Degradation Of Diethyl Phthalate Research Articles

The degradation of diethyl phthalate by reduced smectite clays and dissolved oxygen

Reduced smectite clay plays an important role in producing hydroxyl radical (OH) and degrading organic contaminants. In this study, the OH formation was examined in the suspension of reduced clay particles (Red-Na-NAu-2) with oxygen; diethyl phthalate (DEP), a widely detected plasticizer in soils, could be degraded in the reaction system. The results show the reactivity of Red-Na-NAu-2 is related to iron content, reduction extents and particle sizes; the oxidation process of Red-Na-NAu-2 may change structural Fe coordination or even destruct clay morphology. There are two stages in the oxidation process, fast oxidation and slow oxidation, which were closely related to active structural Fe(II) entities (e.g. Fe(II)Fe(II)Fe(II)-OH) and less active structural Fe(II) entities (e.g. Fe(II)Fe(II)-OH), respectively. It was hypothesized that dissolved oxygen could accept electrons from Fe(II) in outer surface layers (tetrahedral layers and at broken edges) based on spectra (FTIR, XPS and EELS) analyses, and inner lattice Fe(II) in octahedral layers could donate electrons to outer surface Fe(III) through one-electron pathway. The findings of this study provide a thorough understanding about the degradation of organic pollutants in subsurface environments, an omitted natural attenuating pathway, which should be important in soil remediation.

The effects of Fe-bearing smectite clays on [rad]OH formation and diethyl phthalate degradation with polyphenols and H2O2

The natural formation of hydroxyl radicals (OH) is important for the attenuation of organic contaminants. In this study, seven model polyphenols were selected to react with four types of smectite clays with varied Fe contents in the presence of H2O2. Diethyl phthalate (DEP) was selected as a model organic contaminant due to its wide distribution in environment. The results show the appearance of Fe-bearing smectite clays can significantly promote ·OH formation with polyphenols and H2O2 under anoxic conditions; clay particle size, the content and location of lattice Fe in smectite clays greatly affect OH formation. Hydrogen bond between phenolic group and smectite surfaces, and cation assisted hydrogen bond between carboxylic group and clay surfaces are important types of complexation. Electrons can be transferred from coordinated polyphenols to structural Fe(III) atoms in tetrahedral layers or at broken edges to form structural Fe(II) and/or semiquinone radicals, both of which can induce H2O2 decomposition to OH. DEP can be degraded by OH attack, and the main products are proposed as phthalic acid, monomethyl phthalate, hydroxyl-diethyl phthalates. Our findings suggest that Fe(III)-bearing smectite clay can be reduced by polyphenol and produce OH in anoxic environments, which can induce organic contaminants transformation.

New insight into the mechanism of peroxymonosulfate activation by sulfur-containing minerals: Role of sulfur conversion in sulfate radical generation

Peroxymonosulfate (PMS) or persulfate activation by sulfur-containing minerals has been applied extensively for the degradation of contaminants; however, the role of sulfur conversion in this process has not been fully explored. In this study, pyrite (FeS2)-based PMS activation process was developed for diethyl phthalate (DEP) degradation, and its underlying mechanisms were elucidated. PMS was found to be efficiently activated by FeS2 for DEP degradation and mineralization, achieving 58.9% total organic carbon removal using 0.5 g/L FeS2 and 2.0 mM PMS. Sulfides were the dominant electron donor for PMS activation, and mediated Fe(II) regeneration to activate PMS on the surface of FeS2 particles. Meanwhile, different sulfur conversion intermediates, such as S52−, S80, S2O32−, and SO32−, were formed from the oxidation of sulfides by Fe(III) and PMS, and determined by X-ray photoelectron spectroscopy and in-situ attenuated total reflectance Fourier transform infrared spectroscopy analysis. SO32− was the dominant sulfur species responsible for sulfate radicals (SO4−) generation by activating PMS directly or activating Fe(III) to initiate a radical chain reaction, which was supported by the electron paramagnetic resonance results. This study highlights the important role of sulfur conversion in PMS activation by pyrite and provides new insights into the mechanism of oxidant activation by sulfur-containing minerals.

