Mediated Electrochemical Oxidation Research Articles

Assessing Iron Complexation by Dissolved Organic Matter Using Mediated Electrochemical Oxidation

Assessing Iron Complexation by Dissolved Organic Matter Using Mediated Electrochemical Oxidation

Unraveling Multiple Pathways of Electron Donation from Phenolic Moieties in Natural Organic Matter.

Natural organic matter (NOM) exhibits a distinctive electron-donating capacity (EDC) that serves a pivotal role in the redox reactions of contaminants and minerals through the transformation of electron-donating phenolic moieties. However, the ambiguity of the molecular transformation pathways (MTPs) that engender the EDC during NOM oxidation remains a significant issue. Here, MTPs that contribute to EDC were investigated by identifying the oxidized products of phenolic model compounds and NOM samples in direct or mediated electrochemical oxidation (DEO or MEO, respectively) using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). It was found that the oxidation of newly formed phenolic-OH (ArOH) and the oxidative coupling reaction of the phenoxy radical are the main MTPs that directly contribute to EDC, in addition to the transformation of hydroquinones to quinones. Notably, the oxidative coupling reaction of ArOH contributed at least 22-42% to the EDC. Ferulic acid-like structures can also directly contribute to EDC by incorporating H2O into their acrylic substituents. Furthermore, the opening of C rings can indirectly attenuate the EDC through structural alterations in the electron-donating process of NOM. Decarboxylation can either weaken or enhance the EDC depending on the structure of the phenolic moieties in NOM. These findings suggest that the EDC of NOM is a comprehensive result of multiple NOM MTPs, involving not only ArOH oxidation but also the addition of H2O to olefinic bonds and bond-breaking reactions. Our work provides molecular evidence that aids in the comprehension of the multiple EDC-associated transformation pathways of NOM.

Influence of Organic Ligands on the Redox Properties of Fe(II) as Determined by Mediated Electrochemical Oxidation.

Fe(II) has been extensively studied due to its importance as a reductant in biogeochemical processes and contaminant attenuation. Previous studies have shown that ligands can alter aqueous Fe(II) redox reactivity but their data interpretation is constrained by the use of probe compounds. Here, we employed mediated electrochemical oxidation (MEO) as an approach to directly quantify the extent of Fe(II) oxidation in the absence and presence of three model organic ligands (citrate, nitrilotriacetic acid, and ferrozine) across a range of potentials (EH) and pH, thereby manipulating oxidation over a broad range of fixed thermodynamic conditions. Fe(III)-stabilizing ligands enhanced Fe(II) reactivity in thermodynamically unfavorable regions (i.e., low pH and EH) while an Fe(II) stabilizing ligand (ferrozine) prevented oxidation across all thermodynamic regions. We experimentally derived apparent standard redox potentials, EHϕ, for these and other (oxalate, oxalate2, NTA2, EDTA, and OH2) Fe-ligand redox couples via oxidative current integration. Preferential stabilization of Fe(III) over Fe(II) decreased EHϕ values, and a Nernstian correlation between EHϕ and log(KFe(III)/KFe(II)) exists across a wide range of potentials and stability constants. We used this correlation to estimate log(KFe(III)/KFe(II)) for a natural organic matter isolate, demonstrating that MEO can be used to measure iron stability constant ratios for unknown ligands.

Electrochemical Degradation of Methylene Blue using Ce(IV) Ionic Mediator in the Presence of Ag(I) Ion Catalyst for Environmental Remediation

Methylene blue (MB) is often used in textile industries and is actively present in the wastewater runs-off. Recently, mediated electrochemical oxidation (MEO) offers a fast, reliable and promising results for environmental remediation. Thus, we aimed to evaluate the electro-degradation potential of MB by MEO using Ce(IV) ionic mediator. Furthermore, we also observed the influence of addition Ag(I) ion catalyst in MEO for degradation of MB. The electro-degradation of MB was evaluated by cyclic voltammetry technique and was confirmed by UV-Vis spectrophotometry, high performance liquid chromatography (HPLC) analysis and back-titration analysis. The results showed that in the absence of Ag(I) ion catalyst, about 89 % of MB was decolorized within 30 min. When 2 mM of Ag(I) ion catalyst was applied, the electro-degradation of MB was increased to maximum value of 100%. The UV-Vis spectrum confirmed the electro-degradation of MB as suggested by decreased maximum absorbance value at λ 668 nm from 2.125 to 0.059. The HPLC analysis showed the formation of five new peaks at retention time of 1.331, 1.495, 1.757, 1.908, and 2.017 min, confirming the electro-degradation of MB. The back-titration analysis showed about 52.9% of CO2 was produced during electro-degradation of MB by MEO. More importantly, more than 97% of Ce(IV) ionic mediator were recovered in our investigation. Our results showed the potential of MEO using Ce(IV) ionic mediator to improve the wastewater runs-off quality from textile as well as other industries containing methylene blue.

