Heterogeneous Fenton Process Research Articles

Modeling of heterogeneous Fenton process for dye degradation in a fluidized-bed reactor: Kinetics and mass transfer

Abstract Natural pyrite catalysts were utilized in fluidized bed reactor for dye degradation in presence of hydrogen peroxide, which is famous to heterogeneous Fenton reaction. This process plays an important role in wastewater treatment processes and it is more effective when occurs in this kind of reactors. A novel kinetic model for Acid yellow 36 (AY36) degradation by heterogeneous Fenton process, in a fluidized bed reactor has been developed. By evaluating dissolved oxygen (DO) concentration in effluent during the process, a new parameter named effective reaction time is introduced, which could describe the relation of DO concentration and dye degradation, so the prediction of DO concentration by the model is of great importance toward the understanding of process performance. Neglecting mass transfer phenomenon from kinetic models eventuated in incorrect estimation, consequently, in this model, both reaction and mass transfer mechanism have been considered, which forecast the changes in effective factors like pH, DO concentration and dye removal efficiency simultaneously. The model results adequately coincide with the experimental results, which declare the validity of the modified kinetic model.

On the critical use of zero valent iron nanoparticles and Fenton processes for the treatment of tannery wastewater

The use of iron nanoparticles in the heterogeneous Fenton oxidation treatment of tannery wastewater was investigated. A comparison with the conventional oxidation process, involving Fe(II) addition was performed. The main operating parameters influence, such as pH, temperature and reagents amount, on total phenolic species, total organic compounds, Cr(VI) content and chemical oxygen demand reduction was investigated.Heterogeneous Fenton oxidation resulted more efficient and fast with respect to the conventional process, but a higher amount of iron was required in the process. In this case, the optimal conditions were assessed at H2O2/COD (w/w) = 0.5, nZVI/H2O2 (w/w) = 0.75 and pH = 3, achieving a total Cr(VI) removal as well as a remarkable TOC, COD and phenols degradation efficiency (up to 70, 73 and 88%, respectively). The best results were obtained with the combination of the two processes, fixing the optimal conventional Fenton operating parameters (H2O2/COD (w/w) = 0.75, Fe(II)/H2O2 (w/w) = 0.15 and pH = 2.5), adopting a nZVI/H2O2 (w/w) ratio equal to 0.2. In such conditions, that also allowed to reduce the catalyst amount used with respect to the Heterogeneous Fenton process, a noticeable TOC, COD and phenols removal efficiency (81.15, 87.44 and 94.04%, respectively) was achieved. In addition, the iron sludge production of such combined process was close to that obtained in the conventional one.

Preparation of magnetite nanoparticles by high-energy planetary ball mill and its application for ciprofloxacin degradation through heterogeneous Fenton process

In this study, the heterogeneous Fenton oxidation of ciprofloxacin (CIP) in an aqueous solution was examined over the nano-sized magnetite (Fe3O4) as a catalyst supplied through high-energy planetary ball milling process. To characterize the magnetite samples after and before ball milling operation, the X-ray diffraction (XRD), High-resolution scanning electron microscopy (HR-SEM), energy-dispersive X-ray spectroscopy (EDX), Brunauer-Emmett-Teller (BET) and Fourier transform infrared spectroscopy (FTIR) analysis were applied. The catalytic properties of the magnetite were considerably improved because of the enhancement in its physical properties, resulted from milling process. The findings also indicated that 6 h ball-milled magnetite demonstrated better properties for elimination of CIP of about 89% following 120 min reaction at optimal conditions of H2O2 12 mM, Fe3O4 1.75 g L−1, CIP 10 mg L−1 and pH 3.0. The effects of various operational parameters, including the initial pH of the solution, H2O2 initial concentration, catalyst dosage, milling time and CIP initial concentration was investigated. Application of organic and inorganic scavengers considerably decreased the CIP removal efficiency. Correspondingly, with respect to the leached iron values at pH 3, it was concluded that CIP elimination was mainly occurred through heterogeneous Fenton procedure. This process included the adsorption and oxidation phases in which the hydroxyl radicals (OH) played a significant role. GC-MS analysis was used for recording of the generated intermediates of the CIP removal in the course of heterogeneous Fenton process.

