pollution Flashcards
what is particulate matter?
a solid that is produced by the incomplete combustion of carbon based fuels such as coal
what are major sources of PM
- transport
- coal & oil powered station
- combustion of forests
- combustion of crop waste
what are the properties of PM
size - density of particles will determine how far they are carried by wind
toxicity - contains heavy metals and toxic chemical
what are the impacts on human health
- smoke particles inhaled
- respiratory diseases such as bronchitis
what are the impacts of plants
- the PM deposits onto the leaves which blocks sunlight so reduced PHS
what are the impacts on the climate
- the particulates reflect incoming solar radiation which leads to a cooling affect on the climate
- decrease in light intensity
- smoke can be an ozone depleting substance
what are the environmental features that affect dispersal and severity of PM pollution
- wind (direction & speed) affects mobility and dispersal
- rain can mobilises into the soil
- temperature = energy suspends PMs in the air
what is a temperature inversion
is a situation in the troposphere where the warm air lies above the cold air
what are scenarios that lead to temperature inversions
- occur in valleys
- low wind velocities
- clear night skies
- mist or fog in day
what is smog
the joining of smoke (PM) and fog
how does fog form
forms when moist air is cooled until is reaches dew points
case study:
what caused the smoke smog in London
coal powered stations
what is a legislation to reduce smog
clean air act 1956 in the UK
what are the pollutants involved in photochemical smog
NOx
hydrocarbons
tropospheric gases
what are the sources of NOx
- high temp combustion and oxidation of N2
- road transport
- energy production and distribution
how does NO2 break down
- UV light splits NO2 through photolysis
- this forms NO and monoatomic O
how does tropospheric ozone form
the monoatomic O combines to the diatomic O2 in the atmosphere to form tropospheric ozone
what are health impacts of tropospheric ozone
burning eyes and throat
what are the impacts to vegetation from O3
- visible leaf damage which leads to premature leaves
- reduced biomass
what are the properties of hydrocarbons
- carcinogenic
- synergistic
how does photochemical smog form
when NOx, hydrocarbons and O3 react together with UV
case study
where did photochemical smog form
LA in 1943
what is acid rain
the combination of pollution problems caused by a range of acidic gases and other pollutants
what are the main gases of acid rain
- oxides of nitrogen
- sulphur dioxide
where does sulphur dioxide come from
the incomplete combustion of coal
what does tropospheric ozone and sulphur dioxide form
sulphur trioxide
name a major contributor and receiver of acid rain
contributor - Poland
receiver - Sweden
what are the properties of acid rain
- toxicity
- synergistic
- solubility in water
- mobile
- state of matter
what are the direct impact on plants
- denature protein & enzymes so reduces PHS
- waxy cuticles can be dissolved
- stomata damage so reduced CO2
what are the indirect impacts on plants
- reduced nutrient uptake e.g. mycorrhizal fungi die
- uptake of toxic materials such as iron and lead
what are the 2 sources of acid mine drainage
- metal mines
- coal mines
how does drainage water become more acidic and contaminated with heavy metals
1.
what are the properties of acid mine drainage
- mobile
- state of matter -> liquid
- pH
- solubility -> contains heavy metals
- toxicity
- specificity = low
impacts of the high acidity
- enzyme inhibition
- similar impacts to acid rain
impacts of heavy metals
- aquatic species (fish) absorb the metals and bioaccumulate them this increases the concentrations in trophic levels
- toxic impacts. mutagenic and carcinogenic`
what is natural gas desulfurisation
is the removal of sulphur from the fuel before it is burned
how does natural gas desulfurisation occur
- the sour gas is run through a tower which contains an amine solution
- the sulfur is removed allowing it to be reused to treat more sour gas
what is crude oil desulfurisation
the removal of sulfur compounds from crude oil during distillation using molybdenum catalysts in the process of hydrodesulfurisation