ENHANCING THE DEGRADATION POTENTIAL OF INDIGO CARMINE BY A MEDIATED ELECTROCHEMICAL OXIDATION USING Ce4+ MEDIATOR AND Ag+ CATALYST IONS

Wastewater runoff containing hazardous dyes must be treated properly before being discharged into the environment. Indigo carmine (IC), a kind of dye, has been recognized to be potentially toxic. In this work, mediated electrochemical oxidation (MEO) using cerium (Ce4+) mediator ions incorporated with an Ag+ catalyst ion was tested to treat IC solution in a reactor as a simulation. The experimental results demonstrated that the IC molecules can be degraded quickly in a relatively short time by MEO. It was clearly shown that the degradation performance of IC by MEO was affected by the Ce2(SO4)3 concentration, working potential, time, and catalyst ion concentration as well. In addition, the high percentage recovery of Ce4+ proves the reusability of Ce4+ as a mediator ion. As an outstanding result, the percentage degradation of IC using Ce4+ /Ag+ ions was remarkably higher than that without Ce4+ mediator ions (100% vs 2%). In summary, our work suggests that MEO using a combination of Ce4+ mediator and Ag+ catalyst ion has great potential to improve the wastewater quality

Electrochemical and Structural Modifications of Humic Acids in Aerobically and Anaerobically Incubated Peat

Exposure to oxygen and aerobic biological activity during drought periods alters the availability of terminal electron acceptors (TEA) in the peat catotelm layer. We investigated the changes in the electrochemical and chemical characteristics of humic acids (HA) induced by subjecting air-dried sphagnum peat to biological oxidation or reduction during a 90-day incubation experiment. Structural modifications of HAs from anaerobically (HAred) and aerobically (HAox) incubated peat were investigated by ATR-FTIR, UV–vis, and EEM fluorescence spectroscopy. Number and strength of acid groups were characterized by titration, while changes in redox properties were characterized by cyclic voltammetry and quantified by coulometry with mediated electrochemical oxidation (MEO). Exposure to oxygen had small effects, but compared to anaerobic incubation, decreased by 20% the capacity of HA to reduce the radical ion of 2,2′-Azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS●−), passing from 2.77 ± 0.13 mmole- gHA−1 in HAred to 2.21 ± 0.10 mmole- gHA−1 in HAox. Pseudo-first-order electron transfer kinetic constants were 13.3 ± 1.2 s−1 for HAox and 16.7 ± 1.4 s−1 for HAred. Alterations in the hydrological status of the catotelm have minor effects on the actual in situ availability of organic TEA, but if coupled to intensified biological activity they may result in significant variations of greenhouse gases emissions.

Kinetics of electron transfer reactions by humic substances: Implications for their biogeochemical roles and determination of their electron donating capacity

Humic substances (HS) possess redox active groups covering a wide range of potentials and are used by facultative anaerobic microorganisms as electron acceptors. To serve as suitable electron shuttles for anaerobic respiration, HS should be able to re-oxidize relatively quickly to prevent polarization of the surrounding medium. Mediated electrochemical oxidation and decolorization assays, based on the reduction of the radical ion of 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS•−) allow to determine the electron donating capacity (EDC) of HS, but uncertainties remain about the reaction time that should be allowed to obtain environmentally meaningful EDC values. In this work, we performed a kinetic analysis of the time trend of the reduction of ABTS•− by HS by Vis and Electron Paramagnetic Resonance (EPR) spectroscopies and by cyclic voltammetry. We found evidences of two concomitant separate mechanisms of electron exchange: a fast and a slow transfer processes which may have different environmental roles. These results can set a base to identify the appropriate conditions for the spectrophotometric determination of the fast and slow components of the EDC of HS.

