unit 3: science 9- environmental chemistry Flashcards
MSDS’s
Material safety data sheets
They are a form of label that gives information about the harmful substance to the buyer of the product
If describes precautions that should be taken when handling, using, transporting and disposing of the product
It also provides details about heal effects and how to contain or store the product
Transport of hydrocarbons in soil
Contamination of soul by hydrocarbons is a problem throughout Canada
Hydrocarbons are from vehicles and in industry… They contaminate by being carried through water in the soil and spread over a wide area. They can concentrate inside the pores of the grains and not travel very far but cause a difficulty to clean up
Most hydrocarbons are toxic to plants, animals and humans
Impact of the oil spill on people
Many commercial fishers could no longer sell fish
People who relied on wildlife for food ha to purchase food instead
Tourism decreased due to loss of recreation in an oil spill area
All of these effects caused a long term clean up to fully repair most of the damages done by the spill
Factors affecting biodegration
Slow biodegration in the winter due to little bacteria growth
Other factors other than temp are soil moisture, pH, oxygen supply and nutrient availability
You can plant vegetation to help with the biodegration process
Storage of hazardous chemicals
Leave all products in organizational containers (secured lids) and labels
In a location out of reach from children
Store in cool, dry, ventilated places
Don’t store flammable substances in glass containers or substances such as gasoline should be stored outside of the house
Store different substances on separate shelves from each other
Discard of containers that are leaking or substances that are old
Dispersion
The scattering of a substance away from its source
Ex. If you spilled to much fertilizer on your lawn you could disperse it throughout the soil
Some substances that contaminate groundwater
Minerals in rocks and soil: iron, calcium
Organic substances ( natural or human made): pesticides, solvents
Leached from landfill sites: heavy metals (mercury)
Leak from underground storage or pipelines: gasoline, oil
Inorganic substances( industrial processes ect.): salt, fertilizers
Improper micro-organisms: bacteria, viruses
Household chemicals: detergents, nitrates
What dilutes or disperses a chemical quickly?
A fast flowing river or air mass
Dilution or dispersion combined with another clean-up process such as biodegration can be very effective
Crude oil spills
Exxon Valdez is a good example…
Occurred in prince William sound and changed the beauty of the lake
The small molecules oil spilled and dispersed into the air and water
Tar balls of heavy hydro garçons were washed ashore or sank into the sediment under the water
This is a long term problem and caused a major impact on the environment
Factors that affect the rate of groundwater
The soil had pores.. These pores are tiny spaces between soil grains that are sometimes tightly packed that the pores are not connected. In this case the water cannot flow through the soil as easily. If the pores are connected the soil is permeable and transports pollutants through the water more easily.
Transport in groundwater
Water that soaks into soil moves first into a zone near the surface where the soil grains contain both air and water (water table) Next it will move deeper and enters a zone where all the spaces are filled with water (groundwater)
Groundwater can move sideways, up and down
The water can exonerate concentrated with substances such as lead and creates problems to drink the water and use for other purposes
Impact of oil spills on plants and animals
Floating algae can be killed, invertebrates near shore could not survive due to decreased oxygen, loss of food and the toxic effect of hydrocarbons
Fish eggs and young fish were sensitive to the oil and died
Adult fish could escape by swimming away but the lost their habitat and good resources
Seabirds and mammals can become covered in oil so many of them would die as well
Biomagnification
Increase in concentration of a chemical or element as it moves up the food chain
Ex. Mercury: comes from emissions from coal-fires power plants ect. The mercury falls into fresh or salt water where bacteria join it to an organic molecule that alga can absorb
After this point mercury enters the good chain through the alga and leads to insects, green plants and fish. Eventually making it onto our plates and harming humans
Mercury contaminated water is a problem in Canada’s Great Lakes
Oil spill clean up
Booms am be used to clean up and obtain the spills in water
Ground spills occur too and have different procedures to clean up the spills
Crude oil
A mixture of many chemicals
Contains hundreds of different molecules in all shapes and sizes
Some in crude oil contain nitrogen, oxygen and sulfur
Crude oil cannot be used right when bit comes out from the ground.. It had to be refined through a process
Concentration of pollutants in the environment can be changed using different techniques such as..
