Will the presence of Hydrogen Peroxide interfere with COD methods?
Hydrogen Peroxide (H2O2) interference on COD method
Hydrogen Peroxide (H2O2) will give a positive error if present. If the concentration of hydrogen peroxide is known in the sample, a blank can be made up containing the same concentration of hydrogen peroxide in distilled water. Add 2 mL of this to a COD vial and test according to the test procedure. The COD value due to hydrogen peroxide can be subtracted from the sample COD value. The Hydrogen Peroxide can also be removed by making the sample (100 mL) alkaline, bring to a boil, and add 0.05 grams of Nickel sulfate. Boil this for one minute. Volatile organics will be boiled off and will not give a COD value.