Cyanide oxidation from wastewater in a flow electrochemical reactor

In this paper, a flow reactor using the Ti/70TiO(2)/30RuO(2) (w/w) DSA-type electrode was designed for the electrooxidation of cyanide in batch recirculating mode. The device performance was evaluated in terms of the decay of the cyanide concentration as a function of the current density, flow rate, and initial pollutant concentration. The experiments show that cyanide electrooxidation presents pseudo-first-order kinetics with respect to CN- ions. For the operational conditions used in the experiments, the rate constant for cyanide oxidation was in the range from 3 x 10(-5) to 2 x 10(-4) m s(-1), with an optimum value of 1.5 x 10(-4) m s(-1) for a current density of 10 mA cm(-2) and a linear speed of 0.22 m s(-1). Using these parameters, 12 kWh is consumed for the oxidation of 1 kg of cyanide.