摘要
The electrochemical oxidation of stabilized landfill leachate with 2960 mg L鈭? chemical oxygen demand (COD) over a Ti/IrO2-RuO2 anode was investigated in the presence of HClO4 as the supporting electrolyte. Emphasis was given on the effect of electrolysis time (up to 240 min) and temperature (30, 60 and 80 掳C), current density (8, 16 and 32 mA cm鈭?), initial effluent's pH (0.25, 3, 5 and 6), HClO4 concentration (0.25 and 1 M) and the addition of NaCl (20 and 100 mM) or Na2SO4 (20 mM) as source of extra electrogenerated oxidants on performance; the latter was evaluated regarding COD, total carbon (TC), total phenols (TPh) and color removal. Moreover, the anode was studied by scanning electron microscopy and cyclic voltammetry. The main parameters affecting the process were the effluent's pH and the addition of salts. Treatment for 240 min at 32 mA cm鈭? current density, 80 掳C and the pH adjusted from its inherent value of 0.25 (i.e. after the addition of HClO4) to 3 yielded 90%COD, 65%TC and complete color and TPh removal at an electricity consumption of 35 kWh kg鈭? COD removed. Comparable performance (i.e. 75%COD reduction) could be achieved without pH adjustment but with the addition of 100 mM NaCl consuming 20 kWh kg鈭? COD removed.