) of organic decomposition (rotting) of organic

materialmaterialb)b) cellular respiration (e.g. fish gills)cellular respiration (e.g. fish gills)

Level of dissolved oxygen depends four Level of dissolved oxygen depends four factors:factors:1)1) temperaturetemperature2)2) wind/water turbulencewind/water turbulence3)3) amount of photosynthesisamount of photosynthesis4)4) number of organismsnumber of organisms


AcidityAcidity Slide 6 of 8Slide 6 of 8

Normal rain has a pH of 5.6Normal rain has a pH of 5.6 Acid rain has a pH less than 5.6Acid rain has a pH less than 5.6 As acid concentration in a water system As acid concentration in a water system

goes up, plant and animal diversity go goes up, plant and animal diversity go down!down!

Fish die if the pH gets as low as 4.5 to 5.0Fish die if the pH gets as low as 4.5 to 5.0 Acid can build up in snow and ice during Acid can build up in snow and ice during

winter, and then release all at once during winter, and then release all at once during springtimespringtime

When this happens, this When this happens, this spring acid shockspring acid shock can weaken the eggs of organisms, killing can weaken the eggs of organisms, killing their youngtheir young


Heavy MetalsHeavy Metals Slide 7 of 8Slide 7 of 8

Heavy metalsHeavy metals are metal substances with a are metal substances with a density of at least 5 g/cmdensity of at least 5 g/cm33

e.g. lead, copper, cadmium, mercurye.g. lead, copper, cadmium, mercury Heavy metals occur naturally in small Heavy metals occur naturally in small

amountsamounts Heavy metals found in large concentrations Heavy metals found in large concentrations

are usually due to humans (e.g. farming, are usually due to humans (e.g. farming, industry)industry)

They can harm the normal development of They can harm the normal development of humans and other organismshumans and other organisms


Consequence of FertilizersConsequence of Fertilizers Last SlideLast Slide

Imagine a water system full of diverse Imagine a water system full of diverse organismsorganisms

Plants are stimulated by nutrients such as Plants are stimulated by nutrients such as phosphates and nitratesphosphates and nitrates

Increased plant growth in a water system Increased plant growth in a water system provides dead organic material for provides dead organic material for decomposersdecomposers

This increases the population of This increases the population of decomposers (e.g. bacteria) and reduces decomposers (e.g. bacteria) and reduces dissolved oxygendissolved oxygen

Finally, the invertebrate population Finally, the invertebrate population dwindles and you only have worms and dwindles and you only have worms and bacteria bacteria

2.2 Monitoring

Air Quality

Read pg. 225 - 227

2.2 Monitoring Air QualityJ. Dulku – Science 9

Air QualityAir Quality Slide 1 of 5Slide 1 of 5

Air quality can be measured in two ways:Air quality can be measured in two ways: Direct measurement of air samplesDirect measurement of air samples Estimation of emissions by Estimation of emissions by

measurement and calculation, at the measurement and calculation, at the sourcesource

Air samples are found to be more accurateAir samples are found to be more accurate Comparison of air samples may serve as a Comparison of air samples may serve as a

warning of environmental changes yet to warning of environmental changes yet to comecome


Culprit How it

formsMajor

SourceHealth Effects

What it Can Form

Solution

Major Air Major Air PollutantsPollutants


Culprit:Culprit: Sulphur dioxide (SO Sulphur dioxide (SO22))How it forms:How it forms: sulphur + oxygen sulphur + oxygen sulphur sulphur dioxidedioxideMajor sources:Major sources: coal, oil, natural gas coal, oil, natural gasHealth effects:Health effects: affects respiratory system affects respiratory system and irritates throat and eyesand irritates throat and eyesWhat it can form:What it can form: smog, acid rain smog, acid rainSolution:Solution: industrial and electrical plants industrial and electrical plants install limestone scrubbers in their stacks to install limestone scrubbers in their stacks to remove 99% of it, forming gypsum (the stuff remove 99% of it, forming gypsum (the stuff in drywall!)in drywall!)




Culprit:Culprit: Nitrogen monoxide (NO), Nitrogen Nitrogen monoxide (NO), Nitrogen dioxide (NOdioxide (NO22))

How it forms:How it forms: nitrogen + oxygen nitrogen + oxygen nitrogen nitrogen oxidesoxidesMajor source:Major source: high heat of vehicle engines high heat of vehicle enginesHealth effects:Health effects: affects respiratory system affects respiratory system and eyesand eyesWhat it can form:What it can form: smog, acid rain smog, acid rainSolution:Solution: it is formed under high heat when it is formed under high heat when ordinary air is sucked into an engine, so no ordinary air is sucked into an engine, so no immediate solution!immediate solution!




