COD Removal method of color and COD on dyeing wastewater

摘要

PURPOSE: Provided is a method for eliminating colors and COD from dyeing wastewater by decolorization and coagulation using the complex of magnesium salts and iron salts. Also polymer is used as coagulant aids for solid-liquid separation. The method can decolorize efficiently without a decolorant and save initial costs for equipment. CONSTITUTION: The method to remove colors and COD proceeds to injecting dyeing wastewater with coagulants composed of magnesium salts and iron salts with the weight ratio of 1:1 and reacting the complex at pH 10-11 and settling solids. Magnesium salts and iron salts are used individually of magnesium chloride and iron chloride(II). The method can reduce from 2500 to 100 of color(96% of removal rate) and from 540 ppm to 250 ppm of COD(54% of removal rate).