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Topic: Dissolved oxygen


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  OMEGA ENGINEERING - Technical Dissolved Oxygen
Dissolved oxygen (DO) is the term commonly used in liquid analytical work for the measurement of the amount of oxygen dissolved in a unit volume of water.
Although dissolved organic materials are not known to interface with the output from dissolved oxygen probes, inorganic salts are a factor in the performance of the probes.
At the surface of the electrode the thallous-ion concentration is proportional to the dissolved oxygen.
www.omega.com /techref/ph-1.html   (1689 words)

  
 Dissolved Oxygen
Dissolved oxygen is probably the single most important water quality factor that pond managers need to understand.
Most oxygen deletions occur in the summer months because 1) warm water holds less dissolved oxygen than cool or cold water, and 2) because the pond's oxygen demand is greater in warm water than in cold water.
Plankton die-offs cause rapid oxygen depletions for two reasons: 1) the remaining dissolved oxygen is consumed by aerobic bacteria and fungi in the process of decaying the dead algae and 2) few live phytoplankton remain to produce more oxygen.
aquaplant.tamu.edu /contents/dissolved_oxygen.htm   (1112 words)

  
 Lake Access -- Dissolved Oxygen in Lakes
Oxygen concentrations are much higher in air, which is about 21% oxygen, than in water, which is a tiny fraction of 1 percent oxygen.
Dissolved oxygen concentrations are most often reported in units of milligrams of gas per liter of water - mg/L. (The unit mg/L is equivalent to parts per million = ppm).
Oxygen saturation is calculated as the percentage of dissolved O2 concentration relative to that when completely saturated at the temperature of the measurement depth.
lakeaccess.org /russ/oxygen.htm   (1173 words)

  
 Science Junction - Water What Ifs - Dissolved Oxygen Lessons
The oxygen is used by plants and animals for respiration and by the aerobic bacteria which consume oxygen during the process of decomposition.
When organic matter such as animal waste or improperly treated wastewater enters a body of water, algae growth increases and the dissolved oxygen levels decrease as the plant material dies off and is decomposed through the action of the aerobic bacteria.
Dissolved Oxygen Lessons 1, 2, and 3 are intended for middle school and high school science students.
www.ncsu.edu /sciencejunction/depot/experiments/water/lessons/do   (451 words)

  
 Dissolved Oxygen   (Site not responding. Last check: 2007-11-05)
Oxygen dissolves in water mainly by two methods: directly from the atmosphere and as a by-product from plant photosynthesis.
Oxygen enters the water by photosynthesis of aquatic biota and by the transfer of oxygen across the air-water interface.
Dissolved oxygen may play a large role in the survival of biota in temperate lakes and reservoirs during the summer months, due to a phenomenon called stratification.
www.telwf.org /watertesting/dissolvedoxygen.htm   (869 words)

  
 Resources - What is Dissolved Oxygen?
All animals need oxygen to live; dissolved oxygen in water is as important to animals living in water as the oxygen in air is important to animals living on land.
Dissolved oxygen gets into water in the same way that water gets into air; oxygen is a byproduct of photosynthesis, whether photosynthesis occurs underwater or in air.
This means that dissolved oxygen varies through the course of the day, and along a stream where the stream moves in and out of sunlight areas.
octopus.gma.org /vital_signs/resources/dissolved_oxygen.asp   (403 words)

  
 Dissolved Oxygen Test   (Site not responding. Last check: 2007-11-05)
Dissolved oxygen levels rise from morning through the afternoon as a result of photosynthesis, reaching a peak in late afternoon.
The percent saturation of water with dissolved oxygen at a given temperature is determined by pairing temperature of the water with the dissolved oxygen value, after first correcting your dissolved oxygen measurement for the effects of atmospheric pressure.
Rivers that consistently have a dissolved oxygen value of 90 percent or higher are considered healthy, unless the waters are supersaturated due to cultural eutrophication.
www.bradwoods.org /eagles/dot.htm   (1648 words)

