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The effect of a novel hollow annular micro-hole electrode on the DBD de-NO x performance was investigated. The experimental results show that the hollow electrode allows the feed gas to take full advantage of the redundant heat of the electrode, thus reducing the energy consumption of the system. Subsequently, the micro-hole structure can improve the uniformity of feed gas in the plasma channel and prolong the residence time of the feed gas in the plasma channel. The reactor can also raise the temperature of the feed gas and enhance the plasma electric field. The optimum NO x removal efficiency of about 82.6% is achieved at 16 annular micro-holes. Compared to the rod electrode reactor, the novel electrode reactor shows 19.7% reduction in energy consumption and 13.2% enhancement in de-NO x efficiency. The calculations of de-NO x mechanism show that the NO 2 concentration decays significantly as the feed gas residence time increases, accompanied by a slight increase in N 2 O concentration. The NO 2 concentration marginally increases while N 2 O concentration slightly decreases as the increase of feed gas temperature. DBD de-NO x presents the mode of accelerated reduction of NO, essential removal of NO 2 , and gradual consumption of N 2 O with the reduced electric field increases. [Display omitted] • A novel DBD reactor with hollow annular micro-holes electrode was proposed. • The reactor prolongs hazardous gas residence time and reduces heat loss. • The reactor showed 13.2% rise in de-NO x efficiency, 19.7% reduction in energy. • The kinetics mechanisms of hollow micro-holes electrode on plasma de-NO x were study. [ABSTRACT FROM AUTHOR]

In this study, the atmospheric dielectric barrier discharge (DBD) plasma was proposed for the degradation of polystyrene microplastics (PS-MPs) for the first time, due to its ability to generate reactive oxygen species (ROS). The local temperature in plasma was found to play a crucial role, as it enhanced the degradation reaction induced by ROS when it exceeded the melting temperature of PS-MPs. Factors including applied voltage, air flow rate, and PS-MPs concentration were investigated, and the degradation products were analyzed. High plasma energy and adequate supply of ROS were pivotal in promoting degradation. At 20.1 kV, the degradation efficiency of PS-MPs reached 98.7% after 60 min treatment, with gases (mainly CO x , accounting for 96.4%) as the main degradation products. At a concentration of 1 wt%, the PS-MPs exhibited a remarkable conversion rate of 90.6% to CO x , showcasing the degradation performance and oxidation degree of this technology. Finally, the degradation mechanism of PS-MPs combined with the detection results of ROS was suggested. This work demonstrates that DBD plasma is a promising strategy for PS-MPs degradation, with high energy efficiency (8.80 mg/kJ) and degradation performance (98.7% within 1 h), providing direct evidence for the rapid and comprehensive treatment of MP pollutants. [Display omitted] • Atmospheric DBD plasma was applied to the in-situ degradation of PS-MPs. • PS-MPs were efficiently degraded by ROS directly generated in the sample layer. • After 60 min of DBD plasma treatment, the degradation efficiency reached 98.7%. • Melting temperature served as the initiation for the effective degradation of MPs. • At 1 wt%, PS-MPs exhibited a remarkable conversion rate of 90.6% to COx. [ABSTRACT FROM AUTHOR]

• A hybrid DBD plasma-catalysis system is developed for reforming various model tars. • Ni/ZSM-5 shows higher performance than Ni/SiO 2 prepared by thermal fusion method. • Single-ring aromatic hydrocarbons and oxygenates exhibit higher reactivity than PAHs. • Performances of catalysis-alone, plasma-alone and in plasma-catalysis are compared. • Obvious synergy of plasma and catalyst is observed in plasma-catalysis system. Tar formation during biomass gasification is undesirable due to the decreased energy efficiency and increased costs for maintaining downstream equipment. The hybrid non-thermal plasma-catalysis method is considered to be a promising alternative, since it overcomes the disadvantages arising from both catalyst deactivation during catalytic reforming and the formation of undesirable liquid by-products in plasma reforming. SiO 2 - and ZSM-5-supported Ni-based catalysts with different Ni loadings (0.5, 1, 3, and 5 wt%) were prepared by thermal fusion and applied to the steam reforming of toluene. Different characterizations of fresh and spent catalysts including XRD, H 2 -TPR, N 2 adsorption-desorption, SEM, TEM, XPS and TGA were conducted to show the properties of catalysts. The results indicated that Ni/ZSM-5 exhibited better performance than Ni/SiO 2 , due to the increased dispersion of Ni particles and the stronger metal-support interaction of Ni/ZSM-5, which was confirmed by the TEM and H 2 -TPR results. In addition, the performances of the catalysis-only (CatO), plasma-only (PlO), and in-plasma-catalysis (IPC) systems in steam reforming of different model tar compounds including benzene, toluene, furfural, naphthalene, fluorene and pyrene were compared using Ni(5 wt%)/ZSM-5. Obvious synergistic effects between DBD plasma and Ni(5 wt%)/ZSM-5 was observed for syngas production in the IPC system. [ABSTRACT FROM AUTHOR]

