Industrial scale application of the plunger flow electro oxidation reactor in wastewater depth treatment
Effluents after biochemical treatment contain pollutants that are mostly non degradable. Based upon previous pilot scale test results, an industrial scale electro oxidation device was built to decompose these refractory materials in the effluent from a park wastewater treatment plant. The electro oxidation device comprised a ditch shaped plunger flow electrolysis cell, with mesh plate Ti/PbO2 electrodes as the anode and the same size mesh plate Ti as the cathode. Wastewater flowed vertically through electrodes; the effective volume of the cell was 2.8 m3, and the surface to volume ratio was 17.14 m2 m 3. The optimal current density was 100 A m 2, and a suitable flow velocity was 14.0 m h 1. The removal efficiencies for chemical oxygen demand and color in the effluent were over 60.0 and 84.0 respectively. In addition, the electro oxidation system offered a good disinfection capability. The specific energy consumption for this industrial scale device was 43.5 kWh kg COD 1, with a current efficiency of 32.8 which was superior to the pilot scale one. To meet the requirements for emission or reuse, the operation cost was $0.44 per ton of effluent at an average price for electricity of $0.11 kWh 1.
Environmental Science and Pollution Research