Effects of Good's Buffers and pH on the Structural Transformation of Zero Valent Iron and the Oxidative Degradation of Contaminants.

The presence of Good's buffers caused rapid ZVI corrosion and a dramatic release of Fe(II) leading to the Fe(II)-catalyzed transformation of ferrihydrite to lepidocrocite and/or the direct formation of lepidocrocite from the oxidation of Fe(II) in the pH range 4.0-6.2. In comparison, in the absence of Good's buffers, elution of Fe(II) was insignificant with ferrihydrite being the only Fe(III) oxyhydroxide detected following the oxidative transformation of ZVI. The rapid ZVI corrosion in the presence of Good's buffer is possibly due to either (i) disruption of the Fe oxide surface layer as a result of attack by Good's buffers and/or (ii) interaction of Good's buffer with the outer Fe oxide surface and surface-associated Fe(II)/Fe(III) causing the Fe oxide surface layers to be more porous with both these processes facilitating continuous O2 access to the Fe(0) core and allowing the diffusion of Fe atoms outward. Our results further show that the deprotonated forms of Good's buffers and the surface charge of the Fe oxides formed at the ZVI surface strongly affect the sorption of the target compound (i.e., formate) and hence the oxidation of these compounds via surface-associated Fe(II)-mediated heterogeneous Fenton processes.

Accelerated degradation of orange G over a wide pH range in the presence of FeVO4

In this study, FeVO4 was prepared and used as Fenton-like catalyst to degrade orange G (OG) dye. The removal of OG in an aqueous solution containing 0.5 g·L–1 FeVO4 and 15 mmol·L–1 hydrogen peroxide at pH 7.0 reached 93.2%. Similar rates were achieved at pH 5.7 (k = 0.0471 min–1), pH 7.0 (k = 0.0438 min–1), and pH 7.7 (k = 0.0434 min–1). The FeVO4 catalyst successfully overcomes the problem faced in the heterogeneous Fenton process, i.e., the narrow working pH range. The data for the removal of OG in FeVO4 systems containing H2O2 conform to the Langmuir–Hinshelwood model (R2 = 0.9988), indicating that adsorption and surface reaction are the two basic mechanisms for OG removal in the FeVO4–H2O2 system. Furthermore, the irradiation of FeVO4 by visible light significantly increases the degradation rate of OG, which is attributed to the enhanced rates of the iron cycles and vanadium cycles.

New composite materials based on activated carbon fibers with specific adsorption and catalytic properties

The problem of creation of new materials based on activated carbon fibers for catalytic, sorption, and energy storage processes is discussed. Examples of the use of modified carbon fibers as adsorbents for purification from arsenic and phenols related to the toxic and priority contaminants are presented. It is shown that use of the carbon fiber modified with Mn and Mo let to purify solutions from arsenic on a level of its low concentrations. Decontamination of solution from 3-chlorophenol is carried out the most effectively in the heterogeneous Fenton-process using the carbon fiber modified with iron/iron oxide as catalyst.

Degradation of tri(2-chloroethyl)phosphate by a microwave enhanced heterogeneous Fenton process using iron oxide containing waste.

Iron oxide containing waste was first used in the microwave (MW) enhanced heterogeneous Fenton process for removing tri(2-chloroethyl)phosphate (TCEP) in aqueous solution. The operational parameters that affect the removal efficiency were investigated in detail. Comparing with the traditional Fenton-like reaction and heating assisted Fenton-like reaction, the MW enhanced heterogeneous Fenton process displayed superior treatment efficiency. The iron ore tailing can be reused eight times without significant decrease of catalytic efficiency. The major intermediates were identified and the possible degradation pathways of TCEP were proposed. The acute toxicity gradually decreased during the degradation process and the removal of TOC was 98.8% after 35 min reaction. This study could not only apply the waste tailing as a secondary resource to avoid the tedious preparation of the catalyst, but also proposes a rapid, low-cost and effective alternative method for the removal of polluted water containing TCEP.