Culprit:Culprit: Carbon monoxide (CO)Carbon monoxide (CO)How it forms:How it forms: when there isn’t enough oxygen when there isn’t enough oxygen available to form COavailable to form CO22 during combustion during combustion

Major source:Major source: vehicle engines, combustion vehicle engines, combustion of organic compounds (e.g. wood, natural gas, of organic compounds (e.g. wood, natural gas, fuel)fuel)Health effects:Health effects: headaches, sleepiness, chest headaches, sleepiness, chest pain, brain damage, death (it replaces oxygen pain, brain damage, death (it replaces oxygen in blood!)in blood!)Solution:Solution: better catalytic converters in cars better catalytic converters in cars and industrial plants, home CO detectorsand industrial plants, home CO detectors2.2 Monitoring Air QualityJ. Dulku – Science 9


Last SlideLast Slide

Culprit:Culprit: ground-level ozone (Oground-level ozone (O33))

How it forms:How it forms: oxygen + nitrogen oxides + oxygen + nitrogen oxides + volatile organic compounds (VOC) + sunlight + volatile organic compounds (VOC) + sunlight + heatheatMajor source:Major source: vehicle engines (during the vehicle engines (during the morning rush hour), industrial plantsmorning rush hour), industrial plantsHealth effects:Health effects: breathing problems (it is breathing problems (it is odourless and colourless), long-term lung odourless and colourless), long-term lung injury, crop damageinjury, crop damageSolution:Solution: it is mainly a problem in cities, but it is mainly a problem in cities, but no immediate solution to it!no immediate solution to it! 2.2 Monitoring Air QualityJ. Dulku – Science 9

2.3 Monitoring the

Atmosphere

Read pg. 229 - 232

2.3 Monitoring the AtmosphereJ. Dulku – Science 9

A Greenhouse A Greenhouse EffectEffect


Gases in our atmosphere (HGases in our atmosphere (H22O, COO, CO22 and and CHCH44) take some of the sun’s radiation, and ) take some of the sun’s radiation, and trap it as heattrap it as heat

This is the “natural” greenhouse effect, and This is the “natural” greenhouse effect, and those gases are those gases are greenhouse gasesgreenhouse gases

Greenhouse gases were not originally a Greenhouse gases were not originally a pollutantpollutant

Global warming is one of the reasons why Global warming is one of the reasons why Earth has optimal living conditionsEarth has optimal living conditions

But…what happens when those greenhouse But…what happens when those greenhouse gases increase?gases increase?

An Enhanced An Enhanced GreenhouseGreenhouse


During the 20During the 20thth century, vehicles and century, vehicles and industry increased rapidlyindustry increased rapidly

This resulted in a huge increase in HThis resulted in a huge increase in H22O, COO, CO22 and CHand CH44, and also NO, and also NOxx gases as a gases as a greenhouse gas!greenhouse gas!

This caused the This caused the “enhanced greenhouse “enhanced greenhouse effect”effect”

This is the bad kind of global warming!This is the bad kind of global warming! The average global temperature will go up, The average global temperature will go up,

causing: strange weather, melting of causing: strange weather, melting of glaciers, rise in sea-level, snow in Romania, glaciers, rise in sea-level, snow in Romania, etc…etc…



The Ozone LayerThe Ozone Layer Slide 3 of 5Slide 3 of 5

Remember that ozone is lethal at ground-Remember that ozone is lethal at ground-levellevel

In the upper atmosphere, there is a layer of In the upper atmosphere, there is a layer of ozone molecules (Oozone molecules (O33) called the ozone layer) called the ozone layer

The The ozone layerozone layer absorbs deadly UV absorbs deadly UV radiation by destroying and creating Oradiation by destroying and creating O33 molecules, repeatedlymolecules, repeatedly

Overall, the amount of ozone should be the Overall, the amount of ozone should be the samesame

““Holes” are forming (more like ozone bald Holes” are forming (more like ozone bald spots)spots)


The Ozone LayerThe Ozone Layer Slide 4 of 5Slide 4 of 5

Chlorofluorocarbons (CFC’s) are destroying Chlorofluorocarbons (CFC’s) are destroying ozone molecules more than they are ozone molecules more than they are createdcreated

CFC’s are man-made molecules that release CFC’s are man-made molecules that release chlorine (Cl) atoms into the ozone layerchlorine (Cl) atoms into the ozone layer

1 Cl atom destroys up to 100,000 O1 Cl atom destroys up to 100,000 O33 molecules!molecules!

Ice particles over the south pole are Ice particles over the south pole are speeding up ozone destruction over that speeding up ozone destruction over that areaarea

That is the most noticeable ozone bald spot!That is the most noticeable ozone bald spot!


