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Oil drilling cuttings produced during oil exploration and extraction contain a high percentage of crude oil, ranging from 5% to 20% weight ratio (w/w) on a dry basis, and must be managed and treated properly before their release to the environment. In this study, non-thermal plasma (NTP) was investigated as an advanced oxidation process for the efficient, sustainable and cost-effective treatment of oil drilling cuttings. To this end, a plane-to-grid dielectric barrier discharge (DBD) reactor operating at atmospheric pressure was tested under different plasma conditions. The effect of treatment time, DBD power and air flow rate on the total organic carbon (TOC) removal efficiency was assessed and the energy efficiency of the process was determined. Within 10 min of plasma treatment, a very high TOC and total petroleum hydrocarbons (TPH) removal (∼90% and ∼99%, respectively) was achieved, while polycyclic aromatic hydrocarbons (PAHs) were degraded by ∼50% within 2 min of treatment. Depending on the experimental conditions, the energy efficiency of the process varied from 5 to 35 mg/kJ. From GC-MS analysis, several byproducts of the oxidation of oil drilling cuttings were identified, while the analysis of exhaust gases revealed that ∼85.1% of the removed organics from oil drilling cuttings was transformed to CO 2 and CO. This study provides critical information on the effectiveness of the NTP process for the treatment of heavily contaminated solid wastes and can be considered as the critical step for its application for the treatment of solid wastes from the oil industry. [Display omitted] [ABSTRACT FROM AUTHOR]

This study deals with the surface modification of polymer films utilizing a custom designed cost- effective dielectric barrier discharge (DBD) plasma produced in air at reduced pressure. We comprehensively examine diverse aspects of surface modification, encompassing electrical discharge characterization, optical signal analysis, contact angle measurements, and surface morphology assessment. Our observations unveiled the presence of distinctive filamentary streamer-based micro-discharges during the DBD process, with a power consumption of approximately 5.64 W and an electron density of 3.4 × 1011 cm−3. Optical emission spectroscopy identifies multiple emission peaks attributed to nitrogen emissions. Notably, plasma treatment substantially reduced the water contact angle and augmented surface energy on polypropylene (PP) and polyethylene terephthalate (PET) films. Surface morphology analysis illustrated an increase in surface roughness following plasma treatment. Intriguingly, the initial rapid alterations in wettability and surface morphology attained equilibrium after approximately 30 s of treatment. This study highlights atmospheric DBD plasma's effectiveness in customizing polymer surfaces, improving wettability and roughness, offering promising applications for enhanced adhesion and wetting.

Elemental mercury (Hg0) removal is a crucial target for mercury pollution control in flue gas. This article focuses on Hg0 removal in flue gas using corona discharge (CD) and dielectric barrier discharge (DBD) technologies, and provides a mechanistic perspective on the development and influencing factors of non-thermal plasma (NTP) technology for Hg0 removal. The influence factors include reactor configurations, power supplies, energy density, residence time, oxidation methods, gas composition, and the synergy between NTP and catalysis/adsorption, etc. This study reveals that the use of a pulsating electrical power supply significantly increases electron densities in both CD and DBD systems, thereby ensuring high energy efficiency and economic viability. Cl 2 proves to be more effective than HCl as a chlorine source for Hg0 removal. NO significantly reduces Hg0 oxidation efficiency, while the effects of SO 2 and H 2 O remain unclear. Energy density distribution is closely related to plasma devices, power supplies, and overall reactor configurations. Direct oxidation proves to be more effective than indirect oxidation for Hg0 removal. The combination of NTP with adsorption/catalysis technologies shows significantly better Hg0 removal efficiency compared to using NTP alone. This study can provide theoretical support for enhancing Hg0 removal mechanisms and optimizing process control parameters in industrial applications of NTP technology. [Display omitted] • Non-thermal plasma (NTP) can effectively remove Hg0 from flue gas. • Insights into the mechanism of flue gas Hg0 removal are offered. • NTP with chemical catalysis/adsorption shows higher Hg0 removal efficiency. [ABSTRACT FROM AUTHOR]

