Chemical Air Pollutants & Environmental Effects

Question 1

Acid rain, its effects, and solutions

Answer 1

Acid rain: S + O2 to SO2 (which is very stable, even at high temperature, so is produced and released during combustion of fossil fuels)
2SO2 + O2 to 2 SO3 is slow
SO3 + H2O to H2SO4 is fast
Normal rain pH is 5.6 due to dissolved CO2

Effects of acid rain:

1) Acidifies the soil and can release plant nutrients and toxic metals normally bound to clay and sediments
2) Impacts sensitive species like algae then up the food train until the lake dies
3) Acidifies water and lime must be used to restore pH to lakes

Solutions:

1) Hydrogen sulphide gas can be removed but is difficult to remove from oil
2) Coal has organic or inorganic sulphur compounds present. Inorganic S is washed out by grinding and washing coal
3) Scrubbers in smoke stacks

Question 2

Suspended particulate matter (SPM)

Answer 2

Composed of solids like dust and soil that cause short term irritation to lungs and eyes, long term decreased life expectancy by a few years. Liquid SPM is sulphuric acid that causes acid rain, skin/eye irritation, and deterioration of acid sensitive materials

Question 3

Carbon monoxide (CO)

Answer 3

Comes from the incomplete combustion of fossil fuels, is a potent greenhouse gas second only to atmospheric CO2, and is colourless, odourless, and highly toxic

Question 4

Nitrogen oxides (NOx)

Answer 4

N2O is a powerful RAG, NO2 contributes to urban smog, aggravates asthma, and corrodes metals

Question 5

Hydro carbons and volatile organic compounds (VOCs)

Answer 5

A broad group of carbon based compounds that are highly volatile and produced industrially: methane (a natural gas that is an odourless, poisonous GHG), octane (found in high energy fuels like gasoline), propane, butane, xylene, benzene, formaldehyde, etc.

Question 6

Ozone at ground level

Answer 6

Is a side product of other pollutants and formed via reaction between NOx and VOCs. It is hazardous to plants/lungs and a major contributor of urban smog health effects like asthma warnings

Question 7

Sulfur oxides (SOx)

Answer 7

Is colourless, odorous, and non-flammable. These gases can travel thousands of km from their source before falling in rain.

Question 8

Photochemical smog

Answer 8

Smog results in deaths, material degradation, crop/forest damage, and other human health issues. NVOCs are very bad and include PAN, the component that irritates eyes. One potential solution would be to toss H fuel cells, from splitting water, about

Question 9

Indoor air pollutants

Answer 9

1) Tobacco smoke
2) Formaldehyde
3) Asbestos
4) Radon
5) Carbon monoxide
6) Hazardous (deadly viruses and bacteria) and annoyance (allergy causing) biologicals