ComparisonComparison Last SlideLast Slide

The enhanced greenhouse effect and ozone The enhanced greenhouse effect and ozone destruction are two different things!destruction are two different things!

The greenhouse effect is an increase in The greenhouse effect is an increase in Earth’s temperature because of COEarth’s temperature because of CO22, H, H22O, O, CHCH44, and NO, and NOxx

The destruction of the ozone layer means The destruction of the ozone layer means more UV, because of CFC’s that carry more UV, because of CFC’s that carry chlorine atoms!chlorine atoms!

Promise: you Promise: you willwill be tested to see if you be tested to see if you learned the difference!learned the difference!

3.1

Transport of Materials

Through Air, Soil, and

Water

Read pg. 237 - 242

3.1 Transport of Materials Through Air, Soil and Water

J. Dulku – Science 9

Air TransportAir Transport Slide 1 of 4Slide 1 of 4

Chemicals may be transported by the air in Chemicals may be transported by the air in 3 stages:3 stages:1)1) Release at the sourceRelease at the source2)2) Dispersion by wind in the atmosphereDispersion by wind in the atmosphere3)3) Deposition in soil or water, by rain or Deposition in soil or water, by rain or

snowsnow If there is a lot of wind, a chemical may be If there is a lot of wind, a chemical may be

scattered far from the sourcescattered far from the source However, rain or snow may deposit a However, rain or snow may deposit a

chemical and stop it from dispersing any chemical and stop it from dispersing any furtherfurther



GroundwaterGroundwater Slide 2 of 4Slide 2 of 4

PoresPores are the tiny spaces between soil are the tiny spaces between soil particlesparticles

When the pores are connected in loose soil, When the pores are connected in loose soil, we we say the soil is we we say the soil is permeablepermeable

When the pores are full of water, we refer to When the pores are full of water, we refer to the water as the water as groundwatergroundwater

The top of groundwater is referred to as the The top of groundwater is referred to as the water tablewater table

Groundwater can move in any directionGroundwater can move in any direction If groundwater moves slowly, chemicals If groundwater moves slowly, chemicals

build upbuild up



Surface WaterSurface Water Slide 3 of 4Slide 3 of 4

Hazardous chemicals can enter surface Hazardous chemicals can enter surface water through a variety of sources, water through a variety of sources, including the air, industrial sites and storm including the air, industrial sites and storm sewerssewers

Low levels of chemicals are usually not Low levels of chemicals are usually not harmfulharmful

High levels of chemicals can attach to solid High levels of chemicals can attach to solid particles and build upparticles and build up

Chemicals may also be dispersed and Chemicals may also be dispersed and carried away from the sourcecarried away from the source

Organisms may be affectedOrganisms may be affected



Soil TransportSoil Transport Last SlideLast Slide

Chemicals that land on soil may do one of 4 Chemicals that land on soil may do one of 4 things:things: evaporate awayevaporate away be drawn up by plants or ingested by be drawn up by plants or ingested by

animalsanimals travel down streams or roadstravel down streams or roads soak into the ground, forming a leachatesoak into the ground, forming a leachate

LeachatesLeachates may contain lead, may contain lead, hydrocarbons, etc.hydrocarbons, etc.

Chemical reactions may also occur in the Chemical reactions may also occur in the soilsoil

3.2 Changing the

Concentration of Harmful Chemicals in the Environment

Read pg. 243 - 247

3.2 Changing the Concentration of Harmful Chemicals in the Environment


Changing Changing ConcentrationConcentration


If there is a large amount of a chemical, we If there is a large amount of a chemical, we say that that chemical has too high a say that that chemical has too high a concentrationconcentration

The concentration of a chemical may be The concentration of a chemical may be reduced by one of the following:reduced by one of the following:1)1) DispersionDispersion2)2) DilutionDilution3)3) BiodegradationBiodegradation4)4) PhytoremediationPhytoremediation5)5) PhotolysisPhotolysis



