Preparation and characterization of MnO2-impregnated granular activated carbon for Reactive Black 5 removal

Granular activated carbon (GAC) was impregnated with manganese dioxide through an impregnation-precipitation-calcination procedure for removing Reactive Black 5 (RB5) from aqueous solution. The higher Brunauer-Emmett-Teller surface areas (820.25 m(2) g(-1)) and porous structure were obtained for manganese dioxide-GAC. The X-ray diffractometer and scanning electron microscopy analysis revealed that a large amount of manganese dioxide coating on the GAC surface. The optimized manganese dioxide-GAC preparation conditions were Mn(NO3)(2) and Na2CO3 solutions of 0.5 mol L-1, impregnating time of 5 h, calcining time of 3 h and calcining temperature of 360 degrees C. The experimental results indicated that the pseudo-second-order kinetic equation can be used to describe the adsorption of RB5 on manganese dioxide-GAC. The highest removal capacity of RB5 from solution for manganese dioxide-GAC was 4.468 mg g(-1).