NOx is the abbreviated form of nitrogen oxide, which refers to a group of highly reactive greenhouse gases that are compounds of nitrogen and oxygen in varying amounts. Nitric oxide (NO) and nitrogen dioxide (NO2) are two of its most important variants. These relatively inert gases are mostly colorless
and odorless, and are formed during combustion at high temperatures and at certain conditions. Main sources of NOx include motor vehicles, electric utilities, industrial plants, and residential units where fuel is burned. Agricultural soil, animal manure, sewage plants, and adipic acid are other emission sources that are human-influenced.
NOx ever since has been a major pollutant that poses serious environmental concerns. NO2 often envelops cities, together with the other air particles, in a reddish-brown fog. This can cause problems with landscape visibility. Because of the wind patterns on American geography, NOx can also be
transported to other regions where it is not emitted. The US Environmental Protection Agency (EPA) has expressed concerns about its increased emissions this past three decades for approximately 10 percent. However, all major pollutants like carbon monoxide, sulfur dioxide, lead, particulate matter, and other volatile organic compounds have decreased significantly since 1970. NOx greatly affects water quality as well. As nutrient concentrations increase, surface water breaks down and clarity is affected. Toxic chemicals are also formed in lakes and rivers that can affect aquatic life. When NOx reacts with partly-oxidized organic particles under sunlight, it forms tropospheric ozone. Increase of this ground-level ozone greatly contributes to global warming.
Aside from threatening the environment, NOx is downright damaging for health. When it forms nitrate particles and acid aerosols, it can cause respiratory problems because of lung tissue destruction. NO2 in particular is very poisonous and can be fatal in very high levels. Children and old patients are at high-risk especially.
Diesel urea or diesel exhaust fluid (DEF) is used to reduce NOx in exhaust gases from fuel combustion. After injecting the urea solution into the exhaust system, ammonia produced through urea hydrolysis reacts with NOx emissions. It will in turn convert emissions into nitrogen and water.
For more information on nitrogen oxide, visit the following:
•NOx Definition. (n.d.). Raypak: Hydronic Heating, Commercial Water Heating, Swimming Pool Heating; Spa heating, Boilers; Water Heaters. Retrieved May 24, 2011, from http://www.raypak.com/lownoxtech.htm
•Nitrogen Oxides Sources and Health Effects - WDNR. (2011, May 3). Wisconsin Department of Natural Resources. Retrieved May 24, 2011, from http://dnr.wi.gov/air/aq/pollutant/oxides.htm
•Nitrous Oxide | Climate Change . (2010, June 23). US Environmental Protection Agency. Retrieved May 24, 2011, from http://www.epa.gov/nitrousoxide/
and odorless, and are formed during combustion at high temperatures and at certain conditions. Main sources of NOx include motor vehicles, electric utilities, industrial plants, and residential units where fuel is burned. Agricultural soil, animal manure, sewage plants, and adipic acid are other emission sources that are human-influenced.
NOx ever since has been a major pollutant that poses serious environmental concerns. NO2 often envelops cities, together with the other air particles, in a reddish-brown fog. This can cause problems with landscape visibility. Because of the wind patterns on American geography, NOx can also be
transported to other regions where it is not emitted. The US Environmental Protection Agency (EPA) has expressed concerns about its increased emissions this past three decades for approximately 10 percent. However, all major pollutants like carbon monoxide, sulfur dioxide, lead, particulate matter, and other volatile organic compounds have decreased significantly since 1970. NOx greatly affects water quality as well. As nutrient concentrations increase, surface water breaks down and clarity is affected. Toxic chemicals are also formed in lakes and rivers that can affect aquatic life. When NOx reacts with partly-oxidized organic particles under sunlight, it forms tropospheric ozone. Increase of this ground-level ozone greatly contributes to global warming.
Aside from threatening the environment, NOx is downright damaging for health. When it forms nitrate particles and acid aerosols, it can cause respiratory problems because of lung tissue destruction. NO2 in particular is very poisonous and can be fatal in very high levels. Children and old patients are at high-risk especially.
Diesel urea or diesel exhaust fluid (DEF) is used to reduce NOx in exhaust gases from fuel combustion. After injecting the urea solution into the exhaust system, ammonia produced through urea hydrolysis reacts with NOx emissions. It will in turn convert emissions into nitrogen and water.
For more information on nitrogen oxide, visit the following:
•NOx Definition. (n.d.). Raypak: Hydronic Heating, Commercial Water Heating, Swimming Pool Heating; Spa heating, Boilers; Water Heaters. Retrieved May 24, 2011, from http://www.raypak.com/lownoxtech.htm
•Nitrogen Oxides Sources and Health Effects - WDNR. (2011, May 3). Wisconsin Department of Natural Resources. Retrieved May 24, 2011, from http://dnr.wi.gov/air/aq/pollutant/oxides.htm
•Nitrous Oxide | Climate Change . (2010, June 23). US Environmental Protection Agency. Retrieved May 24, 2011, from http://www.epa.gov/nitrousoxide/