Dispersion, dilution, biodegratuon, phytoremediation and photolysis
Hazardous chemicals include
Household cleaners Personal hygiene products Pet-care products Paint and paint products Pesticides and fertilizers Automotive fluids
New product regulations
Intended use, physical and chemical properties and active ingredient(s)
Instructions for use, safety precautions
Heal effects, environmental effects, toxicity to humans and first aid instructions in case of poisoning
Transportation of consumer goods
Should be placed in the trunk of a car where they will not fall over (secure)
Do not mix together hazardous household wastes when bringing to a collection site
Factors of the direction and distance of airborne pollutants
Pollutants properties, wind speed, and the direction of prevailing winds
Disposal if hazardous chemicals
Never pour wastes down the drain or into the soil
Do not throw them away in the garbage
If you do pour the substance down the drain it can enter into the sewage system it septic tanks and not be filtered, therefor they are entering into the surface water and harming the soil water, drinking water and even air
Aerobic and anaerobic biodegration
Aerobic: uses oxygen in the air to grow and produce bacteria for breakdown
Anaerobic: without oxygen in the air to thrive the breakdown with bacteria
Solid waste garbage
Some substances such as gasoline and oil can be recycled at a hazardous waste collection site
Take antifreeze to a recycling centre and don’t out it into the ground or drain where it will enter into your septic tank
Never place car batteries in a home garbage. They can be recycled
Take care or aresol cans, syringes, fertilizers, pesticides and paint products by putting them in a hazardous materials collection site
Transport in air
Release of the chemical at the source
Dispersion if chemical in the atmosphere
Deposition if the chemical in soil or water
The distribution of airborne pollutants may be limited by lack of wind, precipitation.
The pollutant will be depositors closer to its source if it is carried to the ground by rain or snow
It is hard to identify a pollutant that had travelled thousands of kilometres. Due to the movement of these chemicals it has become an international problem in which they are signing agreements to limit the amount of airborne pollutants.
Transport in the soil
Water landing on a field or your yard does four things:
Some evaporates
Some soaks into the soil and is taken by plants
Some runs into the street or stream
Some soaks though the soil, moves downwards, dissolves substances in the soil and carries them along
These substances are called leachate
Composition of soil can affect this: if packed closely- harder to leachate, if not packed- most likely to leachate compared to packed clay
Acids or other hazardous chemicals in the soil can neutralize organic substances such as broken down leaves that become organic material
Photolysis
The breakdown of compounds by sunlight. Some substances degrade from exposure to light
Ex. Photodegradable plastic: problem is that it will not break down if buried and out of sight from sunlight
Phytoremediation
Green plants can be used to remove or degrade hazardous materials
It reduces the concentration of harmful chemicals in the soul or groundwater
Plants can be used to clean up metals, hydrocarbons, solvents, pesticides, radioactive materials, explosives and landfill leachates
Dilution
Reduces the concentration of a pollutant by mixing the polluting substance with large quantities of air or water
Ex. If you drip some bleach into a sink of water it will dilute into the water and spread the molecules
Government regulations
Designed to protect consumers and reduce the risks of transporting,storing,using and disposing of hazardous materials
Hazardous waste collection sites
Found in almost all of Alberta communities
Wastes such as paints and fertilizers will be taken to theses sites for disposal
Materials that cannot be recycled will be safely packaged in large containers where they are sealed with later
Biodegration
Nature uses living things to clean up the environment
Organisms such as earthworms, bacteria and Fungi help the biodegration of most organic substances degrade
Algae live at the soil surface can use the broken down substance as organic compounds through photosynthesis for food
Carbon atoms in these molecules can be used to build compounds such as carbohydrates and protein
Transport in surface water
Potentially hazardous chemicals can enter the surface water from different sources such as air, groundwater, runoff from different sites, and the outflow from sewage treatment plants