New pathways for the biodegradation of diethyl phthalate by Sphingobium yanoikuyae SHJ

Abstract Diethyl phthalate (DEP) is a representative of phthalate esters (PAEs) that are largely used as industrial additives and have become environmental contaminants and endocrine disruptors. A newly isolated bacterial strain Sphingobium yanoikuyae SHJ was found to be capable of degrading DEP very efficiently. Four intermediates during the DEP degradation process were identified to be ethyl methyl phthalate (EMP), monoethyl phthalate (MEP), monomethyl phthalate (MMP) and phthalic acid (PA) using high-performance liquid chromatography tandem high-resolution mass spectrometry (HPLC-HRMS). When there was limited oxygen under SSA conditions, the rates of the further degradation of MEP and PA were slower compared to that under aerobic conditions. Although all intermediates EMP, MEP and MMP eventually decreased or disappeared, the DEP degradation kinetics showed that EMP formed much faster than that of MEP, and MMP appeared after the decreasing of MEP. It is proposed that two DEP degradation pathways must be present in S. yanoikuyae SHJ. The first is DEP → MEP → PA through a sequential hydrolysis process. The second is DEP → EMP → MEP → MMP → PA through a combination of demethylation or trans-esterification with methanol and hydrolysis processes. It is concluded that S. yanoikuyae SHJ has a versatile capability of degrading DEP and will have a great application potential in bioremediation of PAEs-contaminated shallow aquifer.

Carbon and hydrogen isotope fractionation of phthalate esters during degradation by sulfate and hydroxyl radicals

This study investigated 13C and 2H isotope fractionation associated with oxidation of three phthalate esters (PAEs) by radical species, including sulfate radical (SO4−) induced by heat-activated persulfate (PS) and hydroxyl radical (HO) induced by UV/H2O2. For persulfate oxidation at pH = 2 and pH = 7, similar carbon isotope fractionation (εC) but distinct hydrogen isotope enrichment factors (εH) were observed. The UV/H2O2 reaction of three PAEs showed smaller εH values in comparison with persulfate oxidation. The correlation of 2H and 13C fractionation (Λ) allows to distinguish the persulfate oxidation (25.7 ± 2.6) and UV/H2O2 oxidation (2.4 ± 0.2) of diethyl phthalate (DEP) highlighting the potential of compound-specific stable isotope analysis (CSIA) to characterize chemical oxidation mechanism of PAEs. Moreover, study of radical quenching and CSIA were combined to explore the dominant radical species during persulfate oxidation of DEP. SO4− was found to be the predominant radical at pH = 2. Both SO4− and HO contributed to DEP degradation at pH = 7 and HO was estimated to have a contribution of 21–63% according to dual CH isotope fractionation values. Carbon and hydrogen apparent kinetic isotope effects (AKIEs) (13C-AKIE = 1.017, 2H-AKIE = 2.41) obtained from dominating sulfate radical reaction of DEP both supported the hypothesis of CH bond cleavage. Thus, carbon and hydrogen isotope enrichment factors clearly distinguish the different reaction mechanisms and hence, are a promising approach to improve understanding of radical species reaction pathways for chemical oxidation of PAEs.

Catalytic ozonation of diethyl phthalate in aqueous solution using graphite supported zinc oxide

Abstract Diethyl phthalate (DEP) degradation by graphite supported metal oxide catalytic ozonation in aqueous solution was conducted. The activity and stability of graphite supported ZnO (ZnO/graphite) catalyst, the effects of preparation parameters and operational conditions on the activity of ZnO/graphite, and the mechanism of DEP degradation by ZnO/graphite catalytic ozonation were studied. ZnO/graphite has the highest activity on ozonation of DEP among the MnOx, FeOx, CrOx, CoOx, NiOx and ZnO supported on graphite catalysts, and it keeps excellent catalytic activity during reuse. ZnO/graphite catalyst prepared with 3.5% loading of zinc and calcined at 573 K in N2 atmosphere has the highest activity, and the rodlike ZnO nanoparticles are formed on the graphite surface. The ZnO/graphite catalyst dose, the ozone dose and the initial solution pH exert positive effect on ozonation of DEP. The presence of ZnO/graphite enhances the utilization efficiency of ozone from 52.1% (ozonation alone) to 72.1%, and reduces more than half of the apparent activation energy for ozonation of DEP. It is proposed that the DEP oxidation occurs both in bulk solution and on the surface of ZnO/graphite catalyst, and OH plays a key role in bulk solution.

A Mechanistic Understanding of Hydrogen Peroxide Decomposition by Vanadium Minerals for Diethyl Phthalate Degradation.

