EF Process Research Articles

Vanadium doped Fe-Mn bimetallic oxides as cathodic materials for boosted heterogeneous electro-Fenton degradation of organic contaminants

The design of cathode materials with both sustainable H2O2 selectivity and accelerated recyclable regeneration remains a challenge for contaminants removal in heterogeneous electro-Fenton (HEF) process. Herein, a series of ternary Fe0.50Mn0.5−δVδOx (δ = 0.005, 0.01, 0.05) metal oxides have been synthesized and employed as cathodic materials for the degradation of various organic contaminants in water matrix. 99.7 % removal rate was achieved for carbamazepine (CBZ) in 60 min with 98.8 % mineralization rate. Simultaneously, the catalyst exhibited outstanding degradation efficiency (96.0–99.7 %) with other pollutants including sulfonamides (SMX), bisphenol A (BPA), 2,4-dichlorophenol (2,4-DPC) and ofloxacin (OFX), demonstrating its potential application. Factors affecting the EF process, including current density, pH, oxygen flow rate and compatibility of inorganic anions were thoroughly evaluated and the degradation mechanism was studied in detail. Density functional theory (DFT) calculations revealed that the improved catalytic efficiency was originated from vanadium doping to access optimized electronic structure, which endows enhanced 2e− ORR selectivity as well as excellent overall performance for the EF process. This work may enrich the study on EF system and offers a promising strategy for contaminants removal with FeMnVO materials in water treatment applications.

Degradation of antiviral drug molnupiravir using a dual function FeIIFeIIILDH@carbon felt cathode in the heterogeneous electro-Fenton process: Kinetics and mineralization study

Pharmaceuticals constitute one of the more widely reported anthropogenic micropollutants, and their removal usually requires a specific treatment method. The oxidative degradation and mineralization of molnupiravir (MNP), a novel antiviral drug used for COVID treatment, were investigated for the first time by EF processes using both raw carbon felt (CF) and modified dual-function CF cathodes. The classical electro-Fenton (CEF) process using CF cathode has significant challenges, including a narrow pH range and a lack of ability to reuse the catalyst. To overcome these limitations, a dual-function FeIIFeIII layered double hydroxide modified carbon felt (FeIIFeIIILDH@CF) cathode was developed using a hydrothermal method. The FeIIFeIIILDH@CF cathode was characterized using BET, FTIR, SEM, cyclic, and linear sweep voltammetry. The efficiency of FeIIFeIIILDH@CF cathode for the removal of MNP compared with that of raw carbon felt (CF) cathode, including the effects of operating parameters. The heterogeneous electro-Fenton (HEF) process with FeIIFeIIILDH@CF cathode allowed an almost complete mineralization (98.08 % TOC removal) of 0.1 mM MNP solution. The mineralization ability of the FeIIFeIIILDH@CF cathode was more than 95 % after 5 cycles, suggesting a good reusability of the synthesized cathode. The absolute rate constant for the oxidation of MNP with ●OH (2.22 ± 0.03 ×109 M−1 s−1) was also determined for the first time. In addition, the modified LDH cathode has the advantage of being effective over a wide pH range while avoiding the use of an iron salt as a catalyst.

Electrochemical selection of ferrous phosphide (FexP) as efficient catalyst for wastewater treatment: Performance and mechanism

Iron phosphide (FexP) has a great potential for electrochemical catalysis attributing to its outstanding electrical conductivity and activity. In the present study, a series of FexP (FeP, Fe2P and Fe3P) were carried out as catalysts for the oxidation of phenol from wastewater by the heterogeneous EF processes. Compared with FeP and Fe2P catalysts, Fe3P has shown significant two-electron oxygen reduction activity and H2O2 selectivity (90–100 %). The degradation efficiencies of phenol in Fe3P/EF (100 %) were higher than those in Fe2P/EF (91 %) and FeP/EF (67 %) upon 60-min electrochemical oxidation under pH 7. The Fe3P-CF/EF system could broaden the range of solution pH, as well the decay kinetics of phenol was enhanced by 1.5–2.4 times and the disposal cost was reduced by 33–41 % compared with FeP/EF and Fe2P/EF. Feɑ+ in Fe3P could promote the generation of •OH via accelerating Fe(II)/Fe(III) cycle and accelerating the transfer rate of electrons between Fe3P and H2O2. It was proved that •OH played a dominant role in removing phenol with the electron spin resonance (ESR) tests and trapping experiments. This work selected the most effective FexP catalyst in heterogeneous EF process and would bring new insights for organics removal from wastewater via H2O2 activation.

