Fenton's Reagent Treatment Research Articles

Removal of Tetracycline Antibiotic from Wastewater by Fenton Oxidation Process

This study aimed to remove the antibiotic tetracycline from a sample of synthetic wastewater using an advanced oxidation process by Fenton's reagent treatment. Central Composite Design (CCD) software was used to reduce the number of tests required to remove tetracycline. The independent variables identified in batch oxidation experiments are the concentrations of tetracycline (40–250 mg / L), hydrogen peroxide (20–600 mg / L), and Fe(II) (0–60 mg / L). The rate of tetracycline degradation was significantly influenced by the concentration of hydrogen peroxide and tetracycline. The reaction time required for tetracycline removal was determined to be 15 minutes. The optimal ratio of independent variants leading to complete degradation 100% of tetracycline was hydrogen peroxide / Fe2 + / tetracycline 310/30/145 mg / l.

Insight into the fenton-induced degradation process of extracellular polymeric substances (EPS) extracted from activated sludge

Although EPS in microbial aggregates are importance in successful implementation of biological wastewater treatment systems, they also exhibit detrimental role on certain circumstance, such as excess sludge dewatering. Extensive efforts have been put into the disruption of EPS for improving the dewaterability of excess sludge and Fenton's reagent treatment has been demonstrated to be a very promising sludge conditioning method for EPS destruction. However, the information regarding detailed degradation process of EPS during Fenton's reagent treatment is limited. In this study, EPS were extracted from activated sludge and treated with different concentrations of Fenton's reagent. The physicochemical characteristic changes of EPS under different treatment were investigated in terms of components, EEM, molecular weight (MW), UV-Vis and FTIR. The results showed that EPS were prone to be disintegrated, but hard to be fully mineralized. Humic substances in EPS were more resistant to Fenton's reagent than other components. Low MW components of EPS were preferentially degraded prior to the disruption of high MW components. Besides, the disintegration of EPS into lower MW ones was accompanied by the formation of higher MW compounds caused by the bridge interaction of Fe ions. The cleavage of protein's backbone in EPS was mainly through destruction of amide II (N–H and C–N) in –CO–NH–. Fenton's reagent treatment also led to a significant increase of oxygen-containing functional groups in EPS molecules. This paper may pave a path to deeply understand the mechanisms of dewatering improvements of excess sludge by Fenton's conditioning.

Multiphase Porous Electrochemical Catalysts Derived from Iron-Based Metal-Organic Framework Compounds.

Herbicide use has attracted attention recently due to potential damage to human health and lethality to the honey bees and other pollinators. Fenton reagent treatment processes can be applied for the degradation of herbicidal contaminants from water. However, the need to carry out the normal Fenton reactions under acidic conditions often hinders their practical application for pollution control. Herein, we report on the synthesis and application of multiphasic porous electro-Fenton catalysts prepared from calcinated metal–organic framework compounds, CMOF@PCM, and their application for the mineralization of herbicides in aqueous solution at circum-neutral pH. CMOF nanoparticles (NPs) are anchored on porous carbon monolithic (PCM) substrates, which allow for binder-free application. H2O2 is electrochemically generated on the PCM substrate which serves as a cathode, while ·OH is generated by the CMOF NPs at low applied potentials (−0.14 V). Results show that the structure and reactivity of the CMOF@PCM electro-Fenton catalysts are dependent on the specific MOF precursor used during synthesis. For example, CMIL-88-NH2, which is prepared from MIL-88(Fe)–NH2, is a porous core–shell structured NP comprised of a cementite (Fe3C) intermediate layer that is sandwiched between a graphitic shell and a magnetite (Fe3O4) core. The electro-Fenton production of hydroxyl radical on the CMOF@PCM composite material is shown to effectively degrade an array of herbicides.

Cellulose Fibers Dissolution in Alkaline Solution

In this study, NaOH dissolution method was applied to dissolve cellulose fibers which extracted from date palm fronds (type Al-Zahdi) taken from Iraqi gardens. In this process, (NaOH)-solution is brought into contact with the cellulose fibers at low temperature. Experiments were conducted with different concentrations of NaOH (4%, 6%, 8% and12%) weight percent at two cooling bath temperatures (-15 oC) and (-20oC). Maximum cellulose dissolution was 23 wt% which obtained at 8 wt% concentration of NaOH and at cooling bath temperature of -20oC. In order to enhance the cellulose fibers dissolution, the sample was pretreated with Fenton's reagent which consists of hydrogen peroxide (H2O2), oxalic acid (C2H2O4) and ferrous sulfate (FeSO4). This reagent reacts with cellulose fibers and produces free radicals which increase cellulose dissolution. In this work three variables were studied: cooling bath temperature (-15oCand-20oC), NaOH concentration (4%, 6%, 8% and12%) and time of Fenton's reagent treatment (1-48) hrs. The results showed that the best percent of cellulose dissolution was (42 wt %) which occurred at treatment time (24 hours), temperature (-20oC) and NaOH concentration 8%. In another set of experiments urea was added to NaOH solution as a catalyst with proportion (6%NaOH+4% urea) at two temperatures -15 and -20 oC. The results show that the solubility of cellulose increase to 62% for the sample which treated with Fenton's reagent and to 35% for the untreated sample, both values were obtained at -15oC.

