Degradation Of Phenol In Wastewater Research Articles

Iron-bearing mining reject as an alternative and effective catalyst for photo-Fenton oxidation of phenol in water.

In this work, iron-bearing mining reject was employed as an alternative and potential low-cost catalyst to degrade phenol in water by photo-Fenton strategy. Various techniques, including SEM-EDS, BET, FTIR, and XRD, were applied to evaluate the material's properties. Process parameters such as hydrogen peroxide concentration, catalyst dosage, and pH were studied to determine the optimum reaction conditions ([catalyst] = 0.75g L-1, [H2O2] = 7.5mM, and pH = 3). Phenol degradation and mineralization efficiencies at 180 and 300min were 96.5 and 78%, respectively. These satisfactory results can be associated with the iron amount present in the waste sample. Furthermore, the material showed high catalytic activity and negligible iron leaching even after the fourth reuse cycle. The degradation behavior of phenol in water was well represented by a kinetic model based on the Fermi function. The iron-bearing mining reject can be considered a potential photo-Fenton catalyst for phenol degradation in wastewater.

Degradation of phenol in wastewater through an integrated dielectric barrier discharge and Fenton/photo-Fenton process

In this study, a non-thermal dielectric barrier discharge-Fenton/photo-Fenton process was investigated to remove phenol from synthetic wastewater. The changes and optimal values of influencing parameters, including treatment time, iron concentration, phenol initial concentration, and pH, were investigated based on the central composite design (CCD) method. The presence of 0.4 mmol/L of iron in the phenol solution with a concentration of 100 mg/L increased the removal efficiency and pseudo-first-order kinetic constant compared to dielectric barrier discharge cold plasma (DBDP) alone from 0.0824 min−1 and 56.8% to 0.2078 min−1 and 86.83%, respectively. The phenol removal efficiency was reduced to 52.9%, 45.6% and 31.8% by adding tert-butyl alcohol (TBA) with concentrations of 50, 100, and 200 mg/l, respectively. After 12 min of DBDP irradiation, the pH of the sample decreased from 5.95 to 3.42, and the temperature of the sample increased from 19.3 to 37.2 degrees Celsius. The chemical oxygen demand (COD) of the sample containing 100 mg/L phenol under plasma-Fenton/photo-Fenton irradiation decreased from 241 mg/L to 161 mg/L. Phenol removal efficiency after 10 min of treatment in the presence of 0.4 mmol/L of iron with the reactor volume of 50 mL was 87%, but the efficiency decreased to 76%, 47%, and 9% by increasing the volume to 100, 200, and 400 mL, respectively. Reducing the power led to a decrease in the removal efficiency from 56.8% for 100 W power to 10.8% for 40 W. The energy efficiency for 50% removal by DBDP and plasma-Fenton/photo-Fenton systems was 5.86×10−3 kWh/mg and 1.27×10−3 kWh/mg, respectively.

Preparation and characterization of optimized Ce and CTAB co-doped Blue-TiO2/PbO2 stable anode for phenol degradation

Electrochemical advanced oxidation processes (EAOPs) has attracted wide attention to researchers on all walks of life for the treatment of stubborn pollutants because of the strong oxidizing properties. However, the electrode materials currently developed have problems such as short life and low catalytic activity. In this work, the modification of PbO2 electrode was started by introducing into blue nanotubes (Blue-TiO2-NTs) based on the titanium plate to enhance the conductivity of the electrode. Then the β-PbO2 active layer was optimized by using cerium (Ce) and dodecyl trimethyl ammonium bromide (CTAB) through the method of electrodeposition to improve the electrocatalytic oxidation and stability. In the experiment of electrochemical oxidation, the degradation efficiency of phenol (100 mg/L) reached more than 96% after 120 min on the Blue-TiO2/PbO2-Ce-CTAB electrode. To further investigate the optimization mechanism of the Blue-TiO2/PbO2-Ce-CTAB anode in the electrocatalytic oxidation process, the surface structure, morphology, volt-ampere charge, oxygen evolution potential, and charge transfer resistance were evaluated. The result showed that the addition of CTAB reduced the crystal particles of PbO2, higher specific surface area of the electrode longitudinally by the Ce element, lower oxygen evolution potential, and smaller the resistance of charge transfer. Finally, the service life of the electrode was 6792 h by the accelerated life test on the current density of 25 mA cm−2. The energy consumption after 240 min of degradation was 0.079 kWh gCOD−1.This research proves that the Blue-TiO2/PbO2-Ce-CTAB electrode has potential application value in the degradation of phenol wastewater.