These chemicals can be dispersed throughout the surface water by these sources becoming attached to solids and can build to in lakes or river bottoms, affecting organisms
We need to track and monitor the water continually due to this issue
Nitrogen oxides
Also air pollutants which form smog and acid rain
Like sulfur dioxide that affect our health by irritating the respiratory system and eyes
Formed mainly from the combustion in vehicles
Sulfur dioxide
Is an air pollutant that forms smog and acid rain
Can affect respiratory system and irritate eyes
Major source is industrial processes such as oil and gas industry, burning fuels such as coal, oil and natural gas
Combine with oxygen to form nitrogen which is harmful to plants, animals and non living objects (major air pollutants)
Pesticides have changed:
Because pesticides may be toxic scientists are designing new ones that last only one growing seasons and are broken down by bacteria
Some insects have become resistant to pesticides and build their generation to e resistant as well
Not all pesticides break down entirely in the environment, this causes the tissues of organisms to accumulate and cause serious health problems
Spring acid shock
The Canadian Shield has been affected by acid precipitation which causes acid deposition
In areas where acid precipitation is a problem it deposits into snow and ice in the winter. In the winter the snow and ice melt, therefor the water flows into streams and lakes… This is known as spring acid shock
Carbon monoxide
A colourless and odour less gas and is known as the silent killer
Main source is form human activity in noter vehicles
Other sources include: combustion of wood, natural gas, industrial processes, airplanes and forest fires
Dangerous because it reduces the amount of oxygen carried by the blood if inhaled and may result in headaches, sleepiness, chest pains, brain damage and even death
Microbiological indicators
Organisms such as bacteria cause serious health problems if they are present in large numbers
Samples of water are taken and tested for microorganisms… If the count is high the water requires additional treatment before it is considered for for humans
Not a good indicator of water quality:
Clarity is not a good indicator of water quality because clear water can sometimes be harmful to humans and other organisms
Ex: lakes affected by acid rain are crystal clear and lifeless
The ozone layer
Occurs in high in the earths atmosphere15-20 km above the surface
This ozone absorbs ultraviolet radiation which is a good thing
As the ozone layer became thinner over the years, more UV radiation is allowed to reach the earths surface, which is a bad thing. This can cause a harmful effect in organisms:
Increased risk if skin cancer in the cataracts in humans
Plankton in the sea are sensitive to UV radiation could die off of exposed to large amounts. This would affect all the animals that feed on plankton
Water quality is determined according to the 5 categories:
Human drinking water Recreation/swimming Livestock drinking water Irrigation Protection of aquatic life
Parts per trillion
(ppt) is difficult and requires special costly equipment
Only extremely hazardous substances are measured to this level of concentration
Aquatic environments
Diversity of all organisms decreases as acidity increases and dissolved oxygen decreases
If the pH in the water is below 5.0 there will not be many fish
Few insects and many worms may mean that the water contains little dissolved oxygen
Factors that can affect the amount of dissolved oxygen is an increase in…
Phosphorus and nitrogen in the water
This can cause increased growth of algae and green plants
As most algae in green plants grit more die
Bacteria is decomposing the dead material
The bacteria increases the usage of dissolved oxygen in the water
When the dissolved oxygen decreases many aquatic organisms decrease
Catalyst converters
Are used in vehicles to convert carbon monoxide into carbon dioxide
This creates a problem in the high levels of carbon dioxide being released, in increasing greenhouse gases and global warming
Gypsum
A useful product that is recovered and used in manufacturing
Greenhouse gases
Gases in the upper atmosphere which trap the heat are called greenhouse gases
Water vapour, carbon dioxide, methane and nitrogen oxides are all greenhouse gases
LD50
Used to compare toxins…
LD stands for lethal does and 50 stands for 50%
It is the amount of a substance that causes 50% of a group of test animals to die if they are given a specified does if a substance
Global warming
When greenhouse gases accumulate in the atmosphere the overall temp of the earths surface
Caused by:
Human activities- Burning fossil fuels ect.
Natural events-volcanic eruptions, forest fires ect.
