Electrochemical Membrane Filtration Research Articles

A novel electrochemical membrane filtration system operated with periodical polarity reversal for efficient resource recovery from nickel nitrate laden industrial wastewater

The economical and efficient removal of nickel nitrate from industrial wastewater remains a challenge. Herein, we developed an innovative electrochemical membrane filtration system that used a periodic polarity reversal process to adjust the acid-base environment near membrane interface for the recovery of nickel (II) and ammonia. The Ru based electrocatalytic layer could boost the selective reduction of nitrate to ammonia by generating atomic hydrogen, resulting in the precipitation of Ni2+ by the increasing pH at the membrane interface. Then, the precipitation of Ni(OH)2 could be effectively stripped and collected under the periodic polarity reversal process. In-situ interfacial measurements demonstrated that the polarity reversal process enabled a reversible transformation between strongly acidic (pH < 2) and alkaline (pH > 13) environments within a 200 µm range at the membrane interface. In continuous flow operation treating real industrial wastewater containing 96.7 mg-N L−1 nitrate and 135.0 mg L−1 Ni2+, the system demonstrated the capability to achieve 92.5 ± 2.6 % nitrate removal (with a recovery efficiency of 15.1 ± 1.9 g-NH3 kWh−1) and 99.7 ± 0.1 % Ni²⁺ removal (with a recovery efficiency of 24.9 ± 2.4 g-Ni kWh−1). Additionally, the specific treatment cost was approximately $0.17 m−3, attributed to the recovery of Ni(OH)₂ and ammonia. Furthermore, this system could deliver a significant economic benefit ($1.64 per m3) for treating a high concentration real wastewater (331.5 mg-N L−1 nitrate and 1496.3 mg L−1 Ni2+), outperforming traditional alkali precipitation and biological nitrification/denitrification processes. Overall, our study presents an economical and sustainable method for recovering valuable chemicals from wastewater containing heavy metals and inorganic nitrogen, potentially advancing cost-effective water treatment technologies.

Spray-coated PDA-wrapped carboxylic CNT/PES membrane to augment fouling mitigation, organic removal, and membrane stability in electrochemical membrane filtration

This study introduces robust and conductive polydopamine (PDA)-wrapped carboxylic carbon nanotube (C-CNT)-coated polyethersulfone (PES) membrane for electrochemical membrane filtration to treat greywater. Self-polymerized dopamine was prepared directly under oxidative conditions on the CNT strands, followed by their immobilizations on the surface of the PES membrane through a novel spray-coating technique. The spraying coating technique improved both the durability of the coating layer and membrane permeability by 27 % higher than that prepared by the conventional vacuum filtration method. The spraying coating technique enhanced the electroactive properties of the PDA/C-CNT membrane so that the fouling rate was reduced more effectively than the C-CNT membrane or bare PES membrane. Fouling mitigation of the PDA/C-CNT membrane was attributed to the combined effect of electrostatic repulsions between the foulants and the conductive membrane surface along with degradation of organic compounds by electrochemical oxidation. The constant current density profile also confirmed the structural stability of the conductive layer on the membrane under both cathodic and anodic conditions. Furthermore, the fouling layer formed by membrane filtration was removed effectively by in-situ anodic cleaning. Over 80% of water permeability was recovered without losing the membrane integrity up to 3 consecutive anodic cleaning cycles.

Tuning electrostatic repulsive and acid–base forces for efficient fouling mitigation in membrane filtration system

Membrane fouling caused by colloidal particles and microorganisms impose restrictions to further practical implementation of membrane separation technology. To advance the practical applications of this technology sustainably, this study explores an in-situ fouling control strategy utilizing an electrochemical membrane filtration (EMF) system. By applying varying electric potentials, the study evaluated the impact on dissolved organic matter (DOM) removal and elucidated the fouling mechanisms involved. The results indicate that increasing the potential significantly enhances the water flux of the conductive carbon membrane (CC/PVDF), with the flux at 3.0 V being 2.1 times greater than at 0 V. Moreover, this adjustment in potential significantly reduces the attachment of viable bacteria to the CC/PVDF membrane, with an applied potential greater than or equal to 2 V completely inactivating Escherichia coli (E. coli). The cohesive free energy (ΔGSWS) and extended Derjaguin–Landau–Verwey–Overbeek (XDLVO) theories suggest that imposing an external potential improved the acid–base and electrostatic repulsive forces between foulants and the membrane, as the applied potentials significantly increased the surface potential and wettability of the membrane. This EMF system not only mitigates fouling effectively but also delineates a path for enhancing membrane durability in practical applications.