Immobilized horseradish peroxidase on boric acid modified polyoxometalate molecularly imprinted polymer for biocatalytic degradation of phenol in wastewater: Optimized immobilization, degradation and toxicity assessment

The degradation of phenol from wastewater is crucial for environmental protection. Biological enzymes, such as horseradish peroxidase (HRP), have shown great potential in the degradation of phenol. In this research, we prepared a hollow CuO/Cu2O octahedron adsorbent with a carambola matrix shape through the hydrothermal method. The surface of the adsorbent was modified by silane emulsion self-assembly, where 3-aminophenyl boric acid (APBA) and polyoxometalate (PW9) were combined with silanization reagents and grafted onto the surface. The adsorbent was then molecularly imprinted with dopamine to obtain boric acid modified polyoxometalate molecularly imprinted polymer (Cu@B@PW9@MIPs). This adsorbent was used to immobilize HRP, which served as a biological enzyme catalyst from horseradish. The adsorbent was characterized, and its synthetic conditions, experimental conditions, selectivity, reproducibility, and reusability were evaluated. The maximum adsorption amount of HRP under optimized conditions was 159.1 mg g−1, as determined using high-performance liquid chromatography (HPLC). At pH 7.0, the immobilized enzyme showed a high efficiency of up to 90.0% in removing phenol, after 20 min of reaction with 25 mmol L−1 H2O2 and 0.20 mg mL−1 Cu@B@PW9@HRP. Growth tests of aquatic plants confirmed that the adsorbent reduced harm. Gas chromatography-mass spectrometry (GC-MS) tests revealed that the degraded phenol solution contained about fifteen phenol derivatives intermediates. This adsorbent has the potential to become a promising biological enzyme catalyst for dephenolization.

Enhancement of Ozonation Reaction for Efficient Removal of Phenol from Wastewater Using a Packed Bubble Column Reactor

In the ozonation process, the phenol degradation in wastewater undergoes a low mass transfer mechanism. In this study, ozonized packed bubble column reactor was designed and constructed to remove phenol. The reactor’s inner diameter and height were 150 and 8 cm, respectively. The packing height was kept constant at 1 m in accordance with the reactor hydrodynamics. The gas distributor was designed with 55 holes of 0.5 mm. The phenol removal efficiency was evaluated at ozone concentrations of 10, 15, and 20 mg/L, contact times of 15, 30, 45, 60, 75, 90, 105, and 120 min, and phenol concentrations of 3, 6, 9, 12, and 15 mg/L. The results indicated that the highest phenol removal efficiency of 100% was achieved at 30 min in presence of packing. Moreover, the use of packing improved the contact between the gas and liquid, which significantly enhanced the phenol degradation. Actually, a thin film over a packing surface enhances the mass transfer. Also, it was found that the phenol is degraded into CO2 and H2O through a series of reaction steps. Additionally, a kinetic study of a first-order reaction provided an efficient estimation of reaction parameters with a correlation factor of 0.997.

Mesoporous LaVO4/MCM-48 nanocomposite with visible-light-driven photocatalytic degradation of phenol in wastewater

Dearomatization through photocatalytic oxidation is a swiftly rising phenolic compounds removal technology that works at trifling operations requirements with a special emphasis on the generation of nontoxic products. The study aims to develop a LaVO4/MCM-48 nanocomposite that was prepared via a hydrothermally approach assisting the employment of an MCM-48 matrix, which was then utilized for phenol degradation processes. Various techniques including UV–Vis DRS, FTIR, PL, Raman, TEM, and BET analyses are employed to characterize the developed photocatalyst. The developed photocatalyst presented remarkable characteristics, especially increased light photon utilization, and reduced recombination rate leading to enhanced visible-light-driven photodegradation performance owing to the improved specific surface area, specific porosities, and <2 eV narrow energy bandgap. The LaVO4/MCM-48 nanocomposite was experienced on aqueous phenol solution having 20 mg/L concentration under visible-light exposure, demonstrating exceptional performance in photodegradation up to 99.28%, comparatively higher than pure LaVO4. The conducted kinetic measurements revealed good accordance with pseudo first-order. A possible reaction mechanism for photocatalytic degradation was also predicted. The as-synthesized LaVO4/MCM-48 nanocomposite presented excellent stability and recyclability.

