A novel chitosan/diatomite composite was prepared by a simple mixture in the mass ratio to remove methyl orange (MO) from aqueous media in this study. The composite adsorbent was characterized by Fourier transform infrared spectroscopy and scanning electron microscopy analysis. The parameters to influence the adsorption of MO were studied under such conditions as kinetics, adsorption isotherm, pH effect, and thermodynamics. The results revealed that adsorption of MO was initially rapid and the equilibrium time was reached after 40 min. The optimal value of the pH was 5.0 for better adsorption. The equilibrium data were well fitted to the Langmuir isotherm compared to the Freundlich isotherm, and exhibited the highest capacity and a removal rate of 88.37% under an initial dye concentration of 50 mg/L. The kinetic data were well described by the pseudo-second order model. The thermodynamic calculations revealed that the sorption was viable, spontaneous, and exothermic under the conditions studied. In addition, the chitosan/diatomite composite had good adsorption and desorption performance with respect to reusability after six cycles. These results showed that the chitosan/diatomite could be considered as a potential adsorbent for the removal of MO in aqueous solution.

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Abstract:The catalytic decomposition of N 2 O was investigated over Cu-Zn/ZnAl 2 O 4 catalysts in the temperature range of 400-650 • C Catalytic samples have been prepared by wet impregnation method. Prepared catalysts were characterized using several techniques like BET surface area, X-ray diffraction (XRD), and Scanning electron microscopy (SEM). The Cu-Zn/ZnAl 2 O 4 showed higher catalytic performance along with long term stability during N 2 O decomposition. The Cu-Zn/ZnAl 2 O 4 catalysts yielded 100% N 2 O conversion at 650 • C. The Cu-Zn/ZnAl 2 O 4 catalysts are promising for decrease this strong greenhouse gas in the chemical industry.