Accelerated Cr (VI) removal by a three-dimensional electro-Fenton system using green iron nanoparticles.

Green-synthesized iron nanoparticles (GAP-FeNP) were used as particle electrodes in a three-dimensional electro-Fenton (3DEF) process to accelerate the removal of hexavalent chromium [Cr (VI)]. Removal was evaluated by varying the pH (3.0, 6.0, and 9.0) and initial Cr (VI) concentrations (10, 30, and 50 mg/L) at 5 and 25 min. These results demonstrated that GAP-FeNP/3DEF treatment achieved more than 94% Cr (VI) removal under all tested conditions. Furthermore, it was observed that Cr (VI) removal exceeded 98% under pH9.0 in all experimental parameters tested. The results of the response surface methodology (RSM) determined two optimal conditions: the first, characterized by a pH of 3.0, Cr (VI) concentration at 50 mg/L, and 25min, yielded a Cr (VI) removal of 99.7%. The second optimal condition emerged at pH9.0, with Cr (VI) concentrations of 10mg/L and 5min, achieving a Cr (VI) removal of 99.5%. This study highlights the potential of the GAP-FeNP to synergistically accelerate Cr (VI) removal by the 3DEF process, allowing faster elimination and expansion of the alkaline (pH9.0) applicability. PRACTITIONER POINTS: The required time for >99% of Cr (VI) removal by the GAP-FeNP/3DEF process was shortened from 25 to 5min. EF process with GAP-FeNP reduces the time necessary for Cr (VI) removal, which is 67% faster than conventional methods. EF process using GAP-FeNP removed >94% of Cr (VI) after 25 min for all initial Cr (VI) concentrations and pH treatments. Cr (VI) removal by the GAP-FeNP/3DEF process was >98% at a pH of 9.0, widening the solution pH applicability.

Engineered diatomic catalyst empowered electro-Fenton processes for advanced water purification

This work introduces the selection and preparation of DACs for the 2 + 1e− ORR EF process and concludes with a discussion on challenges and future directions for the intelligent design of electrodes and reactors in EF purification technologies.

Facile synthesis of bimetallic ACF/CC@FeOCl–Cu composite cathode for efficient degradation of sulfamethoxazole at neutral pH by a flow-through heterogeneous electro-Fenton process

Flow-through heterogeneous electro-Fenton (FHEF) process shows a broad prospect for refractory organic pollutants removal. However, maintaining a long-term service life of higher catalytic cathode is crucial for the development of cathode materials, especially for iron-functionalized cathode operated under harsh conditions. In this study, a novel bimetallic CC@FeOCl–Cu composite was synthesized through one-step calcination, coupled with a series of microstructure characterization methodology, including XRD, SEM-EDS, XPS, and FTIR. The superior catalytic activity of CC@FeOCl–Cu could be ascribed to Fe–Cu synergy and better dispersion of FeOCl nanosheets. With the optimal Cu:Fe ratio of 1:60, the bifunctional ACF/CC@FeOCl–Cu cathode was employed in FHEF process, exhibiting an outstanding performance for sulfamethoxazole (SMX) removal over a wide pH range (3.0–9.0). Comparison of experimental results indicated that the ACF/CC@FeOCl–Cu-FHEF process showed higher performance than ACF/CC@FeOCl-FHEF and homogeneous EF processes. The average SMX removal efficiency was 98% and TOC removal efficiency was more than 57% even after 10 cycles. Radical quenching experiments and electron spin resonance test confirmed that •OH was the primary active species. More •OH was generated in the ACF/CC@FeOCl–Cu-FHEF process because the doping of Cu could enhance catalytic activity of cathode. In addition, the satisfactory performance could be observed in the ACF/CC@FeOCl–Cu-FHEF process for the treatment of real landfill leachate, indicating its potential for practical application in wastewater treatment.

