Kinetic models for the oxidation of organic substrates at boron-doped diamond anodes

• Three kinetic models for the mineralization of organic substrates are presented.
• Models are fitted to the electrochemical oxidation of model substrates and authentic waste materials.
• Proposals are made for the application of these laboratory results to field conditions.

We have studied electrochemical advanced oxidation of three single substrates (oxalic acid, maleic acid, and 2-naphthol) and real wastes (primary sewage, automotive wastewater, and composting leachate), at boron doped diamond, at which anode organic substrates undergo electrochemical mineralization by reactive hydroxyl species. Experimental data obtained under batch conditions at laboratory scale were fitted to three kinetic models under various conditions of current density and substrate concentration. The optimum kinetic regime of linear loss of substrate with time at constant current density can be achieved for almost all substrates to high conversion, except under extreme conditions of low substrate concentration and high current density. Proposals are made for optimizing this kinetic regime to the treatment of real wastes under flow conditions.