Assembly of Mg‐Mo‐Al‐Layered double hydroxides (LDHs) @ MoO42− and Its Synergistic Photocatalytic Degradation of Phenol in Wastewater

AbstractMg2+‐Mo6+‐Al3+‐MoO42−‐Layered double hydroxides (LDHs) materials were successfully prepared via a hydrothermal method by doping Mo6+ in hydroxide laminates and inserting MoO42− to replace the interlayer anions of LDHs materials. The samples were characterized by X‐ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM), Fourier transform infrared spectrometer (FTIRS) and ultraviolet‐visible spectrophotometer (UV). The electronic density of states was calculated using the density functional theory (DFT) of Vienna Ab‐initio Simulation Package (VASP). The effects of Mo6+ and MoO42− on the structure, morphology, electronic structure and photocatalytic performance of Mg2+‐Al3+‐LDHs were systematically studied. The conditions for phenol degradation by Mg2+‐Mo6+‐Al3+‐MoO42−‐LDHs were optimized by single factor analysis and response surface methodology. The results show that the MoO42− anion reduces the band gap width and thus enhances the absorption of low‐energy photons. The interaction between cations and anions enhances the photocatalytic performance. When the dosage of Mg2+‐Mo6+‐Al3+‐MoO42−‐LDHs was 0.03 g, the temperature was 40 °C and the visible light irradiation was 15 min, the removal rate of phenol reached 94.76 %.

Deactivation characteristics of Ce-modified Cu-based carbon materials for catalytic wet air oxidation of phenol wastewater

In this paper, Ce-modified Cu-based carbon materials (Cu-Ce/AC) were prepared by impregnation method using walnut shell as the carbon precursor, Cu-ammonia solution as Cu source and Ce as modifier. The catalytic wet air oxidation (CWAO) degradation of phenol wastewater was carried out in a self-assembled fixed-bed reactor. The stability of Cu-Ce/AC catalyst under different pH conditions was studied. This study combines XRD, BET, FT-IR, ICP-OES and XPS characterization techniques to study the main reasons for the deactivation of Cu-Ce/AC catalysts. The reaction mechanism of Cu-Ce/AC catalytic wet air oxidation degradation of phenol was clarified. The result indicates that although phenol was completely converted in the CWAO process, the acidic intermediate product produced were difficult to completely degraded. Therefore, the pH of the solution gradually decreased. In acidic environment, the interaction between active component Cu and carbon carrier is weak, resulting in a large amount of metal leaching into the solution. As a result, the COD conversion gradually decreases. The alkaline environment can effectively slow down the leaching of catalyst Cu while maintaining its high catalytic activity. In addition, the incompletely degraded intermediate products are easy to accumulate and deposit on the Cu-Ce/AC surface, block the micropores and cover the surface-active sites, which reduces the catalyst activity. The study also found that there is a redox cycle between Cu+, Cu2+ Ce3+ and Ce4+ during phenol degradation, which enables Cu and Ce to form a strong interaction. The redox cycle can also promote the formation of oxygen vacancy (h+), O2−·, and HO·, making the degradation of phenol more thorough. At the same time, the mutual conversion between metal lattice oxygen and surface chemisorbed oxygen can generate high concentration of oxygen defect sites, which can improve the oxygen storage capacity of Cu-Ce/AC. These oxygen vacancies also provide more reactive sites to further promote adsorption and catalytic oxidation degradation of phenol and intermediate products.

Magnetic carbon microspheres as a reusable catalyst in heterogeneous Fenton system for the efficient degradation of phenol in wastewater

Starch-based magnetic carbon microspheres (MCMs) were successfully synthesized by the hydrothermal method to degrade the simulating phenol-containing wastewater. The morphology and structure of the as-prepared MCMs were characterized by SEM, FT-IR, XRD, and VSM in detail. The characterization results showed that the presence of magnetic Fe3O4 in MCMs was conducive to the efficient removal of phenol in the Fenton system. When pH = 3, V(H2O2) = 0.30 mL, m(MCMs) = 3.0 g, T = 40 ℃, and t = 12 h, the degradation rate of phenol reached a maximum of 93.11%. After six repeated use, the degradation rate of phenol by MCMs still attained 85.14%, showing excellent reusability, which was extremely attractive to removing actual phenol-containing wastewater. The growth test of water spinach further confirmed that MCMs could effectively reduce the harmfulness of phenol to aquatic plants, indicating it was expected to become a promising material for the practical dephenolization application. Finally, the degradation mechanism of phenol in wastewater was proposed based on the experimental.