  
 WDNR - Oxygen - Understanding Lake Data
Oxygen (O2) is undoubtedly the most important of the gases, since most aquatic organisms need it to survive.
Low oxygen levels in the hypolimnion mean that fish must live in the epilimnion and metalimnion.
This is the minimum amount of oxygen needed for fish to survive and grow.
www.dnr.state.wi.us /org/water/fhp/lakes/under/oxygen.htm   (594 words)

  
 Stream Dissolved Oxygen - Chapter 3 - Streams in A Citizen's Guide to Understanding and Monitoring Lakes and Streams   (Site not responding. Last check: 2007-11-05)
Dissolved oxygen concentrations increase wherever the water flow becomes turbulent, such as in a riffle area, waterfall, or a dam.
Oxygen concentrations are much higher in air, which is about 21 percent oxygen, than in water, which is a tiny fraction of 1 percent oxygen.
Dissolved oxygen concentrations are reported in units of milligrams of gas per liter of water (mg/L).
www.ecy.wa.gov /programs/wq/plants/management/joysmanual/streamdo.html   (845 words)

  
 BASIN: General Information on Dissolved Oxygen
The amount of oxygen dissolved in water is expressed as a concentration, in milligrams per liter (mg/l) of water.
Dissolved oxygen levels are also often reported in percent saturation.
During rainy seasons, oxygen concentrations tend to be higher because the rain interacts with oxygen in the air as it falls.
bcn.boulder.co.us /basin/data/COBWQ/info/DO.html   (1691 words)

  
 Dissolved Oxygen..
Oxygen is produced during the day when sunlight shines on the plants in the water.
An oxygen depletion severe enough to result in significant fish mortality is often observed in water with heavy populations of algae or aquatic plants.
Dissolved oxygen concentrations below 5 mg/L may be harmful to fish, and piping (gulping air at the surface) may be observed when DO falls below 2 mg/L. Low levels of DO are most frequently associated with hot, cloudy weather, algae die-offs, or heavy thunderstorms.
article.dphnet.com /cat-02/oxygen1.shtml   (1333 words)

  
 Dissolved Oxygen - The Global Water Sampling Project   (Site not responding. Last check: 2007-11-05)
Some of the dissolved oxygen in the water is a result of photosynthesis of aquatic plants.
Dissolved oxygen levels are often measured in parts per million (ppm) but sometimes are given in terms of Percent Saturation.
Percent Saturation is the amount of oxygen dissolved in the water sample compared to the maximum amount that could be present at the same temperature.
www.k12science.org /curriculum/waterproj/oxygen.shtml   (723 words)

  
 dissolved oxygen   (Site not responding. Last check: 2007-11-05)
Oxygen is a limiting factor throughout the life cycle of salmonids.
The optimum level of dissolved oxygen at which salmonids thrive is seven to ten parts per million (7 - 10 ppm).
There are many habitat factors which influence and impact the amount of dissolved oxygen in the stream.
www.steponline.info /lessons/disox.html   (309 words)

  
 EPA > OWOW > Monitoring and Assessing Water Quality > Volunteer Stream Monitoring: A Methods Manual > ...
Dissolved oxygen is measured primarily either by using some variation of the Winkler method or by using a meter and probe.
The rate of oxygen consumption in a stream is affected by a number of variables: temperature, pH, the presence of certain kinds of microorganisms, and the type of organic and inorganic material in the water.
One is tested immediately for dissolved oxygen, and the second is incubated in the dark at 20 C for 5 days and then tested for the amount of dissolved oxygen remaining.
www.epa.gov /owow/monitoring/volunteer/stream/vms52.html   (3714 words)

  
 EPA-MAIA - Dissolved Oxygen   (Site not responding. Last check: 2007-11-05)
Dissolved oxygen (DO) is a fundamental requirement for the maintenance of balanced populations of fish, shellfish, and other aquatic biota.
Oxygen is transferred from the atmosphere into the surface waters by diffusion and the aerating action of wind.
Dissolved oxygen (DO) is a fundamental requirement for the maintenance of balanced indigenous populations of fish, shellfish, and other aquatic biota.
www.epa.gov /emfjulte/tpmcmaia/html/oxygen.html   (547 words)

