Dielectric Barrier Discharge System Research Articles

Simultaneous removal of Cr(Ⅵ) and tetracycline from wastewater by dielectric barrier discharge plasma coupled with TiO2/rGO/Cu2O composites: Performance and mechanism

In this study, dielectric barrier discharge (DBD) plasma combined with titanium dioxide/reduced graphene oxide/copper oxide (TiO2/rGO/Cu2O) composites for simultaneous removal of hexavalent chromium (Cr(Ⅵ)) and tetracycline (TC) from wastewater were explored systematically. The TiO2/rGO/Cu2O composites were successfully prepared to improve the specific surface area and charge carrier separation rate. When Cr(Ⅵ) and TC coexist, the two pollutants have better removal efficiency without changing the initial pH. Moreover, the removal efficiency of Cr(Ⅵ) and TC could be further improved in the DBD-TiO2/rGO/Cu2O system, indicating that the TiO2/rGO/Cu2O composites also exhibited good synergistic effects with the DBD plasma. The mechanism exploration showed that the TiO2/rGO/Cu2O composite catalyst could be activated in DBD system to produce various active species by photocatalytic reaction, among which photo-generated electrons and •O2− could significantly enhance Cr(Ⅵ) reduction, while photo-generated holes and •OH could improve TC degradation. More importantly, the intermediate products obtained from TC degradation can be oxidized to •CO2− by photo-generated holes, which can also facilitate the reduction of Cr(Ⅵ). This study shows that DBD combined with TiO2/rGO/Cu2O composites are capable of simultaneous Cr(Ⅵ) reduction and TC degradation, which would provide novel ideas for practical wastewater remediation.

Evolution of the electrical characteristics of an atmospheric pressure dielectric barrier discharge system over one hour operation

In this work, long-time operation of a dielectric barrier discharge (DBD) characterized by a single thin dielectric was investigated. The discharge was operated under nitrogen at atmospheric pressure in a typical filamentary regime. Electrical measurements were performed, i.e. applied voltage, current and charge were retrieved. The Lissajous figure method combined with an equivalent circuit of the DBD was used to calculate the dissipated power, estimate the gas gap voltage , evaluate the deposited charges as well as the capacitances of the discharge cell. The results over a one-hour operation indicated that the total dissipated power remained constant, but a decrease of the gas gap voltage with an increase of the charge deposited was also depicted. For the capacitances, both dielectric and cell capacitances variations were studied from the Lissajous figures. The dielectric capacitance showed a voltage dependency over half a period of applied voltage.

Dielectric barrier discharge plasma-coupled rare-earth modified Er3+-BiOI catalytic materials for degradation of organic pollutant benzohydroxamic acid in mineral beneficiation waster: Performance, degradation pathway, and its mechanism

A dielectric barrier Discharge (DBD) plasma catalytic system for synergistic degradation of benzohydroxamic acid (BHA) was established. A series of Er3+-BiOI samples doped with rare earth elements (Er3+) were prepared by the hydrothermal synthesis method. The characterization showed that Er3+-BiOI had a microglobular structure assembled by nanosheets, and the specific surface area of Er3+-BiOI was larger than that of pure BiOI. The degradation performance showed that in the DBD/Er3+-BiOI system, the highest BHA degradation efficiency reached 96.3 % with 4 % Er3+. Compared with the DBD-BiOI system and the single DBD system, the degradation efficiency of BHA increased by 9.1 % and 17.5 %, respectively. Meanwhile, the kinetic constants and cofactors were also the highest, at 3.36 and 2.88 times the DBD-BiOI system, respectively. The radical capture experiments showed ∙OH, ∙O2−, and cavities play a key role in the degradation of BHA, while O3, H2O2, e−, and H+ promote the degradation of BHA. The intermediates in the degradation of BHA were determined by LC-MS, and the possible degradation pathways of BHA were predicted. Finally, the degradation mechanism of BHA in the DBD/4 % Er3+-BiOI system was proposed.

