Study on the Treatment of Dyeing Wastewater by Coagulant Prepared From Red Mud

Making full use of effective elements in the red mud of industrial waste residue to prepare efficient and cheap poly-aluminum-ferric coagulant.And the optimal leaching conditions of Fe、Al in the red mud determined by orthogonal experiments are as following: liquid/solid = 10:1,the concentration of hydrochloric acid is 5mol/L,the temperature is 90℃.The totle leaching rate of Fe、Al reached 93.15% under the best leaching conditions.The effect of coagulant prepared by polymerization of adding sodium hydroxide under that conditions was optimal when the dosing quantity was 10mL/L,pH value of simulated dyeing wastewater was 7.0,and in this case the turbidity removal rate reached 98.5% and the chroma removal rate reached 96.3%.