From Ecopedia

Overview

Discovered in 1773 by Carl Wilhelm Scheele, oxygen (O2) is an essential life-giving element found most abundantly in the crust of our planet. After hydrogen and helium, oxygen occurs in abundance in the universe. Scientists believe that oxygen is the byproduct of photosynthesis in plants, which converts sunlight into energy.

At standard temperatures and pressure, oxygen is in a diatomic state, constituting 20.9% of the air volume. Organic compounds such as carbohydrates, proteins and fats and inorganic compounds including animal shells, bone, teeth and animal fats contain varied amounts of oxygen. Oxygen is a necessary component to all living organisms.

Oxygen can also be industrially produced through liquefied air fractional distillation process, which involves separation of nitrogen and carbon dioxide (CO2) from air, water and other means. It is extensively used in the production of plastics, steel, textiles and plastics as well as submarines and aircraft.^[1] Although it can be produced industrially, Concentrated oxygen sources tend to promote rapid oxygen combustion leading to the hazardous fuel-propelled fires and explosions.^[2]

Environmental Information

Deforestation

Because free oxygen is produced by the light splitting of water during photosynthesis, many environmentalists fear that deforestation and climate change can have a vast affect on the amount of oxygen in the atmosphere. If trees are consistently chopped and rainforests cleared, and climate change affects the habitats in which plants flourish, then depletion of oxygen may in fact be the case.^[3]

Ozone

Ozone (O3), an important allotrope of oxygen, forms a high-altitude atmospheric layer, which aids in protecting the biosphere of the earth from the harmful ultraviolet radiation of the sun.^[4] However, near the surface, ozone is released as a by-product of smog, causing air pollution.

Oxygen Depletion

Among the many effects of oxygen on the environment, oxygen depletion (hypoxia) is considered to be the most hazardous and most fatal.

Hypoxia, occurring in aquatic environments, is caused due to reduced concentrations of dissolved oxygen in the water bodies. Hypoxia is highly detrimental to the existence of aquatic organisms including fish, jelly fish and phytoplankton among many others.

Pollution and eutrophication, a condition in which nutrients of plants enter rivers, lakes or oceans and encourage phytoplankton blooms, are major causes for oxygen depletion in water bodies.

Prolonged water contamination due to inadequate waste water treatment, leaching of fertilizers, phosphorous, nitrogen and other chemicals into the waters, causes irreparable damage to the aquatic life, endangering the existence of freshwater shrimp and other aquatic organisms.^[5]

Various industrial effluents, containing toxic material, also promote oxygen depletion. Soluble organic compounds and suspended solids, constituting the industrial effluents, undergo progressive decay resulting in severe depletion of oxygen, besides precipitating different noxious gases into the atmosphere.^[6]

References

1. ↑ http://en.wikipedia.org/wiki/Oxygen
2. ↑ http://www.lenntech.com/periodic/elements/o.htm
3. ↑ http://en.wikipedia.org/wiki/Oxygen#Photosynthesis_and_respiration
4. ↑ http://en.wikipedia.org/wiki/Oxygen
5. ↑ http://en.wikipedia.org/wiki/Hypoxia_(environmental)
6. ↑ http://www.molecular-plant-biotechnology.info/biotechnology-environments/pollution-control/reducing-environmental-impact-of-industrial-effluents.html