Degradation of Nonylphenol Ethoxylate-10 (NPE-10) by Mediated Electrochemical Oxidation (MEO) Technology

Nonylphenol ethoxylate (NPE-10) is a non-ionic surfactant that is synthesized from alkylphenol ethoxylate. The accumulation of NPE-10 in wastewater will endanger the ecosystem as well as the human being. Nowadays, NPE-10 can be degraded indirectly by using an electrochemical treatment by the advancement of technology. Thus, this study is aimed to evaluate the electro-degradation potential of NPE-10 by MEO using Ce(IV) ionic mediator. In addition, the influence of Ag(I) ionic catalyst in the performance of MEO for the degradation of NPE-10 was also observed. The potency of MEO technology in the NPE-10 degradation was evaluated by voltammetry technique and confirmed by titrimetry and LC-MS analysis. The results showed that in the absence of Ag(I) ionic catalyst, the degradation of NPE-10 by MEO was 85.93%. Furthermore, when the Ag(I) ionic catalyst was applied, the performance of MEO in degradation of NPE-10 was improved to 95.12%. The back titration using Ba(OH)2 confirmed the formation of CO2 by 46.79%, whereas the redox titration shows the total of degradation organic compounds by 42.50%. It was emphasized by the formation of two new peaks in the LC-MS chromatogram. In summary, our results confirmed the potential of MEO technology for the NPE-10 degradation.

Fe distribution, redox state and electrochemical activity in Boom Clay

In the context of radioactive waste disposal in clay formations, the sorption of a number of redox sensitive radionuclides (e.g. U, Se, Tc) is controlled by the presence of Fe-containing minerals, mainly smectite (Guimaraes et al., 2016), illite (Bruggeman and Maes, 2010), and pyrite (Breynaert et al., 2010). In the repository lifetime, oxidizing conditions will prevail during the open drift phase enhanced by ventilation followed by recovery of reducing conditions after back-filling. Thus Fe-containing minerals will be subjected to redox cycles in the course of the repository operation. In order to evaluate the sensitivity of different Fe containing minerals in the Boom Clay to changing redox conditions, Fe2+/Fe3+ partitioning was determined in various size fractions (<0.2, 0.2–2, 2–8 μm) and bulk samples by complexation with phenanthroline and XANES spectroscopy. The integration of the Fe speciation with quantitative mineralogical data allowed for a calculation of Fe redox activities. These values were then compared with the empirical electron accepting capacity (EAC) and electron donating capacity (EDC) values deduced from the mediated electrochemical reduction (MER) and mediated electrochemical oxidation (MEO) experiments. The results indicate that Fe3+ present in the smectite has a major control over the measured EACs in the redox cycled (oxidized, reduced and re-oxidized) Boom Clay samples. Fe2+ in illite and chlorite explain well the measured EDC values in the various size fractions, whereas in bulk samples pyrite and organic matter are the major contributors to EDC. The theoretical electrochemical activities (both EACs and EDCs) are about factor two higher than the experimental values. It is therefore concluded that the electrochemical activities of pure minerals do not necessarily reflect their electrochemical activities in the natural redox cycled samples. The methodological approach presented here may serve as a basis for further electrochemical investigations of natural, redox cycled sediments.

What does mediated electrochemistry reveal about regional differences in the redox properties of Boom Clay?