Highlights • A DBD plasma method for high concentration SF 6 decomposition is proposed. • NH 3 addition promotes the degradation rate efficiency of SF 6. • Solid by-products are produced and can be recycled. • The production path of the by-product was analyzed. Abstract In this paper, the degradation rate, energy yield and the degradation by-products of SF 6 was studied when different concentrations of NH 3 were added. When NH 3 concentration increased from 0 to 2%, the degradation rate efficiency(DRE) of SF 6 increased from 60% to 97.23% under the flow rate of 50ml/min and 94W input power. The energy yield(EY) reached 4.16g/kWh. In addition, we found that increasing the flow rate to 250ml/min, the DRE decreased to 58.71%, but the EY increased to 12.55g/kWh. The main gas by-products are SOF 2 , SO 2 F 2 , SO 2 , OF 2 , HF and NF 3. When the concentration of initial NH 3 increased, the SO 2 concentration increased while the concentrations of SOF 2 , SO 2 F 2 , SOF 4 decreased. In addition, we found that a pale yellow film formed on the surface of the reactor wall. XPS analysis showed that the solid products were mainly S, NH 3 HF and NH 4 HF 2. The emission spectra show that NH 3 addition can effectively promote the formation of active particles and increase plasma density.The addition of NH 3 can convert some of the sulfur and fluorine into solid products and reduce the production of toxic gases. [ABSTRACT FROM AUTHOR]

Non-thermal plasma technology has great potential in reducing polycyclic aromatic hydrocarbons (PAHs) emission. But in plasma-alone process, various undesired by-products are produced, which causes secondary pollutions. Here, a dielectric barrier discharge (DBD) reactor has been developed for the oxidation of naphthalene over a TiO 2 /diatomite catalyst at low temperature. In comparison to plasma-alone process, the combination of plasma and TiO 2 /diatomite catalyst significantly enhanced naphthalene conversion (up to 40%) and CO x selectivity (up to 92%), and substantially reduced the formation of aerosol (up to 90%) and secondary volatile organic compounds (up to near 100%). The mechanistic study suggested that the presence of the TiO 2 /diatomite catalyst intensified the electron energy in the DBD. Meantime, the energized electrons generated in the discharge activated TiO 2 , while the presence of ozone enhanced the activity of the TiO 2 /diatomite catalyst. This plasma-catalyst interaction led to the synergetic effect resulting from the combination of plasma and TiO 2 /diatomite catalyst, consequently enhanced the oxidation of naphthalene. Importantly, we have demonstrated the effectiveness of plasma to activate the photocatalyst for the deep oxidation of PAH without external heating, which is potentially valuable in the development of cost-effective gas cleaning process for the removal of PAHs in vehicle applications during cold start conditions. [ABSTRACT FROM AUTHOR]

Ozonation and advanced oxidation processes based on photocatalysis (P.C.) and non-thermal plasma generated in a dielectric barrier discharge (DBD) in different gas atmospheres were compared for the degradation and mineralization of 2,4-dichlorophenoxy acetic acid (2,4-D) and 2,4-dichlorophenol (2,4-DCP) in aqueous solutions, using a planar falling film reactor with comparable design. The energetic yields (G 50 ) as measure of the efficiencies of the different methods are for 2,4-D in the order DBD/Ar-Fenton > ozonation > DBD/Ar > P.C.ozonation > DBD/Ar:O 2 ≫ DBD/Air > P.C.oxidation. For 2,4-DCP the order is ozonation ≫ DBD/Ar-Fenton > P.C.ozonation > DBD/Ar > DBD/Ar:O 2 ≫ P.C.oxidation > DBD/Air. The degradation by using ozone is very effective, but it should be noted that the mineralization measured by the total organic carbon (TOC) removal is low. The reason is the formation of stable towards ozone intermediates, especially low chain carboxylic acids. The fate of these intermediates during the degradation with the different methods has been followed and discussed. [ABSTRACT FROM AUTHOR]