A novel strategy of peracetic acid activation by dielectric barrier discharge plasma for bisphenol a degradation: Feasibility, mechanism and active species dominant to degradation pathway

As a typical endocrine disruptor, bisphenol A (BPA) can not only affect the reproduction and development of aquatic organisms, but also pose a significant threat to environmental safety and human health. This work proposed a novel strategy of peracetic acid (PAA) activation by dielectric barrier discharge (DBD) plasma for BPA degradation. It can be confirmed that DBD plasma can effectively activate PAA. 93.4 % BPA was destructed in the DBD/PAA system, which was 39.8 % higher than that in the DBD system alone. The energy yield (G50) of the DBD/PAA system was 211.5 g/kWh, while the single DBD system was only 59.7 g/kWh. The degradation efficiencies of chemical oxygen demand (COD) and total organic carbon (TOC) were also improved. The active substances such as OH, CH3C(O)OO, 1O2, O2−, and e− were important for the degradation of BPA in the DBD/PAA system. The pH dropped, and the total conductivity rose in the degradation processing of BPA. Three-dimensional fluorescence spectroscopy, liquid chromatography mass spectrometry (LC-MS) and density functional theory (DFT) simulation were adopted to investigate the degradation mechanism and process. The toxicity of intermediates in three degradation pathways to aquatic organisms was reduced. The degradation efficiency of BPA was more effective as input power increased and initial concentration decreased. BPA was more easily degraded under acidic solutions than under alkaline and neutral solutions. In addition, the effects of typical inorganic ions and humic acids on BPA degradation in the DBD/PAA system were examined. Finally, the DBD/PAA system is suitable for the application of various pollutants and actual wastewater. This research proposes an innovative idea and reference for PAA activation and plasma application in wastewater treatment.

Interactions Between Flow Fields Induced by Surface Dielectric Barrier Discharge Arrays

This study investigates the flow field induced by a surface dielectric barrier discharge (SDBD) system, known for its efficient pollution remediation of volatile organic compounds (VOCs). We aim to understand the flow dynamics that contribute to the high conversion observed in similar systems using this specific SDBD design. Examining how the surface discharge affects the gas mixing in chemical processes is important for both understanding the fundamentals and for potential industrial applications. Experimental techniques, including schlieren imaging and particle image velocimetry (PIV), applied with high temporal resolution, were used to analyse the flow field. Complementary, fluid simulations are employed to investigate the coupling between streamer and gas dynamics. Results show distinct fluid field behaviours for different electrode configurations, which differ in geometric complexity. The fluid field analysis of the most basic electrode design revealed behaviours commonly observed in actuator studies. The simulation results indicate the local information about the electron density as well as different temporal phases of the fluid flow velocity field containing the development of the experimental found vortex structure, its direction and speed of rotation. The electrode design with mostly parallel grid line structures exhibits confined vortices near the surface. In contrast, an electrode design also used in previous studies, is shown to promote strong gas transport through extended vortex structures, enhancing gas mixing and potentially explaining the high conversion observed.

Effect of Dielectric Barrier Discharge Cold Plasma on the Bio-nanocomposite Film and its Potential to Preserve the Quality of Strawberry under Modified Atmosphere Packaging

The present study aimed to investigate the effect of cold plasma on the developed bio-nanocomposite film. A dielectric barrier discharge system was utilized to generate the cold plasma. The films were treated under three different times (5, 10 and 15 min) and the characteristics of the films were evaluated. The cold plasma treatment influence the thermal stability and crystallization of the films. Results showed that the mechanical properties (tensile strength and elongation at break), water vapor permeability, oxygen transmission rate, moisture content and water contact angle characteristics were improved up to 69%, 31%, 34%, 3% and 28%, respectively by cold plasma treatment. In consequence, the average O2 and CO2 concentration of the packed strawberries decreased from 5 and 10% to 4.2% and 5.1%, respectively after 15 days. Finally, the results revealed that the mechanical properties, chemical attributes, physical characteristics and microbial activities of the samples were affected by the treated films. As a result, cold plasma modification can be applied as an effective method to maintain and preservation of fresh fruit.

Synthesis of nucleus-satellite like Ag nanoparticles based on dielectric barrier discharge system for prolonged chemiluminescence imaging of mercury ions

