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  2. Streeter–Phelps equation - Wikipedia

    en.wikipedia.org/wiki/Streeter–Phelps_equation

    The model describes how dissolved oxygen (DO) decreases in a river or stream along a certain distance by degradation of biochemical oxygen demand (BOD). The equation was derived by H. W. Streeter, a sanitary engineer, and Earle B. Phelps , a consultant for the U.S. Public Health Service , in 1925, based on field data from the Ohio River .

  3. Hypoxia (environmental) - Wikipedia

    en.wikipedia.org/wiki/Hypoxia_(environmental)

    An aquatic system lacking dissolved oxygen (0% saturation) is termed anaerobic, reducing, or anoxic. In water, oxygen levels are approximately 7 ppm or 0.0007% in good quality water, but fluctuate. [5] Many organisms require hypoxic conditions. Oxygen is poisonous to anaerobic bacteria for example. [3]

  4. Marine biogeochemical cycles - Wikipedia

    en.wikipedia.org/wiki/Marine_biogeochemical_cycles

    The word oxygen in the literature typically refers to molecular oxygen (O 2) since it is the common product or reactant of many biogeochemical redox reactions within the cycle. [37] Processes within the oxygen cycle are considered to be biological or geological and are evaluated as either a source (O 2 production) or sink (O 2 consumption). [36 ...

  5. Water aeration - Wikipedia

    en.wikipedia.org/wiki/Water_aeration

    Decreased levels of dissolved oxygen (DO) is a major contributor to poor water quality. Not only do fish and most other aquatic animals need oxygen, aerobic bacteria help decompose organic matter. When oxygen concentrations become low, anoxic conditions may develop which can decrease the ability of the water body to support life.

  6. River ecosystem - Wikipedia

    en.wikipedia.org/wiki/River_ecosystem

    The major zones in river ecosystems are determined by the river bed's gradient or by the velocity of the current. Faster moving turbulent water typically contains greater concentrations of dissolved oxygen, which supports greater biodiversity than the slow-moving water of pools

  7. Billions of years ago, the rise of oxygen in Earth’s ... - AOL

    www.aol.com/news/billions-years-ago-rise-oxygen...

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  8. Citarum River - Wikipedia

    en.wikipedia.org/wiki/Citarum_River

    The Citarum River (more correctly called the Tarum River, as the prefix "Ci" simply means "river") (Sundanese: Walungan Citarum) is the longest and largest river in West Java, Indonesia. [3] It is the third longest river in Java, after Bengawan Solo and Brantas. It plays an important role in the life of the people of West Java.

  9. Downwelling - Wikipedia

    en.wikipedia.org/wiki/Downwelling

    Buoyancy-forced downwelling, often termed convection, is the deepening of a water parcel due to a change in the density of that parcel.Density changes in the surface ocean are primarily the result of evaporation, precipitation, heating, cooling, or the introduction and mixing of an alternate water or salinity source, such as river input or brine rejection.