testingmethodsop

 PURPOSE: To describe the Laboratory standard operating procedure for measurement of Chemical Oxygen Demand of Water and Waste Water samples. SCOPE: Applicable to the Laboratory for analysis of Water and Waste Water samples, where measurement of Chemical Oxygen Demand is required.   RESPONSIBILITY:  Lab chemist: Analysis of sample for measurement of Chemical Oxygen Demand. Technical Manager: Review of activity  Quality Manager: Implementation and compliance of SOP. PROCEDURE:  Principle: A sample is refluxed in strong acidic solution with a known excess of potassium dichromate (K2Cr2O7).After digestion the remaining unreduced K2Cr2O7 is titrated with ferrous ammonium sulphate to determine the amount of potassium dichromate (K2Cr2O7) consumed and the oxidizable matter is calculated in terms of oxygen equivalent.  Instrument and Equipment: Heating Mantle, Burette 50 ml. Round Bottom Flask 500 ml Pipettes 50ml. Measuring Cylinders Reagents:  Preparation o...