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  2. Parts-per notation - Wikipedia

    en.wikipedia.org/wiki/Parts-per_notation

    In science and engineering, the parts-per notation is a set of pseudo-units to describe small values of miscellaneous dimensionless quantities, e.g. mole fraction or mass fraction. Since these fractions are quantity-per-quantity measures, they are pure numbers with no associated units of measurement. Commonly used are parts-per-million (ppm, 10 ...

  3. Maximum contaminant level - Wikipedia

    en.wikipedia.org/wiki/Maximum_Contaminant_Level

    Maximum contaminant levels (MCLs) are standards that are set by the United States Environmental Protection Agency (EPA) for drinking water quality. [1][2] An MCL is the legal threshold limit on the amount of a substance that is allowed in public water systems under the Safe Drinking Water Act (SDWA). The limit is usually expressed as a ...

  4. Beer–Lambert law - Wikipedia

    en.wikipedia.org/wiki/Beer–Lambert_law

    It is often referred to as Beer's law. In physics, the Bouguer–Lambert law is an empirical law which relates the extinction or attenuation of light to the properties of the material through which the light is travelling. It had its first use in astronomical extinction. The fundamental law of extinction (the process is linear in the intensity ...

  5. Tributyl phosphate - Wikipedia

    en.wikipedia.org/wiki/Tributyl_phosphate

    227 ppm (cat, 4–5 h) 123 ppm (rat, 6 h) 117 ppm (rat) 2529 ppm (rat, 1 h) [4] LC Lo (lowest published) ... TWA 0.2 ppm (2.5 mg/m 3) [1] IDLH (Immediate danger)

  6. Clarke number - Wikipedia

    en.wikipedia.org/wiki/Clarke_number

    12 Mg magnesium: 2.50 2.50 2.24 2.11 2.08 2.08 1.940 1.940 1.93 ... [ppm], then "the clarke of concentration" of that commodity X is = (dimensionless). The value ...

  7. Abundance of elements in Earth's crust - Wikipedia

    en.wikipedia.org/wiki/Abundance_of_elements_in...

    The abundance of elements in Earth's crust is shown in tabulated form with the estimated crustal abundance for each chemical element shown as mg/kg, or parts per million (ppm) by mass (10,000 ppm = 1%).

  8. Wastewater treatment - Wikipedia

    en.wikipedia.org/wiki/Wastewater_treatment

    Wastewater treatment. Wastewater treatment is a process which removes and eliminates contaminants from wastewater. It thus converts it into an effluent that can be returned to the water cycle. Once back in the water cycle, the effluent creates an acceptable impact on the environment. It is also possible to reuse it.

  9. Solubility table - Wikipedia

    en.wikipedia.org/wiki/Solubility_table

    Substance Formula 0 °C 10 °C 20 °C 30 °C 40 °C 50 °C 60 °C 70 °C 80 °C 90 °C 100 °C Barium acetate: Ba(C 2 H 3 O 2) 2: 58.8: 62: 72: 75: 78.5: 77: 75