The Boom Clay is a potential host rock for geological storage of radioactive waste in the Netherlands and Belgium. The redox properties of the host rock are important in the context of safety assessment as they affect the speciation and thus the mobility of redox sensitive radionuclides. In this study, redox properties of the clay were assessed by mediated electrochemical analyses. The electron donating (EDC) and accepting (EAC) capacities and reduction potential of a suite of Boom Clay samples were determined. Boom Clay samples from various locations in the Netherlands and Belgium were investigated in unaltered form, and after size separation or chemical treatment to relate variations in redox properties to regional differences in diagenetic history or in the assemblage of allogenic minerals. In the investigated samples, the EDC can be attributed to the oxidation of pyrite, FeII in clay minerals and reduced natural organic matter (NOM) while the EAC can be ascribed to the reduction of FeIII in clay minerals and in Fe (oxyhydr)oxides. Combining Na-pyrophosphate extraction, to remove reactive NOM, with mediated electrochemical oxidation (MEO) allowed determining the individual EDC of NOM and FeII in clay minerals. Mediated electrochemical analysis showed systematic differences between samples from two locations in the Netherlands, Zeeland and Limburg. In samples from Zeeland, the reduction potential was higher, the EAC was larger, and the contribution of NOM to the EDC was smaller compared to samples from Limburg. These differences can be attributed to partial oxidation of Boom Clay in Zeeland during its diagenetic history but partial oxidation could also be a storage artefact. The electron yield obtained by pyrite oxidation in samples from Zeeland was larger compared to those from Limburg, which can be explained by a smaller particle size of pyrite in Zeeland. The size of pyrite particles, in turn, can be used as a proxy for the depositional conditions. The electrochemical activity of Fe in clay minerals did not vary systematically between the two locations in the Netherlands. In general, the fraction of electrochemically active Fe in clay minerals increased with the relative content of 2:1 clay minerals. In comparison with samples from the Netherlands, larger fractions of structural Fe in clay minerals were redox-active in samples from Belgium, which had a higher chlorite or glauconite content. This study demonstrates that mediated electrochemical analysis can reveal redox properties of Boom Clay, which might be of relevance for the migration of redox sensitive radionuclides or when assessing the impact of constructing and operating a repository for nuclear waste on the surrounding host rock.

Degradation of sulfamethazine by cerium mediated photoelectrochemical oxidation with hydroxyl radical oxidation effect

A cerium (Ce) mediated photoelectrochemical oxidation (MPEO)/H2O2 system, integrating UV photocatalysis and hydroxyl radical (⋅OH) oxidation, was developed to improve the degradation of sulfamethazine (SMT). SMT is an emerging contaminant with medical toxicity in environmental matrices. In the study of electrolytic production of Ce(IV), the Ce(III)/Ce(IV) redox reaction was found to have good reversibility at high HNO3 concentrations above 0.5 M, due to more cerium ions being trapped by NO3- ions near the anode. In addition, optimum current density of 8 mA cm−2 and reaction temperature of 313 K, for Ce(IV) production, are determined by considering specific energy consumption (SEC) and Ce(IV) percent yield. The MPEO/H2O2 system demonstrates favorable SMT removal efficiencies of 76% and 98%, at treatment times of 60 and 120 min, respectively. This system outperforms the mediated electrochemical oxidation (MEO) and MPEO systems, for SMT degradation. In addition, the kinetics of SMT degradation, using the MPEO/H2O2 system, was found to follow a proposed pseudo-first order model, rather than a pseudo-second order model, and exhibit a higher rate constant than those of the MEO and MPEO systems. Moreover, the concentration of ⋅OH during SMT treatment can be estimated by measuring the concentrations of 4-Hydroxybenzoic acid (4-HBA) and 3,4-Dihydroxybenzoic acid (3,4-DHBA), over time. Our findings reveal that introducing UV irradiation and H2O2 into the MEO system can induce a higher production of ⋅OH in addition to the Ce(IV) ions, thus leading to improved SMT removal efficiency.

Mediated electrochemical oxidation of glucose via poly(methylene green) grafted on the carbon surface catalyzed by flavin adenine dinucleotide-dependent glucose dehydrogenase

Electrochemically polymerized phenothiazines (thionine, methylene green, methylene blue, and toluidine blue) on carbon electrodes were investigated as electron transfer mediators of glucose oxidation by flavin adenine dinucleotide-dependent glucose dehydrogenase (FAD-GDH) for biosensor and biofuel cell applications. Among the tested polyphenothiazines grafted on a glassy carbon electrode, clear redox-mediating activity was observed for poly(methylene green), and the catalytic oxidation current depended on the concentrations of glucose and enzymes and the amount of polymer deposited on the electrode surface. The poly(methylene green)-grafted porous carbon electrodes showed 3 mA cm−2 of glucose oxidation current catalyzed by FAD-GDH.