The characteristics and electrochemical performance of graphite felts with thermal and fenton's reagent treatment for vanadium redox flow battery

In this study, we modified the surface morphology and functional group of graphite felts (GFs) through thermal and Fenton’s reagent treatment. The modified GFs were used as electrodes for vanadium redox flow batteries (VRFBs). Surface morphology, wettability, chemical composition and electrochemical performance of GFs were characterized through contact angle measurement, X-ray photoelectron spectroscopy, cyclic voltammetry, electrochemical impendence spectroscopy, and charge discharge testing. The charge transfer resistance of the GFs after thermal and Fenton’s reagent treatment was lower than that of unmodified GF because of the high specific surface areas and hydroxyl group formation on the surface of the modified GFs. The VRFBs based on GFs modified through thermal and Fenton’s reagent treatment exhibited superior electrochemical performance when comparing with the unmodified GF electrode. The GF with heat treatment at 500 °C for 3 h and Fenton’s reagent treatment had high Coulombic efficiency, voltage efficiency and energy efficiency of 94.84%, 81.77% and 77.55% at 60 mA/cm2, respectively.

Involvement of Fenton chemistry in rice straw degradation by the lignocellulolytic bacterium Pantoea ananatis Sd-1

BackgroundLignocellulolytic bacteria have revealed to be a promising source for biofuel production, yet the underlying mechanisms are still worth exploring. Our previous study inferred that the highly efficient lignocellulose degradation by bacterium Pantoea ananatis Sd-1 might involve Fenton chemistry (Fe2+ + H2O2 + H+ → Fe3+ + OH· + H2O), similar to that of white-rot and brown-rot fungi. The aim of this work is to investigate the existence of this Fenton-based oxidation mechanism in the rice straw degradation process of P. ananatis Sd-1.ResultsAfter 3 days incubation of unpretreated rice straw with P. ananatis Sd-1, the percentage in weight reduction of rice straw as well as its cellulose, hemicellulose, and lignin components reached 46.7, 43.1, 42.9, and 37.9 %, respectively. The addition of different hydroxyl radical scavengers resulted in a significant decline (P < 0.001) in rice straw degradation. Pyrolysis gas chromatography–mass spectrometry and Fourier transform infrared spectroscopy analysis revealed the consistency of chemical changes of rice straw components that exists between P. ananatis Sd-1 and Fenton reagent treatment. In addition to the increased total iron ion concentration throughout the rice straw decomposition process, the Fe3+-reducing capacity of P. ananatis Sd-1 was induced by rice straw and predominantly contributed by aromatic compounds metabolites. The transcript levels of the glucose-methanol-choline oxidoreductase gene related to hydrogen peroxide production were significantly up-regulated (at least P < 0.01) in rice straw cultures. Higher activities of GMC oxidoreductase and less hydrogen peroxide concentration in rice straw cultures relative to glucose cultures may be responsible for increasing rice straw degradation, which includes Fenton-like reactions.ConclusionsOur results confirmed the Fenton chemistry-assisted degradation model in P. ananatis Sd-1. We are among the first to show that a Fenton-based oxidation mechanism exists in a bacteria degradation system, which provides a new perspective for how natural plant biomass is decomposed by bacteria. This degradative system may offer an alternative approach to the fungi system for lignocellulosic biofuels production.Electronic supplementary materialThe online version of this article (doi:10.1186/s13068-016-0623-x) contains supplementary material, which is available to authorized users.