Study of tramadol removal from water by the electro-Fenton process coupled with biological post-treatment: kinetics and energetic evaluation

ABSTRACT The pollution of the aquatic environment by the increasing presence of the non-biodegradable analgesic tramadol (TRA) is increasing due to its high consumption and incomplete elimination in conventional wastewater treatment processes. The aim of the present study is, firstly, to evaluate the oxidative degradation of TRA by the ‘electro-Fenton’ process, EF for short, at pH 3 (optimal operating pH) for 6 h at a constant current between 60 and 400 mA. Secondly, the possibility of coupling biological treatment with EF will be investigated in order to minimise energy input and increase the profitability of the treatment process. The experimental results showed a considerable mineralisation rate of TRA of over 94% after 6 h of electrolysis at an applied current of 300 mA and a Fe2+ catalyst concentration of 0.1 mM. The TRA degradation in this process followed pseudo-first order kinetics. Several TRA intermediates were identified by LC-MS/MS analysis. A likely reaction pathway for the process of mineralisation was suggested. Combining the EF process with biological post-treatment reduces the energy consumption by more than 66% and increases the economic viability of TRA mineralisation.

Performance and working mechanism of a coal fly ash-based particle electrode in the catalytic oxidation of ofloxacin in a three-dimensional electro-Fenton reactor

Coal fly ash (CFA), corn straw, and pharmaceutical wastewater are typical solid and liquid wastes. In this study, activated carbon (CSAC) was first produced by carbonising corn straw, and then a particle electrode with Fenton-like catalytic performance (Fe/CFA-CSAC) was prepared and used in a three-dimensional electro-Fenton process (Fe/CFA-CSAC EF process) to treat ofloxacin-simulated wastewater (OSW). Fe/CFA-CSAC was first characterised using SEM+EDX, XRF, BET test, and XRD, and then the critical treatment parameters of OSW were optimised (T = 30 °C, aeration rate = 3 L/min, current density = 12 mA/cm2). The catalytic oxidation process was critical in the degradation of ofloxacin, while the adsorption process played an auxiliary role. The water quality had a significant improvement, 63.6 % of COD and 51.4 % of TOC were eliminated, BOD5/COD was increased from 0.12 to 0.44, and the toxic inhibition rate was reduced by 40.8 %. Fe/CFA-CSAC EF process can effectively work in a wide pH range (2.0–9.0) and can be used at least 25 cycles. The material costs required for the preparation of Fe/CFA-CSAC was $219.9/ton and the treatment cost of OSW was $1.71/ton. Finally, the working mechanism of Fe/CFA-CSAC was proposed.

Degradation of carbamazepine over MOFs derived FeMn@C bimetallic heterogeneous electro-Fenton catalyst

A highly efficient heterogeneous electro-Fenton (Hetero-EF) catalyst with core-shell structure was successfully prepared by calcination of Mn-doped Mil-53 (Fe) precursor at high temperature. FeMn@C-800/2 prepared at pyrolysis temperature of 800 °C and Fe:Mn molar doping ratio of 2:1 showed the best catalytic performance for the degradation of carbamazepine (CBZ). The characterization, properties and stability of FeMn@C-800/2 were systematically investigated, obtaining the apparent first-order reaction rate of Hetero-EF was 8.9 and 17.8 times higher than that on Fe@C-800 and Mn@C-800 at the optimized conditions of current density 10 mA cm−2, catalyst dosage of 50 mg L−1 and initial pH 4.0, respectively. The incorporation of Mn promoted the generation of more Fe0 and Fe3C during the pyrolysis process, and enhanced the internal micro-electrolysis between Fe0 and carbon shell. At the same time, the presence of Mn0 also promoted the regeneration of Fe2+, and improved the activity of iron-carbon heterogeneous catalysis in the EF process, so as to degrade organic pollutants more effectively. This work would help to gain insight into the design of MOFs derived Fe–Mn bimetal catalyst and its mechanism for enhanced heterogeneous electro-Fenton.

The Electro-Fenton Process for Caffeine Removal from Water and Granular Activated Carbon Regeneration

The electro-Fenton process (EF) has faced major challenges, including mass transfer limitations. When the targeted pollutants are present in water at very low concentrations, the degradation kinetics are slower than desired, which leads to high energy consumption. To overcome this drawback, coupled adsorption on activated carbon (AC) and the EF process can be performed. Therefore, the compounds can be preconcentrated on AC before elimination by the EF process. As such, in this study, batch experiments were conducted using low-cost granular activated carbon (GAC) packed in a stainless-steel mesh for the adsorption of caffeine. Once saturated, GAC is used as a cathode during the EF process, where the adsorption capacity is regenerated. This approach allows the regeneration of the AC for multiple cycles and the degradation of the desorbed compounds. The EF process was studied to this end, for the purposes of the removal of caffeine as a model compound. The main goals of this work are (i) to study the removal of caffeine from water in three different matrices and (ii) to regenerate GAC by using the EF process. The results reported in this study show that it is possible to achieve caffeine degradation up to 95%, 100%, and 100%, and a mineralization up to 70%, 72%, and 76% in pure water, simulated wastewater, and wastewater effluent, respectively. In the regeneration process, total elimination of the desorbed caffeine was achieved, and a regeneration efficiency of 50% was obtained for the first cycle. The results confirm the ability of the EF process to achieve regeneration of AC loaded with caffeine.