Atmospheric pressure dielectric barrier discharge (DBD) plasma is an emerging technique for effective bioaerosol decontamination and is promising to be used in indoor environments to reduce infections. However, fundamental knowledge of the dose and dose-response characteristics of plasma-based disinfection technology is very limited. By examining the single-pass removal efficiency of S. lentus aerosol by in-duct grating-like DBD plasma reactors with varied discharge setups (gap distance, electrode size, number of discharge layers, frequency, dielectric material), it was found that the specific input energy (SIE) could be served as the dose for disinfection, and the efficiency was exponentially dependent on SIE in most cases. The corresponding susceptibility constants (Z values) were obtained hereinafter. Humidity was a prominent factor boosting the efficiency with a Z value of 0.36 L/J at relative humidity (RH) of 20% and 1.68 L/J at RH of 60%. MS2 phage showed a much higher efficiency of 2.66–3.08 log 10 of reduction than those of S. lentus (38–85%) and E. coli (42%–95%) under the same condition. Using SIE as the dose, the performance of plasma reactors in the literature was compared and evaluated. This work provides a theoretical and engineering basis for air disinfection by plasma-based technology. [Display omitted] • Specific input energy (SIE) is proposed as a feasible dose parameter for air disinfection by grating-like DBD plasmas • Humidity is a prominent factor boosting the efficiency with a Z value of 1.68 L/J at the relative humidity of 60%. • MS2 phage has a single-pass efficiency of 2.66–3.08 log 10 , much higher than bacteria (38–95%) under the same condition. [ABSTRACT FROM AUTHOR]

Glyphosate was one of the most widely used herbicides in the world. Remediation of glyphosate-contaminated soil was conducted using atmospheric pressure dielectric barrier discharge (DBD) plasma. The feasibility of glyphosate degradation in soil was explored, and the soil leachate toxicity after remediation was assessed via a seed germination test. The experimental results showed that approximately 93.9% of glyphosate was degraded within 45 min of DBD plasma treatment with an energy yield of 0.47 g kWh −1 , and the degradation process fitted the first-order kinetic model. Increasing the discharge voltage and decreasing the organic matter content of the soil were both found to facilitate glyphosate degradation. There existed appropriate soil moisture to realize high glyphosate degradation efficiency. Glyphosate mineralization was confirmed by changes of total organic carbon (TOC), chemical oxygen demand (COD), PO 4 3− and NO 3 − . The degradation intermediates including glycine, aminomethylphosphonic acid, acetic acid, formic acid, PO 4 3− and NO 3 − , CO 2 and CO were observed. A possible pathway for glyphosate degradation in the soil using this system was proposed. Based on the soil leachate toxicity test using wheat seed germination, the soil did not exhibit any hazardous effects following high-efficiency glyphosate degradation. [ABSTRACT FROM AUTHOR]

This study proposed the fluidization-like dielectric barrier discharge (DBD) plasma for the remediation of lindane contaminated soil and integrated physical and chemical reaction pathway. Soil particle distribution within the reactor was simulated with Euler-Euler and Gidaspow drag models, and a bipolar pulsed power supply was applied to energize the DBD reactor after full fluidized. The effect of soil particles movement on electric features was discussed in terms of voltage waveforms and Lissajous figures. Lindane degradation was found to be related to electrics parameters and soil properties. Soil samples before and after treatment were analyzed by XRD and SEM methods. A 95.98% lindane decomposition and 0.66 mg Lindane /h average reaction rate were obtained with 3 wt% CaO injection by pulse power drove fluidization-like DBD after 32 min treatment. Ozone was proved to play a major role during lindane degrading by plasma. The reaction potential pathway of lindane decomposition contains 4 steps, including dehydrogen, dehydrochlorination, and dechlorination, respectively. [Display omitted] • A fluidization-like DBD was proposed for soil remediation with higher species diffusion efficiency. • Different flow rates and diameters were selected to simulate fluidization state and structure, respectively. • Lissajous figure reflects to the development of plasma with soil presence. [ABSTRACT FROM AUTHOR]

