Topic 10: Oil Pollution Flashcards
Give 3 causes of oil pollution
Waste lubricating oil
Accidental release
Oil exploration
Explain where waste lubricating oil that is a cause of oil pollution, comes from?
Vehicle engines lubricating oil either leaks or is discarded deliberately into the environment
Industrial machine oil which is washed into drains or mixed with other effluents
Where can accidental releases of oil come from?
Shipping accidents, especially oil tankers
Oil rig accidents
Oil pipeline leaks
Leakage from storage tanks
Discharge of waste water from washing tanks on ship tankers
How does oil exploration lead to oil pollution?
Drilling
Drill pipes are lubricated with fine clay suspended in water to reduce friction when they bore through rocks
Sometimes oil based clays are used
How can oil pollution affect organisms that live on or in the water?
- some components of crude oil are toxic like benzene and xylene, planktonic organisms are most likely to be affected
- oil can cover aquatic life on sea surface
- this can lead to the asphyxiation of molluscs and crustaceans
Algae on the seashore would be unable to absorbe the reactants for photosynthesis
How can oil pollution affect birds ?
Severe oil covering can cause them to drown
Oil can stick their feathers together so they lose insulating properties and can die of hypothermia
They might try and clean off a small amount but that can reduce the time available for finding food for them and their young
How can oil pollution affect aerobic organisms?
It can form a thin layer on water which reduces the amount of oxygen that can dissolve in water from atmosphere which can reduce the survival of aerobic organisms there
How can marine organisms be affected by oil pollution?
The masking odour and narcotising effects of oil can make it more difficult for marine organisms that use their sense of smell to find food and mates
Give 5 ways that oil pollution can be controlled
Prevention of oil releases
Improved oil tanker operation
Improved tanker design
Oil interceptors
Bund walls
Explain how oil releases can be prevented in order to control oil pollution
By recycling waste lubrication oil
Contaminants can be removed, chemical reforming and distillation can produce chemically valuable lubricants again
How can oil tanker operation be improved to control oil pollution?
Better shipping routes
Better navigation systems
Inert gas systems
Tank washing procedures
Oily waste water disposal
How can better navigation systems improve oil tanker operation?
The AIS (automatic identification system) allows the position of the ships to be monitored and coordinated to help avoid collisions
How can tanker design be improved in order to control oil pollution?
Double hull
Twin engine/rudder/fuel tanks
Seperate oil and ballast tanks
Why is double hulls an example of improved tanker design?
It makes any damage to the hull of the ship less likely to release oil into the sea
What are oil interceptors and how can they control oil pollution?
They seperate oil from watery waste e.g from drainage water from major roads or from car parks
The water still flows into main drainage system or river but is retained and can be removed for later treatment
What happens to oil that is spilt in turbulent conditions in open water?
Most is dispersed in a few days or weeks
Lighter fractions can evaporate
Medium fractions will gradually be digested by bacteria
Heavier fractions might remain as tar balls for years
When is oil pollution most serious?
When it occurs inshore or in an enclosed body of water because dispersal is prevented
Areas with more sensitive ecosystems
Give 7 ways that oil spills can be treated
Booms
Skimmers
Absorbent materials
Detergents/dispersants
Polymerising agents
Steam washing
Bioremediation
What are booms and how can they be used to treat oil spills?
They are inflatable tubes that restrict the movement of floating oil
A ‘skirt’ below can retain oil if there is a water current
Where can and cant booms be used?
They dont work in open water where currents/waves are too strong
Mainly used in sheltered areas where they can reduce dispersal of oil from the pollution source or protect sensitive sites
What are skimmers and how can they be used to treat oil spills?
They are rotating metal discs that pick up oil that can be scraped off and stored for later disposal by incineration or landfill
What are absorbent materials and how are they used to treat oil spills?
High surface area materials like textile mops can help absorb oil
The absorbent material and oil can be removed and disposed of by incineration or in landfill sites
What are detergents/dispersants and how can they be used to treat oil spills?
They break up the oil to produce an emulsion of oil droplets in water
They allow oil to become more mobile and disperse, possibly to be broken down by bacteria
But they dont reduce amount of oil pollution
How are detergents and dispersants spread?
At sea by aircraft and ships
Using backpack sprayers on the shore
What are polymerising agents and how are they used to treat oil spills?
Chemicals have been developed that cause oil molecules to join together
This produces more solid materials that can be collected more easily
What is steam washing and how can it be used to treat oil spills?
Used to wash oil on beaches off
It doesnt destroy it but removes it from particularly sensitive habitats
What is the issue with the steam jets in steam washing?
They may kill organisms deeper in beach sediments that weren’t affected by the oil
What is bioremediation and how is it used to treat oil spills?
Some bacteria breakdown hydrocarbons and help remove the residual pollution left after other clean up methods are used
when may bioremediation be accelerated?
Higher temperatures, oxygen and nutrient levels
