Fascination About chemical oxygen demand

Wipe the vials that has a moist towel to remove smudges and fingerprints through the vial and spot them while in the preheated digestor block.

The “cod” image will flash for 3 seconds, then the sample test end result will show up while in the Display screen as section for each million COD. Record the test result.

The COD test should be considered an unbiased evaluate from the natural matter in a wastewater sample instead of a substitute for that BOD test.

Sure. Even though COD needs to be viewed as an impartial test from BOD, and will create a higher concentration examining than BOD for a particular wastewater sample, it is normally approved that COD and BOD share an empirical relationship.

Regulatory Compliance: Lots of nations around the world and regulatory bodies have established COD boundaries and recommendations for discharges into h2o bodies. Monitoring COD aids make sure compliance with these restrictions, which are intended to secure water high-quality and forestall extreme pollution.

Every time a h2o sample is very polluted with natural and organic waste, the oxygen demand will exceed the most equilibrium solubility of O2 in drinking water. This kind of drinking water sample may not comprise any dissolved O2.

If BOD was often employed, a problem Along with the remedy system wouldn’t be detected till five days later on. This may necessarily mean that wastewater would wish to be held for times until finally success could possibly be confirmed.

The dichromate COD reagent is often offered in the sealed vial. Sample is here added into the vial, as well as reaction occurs during a digestion where the sample is heated for two hours at 150oC.

The drinking water sample is boiled with potassium dichromate in a very strongly acidic medium below reflux. The organic compounds current during the sample are oxidized with the dichromate.

The ultimate DO looking at is then subtracted with the Preliminary DO reading through and The end result is the BOD focus (mg/L). Should the wastewater sample expected dilution, the BOD focus reading through is multiplied from the dilution variable.

Chemical Oxygen Demand (COD) more info is a vital parameter in wastewater procedure and drinking water high-quality Assessment. It is just a evaluate of the potential of h2o to consume oxygen over the decomposition of natural and organic issue and also the oxidation of inorganic chemicals including Ammonia and Nitrite.

Chloride is the primary interference when testing for COD. Just about every COD vial utilised Together with the dichromate technique incorporates mercuric sulfate which will get rid of chloride interference approximately the extent specified in the technique.

Monitoring COD aids in optimizing remedy functions and guaranteeing compliance with regulatory benchmarks.

This method continues to be found profitable when the proportions and kinds of materials in a wastewater stay fairly constant.