h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Entry: The Impact of the Internal Combustion Engine on the Urban Environment - A3421289
Author: TRiG (Ireland) No sugar in mine, love. - U612575

I'm posting this, my first foray into Peer Review, just before going on holiday. It's unlikely that I'll have internet access while I'm away. I'll be back in mid-January to take account of any suggestions made.

Christmas reading for Peerers eh TRiG?

I'll be back

Very good - you'll get no arguements from me - but I'm taking your word for the chemistry.

Hmm. First thougghts:

1.I would change the title to something like,"Impact of the I/C Engine on Atmospheric Pollution'. Then you could miss out a lot of the explanatory blurb in the first paragraph.

2. Ref. . I think you need to insert that motor fuel are obtained from crude oil produced by the decay of marine organisms. Having once been living, they were made up of proteins which are organic compounds containing the elements C, H, O, N. Hence motor fuel contains hydrocarbons and organic compounds containing nitrogen. When these are burned burned in air the products are water, carbon monoxide, and oxides of nitrogen (NO, NO2, N2O4; collectively known as NOX). In addition, air contains 78% of nitrogen gas which, at the high temperatures present in the cylinder can also react to form NOX.The actual oxides of carbon and nitrogen formed depend on the fuel to air ratio at the point of combustion. The exhaust gases will also contain some unburned hydrocarbon.


This then means that you can dispense with your 'unbalanced equation'.

I meant that you can dispense with much of the content of paras 2 and 3 (by giving a more focused title).

Insert words added in CAPITALS. Delete the sentences in square brackets:


CO2 — carbon dioxide. This gas is naturally present in the atmosphere at low concentration (approximately 0.035%). It absorbs infrared energy and is thus a greenhouse gas, LEADING TO GLOBAL WARMING. Concentrations of CO2 in the earth’s atmosphere appear to be increasing AND could THUS have a substantial effect on the climate. [The main anthropogenic causes of the increase in CO2 concentration are the destruction of forests and the combustion of carbon-containing fuels, which would include wood and the ‘fossil fuels’]. AS A CONSUMER of the products of crude oil the I/C ENGINE contributes to the increased concentrations of CO2 in the atmosphere, BUT CAR ENGINES ARE NOT THE GREATEST PRODUCERS OF THIS POLLUTANT. The effect of this pollution is felt WORLDWIDE, NOT JUST locally,

Add things shown in CAPITALS. Delete things in square brackets:

CO — carbon monoxide. [This polluting gas can be formed by the photodissociation of CO2 to form CO and O. This reaction, however, while being a major source of CO at higher altitudes, does not occur at ground level to any great extent8.] THE INTERNAL COMBUSTION ENGINE IS THE main source of CO in cities, where it is produced by incomplete combustion of fuel. Anthropogenic sources account for approximately 6% of the 0.1 ppm concentration of CO in the earth’s atmosphere GLOBALLY. [This is a global figure.] In an urban area, the concentration (and the percentage anthropogenic contribution) can be much higher. FOR EXAMPLE, during a city rush hour, concentrations of CO can reach 50 or even 100 ppm, which is well above the safe level9. CO is highly toxic.(INSERT explanation of why CO is toxic - combines with Hb in blood etc, etc)

CO can be oxidized to the far less harmful CO2 if there is enough O2 available. At higher air-fuel ratios the level of CO emission goes down. The fuel has undergone complete, or more nearly complete, combustion. [Most modern cars contain catalytic converters WHERE EXHAUST GASES and added air pass over a catalyst TO BE broken down to less harmful products. CO is one of the compounds whose concentration is reduced by a catalytic converter (it being oxidized to CO2). (I have suggested deleting this section in favour of including an additional Subheader entitled CATALYTIC CONVERTERS,M to include how it treats NOX)

Remove the relevant parts that are currently under 'Nitrogen' and Hydrocarbons' and place them under the aforementiomned new Subheader of 'Catalytic Converters'

INSERT sectrions shown in CAPITALS and delete things shown in square brackets:

