Preparation of Manganese Blending-Modified Activated Coke for Flue Gas Desulfurization.

In this study, the preparation and desulfurization application of MnO2 and pyrolusite blending-modified activated cokes (ACM and ACP) were studied. Thermodynamic calculation shows that the blended metal oxides could be reacted with the solid carbon and gaseous products H2, CO, and CO2 for activation. The physicochemical properties of the blending-modified ACP and ACM responded considerably differently to preparation conditions. The blended metal oxide significantly improved the mesoporous structure of the modified activated cokes, as well as the surface acidic and basic functional groups. Different metal oxides played different roles in the pore structure and surface functional group evolution, and the current investigation indicates that MnO2 is more favorable than pyrolusite. The enhanced acidic and basic functional groups, coupled with the catalysis of metal oxides, improved the desulfurization performance of the modified activated cokes. The sulfur capacities of the prepared ACP and ACM were 47.9-208.9 and 119.4-205.9 mg/g, respectively, which were much greater than the sulfur capacity of the fresh activated coke.

In Situ Growth Synthesis of the CNTs@AC Hybrid Material for Efficient Nitrate-Nitrogen Adsorption.

Nitrate-nitrogen (NO3-N) is a common pollutant in aquatic environments and causes many environmental issues and health problems. This study successfully applied the activated AC@CNT composite synthesized by CNTs in-situ growth and post-treated by myristyltrimethylammonium bromide (MTAB) for NO3-N adsorption from wastewater. The results show that the highest NO3-N adsorption capacity of AC@CNTs-M was 14.59 mg·g-1. The in-situ growth of CNTs gave a higher specific surface area and more mesoporous volume, while MTAB uniformly occupied part of the pore structure after the modification process. The AC@CNTs-M had more surface functional groups of hydroxyl and carboxyl, which are favorable for the adsorption of NO3-N. The NO3-N adsorption on AC@CNTs-M was best defined by the pseudo-second-order model, and the isothermal analysis shows that NO3-N adsorption is a multiple process with a maximum adsorption capacity of 27.07 mg·g-1. All the results demonstrate the great potential of AC@CNTs-M for NO3-N adsorption from water, especially in acidic wastewater.

Novel synthesis of Pd-CeMnO3 perovskite based on unique ultrasonic intervention from combination of Sol-Gel and impregnation method for low temperature efficient oxidation of benzene vapour.

The 0.5 wt% Pd-CeMnO3 was prepared by ultrasonic intervention combination of Sol-Gel and PVA-protected N2 bubbling NaBH4 reduction impregnation method, then it was used for the catalytic oxidation of benzene vapour at low temperatures. By analyzing the removal and mineralization rate at different temperatures, it was found that 50% of benzene was degraded in 145 °C, then 90% of benzene was degraded in 186 °C, 100% of mineralization rate was 220 °C. After ultrasonic treatment, 64% removal rate and 46% mineralization rate could be increased, it proved that ultrasonic treatment can improve the performance of catalyst significantly. According to XRD spectrum, ultrasonic intervention helped to stabilize the crystalline structure of perovskite. Further, SEM pictures intuitively proved that ultrasonic treatment contributes to the formation of surface pore structure of catalyst. Moreover, diagram of H2-TPR indicates that ultrasonic intervention makes the catalyst have more cryogenic activity sites for strong low temperature catalytic activities. All these reasons are assumed to be the factors that lead to superior performance of the catalyst.