In this paper we focus on the development of a methodology for treatment of carbon tetrachloride utilising a non-equilibrium plasma operating at atmospheric pressure, which is not singularly aimed at destroying carbon tetrachloride but rather at converting it to a non-hazardous, potentially valuable commodity. This method encompasses the reaction of carbon tetrachloride and methane, with argon as a carrier gas, in a quartz dielectric barrier discharge reactor. The reaction is performed under non-oxidative conditions. Possible pathways for formation of major products based on experimental results and supported by quantum chemical calculations are outlined in the paper. We elucidate important parameters such as carbon tetrachloride conversion, product distribution, mass balance and characterise the chlorinated polymer formed in the process. [ABSTRACT FROM AUTHOR]

Highlights: [•] In-package nonthermal plasma treatment of strawberries with pesticide residues. [•] Mixture of azoxystrobin, cyprodinil, fludioxonil and pyriproxyfen employed. [•] Electrical and optical characterisation of plasma. [•] GC-MS/MS reveals successful degradation of pesticides in strawberries. [ABSTRACT FROM AUTHOR]

In the context of spreading Coronavirus disease 2019 (COVID-19), the combination of heating, ventilation, and air-conditioning (HVAC) system with air disinfection device is an effective way to reduce transmissible infections. Atmospheric-pressure non-equilibrium plasma is an emerging technique for fast pathogen aerosol abatement. In this work, in-duct disinfectors based on grating-like dielectric barrier discharge (DBD) plasmas with varied electrode arrangements were established and evaluated. The highest airborne bacterial inactivation efficiency was achieved by 'vertical' structure, namely when aerosol was in direct contact with the discharge region, at a given discharge power. For all reactors, the efficiency was linearly correlated to the discharge power (R2 =0.929–0.994). The effects of environmental factors were examined. Decreased airflow rates boosted the efficiency, which reached 99.8% at the velocity of 0.5 m/s with an aerosol residence time of ~3.6 ms. Increasing humidity (relative humidity (RH)=20–60%) contributed to inactivation efficacy, while high humidity (RH=70%−90%) led to a saturated efficiency, possibly due to the disruption of discharge uniformity. As suggested by the plasma effluent treatment and scavenger experiments, gaseous short-lived chemical species or charged particles were concluded as the major agents accounting for bacterial inactivation. This research provides new hints for air disinfection by DBD plasmas. [Display omitted] • In-duct grating-like DBD disinfectors suitable for HVAC systems were established and evaluated. • The one-pass efficiency reached 99.8% with a pressure drop of < 20 Pa of the system, at the velocity of 0.5 m/s. • Bactericidal efficiency was linearly correlated to the discharge power, regardless of the electrode arrangements. • Gaseous short-lived chemical species or charged particles were major agents accounting for airborne bacteria inactivation. [ABSTRACT FROM AUTHOR]

Highlights: [•] DBD plasma reactors were used to remove pollutants from aqueous solutions. [•] Atrazine, chlorfenvinfos, 2,4-dibromophenol and lindane were studied. [•] First-order degradation kinetics were observed for all the compounds. [•] Degradation by-products were identified by GC–MS. [•] Treatment efficiencies were lower in industrial wastewater than in pure water. [Copyright &y& Elsevier]

Highlights: [•] Benzene was successfully degraded by dielectric barrier/packed-bed discharge plasmas. [•] Different electrode geometry has distinct effect on plasmas oxidation performance. [•] Benzene degradation and energy performance were enhanced when using the coil electrode. [•] The reaction products were well determined by online FTIR analysis. [Copyright &y& Elsevier]

Highlights: [•] A more effective use of DBD was adopted to remove H2S. [•] H2S removal rate was enhanced dramatically due to the synergism between DBD and ACF. [•] The novel reactor exhibited excellent by-products control and performance stabilization. [ABSTRACT FROM AUTHOR]

