Oxidative degradation of Congo red using zeolite Y as a support for Co(II), Ni(II) and Cu(II) ions

Abstract

In this paper, the potential of Co(II), Ni(II) and Cu(II) incorporated zeolite Y prepared via wet impregnation process, was studied in Catalytic wet air oxidation of Congo red. The catalysts were characterized with AAS, FTIR, XRD, SEM, BET Surface area and cation exchange capacity measurement. The results revealed that all the three incorporated zeolite Y catalysts showed significant loss of crystallinity due to the heavy loading of respective metal ions. The dye was decolourised to the extent of 95.90, 97.54 and 87.79% by Co(II)–zeolite Y, Ni(II)–zeolite Y and Cu(II)–zeolite Y respectively in 4 h at a solution pH of 6.4, catalyst load of 1.5 g L−1, initial dye concentration of 10.0 mg L−1 and temperature 303 K. All the reactions followed second order kinetics with good linearity (Regression coefficient R = 0.95–0.97). The overall chemical oxygen demand reduction of the dye with Co(II)–zeolite Y, Ni(II)–zeolite Y and Cu(II)–zeolite Y were 95.51, 98.62 and 90.70% respectively, confirmed the mineralization of the dye. Thus these incorporated catalysts could be considered as promising catalysts for the degradation of Congo red and they can be recovered and reused up to three consecutive runs effectively.