environment Flashcards
what is residence time
the average time a substance or mass spends in a specific place or medium
how do you calculate residence time
= amount of substance in the reservoir / rate inflow or outflow
does acid rain have short or long residence time
short, fairly local phenomenon,
what does acid rain cause soils to emit
Al3+
what is smog
combination of smoke and fog in the atmosphere made up of nitrogen, sulphur oxide, ozone …
examples of primary pollutants
volatile hydrocarbons
nitrogen oxides
examples of secondary pollutants
ketones
aldehydes
ozone (O3)
what is temperature inversion
cooler air skips underneath warmer air so the layer of war air is trapped inbetween 2 layers of cool air.
this causes any pollutants released in that layer of cooler air stay close to the earths surface. which allows the primary pollutants to react and produce secondary pollutants and smog
what is the normal condition in the Throposohere
temperature decreases as you go up. the warm and less dense air rises and takes pollutants with it.
the warmer air is then replaced with cool air which is again warmed up continuing the process.
what are the effects of PANs which can be found in smog
cause eye irritation and respiratory problems.
what are 4 air pollution concerns
ozone hole
global warming
acid rain
smog
name 4 fossil fuels we need to clean up
SOx
coal
NOx
soot (e.g. for diesil engines)
what is used to remove SO2 from the emissions of power plants
flue gas desulphurisation
how does the flue gas desulphurisation work
reacts flue gas with limestone
how can NOx emissions be reduced considerably
2 stage combustion technology
1st stage - high temperature and low O2. (not enough O2 to react with N2)
2nd stage - Excess O2, but low temp so that N2 cannot react to give NOx
how do power station remove NOx
they use ammonia
4NH3 + 4NO + O2 -> 4N2 + 6H2O
name 4 chemicals which impact to road pollution
NOx
particulate matter
CO
unburnt hydrocarbons
what is a three way catalyst
devise which reduces emissions from gasoline fuelled vehicles
what are the 3 tasks of a 3 way catalytic converter
- reduction of nitrogen oxides
- oxidation of CO -> CO2
- oxidation of unburnt hydrocarbons
what helps reduce harmful emissions from diesil engines
adblue
what is the definition of a critical element
elements crucial for technology development and the production of advanced energy.
what are 4 examples of critical elements
helium
lithium
phosphorus
zinc
platinum