Wet electrolytic oxidation of organics in the presence of electrolytes and externally added oxygen gas was investigated for wastewater treatment. The experimental apparatus was a 300 ml electrolytic batch autoclave operated mainly at 250 degrees C and 7 MPa. The results showed that the presence of halide ions such as chlorides and bromides strongly catalyses the conversion of pollutant organic compounds to innocuous compounds such as CO2 and water. The addition of external oxygen gas in wet electrolytic oxidation of acetic acid strongly suppressed the cathodic evolution of hydrogen gas and demonstrated a TOC removal profile with an apparent current efficiency higher than 100% for high concentration acetic acid solutions.