topic 4.0 – transport of materials in the environment
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Topic 4.0 – Transport of Materials in the Environment. I. Transport of Materials. A. Transport in Air. Chemical is released. Dispersion (particles scatter in air). Deposition of chemical in soil or water. I. Transport of Materials. A. Transport in Air Factors affecting distribution: - PowerPoint PPT PresentationTRANSCRIPT
Topic 4.0 – Transport of Materials in the Environment
I. Transport of MaterialsA. Transport in Air
Chemical is released
Dispersion (particles scatter in air)Deposition of
chemical in soil or water
I. Transport of MaterialsA. Transport in AirFactors affecting
distribution:Wind – direction and
distance of travelPrecipitation – will
deposit chemical where rain/snow occurs
Where is the healthiest place to live around:
Fort McMurray?
Sherwood Park?
Grande Prairie?
Calgary?
INFO : Particulates can land 30 – 300 miles away from the source!
Does this change your answer?
Does this information change your answer?
I. Transport of MaterialsB. Transport in Surface WaterSurface water – fast moving water (streams, rivers) or
standing water (sloughs, lakes)Solutions that dissolve easy travel far in surface water
Which will carry a toxin further? Where will it be more concentrated?
I. Transport of MaterialsC. Transport in GroundwaterGroundwater – water beneath the surface layer
of soil Slower movement of water than surface How packed the soil is dictates how fast
water flows through this region (usually downwards)
Packed soil = pores which are not connected = slow water movement
Permeable soil – has pores which are connected and allows quick water movement
I. Transport of MaterialsC. Transport in GroundwaterGravel – high porosity (permeability) - allows
water to flow through quicklySandy soil – has med-high porosity-Clay – low porosity – little water movement
I. Transport of MaterialsD. Transport in SoilLeachate – water which has dissolved
chemicals in the soil and carries to the groundwaterThis can contaminate our ground water and
drinking water sourcesAquifier – a source of ground water that has
been naturally filtered but can contain toxins due to leaching
I. Transport of MaterialsD. Transport in SoilCommon Sources and Contaminants
Sources ContaminantsLandfills Heavy metals (lead, mercury,
cadmium)Pipelines Gasoline, oil
Highways Salt, oil
Septic tanks, sewers, livestock wastes
Bacteria, viruses,
Farmer fields Fertilizers – phosphorus, nitrates,
II. Changing Chemical ConcentrationsFive mains ways of reducing chemical
concentrations:1) Dispersion – particles spread out from
where they were released2) Dilution – adding water or air to a
chemical/toxin to reduce the concentration
3) Biodegredation – using living organisms to break down substances Ex. Bacteria, fungi, earthworms>anaerobic – when bacteria degrade without oxygen-in landfill sites>aerobic – when bacteria require oxygen to break down toxins
To speed up biodegredation:Warm temperaturesPlanting plantsUse bioreactorsLots of oxygen
II. Changing Chemical Concentrations4) Phytoremediation
“phyto” means plants“remediation” means cure
Using plants to clean the soil of metals or toxins (they absorb the toxins)
5) Photolysis“photo” means light; “lysis” means break Using the sun to break down compounds
Ex. PlasticsEx. NO2 can form O3
Introduction Qs. What are the 5 methods of reducing toxin
concentration?Why do we want to reduce the concentration
of toxins?How can we dilute a toxin?What is phytoremediation?Would clay or gravel-soil remove more
toxins? Why?What are the conditions that affect how far
an emission is deposited on the ground?
Which is a better method of garbage disposal? Why?
Sanitary landfill or incinerator?
Waste and Toxin managementSanitary landfill – landfill with a clay base
and plastic liner to prevent leachate from entering our water tableIs covered daily with dirt to avoid scavengers
and litter movementIs “flared off” – the anaerobic biodegradation
produces methane, so it is piped to surface and burned off
Incinerator – burning of waste to break down toxic compounds ; can contribute to air pollution
Waste and Toxin managementWastewater managementSewage – waste water from homeSeptic tank – underground container where
bacteria break down materials before released to soil
Sewage treatment plant – treats wastes before re-entering environment
Effluent – treated wastewater which is released to river or lakes
Storm sewers – leads directly to river when sewers are overfilledContain gas, oil, etc from street
Wrap-Up Notespersistent vs. non-persistent
Persistent – toxins that remain in the environment for long periods of time
Point source vs. non-point sourcePoint source – source of pollution is from one
identifiable source Ex. Sewage effluent pipeNon-point source – exact location of source of
pollution is not identifiable Ex. Smokestacks release air pollutants that travel 100’s of km in any direction
Wrap-Up NotesNIMBY – not in my back yard
Where citizens do not support development due to it being too close to their community.
Examples: Electrical powerlines Landfills Chemical plants