This study investigates experimentally the effects of non-thermal plasma (NTP) induced by a dielectric barrier discharge (DBD) reactor on the characteristics of swirl-stabilized turbulent lean-premixed methane/air flames in a laboratory scale combustor by systematically varying the applied AC voltage, V AC , and frequency, f AC. Especially, it is elucidated how the NTP influences the lean blowout (LBO) limits and the characteristics of CO/NO x emissions depending on flame configuration. Without applying the NTP as the mixture equivalence ratio, ϕ , decreases from the stoichiometry to an LBO limit, the flame configuration changes from an M-flame (Regime I) to a conical flame (Regime II) and to a columnar flame (Regime III) for the whole range of the mixture nozzle exit velocity, U 0 , (4–10 m/s). With the NTP, however, it exhibits only Regimes I and II at relatively-low U 0 range (4–6 m/s), while all three regimes at relatively-high U 0 range (7–10 m/s). For both velocity ranges, the LBO limits are significantly extended by the NTP enhancing the flame stability. Under the relatively-low U 0 range, streamers induced by the DBD reactor play a critical role in stabilizing the flames such that the degree of extension of the LBO limit depends linearly on V AC and f AC. Under the relatively-high U 0 range, however, ozone generated by the DBD reactor in Regime III is found to be a major reason in extending the LBO limit, which is substantiated by another flame regime diagram with ozone addition only, and hence, the extension of LBO limit minimally depends on f AC. Simultaneously, the NTP considerably reduces CO emission, while slightly increases NO x emission near the LBO limits due to the enhanced combustion by ozone. [ABSTRACT FROM AUTHOR]

Trickle-bed DBD reactor with ceramic foam packing to enable the liquid film degradation of tetracycline hydrochloride. [Display omitted] • Trickle-bed plasma reactor was developed for degrading tetracycline hydrochloride (TCH). • High degradation efficiency was obtained in system with ceramic foam packing. • Liquid film promotes plasma discharge and mass transfer of active species. • Active species (especially O 2 ·−) play the major role in TCH degradation. Non thermal plasma (NTP) is a promising technology for degrading organic pollutants in water/wastewater, in which the transfer of energetic species at the interface between gas discharge and liquid phase is key to improve degradation efficiency. Herein, this work shows the development of an integrated system of dielectric barrier discharge (DBD) plasma and open-cell ceramic foam (CF) for the degradation of tetracycline hydrochloride (TCH, a model antibiotic) in liquid film. Specifically, a bespoke trickle-bed DBD reactor with liquid distributor was developed to enable the formation of uniform liquid film on the surface of the hydrophilic CF strut. Due to the improved mass transfer across the thin liquid film, the trickle-bed DBD reactor with the hydrophilic CF exhibited the comparatively highest TCH removal efficiency (>80%) and energy efficiency (viz., EE TCH removal of ∼0.6 g kWh−1) among the systems under investigation such as the glass bead packed DBD. The findings showed that the presence of liquid film was beneficial to the propagation of homogeneous plasma discharge in the CF bed and promoted the mass transfer of active species from plasma discharge to liquid, and thus improved the TCH degradation efficiency. Results from quenching experiments suggested that the electron induced active species (especially O 2 −) played the important role in degrading TCH rather than electrons. [ABSTRACT FROM AUTHOR]

Methyl parathion (MP) as an organophosphorus pesticide has been used in the control of agricultural pests and diseases. Due to its high toxicity and persistence in the environment, MP may pose threat to human health when it is released into environmental water. For MP treatment, people have found that oxidative degradation of MP may generate some intermediates which are more toxic than MP itself, such as methyl paraoxon. Herein, we proposed a new method of applying dielectric barrier discharge (DBD) non-thermal plasma technology to treat MP in aqueous solution, and investigated the influences of different gases, pH value, discharge voltage/power, and main active species on the MP removal efficiency. In particular, the safety of DBD treatment was concerned with analysis of the biological toxicity of the byproducts from the DBD oxidation, and the DBD-induced degradation together with the involved mechanism was explored therein. The results showed that the production of toxic intermediates could be effectively suppressed or avoided under certain treatment conditions. As such, this work demonstrates that the proper application of DBD plasma technology with necessary caution can detoxify methyl parathion effectively, and also provides a practical guide for low-temperature plasma application in treatment of various organophosphorus pesticides in agricultural wastewater. [Display omitted] • Efficient detoxification of methyl parathion by dielectric barrier discharge (DBD) plasma was explored. • The comprehensive DBD induced degradation pathways and mechanisms were scrutinized. • Biotoxicity evaluation on various DBD degradation intermediates was provided. • This work may give a guide to efficient and safe application of plasma in pesticide treatment. [ABSTRACT FROM AUTHOR]

