Condition optimization of amperometric determination of chemical oxygen demand using boron-doped diamond sensor

The amperometric determination of chemical oxygen demand (COD) reported by Quan Xie's group (Electrochem Commun 9:2281, 14), was a rapid, green and simple COD evaluation method. This work focused on testing and verifying this method by using a home-made boron-doped diamond (BDD) film as anode and optimizing the experiment conditions. The BDD thin film electrode was employed as anode and the electrochemical process was run with different experimental parameters including counter electrode, electrode gap, applied potential, electrolyte pH, and temperature. Standard samples were determined in the optimum conditions, a linear range of 19.2-11,600 mg l(-1) COD and a low detection limit of 0.192 mg l(-1) COD were well established with the present approach. The COD value of the simulated organic wastewater determined by this method agreed well with the standard dichromate method, and it showed good accuracy, stability, and reproducibility.