Research on two-step advanced treatment of old landfill leachate by sequential electrochemical peroxidation-electro-Fenton process

Electrochemical technology is an alternative method for the removal of high concentration ammonium-N (NH4+-N) and refractory organics from old landfill leachate (OLL). However, the limited performance of a single electrochemical process and the subsequent long tertiary treatment time to meet the water quality standards are the key technical problems that hinder its practical application. This study demonstrates that the sequential ECP-EF process can realize two-step advanced treatment of OLL. Under the optimal conditions (ECP: j = 30 mA cm−2, initial pH = 9.0; EF: j = 30 mA cm−2, initial pH = 3.5), the removals of COD, TOC, NH4+-N, and TN can be achieved 95.9 ± 0.4 %, 85.1 ± 0.8 %, 99.4 ± 0.1 %, and 99.2 ± 0.1 %, respectively, to meet the first-class standard of integrated wastewater discharge standard of China. The organics in OLL are mainly removed by ECP process and further mineralized or converted to small molecular hydrophobic components in EF process. The sequential ECP-EF process can reduce the aromaticity and complexity of organics, as well as can decrease the acute cytotoxicity (ACT) and hydrophilicity. A proper electrolysis time can effectively avoid the rise of ACT, energy consumption, and cost. The treatment cost ($0.0134 L−1) is approximately 32 % less than the previously reported electrochemical processes of electrocoagulation/electro-Fenton. These findings obtained with real OLL provide a basis for scaling up this new sequential electrochemical treatment approach.

FeMo@porous carbon derived from MIL-53(Fe)@MoO3 as excellent heterogeneous electro-Fenton catalyst: Co-catalysis of Mo

An ultra-efficient electro-Fenton catalyst with porous carbon coated Fe-Mo metal (FeMo@PC), was prepared by calcining MIL-53(Fe)@MoO3. This FeMo@PC-2 exhibited impressive catalytic performance for sulfamethazine (SMT) degradation with a high turnover frequency value (7.89 L/(g·min)), much better than most of reported catalysts. The mineralization current efficiency and electric energy consumption were 83.2% and 0.03 kWh/gTOC, respectively, at low current (5 mA) and small dosage of catalyst (25.0 mg/L). The removal rate of heterogeneous electro-Fenton (Hetero-EF) process catalyzed by FeMo@PC-2 was 4.58 times that of Fe@PC/Hetero-EF process. Because the internal-micro-electrolysis occurred between PC and Fe0, while the co-catalysis of Mo accelerated the rate-limiting step of the Fe3+/Fe2+ cycle and greatly improved the H2O2 utilization efficiency. The results of radical scavenger experiments and electron paramagnetic resonance confirmed the main role of surface-bound hydroxyl radical oxidation. This process was feasible to remove diverse organic contaminants such as phenol, 2,4-dichlorophenoxyacetic acid, carbamazepine and SMT. This paper enlightened the importance of the doped Mo, which could greatly improve the activity of the iron-carbon heterogeneous catalyst derived from metal-organic frameworks in EF process for efficient removal of organic contaminants.

Electrodeposition of FeOOH nanosheets on carbon felt for enhanced sulfamerazine removal via visible light-assisted electro-Fenton process

How to accelerate the Fe(III)/Fe(II) cycle to improve •OH generation is of significance for heterogeneous electro-Fenton (hetero-EF) cathode. In this work, FeOOH nanosheets modified carbon felt (FeOOH/CF) were prepared by in-situ electrodeposition and used as a hetero-EF cathode for enhanced sulfamerazine (SMR) removal via visible light-assisted electro-Fenton (vis-EF) process. Material characterization results suggested that the interaction between FeOOH and CF was strengthened via the formation of Fe-O-C bonding due to the special electrodeposition method. As expected, the as-prepared cathode exhibited excellent EF catalysis ability and visible light activation. With visible light assistance, the SMR removal rate for FeOOH/CF-40 was as high as 92.41%, which was increased by 110% compared with the pristine EF process. In addition, the applicable pH range could be expanded to a mild condition for FeOOH/CF cathode via the vis-EF process. Only 0.13% of total electrodeposited Fe was leached to the solution, indicative of good stability. Mechanism analysis revealed that the enhanced electron transfer via Fe-O-C bonding can significantly promote Fe(III)/Fe(II) cycle under visible light irradiation, thus activating the in-situ generated H2O2 to produce abundant •OH. These findings proved FeOOH/CF would be a promising hetero-EF cathode for practical water treatment with solar energy assistance.