Photoelectrocatalytic oxidation of phenol by UV-assisted electrogenerated Ce(IV) in aqueous solution

Abstract A UV (UV-C, 254 nm)-assisted Ce(IV) mediated electrochemical oxidation (MEO) system is developed to treat phenol-containing water. For comparison, an individual Ce(IV)-MEO system without UV and a UV photocatalytic oxidation system without applying an electrical current are also evaluated. The operation conditions of electrical current, nitric acid concentration, stirring speed, and electrode area ratio of anode to cathode for Ce(IV) electrogeneration are optimized in terms of percent yield of Ce(IV) and energy consumption. According to the kinetic model of the Ce(IV)/Ce(III) redox reaction, the forward rate constant of Ce(III) oxidation is twice as high as that of the reverse reaction. For the wastewater treatment, Ce(IV)-MEO and photocatalytic oxidation systems both show good capability for degrading phenol in an acidic environment rather than the direct electrochemical oxidation (DEO) system. Importantly, the UV-assisted MEO system exhibits excellent removal efficiency (RE) of phenol (up to 98%) in only 40 min because of the synergistic effect of the electrocatalytic and photocatalytic systems, which individually exhibit REs of

Accurately quantifying the reductive capacity of microbial extracellular polymeric substance by mediated electrochemical oxidation method

The reductive capacity of microbial extracellular polymeric substances (EPS) plays important roles in environmental processes involved in heavy metal detoxification and organic contaminant degradation. However, the crucial parameter to evaluate the reductive capacity of EPS, electron donating capacity (EDC) lacks a quantitative approach. In this study, a novel mediated electrochemical oxidation (MEO) method was developed to investigate the EDCs of microbial EPS extracted from Shewanella oneidensis MR-1 (S. oneidensis MR-1), Escherichia coli (E. coli) and activated sludge. The results indicate that the MEO approach rapidly and accurately quantifies the EDCs of microbial EPS. S. oneidensis MR-1 EPS possessed the highest EDC value ascribed to their specific redox proteins components. EDCs of S. oneidensis MR-1 EPS were dependent on measurement conditions and increased with growing solution pH and applied potential. EDCs of S. oneidensis MR-1 EPS were depleted gradually during the redox reaction with irreversible oxidation of EPS. The reductive property of microbial EPS was accurately evaluated by quantifying the EDCs of EPS using the MEO approach, as well as their potential in environmental remediation.

Onsite quantifying electron donating capacity of dissolved organic matter

Electron donating capacity (EDC) of dissolved organic matter (DOM) impacts the redox behaviors of DOM in surface waters, groundwaters, wetlands, sediments and soils but lacks applicable onsite quantification methods. To address these disadvantages, a simple and portable device with pre-injected [2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonicacid), ABTS·+] was developed that can be used for EDC onsite measurements of DOM in this work. The proposed device and method had better limits of quantification of Trolox (0.2 nmol) and more flexible DOC concentration requirement of 0.5–20 mg L−1 than that of flow injection analysis (FIA) (5–10 mg L−1) or mediated electrochemical oxidation (MEO) (>20 mg L−1). The proposed device and method greatly reduced the preparation and measurement time for sample tests compared to MEO or FIA method, enabling time-efficient EDC determination for large amount of samples. Meanwhile, the proposed device presented comparable accuracy with established MEO method when quantifying the EDCs of 7 standard humic and fulvic acids. Humic acids with higher molecular weight (MW) (<15,000 Da) had higher EDC than that with low MW (<5000 Da). EDCs of DOM in natural and reclaim water samples were both presented significantly positive correlations with their corresponding chemical oxygen demand, chromophoric DOM content, molecular weight and humification of the DOM in water samples. These results suggested that our device could accurately quantify the EDCs of DOM onsite and had promising applications on the fast quality assessment of natural and reclaimed waters.

Cyclic Voltammetry Study of Mediated Electrochemical Oxidation Using Platinum Wire, Pt/Co(OH)2 and Pt/Co Electrodes In Various Supporting Electrolytes

&lt;p&gt;Amoxicillin is one of β-lactam antibiotic in penicillin groups which their presence in surface water and wastewater not only affects water quality but also causes long-term adverse effects on ecosystems and human health due to their resistance to natural biodegradation. The processing of organic waste electrochemically has the advantage of cheap and efficient cost, exhaust gas that does not contain toxic and hazardous materials. We have studied the process of amoxicillin electro-oxidation mediated by a cobalt (III) ion called an electrochemical oxidation process mediated (MEO) in a voltammetry study using a platinum working electrode, Pt/Co(OH)&lt;sub&gt;2&lt;/sub&gt; and Pt/Co in various supporting electrolytes such as KNO&lt;sub&gt;3&lt;/sub&gt;, NaClO&lt;sub&gt;4&lt;/sub&gt;, Na&lt;sub&gt;2&lt;/sub&gt;SO&lt;sub&gt;4&lt;/sub&gt; and phosphate buffer solution with concentrations 0.10 M. The results show that the amoxicillin oxidation peaks using the above-mentioned working electrode in various electrolyte solutions are in the potential range of 500-670 mV (Ag/AgCl). The presence of cobalt ions forming complex compounds with amoxicillin causes the oxidation current decreasing that indicates the presence of degradation to amoxicillin.&lt;/p&gt;