Noble metal nanomaterials were unique in the field of chemiluminescence (CL) because of their high catalytic activity and surface plasmon resonance (SPR). Herein, polyhedral oligomeric silsesquioxanes modified silver nanoparticles (POSS-Ag NPs) were firstly synthesized by dielectric barrier discharge system within 40 min. Amino modified POSS (AE-POSS), as both a reducing agent and protective agent, was bonded to the surface of Ag NPs to stabilized Ag NPs through the three-dimensional framework structure to form “nucleus-satellite” like structures, which specially showed enhanced CL intensity due to increased specific surface area and SPR characteristics. Subsequently, a prolonged CL signal for over 1 h by POSS-Ag NPs - luminol system happened, which could be well observed in the CL imaging. The presence of Ag0/Ag+ and O2/·O2– charge cycling transfer on the surface of POSS-Ag NPs continuously provided large amounts of catalysts (Ag0) and CL reactants (Ag+), continuously reacting with luminol to greatly prolong the CL reaction time. Significantly, due to the mercury (Hg)-Ag alloys production in Ag NPs solution to inhibit catalytic and SPR effects, this intense and long-time CL system for the specific imaging detection of Hg2+ was developed. The detection limit of this method was 3 × 10−8 M. The enhanced prolonged CL phenomenon could improve the accuracy of chemical analysis and have promising applications in CL imaging.

Tailored design of 2D MOF derived carbon boosting the low temperature plasma catalysis for water treatment: The role of graphitization and hierarchical porous structure

The application of efficient and non-polluting low-temperature plasma technology to address the growing problem of environmental pollution has received increasing attention in recent years. In this study, two-dimensional (2D) Co-ZIF (Co-ZIF-L) derived hollow carbon nanosheets (Co-HCNSs) with high graphitization rate and high porosity were designed. The advantages of structure and composition endow Co-HCNSs-9 with excellent catalytic properties. To verify the effects of graphitization and hollow structure, Co-ZIF-L derived solid carbon nanosheets (SCNSs-9) and Zn-ZIF-L derived hollow carbon nanosheets (Zn-HCNSs-9) were prepared in parallel. In low-temperature plasma applications, the degradation rate of tetracycline (TTCH) was as high as 97% within 30 min, Co-HCNSs-9/dielectric barrier discharge (DBD) system improved the degradation rate of TTCH and the energy efficiency The degradation mechanism of Co-HCNSs-9/DBD was investigated by quenching experiments as a synergistic effect of hydroxyl radicals (OH), singlet oxygen (1O2) and reactive nitrogen species (RNS). In addition, the effects of common anions and natural macromolecular organic compounds in the water column were investigated. Based on 3D fluorescence analysis, liquid chromatography-mass spectrometry and density functional theory calculations, possible degradation pathways of TTCH were proposed. Finally, the safety and environmental friendliness of the system was verified by biological toxicity tests.

DBD plasma coupling MnO2-Fe3O4-cellulose acetate films for sulfamethoxazole degradation: Insight for catalytic ozonation and Fenton effect

In this study, efficient degradation of sulfamethoxazole (SMX) by coupling dielectric barrier discharge (DBD) plasma and MnO2-Fe3O4-cellulose acetate (MnO2-Fe3O4-CA) film catalyst was investigated. SEM, XRD, FT-IR and XPS were carried out to confirm the successful preparation of the MnO2-Fe3O4-CA film. The optimal constitution of MnO2-Fe3O4 and CA was evaluated according to the SMX degradation under different conditions of the prepared films. When 3 % 3:1 MnO2-Fe3O4-CA films were added into the DBD system, the removal rate of SMX could reach 93.55 %. Experiments on the effect of the initial pH value of the solution indicated that the SMX degradation was better under both neutral and alkaline solution conditions. Mechanism analysis show that ·OH, ·O2− and 1O2 were involved in the degradation of SMX. The MnO2-Fe3O4-CA catalyst could burst Fenton reaction and promote ozone decomposition, and accordingly generated more reactive oxygen species (ROS) responsible for the increase of the SMX degradation. The cyclic experiments showed that film had good repeatability and stability. Four routes of SMX degradation were given according to the byproducts analysis, and the toxicity was evaluated.

Insights into catalyst-free, highly effective degradation of pharmaceutical contaminant in aqueous solution by a dielectric barrier discharge system

The emerging pharmaceutical wastewater including non-steroidal anti-inflammatory drugs has posed a serious threat to the ecological environment and human health, and therefore effective treatment technologies are being urgently needed. Herein, a novel horizontal continuous-flow dielectric barrier discharge (DBD) system without catalyst was developed for the highly effective degradation of diclofenac in aqueous solution. The degradation efficiency of 10 mg/L diclofenac reached about 90% in 14 min, and the corresponding energy efficiency was 0.181 g/kWh. Furthermore, the treated water quality was evaluated in terms of TOC, BOD5/COD and toxicity. The biodegradability rapidly improved with the increasing of DBD treatment time as be expected, although the mineralization efficiency of diclofenac was still low. To gain insight into the degradation mechanism, short-lived transient and long-lived species have been identified during DBD process, in which transient species (·OH, ·O2–) were the major contribution to the oxidation of diclofenac. Furthermore, based on the intermediates identified by LC-MS, a possible degradation pathway of diclofenac by DBD system in aqueous solution was proposed. Therefore, the novel DBD reactor with horizontal continuous-flow appears to be more promising for the treatment of pharmaceutical wastewater in practical applications.