Dispersion & DilutionDispersion & Dilution Slide 2 of 5Slide 2 of 5

DispersionDispersion is the scattering of a substance is the scattering of a substance away from its source (e.g. wind blows away away from its source (e.g. wind blows away smoke)smoke)

DilutionDilution involves reducing a chemical’s involves reducing a chemical’s concentration by adding extra air or waterconcentration by adding extra air or water

A river is an example of dispersion and A river is an example of dispersion and dilutiondilution

This is why many industrial plants are built This is why many industrial plants are built next to bodies of waternext to bodies of water



BiodegradationBiodegradation Slide 3 of 5Slide 3 of 5

BiodegradationBiodegradation is the destruction of is the destruction of pollutants by organismspollutants by organisms

One way is to plant rows of vegetation, One way is to plant rows of vegetation, because microorganisms tend to surround because microorganisms tend to surround plant rootsplant roots

Bacteria in soil and water are either:Bacteria in soil and water are either:a)a)AerobicAerobic – requiring oxygen, or – requiring oxygen, orb)b)AnaerobicAnaerobic – not needing oxygen – not needing oxygen

Anaerobic bacteria live in places where Anaerobic bacteria live in places where there is little or no oxygen, like landfill sitesthere is little or no oxygen, like landfill sites



BiodegradationBiodegradation Slide 4 of 5Slide 4 of 5

During winter, biodegradation slows downDuring winter, biodegradation slows down Factors that affect the rate of Factors that affect the rate of

biodegradation:biodegradation:1)1) temperature (warmth is better)temperature (warmth is better)2)2) soil moisture (needed)soil moisture (needed)3)3) pHpH4)4) oxygen (need for aerobic bacteria)oxygen (need for aerobic bacteria)5)5) available nutrientsavailable nutrients

Bioreactors are being built to biodegrade Bioreactors are being built to biodegrade chemicals, and to produce chemicals like chemicals, and to produce chemicals like ethanolethanol



Other MethodsOther Methods Last Slide Last Slide

PhytoremediationPhytoremediation uses growing plants to uses growing plants to soak up chemicalssoak up chemicals

Plants are harvested and burned or Plants are harvested and burned or composted, or the chemicals are recycledcomposted, or the chemicals are recyclede.g. sunflowers and Chernobyl radioactivitye.g. sunflowers and Chernobyl radioactivity

PhotolysisPhotolysis uses light to break down uses light to break down chemicalschemicalse.g. Oe.g. O33, NO, NO22, photodegradable plastics, photodegradable plastics

3.3 Hazardous

Chemicals Affect Living Things

Read pg. 248 - 252

3.3 Hazardous Chemicals Affect Living ThingsJ. Dulku – Science 9

BiomagnificationBiomagnification Slide 1 of 5Slide 1 of 5

Imagine a small fish absorbs a small Imagine a small fish absorbs a small amount of a chemical (e.g. mercury, lead)amount of a chemical (e.g. mercury, lead)

A larger fish eats many of the small fish, A larger fish eats many of the small fish, causing the chemical to build up in the causing the chemical to build up in the larger fishlarger fish

BiomagnificationBiomagnification is the increase in a is the increase in a chemical’s concentration as it moves up the chemical’s concentration as it moves up the food chainfood chain


Crude OilCrude Oil Slide 2 of 5Slide 2 of 5

Crude oil may contain many different Crude oil may contain many different elements and compounds:elements and compounds:a)a) Hydrocarbons (e.g. methane, octane)Hydrocarbons (e.g. methane, octane)b)b) Nitrogen compoundsNitrogen compoundsc)c) Oxygen compoundsOxygen compoundsd)d) Sulphur compoundsSulphur compoundse)e) Heavy metals (e.g. mercury, lead)Heavy metals (e.g. mercury, lead)

Crude oil is separate (refined) by heating it, Crude oil is separate (refined) by heating it, and cooling each componentand cooling each component


Crude Oil SpillsCrude Oil Spills Slide 3 of 5Slide 3 of 5

Crude oil is transported around the world by Crude oil is transported around the world by large tanker shipslarge tanker ships

Unfortunately, tankers run into the same Unfortunately, tankers run into the same problems as ordinary ships, including problems as ordinary ships, including sandbarssandbars

Tankers can crash, causing crude oil to spill:Tankers can crash, causing crude oil to spill:1)1) Lighter compounds usually disperse in Lighter compounds usually disperse in

the air or waterthe air or water2)2) Heavy compounds form “tar balls”: Heavy compounds form “tar balls”:

heavier chunks sink and lighter bits heavier chunks sink and lighter bits wash ashorewash ashore


