Fenton-like Oxidation Process Research Articles

Treatment of spent radioactive anionic exchange resins using Fenton-like oxidation process

The treatment and disposal of spent radioactive ion exchange resins produced during the operation of the nuclear facilities is of great importance to minimize their potential hazard to the environments. In this paper, the degradation and disintegration of spent anionic resins was carried out using the Fenton-like oxidation process to reduce their volume and weight. The influencing factors, such as temperature, initial concentration of Cu(II), pH value were determined. The experimental results showed that the degradation efficiency (in term of COD removal rate), weight and volume reduction percentage was 97%, 68%, 75%, respectively, when pH was 3, Cu(II) concentration was 0.5M and temperature was 95±2°C. The SEM observation indicated the process of resin disintegration and dissolution. The Raman and FTIR spectrum provided the information of functional groups change of resins during oxidation process, which is useful for further studying the intermediate products of resin degradation. The possible mechanism of anionic resins degradation was proposed to explain why they were difficult to degrade. Fenton-like oxidation process was a potential and promising method for significant volume reduction of spent radioactive resins.

A combined process of adsorption and Fenton-like oxidation for furfural removal using zero-valent iron residue

In this study, the feasibility of using a combined adsorption and Fenton-like oxidation process (with zero-valent iron (ZVI) residue from heat wraps as an absorbent and catalyst) to remove furfural in the solution was evaluated. The influencing parameters (e.g. pH, H2O2 concentration, initial furfural concentration) and the reusability of ZVI residue (to replace the iron powder) were estimated. The ZVI residue was found to have much better adsorption effect on furfural at pH 2.0 compared with pH 6.7. For Fenton-like reaction alone with ZVI residue, the highest furfural removal of 97.5% was observed at the concentration of 0.176 mol/L H2O2, and all of the samples had >80% removal efficiency at different initial furfural concentrations of 2, 10, 20, 30 and 40 mmol/L. However, with a combined adsorption and Fenton-like oxidation, the removal efficiency of furfural was nearly 100% for all treatments. The ZVI residue used for furfural removal was much better than that of iron powder in the Fenton-like reaction at a seven-cycle experiment. This study suggests the combined process of adsorption and Fenton-like oxidation using ZVI residue is effective for the treatment of furfural in the liquid.

Disintegration and dissolution of spent radioactive cationic exchange resins using Fenton-like oxidation process

The treatment and disposal of the spent radioactive resins is essential for the sustainable development of the nuclear industry. In this paper, the disintegration and dissolution of spent cationic resins were studied by Fenton-like process. The influencing factors on resin dissolution, such as pH, temperature, type and concentration of catalysts were evaluated. The results showed that the spent resins could be effectively dissolved at pH<1, [Fe2+]=0.2M and T=97±2°C. Chemical oxygen demand (COD) reduction rate was more than 99%. The scanning electron microscopy and the Raman spectrum were used to observe the morphological changes of the spent resins during the dissolution process. Fenton-like oxidation is an efficient method for the volume reduction and stabilization of the spent resins before further immobilization.

Final purification of synthetic olive oil mill wastewater treated by chemical oxidation using ion exchange: Study of operating parameters

In this research work, ion exchange (IE) is presented as a suitable option for purification of olive oil mill wastewater (OMW) previously treated by means of a secondary treatment (OMWST). This pretreatment consisted in Fenton-like oxidation process, followed by coagulation–flocculation and filtration through olive stones. The parametric requirements for drinking water production or at least for public waterways discharge were achieved using a combination of two IE columns working in series at bench scale. The IE resins used in this study were Dowex Marathon C and Amberlite IRA-67. The effect of contact time, operating temperature and flow rate on simultaneous removal of sodium, total iron, chloride and phenols (the major pollutant species in OMWST) were investigated. Removal percentages of sodium, chloride and total iron increased with incrementing the contact time. Equilibrium was obtained in about 30min for all ions and ion concentrations values determined were lower than the maximum levels for drinking water standards. On the other hand, adsorption efficiencies of sodium, total iron and chloride ions were found to be not considerably affected by the operating temperature. The highest phenols removal percentage (around 100%) was obtained in the first minutes for 298K and 10L/h.

Effect of Nano-Fe&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;/Goldmine Complex on Dyeing Wastewater Treatment

Nano-Fe2O3/goldmine complex was obtained by chemical coprecipitation on the surface of goldmine waste-solid. And its application as the heterogeneous catalyst in Fenton-like advanced oxidation processes (AOPs) was discussed for the degradation of dyeing wastewater. It was found that advanced oxidation processes play an important role to the removal of dyeing wastewater. And the best removal rate of 15400mg/L dyeing wastewater reached up to 63.1% with the presence of 50g/L dosage of nano-Fe2O3/goldmine complex and 50mL/L concentration of H2O2 at 50°C with pH=3.