The interaction of naturally occurring minerals with H2O2 affects the remediation efficiency of polluted sites in in situ chemical oxidation (ISCO) treatments. However, interactions between vanadium(V) minerals and H2O2 have rarely been explored. In this study, H2O2 decomposition by various vanadium-containing minerals including V(III), V(IV), and V(V) oxides was examined, and the mechanism of hydroxyl radical (•OH) generation for contaminant degradation was studied. Vanadium minerals were found to catalyze H2O2 decomposition efficiently to produce •OH for diethyl phthalate (DEP) degradation in both aqueous solutions with a wide pH range and in soil slurry. Electron paramagnetic resonance (EPR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) analyses, and free radical quenching studies suggested that •OH was produced via single electron transfer from V(III)/V(IV) to H2O2 followed a Fenton-like pathway on the surface of V2O3 and VO2 particles, whereas the oxygen vacancy (OV) was mainly responsible for •OH formation on the surface of V2O5 particles. This study provides new insight into the mechanism of interactions between vanadium minerals and H2O2 during H2O2-based ISCO.

Degradation of diethyl phthalate (DEP) by UV/persulfate: An experiment and simulation study of contributions by hydroxyl and sulfate radicals

Degradation of diethyl phthalate (DEP) by ultraviolet/persulfate (UV/PS) process at different reaction conditions was evaluated. DEP can be degraded effectively via this process. Both tert-butyl (TBA) and methanol (MeOH) inhibited the degradation of DEP with MeOH having a stronger impact than TBA, suggesting sulfate radical (▪) and hydroxyl radical (HO) both existed in the reaction systems studied. The second-order rate constants of DEP reacting with ▪ and HO were calculated to be (6.4±0.3)×107 M−1s−1 and (3.7±0.1)×109 M−1s−1, respectively. To further access the potential degradation mechanism in this system, the pseudo-first-order rate constants (ko) and the radical contributions were modeled using a simple steady-state kinetic model involving ▪ and HO. Generally, HO had a greater contribution to DEP degradation than ▪. The ko of DEP increased as PS dosages increased when PS dosages were below 1.9 mM. However, it decreased with increasing initial DEP concentrations, which might be due to the radical scavenging effect of DEP. The ko values in acidic conditions were higher than those in alkaline solutions, which was probably caused by the increasing concentration of hydrogen phosphate (with higher scavenging effects than dihydrogen phosphate) from the phosphate buffer as pH values rose. Natural organic matter and bicarbonate dramatically suppressed the degradation of DEP by scavenging ▪ and HO. Additionally, the presence of chloride ion (Cl−) promoted the degradation of DEP at low Cl− concentrations (0.25–1 mM). Finally, the proposed degradation pathways were illustrated.

Transition metals (Mn, Ni, Co) doping in TiO2 nanoparticles and their effect on degradation of diethyl phthalate

Transition metal-doped TiO2 nanoparticles are synthesized by sol–gel method. The as-prepared samples are characterized by various techniques to correlate structural and optical properties with chemical nature of dopants and their effect on photocatalytic degradation of diethyl phthalate esters. X-ray diffraction (XRD) reveals that all the samples are crystalline and exhibit anatase as a major phase. Chemical nature of dopants could not affect the formation of anatase and its volume fraction. The crystallite size of undoped and doped TiO2 nanoparticles varies between 10 and 12 nm as confirmed by XRD and transmission electron microscope. The lowest optical band gap observed is 2.47 eV in Mn-doped TiO2. Among all the samples, Ni-doped TiO2 sample shows better photocatalytic activity and degradation of diethyl phthalate due to its lower crystallite size and higher surface area than those of Mn- and Co-doped TiO2 samples.

Preparation and Application of Immobilized Surfactant-Modified PANi-CNT/TiO₂ under Visible-Light Irradiation.