Preparation of Hydroxylated Carbon Nanotubes/Magnetic Iron Oxide Compound Particles

In this paper, hydroxylated CNTs/Fe2O3 precursors were prepared on the basis of Fenton reagent treatment using aqueous ammonia (NH3H2O), sodium carbonate (Na2CO3) and urea (CO(NH2)2) as precipitants. And then three kinds of hydroxylated CNTs/Fe2O3 compound particles were obtained by calcining the precursors at 523K for 2h. The change of hydroxyl group, phase structure, morphology, thermogravimetric behavior, magnetic property and electrical conductivity of the compound particles were investigated, respectively. The results show that hydroxyl groups exist on surface of CNTs, and Fe2O3 particles in composite particles exhibit high purity and integrated crystalline structure. For NH3H2O precipitant, α-Fe2O3 particles is produced with crystallite size of 62.5nm and no saturation magnetization (Ms). For Na2CO3 precipitant, γ-Fe2O3 is produced with crystallite size of 37.6nm and Ms of 10.5emug-1, and the compound particles are drastically agglomerated. For CO(NH2)2 precipitant, γ-Fe2O3 is produced with crystallite size of 35.1nm and Ms is 9.7 emug-1, and the compound particles are homogeneous with the lowest volume resistivity of 100 Ωcm.

Soil remediation using soil washing followed by Fenton oxidation

Soil washing was applied to a contaminated soil with p-Cresol by using a nonionic surfactant (Tween 80). A mathematical model has also been proposed to describe both the pollutant desorption and the surfactant adsorption, taking place simultaneously. The effect of temperature (20–40°C) and surfactant concentration (0.1–10gL−1) have been analyzed on both kinetic rates. The kinetic desorption rate of p-Cresol increases as the initial solubilizer concentration. Desorption of p-Cresol was slightly greater with increasing temperature. The obtained kinetic model represents quite well the experimental results.Soil washing wastewater (20mgL−1 of p-Cresol and 0.86gL−1 of Tween 80) has been treated with Fenton Reagent to remove the pollutant extracted (p-Cresol) and to recover the surfactant solution. The pH of the soil washing wastewater was about 6.5 and did not change significantly during the Fenton Reagent treatment. Total conversions of p-Cresol were observed, at very short times, at the conditions tested for the Fenton reaction (100mgL−1 of H2O2 and 10mgL−1 of Fe2+). The hydrogen peroxide was not totally exhausted, showing conversions near 60% at 120min. Besides, the removal of Tween 80 during the Fenton’s reaction was lower than 10%, which suggests that the reaction is mainly selective to p-Cresol degradation. The toxicity of the liquids, measured by Microtox bioassay, was significantly reduced after the oxidation reaction, suggesting the negligible formation of degradation intermediates with higher toxicity than p-Cresol.

Using Fenton's Reagent as a Polishing Step for Biologically Treated Landfill Leachate

Using Fenton's Reagent as a Polishing Step for Biologically Treated Landfill LeachateWhen discharged to publically owned treatment works (POTWs), landfill leachates can interfere with the installed treatment facilities. Biological treatment is ineffective for the removal of some of the bio-refractory organic matter, such as UV254 quenching substances and inorganic nitrogen species. Fenton's reagent treatment for biologically treated landfill...Author(s)Renzun ZhaoAbhinav GuptaJohn T. NovakDouglas Goldsmith CSourceProceedings of the Water Environment FederationDocument typeConference PaperPublisherWater Environment FederationPrint publication date Oct, 2013ISSN1938-6478DOI10.2175/193864713813667601Volume / Issue2013 / 19Content sourceWEFTECCopyright2013Word count159

Influence of Fenton's reagent treatment on electrochemical properties of graphite felt for all vanadium redox flow battery

An environmental, economic and highly effective method for carbon fiber hydroxylated-functionalization based on Fenton's reagent treatment is used to improve the electrochemical activity of graphite felt (GF) as the positive electrode in all vanadium redox flow battery (VRFB). The effect of H2O2 content in Fenton's reagent on the structure and electrochemical properties of GF is investigated. The scanning electron microscope (SEM) indicates that the surface of the treated GF is etched increasingly with the content of H2O2. The Fourier transformation infrared (FTIR) spectroscopy shows that the peak intensity of hydroxyl groups on the treated felt is increased with the H2O2 concentration, which is further verified by X-ray photoelectron spectroscopy (XPS). Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) show that the treated sample exhibits a higher electrochemical activity. A VRFB with the treated GF as electrodes exhibits higher coulombic, voltage and energy efficiency (98.8%, 75.1% and 74.2%) than that with the untreated GF (93.9%, 72.1% and 67.7%) at 60mAcm−2, and this method is even superior when compared with the reported methods.

Study on Different Advanced Oxidations of Cafeteria Wastewater

KMnO4 was selected as oxidizers for the oxidation and degradation of cafeteria wastewater. The treatment effects were evaluated by the changes of COD and BOD5 parameters. Orthogonal experiments were designed to optimize the processing conditions based on the single affected factor. The optimized controlling conditions for KMnO4 treatment process were KMnO4=0.3 mmol/L, pH=2, reaction time=60 minutes respectively. The COD removal ratios using KMnO4, ClO2, Fenton reagent treatment were 26%, 55% and 82% respectively. It showed that of Fenton was highest. But after its oxidation, it created other refractory substance and the produced sludge was also difficult to settle down. When using ClO2, the pH in process is closer to neutral, thus saved large quantity of acid. The treatment using KMnO4 showed there was little refractory precipitation, but its COD removal was too low.