Photocatalytic Degradation of Phenol in Wastewater: A Mini Review

A major public health concern in many developing countries, including Nigeria, is the quality of their water supply. Everything a live entity does depends on water, a fundamental component of the biosphere. To ensure that water is safe for industrial and home use, it must be treated before consumption. However, phenolic compounds are found in our water bodies due to the polluted wastewater from industrial, agricultural, and home activities. Nature also has a role in their occurrence. These substances are poisonous and can cause long-term harm to both humans and animals. This paper reviewed research on the photodegradation of phenol utilizing nanoparticles in water treatment. This provides additional information and facts on cost-effective methods of treating wastewater and mineralizing phenol into valuable chemicals.

Degradation of phenol in batik industry wastewater using thin layer TiO2 photocatalyst

The synthesis of thin layer TiO2 photocatalyst has been performed and its performance was tested to the degradation of phenol in wastewater of batik industry. The powder of anatase TiO2 was impregnated in glass plate, so that thin layer TiO2 photocatalyst was obtained. The performance test of thin-layer TiO2 photocatalyst in the degradation of phenol was performed in a batch photoreactor equipped with six types of black light UV lamp (@10 watts) and a magnetic stirrer. This research has been performed at pH variation and UV radiation time. The result of this research showed that the initial concentration of phenol in batik wastewater was 3,3684 ppm. The optimum pH was obtained at pH 11 with percent degradation of 40.41%. The optimum UV radiation was obtained at 8 hours with percent degradation of 41.72%. The longer the irradiation time the more photon energy is absorbed by TiO2 causes more positive holes to be formed. The positive holes will react with H2O or hydroxyl ions to form OH radicals that further break down organic compounds in waste.

DNA directed immobilization of horseradish peroxidase on phase- transitioned lysozyme modified TiO2 for efficient degradation of phenol in wastewater

In this work, TiO2 nano particle was used for two purposes: it played as a role of a solid carrier for immobilization of HRP, and meanwhile acted as a photo-catalyst itself. In this way, the loss of enzymatic activity during enzyme immobilization can be compensated by the coupling of TiO2 photo-catalysis. Then, the surface of TiO2 nanoparticles were modified by phase-transitioned lysozyme (PTL) and connected with horseradish peroxidase (HRP) via a DNA helix (HRP-DNA-PTL@TiO2). The DNA double helix chain was utilized as a flexible spacer arm to keep the flexibility of the immobilized enzyme. The HRP-DNA-PTL@TiO2 showed a high recovered activity (90.52%) of the original activity of free HRP. This data is better than most reported activity recovery of immobilized enzyme. Moreover, HRP-DNA-PTL@TiO2 can maintain high catalytic activity, stability and reusability when degrading phenol in wastewater. The phenol of 0.5 mmol∙L−1 could be totally degraded within 10 min. Moreover, a visual colorimetric method for phenol concentration by HRP-DNA-PTL@TiO2 was established, and the phenol concentration of 0–0.2 mmol∙L−1 can be visually detected with naked eyes. Furthermore, an enzymatic-photocatalytic synergetic effect of HRP-DNA-PTL@TiO2 is found and investigated. The efficiency of HRP-DNA-PTL@TiO2 ensures it a potential application in the wastewater treatment.

Modelling of TiO2-based packing bed photocatalytic reactor with Raschig rings for phenol degradation by coupled CFD and DEM

As an alternative to the photocatalyst research, it is a promising approach by optimizing the macrostructure and reaction conditions to improve the photocatalytic performance of the TiO2-based packing bed photocatalytic reactor with Raschig rings. In this work, a packing bed photoreactor model with Raschig rings for the phenol degradation in wastewater is proposed based on the coupled computational fluid dynamics (CFD) and discrete element method (DEM), and verified by the experimental data. The multi-physical fields are presented and the photocatalytic performances are analyzed. The results show that the close cells perpendicular to the axis of the container, derived from the rings, lead to the weakened photocatalytic performance. However, the lower particle Reynolds number is favorable to the photocatalytic performance. The total decomposed phenol increases by 100.8% as the incident irradiation increases from 25 to 100 W/m2, and by only 11.4% from 100 to 200 W/m2. Besides, the photocatalytic reaction rate increases with reducing the diameter ratio of the rings to container and increasing the thickness of rings. As the aspect ratio of rings increases from 0.25 to 1.25, the outlet phenol concentration decreases by 10% after 30 min of reaction. This work could fill the knowledge gap between the unstructured geometry generation technologies and the real-geometry-based CFD modelling of packing bed photoreactors.