Experimental results of non-thermal plasma (NTP) utilization for degradation of 4-chlorphenol (4CP) with screening of toxicity were presented in this study. Degradation of 4CP was tested in the presence of homogeneous catalysts: hydrogen peroxide (H 2 O 2 ) and iron (II) (Fe 2+ ). The rate of degradation through eight consecutive passes of the 4CP solution in the NTP reactor was considered. Products of degradation as organic acids (acetic, formic or oxalic acid) and chloride were quantified using ion chromatography (IC). Artemia salina was used for the toxicity screening assay in order to estimate the potential and consequences of NTP reactor application in water treatment. The measured concentration of 4CP and degradation products confirmed very efficient removal of these substances from the water during the NTP treatment with the addition of a catalyst. Concerning bioassay, a significant difference in toxicity was determined between initial solution of 4CP in comparison with the solution exposed to catalytic NTP treatment. [ABSTRACT FROM AUTHOR]

The effects of non-thermal plasma (NTP) induced by a dielectric barrier discharge (DBD) reactor on the stability of turbulent lean and rich premixed ammonia/air flames and the NO x emission characteristics in a modified model gas turbine combustor are experimentally investigated by varying the applied AC voltage, V AC , frequency, f AC , and the mean mixture velocity, U 0. Applying NTP to ammonia/air flames augments the flame stability such that the stable flame regime is extended to lower equivalence ratio, ϕ , under fuel-lean conditions or higher ϕ under fuel-rich conditions. NTP is found to significantly reduce the amount of NO x emission for both lean and rich premixed ammonia/air flames and the amount of NO x emission is well correlated with V AC ⋅ f AC ⋅ U 0 − 1 . The reduction of NO x emission through NH 2 reactions is also identified by measuring NH 2 ∗ chemiluminescence. • Non-thermal plasma (NTP) significantly enlarges the blowout limits of ammonia/air flames. • NO x emission can be significantly reduced by applying NTP and by decreasing the flow residence time. • NTP reduces NO x emission by generating more NH 2. [ABSTRACT FROM AUTHOR]

The use of non-thermal plasma (NTP) generators in air processing systems and their duct networks to improve indoor air quality (IAQ) has grown considerably in recent years. This paper reviews the advantages and disadvantages of NTP generators for IAQ improvement in biological, chemical and particulate pollutant terms. Also, it assesses and compares the ability of a multipin corona discharge (MPCD) and a dielectric barrier discharge (DBD) generator to reduce the concentration of fine particulate matter (PM2.5) in recycled, unfiltered air in a refrigeration chamber. The MPCD generator was found to have a higher PM2.5 removal efficiency; also, it was faster in removing pollutants, used less energy, and produced much less ozone. The fact that the MPCD generator performed better was seemingly the result of its increased ion production mainly. NTP generators, however, cannot match air filtration media purifiers in this respect as the latter are much more effective in removing particles. Besides, NTP-based air purifying technology continues to be subject to a major drawback, namely: the formation of ozone as a by-product. In any case, the ozone generation was uncorrelated to ion emission when using different technologies. • Non-Thermal Plasma technology is becoming more popular in indoor air management. • Non-Thermal Plasma technology is able to remove various pollutants from the air. • Corona and dielectric barrier discharge are technologies used to generate cold plasma. • Multipin Corona Discharge shows better efficiency removing fine particles than Dielectric Barrier Discharge. • Ozone still being a problem in the use of Non-Thermal Plasma systems. [ABSTRACT FROM AUTHOR]

Polychlorinated biphenyls (PCBs) are a kind of persistent organic pollutants (POPs) with stable chemical properties which can be enriched in a biological body for a long time. They are often carelessly released into natural environment and thus constantly posing a potential threat to human health. However, because of lack of effective ways of degrading PCBs, researchers are still striving to explore new approaches to remove them from the environment. In this work, we employed atmospheric-pressure non-thermal dielectric barrier discharge (DBD) plasma to treat 3,3′,4,4′-tetrachlorobiphenyl (PCB77) in aqueous solution and investigated the removal efficiency under different DBD conditions using different discharging gases. As a result, we showed that He-DBD had the highest removal efficiency with hydroxyl radical playing the major role in the degradation, while O 2 -DBD also gave rise to relatively high efficiency with ozone making an important contribution. After 2 min of treatments by He-DBD and O 2 -DBD, over 75% of PCB77 was degraded with removal rate of 23.65 mg/L and 22.19 mg/L per minute, respectively. Besides, the toxicological evaluation for the DBD treatment was also provided, confirming that the PCB77 degradation products had negligible biotoxicity. This work therefore provides a new effective approach to treatment of persistent organic pollutants (POPs) in the environment. Unlabelled Image • Atmospheric-pressure non-thermal DBD plasma is used to degrade PCB. • He-DBD, O 2 -DBD and air-DBD can remove PCB77 efficiently. • Combined roles of hydroxyl radical, ozone, UV and H 2 O 2 are verified. • Degradation pathways and mechanism are investigated and clarified. [ABSTRACT FROM AUTHOR]