|
The car is a major source of urban air pollution. At present, car engine energy conversion efficiency is about 30 percent, meaning that 70% of the energy is wasted. The energy in the form of heat with the exhaust directly into the atmosphere, and this is one of the reasons of the urban heat island effect. Look at the main component of automobile exhaust: no harmful nitrogen accounted for 72.9%, carbon dioxide accounted for 13.6 percent, accounting for 12.6% of water vapor, carbon dioxide and water vapor comes from the burning of gasoline. Another 0.12% is carbon monoxide and hydrocarbons and nitrogen oxides, carbon monoxide comes from the incomplete combustion, which also produces black smoke; hydrocarbons come from no burning gasoline or volatile; nitrogen oxides comes from high temperature and pressure combustion. In which, the last part of the percentage content is relatively less, but is has the largest impact on human health. According to some present data, when the European car is no exhaust gas catalytic, driving per km will emit 27g of CO, 12.8g the HC, 1.7g of nitrogen oxides; when using the catalyst, the corresponding per kilometer emissions: 2g of CO, 0.2g HC and 0.4g of nitrogen oxides. If not compared to health standards, we may have no perceptual knowledge of these data. In the breeze or still conditions, an exhaust without catalytic processing car, parking in the place one minute will be within three meters around the CO concentration in the air nearly 100 times more than the national standard. For automotive catalytic exhaust gas after one minute, it makes within three meters of air CO concentration nearly seven times more than GB. Automobile exhaust on the environmental impact is distinguished from long-term and short-term, CO2 is the main greenhouse gas, which has a long-term impact on global climate change; HC and nitrogen oxides will cause a short-term impact on the environment, they are produce a composite secondary pollution - photochemical smog in sunlight. The main component of photochemical smog is that ozone which has great harm to people and secondary organic aerosols, SOA due to Mie scattering effect causes visibility reduced, and form fog and haze, while SOA is very likely to be inhaled into alveolar. Read this article, I am afraid people will produce a new understanding toward car, any man-made advances are double-edged, and we are often happy to see our progress side, deliberately ignore the side of the harm or potential threat, such as genetically modified food. We enjoy today is to establish a fast and comfortable car on the basis of damage to the environment and the disregard for others’ health. Tory is always wondering where to get so many wow gold, Diablo 3 Gold and tera gold to offer the money he need in game playing. Now he found the answer and it is really useful.
Related Articles -
Who, killer, urban, air,
|