Heterojunction architecture of pTTh nanoflowers with CuOx nanoparticles hybridized for efficient photoelectrocatalytic degradation of organic pollutants

Herein, resulting from the heterojunction engineering, poly-terthiophene (pTTh) hybridized CuOxnanoparticles (abbreviated as CuOx@pTTh) are firstly synthesized and adopted as a promising photoelectrocatalyst for phenol degradation in wastewater. The resultant CuOx@pTTh manifests outstanding light-harvesting ability and remarkable capacity to separate photo-generated electron-hole pairs for phenol degradation in aqueous solution. X-ray photoelectron (XPS) characterizations and theoretical calculations further identify that there exists a strong electronic interaction between CuOx nanoparticles and pTTh, further enhancing the charge carriers transfer dynamics of the as-prepared catalysts. Electron spin resonance (ESR) spectroscopy and high performance liquid chromatography (HPLC) are applied to explore the active species and the degradation mechanism of photoelectrocatalyis (PEC) reactions. It is found that in PEC degradation of phenol the main active species are ·O2− and ·OH. Also, it can be concluded that phenol can eventually be step by step oxidized to CO2 and H2O through different pathways, according to the different detected intermediates.

Investigation of Enhancement of Spinning Disk Reactor on the Degradation of Phenol Wastewater by Photocatalytic System

Investigation of Enhancement of Spinning Disk Reactor on the Degradation of Phenol Wastewater by Photocatalytic System

Secondary battery inspired NiO nanosheets with rich Ni(III) defects for enhancing persulfates activation in phenolic waste water degradation

Sulfate radicals (SO4−) with broad pH tolerance and strong oxidation capacity are promising for Fenton-like reaction degradation of phenolic waste water. Ni-based catalysts and its compounds have been seldom reported as catalysts for the sulfate radical activation from persulfates (PDS) due to its inappropriate redox potential windows. A secondary battery inspired NiO nanosheets with rich Ni(III) defects were developed for Fenton-like catalysis via the charge/discharge process of NiOx/NiOx(OH)y redox cycle. The redox potential of Ni(II)/Ni(III) in NiOx/NiOx(OH)y cycle is high enough to activate S2O82− for the generation of SO4−. The Fenton-like performance of the defect-rich NiO nanosheets is most robust among the well-known sulfate radical activation catalysts of Co3O4, α-Fe2O3, MnOOH, and CuO. The enhancement effect of NiO was attributed to the formed Ni(III) defects, which could facilitate the discharge process of Ni(III) to Ni(II) and then enhance the Ni(III)/Ni(II) cycle during the Fenton-like process. The stability and recovery of defect-rich NiO nanosheets was also studied. Its high stability in chemical structure contributed to the low Ni leaching during the reaction process in basic or neutral condition. The recovery of defect-rich NiO nanosheets could be easily realized via the annealing treatment. In all, the secondary battery inspired defect-rich NiO nanosheets with outstanding sulfate radical activation would be a promising Fenton-like catalyst for environmental remediation.

Investigation of electrocatalytic activity of nanostructure Ce-doped MnO x sol–gel coating deposited on porous Ti membrane electrode

Ce-doped MnOx/Ti electrocatalytic membrane electrodes were prepared by doping rare earth element Ce into manganese oxide (MnOx) via sol–gel method, and coated on the porous Ti substrate membrane electrode. In order to evaluate electrocatalytic activity of the Ce–MnOx/Ti electrode, a functional electrocatalytic membrane reactor (ECMR), which assembled a Ce–MnOx/Ti electrode as an anode and a stainless steel mesh as a cathode, has been employed for phenolic wastewater treatment. The results revealed that a new crystal form Ce2O3 appeared after doping Ce into the system, and the urchinlike morphology and smaller grain size of Ce–MnOx led the catalytic activity of the composite membrane electrode to improve. Moreover, the 25 mol% Ce–MnOx/Ti (C25MT) composite membrane electrode represented the best activity in the degradation of phenolic wastewater. During ECMR with C25MT operation under the conditions of 450 mg/L phenolic wastewater (500 mL), residence time of 5 min, pH of 1–13 and current density of 0.3–1.2 mA/cm2, the highest degradation efficiency of phenolic wastewater achieved in current density of 0.9 mA/cm2 and pH of 7, that is, the achieved remove rate of phenol, COD and TOC were 99.61, 93.12, and 84.23%, respectively. Finally, the effective reusability of C25MT composite membrane electrode was assessed, and a proposed reaction mechanism has been analyzed in the ECMR operation.