Study on Advanced Oxidation of Cafeteria Wastewater Using Fenton Reagent

Fenton reagent was selected as oxidizers for the oxidation and degradation of cafeteria wastewater. The treatment effects were evaluated by the changes of COD and BOD5 parameters. The effects of Fenton reagent ratio, dosage of FeSO4•7H2O and pH value on wastewater treatment under normal temperature and pressure were investigated, the oxidation regularity is initially discovered as well. Orthogonal experiments were designed to optimize the processing conditions based on the single affected factor. The optimized controlling conditions for Fenton reagent treatment process is FeSO4•7H2O=1mmol/L, pH=3, H2O2/Fe2+=3.5:1, reaction time=60min. With Fenton reagent treatment the COD removal ratio was raised up to 94%. Compared with biological process, it saved land occupation and was more suitable for regions which lacked of land space.

Protection of Melanized Cryptococcus neoformans from Lethal Dose Gamma Irradiation Involves Changes in Melanin's Chemical Structure and Paramagnetism

Certain fungi thrive in highly radioactive environments including the defunct Chernobyl nuclear reactor. Cryptococcus neoformans (C. neoformans), which uses L-3,4-dihydroxyphenylalanine (L-DOPA) to produce melanin, was used here to investigate how gamma radiation under aqueous aerobic conditions affects the properties of melanin, with the aim of gaining insight into its radioprotective role. Exposure of melanized fungal cell in aqueous suspensions to doses of γ-radiation capable of killing 50 to 80% of the cells did not lead to a detectable loss of melanin integrity according to EPR spectra of melanin radicals. Moreover, upon UV-visible (Xe-lamp) illumination of melanized cells, the increase in radical population was unchanged after γ-irradiation. Gamma-irradiation of frozen cell suspensions and storage of samples for several days at 77 K however, produced melanin modification noted by a reduced radical population and reduced photoresponse. More direct evidence for structural modification of melanin came from the detection of soluble products with absorbance maxima near 260 nm in supernatants collected after γ-irradiation of cells and cell-free melanin. These products, which include thiobarbituric acid (TBA)-reactive aldehydes, were also generated by Fenton reagent treatment of cells and cell-free melanin. In an assay of melanin integrity based on the metal (Bi+3) binding capacity of cells, no detectable loss in binding was detected after γ-irradiation. Our results show that melanin in C. neoformans cells is susceptible to some damage by hydroxyl radical formed in lethal radioactive aqueous environments and serves a protective role in melanized fungi that involves sacrificial breakdown.

The antagonistic effect of hydroxyl radical on the development of a hypersensitive response in tobacco

Reactive oxygen species (ROS) are important signalling molecules in living cells. It is believed that ROS molecules are the main triggers of the hypersensitive response (HR) in plants. In the present study of the effect of riboflavin, which is excited to generate ROS in light, on the development of the HR induced by the elicitin protein ParA1 in tobacco (Nicotiana tabacum), we found that the extent of the ParA1-induced HR was diminished by hydroxyl radical (OH•), a type of ROS. As compared with the zones treated with ParA1 only, the HR symptom in the zones that were infiltrated with ParA1 plus riboflavin was significantly diminished when the treated plants were placed in the light. However, this did not occur when the plants were maintained in the dark. Trypan blue staining and the ion leakage measurements confirmed HR suppression in the light. Further experiments proved that HR suppression is attributed to the involvement of the photoexcited riboflavin, and that the suppression can be eliminated with the addition of hydrogen peroxide scavengers or OH• scavengers. Fenton reagent treatment and EPR measurements demonstrated that it is OH• rather than hydrogen peroxide that contributes to HR suppression. Accompanying the endogenous OH• formation, suppression of the ParA1-induced HR occurred in the tobacco leaves that had been treated with high-level abscisic acid, and that suppression was also removed by OH• scavengers. These results offer evidence that OH•, an understudied and little appreciated ROS, participates in and modulates biologically relevant signalling in plant cells.