  
 Dissolved oxygen corrosion   (Site not responding. Last check: 2007-11-05)
Dissolved oxygen can destroy the protective hydrogen film that can form of many metals and oxidize dissolved ions into insoluble forms.
Dissolved oxygen (DO) refers to the volume of oxygen that is contained in water.
Thus, the amount of oxygen absorbed in water decreases as altitude increases because of the decrease in relative pressure.
www.corrosion-doctors.org /NaturalWaters/dissolvedoxygen.htm   (149 words)

  
 Dissolved Oxygen
Dissolved oxygen is taken in by aquatic life such as fish, plankton, and
For example, at 25 degrees Celsius dissolved oxygen solubility is 8.3 mg/L, whereas at 4 degrees the solubility is 13.1 mg/L. Dissolved oxygen levels can vary not only with different water temperatures, but also with the rate of flow, water depth, altitude and seasonal and daily cycles.
Too much dissolved oxygen is never a problem in naturally flowing streams but it can be a problem in streams that have been altered by humans.
www.mellen.k12.wi.us /science/water_studies/dissolved_oxygen.htm   (338 words)

  
 Dissolved Oxygen
Dissolved oxygen (DO) concentrations are expressed as milligrams of oxygen per liter of water (mg/L).
BOD is the amount of oxygen consumed by microbial decomposition of organic waste, and is measured by the change in DO in a sealed water sample over a five-day incubation period.
Streams in the Fox River Basin typically have dissolved oxygen values between 2 and 14 mg/L. The State of Wisconsin has set a minimum water quality standard of 5 mg/L DO as necessary for a stream to support fish and aquatic life.
www.uwgb.edu /watershed/data/monitoring/oxygen.htm   (512 words)

  
 Dissolved Oxygen   (Site not responding. Last check: 2007-11-05)
Dissolved oxygen (DO) is the amount of oxygen that is dissolved in water and is essential to healthy streams and lakes.
If dissolved oxygen levels are too low, some fish and other organisms may not be able to survive (see macroinvertebrates).
Dissolved oxygen levels typically can vary from 0 - 18 parts per million (ppm) although most rivers and streams require a minimum of 5 - 6 ppm to support a diverse aquatic life.
www.k12science.org /curriculum/dipproj2/en/fieldbook/oxygen.shtml   (644 words)

  
 Dissolved Oxygen
Oxygen enters the stream from the atmosphere and from photosynthesis by plants and algae.
Oxygen stress (not enough oxygen to support certain species) typically occurs in the early-morning hours during the summer months.
DO is lower during this time because of high summer water temperatures, and the oxygen demand of plants and algae that have been consuming oxygen during the night.
www.spi-ind.com /Our_Forests/Dissolved_Oxygen.htm   (140 words)

  
 SBE 43 datasheet
Oxygen features are more precisely resolved, and the agreement in down-and-up profiles reduces the ambiguity about which should be locked to bottle Winklers.
Hysteresis in oxygen measurements is caused by delays in a sensor’s response to changing temperature, pressure — and oxygen.
Even when oxygen concentration is constant, the normal range of ocean temperatures causes the output of earlier sensors to vary by a factor of two.
www.seabird.com /products/spec_sheets/43data.htm   (588 words)

  
 Dissolved Oxygen
The ratio of the dissolved oxygen content (ppm) to the potential capacity (ppm) gives the percent saturation, which is an indicator of water quality.
Please note that the dissolved oxygen sample is not taken with a Kemmerer sampler or any other, but rather with an open bottle, due to water depth at the sampling site.
In order to convert dissolved oxygen in parts per million (ppm) to percent saturation (%sat), the water temperature and barometric pressure or altitude are needed.
www.fivecreeks.org /monitor/do.html   (953 words)

