METHOD FOR TREATING HARMFUL WASTEWATER USING FREEZING THICKENING AND APPARATUS THEROF

摘要

PURPOSE: Provided are a method for treating harmful wastewater using freezing thickening and an apparatus thereof. The method uses the natural phenomena of the generation of ice crystals from pure water particles and the separation and thickening of pollutants in wastewater around the ice crystals according to the fall of temperature below the freezing point. The method is efficient for industrial wastewater, landfill leachate and livestock wastewater containing nondegradable materials and poisonous not to be treated by conventional biological processes or physical and chemical processes. CONSTITUTION: The apparatus consists of the following parts: a crystallizing tank installed with freezing partitions with the interval of 6-10 cm and located in the bottom of the apparatus; a crystal growth tank (2) at the upper the former tank; a separating tank (3) at the upper to separate the ice crystals from thickened liquid; a melting tank (4) at the outer separation tank (3) and the inner heat exchange to melt the separated ice crystals and to cool influent wastewater; a cover (6); a power source (7) to rotate the central axis installed impellers with the slope of 15-30 degrees; a pump (8) for the inflow of wastewater and the withdrawal of thickened liquid; a refrigerant compressor (9); an auxiliary fan (10) for condensing; and a copper pipe (11). Wastewater with 500-1000ppm of the concentration of suspended solids needs for filtration or centrifuge and wastewater with 1000ppm of that needs for a centrifugal process as a previous treatment.