Easily scale 3D conductive gradient fiber membrane for contaminants removal and fouling mitigation under electrochemical assistance

An electrochemical membrane filtration system provides an innovative approach to enhance contaminant removal and mitigate membrane fouling. There is an urgent need to develop portable, versatile, and efficient electrochemical membranes for affordable wastewater treatment. Here, a 3D conductive gradient fiber membrane (CC/PVDF) with a gradient porous structure was prepared using a two-step phase inversion method. Methyl orange (MO) was utilized as model organic substance to investigate the electrochemical performance of the CC/PVDF membrane. At applied potentials of +2 V, +3 V, −2 V and −3 V, the removal efficiency of MO was 5.1, 5.3, 4.8, and 5.1 times higher than at 0 V. A dramatic flux loss of 35.02% occurred on the membrane without electrochemistry, interestingly, whereas the flux losses were only 23.59%–10.24% in the applied potential after 30 min of filtration, which were approximately 1.18, 1.28, 1.29 and 1.38 times as high as that without electrochemistry, respectively. The enhanced removal and anti-fouling performances of the membranes were attributed to the functions of electrochemical degradation, electrostatic repulsion, and electrically enhanced wettability. Electrochemical generation of Hydrogen peroxide, along with HO• radicals, was detected and direct electron transfer and HO• were proved to be the dominant oxidants responsible for MO degradation. The intermediate oxidation products were identified by mass spectrometry, and an electrochemical degradation pathway of MO was proposed based on bond-breaking oxidation, ring-opening reactions, and complete oxidation. All the findings emphasize that the ECMF system possesses superior efficiency and creative potential for water purification applications.

Electrochemical oxidation of reverse osmosis concentrate using a pilot-scale reactive electrochemical membrane filtration system: Performance and mechanisms

Scale-up treatment of real wastewater holds the key to promoting the practical application of electrochemical filtration technology. This work used a pilot-scale Ti/Pd reactive electrochemical membrane (REM) system (12 REM modules with a total REM area of 0.144 m2) to treat high-salinity reverse osmosis concentrate (ROC) from a chemical industry park. The pilot-scale Ti/Pd REM system demonstrated effective electrochemical degradation of ROC wastewater, achieving removal efficiencies of 82.3 ± 1.9% for COD and 46.7 ± 5.6% for TN at a membrane flux of 90 L/(m2·h) and a cell voltage of 5 V, with an energy consumption of 0.045 kWh/g-COD. Singlet oxygen (1O2) and reactive chlorine species were identified as the two primary reactive oxygen species generated in the Ti/Pd REM system. Fluorescence spectroscopy and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) analysis indicated that the pilot-scale Ti/Pd REM treatment effectively oxidized humic acid-like substance and unsaturated aromatic compounds. Overall, the Ti/Pd REM technology shows a promising application potential for the treatment of high-salinity ROC from the chemical industry.

Antibiotic Removal, Toxicity Reduction, and Antibiotic Resistance Development Inhibition Using Janus Electrochemical Membrane Filtration

Antibiotic Removal, Toxicity Reduction, and Antibiotic Resistance Development Inhibition Using Janus Electrochemical Membrane Filtration

Electrochemical abatement of aquatic metoprolol by porous foam-titanium based metal oxide anodic membranes

Electrochemical membrane filtration (EMF) is a promising advanced oxidation technology for eliminating aquatic refractory pharmaceuticals. In this work, three porous foam-titanium based metal oxide (MOx) anodic membranes were prepared for comparison of their effectiveness against the model pharmaceutical pollutant metoprolol. The electrooxidation efficiencies of metoprolol by all flow-by operated anodic membranes were found to be elevated with increasing charging voltage and decreasing electrolyte solution pH, in which the PbO2 membrane exhibited more efficient metoprolol degradation efficiency over SnO2 and RuO2 membranes. At the chosen charging voltage of 2 V and electrolyte solution pH 7, compared to the flow-by mode, the higher total organic carbon (TOC) removal and less electrical energy consumption was achieved by the flow-through operated PbO2 membrane, ascribed to the enhanced mass-transfer of metoprolol and its intermediate by-products toward the anode surface. The physisorbed and free HO• produced by PbO2 membrane were found to be the key oxidants accounting for metoprolol degradation, which induced the transformation of metoprolol by attacking its benzene ring and side chains. Apart from the capacity for detoxifying metoprolol-containing influent, PbO2 membrane also exhibited favorable stability in flow-through mode. The study provides an effective strategy for the electrochemical remediation of pharmaceutical-polluted water and wastewater.