Continuous N-Hydroxyphthalimide (NHPI)-Mediated Electrochemical Aerobic Oxidation of Benzylic C-H Bonds.

Electroorganic chemistry has emerged as an environmentally benign tool for synthetic chemists to achieve efficient transformations that are challenging with traditional reagent-based methods. Continuous flow chemistry brings pharmaceutical industry numerous advantages, but implementing electroorganic synthesis in flow is challenging, especially for electroorganic reactions with coupled electrode reactions and slow chemical reactions. We present a continuous electrolysis system engineered for N-hydroxyphthalimide (NHPI) mediated electrochemical aerobic oxidation of benzylic C-H bonds. First, a cation-exchange membrane prevents the crossover of the NHPI anion from anolyte to catholyte avoiding reductive decomposition of NHPI at the cathode, and enables the usage of a cost-effective reticulated vitreous carbon (RVC) cathode instead of a platinum electrode. Second, running the electrochemical flow cell with recycle streams accommodates the inherently slow kinetics of the chemical reaction without phthalimide-N-oxyl (PINO) radical self-decomposition at the anode, and allows the usage of gaseous oxygen as co-oxidant.

Surface modification of vulcanized EPDM rubber by Ag (II): Kinetic study of Ag (II) generation and surface characterization

Ethylene propylene diene monomer (EPDM) rubber has been widely used in the various outdoor and industrial applications. However, in order to improve its adhesion properties it needs some surface modification. Mediated electrochemical oxidation by Ag (II) was thus employed to evaluate the feasibility of EPDM surface modification. The electrochemical behavior of Ag (I) /Ag (II) redox couple was initially studied at different temperatures in an electro-membrane cell using IrO2/Ta2O5anode. The reversibility of the redox reaction improved at low temperatures. The apparent rate constant for Ag (I) oxidation (k1) at 3 kA m-2 was (s-1). The surface chemistry, morphology and wettability of the activated EPDM rubber by Ag (II) were then analyzed and the modified EPDM surface showed a significant decrease in the water contact angle resulting in an increase in the surface free energy and improved wettability. ATR analysis revealed presence of oxygen-containing polar groups on the modified rubber surface. SEM results showed that the short treatment time at room temperature only changed the morphology of the rubber surface, which is attributed to the etching of the outermost surface.

Mediated electrochemical oxidation (MEO) process: a study on nonylphenol ethoxylates (NPE) oxidation in batch mode using cerium (IV) oxidant

Nonylphenol ethoxylate (NPE-10) is one type of non-ionic surfactants from the class of alkylphenol ethoxylate (APE). This compound is already tightened their use in European Union countries. However, these surfactants are still used widely in Indonesia because the price is relatively cheap. Consequently, these compounds can accumulate in aquatic environments. NPE-10 can disrupt aquatic ecosystems. This study aimed to describe the electro-oxidation process of NPE-10 based on the parameters of a potential difference, concentration of NPE-10, concentration of Ce (III), and oxidation time. The result of oxidation NPE-10 was measured by the amount of current generated from voltammetry technique. Studies of cyclic voltammetry using carbon paste electrodes illustrates the potential value of the oxidation of Ce (III) / Ce (IV) of 1.25 V and the reduction potential value of Ce (IV) / Ce (III) of 1.192 V. NPE-10 are electroactive irreversible because it only provides the potential value of oxidation at 1.44 V. Percent of total degradation of 84.96% was obtained at electro-oxidation of 500 ppm NPE-10 by the addition of 0.015 M Ce (III) for 90 minutes at 0.2 M H2SO4and the use of potential of 6 V.

Mediated Electrochemical Oxidation of Pollutants in Crude Oil Desalter Effluent

Mediated Electrochemical Oxidation of Pollutants in Crude Oil Desalter Effluent