Controllable and tunable plasma photonic crystals through a combination of photonic crystal and dielectric barrier discharge patterns

We report five types of patterns with square symmetry, including three novel types obtained by inserting a specially designed grid photonic crystal (PC) into a dielectric barrier discharge system. They are studied using an intensified charge-coupled device camera and photomultiplier tubes. The three novel types of patterns are a square pattern with one structure, a square superlattice pattern with four sublattices and a (1/4)K grid (K grid is the basic wave vector of the grid), and another square pattern with a complex inversion discharge sequence. From the application viewpoint, the five types of patterns can be used as plasma photonic crystals (PPCs). Their band diagrams under a transverse-magnetic wave simulated by the finite element method show that there are a large number of band gaps. Compared with the original PC with only a unidirectional band gap, the five types of PPCs have tunable and omnidirectional band gaps, which is very important in controlling the propagation of electromagnetic waves in the mm-wave region. The experimental results enrich the pattern types in the dielectric barrier discharge system and provide a method for obtaining PPCs with symmetry controllability and bandgap tunability.

Characteristics of Double-Layer, Large-Flow Dielectric Barrier Discharge Plasma Source for Toluene Decomposition

The direct decomposition of toluene-containing humidified air at large flow rates was studied in two types of reactors with dielectric barrier discharge (DBD) features in ambient conditions. A scalable large-flow DBD reactor (single-layer reactor) was designed to verify the feasibility of large-flow plasma generation and evaluate its decomposition characteristics with toluene-containing humidified air, which have not been investigated. In addition, another large-flow DBD reactor with a multilayer structure (two-layer reactor) was developed as an upscale version of the single-layer reactor, and the scalability and superiority of the features of the multilayer structure were validated by comparing the decomposition characteristics of the two reactors. Consequently, the large-flow DBD reactor showed similar decomposition characteristics to those of the small-flow DBD reactor regarding applied voltage, flow velocity, flow rate, and discharge length, thus justifying the feasibility of large-flow plasma generation. Additionally, the two-layer reactor is more effective than the single-layer reactor, suggesting multilayer configuration is a viable scheme for further upscaled DBD systems. A high decomposition rate of 59.5% was achieved at the considerably large flow rate of 110 L/min. The results provide fundamental data and present guidelines for the implementation of the DBD plasma-based system as a solution for volatile organic compound abatement.

The enhancing energy efficiency of sulfadiazine degradation using a DBD-contact plasma treatment process

Nonthermal plasma has attracted extensive attention because of its ability to remove emerging organic micropollutants. However, its high amount of energy consumption severely limits its economic feasibility. In this study, sulfadiazine degradation was achieved in an optimized dielectric barrier discharge (DBD)-Contact system. The sulfadiazine removal in the DBD-Contact/peroxymonosulfate (PMS) system reached 91.8% within 15 min. Compared to a conventional DBD system, the energy efficiency (G50) of the DBD-Contact/PMS system was 4.37 times greater, which meant a saving of 77.17% in electricity consumption. The reactive species generated by discharge plasma were identified as mostly excited nitrogen species in the gas phase, and after transferred to the water phase, OH and SO4− played an important role in the sulfadiazine removal. The hydroxylation of the S-N bond and the nucleophilic reaction of the pyrimidine ring were proposed as mechanisms for the sulfadiazine degradation, and the developmental and acute toxicity was significantly reduced after treatment. Furthermore, the DBD-Contact/PMS system showed good applicability in a wide pH range and complex practical water samples. This study finds that the DBD-Contact/PMS system can degrade antibiotics with high efficiency and low energy consumption and provides new insights for the practical application of DBD technology in water treatment.

