Wastewater Testing Equations

  • Sample volume

    1,000,000 ppm

    X

    Known Chemical ppm

    =

    HOW MUCH TO ADD TO SAMPLE

    Ex

    500 ml

    1,000,000 ppm

    =

    0.0005 x 1,000 ppm (6016)

    =

    0.5 ml of 6016
    added to jar test

  • Amount of chemical added to sample

    Sample volume

    X

    1,000,000 ppm

    =

    PPM OF CHEMICAL ADDED

    Ex

    2 ml (6016)

    500 ml water

    =

    0.004 x 1,000,000 ppm

    =

    4,000 ppm (6016)

Converting PPM to GPH:

  • (Plant flow rate in GPM x 60 min)

    1,000,000 ppm

    X

    desired chemical ppm

    =

    CHEMICAL FEED RATE

    Ex

    25 GPM x 60 min

    =

    1500 GPH

    1,000,000 ppm

    =

    0.0015 x 4,000 ppm (6016)

    =

    6 GPH (6016

Adjusting chemical pumps to desired feed rate:

  • Pump max feed rate (GPD)

    24 hours

    =

    MAX FEED RATE

    Ex

    85 GPD

    24 hours

    =

    3.54 GPH
    (feed rate)

Use previous equation to determine chemical feed rate (GPH)

  • Ex

    25 GPM x 60 min

    =

    1500 GPH

    1,000,000 ppm

    =

    0.0015

    0.0015 x 2,000 GPH
    (6016 desired flow rate)

    =

    3 GPH

    Needed feed rate

    Max pump feed rate

    =

    3 GPH

    3.54 GPH

    =

    85% (set pump at 85% of max feed rate)

Dilution factor (mostly for floc)

  • Day tank floc volume

    Volume of water added

    =

    % Product

    Ex

    10 gal (300 L)

    100 gal water

    =

    10%

Keep in mind when you decide on a needed chemical feed, you must divide the PPM by the dilution factor.

  • 300 ppm (desired 300 L)

    0.1

    =

    3000 ppm
    feed rate