Activation and characterization of environmental catalysts in plasma-catalysis: Status and challenges

Plasma-catalysis has attracted great attentions in environmental/energy-related fields, but the synergetic mechanism still suffers intractable defects. Key issues are that what kind of catalysts are applicable for plasma system, how are they activated in plasma, and how to characterize them in plasma. This review systematically gives a comprehensive summarization of the selection of catalysts and its activation mechanism in plasma, based on the character of plasma, including physical effects containing the enhancement of discharge intensity and adsorption of reactants, and the utilization of plasma-generated active species such as·O, heat, O₃, ultraviolet light and e* . Focus is given to the illumination of the activation mechanisms of catalysts when placed in plasma zone. Subsequently, the novel characterization techniques for catalysts, which may associate properties to performance, are critically overviewed. The challenges and opportunities for the activation and characterizations of catalysts are proposed, and future perspectives are suggested about where the efforts should be made. It is expected that a bridge between catalysts design and character of plasma can be built to shed light on the synergetic mechanism for plasma-catalysis and design of new plasma-catalysis systems.

Coupling cold plasma and membrane photobioreactor for enhanced fouling control during livestock excreta treatment

To treat high-turbidity livestock excrements (LE), this study suggests a synergistic system coupling cold plasma (CP) and membrane photobioreactor (MPBR). During the continuous operation of the integrated system, physico-chemical oxidation of CP decompose turbidity and total suspended solids (TSS) up to 99.9%. The microalgal concentration of Scenedesmus obliquus in the following MPBR reach as high as 1,944 mg D.W./L, which indicates the residual organic and inorganic substances were actively consumed by phototrophic metabolism. Pearson correlation analysis confirms this synergistic relationship of turbidity and TSS with biological growth parameters such as biomass growth, soluble microbial products, and extracellular polymeric substances. Results evidence that the turbidity and TSS are directly connected to the microalgal growth in this integrated system thus the role of CP is crucial to achieving the LE treatment goal. Overall, this study provides a guideline to support the enhanced treatment strategy to control LE with the production of bioresources for sustainable carbon and nutrient cycles.

In situ and ex situ NO oxidation assisted by sub-microsecond pulsed multi-pin-to-plane corona discharge: the effect of pin density

Pin-to-plane corona reactor for NO to NO₂ conversion at ambient conditions.

Nitric oxide decomposition using atmospheric pressure dielectric barrier discharge reactor with different adsorbents

An NO removal rate of 99% and energy efficiency of 99.4 g NO per kW h were obtained on NaY zeolite using the adsorption–desorption and decomposition process in a self-made coaxial cylinder-type dielectric barrier discharge reactor.