Exxon Valdez Oil SpillExxon Valdez Oil Spill Slide 4 of 5Slide 4 of 5

In 1989, Exxon Valdez crashed and spilled In 1989, Exxon Valdez crashed and spilled its entire load (260,000 barrels of crude oil)its entire load (260,000 barrels of crude oil)

The crude oil blocked oxygen from diffusing The crude oil blocked oxygen from diffusing into the water, so dissolved oxygen went into the water, so dissolved oxygen went downdown

2% of the oil (over 5000 barrels) made it 2% of the oil (over 5000 barrels) made it ashoreashore

1% dispersed in water, 20% was photolyzed 1% dispersed in water, 20% was photolyzed in airin air

50% was biodegraded, or photolyzed in 50% was biodegraded, or photolyzed in waterwater

Using skimmers and booms, and Using skimmers and booms, and replacement of sediment on the floor, 14% replacement of sediment on the floor, 14% of oil was recoveredof oil was recovered


Spill Clean-upSpill Clean-up Last SlideLast Slide

Reality: no full replacement for crude oil yetReality: no full replacement for crude oil yet Reality: oil tankers, like other ships, may Reality: oil tankers, like other ships, may

crashcrash Reality: oil pipelines rust and crackReality: oil pipelines rust and crack Reality: oil wells occasionally burstReality: oil wells occasionally burst In response, industry has:In response, industry has:

1)1) Learned from Exxon and other spillsLearned from Exxon and other spills2)2) Established emergency plansEstablished emergency plans3)3) Provided hands-on training to workersProvided hands-on training to workers

3.4 3.4 Hazardous Hazardous Household Household ChemicalsChemicals

Read pg. 253 - 258

3.4 Hazardous Household ChemicalsJ. Dulku – Science 9

Household ChemicalsHousehold Chemicals Slide 1 of 4Slide 1 of 4

Even chemicals used at home can be Even chemicals used at home can be hazardous if used or disposed of incorrectlyhazardous if used or disposed of incorrectly

Hazardous household chemicals include:Hazardous household chemicals include:a)a) Various cleanersVarious cleanersb)b) Hygiene productsHygiene productsc)c) Pet-care productsPet-care productsd)d) PaintPainte)e) Pesticides and fertilizersPesticides and fertilizersf)f) Automotive chemicalsAutomotive chemicals


Government RegsGovernment Regs Slide 2 of 4Slide 2 of 4

Government regulations demand the Government regulations demand the following for all chemicals:following for all chemicals:1)1) WHMIS systemWHMIS system2)2) MSDS sheetsMSDS sheets3)3) Proper labels identifying chemicalsProper labels identifying chemicals

Chemicals must be stored in proper Chemicals must be stored in proper locations, away from other chemicals they locations, away from other chemicals they may react withmay react with

No re-use of original containers, or transfer No re-use of original containers, or transfer of chemicals to improper containersof chemicals to improper containers


Government RegsGovernment Regs Slide 3 of 4Slide 3 of 4

New products have regulations before they New products have regulations before they are sold to provide detailed information are sold to provide detailed information about:about:1)1) Intended useIntended use2)2) Physical and chemical propertiesPhysical and chemical properties3)3) Active ingredientsActive ingredients4)4) Instructions & precautionsInstructions & precautions5)5) Side effects and environmental effectsSide effects and environmental effects6)6) First aid informationFirst aid information

Review additional storage and disposal info Review additional storage and disposal info on pages 255 and 258on pages 255 and 258


Transport & DisposalTransport & Disposal Last SlideLast Slide

The person or persons transporting a The person or persons transporting a chemical must be protectedchemical must be protected

Different chemicals must be kept separate, Different chemicals must be kept separate, and away from the occupants of the vehicleand away from the occupants of the vehicle

Original labels should kept attached!Original labels should kept attached! Never pour a hazardous material down the Never pour a hazardous material down the

sink, or in the garbage (organisms may be sink, or in the garbage (organisms may be harmed!)harmed!)

Take wastes to a hazardous waste Take wastes to a hazardous waste collection site, which will incinerate or collection site, which will incinerate or sanitarily landfill itsanitarily landfill it

Documents

Unit C Environmental Chemistry Read pg. 180-190. 1.1 Chemicals in the Environment