Effect of Cu（Ⅱ） on Degradation and Decolorization of Rhodamine B in Subcritical Water

In this paper, subcritical water, an environmentally friendly solvent, was employed to degrade rhodamine B, which served as a model dye in textile industrial effluents. The effect of Cu（Ⅱ） on the degradation of rhodamine B was evaluated. Further, the degradation kinetics of rhodamine B in subcritical water was evaluated via a Weibull model. The results show that subcritical water could efficiently degrade and decolorize rhodamine B. The addition of Cu（Ⅱ） into subcritical water could accelerate the degradation of rhodamine B and lower the temperature for its com- plete degradation. The Weibull equation could well express the degradation kinetics of rhodamine B. The calculated rate constants showed Arrhenius behavior and presented high correlation coefficients. The activation energy was 109.4 kJ/mol for subcritical water degradation of rhodamine B, whereas it became lower（93.4 kJ/mol） when Cu（Ⅱ） was added to the subcritical water. The frequency factors for the degradation of rhodamine B by subcritical water without and with Cu（Ⅱ） were calculated to be 1.0×10n and 3.2×109 min-1, respectively. The above results indicate that subcritical water treatment is a promising process for degrading and decolorizing textile dyes. The results will provide a theoretic support for the industrial application of subcritical water treatment.

A New Strategy for Improving the Efficiency of Low-temperature Selective Catalytic Reduction of NOx with CH4via the Combination of Non-thermal Plasma and Ag2O/TiO2 Photocatalyst

In the present work,a remarkable combination of non-thermal plasma and photocatalyst was developed to widen the operating temperature window of selective catalytic reduction(SCR)of NOx with CH4,especially to improve the low-temperature removal efficiency of NOx.It was shown that the operating temperature window was significantly widened.Among all the catalysts prepared,1%Ag2O/TiO2 showed the highest catalytic activity for NOx removal due to the utilization of near ultraviolet light.The conversion of NOx to N2 over the in-plasma 1%Ag2O/TiO2 photocatalyst at 60 and 300℃ could achieve 31.8%and 53.0%,respectively.The combination mode of plasma and catalyst affected NOx removal efficiency greatly,the in-plasma catalysis outperformed the post-plasma catalytic mode remarkably,signifying the contribution of photocatalytic processes on the catalysts.Meanwhile,the characterizations of the catalyst demonstrated that the morphology and structure of the Ag2O/TiO2 catalyst were unchanged throughout the non-thermal plasma and photocatalytic processes,implying the superior stability of the catalyst.