SO2 — Sulphur dioxide. [Sulphur is more prevalent in solid fuel than in liquid] AS FOSSIL FUELS ARE DERIVED FROM ONCE LIVING ORGANISMS WHOSE PROTEINS CONTAIN A PROPRTION OF SULPHUR-CONTAINING AMINO ACIDS, UNDER COMBUSTION THIS SULPHUR REACTS WITH OXYGEN TO FORM SULPHUR DIOXIDE. HENCE some sulphur dioxide emission does occur from cars. SO2 is an acidic pollutant WHICH DISSOLVES IN MOISTURE IN THE ATMOSPHERE TO FORM SULPHUROUS AND SULPHURIC ACIDS. These cause WEATHERING of limestone buildings AND STATUARY and CORROSION OF metal surfaces. In humans, it irritates the eyes, the mucous membranes, and the respiratory tract, along with the skin in general14. SO2 also has the effect of slowing down the movements of the cilia — the hairs in the trachea which act to prevent dust’s entering the lungs —, thus exacerbating the irritation caused by allowing more pollutant to access the respiratory system.

INSERT: About acid rain mobilising aluminium ions in soil ultimately causing death of e.g. pond organisms and plants - because it would be concentrated in ponds.

SO2 is a component of ‘classical’ PHOTOCHEMICAL smog.

Some suggested links:

Carbon monoxide > A817850 (Hypoxia, CO Poisoning, Drowning)
Hydrocarbons > A834527 (Alkanes)
Alternative Fuels > A836741 (Alkanols)
Catalytic Converters > A214589

Thanks for that lot. My first day back today. Some catching up to do in other places. I'll get back to this tomorrow.

TRiG.

Hello TRiG,

Good article - very well researched if I can say so. Just a few points from a brief preview.

You have a section that talks about "Problems caused by Car Exhaust", but you only appear to list one problem - photochemical smog. You need at least 2 problems and more if possible.

Also, you don't mention the really strict standards that are in place for petrol car emissions. All new cars need to abide by standards of CO, CO2, NOx and Hydrocarbon usage which are government mandated, and will result in cars being disqualified from road usage unless they qualify. These standards are extremely strict in Germany and the UK, and most motorists in Europe are obliged to have their cars checked on a regular basis for compliance to the standards.

I think you might also discuss the role of the catalytic converters in cleaning up emission levels. Many cars can now regulate their own emissions, and will prompt warning lights to be shown if they start to breach the set limits.

Leaded petrol might also be mentioned even if just from a historical perspective. I'm not sure if leaded fuel is used anywhere now.

Woodpigeon

good article but a little heavy going.Remember every equation 1/2's your readership and a lot of people will take your word for it anyway .I had to googel 4 times in your article to understand what you where excatly saying.Intresting tho...

It was originally written as a college assignment. It shows. Some adaption may be necessary. Any specifics?

TRiG

Hiya TRiG

A few suggestions about your use of GuideML you might like to tackle.

I notice you're using lowercase letters in GuideML tags, ie. although they work, Caps. are standard for Edited Entries.

And a few places you have " double quotes, single ' quotes are standrad in Edited Entries.

Only minor details but once your Entry has reached its full potential, and begins its jouney to the front page, the time it spends with a Sub-editor is likely to be less if there's less a Sub-editer has to do, plus it makes their job easier.

Emmily

I was in the middle of editing this article (taking into account many of the suggestions made) when we had a power cut and I lost all my changes. I'll get back to it.

I've made many of the changes you suggested, radioactiveBIGAL, though usually not quite in your words. Others I haven't. I think I will, as you suggest, lump all the catalytic convertor stuff together into one section: it would probably read better that way. Also, the title could do with a change, yes. I want to keep it specific to the urban environment, though. We'll see how it goes.

Thanks for your help so far.
TRiG.

I personally prefer single quotation marks, as they are less likely to be confused for apostrophes. But here I'll have to follow the house style. I'll change them.

This was originally written as a college assignment and is therefore in a formal English style. Should I relax it? If so, where?

TRiG.

"I personally prefer single quotation marks, as they are less likely to be confused for apostrophes."

Easily done, I suppose!

TRiG.

>>>>You have a section that talks about "Problems caused by Car Exhaust", but you only appear to list one problem - photochemical smog. You need at least 2 problems and more if possible.<<<<

Acid rain is caused by the sulphur dioxide produced by cars and factories.

Alex