The principle of the novel treatment technology of liquid waste treatment is based on free radicals from natural gas flame to destroy organic pollutants through a chemical oxidation process and oxidizes the organic substance in aqueous phase. Its original concept is based on a direct contact between a contaminated liquid stream and the flame of a gas-fired burner containing free radicals such as OH*, H*, CH?3* and CHO*. The high temperature of the flame enables completion of the oxidation of the organic substance, in aqueous phase, by means of the oxygen excess present in flame. Experimental results obtained on a 50kW-test bench shows a pollutant destruction efficiency of 75 to 99% for wastewater contaminated by phenol, toluene, xylenes (ortho, meta and para), or acetone having a concentration varying between 180 and 82,000 ppm. The cumulative specific energy consumption varies from 0.4 to 0.5 kWh/L of treated liquid waste stream.