Hydrothermal synthesis of series Cu-doped Bi2WO6 and its application in photo-degradative removal of phenol in wastewater with enhanced efficiency

To develop highly efficient photocatalyst for treatment of phenol-contained wastewater, Cu-doped Bi2WO6 (Cu-Bi2WO6) photocatalyst is synthesized via an optimized hydrothermal method. The influences of the synthesis parameters such as Cu loading, initial pH, reaction time and temperature on the crystal structure of Cu-Bi2WO6 are systematically examined from XRD, XPS, DRS and SEM analyses. The results show Cu doping leads to a significant red-shift of the absorption band of Cu-Bi2WO6 in visible light region. When Cu loading is 0.5wt%, Cu-Bi2WO6 shows sharp diffractions due to higher crystallinity, and further for pH=0.6, the prepared Cu-Bi2WO6 shows a narrow diffraction with greater intensity. Further analyses show that Cu-Bi2WO6 is characterized by a 3D flower spherical morphology expressing a relatively large micro-porosity size, with specific surface area as high as 85m2/g. The photocatalytic activity of Cu-Bi2WO6 for degradation of phenol in wastewater under visible light irradiation is systematically examined. The related kinetic study shows that Cu doping can greatly improve the photocatalytic activity of the resulting Cu-Bi2WO6, and moreover Cu loading has a great impact on the photocatalytic activity. Optimally, Cu-Bi2WO6 doped with 0.5wt% Cu exhibits the highest photocatalytic activity with the efficiency for phenol removal as high as 92%, 23% higher than that of pristine Bi2WO6 under the same condition. Our work provides a facile, cost-effective and environmentally friendly way to enhance the efficiency of Bi2WO6 for photo-catalytically degradative removal of phenol pollutants in wastewater.

A simple method to prepare high specific surface area reed straw activated carbon cathodes for in situ generation of H2O2 and ·OH for phenol degradation in wastewater

In electrochemical advanced oxidation processes (EAOPs), hydrogen peroxide (H2O2) can be converted to hydroxyl radicals (·OH) by oxidation–reduction reactions to degrade organic matter. To increase the generation of H2O2 and ·OH radicals, reed straw activated carbon (RSAC) was prepared by carbonization and activation methods and RSAC cathode was prepared by a tableting machine. The samples were observed by XRD, Raman, SEM, TEM and XPS. The electrochemical performance of the RSAC cathode was studied by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results show that the obtained RSAC has a large specific surface area, and its surface is rich in oxygen-containing functional groups and active sites, enabling a good degradation performance. The degradation rate of phenol in over 120 min was 93.06%. The chemical oxygen demand COD value decreased from 323.70 to 95.48 mg O2 L−1 in 360 min. The results indicate that RSAC has a good electrocatalytic activity.

Degradation of phenol in wastewater by cathodic microarc plasma electrolysis

ABSTRACTIn this paper, the cathodic microarc plasma electrolysis (CMPE) was tentatively performed to degrade the phenol in aqueous solution by vapor-gaseous envelope discharge around the Ti cathode. Degradation efficiency of phenol was measured and the intermediate products were evaluated. The suspended particles in solution were analyzed and the decomposition mechanism of phenol in the process of cathodic microarc plasma degradation was discussed. The instantaneous current efficiency reached a peak value firstly and then decreased with the discharge time. In the cathodic plasma region, the Cl substituted the hydrogen on benzene ring in the initial time, which was replaced by a hydroxyl immediately, then the polyhydroxy phenol was easily decomposed. In addition, optical emission spectroscopy was carried out to characterize the plasma features during the CMPE process. The temperature of electron around the microarc discharge envelope reached about 4000 K; thus the phenol was partly carbonized to become graphite particles. CMPE is a promising approach to degrade quickly the phenol in wastewater.