Efficient removal of bromate from contaminated water using electrochemical membrane filtration with metal heteroatom interface

Efficient utilization of atomic hydrogen (H*) is of great importance for achieving efficient bromate reduction using electrochemical technologies. Herein, an electrochemical membrane with metal heteroatom interface of Ru and Ni was developed to enhance the utilization efficiency of H* via the membrane filtration process. The RuNi membrane demonstrated 91.3% of bromate removal at 5 mA cm−2 under the flow-through operation (40 L m−2 h−1). Cyclic voltammetry (CV) curves and electron spin resonance (ESR) spectra elucidated that the bromate reduction was mainly attributed to H* -mediated reduction rather than the direct electron transfer between bromate and RuNi active layer. The quenching experiments revealed a significant contribution of adsorbed H* to the bromate removal during the membrane filtration. Based on X-ray photoelectron spectrometry and X-ray diffraction analyses, we found that the resultant Ru0Ni0 structure on the electrochemical membrane could facilitate the generation of H* during the bromate reduction reaction. Besides, the higher pH might suppress the formation of H* and increase the energy barrier for breaking the Br-O bond, resulting in dramatic increase of energy consumption for removing bromate. Our work highlights the potential of utilizing H* in electrochemical membrane for removing bromate in water treatment and remediation.

Identifying the Active Sites of Heteroatom Graphene as a Conductive Membrane for the Electrochemical Filtration of Organic Contaminants

The dopants of sulfur, nitrogen, or both, serving as the active sites, into the graphitic framework of graphene is an efficient strategy to improve the electrochemical performance of electrochemical membrane filtration. However, the covalent bonds between the doped atoms and the substrate that form different functional groups have a significant role in the specific activity for pollutant degradation. Herein, we found that the singly doped heteroatom graphene (NG and SG) achieved superior removal efficiency of pollutants as compared with that of the double doped heteroatom graphene (SNG). Mechanism studies showed that the doped N of NG presented as graphitic N and substantially increased electron transfer, whereas the doped S of SG posed as -C-SOx-C- provided more adsorption sites to improve electrochemical performance. However, in the case of SNG, the co-doped S and N cannot form the efficient graphitic N and -C-SOx-C- for electrochemical degradation, resulting in a low degradation efficiency. Through the fundamental insights into the bonding of the doped heteroatom on graphene, this work furnishes further directives for the design of desirable heteroatom graphene for membrane filtration.

Electrochemical removal and recovery of phosphorus from wastewater using cathodic membrane filtration reactor

Removal and recovery of phosphorus (P) from wastewater is of great importance to addressing the challenges of eutrophication and phosphorus shortage. The P removal and recovery performance of conventional electrochemical precipitation approach was constrained by the limited mass transfer rate. Herein, a cathodic membrane filtration (CMF) reactor was developed using Ti/SnO2-Sb anode and titanium mesh cathodic membrane module to achieve efficient removal and recovery of P in wastewater. Compared with the flow-by mode, the CMF system in the flow-through mode exhibited excellent P removal performance due to the markedly enhanced mass transfer. At the current density of 4 A/m2, membrane flux of 16.6 L m−2 h−1, and Ca/P molar ratio of 1.67, the removal efficiency of P was 96.2% and the energy consumption was only 45.7 kWh/kg P. The local high pH of cathode surface played a vital role in P removal, which substantially accelerated the nucleation of calcium phosphate (CaP). Based on the crystalline and morphological characterization of the precipitates, the hydroxyapatite was the most stable crystalline phase of CaP, which was transformed from intermediate phases (such as dicalcium phosphate and amorphous calcium phosphate). This study paves the way for applying electrochemical membrane filtration system for P removal and recovery from wastewater.

