Category: Waste Water Calculation

Determination of Volatile Matter in Sludge

Determination of volatile matter reduction in sludge is complicated because of the changes occurring during sludge digestion.

The calculation used to determine percent volatile matter (VM) reduction is

[%VMin – %VMout] X100

% of Volatile Matter Reduction (VM)    = ——————————-

[%VMin – (%VMin X % VMout)]

Using the digester data provided below, Determine [....]

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Measurement of Sediment Oxygen Demand (SOD)

Measurement of Sediment oxygen demand (SOD) is a measure of the oxygen demand characteristics of the bottom sediment which affects the dissolved oxygen resources of the overlying water. To measure SOD, a bottom sample is especially designed to entrap and seal a known quantity of water at the river bottom. Changes in DO concentrations (approximately 2 h, or until the [....]

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How to Determine of Phosphate

Determination of Phosphate

The neutralized sample is reacted with ammonium molybdate and stannous chloride.the blue color obtained is matched against that produced with a series of standard phosphate solution, visually or with spectrophotometer at 690mu.


1.Phenolphthalein indicator solution

2.Approximately 4N sulfuric acid

3.Ammonium Molybdate Solution

4.Standard Phosphate solution


To a 50 ml.sample containing not more than 0.15mg.of phosphate(as [....]

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How to Calculate Aeration Tank Volume?

Dear reader, due to some heavy work.we couldn’t touch with u last few months, OK.

Now we see as an with small example!

Aeration tank:

Influent BOD: 250mg/l(after 30% reduction in the Physio-chemical treatment followed by primary clarifier

Process selected: Activated sludge process

Design Condition:

F/M (Food/Microbes) =0.15

MLSS (Mixed Liquor Suspended Solids)=3000 mg/l

Calculation of Aeration Tank Volume: [....]

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What is Chlorine Disinfection?


Chlorine deactivates microorganisms through several mechanisms that can destroy most biological contaminants, including: Chlorine Formula

  • Damaging the cell wall 
  • Altering the permeability of the cell (the ability to pass water in and out through the cell wall) • Altering the cell protoplasm
  • Inhibiting the enzyme activity of the cell so it is unable to use its food to produce energy
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