Some countries are attempting to reduce carbon dioxide emissions:
Windmill farms- use power turbines rather than burning fossil fuels
Forest projects- growing trees absorb the C02, reduces in environment
Chlorofluorocarbons
Scientist Believe that the thinning of the ozone layer is a result of chemicals humans call chlorofluorocarbons (CFC’s)
Have been used in refrigerators, aerosol cans ect.
When CFC’s reach the upper atmosphere, UV radiation breaks chemicals down into substances such as chlorine that destroys the ozone. One chlorine atom can destroy 100000 ozone molecules
International agreements have been signed by many countries in an attempt to reduce CFC’s
The enhanced greenhouse effect
Effect that is made greater by human activities such as burning fossil fuels and clearing land that add the gases in more concentrated amounts to the atmosphere
Water vapour and then carbon dioxide contribute most to the enhanced greenhouse effect
Ground level ozone
Layers of ozone in the upper atmosphere protect the earths surface from harmful chemicals
However ground level ozone is a harmful pollutant
Ozone is a odourless and colourless gas made up of 3 oxygen atoms
At ground level the ozone reacts with oxygen, nitrogen oxides and volatile organic compounds
Ozone pollution is a problem mainly in larger cities during the summer where there are many automobiles and industries
Ozone is harmful to people with lung diseases ( asthma)
Ground level ozone can seriously affect crops such as wheat, soybeans and onions
Ozone can also cause materials such as plastic to deteriorate more rapidly
What factors affect aquatic organisms
Chemical factors:
These are indicators if water quality-
Dissolved oxygen
Acidity
Heavy metals
Plant nutrients such as nitrogen & phosphorus
Pesticides
Salts such as sodium chloride and magnesium sulfate
The concentration if chemicals in the environment is usually measured in parts per million (ppm)
Biological indicators
Scientists use organisms that live in water to help determine water quality
These indicators can be:
Microbiological indicators
Aquatic invertebrates
Lakes change due to…
They become cloudy in the summer because of excessive algae growth
It reduces the oxygen content in the lake, effects the types of organisms that live there
Ex. Trout is one of the first fish to die when the concentration of dissolved oxygen decreases
Scrubbers
Are used on industrial and electrical generating plants to reduce sulfur dioxide emissions
Use limestone (calcium carbonate) to convert sulfur dioxide to gypsum
Combine with oxygen to form nitrogen which is harmful to plants, animals and non living objects (major air pollutants)
Remove up to 99% of sulfur dioxide emissions
The greenhouse effect
When radiant energy from the sun reached earths surface much of it is reflected back into space. Some of the energy is trapped near the Earths surface by a layer of gases that act like glass in a green house
Monitoring air quality
Determined in two ways:
Measuring levels of pollutants in the air
Estimating the amount of emissions from pollution sources
Dissolved oxygen
Is essential for the health if aquatic life such as fish, insects and micro-organisms
Levels of dissolved oxygen depend on:
Temp
Turbulence due to wind or speed of water
Amount of photosynthesis by plants and algae in water
The number of organisms using up oxygen
5 milligrams per litre (5ppm) of dissolved oxygen will support most aquatic organisms
Aquatic invertebrates
Invertebrates are animals without backbones are one group of indicator organisms
Crustaceans, worms, insects and mollusks are invertebrates
Carbon dioxide
Is naturally present in the air so it is not normally considered a pollutant
Heavy metals
They can be toxic
Mercury belongs to this group
They are called heavy metals because they have a density greater than 5g/cm3 this means they are five times more heavier than an equal volume of water
These metals accumulate into the bodies if organisms and cause health problems
Humans change chemicals in the environment
Chemicals formed by human activities such as…
Agricultural activities
Solid wastes All form pollution!