A novel electrocoagulation-membrane stripping hybrid system for simultaneous ammonia recovery and contaminant removal

This study developed an innovative and cost-effective electrochemical membrane filtration system, which utilized electrocoagulation (EC) with electrically conductive membranes (ECMs) as cathode and membrane stripping (MS) for simultaneous ammonia recovery and contaminant removal. The novel system takes advantages of the two complementary processes (EC and MS) when sequentially performed. Electrocoagulation produced positively charged coagulants which removed contaminants. ECMs served as cathode of EC in-situ generated OH–, which converted NH4+ ions to volatile NH3. MS recovered NH3 and prevented from membrane fouling or wetting due to the protection of ECMs. The mechanism involves electrocoagulation, electrolysis and electrostatic interaction. Operating conditions (e.g., current density, electrolyte concentration and pollutants concentration) have significant impacts on process performance. Increasing the current density from 0 to 40 A/m2 exerted a positive effect on humic acid (HA) removal, ECM fouling mitigation and ammonia recovery. However, excessive current density (60 A/m2) shortened the contact time between NH4+ and OH–, and thus decreased ammonia recovery. High electrolyte concentration enhanced ammonia recovery, which can be attributed to increased pH and longer contact time between NH4+ and OH–. On the contrary, low electrolyte concentration was beneficial for ECM fouling mitigation through enhancing electrostatic repulsion between membrane electrode and HA contaminants. The improvement of HA concentration not only aggravated ECM fouling, but also had adverse effect on ammonia recovery. NH4Cl concentration had negligible effect on HA removal and membrane fouling, but the generation of OH– became a rate-limiting factor for ammonia recovery at high NH4Cl concentration. Our results demonstrated that the novel system exhibited a competitive performance with other alternatives, with HA removal efficiency of 99.2% and ammonia recovery efficiency of 68.6% at a current density of 40 A/m2, electrolyte concentration of 100 mmol/L, HA concentration of 30 mg/L and NH4Cl concentration of 300 mg/L, which can be considered as an appealing technology for ammonia resource recovery.

Efficient removal of micropollutants from low-conductance surface water using an electrochemical Janus ceramic membrane filtration system

Electrochemical membrane filtration (EMF) technology is effective to remove the micropollutant in the wastewater but its efficacy is drastically compromised in treating the surface water having a typically low conductivity. In this work, a Janus Fe-Pt electrochemical ceramic membrane (ECM) was fabricated by depositing a thin Fe layer on the side of a ceramic membrane facing feed (cathode) and Pt layer on the other side facing permeate (anode). The low Fe-Pt electrode distance (∼1 mm) ensured a decent conductance of the EMF system even in the low-salinity surface water and thereby maintained the removal efficiency of the micropollutant. It was identified that hydroxyl radicals (•OH) generated via anodic water oxidation and cathodic heterogenous Fenton process on bilateral sides of ECM were the dominant reactive oxygen species. The EMF system not only achieved 74% removal of atrazine (ATZ) from the low-conductance synthetic surface water with a low energy consumption (3.6 Wh per gATZ or 7.2 Wh m − 3), but also realized a stable removal of ATZ from real surface water over a continuous filtration experiment of 168 h. The theoretical computations and experimental analysis identified the degradation pathway, i.e., the dechlorination and dealkylation of ATZ in the EMF system. This study highlights the great potential of the Janus ECM in removing micropollutants from low-conductance surface water and wastewater.

Self-Enhanced Decomplexation of Cu-Organic Complexes and Cu Recovery from Wastewaters Using an Electrochemical Membrane Filtration System

Heavy metals in industrial wastewaters are typically present as stable metal-organic complexes with their cost-effective treatment remaining a significant challenge. Herein, a self-enhanced decomplexation scenario is developed using an electrochemical membrane filtration (EMF) system for efficient decomplexation and Cu recovery. Using Cu-EDTA as a model pollutant, the EMF system achieved 81.5% decomplexation of the Cu-EDTA complex and 72.4% recovery of Cu at a cell voltage of 3 V. The •OH produced at the anode first attacked Cu-EDTA to produce intermediate Cu-organic complexes that reacted catalytically with the H2O2 generated from the reduction of dissolved oxygen at the cathode to initiate chainlike self-enhanced decomplexation in the EMF system. The decomplexed Cu products were further reduced or precipitated at the cathodic membrane surface thereby achieving efficient Cu recovery. By scavenging H2O2 (excluding self-enhanced decomplexation), the rate of decomplexation decreased from 8.8 × 10-1 to 4.1 × 10-1 h-1, confirming the important role of self-enhanced decomplexation in this system. The energy efficiency of this system is 93.5 g kWh-1 for Cu-EDTA decomplexation and 15.0 g kWh-1 for Cu recovery, which is much higher than that reported in the previous literature (i.e., 7.5 g kWh-1 for decomplexation and 1.2 g kWh-1 for recovery). Our results highlight the potential of using EMF for the cost-effective treatment of industrial wastewaters containing heavy metals.

