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  2. Streeter–Phelps equation - Wikipedia

    en.wikipedia.org/wiki/Streeter–Phelps_equation

    The Streeter–Phelps equation is used in the study of water pollution as a water quality modelling tool. The model describes how dissolved oxygen (DO) decreases in a river or stream along a certain distance by degradation of biochemical oxygen demand (BOD).

  3. Water retention curve - Wikipedia

    en.wikipedia.org/wiki/Water_retention_curve

    Water retention curve is the relationship between the water content, θ, and the soil water potential, ψ. The soil moisture curve is characteristic for different types of soil, and is also called the soil moisture characteristic. It is used to predict the soil water storage, water supply to the plants (field capacity) and soil aggregate stability.

  4. Partition coefficient - Wikipedia

    en.wikipedia.org/wiki/Partition_coefficient

    It is also frequently referred to by the symbol P, especially in the English literature. It is also known as n-octanol-water partition ratio. [63] [64] [65] K ow, being a type of partition coefficient, serves as a measure of the relationship between lipophilicity (fat solubility) and hydrophilicity (water solubility) of a substance. The value ...

  5. Octanol-water partition coefficient - Wikipedia

    en.wikipedia.org/wiki/Octanol-water_partition...

    It is also called n-octanol-water partition ratio. [2] [3] [4] K ow serves as a measure of the relationship between lipophilicity (fat solubility) and hydrophilicity (water solubility) of a substance. The value is greater than one if a substance is more soluble in fat-like solvents such as n-octanol, and less than one if it is more soluble in ...

  6. Heptane - Wikipedia

    en.wikipedia.org/wiki/Heptane

    Heptane or n-heptane is the straight-chain alkane with the chemical formula H 3 C(CH 2) 5 CH 3 or C 7 H 16. When used as a test fuel component in anti-knock test engines, a 100% heptane fuel is the zero point of the octane rating scale (the 100 point is 100% iso-octane ).

  7. Winkler titration - Wikipedia

    en.wikipedia.org/wiki/Winkler_titration

    The Winkler test is used to determine the concentration of dissolved oxygen in water samples. Dissolved oxygen (D.O.) is widely used in water quality studies and routine operation of water reclamation facilities to analyze its level of oxygen saturation. In the test, an excess of manganese(II) salt, iodide (I −) and hydroxide (OH −) ions ...

  8. Redox gradient - Wikipedia

    en.wikipedia.org/wiki/Redox_gradient

    With time, the starting E h of a soil can be restored as water drains and the soil dries out. [1] [8] Soils with redox gradients formed by ascending groundwater are classified as gleysols, while soils with gradients formed by stagnant water are classified as stagnosols and planosols. Soil E h generally ranges from −300 to +900 mV. [8]

  9. Oxygen saturation - Wikipedia

    en.wikipedia.org/wiki/Oxygen_saturation

    Dissolved oxygen levels required by various species in the Chesapeake Bay (US). In aquatic environments, oxygen saturation is a ratio of the concentration of "dissolved oxygen" (DO, O 2), to the maximum amount of oxygen that will dissolve in that water body, at the temperature and pressure which constitute stable equilibrium conditions.