Wastewater of the dyeing unit of the Hanoi textile-dyeing Company (Hanosimex) was treated by coagulation method with the HBM/KT powder and by catalytic oxidation with the hydrogen peroxide (H2O2) over HBM/TB catalyst. HBM/KT coagulator and HBM/TB catalyst were prepared at the Laboratory of Surface Sciences and Catalysis, Institute of Chemistry, Vietnamese Academy of Science and Technology. The obtained results demonstrated that the combination of the coagulation method with the catalytic heterogeneous oxidation would be an appropriate technique for effectively treating reactive dyeing effluent.