Heterogeneous activation of peroxymonocarbonate by Co-Mn oxides for the efficient degradation of chlorophenols in the presence of a naturally occurring level of bicarbonate

An activated peroxymonocarbonate (PMC) system is expected to be developed as a chemical oxidation technology for water remediation, especially for the karstic regions with naturally occurring bicarbonates. In the present study, CoxMn3−xO4 (cobalt manganese oxides, where x = 1.08, 1.5, 1.77) catalysts with micron-sized spherical structures were prepared via a solvothermal method followed by an annealing process. Characterization results showed that all the prepared CoxMn3−xO4 catalysts were well-crystallized spinels with porous micro-nano hierarchical structures. Compared to Co3O4 and Mn2O3 catalysts with similar microstructures, the CoxMn3−xO4 catalysts had lower oxidation potentials and more redox-active sites, therefore demonstrating improved PMC activation for the degradation of 2,4-dichlorophenol (2,4-DCP). The activated PMC process (with 5 mM bicarbonate) showed a moderate H2O2 consumption rate, but it was more efficient for the degradation of 2,4-DCP than the heterogeneous Fenton (H-Fenton) process (H2O2 + CoxMn3−xO4 catalysts). In a mixture of H2O2, bicarbonate and CoxMn3−xO4 catalyst, the activated PMC process was the dominant route for the degradation of 2,4-DCP, in which the generated hydroxyl radicals (OH) mostly combined with bicarbonate ions, resulting in a more complex oxidizing mechanism involving various free radicals, e.g. O2−, OH and CO3−. Moreover, it was observed that bicarbonate dosage played a more significant role than H2O2 dosage in the degradation of 2,4-DCP, further validating that the activated PMC process was the major contributing route for decontamination of the organics. Based on the experimental results of the PMC system, the functioning mechanism of CoxMn3−xO4 catalysts and the oxidizing routes of 2,4-DCP were depicted. With the use of high-performance Co-Mn binary oxides, the activated PMC method can be engineered for groundwater remediation in karstic regions.

Heterogeneous nZVI-induced Fenton oxidation process to enhance biodegradability of excavation by-products

The treatment of excavation by-products has been studied using Fenton and Heterogeneous Fenton processes, by the addition of zero-valent iron nanoparticles (nZVI) as catalyzer. This study demonstrated that both methods could significantly reduce the organic content of the liquid extract from excavated soils. Operating parameters, such as pH and catalyzer/oxidant (w/w) ratio, were varied to investigate their influence on the Total Organic Carbon (TOC) and Chemical Oxygen Demand (COD) removal efficiency. In addition, Biochemical Oxygen Demand (BOD) was evaluated before and after the treatment. The optimal conditions found for conventional Fenton process were: H2O2/COD = 1 (w/w), Fe(II)/H2O2 = 0.1 (w/w) and pH = 2.5, whereas for Heterogeneous Fenton were: H2O2/COD = 0.75 (w/w), nZVI/H2O2 = 1.5 (w/w) and pH = 3. Heterogeneous Fenton resulted more efficient with respect to conventional Fenton, leading to a TOC and COD removal efficiency equal to 75.95 and 85.52%, respectively. The BOD28/COD ratio after Heterogeneous Fenton increased by about 200%, indicating the suitability of this oxidation process to achieve a biodegradability increase.

Iron Supported on Ion Exchange Resin as Source of Iron for Fenton Reagent: A Heterogeneous or a Homogeneous Fenton Reagent Generation?

Abstract The aim of this work is to discuss the relative contribution of homogeneous and heterogeneous Fenton processes in the treatment of Orange II dye solutions at pH 3 and 7 using an ion exchange resin as iron support. While at pH 3, 99% of the colour was removed, under neutral conditions a decoloration of 56% was observed. Studying the release of iron from the resin, we found a concentration of 1.49 mg/L of ferric ion and 0.31 mg/L of ferrous ion at pH 3 and 1.08 mg/L and 0.11 mg/L at pH 7, revealing that as expected, dissolution of iron ions at pH 3 is larger. Using these concentrations in a homogeneous process, 45% of the colour can be removed at pH 3 and 10% at pH 7, so it was infered that there is an effect of the iron that is still supported on the resin. In this way, a mixed homogeneous/heterogeneous mechanism could be proposed. While the experimental data for the desorption of iron at pH 3 was well suited to a pseudo second order kinetic model, the desorption of iron at pH 7 was fit to pseudo-first order kinetics. Experimental results of dye decolorization were on the other hand, fitted to a pseudo first order kinetics.

