yes. BOD data will describe the water health and degradation process roles by bacteria activities. While COD is more accurate to describe about water health dealing with organic content

Surely. As the acronyms indicate, the purpose of your research dictates which one or both to be measured.

The quality of water is determined by several factors. Apart from BOD and COD, pH, Ec cations anions etc also play an important part. But it depends what is your objective. Both BOD and COD are important aspects of water quality

Yes, both are important.

BOD is indirect measures of biodegradable organics in water.

COD is indirect measures of total organic pollution in water.

COD - BOD = Total non biodegradable organics.

In this way, by measuring both BOD and COD we will get a clear picture of water pollution. This will help in arranging and design of suitable treatment facility.

Thanks for all the feedback!

I am planning in proposing a new Water Quality Index (WQI) in Malaysia.

In Malaysia, we are currently taking both COD and BOD as parameters to be used in evaluating the water quality status. As COD and BOD are actually having a high co-relationship, that's why I am thinking is it possible to eliminate one parameter to determine the water quality index.

Jacky Wong. i have worked in this field and have few publications . see the link below. hope it will be useful.

Article Comparative evaluation of water quality zonation within Dwar...

Article An evaluation of irrigation water suitability in the Dwarka ...

Article Search for potential iron contamination zones in Burdwan dis...

Article Sensitivity analysis and mapping the potential groundwater v...

Yes, both are important.

Basically COD contains BOD also and the results are available within 3 to 4 hours, whereas BOD results are available only after minimum 3 days, usually 5 days.

To evaluate the quality of sea water espacialy, you need also to measure other parameter as NO3-, NH4+, chlorophyl a, temperature, trace elements, havy metals, etc..

You can find an example of all parametres you should measured in the Dirictive Cadre sur l'Eau (2000).

Dear Researchers.

Both BOD and COD are to be assessed to evaluate bio and non bio matter.

@Nafees Mohd. has indicated well the main difference. COD gives a quick assessmnt in 4hrs whereas BOD takes the usual 4 to 5 days.

When you desire bio or natural type waste water treatment it is best to have COD only 25-30% more than BOD. If the difference is more, 1stly neutralise the non bio matters.

Municipal sewage waste water will have BOD to indicate bio degradables and COD marginally more.

However effluents from Chmcl Indstries would have larger difference between

BOD -COD ..

Well wishes from

Prof Ajit Seshadri. Vels University.

Chennai. INDIA ..

To define BOD, it needs to specify the no. of days of incubation. The most common test is BOD5, i.e. 5-day BOD. There are also some uncommon tests of BOD7 and UBOD (Ultimate BOD which needs 30-60 days) The UBOD measures the total amount of biodegradable oxidizable substances in water. The ratio BOD5 to UBOD depends on the ease of biodegradation.

COD measures the total amount of substances that can be oxidized under the harsh conditions in dichromic acid. It will oxidize all organic compounds, no matter they are biodegradable or not. The ratio of COD to UBOD will depends on the biodegradability of the substances.

Both COD and BOD not only oxidize carbon in organic compounds, inorganic compounds such as ammonia, sulfide, ferrous ions will also contribute BOD or COD. If you want to measure the carbonaceous BOD or COD, you need to eliminate these interferences or subtract their effect. Moreover, you can measure the total organic carbon (TOC) as a reference.

According to me, to determine the quality of water, many physico-chemical parameters including COD and BOD affects. Exceed in any of these parameters individually or multiply indicates the water get polluted. For your purpose, I think all these parameters should be included in the Water Quality Index (WQI), because any of the parameter indicates the water body get polluted.

I think both parameters are important because they measure different type of compounds. And the ratio COD/BOD is an useful indicator about the type of pollution sources.

The handicap of BOD is the long time it takes. You can run some KMnO4-based test as a surrogate.

In my experience, both COD and BOD5 are important parameters to determine water/wastewater quality. COD will give you an idea of the amount of oxygen required to oxidize the organic material present in the sample, while BOD5 will give you an idea about the amount of biodegradable organic matter in water. If you need to know the total organic carbon present, though, I recommend to quantify the total organic carbon (TOC) in your sample. Other parameters relevant to the characterization of water and wastewater are also: Color (Hazen), Turbidity (NTU), pH, discharge temperature (for effluents), Oils and Greases content, Total Solids, Suspended Solids, Dissolved and Settleable solids , metals, chlorides, etc ... I suggest you to check the Standard Methods for the Examination of Water and Wastewater. Best luck with the project!