Realizing the Intrinsic Electrochemical Activity of Acidic N‐Doped Graphene through 1‐Pyrenesulfonic Acid Bridges

AbstractElectrochemical technology attracts much research interest for the treatment of metal complexes, but most electrocatalysts are incapable of effectively degrading metal complexes, which generally have highly stable cages with five or six rings coordinating with metal ions. To address this, a bridging agent linking the catalysts and metal complexes can lower the energy barrier, and thus holds much promise to facilitate the removal of such pollutants. In this study, 1‐pyrenesulfonic acid (PSA) functionalization of acidic nitrogen‐doped graphene (ANG) is successfully synthesized and found to effectively remove metal complexes through electrochemical membrane filtration. Results indicate that PSA, interacting with Cu‐EDTA via the strong ion exchange of super acidic sulfonic (−SO3H) groups, acts as a conductive “bridge” connecting the electrocatalyst and metal complexes to overcome the challenge with penetrating the “cage” structure of metal complexes. The pyrrolic nitrogen of ANG is found to be the active sites in the electrochemical process, with the intrinsic electrochemical activity realized by the bridging agent, namely, PSA. This study highlights the importance of compounds with sulfonyl groups in circumventing the stable “cage” of the metal complexes, and thereby paves the way for effective degradation of such pollutants.

Microalgae Filtration Using an Electrochemically Reactive Ceramic Membrane: Filtration Performances, Fouling Kinetics, and Foulant Layer Characteristics.

Electrochemical membrane filtration has proven to be successful for microbial removal and separation from water. In addition, membrane fouling could be mitigated by electrochemical reactions and electrostatic repulsion on a reactive membrane surface. This study assessed the filtration performances and fouling characteristics of electrochemically reactive ceramic membranes (a Magneli phase suboxide of TiO2) when filtering algal suspension under different dc currents to achieve anodic or cathodic polarization. The critical flux results indicate that when applying positive or negative dc currents (e.g., 1.25-2.5 mA·cm-2) to the membrane, both significantly mitigated membrane fouling and thus maintained higher critical fluxes (up to 14.6 × 10-5·m3·m-2·s-1 or 526 LMH) compared to the critical flux without dc currents. Moreover, applying dc currents also enhanced membrane defouling processes and recovered high permeate flux better than hydraulic and chemical backwash methods. Moreover, fouling kinetics and the cake layer formation were further analyzed with a resistance-in-series model that revealed many important but underexamined parameters (e.g., cake layer resistance and cake layer thickness). The cake layer structures (e.g., compressibility) were shown to vary with the electrochemical activity, which provide new insight into the biofouling mechanisms. Finally, the algogenic odor, geosmin, was shown to be effectively removed by this reactive membrane under positive dc currents (2.5 mA·cm-2), which highlights the multifunctional capabilities of electrochemically reactive membrane filtration in biomass separation, fouling prevention, and pollutant degradation.

Electrochemically enhanced simultaneous degradation of sulfamethoxazole, ciprofloxacin and amoxicillin from aqueous solution by multi-walled carbon nanotube filter

Electrochemical filters exhibited excellent properties of time saving and energy conservation and were widely used in water purification. In this work, an efficient method was proposed for degrading antibiotics including sulfamethoxazole (SMZ), ciprofloxacin (CIP) and amoxicillin (AMO) in both single system and mixed system by utilizing multi-walled carbon nanotube (MWCNT)-based electrochemical membrane. The effect of experimental parameters was investigated with respect to voltage, pH, temperature, initial pollutant concentration and sodium dodecyl benzene sulfonate (SDBS). The recycling experiments of MWCNT-based electrochemical filter were also performed. Results revealed that the degradation efficiency could be enhanced by increasing the voltage and temperature, while it decreased with the increased initial pollutant concentration and the addition of SDBS. Degradation of SMZ and AMO was weakly affected by solution pH. However, the degradation efficiency of CIP in acidic or alkaline solution was much higher than that in neutral solution. Furthermore, the MWCNT-based electrochemical membrane still exhibited high efficiency for antibiotic degradation after reuse of four times, which could facilitate the development of reproducible and low-cost pollutant-processing method. Noticeably, this membrane filter also presented high performance on simultaneously removing the multiple antibiotics with the efficiency order of AMO (98%) > SMZ (95%) > CIP (20%). The degradation mechanism of antibiotics by the MWCNT-based membrane was analyzed and a clear explanation on the antibiotics-removed pathway was provided. These results indicated that the MWCNT-based electrochemical membrane filtration may have potential to effectively treat multiple antibiotics in real wastewater.