Fast decolorization of azo methyl orange via heterogeneous Fenton and Fenton-like reactions using alginate-Fe2+/Fe3+ films as catalysts

The efficiency of Fenton and Fenton-like processes can be seriously affected by the continuous loss of iron ions and by the formation of solid sludge. Here, alginate (Alg) films were synthesized to stabilize iron ions (Fe2+ and Fe3+) and to enhance their catalytic activities towards the decolorization of methyl orange via heterogeneous Fenton and Fenton-like processes. Iron ions were ionically bond to the Alg molecules resulting in a three-dimensional network with specific structural and morphological features according to the valence states of iron. Our results demonstrated that both Alg-Fe2+ and Alg-Fe3+ films show highlighted catalytic activity for the decolorization of MO and high decolorization rates. Reuse experiments demonstrated that both films could be employed in at least five consecutive decolorization processes without losing their catalytic efficiency or stability. Taken together, our findings reveal that the Alg-Fe2+ and Alg-Fe3+ films may be suitable low-cost catalysts in heterogeneous Fenton and Fenton-like processes.

Reactivity of novel Ceria–Perovskite composites CeO2- LaMO3 (MCu, Fe) in the catalytic wet peroxidative oxidation of the new emergent pollutant ‘Bisphenol F’: Characterization, kinetic and mechanism studies

In the present study, ceria, pristine perovskites LaMO3 (Cu, Fe) and novel ceria-perovskite composites CeO2-LaMO3 were successfully prepared and applied as heterogeneous Fenton like- catalysts for the degradation and mineralization of a new emergent compound- bisphenol F (BPF) in aqueous solution. The catalysts were characterized by X-ray diffraction spectrometer (XRD), BET surface area determination, scanning electron microscopy (SEM), Energy Dispersive X-ray (EDS) and X-ray photoelectron spectroscopy (XPS) techniques. Catalytic bisphenol F behavior shows that the activity of pristine perovskites was improved due to the introduction of cerium. Catalytic activity in terms of TOC removal followed the order of CeO2-LaCuO3>CeO2-LaFeO3>LaCuO3>LaFeO3>CeO2 with about 83, 79, 68, 64 and 28% respectively. Only the novel composite oxide CeO2-LaCuO3 was found to be effective for Bisphenol F degradation at neutral conditions. EPR analyses and scavenging experiments revealed that BPF was mainly decomposed by the attack of OH, especially the surface-bounded OH. BPF decay followed pseudo-first-order reaction kinetics. The absolute rate constant for BPF oxidation by OH was found to 2.09109M−1s−1, as determined by the competition kinetic method. Six stable organics intermediates were observed and five of them were identified p-benzoquinone, hydroquinone, 4-hydroxybenzaldehyde and Bis (4-hyroxyphenyl) methanol. Subsequent attack of these intermediates by OH radicals led to the formation of short chain acids: malonic, succinic, acetic, formic and oxalic acids. On the basis of the analytical results for the intermediate products and the assumption that hydroxyls radicals are the major reactive species, a plausible pathway of BPF mineralization during the heterogeneous Fenton process was proposed. Furthermore, the CeO2-LaCuO3 composite exhibited excellent long-term stability in the heterogeneous Fenton-like process. These results suggested that the novel ceria perovskite material would be a promising candidate for practical wastewater treatment.