  
 Fact Sheet - Dissolved Oxygen (DO)
DO is usually expressed as a concentration of oxygen in a volume of water (milligrams of oxygen per liter of water, or mg/L).
Oxygen is also introduced into water by green aquatic plants and algae during photosynthesis.
Graph of dissolved oxygen (DO; mg/L) for the Red River in the Fargo-Moorhead metro area for the period January 2001 to July 2003 in relation to the level of DO (less than 5 mg/L; red band) stressful to aquatic life.
www.eerc.und.nodak.edu /watman/FMRiver/PPTV/dissolvedoxygen.asp   (347 words)

  
 Greenwich Bay: Dissolved Oxygen   (Site not responding. Last check: 2007-11-05)
The oxygen in the water is a dissolved gas.
A familiar example of a gas dissolved in a liquid is carbon dioxide dissolved in soda.
Prolonged exposure to low dissolved oxygen levels (less than 5 mg/l) may not directly kill an animal, but may make it weak, so that can be harmed by other stress factors in the environment.
seagrant.gso.uri.edu /G_Bay/Ecosystem/DO.html   (334 words)

  
 Dissolved Oxygen
For oxygen, the approximate saturation level at 50° F. is 11.5 mg/l, at 70° F., 9 mg/l, and at 90° F., 7.5 mg/l.
Oxygen is continually transferred into the water at the surface of the pond and normally only a small water fall will bring the pond water to or near to saturation.
Almost all of the oxygen dissolved into the water from an air bubble occurs when the bubble is being formed.
www.vcnet.com /koi_net/do.html   (1660 words)

  
 Dissolved Oxygen Meters
The Dissolved Oxygen Meters have a large LCD screen that simultaneously displays oxygen and temperature.
The dissolved oxygen meters automatically temperature compensates from 0 to 50°C via a temperature probe built into the polarographic dissolved oxygen probes.
The Dissolved Oxygen meter’s display also shows a low battery indication as well as allows for maximum, minimum, and average data recall, data holding with an automatic power off feature.
www.globalw.com /products/407510.html   (439 words)

  
 Dissolved Oxygen and Water Quality   (Site not responding. Last check: 2007-11-05)
Dissolved oxygen analysis measures the amount of gaseous oxygen (O2) dissolved in an aqueous solution.
When performing the dissolved oxygen test, only grab samples should be used, and the analysis should be performed immediately.
Oxygen is a necessary element to all forms of life.
www.state.ky.us /nrepc/water/wcpdo.htm   (244 words)

  
 Dissolved Oxygen(Lake Whatcom Management Program)
Dissolved Oxygen (DO) is the amount of oxygen dissolved in water.
Oxygen enters the water by absorption directly from the atmosphere or by aquatic plant and algae photosynthesis.
Oxygen is removed from the water through animal respiration and decomposition of organic matter.
lakewhatcom.wsu.edu /display.asp?ID=36   (487 words)

  
 CSERD Resources: Activities: Dissolved Oxygen Activity
The oxygen is used by fish and other animals in the water to "breath" through their gills or other respiratory systems and by plants.
The level of oxygen dissolved in the water is inversely related to the water temperature.
Because of the molecular weight of water, ppm of dissolved substances in water is also equivalent to milligrams of the substance per liter of water.
www.shodor.org /refdesk/Resources/Activities/DissolvedOxygen   (1254 words)

  
 DO Theory
Additionally, biochemical oxygen demand (BOD) is commonly used with reference to effluent discharges and is a common, environmental procedure for determining the extent to which oxygen within a sample can support microbial life.
For dissolved oxygen measurements with EID meter and/or logger, one of the points on the line is the zero point of the sensor.
The equation for the dissolved oxygen concentration illustrates that the predicted concentration is a function of sample temperature because K
www.eidusa.com /Theory_DO.htm   (2654 words)

  
 Water Analysis-Dissolved Oxygen
Oxygen is vital to the life cycle common to water.
Oxygen is soluble in water in direct proportion to the partial pressure in the gas phase and solubility decreases as temperature increases.
Oxygen enters the water by absorption directly from the atmosphere or by plant photosynthesis.
www.adbio.com /science/analysis/do.htm   (616 words)

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