Abstract: A first-time account of direct, on-line, instantaneous and efficient chemical conversion of gas phase benzene to methane in argon Dielectric Barrier Discharge (DBD) is presented. In the absence of another overt hydrogen-donating source, potency of analogous parents toward methane generation is found to follow the order: benzene>toluene> p-xylene. Simultaneous production of trace amounts of phenolic surface deposits suggest (a) prompt decomposition of the parent molecules, including a large fraction yielding atomic transients (H-atom), (b) continuous and appropriate recombination of such parts, and (c) trace moisture in parent contributing ls and additional H-atoms, which suitably react with the unreacted fraction of the parent, and also other intermediates. Results highlight Ar DBD to be a simple and exploitable technology for transforming undesirable hazardous aromatics to usable/useful low molecular weight open-chain products following the principles of green chemistry and engineering. [Copyright &y& Elsevier]

Abstract: A novel dielectric barrier discharge (DBD) reactor was made for the abatement of xylene. This reactor has a photocatalytic electrode prepared by a modified anodic oxidation method which was proposed in this work. The photocatalytic electrode has nano-TiO2 deposited on sintered metal fiber (SMF). The reactor using the nano-TiO2/SMF electrode shows much better performance in abating xylene compared with reactors using other electrodes such as resistance wire or SMF. The conversion ratio of xylene reaches 92.7% in the novel reactor at a relatively voltage (23.6kV). This ratio is much higher than the conversion ratios of xylene in the traditional reactors with resistance wire or SMF electrodes, which are ∼64.7%. The selectivity of CO2 of the reactor using the nano-TiO2/SMF electrode (300pps, 23.6kV) was observed to be 86.6%, which is about twice as large as that of a traditional reactor using a resistance wire electrode. If a traditional DBD reactor is replaced by the novel reactor, at the same specific input energy, the energy yield can increase from 0.391 to 0.556mg/kJ. Finally, the xylene decomposition mechanism with the nano-TiO2/SMF electrode was also briefly discussed. [Copyright &y& Elsevier]

Abstract: Two lab-scale self-cleaning filters based on dielectric barrier discharges in air at atmospheric pressure have been developed and tested. Experimental results on aerosol removal by charging and electro-collection are presented versus plasma and hydrodynamic parameters for monodisperse aerosol from 20nm to 1.2μm. For classical atmospheric aerosol, the average mass and number filtration efficiencies exceed 95% and 87%, respectively in the most penetrating size range (100–700nm). The frequency of the applied voltage controls the amplitude of the oscillation of charged particle and can be adjusted to favour either filtration or cleaning. Low frequency (1kHz) is suitable for electro-collection, while high frequency (60kHz) is favourable for filter cleaning. Electrical characterization and filter efficiency are two indicators of the filter loading. The durations of both filtration step at maximal efficiency and cleaning step depends on the deposited mass, the surface input power and subsequent dielectric surface temperature. [Copyright &y& Elsevier]

Abstract: Decolorization of reactive textile dyes Reactive Black 5, Reactive Blue 52, Reactive Yellow 125 and Reactive Green 15 was studied using advanced oxidation processes (AOPs) in a non-thermal plasma reactor, based on coaxial water falling film dielectric barrier discharge (DBD). Used initial dye concentrations in the solution were 40.0 and 80.0mg/L. The effects of different initial pH of dye solutions, and addition of homogeneous catalysts (H2O2, Fe2+ and Cu2+) on the decolorization during subsequent recirculation of dye solution through the DBD reactor, i.e. applied energy density (45–315kJ/L) were studied. Influence of residence time was investigated over a period of 24h. Change of pH values and effect of pH adjustments of dye solution after each recirculation on the decolorization was also tested. It was found that the initial pH of dye solutions and pH adjustments of dye solution after each recirculation did not influence the decolorization. The most effective decolorization of 97% was obtained with addition of 10mM H2O2 in a system of 80.0mg/L Reactive Black 5 with applied energy density of 45kJ/L, after residence time of 24h from plasma treatment. Toxicity was evaluated using the brine shrimp Artemia salina as a test organism. [Copyright &y& Elsevier]

Abstract: Dielectric barrier discharge (DBD) was investigated for the simultaneous removal of NO x and SO2 from flue gas in a coal-combustion power plant. The DBD equipment was used in either a mode where flue gas was directed through the discharge zone (direct oxidation), or a mode where produced ozonized air was injected in the flue gas stream (indirect oxidation). Removal efficiencies of SO2 and NO for both methods were measured and compared. Oxidation of NO is more efficient in the indirect oxidation, while oxidation of SO2 is more efficient in the direct oxidation. Addition of NH3, has lead to efficient removal of SO2, due to thermal reaction, and has also enhanced NO removal due to heterogeneous reactions on the surface of ammonium salt aerosols. In the direct oxidation, concentration of CO increased significantly, while it maintained its level in the indirect oxidation. [ABSTRACT FROM AUTHOR]

