Dear Saba,

You can use APHA methods to determine the COD and BOD in your samples. For the BOD you can use winkler method and COD - closed reflux method/Open reflux method.

Following links help to find protocols for BOD & COD tests....

https://beta-static.fishersci.com/content/dam/fishersci/en_US/documents/programs/scientific/technical-documents/white-papers/apha-biochemical-oxygen-demand-white-paper.pdf

http://edgeanalytical.com/wp-content/uploads/Inorganic_SM5220.pdf

Yohan Mahagamage

As Yohan Mahagamage explained there are several standard methods available. Basically your can perform those in laboratory (with minimum cost).

Abdulwakil Olawale Saba, based on the standard methods (above mentioned), analytical equipment and methods developed by some companies. Those methods are fairly easy to perform (in case you are looking for an easy method with less labour work (to perform by person with less analytical skills).

For example,

Colorimetry method is easy since all the analyst needs to do is digest the samples and let the instrument do the work. For these reasons, colorimetry is the most common method to measure COD. See the following link for more information. (there are other manufactures than this).

http://blog.hannainst.com/cod-testing

https://www.hach.com/codguide

for BOD also, some manufacturers have developed equipment to assist the researcher. (there are some options you can get values (based on the accuracy you nee) within shorter periods than 5 day (as in normal test).

https://www.hach.com/bodguide

Amila

this paper would be useful.

Article Methods for assessing biochemical oxygen demand (BOD): A review

Check APHA(2005), Tepe and Boyd(2002) or Boyd(1981).

use the APHA method for the analyses of BOD and COD

Follow the protocol mentioned by APHA. BOD can be done by winklers method. You need to have a BOD incubator. COD can be done by reflux method using 0.1N ferrous ammonium sulphate as tritrant and 2-3 dropsferroin as indicator. U need to add 10ml of 0.25N potassium dichromate, 30ml ofsulphuric acid, pinch of mercuric sulphate and silver sulphate to 20 my water sample. Reflux it 2 hours. Cool the sample and make the volume to 140ml. Then titrate it as I have mentioned it above

Thank you all for the insights.

There are no easiest only accurate method should be followed. Consider APHA

This realtime BOD estimation method could be interesting.

Preprint A Real-Time BOD Estimation Method in Wastewater Treatment Pr...