Waste water
Fuel combustion
Industrial processes
pH scale
Measures the acidity if a substance
The pH of 13 means that a solution is basic- neither acidic or base
Acids
Compounds that dissolve water to form a solution with a pH lower than 7
Base
A compound that dissolves in water to form a solution with a pH higher than 7
Hair condition and household cleaning products are bases
Pollution
Any change in the environment that produces a condition that is harmful to living things
Ex: oil spills in a lake ecosystem affects organisms
Smog from vehicles makes breathing difficult for humans and certain animals
Carbohydrates
Organic molecules made up of atoms of carbon, hydrogen and oxygen
What certain elements do for humans
Nitrogen: composition of proteins and nucleic acids found in all cells, growth and repair of tissues
Phosphorus: composition if bones, teeth and DNA, many metabolic reactions
Potassium: muscle contraction and never impulses
Magnesium: composition of bones and teeth, absorption of calcium and potassium
Animals break down food in two ways…
Mechanical- chewing food
Chemical- occurs in the mouth, stomach and small intestine with the help of enzymes that speed up chemical reactions
Cellular respiration
Plants and animals need oxygen to carry our cellular respiration
Cellars in your body consume food and oxygen to create C02 and energy
Is a natural process that exists in both plants, animals and humans
How many elements do our bodies need for normal growth?
25 elements
Form complex molecules that form sugar, starch, fat, oil, wax and proteins
Optimum amount
Amount of a substance that provides an organism with the best health
PH number
Indicates the acidity of a solution. It is a measure if the concentration of hydrogen ions in a solution
PH meter
A tool that measures the pH of a substance that consists of using a probe which is submerged into the solution
What nine elements are essential for the normal growth in plants?
Obtained by air or water:
Carbon, hydrogen, oxygen
Obtained by the soil:
Nitrogen, phosphorus, potassium, magnesium, calcium, sulfur
Hydrolysis
The breakdown or digestion if large organic molecules
A substance which is broken down had been hydrolyzed
Processes and activities that may be harmful to living things include
Natural processes: forest fires, volcanoes
Human activities: gasoline, electricity and pesticides
Nitrogen cycle
Plants can use nitrogen only when it is combined with other elements such as hydrogen and oxygen
Air is about 78% nitrogen in the form of nitrogen gas
Plants can’t use “free” nitrogen directly. It had to be “fixed” into other compounds with other elements
The concentration of usable nitrogen can be removed by..
Conversion- to free nitrogen by bacteria
Water- carrying dissolved nitrogen compounds deep into the soil, making it unavailable to plants
Nitrogen can be added to souls that lack it by:
Planting nitrogen-fixing plants such as clover and alfalfa it add certain fertilizers
Solid waste
Included garbage that is collected from:
Households, industrial plants, commercial buildings, institutions, construction/demolition sites
Some solid waste can be reused or recycled
Most solid wastes are placed in landfill sites
Osmosis
A passive transport method: process that is a type of diffusion, by which water molecules move across a cell wall/membrane from an area where there is more water molecules to an area where there are fewer water molecules
Substrate
The material on which an organism moves or lives
Ex. The sea anemone attaches itself it rocked where it can obtain rich nutrients grin the intertidal zone
Bread mild obtains materials from the nutrient rich substrate that it lives on
Some lichens and aka gar are able to obtain in nutrient poor substrates such as bare rocks or snow
Acid rain
Industrial processes create many chemicals which go into our atmosphere… These chemicals dissolve in water droplets to from acids. When the acids fall back to earth it is known as acid rain
Sulfur dioxide + water- sulfuric acid
Nitrogen oxides + water- nitric acid
Carbon dioxide + water- carbonic acid
Causes lakes and streams to become acidic which harms aquatic life
Causes buildings and monuments to deteriorate
Organic compounds
Complex molecules that contain carbon
Ex. Fossil fuels ( petroleum, natural gas and coal)
Four most important classes:
Carbohydrates, lipids, proteins and nucleic acids
How do nutrients enter the plant
Through passive or active transport
Passive: does not require the plant to use any energy
Active: plants must use energy to move the molecules if nutrients in the direction opposite to diffusion. To maintain their concentrations, plants have to receive nutrients from the soil area and lower concentration in the roots
Willow bark usage in the past/future
Used willow bark tea as a medicinal drink for F.N in the past
A synthetic version of salicylic acid was developed by the Bater company and named it Aspirin
Ingestion
The process if taking did into our bodies
What certain elements do for plants
Nitrogen: composition if proteins and chlorophyll, leaf and stem growth
Phosphorus: root and flower growth, cellular desperation and photosynthesis
Potassium: stimulation of early growth, starch and protein production and sugar movement, disease resistance, chlorophyll production and tuber formation
Magnesium: composition of chlorophyll structure
Universal indicator
A tool that measures pH but is a mixture of indicators that change colour over a wife pH range
Acid-base indicators
A tool that measures pH and are special substances which may change colour when paved in a solution
Blues litmus paper turns red in an acid
Red litmus paper turns blue in a base
Plants produce sugar which is used as food, this requires?