Abstract: An integrated granular activated carbon (GAC) adsorption/dielectric barrier discharge (DBD) process was applied to the treatment of high concentration pentachlorophenol (PCP) wastewater. The PCP in water firstly was adsorbed onto GAC, and then the degradation of PCP and regeneration of exhausted GAC were simultaneously carried out by DBD. The degradation mechanisms and products of PCP loaded on GAC were analyzed by EDX, FT-IR and GC–MS. The results suggested that the Cin PCP adsorbed by GAC were cleaved by DBD plasma, and some dechlorination and dehydroxylation products were identified. The adsorption capacity of adsorption/DBD treated GAC could maintain relatively high level, which confirmed that DBD treatment regenerated the GAC for subsequent reuse. The adsorption of N2, Boehm titration and XPS were used to investigate detailed surface characterizations of GAC. It could be found that DBD plasma not only increased the BET surface area and pore volume in micropore regions, but also had remarkably impact on the distribution of the oxygen-containing functional groups of GAC. [Copyright &y& Elsevier]

The main target of this work is to characterize the abatements of particulate matter (PM), hydrocarbons (HC) and nitrogen oxides (NO x ) from an actual diesel exhaust using dielectric barrier discharge technology (DBD). The effects of several parameters, such as peak voltage, frequency and engine load, on the contaminant removals have been investigated intensively. The present study shows that for a given frequency, the removals of PM and HC are enhanced with the increase of peak voltage and level off at higher voltage, while in the range of higher voltages a decline of NO x removal efficiency is observed. For a given voltage, the maximums of specific energy density (SED) and removal efficiency are attained at resonance point. The increase of peak voltage will result in a significant decrease of energy utilization efficiency of DBD at most engine loads. Alkanes in soluble organic fraction (SOF) are more readily subjected to removals than polycyclic aromatic hydrocarbons (PAHs). [Copyright &y& Elsevier]

Abstract: Destruction of gaseous benzene (C6H6) by dielectric barrier discharge (DBD) was studied in both laboratory-scale and scale-up DBD systems. The effects of input power, gas flow rate as well as initial concentration on benzene decomposition and energy yield were investigated. In addition, qualitative analysis on byproducts and relatively detailed discussion on mechanisms were also presented in this paper. At last, we systematically illustrated the feasibility of benzene removal with DBD on basis of three aspects: estimation of treatment cost per unit volume, comparison with other plasmas, and problems existed in DBD system. The results will help impel actual application of DBD on waste gas containing benzene. [Copyright &y& Elsevier]

Abstract: Degradation of diuron in aqueous solution was conducted in a dielectric barrier discharge (DBD) reactor and the proposed degradation mechanism was investigated in detail. The factors that affect the degradation of diuron were examined. The degradation efficiency of diuron and the removal of total organic carbon (TOC) increased with increasing input power, and the degradation of diuron by DBD fitted first-order kinetics. Both strong acidic and alkaline solution conditions could improve diuron degradation efficiency and TOC removal rate. Degradation of diuron could be accelerated or inhibited in the presence of H2O2 depending on the dosage. The degradation efficiency increased dramatically with adding Fe2+. The removal of TOC and the amount of the detected Cl−, NO3 − and NH4 + were increased in the presence of Fe2+. The concentrations of oxalic and acetic acids were almost the same in the absence and presence of Fe2+, but high concentration of formic acid was accumulated in the presence of Fe2+. The main degradation pathway of diuron by DBD involved a series of dechlorination-hydroxylation, dealkylation and oxidative opening of the aromatic ring processes. [Copyright &y& Elsevier]

Abstract: We reported on the experimental study of gas-phase removal of ammonia (NH3) via dielectric barrier discharge (DBD) at atmospheric pressure, in which we mainly concentrated on three aspects—influence of initial NH3 concentration, peak voltage, and gas residence time on NH3 removal efficiency. Effectiveness, e.g. the removal efficiency, specific energy density, absolute removal amount and energy yield, of the self-made DBD reactor had also been studied. Basic analysis on DBD physical parameters and its performance was made in comparison with previous investigation. Moreover, products were detected via ion exchange chromatography (IEC). Experimental results demonstrated the application potential of DBD as an alternative technology for odor-causing gases elimination from gas streams. [Copyright &y& Elsevier]

