Archive for the ‘BOD’ Category

Advantages of Aerobic over Anaerobic Digestion

The major advantages of aerobic digestion over anaerobic digestion are:


  • Volatile solids reduction meets or exceeds that of anaerobic digestion.
  • The stabilized sludge is free of offensive odor and an excellent fertilizer.
  • Supernatant BOD concentrations are lower than that of anaerobic digestion.
  • Operation is relatively easy.

aerobic digestion

The major disadvantage of aerobic digestion is the cost of supplying oxygen to [....]


Things that can cause toxicity include many of the following:
     Metals: lead, antimony, copper, zinc, chromium, cadmium, nickel, manganese
(permanganate), sliver,
    Oxidizers: chlorine, chloramines, any of the group VII compounds in the
periodic table, permanganates, ozone, fluorine, iodine, peroxides, and
so on.
             All of these compounds are direct toxins, because they directly interfere
with the biological [....]

Calculation of Chemical Oxygen Demand (C.O.D)

Calculation of Chemical Oxygen Demand (C.O.D)


Round bottom flask, water condenser, Burette, Pipette,Heating mantle.


* Mercuric sulphate (< 1gm)

* Sulfuric Acid (1 Kg H2SO4 + 5.5 gm Ag2SO4 ) dissolve for 24 hrs.

* 0.25 N Potassium Dichromate (12.259 gm K2Cr2O7 dried at [....]

Food-to-Microorganism Ratio(F/M Ratio)

Food-to-Microorganism ratio (F/M ratio)

The food-to-microorganism ratio (F/M ratio) is a process control method/calculation based upon maintaining a specified balance between available food materials (BOD or COD) in the aeration tank influent and the aeration tank mixed liquor volatile suspended solids (MLVSS) concentration The chemical oxygen demand test is sometimes used, because the results are available in a relatively short [....]

BOD/COD Loading on Aeration Process

Calculating BOD, COD, or SS loading on an aeration process

When calculating COD, BOD, or SS loading on an aeration process (or any other treatment process),loading on the process is usually calculated as lb/day. The following equation is used:
BOD, COD, or SS loading (lb/day) = mg/L x MGD x 8.34 lb/gal


The BOD concentration of the wastewater [....]

Determination of Bio-Chemical Oxygen Demand (B.O.D)


* Incubator

* Stoppard Bottles

* Burette

* Pipette

* Conical flask

Chemicals: Reagents

* MnSO4 soln (364 gm MnSO4.H2O + 1 ltr boiling D.W.)

* CaCl2 soln. (27.5gm anhydrous CaCl2 + 1 Ltr D.W.)

* FeCl3 soln. (0.25gm FeCl3.6H2O + 1 Ltr D.W.)

* Phosphate Buffer [....]