I am trying to find if Inorganic compounds contribute any COD value. If a waste stream contain Na2SO4, it is expcted to have TDS dpending on its % but very little COD.
So no anarobic or aerobic treatment will be useful. Please confirm
The Chemical Oxygen Demand (COD) test uses a strong chemical oxidant in an acid solution and heat to oxidize organic carbon to CO2 and H2O. By definition, chemical oxygen demand is “a measure of the oxygen equivalent of the organic matter content of a sample that is susceptible to oxidation by a strong chemical oxidant. Oxygen demand is determined by measuring the amount of oxidant consumed using titrimetric or photometric methods. The test is not adversely affected by toxic substances, and test data is available in 1-1/2 to 3 hours, providing faster water quality assessment and process control. COD test results can also be used to estimate the BOD results on a given sample. An empirical relationship exists between BOD, COD and TOC. However, the specific relationship must be established for each sample. Once correlation has been established, the test is useful for monitoring and control In the presence of NaCl and NaOH in which the degradation of the COD and T-N occurs through both direct and indirect oxidation. The electro- chemical oxidation of many organic pollutants in aqueous solutions on anode can take place through direct electron or oxygen atom transfer. Measurement of the COD of a spent caustic solution involves firstly digestion of a test sample with dichromate solution and secondly measurement of dichromate remained by titration by ferrous ammonium sulphate to an end point. The potentiometric end point is sharp and easily identified especially for the samples with high turbidity and colour that other methods such as colorimetric in this type of sample do not result in high precision. Because interim of titration responds quickly to potential changes within the [Cr+6/Cr+3& Fe+2/Fe+3] solution producing stable readings that is lead to accurate COD measurement. Finally, results are compared with data determined using colorimetric method for standard samples. It is shown that the potentiometric end point titration with gold rode electrode can be used with equal or better facility
Thank you All. It saved my time. I also found that Inorganic compounds do not yield COD value.
- Badges
- Science topic
- Similar topics
- Geoscience
- Asia
- India