Hydrothermally and sol-gel-synthesized immobilized surfactant-modified polyaniline-carbon nanotubes/TiO2 (PANi-CNT/TiO2) photocatalysts were prepared and their application in the degradation of diethyl phthalate (DEP) under visible light at 410 nm was investigated in this sturdy. To improve the dispersion of nanoparticles and the transfer of electrons, the TiO2 surface was modified with both sodium dodecyl sulfate (SDS) and functionalized carbon nanotubes (CNT-COOH and CNT-COCl). With the addition of PANi, which was increased from 1–5%, the adsorption edge of the prepared photocatalysts shifted to 442 nm. The SDS linked the PANi polymers to achieve a thickness of coating of the film of up to 314–400 nm and 1301–1600 nm for sol-gel hydrolysis and hydrothermally-synthesized photocatalysts, respectively. An appropriate film thickness would extend the transfer path of the electrons and inhibit the recombination of the electrons and the electron-holes. The photo-degradation performance of DEP by the hydrothermally-synthesized photocatalysts was better than those by sol-gel hydrolysis. The results revealed that the hydroxyl radicals were the key oxidant in the degradation of DEP using hydrothermally-synthesized PANi-CNT/TiO2 photocatalysts. The morphology and functional groups of the raw materials of photocatalysts were characterized and a comparison of photocatalytic activity with other TiO2-based photocatalysts was also provided.

Photogeneration of reactive oxygen species from biochar suspension for diethyl phthalate degradation

In this study, the photogeneration of reactive oxygen species (ROS) from biochar suspension was investigated. The characterizations of biochar particles before and after photochemical reactions were analyzed by using FTIR, Raman, XPS and electron paramagnetic resonance (EPR) techniques. It was found that the model pollutant diethyl phthalate (DEP) was efficiently degraded and partially mineralized under UV and simulated solar lights in biochar suspension, with hydroxyl radicals (OH) and singlet oxygen (1O2) as the dominant ROS. EPR coupled with chemical probe methods and free radical quenching studies were used to quantify and elucidate the formation mechanism of OH and 1O2. The results indicated that biochar carbon matrix (BCM) accounted for 63.6%–74.6% of OH and 10%–44.7% of 1O2 formation, while dissolved organic matter (DOM) derived from biochar generated 46.7%–86.3% of 1O2 and 3.7%–12.5% of OH. BCM-bound persistent free radicals (BCM-PFRs) and quinone-like structure of BCM (BCM-Q) were the predominant factors affecting OH and 1O2 formation from BCM under light. Detailed ROS generation pathways are proposed as: (i) DOM from biochar particles contributes to OH and 1O2 formation via light-induced energy and electron transfer processes; (ii) BCM-Q forms excited triplet states (3[BCM-Q]*) under light irradiation and induces the formation 1O2; (iii) UV promotes the formation of BCM-PFRs, which transfer electrons to oxygen to form superoxide anion radical (O2−), further yielding H2O2; and (iv) H2O2-dependent pathways including BCM-PFRs activation and photo-Fenton reaction are primarily responsible for OH production. Furthermore, BCM exhibits the excellent reusability towards DEP degradation during the three cycles under light.

LiCoPO4 (LCP) as an effective peroxymonosulfate activator for degradation of diethyl phthalate in aqueous solution without controlling pH: Efficiency, stability and mechanism

LiCoPO4 (LCP) synthesized particles, which used a conventional solid-state method, were applied as activators for the first time to activate peroxymonosulfate (PMS) with diethyl phthalate (DEP) as the target pollutant. Contrast tests presented that LCP possessed excellent ability of activating PMS for pollutant removal without controlling pH. About 98.6% of DEP could be removed in 6min with 0.1gL−1 LCP and 0.15gL−1 PMS. Rating under different concentrations of Co2+ and leaching solution, activation tests indicated that LCP/PMS system involved in heterogeneous and homogeneous reaction. To reduce the homogeneous effect of Co2+ ions, LCP dose decreased to 0.01gL−1, and the time for entire removal of DEP was extended to 60min. Technologies such as Scanning electron microscope (SEM), X-ray diffraction (XRD), Raman and X-ray photoelectron spectroscopy (XPS) were employed to characterize the particles before and after the reaction. It was found that characterizations of samples had little change and that the DEP removal efficiencies showed no significant reduction after 3 cycles. Sulfate radicals and hydroxyl radicals existed together to make great contributions. This study presented the proposed mechanism of radical production in LCP/PMS system for the DEP removal. Co2+/Co3+ cycle in heterogeneous surface and homogeneous solution play important roles in the process of PMS activation. This report would help to understand the mechanism of PMS activation on LCP and offered an alternative environment-friendly scheme for pollutant removal.