Abstract: A plasma reactor with catalysts was used to treat exhaust gas from a gasoline engine in order to decrease particulate matter (PM) emissions. The effect of non-thermal plasma (NTP) of the dielectric discharges on the removal of PM from the exhaust gas was investigated experimentally. The removal efficiency of PM was based on the concentration difference in PM for particle diameters ranging from 0.3 to 5.0μm as measured by a particle counter. Several factors affecting PM conversion, including the density of plasma energy, reaction temperature, flow rate of exhaust gas, were investigated in the experiment. The results indicate that PM removal efficiency ranged approximately from 25 to 57% and increased with increasing energy input in the reactor, reaction temperature and residence time of the exhaust gas in the reactor. Enhanced removal of the PM was achieved by filling the discharge gap of the reactor with Cu-ZSM-5 catalyst pellets. In addition, the removal of unburned hydrocarbons was studied. Finally, available approaches for PM conversion were analyzed involving the interactions between discharge and catalytic reactions. [Copyright &y& Elsevier]

Cold plasma is considered a highly competitive advanced oxidation process for the removal of organic pollutants from soil. Herein, we describe for the first time the combination of in-soil generated plasma micro-discharges with the advantageous high voltage nanosecond pulses (NSP) towards the high-efficient degradation of trifluralin in soil. We performed a detailed parametric analysis (pulse frequency, pulse voltage, soil thickness, soil type, energy efficiency) to determine the optimum operational conditions. High trifluralin degradation was achieved even at the higher soil thickness, indicating that the production of plasma discharges directly inside the soil pores enhanced the mass transfer of plasma reactive oxygen and nitrogen species (RONS) in soil. The energy efficiency achieved was outstanding, being up to 2–3 orders of magnitude higher than those reported for other plasma systems. We identified the intermediate degradants and proposed the most dominant degradation pathways whereas a thorough exhaust gases analysis, optical emission spectroscopy (OES) and active species inhibition by using trapping agents revealed the main RONS involved. This effort constitutes a significant advancement in the "green" credentials and application of plasma-induced degradation of pollutants as it describes for the first time the removal of the highly harmful and toxic pesticide trifluralin from soil and provides a novel perspective towards the future development of cold plasma-based soil remediation technologies. [Display omitted] • NSP-CAP was used for the first time to degrade trifluralin in soil. • Production of plasma discharges directly inside interconnected pores of soil. • Extremely high energy efficiency of the lab scale in-situ NSP plasma approach. • High-energy electrons and singlet oxygen contribute in pollutant degradation. • Trifluralin degradation mechanism based on OES, exhaust gas analysis and LC/MS. [ABSTRACT FROM AUTHOR]

Oil mist emitted during cooking is one of the major sources of atmospheric particulate matter in urban areas. A conventional electrostatic precipitator (ESP) is used in some large restaurants; it requires regular electrode cleaning to maintain particle collection performance. However, oil mist generated during cooking is viscous and difficult to clean with water. Herein, we introduce a methodology and a device for cleaning collected oil mist using surface dielectric barrier discharge (surface-DBD) plasma. Our device uses corona discharge for the collection of oil mist. Subsequently, the oil mist collected is decomposed to gas-phase species by surface-DBD plasma. A maximum collection efficiency of 93.25% (for 230 nm di-ethyl hexyl sebacate (DEHS) particle) is obtained at a flow velocity of 1.5 m/s. The maximum oil mist decomposition efficiency is 96.4%. More than 80% of the decomposed oil mist is converted to CO 2 and CO under all test conditions. Some of the byproducts other than CO and CO 2 are released as particles. Higher frequency results in higher oil mist decomposition efficiency, but also higher byproduct formation of particles. The mechanism of oil mist decomposition by surface-DBD plasma is discussed using optical emission spectroscopy data. [Display omitted] • Oil mist is electrostatically collected by corona discharge. • Methodology of decomposing collected oil mist using surface-DBD is introduced. • Most of the decomposed oil mist is converted to CO and CO 2. • Some of the byproducts other than CO and CO 2 are released as particles. • Energy for oil mist collection is significantly lower than previous studies. [ABSTRACT FROM AUTHOR]