COD – Chemical Oxygen Demand

 

 

MONOTEST COD (Chemical Oxygen Demand) kits allow to determine the needed oxygen to oxidize both organic and inorganic substances contained in water.

 

The COD can be empirically correlated with the BOD (Biochemical Oxygen Demand) if the relationship between them is established from time to time for each type of water.

BOD is an important parameter for wastewater treatment plants, but since its determination is complex and very long, the COD analysis is preferred for its simplicity and speed.

 

To carry out the COD analysis it is necessary to have:

  • precision micropipette for sample measurement,
  • thermoreactor for heating the sample (150 ° C for 2 hours),
  • test tube holder for cooling hot tubes,
  • photometer or spectrophotometer with cell holder for 16 mm round tubes (eg: UviLine)
  • MONOTEST COD kit of the right concentration.

 

Each MONOTEST COD kit contains 21 round tubes of 16 mm optical glass closed with a screw cap. Twenty test tubes contain the necessary reagent for the analysis, based on potassium dichromate and sulfuric acid, the twenty-first  tube contains the white for the zeroing of the instrument.

To perform the analysis it is necessary to add a precise quantity of sample in a test tube containing the reagents. Then the tube is heated in a thermoreactor and, after cooling to room temperature, the absorbance of the sample is measured with either a photometer or a spectrophotometer, determining the concentration in mg / L of COD.

 

MONOTEST KIT for the analysis of the COD available:

 

The version without Mercury is also available. It is equally precise, but more sensitive to interference from chlorides.