Carbon dioxide and water
Steps of nitrogen fixation
After nitrogen fixation occurs, plants use the nitrogen-containing compounds animals then eat the plants
Animals use the nitrogen to make complex substances such as proteins
Decomposes break down the large nitrogen compounds in the soil
Nitrogen can moved from organisms and back into the soil several times
Eventually some nitrogen compounds are broken down by bacteria in soil
The nitrogen is released back into the environment as free nitrogen and the cycle begins again
Benefits if acids
Vinegar is a weak acid
Lemons are acidic
Some plants grow better in acidic soils
Proteins
Are used by organisms for growth and repair and as a source of energy
A organic compound made up of units called amino acids
Agricultural activities/ fertilizers
Fertilizers: substances that ene riches the soil so that plants will grow better
Contain major nutrient elements such as: nitrogen, phosphorus and potassium
The three numbers 15-30-15 means that the fertilizer contains
15% nitrogen
30% phosphorus
15% potassium
Some fertilizers have an S on the label to indicate that it contains sulfur as a major ingredient
Too much fertilizer can damage a crop or enter ponds water where it would damage the ecosystems
Waste water
Sewage: waste water contain dissolved and un-dissolved materials from your kitchen, bathroom and laundry
Septic tank: an underground container where bacteria break down The organic materials before they are moved into the soil
Sewage treatment plant: treats waste from homes, businesses ect.
Effluent: also known as treated waste water and is released into rivers or lakes
Micronutrients
(Small) are needed in minor or trace amounts
Hippocrates
Known as the father if medicine
Recommended willow bark be used to treat pain and fever
Lipids
Fats, oils and waxes composed of mainly carbon, hydrogen and oxygen atoms
Nitrogen fixation
Is the process if changing free nitrogen so that the nitrogen atoms can combine with other elements to form compounds that organisms can use
Carried our mainly by bacteria in the soil
The bacteria separate two nitrogen atoms that form nitrogen gas
Some plants that are very good at nitrogen fixation include: beans, clover and alfalfa
Once the nitrogen has been fixed, meaning that the nitrogen atoms have separated, the nitrogen can form compounds with other elements
Lighting also convert nitrogen in the air to nitrogen compounds that plants can use
Diffusion
A passive transport method: the movement of molecules from an area of higher concentration to one of lower concentration
Some nutrients may move from an area if high concentration outside of the roots to an area of low concentration within the roots
Macronutrients
Nutrients and elements that are needed in relatively large amounts
Neutralization reaction
Produces water and a compound called salt
An antacid is a mild base that reacts with stomach acid to neutralize it
Acid lakes are sometimes treated with line to neutralize them
Pesticides/agricultural
Chemicals that kill pests. A pest is an organism that harms people, crops or structures
Herbicides- kill or control weeds
Insecticides- kill or control insects
Fungicides- kill fungi
Cream problems such as being not selective which will kill both pest and non peer species
Pests can sometimes become resistant to pesticides if they have been there for a long period of time
Sanitary landfill
Prevent waste chemicals from going into the soil
Uses plastic liners and compacted clay to prevent the chemicals from going into the groundwater
Nucleic acids
Are the largest and most complicated molecules found in living things
All cells contain two important nucleic acids: DNA and RNA acids
Play a major role in heredity and in controlling a cells activities
Inorganic compounds
Substances that do not contain carbon
Ex. Baking soda