Degradation of phenol by heterogeneous Fenton process in an impinging streams reactor with catalyst bed

AbstractIn the present study, the decomposition of phenol in aqueous solutions was investigated in both impinging system and batch reactor. In impinging reactor, catalyst particles with an average diameter of 1.5 × 103μm were confined in a wired cage located in the middle of the reaction vessel. The catalyst was synthesized by impregnation of iron on clinoptilolite zeolite as the support. The mean residence time of the solution in this reactor was 3 s. Therefore, the number of impingements required for the complete degradation of phenol was assessed to be 8 times. The advantage of performing the impinging reactor over a conventional reaction system has been demonstrated in this study. In the impinging reactor at 55 °C, time needed for degradation of phenol in aqueous media was measured to be as low as 24 s; however, phenol degraded completely in 10 min in batch stirred reactor. The optimum operating conditions for the impinging reactor were found as: catalyst containing 5 wt% iron, pH = 3.25, weight ratio of H2O2/phenol = 20, temperature = 55 °C. © 2017 Curtin University of Technology and John Wiley & Sons, Ltd.

Semi-pilot scale fluidized bed reactor for removal of a textile dye through heterogeneous Fenton process using natural pyrite

The ability of fluidized bed Fenton oxidation of Acid Yellow 36 (AY36) as an azo dye was investigated applying natural pyrite (NP) particles in a recirculating semi-pilot system. X-ray diffraction, scanning electron microscopy and Brunauer–Emmett–Teller techniques were carried out for characterization of the pyrite. The decolorization percentage of AY36 in NP/H2O2 procedure has been noticeably affected by operational conditions. The decolorization percentage of 92% was observed for the AY36 decolorization (15 mg/L) at the optimized conditions as suspension pH 4, 2 mM H2O2 and 0.6 g/L NP after 120 min of the process time. The decolorization rate in whole of the runs obeyed the pseudo-first-order kinetic with proper correlation coefficients (R 2 ≥ 0.98). The low leached iron amount, repeated reusability in the milder pH and the recirculation mode with adequate mix were the substantial benefits of the NP/H2O2 utilization. Schematic of designed fluidized bed reactor for heterogeneous Fenton process.

Pyrolytic temperature dependent conversion of sewage sludge to carbon catalyst and their performance in persulfate degradation of 2-Naphthol

The evolution of oxygen-functioning groups in sewage sludge based carbon is influenced by minerals presented in the raw sludge. In this study, the FeCl3 and polyacrylamide conditioned sludge in real wastewater treatment plant and demineralized sludge were carbonized in the temperature range of 300°C–800°C to investigate the roles of temperature and ash components on the interactions between surface groups conversion and crystalline structure evolution. The temperature-dependent ash effect on the conversion of oxygen containing groups was found by using XPS, Boehm titration, XRD and TPR characterization. The phase transfer of hematite to magnetite promoted the formation of hydrophilic organic groups at 600°C, which may play a significant role on carbon’s adsorptive and catalytic behavior. To gain an in-depth knowledge and understanding, the as-prepared carbon was used as heterogeneous catalyst in persulfate degradation of a model pollutant 2-Naphthol. The use of carbon obtained at 600°C (MC600) can achieve 88.7% and 47% of 2-Naphthol and TOC removal respectively at neutral pH, far higher than that of MC prepared at 300 and 800°C. Further research revealed a strong correlation between adsorptive and catalytic efficiency of MC and its mineral structure, surface functional groups as well as operating pH. The formed hydrophilic oxygen-containing groups at higher temperature of MC600 are responsible for 2-Naphthol retention and the hydrogen bonds in siloxane bridges can easily adsorb persulfate. The pH effect on degradation in the presence of persulfate verified the broad pH operation, which is apparently superior than conducting with traditional heterogeneous Fenton process. The quenching experiments and EPR spectrum were further used to detect the oxidative species SO4- and HO, and confirmed the catalytic role of MC.

Determination of the chemical reaction kinetics using isothermal reaction calorimetry supported by measurements of the gas production rate: A case study on the decomposition of formic acid in the heterogeneous Fenton reaction

One of the most important steps in studying chemical reaction kinetics is to determine a rate law for the reaction. In this paper, a method for the identification of the reaction kinetic model using isothermal calorimetric data and additional measurement of the rate of pressure change in a constant volume of a calorimetric vessel is described. This method can be applied to fairly fast chemical reactions (i.e. those that can be completed within about 2h) that produce gaseous products. The decomposition of formic acid in the heterogeneous Fenton process is employed as a case study to demonstrate the use of the developed method for the kinetic analysis of a complex reaction system. It was found that the rate of decomposition of hydrogen peroxide can be described by the Langmuir–Hinshelwood type of equation in the form r=kCP/(1+KPCP) (where CP is a molar concentration of H2O2) both in the case of the decomposition of the aqueous hydrogen peroxide solution as well as during the oxidation of formic acid. A simple, purely empirical rate equation for the decomposition of formic acid was also proposed.