Nanorod ZnO/SiC nanocomposite: An efficient catalyst for the degradation of an endocrine disruptor under UV and visible light irradiations

Endocrine disruptors (EDCs) are emerging environmental contaminants and highly toxic to the human beings, plants and animals. Heterogeneous photocatalytic oxidations have been received renewed interest due to its efficacy in the degradation of endocrine disruptors such as Diethyl phthalate (DEP) and other toxic organic compounds. Nanorod ZnO/SiC nanocomposite were synthesized by a simple sol-gel method and exhibiting an enhanced UV and visible light photocatalytic efficiencies. The prepared photocatalyst were characterized by UV-DRS, XRD, FT-IR, FE-SEM, EDAX, AFM, HR-TEM, XPS and EPR. The UV-DRS results suggested that the band gap was 3.019eV for the prepared photocatalyst. The experimental results proved that the prepared photocatalyst were highly crystalline, nanosized, high roughness, porosity and possess absorption in the UV and visible light regions. Neutral pH was found to be optimum for the effective degradation of the DEP. A catalyst dosage of 5mg and 10mg/10ml resulted in higher percentage of degradation under UV and visible light irradiations respectively. The photo degradation process followed a pseudo first order kinetics and was continuously monitored by UV–vis absorbance measurement and COD analysis. The degradation of DEP was above 90% under UV and visible light irradiations employing nanorod ZnO/SiC nanocomposite as photo catalyst. The stability of the photocatalyst has also been tested its reusability and it was found that upto three cycle of operation the catalyst retain its activity. Hence, the prepared material may find wider applications in environmental remedial technologies to remove the toxic organic and inorganic compounds present in the industrial wastewater.

Performance and Microbial Community Analysis of Bioaugmented Treatment of Diethyl Phthalate (DEP) in Membrane Bioreactor

To enhance the degradation of DEP, the DEP-degrading bacterium Arthrobacter sp. LMS13 isolated from activated sludge was inoculated in MBR reactor to investigate the DEP removal efficiency. At the same time, the real-time quantitative PCR and Illumina MiSeq high-throughput sequencing techniques were employed to detect the changes of phthalate dioxygenase gene (phtA) and the bacterial community structure in the process of reactor operation. The results showed that bioaugmented system shortened the start-up time, and the DEP removed rate of bioaugmented system and unbioaugmented system was 81% and 19%, at concentration of 800 mg·L-1, respectively. PhtA copies increased during domestication, but dropped when DEP concentration exceeded 400 mg·L-1. The phtA gene abundance and DEP removal rate were positively correlated. Bacteria community analysis showed that, along with the operation of reactor, the abundance of phylum of Bateroidetes and Firmicutes reduced, ε-Proteobacteria and Chloroflexi gradually disappeared in the system; on the contrary, β-Proteobacteria and Actinobacteria became the dominant phyla in reactor. Rhodocyclus, Bordetella and Arthrobacter were dominant in the DEP degradation system, and probably maintained the stable operation of reactor.

Effects of clay minerals on diethyl phthalate degradation in Fenton reactions

Phthalate esters are a group of plasticizers, which are commonly detected in China's soils and surface water. Fenton reactions are naturally occurring and widely applied in the degradation of contaminants. However, limited research was considered the effects of clay minerals on contaminants degradation with OH oxidation. In this study, batch experiments were conducted to investigate the degradation of diethyl phthalate (DEP) in Fenton reactions in the presence of clay minerals, and the effects of clay type, Fe content in clay structure. The results showed the clay adsorption inhibited total degradation of DEP, and Fe content in clay structure played an important role in DEP degradation, including in solution and adsorbed in clay minerals. Clay minerals with less Fe content (<3%) quenched OH radical, while nontronite with Fe content 19.2% improved OH radical generation and accelerated DEP degradation in solution. The degradation of clay-adsorbed DEP was much slower than DEP in solution. Six main products of DEP degradation were identified, including monoethyl phthalate, phthalate acid, hydroxyl diethyl phthalate, etc. This study implied that phthalate ester's degradation would be much slower in natural water than expected in the presence of clay minerals.

