p-Nitrophenol contaminated soil remediation in a spray-type coaxial cylindrical dielectric barrier discharge plasma system.

In the present work, plasma remediation of p-nitrophenol (PNP) contaminated soil was performed in a novel spray-type coaxial cylindrical dielectric barrier discharge (DBD) system at ambient temperature. This system is capable of generating large-size nonthermal plasma (NTP) and improving the diffusion and transfer of chemical active species around the dispersed soil particles. Several key parameters including plasma treatment time, discharge voltage, soil granular size, the entry speed of soil, PNP initial concentration, gas variety, and gas flow rate were investigated in terms of PNP degradation and energy efficiencies.

Degradation of toluene by tube-tube coaxial dielectric barrier discharge: power characteristics and power factor optimization.

In this paper, the power characteristics and power factor optimization were investigated in a coaxial tube-tube dielectric barrier discharge (DBD) reactor. The effects of several parameters, including discharge voltage, discharge length, discharge frequency and gas flow rate on discharge power and power factor have been evaluated. The experiment results showed that higher discharge power can be obtained by increasing the discharge voltage, discharge frequency and electrode length.

The post plasma-catalytic decomposition of toluene over K-modified OMS-2 catalysts at ambient temperature: Effect of K loading amount and reaction mechanism.

The present work is devoted to study the post plasma-catalytic (PPC) degradation of toluene using packed-bed discharge (PBD) plasma over K-modified manganese oxide octahedral molecular sieve (OMS-2) catalysts at ambient temperature. Compared to plasma alone, PPC can significantly improve the toluene degradation and mineralization performance simultaneously, and the generation of discharge byproducts and organic intermediates is suppressed. The catalytic capacity of OMS-2 for toluene degradation is greatly promoted by tuning potassium ions (K) content in OMS-2 tunnel, which might be owing to the formation of more surface active oxygen species derived from weak Mn-O bonds, plenty of oxygen vacancies, as well as more superior low-temperature reducibility.

Degradation of toluene by pulse-modulated multistage DBD plasma: Key parameters optimization through response surface methodology (RSM) and degradation pathway analysis.

In the present work, a pulse-modulated high-frequency (HF) dielectric barrier discharge (DBD) plasma has been employed and utilized to evaluate the feasibility of toluene degradation in a multistage rod-type reactor at room temperature. Experimental result indicates that the energy consumption is significantly reduced and heating effect can be effectively suppressed when the DBD plasma is ignited in pulse-modulated mode instead of continuous mode. The response surface methodology (RSM) based on central composite design (CCD) model has been proposed to evaluate the contribution of key operating parameters including duty cycle and modulation frequency.

Characterization of highly effective plasma-treated g-CN and application to the photocatalytic HO production.

Plasma treated g-CN (PT-g-CN) was obtained by a simple and rapid DBD plasma modification process on the pristine g-CN. Compared with the pristine g-CN, the grain size of the PT-g-CN decreased from 99.2 nm to 57.

Pulsed discharge plasma induced WO catalysis for synergetic degradation of ciprofloxacin in water: Synergetic mechanism and degradation pathway.

Pulsed discharge plasma (PDP) was adopted to induce WO for synergetic degradation of ciprofloxacin (CIP) in water. WO was firstly characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET), X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction (XRD), UV-Vis diffuse reflectance spectroscopy (DRS), Photocurrents and Photoluminescence. The degradation results showed that PDP could induce WO photocatalysis successfully, and a synergetic effect was established in PDP/WO system.

Degradation of antibiotic chloramphenicol in water by pulsed discharge plasma combined with TiO/WO composites: mechanism and degradation pathway.

Pulsed discharge plasma (PDP) combined with TiO/WO composites for chloramphenicol (CAP) degradation was investigated. The prepared TiO/WO composites were characterized by scanning electron microscope, transmission electron microscope, nitrogen adsorption apparatus, zeta sizer, X-ray diffraction, Raman spectra, UV-Vis absorption spectroscopy, X-ray photoelectron spectroscopy, photocurrent and electrochemical impedance spectroscopy. The degradation performance showed that the addition of TiO/WO composites significantly enhanced the removal efficiency of CAP in PDP system.

Plasma-catalytic destruction of xylene over Ag-Mn mixed oxides in a pulsed sliding discharge reactor.

Plasma-assisted catalytic degradation of xylene was performed in a pulsed sliding dielectric barrier discharge (SLDBD) reactor based on three-electrode geometry over Ag-Mn bimetallic oxides catalysts at room temperature. Experimental results showed that more active species were distributed uniformly in the SLDBD plasma than traditional surface dielectric barrier discharge (SDBD), contributing to higher degradation and energy performance. The xylene degradation efficiency and energy yield in the SLDBD reactor driven by both +pulse (+18 kV) and -DC (-10 kV) were 40% and 2.

Synergistic degradation of trans-ferulic acid in aqueous solution by dielectric barrier discharge plasma combined with ozone.

Trans-ferulic acid (FA), extensively used in pharmaceutical and olive oil industries, causes huge risks to ecological environment due to its biotoxicity and phytotoxicity, leading to the difficulty of biochemical processes in treating FA wastewater. In this study, synergistic degradation of FA via dielectric barrier discharge (DBD) plasma and O (plasma-ozone) was studied. The results showed that FA degradation efficiency reached 96.

Optical characteristics of the filamentary and diffuse modes in surface dielectric barrier discharge.

Surface dielectric barrier discharge (DBD) plasmas generally exhibits filamentary and diffuse discharges at atmospheric air. The focus of this investigation is on the different optical characteristics and quantitative research about morphological features of two discharge modes. The temporally and spatially resolved characteristics of discharge phenomenon together with the gas temperature are presented with microsecond time scale.

Performance evaluation of non-thermal plasma injection for elemental mercury oxidation in a simulated flue gas.

The use of non-thermal plasma (NTP) injection approach to oxidize elemental mercury (Hg(0)) in simulated flue gas at 110°C was studied, where a surface discharge plasma reactor (SDPR) inserted in the simulated flue duct was used to generate and inject active species into the flue gas. Approximately 81% of the Hg(0) was oxidized and 20.5μgkJ(-1) of energy yield was obtained at a rate of 3.

Effects of electrode geometry on the performance of dielectric barrier/packed-bed discharge plasmas in benzene degradation.

In this study, the effects of electrode geometry on benzene degradation in a dielectric barrier/packed-bed discharge plasma reactor with different electrodes were systematically investigated. Three electrodes were employed in the experiments, these were coil, bolt, and rod geometries. The reactor using the coil electrode showed better performance in reducing the dielectric loss in the barrier compared to that using the bolt or rod electrodes.

Innovative approach for benzene degradation using hybrid surface/packed-bed discharge plasmas.

An innovative plasma reactor, which generates hybrid surface/packed-bed discharge (HSPBD) plasmas, was employed for the degradation of benzene. The HSPBD reactor was found to display remarkably better benzene degradation, mineralization, and energy performance than surface or packed-bed discharge reactors alone. The degradation efficiency, CO2 selectivity, and energy yield in the HSPBD reactor were 21%, 11%, and 3.

[Emission spectra of hydroxyl radical generated in air corona discharge].

In this paper, the relative emission intensity of the 309 nm transition band of hydroxyl radical (OH) was measured by a CCD imaging spectrometer in a pin-plane corona discharge scheme of one atmosphere pressure air injected with unsaturated water vapor from the central hole of the used pins. The influences of several factors on the OH radical production were investigated by relative emission intensity measurement. The production of OH radical increased with a limited increment of water vapor concentration in the mixed gas.