Solid‐Liquid Interface Based Biphasic Reaction for Nanomaterial Preparation: Bundled CuO Nanorods as an Example and Their Outstanding Photocatalytic Efficiencies

AbstractFor the first time, a novel environmentally friendly solid‐liquid interface based biphasic reaction process for preparation of nanostructured oxide materials was developed. The process was demonstrated to produce bundled CuO nanorods, which were further shown to be an outstanding catalyst for sun‐light assisted heterogeneous Fenton processes for degradation of RhB, a model recalcitrant organic pollutant.

Hydroxylamine Promoted Goethite Surface Fenton Degradation of Organic Pollutants

In this study, we construct a surface Fenton system with hydroxylamine (NH2OH), goethite (α-FeOOH), and H2O2 (α-FeOOH-HA/H2O2) to degrade various organic pollutants including dyes (methyl orange, methylene blue, and rhodamine B), pesticides (pentachlorophenol, alachlor, and atrazine), and antibiotics (tetracycline, chloramphenicol, and lincomycin) at pH 5.0. In this surface Fenton system, the presence of NH2OH could greatly promote the H2O2 decomposition on the α-FeOOH surface to produce ·OH without releasing any detectable iron ions during the alachlor degradation, which was different from some previously reported heterogeneous Fenton counterparts. Moreover, the ·OH generation rate constant of this surface Fenton system was 102-104 times those of previous heterogeneous Fenton processes. The interaction between α-FeOOH and NH2OH was investigated with using attenuated total reflectance Fourier transform infrared spectroscopy and density functional theory calculations. The effective degradation of organic pollutants in this surface Fenton system was ascribed to the efficient Fe(III)/Fe(II) cycle on the α-FeOOH surface promoted by NH2OH, which was confirmed by X-ray photoelectron spectroscopy analysis. The degradation intermediates and mineralization of alachlor in this surface Fenton system were then systematically investigated using total organic carbon and ion chromatography, liquid chromatography-mass spectrometry, and gas chromatography-mass spectrometry. This study offers a new strategy to degrade organic pollutants and also sheds light on the environmental effects of goethite.

Pilot plant fluidized‐bed reactor for degradation of basic blue 3 in heterogeneous fenton process in the presence of natural magnetite

Degradation of basic blue 3 (BB3) was studied in a pilot scale fluidized‐bed reactor (FBR) utilizing natural magnetite (NM) nanostructures for heterogeneous Fenton process. The morphology, structure, and specific surface area of NM nanostructure were determined employing scanning electron microscopy, X‐ray diffraction, X‐ray photoelectron spectroscopy (XPS), and Brunauer‐Emmett‐Teller (BET) methods, respectively. High mass transfer coefficients, continuous operating condition and high reaction rates due to suitable and sufficient contact of phases, can be noted as significant advantages of FBR. Influences of factors, which affect performance of fluidized‐bed heterogeneous Fenton process (NM/H2O2), for instances initial concentration of contaminant and H2O2, initial pH of solution and dosage of catalyst were investigated. At the desired operational condition, pH 5, 4 mM of H2O2, and 2.27 g/L of NM after 190 min, the degradation percentage of 84%. Excess amounts of catalyst dosage and hydrogen peroxide tend to scavenge hydroxyl radicals by H2O2 molecules. Whereas low initial concentration of the dye and low initial solution pH, enhanced the BB3 degradation. Reusability of NM through five successive experiments, demonstrated the acceptable proficiency of NM as catalyst for oxidative BB3 degradation. © 2017 American Institute of Chemical Engineers Environ Prog, 36: 1039–1048, 2017

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.