Flashcards
Acid Rain
Flashcards do conjunto (6)
- 1BackgroundAll rain naturally acidic, pH 5.6. Due to CO2 producing dilute carbonic acid. Acid rain given to rain with pH more acidic than 5.6. Combination of pollution problems by range of acidic gases and their pollutants.
- 2Pollutants involved in acid rainMain gases: Sulfur dioxide - dissolves in water, producing sulphorous acid. Oxidised by ozone, producing sulphur trioxide, then dissolved to produce sulphuric acid, more powerful than sulphurous acid. NOx dissolve to produce nitrous and nitric acids.
Other gases: hydrogen chlorine dissolves producing hydrochloric acids. Ozone involved in oxidation of SO2 to SO3 which harms plants directly. - 3Effects of acid rain on non-living organisms-Acid decomposition corrodes metals; damages railway lines, water pipes, power lines
-Limestone structures damaged by acids as dissolve surface layers, weaken stone structure - 4Effects on living organisms-Direct effects: low pHs denature proteins and inhibit enzymes, tissues directly exposed are more likely to be damaged, exoskeleton organisms may die as acids dissolve calcium compounds forming them, lichens sensitive to acidic conditions - can be used to monitor acid rain pollution, SO2 can cause breathing difficulties
-Indirect effects: more soluble at low pH, leach metal ions from soil so important plant nutrients are lost, toxic ions inhibit enzyme action in plant root hair cells and may be leached into rivers and lakes, metal ions can affect human health, aluminum associated with neurological disorders - 5Control of oxides of sulfur-Natural gas desulfurisation: removes sulfur from fuel before burnt
-Natural gas: hydrogen sulfide removed from gas after extraction
-Crude oil desulfurisation: sulfur compounds removed during distillation
-Flue-gas desulfurisation: coal crushed and washed away, leaving solid
-Dry flue-gas desulfurisation: SO2 reacts with calcium carbonate, produces solid
-Wet flue-gas desulfurisation: sodium hydrogen sulfite, then sodium sulfite - 6Control of oxides of nitrogen-Low-temperature combustion: less NOx produced using fluidised bed combustion so increase surface area, more rapid combustion
-Catalytic converters: exhaust pipes contain a catalyst which chemically reduces NOX to nitrogen and oxygen
-Urea sprays remove NOx as they react with urea producing nitrogen, CO2 and water
Informações
- Descrição
- A level Environmental Studies FlashCards sobre Acid Rain, criado por Mollie Munday em 14-02-2019.
- Criado por
- Mollie Munday · fev 2019
- Atualizado
- 20 fev 2019
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