Air Quality Analyses
1. Redox reactions in the atmosphere are very important in that they influence the concentration and effects of many organic and inorganic air pollutants. To start with the atmosphere is usually thermodynamically oxidizing due to the 21% concentration of oxygen. One redox reaction that occurs in the atmosphere is rusting. This particularly occurs in iron. This due to exposure to moist air this is a redox reaction. According to Environmental chemistry by Barlam Pani, anthropogenic and natural sources discharge compounds containing carbon, nitrogen and sulphur in reduced or partially oxidized states. Due to the oxidising nature of the atmosphere these reduced compounds are oxidised. For example the reduced carbon in hydrocarbon is oxidised to form oxygenated organic molecules called aldehydes then carbon monoxide and into carbon dioxide. Nitrogen monoxide is oxidised into nitrogen dioxide which reacts with the atmospheric moisture to form nitric acid and in the case of sulphur form sulphuric acid which is precipitated as acidic rain. These oxidized products also form photochemical smog.
2. Particle size is very important in air chemistry in determining thermal radiation. Particles suspended in the atmosphere absorb and scatter radiation. The process is highly dependent on the size of the particles. The size of these particles may be in the form of mass, volume and surface area. These particle sizes are important in determining thermal radiation penetration in that, small sized particles with either small mass, or volume are likely to be easier to penetrate by thermal radiation as compared to larger sized particles. In this case, the particle size is smaller as compared to its wavelength. Large particles, whose size is comparable to the wavelength of visible light, play an important role in determining the atmospheric visibility.
REFERENCES
– Atmospheric Chemistry – E Meszaros
– Textbook of Environmental Chemistry- Balram Pani.
– Godish, T., Davis, W., & Fu, J (2015). Air quality (5th Ed.) Boca Raton, FL: CRC press.
===>
Study Notes:
Redox reactions, or oxidation-reduction reactions, are crucial in controlling the atmospheric concentrations of various pollutants. In the atmosphere, redox reactions help to break down and remove harmful pollutants such as ozone, nitrogen oxides, and volatile organic compounds. They also play a role in determining the levels of air pollutants like sulfur dioxide, which is produced from the burning of fossil fuels and can cause respiratory problems and acid rain. Additionally, redox reactions can alter the chemical form and behavior of pollutants, making them more or less harmful to human health and the environment. Furthermore, redox reactions can also affect the lifetimes of atmospheric pollutants, influencing their atmospheric transport and distribution, as well as their environmental impacts. Overall, redox reactions play a significant role in shaping the atmospheric concentrations and effects of many organic and inorganic pollutants, making them an important area of study for air quality and environmental scientists.