Electro-Fenton treatment process for brewery wastewater: effects of oxidant concentration and reaction time on BOD and COD removal efficiency

The brewing process consumes and releases a large amount of wastewater into the environment. The objective of this study was to determine optimum operating conditions for the treatment of brewery wastewater using the Electro-Fenton (EF) process. The EF process has been applied to a wide variety of pollutants due to its ability to remove complex and recalcitrant water contaminants. Brewery wastewater contains large amounts of biodegradable and non-biodegradable compounds which are suitable for the EF process. The effect of hydrogen peroxide (H2O2) concentration and reaction time (RT) on the biological oxygen demand and chemical oxygen demand of the EF process was investigated. The brewery wastewater with an initial BOD and COD of 423.76 mg/l and 854.86 mg/l respectively was subjected to changing H2O2 concentrations of 250, 500, 1000, 2000, 3000, and 4000 mg/l and reaction times of 30, 45, 60, 90, and 120 min. Other conditions such as ferric-sulfate catalyst concentration, voltage, electrode spacing, and pH were maintained constant. The BOD and COD showed considerable changes after applying the EF process. Removal efficiencies for BOD and COD were significant (p < 0.05), up to 96.91% (423.76–13.04 mg/l) and up to 93.16% (854.86–58.5 mg/l), respectively. Results further showed increasing concentrations of hydrogen peroxide and reaction time favored BOD and COD removal. The efficiency was analyzed using analysis of variance (ANOVA) and graphical plot. The optimum BOD and COD removal of 88.96% (46.79 mg/l) and 93.16% (58.51 mg/l) was observed at 2000 mg/l hydrogen peroxide and 120 min reaction time. Optimized experimental conditions and performance have been discussed in the literature. The analysis of the treated wastewater shows that there is a significant reduction of BOD and COD compared with the raw wastewater. Therefore, it is suggested that the EF process be applied in the treatment of brewery wastewater for removing BOD, COD, and some other complex pollutants. The treated water can be reused or safely disposed into the environment.

Improving Adherence to Behavioral Parent Training for ADHD Using Digital Health Tools.

Behavioral Parent Training (BPT) is a well-established treatment for school-age children with ADHD but lack of parent adherence to prescribed parenting strategies limits treatment gains. Digital Health (dHealth) tools can be leveraged to target barriers to parent adherence but existing tools for parenting interventions are limited. New efforts to develop a dHealth tool to target adherence barriers including limited skill competence, EF processes, and low motivation/negative attitudes, are presented and recommendations for future technology-enhanced treatments are provided.

Graphite felt modified by nanoporous carbon as a novel cathode material for the EF process

Nanoporous carbon prepared by carbonizing ZIF-8@MWCNTs can greatly improve the performance of graphite felt as an electro-Fenton cathode.

A novel electro-Fenton process coupled with sulfite: Enhanced Fe3+ reduction and TOC removal

To promote the reduction of Fe3+ and improve the mineralization of organic pollutants, a novel electro-Fenton coupled with sulfite (Fe3+-EF/sulfite) process was constructed, which was superior to Fe3+-EF process in terms of carbamazepine (CBZ) degradation and mineralization with 5.99 times enhancement in degradation rate constant and 15.7 times enhancement on TOC removal. The complexation of Fe3+ and sulfite prevented the precipitation of Fe3+, reduced Fe3+ to Fe2+, and accelerated the iron cycle, so that H2O2 utilization efficiency (0.051 mgTOC mgH2O2−1) was greatly improved and electric energy consumption was greatly reduced (0.081 kWh g−1 TOC). The quenching experiments and EPR test confirmed that the reactive species, such as SO3•-, SO4•-, •OH, O2•- and 1O2 were responsible for the degradation of CBZ. This process also expanded the pH application range from 3 to 9 with satisfactory CBZ removal efficiency. This work verified the suitability of the Fe3+-EF/sulfite process for different sulfites (sulfite and bisulfite), typical pollutants (atrazine, sulfamethazine, rhodamine B) and real wastewater with 2.1–18.7 folds enhancement in degradation rate. The Fe3+-EF/sulfite process can achieve deep mineralization with low cost and simple operation, which has a broad and cost-effective application prospect in removal of refractory organic pollutants.

