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  2. Biochemical oxygen demand - Wikipedia

    en.wikipedia.org/wiki/Biochemical_oxygen_demand

    BOD test bottles at the laboratory of a wastewater treatment plant. Biochemical oxygen demand (also known as BOD or biological oxygen demand) is an analytical parameter representing the amount of dissolved oxygen (DO) consumed by aerobic bacteria growing on the organic material present in a water sample at a specific temperature over a specific time period.

  3. Infiltration (hydrology) - Wikipedia

    en.wikipedia.org/wiki/Infiltration_(hydrology)

    One exception to this rule is when the clay is present in dry conditions. In this case, the soil can develop large cracks which lead to higher infiltration capacity. [3] Soil compaction also impacts infiltration capacity. Compaction of soils results in decreased porosity within the soils, which decreases infiltration capacity. [4]

  4. Water balance - Wikipedia

    en.wikipedia.org/wiki/Water_balance

    This means that the volume of water in a WRS decreased after a decade, i.e., inflow was less than outflow during that time interval. [11] In general, a WUS is a water construct of a user, such as a city, an industry, an irrigation zone, or a region, and not a geographic area. The schematic of a WUS shows the inflows and the outflows.

  5. 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. The ...

  6. Infiltration/Inflow - Wikipedia

    en.wikipedia.org/wiki/Infiltration/Inflow

    Infiltration/Inflow (I/I or I&I) is the process of groundwater, or water from sources other than domestic wastewater, entering sanitary sewers. I/I causes dilution in sanitary sewers, which decreases the efficiency of treatment, and may cause sewage volumes to exceed design capacity.

  7. Richards equation - Wikipedia

    en.wikipedia.org/wiki/Richards_equation

    The Richards equation represents the movement of water in unsaturated soils, and is attributed to Lorenzo A. Richards who published the equation in 1931. [1] It is a quasilinear partial differential equation; its analytical solution is often limited to specific initial and boundary conditions. [2]

  8. Drainage equation - Wikipedia

    en.wikipedia.org/wiki/Drainage_equation

    the soil's hydraulic conductivity (Ka and Kb) by measurements; the depth of the bottom of the aquifer (Di) the design drain spacing (L) can be found from the equation in dependence of the drain depth (Dd) and drain radius (r). Drainage criteria

  9. Assimilative capacity - Wikipedia

    en.wikipedia.org/wiki/Assimilative_capacity

    Assimilative capacity is the ability for pollutants to be absorbed by an environment without detrimental effects to the environment or those who use of it. [1] Natural absorption into an environment is achieved through dilution, dispersion and removal through chemical or biological processes. [1]