Plasma-Assisted Priming: Improved Germination and Seedling Performance of Papaya

Papaya is a one of the important tropical fruit crops with a global export of 353 ktonnne reported in 2020. The germination of papaya seed is erratic and often non-uniform. Plasma assisted priming of seed was performed at atmospheric pressure in a parallel plate dielectric barrier discharge system. The germination rate of papaya seeds and the growth performance of the seedling were monitored for several treatment plans combining the atmospheric pressure plasma treatment with soaking of seed in deionized water. An enhanced germination rate of 92% was obtained by the plasma assisted priming, compared to the untreated of 60%. The plasma assisted priming performed by plasma treatment and soaking in an opposite sequence showed different requirement and possibly involved different mechanisms. The treatment time was reduced to only 4 minutes for pre-soaked seeds, otherwise the germination rate increased with the plasma treatment time from 3 to 30 min treatment. The plasma assisted priming approaches were also found enhancing seedling growth performance. The treated seedling grows about two times bigger and the dried mass measured after 30 days was more than 100% compared to that of the untreated and hot water treated seeds.

Preparation and evaluation of high-transparent scratch-resistant thin films on plasma treated polycarbonate substrate

New simple aqueous sol–gel procedure has been used for producing hard transparent organic–inorganic coatings on polycarbonate (PC). Sol-gel thins films were prepared by mixing Si and Al aqueous alkoxides and applied on the plasma treated PC. Tetraethyl orthosilicate (TEOS), 3-glycidoxypropyltrimethoxysilane (GPTMS) and aluminum tri sec-butoxide were used as main precursors. Before applying coatings PC were treated by Dielectric Barrier Discharge (DBD) system being conducted at atmosphere pressure. The effects of temperature, sols volume ratios and aging time on the coatings properties were scrutinized. Chemical, structural, morphological, optical and mechanical analyses of the samples were done by ATR-FTIR, EDS, XRD, FE-SEM, TEM, UV/vis spectroscopy, ellipsometry, pencil hardness and eraser scratch methods. TEM results showed well-dispersed nano-particles in the liquid sol. All of the films showed higher average transmittance (89 %) than the raw PC (86 %) that was stemmed from the lower refractive index (1.481) than raw PC (1.58). Films indicated good adhesion onto the plasma treated substrates (5B). The pencil hardness of the PC substrate (4B) improved to 3H (8 pencil grade increment) with just a single layer coating (775 nm thickness) due to the preparation of new hard structures of interlocked Si and Al atoms.

Dielectric barrier discharge plasma for the remediation of microplastic-contaminated soil from landfill

The huge amount of plastic waste accumulated in landfills has caused serious microplastic (MP) pollution to the soil environment, which has become an urgent issue in recent years. It is challenging to deal with the non-biodegradable MP pollutants in actual soil from landfills. In this study, a coaxial dielectric barrier discharge (DBD) system was proposed to remediate actual MP-contaminated landfill soil due to its strong oxidation capacity. The influence of carrier gas type, applied voltage, and air flow rate was investigated, and the possible degradation pathways of MP pollutants were suggested. Results showed the landfill soil samples contained four common MP pollutants, including polyethylene (PE), polypropylene (PP), polystyrene (PS), and polyvinyl chloride (PVC) with sizes ranging from 50 to 1500 μm. The MP pollutants in the soil were rapidly removed under the action of reactive oxygen species (ROS) generated by DBD plasma. Under the air flow rate of 1500 mL min−1, the maximum remediation efficiency represented by mass loss reached 96.5% after 30 min treatment. Compared with nitrogen, when air was used as the carrier gas, the remediation efficiency increased from 41.4% to 81.6%. The increased applied voltage from 17.5 to 24.1 kV could also promote the removal of MP contaminants. Sufficient air supply was conducive to thorough removal. However, when the air flow rate reached 1500 mL min−1 and continued to rise, the final remediation efficiency would be reduced due to the shortened residence time of ROS. The DBD plasma treatment proposed in this study showed high energy efficiency (19.03 mg kJ−1) and remediation performance (96.5%). The results are instructive for solving MP pollution in the soil environment.

