In this paper, the feasibility of waste water oxidation treatment in superheated near-critical region of water is studied through experiments. Five kinds of typical industrial organic wastewater which are difficult to biodegrade are chosen for purification experiments. They are coking wastewater, penicillin wastewater, papermaking wastewater, acrylonitrile wastewater and TNT wastewater, respectively. The temperature of the experiment is 420-530℃ and the pressure 21-26 MPa. The results show that at a constant pressure the CODcr removal ratios of the five kinds of wastewater are increasing rapidly with temperature increase,whereas at a constant temperature the CODcr removal ratios are only slightly increased as the pressure increases. Additionally, the differences of CODcr removal rates and purification rate of water in the outlet of the system at different pressures are gradually reduced as the temperature increases. Under conditions of temperature at 520-530℃ and pressure at 21 MPa, the purified CODcr values of the five typical kinds of wastewater are less than 200 mg/L, even less than 100 mg/L. Through a technological and economic analysis, it is pointed out that considering the engineering practice, the superheated and near-critical water oxidation is more suitable for industrial organic wastewater treatment, instead of the supercritical water oxidation technology.

treatment of organic wastewater  /  superheated and near-critical water oxidation  /  supercritical water oxidation