Dissolved oxygen analysis measures the amount of gaseous oxygen (O2) dissolved in an aqueous solution. Oxygen gets into water by diffusion from the surrounding air, by aeration (rapid movement), and as a waste product of photosynthesis. Whe...
http://www.state.ky.us/nrepc/water/wcpdo.htm
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The main factor contributing to changes in dissolved oxygen levels is the build-up of organic wastes. Decay of organic wastes consumes oxygen and is often concentrated in summer, when aquatic animals require more oxygen to support higher metabolisms.
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www.fivecreeks.org/monitor/do.html
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Fish growth and activity usually require 5-6 ppm of dissolved oxygen. Dissolved oxygen levels below 3 ppm are stressful to most aquatic organisms. Levels below 2 ppm will not support fish at all.
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www.cotf.edu/ete/modules/waterq3/WQassess3f.html
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Biological Advantages of the oxygen dissolvec in water ... As dissolved oxygen levels in water drop below 5.0 mg/l, aquatic life is put under stress. The lower the concentration, the greater the stress. Oxygen levels that remain below 1-2 mg/l for a few hours can result in large fish kills.
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www.lenntech.com/why_the_oxygen_dissolved_is_important....
www.lenntech.com/why_the_oxygen_dissolved_is_important.htm
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Dissolved oxygen levels rose by 5 +/- 2 vol.%. The pH increased by 0.04 +/- 0.01. CONCLUSIONS: The temperature change was attributed mainly to evaporation of fluid in the collection tube. Changes in dissolved oxygen levels and pH were due to contact with air.
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www.medscape.com/medline/abstract/16538552
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Dissolved oxygen levels in the fermentation medium were measured with a membrane-type electrode. Peak yields of asparaginase were obtained in unbaffled flasks (3.0 to 3.8 IU/ml) and in the fermentor (2.7 IU/ml) when the level of dissolved oxygen in the culture medium reached zero.
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www.medscape.com/medline/abstract/4912278
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An oxygen depletion event can be predicted and, therefore, prevented by monitoring dissolved oxygen levels in a pond. The most efficient tool for measuring DO is an electronic oxygen meter. These instruments are available through most aquaculture supply companies at a variety of prices.
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Decreases in the dissolved oxygen levels can cause changes in the types and numbers of aquatic macroinvertebrates which live in a water ecosystem. Species which cannot tolerate decreases in dissolved oxygen levels include mayfly nymphs, stonefly nymphs, caddisfly larvae and beetle larvae.
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www.ncsu.edu/sciencejunction/depot/experiments/water/le...
www.ncsu.edu/sciencejunction/depot/experiments/water/lessons/do/
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As dissolved oxygen levels in water drop below 5.0 mg/L, aquatic life is put under stress. The lower the concentration, the greater the stress. Oxygen levels that remain below 1-2 mg/L for a few hours can result in large fish kills.
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kywater.org/ww/ramp/rmdo2.htm
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