Catalytic wet air oxidation of a non-azo dye with Ni/MgAlO catalyst

The catalytic activity of Ni supported over hydrotalcite by impregnation (Ni/MgAlO) as catalyst for Basic Yellow 11 (BY11) degradation under moderate conditions was investigated. BET, XRD and XRF were employed to characterize the catalyst. To evaluate the catalytic system, wet air oxidation of dye was carried out at temperatures between 100 and 200 °C, and oxygen pressures ranging from 30 to 60 bar. The effect of initial concentration from 100 to 400 ppm on the degradation of Basic Yellow 11 was also investigated. The degradation process was monitored by UV–VIS spectroscopy, TOC and toxicity analyses. At 150 °C, 50 bar oxygen pressure and 200 ppm initial concentration, 64.5% selectivity towards CO2 was obtained after 3 h of treatment, while only 20.2% selectivity was achieved without catalyst at the same experimental conditions. The structure and morphology of the catalyst under different cycling runs show that the catalyst is stable under such operating conditions and the leaching tests show low leaching effect.

• Ni supported over hydrotalcite calcined precursors as catalyst.
• Catalytic wet air oxidation in batch reactor for Basic Yellow 11 removal.
• Effects of reaction conditions and catalyst stability were tested.
• The catalyst proved to be stable and efficient for the dye degradation.