Effective Removal of Sulfanilic Acid From Water Using a Low-Pressure Electrochemical RuO2-TiO2@Ti/PVDF Composite Membrane.

Removal of sulfanilic acid (SA) from water is an urgent but still challenging task. Herein, we developed a low pressure electrochemical membrane filtration (EMF) system for SA decontamination using RuO2-TiO2@Ti/PVDF composite membrane to serve as not only a filter but also an anode. Results showed that efficient removal of SA was achieved in this EMF system. At a charging voltage of 1.5 V and a electrolyte concentration of 15 mM, flow-through operation with a hydraulic retention time (HRT) of 2 h led to a high SA removal efficiency (80.4%), as expected from the improved contact reaction of this compound with ROS present at the anode surface. Cyclic voltammetry (CV) analysis indicated that the direct anodic oxidation played a minor role in SA degradation. Electron spin resonance (ESR) spectra demonstrated the production of •OH in the EMF system. Compared to the cathodic polarization, anodic generated ROS was more likely responsible for SA removal. Scavenging tests suggested that adsorbed •OH on the anode (>•OH) played a dominant role in SA degradation, while was an important intermediate oxidant which mediated the production of •OH. The calculated mineralization current efficiency (MCE) of the flow-through operated system 29.3% with this value much higher than that of the flow-by mode (5.1%). As a consequence, flow-through operation contributed to efficient oxidation of SA toward CO2 and nontoxic carboxylic acids accounting for 71.2% of initial C. These results demonstrate the potential of the EMF system to be used as an effective technology for water decontamination.

Degradation of sulfadiazine in drinking water by a cathodic electrochemical membrane filtration process

In this study, a novel electrochemical membrane filtration (EMF) process was proposed to degrade sulfadiazine (SDZ) in drinking water, and the oxidation mechanisms, kinetics, byproducts and primary impact factors were investigated. In the EMF process, a novel membrane was used as the cathode and two graphite plates were used as anodes. Five oxidation byproducts including 4-OH-sulfadiazine or 5-OH-sulfadiazine, 2-aminopyrimidine, 4-amino-N-carbamimidoyl benzene sulfonamide and 2,5-dihydroxypyrimidine were identified. Possible degradation pathways for SDZ were proposed, and OH and ▪ were recognized to be the major reactive oxygen species contributed for SDZ degradation. The degradation of SDZ by EMF followed pseudo-first-order kinetics in batch experiment and the rate constant increased as the applied voltages increased. Compared with the batch experiment, the flow-through mode of EMF slowed SDZ degradation, and the degradation rate also decreased as the flux increased. However, on the base of mass balance calculations more SDZ was degraded in flow-through mode as compared with that in batch experiment. Finally, the degradation of SDZ in natural waters from a municipal drinking water treatment plant was investigated with flow-through mode, and the result shows that the degradation rate (79%) was slightly lower than that obtained for deionized water due to the low conductivity of real-world water systems.

Contaminant Removal from Source Waters Using Cathodic Electrochemical Membrane Filtration: Mechanisms and Implications.

Removal of recalcitrant anthropogenic contaminants from water calls for the development of cost-effective treatment technologies. In this work, a novel electrochemical membrane filtration (EMF) process using a conducting microfiltration membrane as the cathode has been developed and the degradation of sulphanilic acid (SA) examined. The electrochemical degradation of SA in flow-by mode followed pseudo-first-order kinetics with the degradation rate enhanced with increase in charging voltage. Hydrogen peroxide as well as oxidants such as HO• and Fe(IV)O2+ were generated electrochemically with HO• found to be the dominant oxidant responsible for SA degradation. In addition to the anodic splitting of water, HO• was formed via a heterogeneous Fenton process with surface-bound Fe(II) resulting from aerobic corrosion of the steel mesh. In flow-through mode, the removal rate of SA was 13.0% greater than obtained in flow-by mode, presumably due to the better contact of the contaminant with the oxidants generated in the vicinity of the membrane surface. A variety of oxidized products including hydroquinone, p-benzoquinone, oxamic acid, maleic acid, fumaric acid, acetic acid, formic acid, and oxalic acid were identified and an electrochemical degradation pathway proposed. These findings highlight the potential of the cathodic EMF process as an effective technology for water purification.