Electrochemical Degradation of Diethyl Phthalate under Different Operating Conditions

Electrochemical Degradation of Diethyl Phthalate under Different Operating Conditions

Catalytic degradation of diethyl phthalate in aqueous solution by persulfate activated with nano-scaled magnetic CuFe2O4/MWCNTs

Diethyl phthalate (DEP), a plasticizer widely used in chemical industry, has been classified as an endocrine disruptor. Therefore, it is urgent to develop methods for degradation of DEP to minimize its ecological risk. In this study, copper ferrite decorated multi-walled carbon nanotubes magnetic nanoparticles (CuFe2O4/MWCNTs MNPs) were prepared by sol–gel combustion method as catalysts for the degradation of DEP. The catalysts were characterized by scanning electron microscope, transmission electron microscope, Fourier transform infrared spectroscopy, nitrogen gas uptake, X-ray diffraction, and X-ray photoelectron spectroscopy. Catalytic degradation of DEP by persulfate (PS) was investigated with various influencing factors including catalyst loading, PS concentrations, temperature and pH. Furthermore, the CuFe2O4/MWCNTs MNPs showed high catalytic activity, stability and recyclability in DEP removal. Especially, leaching of metal ions from reused CuFe2O4/MWCNTs was negligible (concentration<0.4%), indicating the resistance to oxidation. The electron paramagnetic resonance analysis confirmed that the addition of CuFe2O4/MWCNTs into PS system can accelerate the generation of OH and SO4−, and the quenching experiments further certified the catalytic reaction was predominated by SO4−. The degradation intermediates were identified and the pathways were proposed. Overall, this study provides practical knowledge for DEP removal by CuFe2O4/MWCNTs activated PS at ambient temperature.

Photodegradation of diethyl phthalate with PANi/CNT/TiO2 immobilized on glass plate irradiated with visible light and simulated sunlight—effect of synthesized method and pH

Diethyl phthalate (DEP) is one of the most common phthalates for industrial use and has widely spread in environment. A series of PANi/CNT/TiO2 potocatalysts immobilized on glass plate irradiated with visible light were presented to degrade DEP in this study. The PANi/CNT/TiO2 potocatalysts were fabricated by co-doping with polyaniline (PANi) and two functionalized CNT (CNT-COCl and CNT-COOH) onto TiO2 followed by a hydrothermal synthesis and a sol–gel hydrolysis. Doping of PANi resulted in the absorption edge of the fabricated potocatalysts shifting to 421–437nm and the most distinguished red-shift effect was found in hydrothermal synthesized photocatalysts. The best DEP degradation of 41.5–59.0% and 44.5–67.4% was found in the simulated sunlight system irradiated for 120min for sol–gel hydrolysis PANi/CNT/TiO2 photocatalysts and hydrothermal synthesized ones, respectively. The optimum pH was determined at 5.0 and 7.0 for the two PANi/CNT/TiO2 photocatalysts mentioned above, respectively. The reusability of the sol–gel hydrolyzed photocatalysts up to 5 times was observed no decline in the photodegradation efficiency but less photocatalytic stability of the hydrothermal synthesized ones was found. Meanwhile, the active species of OH radicals generated in the DEP degradation system was identified by free radical scavenging experiments.

Fenton’s Oxidation Kinetics, Pathway, and Toxicity Evaluation of Diethyl Phthalate in Aqueous Solution

AbstractA comprehensive study of the chemical oxidation degradation of diethyl phthalate (DEP) was conducted through Fenton processes. Effects of various operating parameters that considerably affect DEP decomposition were investigated, including solution pH, H

Electro-peroxone degradation of diethyl phthalate: Cathode selection, operational parameters, and degradation mechanisms

This study compares the degradation of diethyl phthalate (DEP) by the electro-peroxone (E-peroxone) process with three different carbon-based cathodes, namely, carbon-polytetrafluorethylene (carbon-PTFE), carbon felt, and reticulated vitreous carbon (RVC). Results show that the three cathodes had different electrocatalytic activity for converting sparged O2 to H2O2, which increased in order of carbon felt, RVC, and carbon-PTFE. The in-situ generated H2O2 then reacts with sparged O3 to yield OH, which can in turn oxidize ozone-refractory DEP toward complete mineralization. In general, satisfactory total organic carbon removal yields (76.4–91.8%) could be obtained after 60min of the E-peroxone treatment with the three carbon-based cathodes, and the highest yield was obtained with the carbon-PTFE cathode due to its highest activity for H2O2 generation. In addition, the carbon-PTFE and carbon felt cathodes exhibited excellent stability over six cycles of the E-peroxone treatment of DEP solutions. Based on the intermediates (e.g., monoethyl phthalate, phthalic acid, phenolics, and carboxylic acids) identified by HPLC-UV, plausible reaction pathways were proposed for DEP mineralization by the E-peroxone process. The results of this study indicate that carbon-based cathodes generally have good electrocatalytic activity and stability for application in extended E-peroxone operations to effectively remove phthalates from water.