Hybrid electro-Fenton and peroxi-coagulation process for high removal of 2,4-dichlorophenoxiacetic acid with low iron sludge generation

2,4-D is one of the most predominant herbicides around the world, though many advanced oxidation processes (AOPs) including peroxi-coagulation (PC) have been applied for its removal, the traditional PC still has restricted application due to disadvantages of huge sludge generation for a high pollutant removal and increased subsequent disposal costs. Herein, we developed a hybrid EF and PC process, using iron and dimensionally stable anode (DSA) electrodes as anodes, and a natural air diffusion electrode (NADE) without external aeration as the cathode. The optimal conditions for the hybrid process were optimized (initial pH 3, initial 2,4-D concentration 100 mgL−1, and total current of 100 mA with the ratio of DSA anode and iron anode of 7:3). Under these optimal conditions, 2,4-D could be almost completely removed within 30 min, and the TOC removal reached 71.9% within 2 h with a low electric energy consumption (EEC) of 19.59 kWh kg−1 TOC. The performance was comparable with traditional PC process but the iron sludge generation significantly reduced by ~73%. Therefore this hybrid process would have more potential to replace traditional PC process with cost-effective pollutants removal, low iron sludge generation and low EEC.

A transdiagnostic examination of anxiety and stress on executive function outcomes in disorders with social impairment

BackgroundExecutive function (EF) difficulties characterise a number of psychiatric conditions and EF impairment may be a predisposing factor and/or consequence of anxiety and stress. The aim of the study was to examine EF factors in a mixed clinical cohort (Autism Spectrum Disorder and Social Anxiety Disorder) characterised by social impairment and investigate the influence of trait anxiety and state-based depression, anxiety and stress. MethodsIn Study 1, a factor analysis identified EF and non-EF latent factor structures (N=205). In Study 2, (N=137) multiple regression analyses investigated the association between trait anxiety and state based depression, anxiety and stress, on EF and non-EF cognitive domains and on the two composite indices of the Behavioural Rating Inventory of Executive Function (BRIEF). ResultsTrait anxiety was associated with better performance on neuropsychological measures of EF while state-based stress was associated with lower EF performance. A dissociation was observed between trait anxiety and state stress on the two behavioural indices of the BRIEF. Depression, anxiety and stress did not predict performance on non-EF cognitive domains. LimitationsThe cross-sectional design precludes cause-effect conclusions, further only self-report measures of affect were utilised and our performance measures of EF did not include a working memory test. ConclusionsThe results demonstrate that trait anxiety and state-based stress influence EF processes across disorders with social impairment. The transdiagnostic efficacy of this finding can facilitate remediation strategies, it may also contribute to individuals with Autism Spectrum Disorder gaining better access to mental health services.

An Integrated Approach to Remove PAHs from Highly Contaminated Soil: Electro-Fenton Process and Bioslurry Treatment

A combined process comprised of electro-Fenton and bioslurry (EF–bioslurry) was developed at lab scale for remediating a real coking plant soil with an initial polycyclic aromatic hydrocarbons (PAHs) content of 3605 mg/kg. Sodium citrate was used as a complexant to keep the iron in solution at near-neutral pH conditions for increasing the reaction rate. The appropriate order of application was to perform EF process followed by bioslurry, which was evaluated through analysis of degradation characteristics of individual processes. The optimum EF duration was assessed through an analysis of the induced changes in PAHs degradation and bacterial counts. The optimum application time of EF process was determined to be 24 h. The removal of PAHs was 95.2% for EF–bioslurry after 40 days, and the efficiency was increased by almost 150%, compared with the individual bioslurry treatment. The EF reaction caused significant cell death and high inhibition to polyphenol oxidase (PPO) activity of soil. The bacterial activity and counts in the slurry recovered rapidly after EF oxidation through the addition of raw soil (2%, w/w). Therefore, the combined process of EF–bioslurry process may be an efficient and promising approach for the remediation of highly organic-contaminated soil.