Determination of chemical oxygen demand in high-salinity produced water

The chloride found at water and wasters causes substantial erroneous results when determining chemical oxygen demand (COD) by methods based on oxidant consumption. Chloride and other halogen ions consume the oxidant and causes positive error on the results. The degree of the error depends on the amount of organic matter and chloride present at the sample. Since mercury ions form complexes with chloride ions the effect of chloride is masked at the oxidation reaction of the organic matter. In this study it is shown that only mercury sulphate use can not prevent the erroneuos results due to oxidation of chloride ions. In addition to mercury sulphate it is necessary to use more weak digestion solution to be able to obtain correct COD values in water/wastewater samples containing high salinity and low organic matter.

کلیدواژه ها:

Chemical Oxygen Demand ، Produced Water