Oxidation of ciprofloxacin by the synergistic effect of DBD plasma and persulfate: reactive species and influencing factors analysis

A synergistic system of water falling film dielectric barrier discharge (DBD) plasma and persulfate (PS) was set up and used for oxidizing ciprofloxacin (CIP) in water. Results of reactive species formation in the DBD-only system as well as the DBD–PS system verified the PS activation in the DBD system. Influencing factors on CIP degradation and the degradation process were also been studied. The obtained results showed that the presence of PS could greatly improve the degradation and mineralization of CIP and that the degradation efficiency could reach 97.73% after only 40 min treatment with 4 mM PS addition. The increase of PS concentration, the lower CIP concentration, the acidic solution pH and the addition of metal ions (Fe2+ and Cu2+) enhanced the CIP degradation, while the existence of Cl− and HC had a negative effect. The experiments related to scavenger addition confirmed the contribution of the main reactive species to the CIP oxidation. Three probable degradation pathways were proposed by analyzing the inorganic ions and organic byproducts formed during the CIP degradation. The toxicity evaluation results of the CIP and its intermediates confirmed the effectiveness of the DBD–PS synergistic system.

Correction: A scalable twin surface dielectric barrier discharge system for pollution remediation at high gas flow rates

Correction for ‘A scalable twin surface dielectric barrier discharge system for pollution remediation at high gas flow rates’ by Alexander Böddecker et al., React. Chem. Eng., 2022, 7, 2348–2358, https://doi.org/10.1039/D2RE00167E.

The impact of cold plasma innovative technology on quality and safety of refrigerated hamburger: Analysis of microbial safety and physicochemical properties

Atmospheric cold plasma (ACP) is an innovative non-thermal decontamination technology that is considered a great alternative to conventional preservation methods. Most importantly, improving microbial safety along with maintaining the sensory and quality properties of the treated foods, especially for perishable products. Hence, this study aimed to investigate the antimicrobial effects of novel dielectric barrier discharge (DBD) and Jet cold plasma systems and their impact on the physicochemical, color, and sensory properties of refrigerated hamburger samples. In the current study, hamburger samples were inoculated with Staphylococcus aureus, Escherichia coli, Molds and Yeasts microbial suspension (~106 CFU/mL), and then were treated with argon (Ar), helium (He), nitrogen (N), and atmosphere (Atm) gases at different times (s) (0, 30, 60, 90, 180, 360). Similarly, uninoculated samples were considered for total viable count (TVC) testing. The results exhibited that plasma system type, gas type, and treatment time had a significant antimicrobial effect with a microbial reduction ranging from 0.01 to 2 log CFU/g and 0.04–1.5 log CFU/g for DBD and Jet plasma systems, respectively. Also, a treatment time longer than 90 s for DBD and 180 s for jet resulted in a significant reduction in microbial count. The ability of atmospheric cold plasma to inactivate tested foodborne pathogenic bacteria (E. coli and S. aureus) was stronger than other gases because the concentration of O3 and NO gases in atmospheric plasma is higher than other used plasma gases. Surface color measurements (L*, a* and b*) of samples in both methods (DBD and Jet) were not significantly affected. Moreover, samples treated with various plasma gases have indicated insignificant oxidation changes (Thiobarbituric acid assay). These outcomes can assist to reduce microbial contamination and oxidation of hamburgers as a high-consumption and perishable product using ACP technology. Owing to the non-thermal nature of ACP, samples treated with ACP have exhibited no or least effects on the physical, chemical, and sensory features of various food products. As a result, cold plasma innovative technology can be proposed and used as an efficient preservative method to increase the shelf life of food products.

ZnCo2O4 composite catalyst accelerated removal of phenylic contaminants containing of Cr(VI) in dielectric barrier discharge reactor: Process and mechanism study

The degradation of phenylic contaminants (phenol, hydroquinone, nitrobenzene, p-nitrophenol) containing Cr(VI) has been investigated in a dielectric barrier discharge (DBD) system using a ZnCo2O4 composite catalyst. The ZnCo2O4 nanowires combined with multi-walled carbon nanotubes (MWNTs) on a sponge substrate in the discharge system can induce a decrease in the corona inception voltage and discharge becomes more stable resulting in an improvement in the energy utilization efficiency. With the synergistic degradation of phenylic species containing Cr(VI), the total elimination efficiency was further improved. The active substances (H2O2 and O3) were detected in the discharged solution, and some of them were consumed in the phenylic system. The effects of ·OH, O2·- and e− were also verified using free radical trapping experiments in which ·OH exhibited the main oxidation effect for the degradation of phenylic pollutants, and e−, H2O2 and H· affect the reduction of Cr(VI). The intermediate products were determined in order to analyze the degradation process of phenylic pollutants by the ZnCo2O4 composite catalyst in combination with the DBD system. The electron transfer process in the ZnCo2O4 composite catalyst during discharge was analyzed. Finally, the biotoxicity of the phenylic pollutants before and after degradation was compared.