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Dissolved Oxygen. Andrew Stewart | Andrew Sail | Aiden Wolfe | Craig Rockwell. WHAT IS DISSOLVED OXYGEN?. Simply put, dissolved oxygen is oxygen that is dissolved in water. Eutrophication is the process of depleting levels to deadly levels. Oxygen dissolves by diffusion from surrounding air.
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Dissolved Oxygen Andrew Stewart | Andrew Sail | Aiden Wolfe | Craig Rockwell
WHAT IS DISSOLVED OXYGEN? • Simply put, dissolved oxygen is oxygen that is dissolved in water. • Eutrophication is the process of depleting levels to deadly levels. • Oxygen dissolves by diffusion from surrounding air. • Also enters water as it tumbles over cliffs and rapids. • Waste product of photosynthesis. Co2 + H2O O2 + C6H12O6
DISSOLVED OXYGEN IN NATURE • In fresh water: • Below 4 mg/L, most fish will not survive. • Between 4-10 mg/L is considered good. • Concentration above 10mg/L is excellent. • Should not exceed 110% of normal dissolved oxygen content. • Fish in water with with greater concentration may not survive due to “gas bubble disease”. Flow of blood becomes blocked. % Saturation = (DO/Saturation Level) * 100
HOW D.O. LEVELS CHANGE • Levels decrease because of water slowing down which leads to the heating of water and release of dissolved oxygen. • Levels also can be decreased by decomposition of organic matter by bacteria. • The colder the water, the higher the dissolved oxygen becomes. Winter: Higher D.O. Summer: Lower D.O.
INCREASING D.O. LEVELS • Dissolved oxygen is used up by bacteria and fungi, so filtering out microorganisms will increase dissolved oxygen levels. • Oxygen diffuses from the air into the water, so increasing surface area between air and water will increase D.O. levels. This can be done by bubbling air through the water or by constantly agitating the water.
AERATION • The process of exposing a substance to air. • i.e. Holes being poked in grass in order to promote growth. • When water is aerated, it receives dissolved oxygen.
BIBLIOGRAPHY • http://www.lenntech.com/why_the_oxygen_dissolved_is_important.htm • http://www.ky.gov/nrepc/water/wcpdo.htm • http://wordnetweb.princenton.edu/perl/webwn • http://bcn.boulder.co.us/basin/data/NEW/info/DO.html • http://www.hawaii.edu/gk-12/ev0/erinb.streams/factors.htm • http://www.sciotoswcd.org/testinfo.html • http://www.kascomarine.com/images/robust-aire-underwater-lowr.gif