Advanced oxidation of amoxicillin by Fenton's reagent treatment

Advanced oxidation of amoxicillin was realized in aqueous solution by using Fenton's reagent treatment. Box–Behnken statistical experiment design was used to determine the effects of reagent concentrations on amoxicillin degradation and mineralization. Amoxicillin (10–200 mg L −1), hydrogen peroxide (10–500 mg L −1) and Fe(II) (0–50 mg L −1) concentrations were considered as independent variables in batch oxidation experiments. Percent amoxicillin and total organic carbon (TOC) removals (mineralization) were considered as the objective functions to be maximized. Required reaction times were 2.5 min and 15 min, respectively for degradation and mineralization of amoxicillin. Both peroxide and amoxicillin concentrations affected the extent of amoxicillin degradation and mineralization. Complete amoxicillin degradation was obtained within 2.5 min while 37% mineralization took place within 15 min. The optimum peroxide/Fe/amoxicillin ratio resulting in complete amoxicillin degradation and 37% mineralization was 255/25/105 mg L −1.

Degradation of microcystin-LR by ozone in the presence of Fenton reagent

In this study the effectiveness and feasibility of the degradation of microcystin-LR (MC-LR) using a combined method ozone/Fenton reagent was investigated. The decomposition of the toxin was determined by the chromatographic technique. The effect of the Fenton reaction on the ozonation was observed at various concentrations of ozone at pH 3.0 and 6.8. A low concentration of ozone (0.01 mg/L) given simultaneously with Fenton reagent was more effective in MC-LR degradation than ozone or Fenton reagent treatment individually regardless of the pH. At higher concentrations of ozone the use together with Fenton reagent at pH 6.8 was less efficient in MC-LR degradation than treatment with ozone alone, whereas at pH 3.0 Fenton process turned out to be more effective. The mixture of ozone and hydrogen peroxide was more striking than using ozone with Fenton reagent regardless of the pH. The complete degradation of MC-LR was achieved using ozone alone at a concentration of 0.10 mg/L, whereas the same result using ozonation with Fenton reagent required a dose of ozone of 0.20 mg/L at pH 6.8. In acidic pH the total removal of MC-LR was achieved using ozone alone at a concentration of 0.20 mg/L and the same result was obtained for the combined method of ozone/Fenton reagent.

Effect of Fenton's reagent on O/W emulsions stabilized by black liquor

The effect of Fenton's reagent (FR) on surface and dispersion properties of black liquor (BL) was investigated. These properties were compared to those of indulin C (IC), a commercial lignin, and egg lecithin (Le). FR was applied at two different bulk concentrations of H 2O 2 (160 and 320 mM). At pH 8, a minimum in surface tension for the Fenton treated BL was observed. The dispersant ability of BL, IC and Le in oil-in-water (O/W) emulsions was studied by measuring emulsion stability and drop size. It was found that the surface activity and emulsifying capability of BL were higher than those of IC. The emulsifying capability of Le was improved by the FR treatment at low H 2O 2 concentration.

Chemical oxidation of tetrachloroethene in a fractured saprolite/bedrock aquifer

AbstractTwo chemical oxidizers, Fenton's Reagent (FR) and sodium permanganate (NaMnO4), were used to remediate groundwater contaminated by tetrachloroethene (PCE) in a fractured saprolite and bedrock aquifer in Rockville, Maryland. Initial PCE concentrations ranged from 11 to 25,000 μg/L, averaging 8,684 μg/L in March 2000. A total of 28,256 pounds of hydrogen peroxide (as 35 percent solution) and iron catalyst were injected during the FR treatment program. The FR failed to achieve the desired clean‐up goal, after which 11,114 pounds of NaMnO4 (as 40 percent solution) were diluted to a 20 percent solution and injected into the aquifer. An additional 855 pounds of dilute NaMnO4 was later injected, which ultimately reduced the original PCE mass by an estimated 95 percent through November 2001. © 2003 Wiley Periodicals, Inc.

In Situ Oxidation Using a Circum-Neutral Modified Fenton's Reagent—Treatment of Mixed Organic Contaminants in a Low Permeability Aquifer

In Situ Oxidation Using a Circum-Neutral Modified Fenton's Reagent—Treatment of Mixed Organic Contaminants in a Low Permeability Aquifer

Degradation of olive mill wastewater by the combination of Fenton's reagent and ozonation processes with an aerobic biological treatment

Degradation of olive mill wastewater (OMW) by means of two chemical oxidation processes (Fenton's reagent and ozonation) and their consecutive treatments with aerobic microorganisms have been studied. Fenton's reagent treatment moderately reduces COD and to a greater extent the polyphenolic compounds. Ozonation contributed to low conversion of COD and moderate reduction of polyphenols. The aerobic biological treatments degrade to values higher than 70% and 90% for COD and polyphenolic compounds, respectively. A kinetic study has been carried out in each process, determining the representative kinetic parameters of each model.