What causes the prescence of carbon dioxide,sulphur dioxide and nitrogen dioxides in the atmosphere?
Answers
Explanation:
it is very dangerous for us as we can die also.
because they are very harmful gas it also harmful for animals birds and plant also
Mark as brainlist!!!!
Answer:
Air Pollutants
Introduction
Air pollutants arise from a wide variety of sources, although they are mainly a result of the combustion process. The largest sources include motor vehicles and industry. The main air pollutants are reviewed according to: 1) description, 2) occurrence in air, and 3) major sources. The following units of measurement are used throughout: ppb = parts per billion; ppm = parts per million; µgm-3 = micrograms per cubic metre; mgm-3 = milligrams per cubic metre; µm = micron or micrometre (one millionth of a metre).
Oxides of Nitrogen (NOx)
NOx is a collective term used to refer to two species of oxides of nitrogen: nitric oxide (NO) and nitrogen dioxide (NO2).
Annual mean concentrations of NO2 in urban areas are generally in the range 10-45 ppb (20-90 µgm-3). Levels vary significantly throughout the day, with peaks generally occurring twice daily as a consequence of "rush hour" traffic. Maximum daily and one hourly means can be as high as 200 ppb (400 µgm-3) and 600 ppb (1200 µgm-3) respectively.
Globally, quantities of nitrogen oxides produced naturally (by bacterial and volcanic action and lightning) far outweigh anthropogenic (man-made) emissions. Anthropogenic emissions are mainly due to fossil fuel combustion from both stationary sources, i.e. power generation (21%), and mobile sources, i.e. transport (44%). Other atmospheric contributions come from non-combustion processes, for example nitric acid manufacture, welding processes and the use of explosives.
Sulphur Dioxide (SO2)
SO2 is a colourless gas. It reacts on the surface of a variety of airborne solid particles, is soluble in water and can be oxidised within airborne water droplets.
Annual mean concentrations in most major UK cities are now well below 35 ppb (100 µgm-3) with typical mean values in the range of 5-20 ppb (15-50 µgm-3). Hourly peak values can be 400-750 ppb (1000-2000 µgm-3) on infrequent occasions. Natural background levels are about 2 ppb (5 µgm-3).
The most important sources of SO2 are fossil fuel combustion, smelting, manufacture of sulphuric acid, conversion of wood pulp to paper, incineration of refuse and production of elemental sulphur. Coal burning is the single largest man-made source of SO2 accounting for about 50% of annual global emissions, with oil burning accounting for a further 25-30%.
Carbon Monoxide (CO)
Carbon Monoxide is a colourless, odourless, tasteless gas that is slightly lighter than air.
Natural background levels of CO fall in the range of 10-200 ppb. Levels in urban areas are highly variable, depending upon weather conditions and traffic density. 8-hour mean values are generally less than 10 ppm (12 mgm-3) but have been known to be as high as 500 ppm (600 mgm-3).
CO is an intermediate product through which all carbon species must pass when combusted in oxygen (O2). In the presence of an adequate supply of O2 most CO produced during combustion is immediately oxidised to carbon dioxide (CO2). However, this is not the case in spark ignition engines, especially under idling and deceleration conditions. Thus, the major source of atmospheric CO is the spark ignition combustion engine. Smaller contributions come from processes involving the combustion of organic matter, for example in power stations and waste incineration