The investigation of the treatment of dyeing wastewater by galvanic corrosion-reduction degradation-coagulation absorption

A new method for treating dyeing waste water with iron filings, flue gas or gas ashes as treating agent is introduced. The treatment mechanism is discussed and the proper treating conditions and technological procedures are suggested. The experimental results show that when the ratio of treating agent is 4:6, pH values of iron filings filtering and coagulation absorption are controlled at 4～5 and 8～9 respectively, treating time is 20～30min, the rate of dislodgement and decolouring after treating can reach over 90%; all the values of COD are less than 100mg/L; the waste water becomes clear and transparent; and all the quality indexes of water conform with the national dischange standards.