Environmental factors affecting the rate of degradation Flashcards
Will two identical amounts of pollutants released in 2 different locations degrade the same?
No as location may change impacts
What is an example of a pollutant that degrades faster in cooler conditions?
CFC’s
What does increased temperature usually lead to?(pollution)
increases the rate of chemical reaction
How does temperature affect breakdown of pollutants?
will break down faster (sewage will rot faster when warmer
what breaks down the polluted sewage?
Microbes
What happens to microbial activity when the temperature increases by 18*c?
doubles
What does warm waste water do to microbial activity?
causes activity to double and increase bio-degradation
What can happen to polluted rivers in summer?
Warmer water increase microbe activity leading to decomposition that uses oxygen causing deoxygenation and dead zones developing meaning oxygen has to be supplied to counter this
What two ways is light important for degradation?
Photochemical fog
Degradation of pesticides
What is photochemical smog?
type of smog produced when UV light from the sun reacts with nitrogen oxides in the atmosphere
What two outcomes are a result of nitrogen oxide emissions form cars?
combines with water to form nitric acid (acid rain)
reacts with sunlight to produce monatomic oxygen that combines to produce ozone
Is photodegradation an abiotic or biotic process when degrading pesticides?
Abiotic
How does photodegradation of pesticides occur?
Molecules in pesticide become more active and vibrate more as they absorb light energy causing range of reactions and degradation
What is oxygen vital for?
Aerobic decay of organic waste
What non-organic compound dopes oxygen react with?
Sulphide ores to produce sulphur dioxide
What is oxidation?
chemical process or reacting with oxygen
Why do we know oxygen is reactive?
Important part of combustion
remove oxygen to put of a fore
What is a catalyst?
Substance that speeds up a reaction but doesn’t affect the outcome
How does pH affect pollutants?
affects solubility of range of heavy metal
what are some examples of heavy metals?
Iron
Lead
Mercury
What does more acidic water do to heavy metals?
allows them to become more mobile which is bad
How can pH / acidity of water be reduced?
can be neutralised by basic or alkaline rocks
what is a good option that can be used to neutralise acidic water?
Limestone- where limestone beds do not underlie the area limestone chips can be used
How can the presence of other chemicals affect pollution/ pollutants?
When other chemicals are present they may bind to the pollutant either helping to degrade it or it may cause it to form a new, secondary pollutant
How are PANs a good example of other chemicals affecting. pollutant?
they are produced in the atmopshere when oxidised volatile organic compounds combine with nitrogen
why is adsorption a good thing?
may prevent the pollutant from being so harmful as it immobilises it
What is an example of a good adsorbent material?
clay which can be sued to bind heavy metals once bined they do not leach into water or end up in the atmosphere
What is an example of where the presence of an adsrobent material reduced the effects of pollution?
After the Chornobyl accident in 1986 radioactive caesium was washed out of the atmosphere by rain caesium bound to clay in the soil immobilising it helping reduce the radioactivity if the air but soils still remian radtioactive (will do for 3000yrs)