Anchored Iron Ligands as an Efficient Fenton-Like Catalyst for Removal of Dye Pollutants at Neutral pH

The development of a pH-tolerant Fenton-like catalyst is an active and challenging research front in the area of environmental engineering. In the present work, a novel catalyst iron−γ-aminopyridine ligand (FeAPy) was prepared and immobilized on activated carbon fibers (ACFs) by a covalent bond to obtain a heterogeneous FeAPy-ACFs. FeAPy-ACFs present a pH-tolerant microenvironment for the Fenton-like oxidation process, which exhibits remarkable catalytic ability across a wide pH range from acidic to alkaline. At neutral pH, employing hydrogen peroxide as an oxidant, the FeAPy-ACFs showed enhanced catalytic ability to degrade hazardous environmental pollutants Acid Red 1 (AR1) dyes and avoid secondary pollution with regard to FeAPy. FeAPy-ACFs are stable and remain efficient in repetitive test cycles with no obvious decrease of catalytic activity. Moreover, in comparison to most reported supports for Fenton-like catalyst, the introduction of ACFs contributed specifically to the activity improvement of FeAP...

Comparing treatment methods that remove color from the effluent of an Organized Industrial District (OID)

This study investigates the treatability, in terms of color removal, of an effluent taken from an Organized Industrial District wastewater treatment plant located in Bursa, western Turkey. To remove the color, chemical coagulation, Fenton and Fenton-like oxidation, ozonation, adsorption, and membrane processes were employed, and the results were compared. In coagulation experiments, maximum color removal (87.4%) was obtained at pH 12.2 with a dose of 240 mg/L MgCl2 + Ca(OH)2. Fenton and Fenton-like oxidation processes showed high color removal efficiencies (93.1 and 80%, respectively) from the evaluated effluents. The best color removal (93.6%) in this study was achieved by an ozonation process at a dose of 8 g/L-min ozone with a pH of 12 and a contact time of 3 min. In addition to the color removal efficiencies for the applied processes, their associated operating costs were also calculated.

COD REMOVAL FROM SYNTHETIC WASTEWATER CONTAINING AZITHROMYCIN USING COMBINED COAGULATION AND A FENTON-LIKE PROCESS

In this study, the COD removal of Azithromycin from synthetic wastewater (produced to have a composition similar to industrial wastewater) using a Fenton-like (Fe ˚ /H2O2) system in combination with coagulation has been investigated. Chemical oxygen demand (COD) was selected as the main parameter to assess treatment efficacy in the current study (COD˚ = 390mg/Lequivalent to 200mg/LAzithromycin). First, the coagulation process was carried out on the synthetic wastewater and the optimum conditions were determined and calculated. According to the results of this experiment, Poly Aluminum Chloride (PAX-18) was selected as the most appropriate coagulant. The results of the coagulation process indicated that COD removal efficacy under the optimum conditions of PAX-18 100mg/Land pH 7.0 was 82.14%. Then, a Fenton-like oxidation process was performed on the effluent of the coagulation process. The optimum conditions were determined and calculated for the Fenton-like process: [Fe ˚ ] = 0.36 mM/l, [H2O2]= 0.38 mM/l, and [pH]=7.0. Finally, in combined treatment (coagulation and the Fenton-like process together), the COD removal rose to 96.89% under optimum conditions. The findings of this study demonstrate that the combined processes of coagulation and Fenton-like oxidation under optimum conditions can play an important role in the COD removal of Azithromycin from industrial wastewater.

Fenton’s oxidation of para-chlorophenol with zero-valent iron

Para-chlorophenol (para-cp), a chlorophenol derivative, is potentially a pollutant that represents an important environmental problem, because of its toxic effects on the environment. In this study, the removal of para-cp from synthetic wastewater using a Fenton-like (Fe˚/H2O2) system has been investigated. A Fenton-like oxidation process was performed on the synthetic wastewater and the optimum conditions were determined and calculated. According to the results of this experiment, removal efficiency under the optimum conditions of [Fe˚] = 0.0035 M, [H2O2] = 0.0014 M, and [pH] = 4.0 was 93.89% in 5 min. Increasing chloride ions from 0 to 4.6 mg/l and decreasing UV215 absorbance from 1 to 0.4 indicated that the generated intermediates’ toxicity was reduced and the degradability was enhanced.

Rapid Mineralization of Rhodamine B Wastewater by Microwave Synergistic Fenton-Like Oxidation Process

The coulpling method of microwave irradiation and Fenton-like reaction with magnetic nanomaterials of CuFe2O4 as the catalyst was used for degradation of Rhodamine B wastewater. Factors affecting the degradation rate of Rhodamine B such as H2O2 dosage, CuFe2O4 dosage, Rhodamine B initial concentration, reaction temperature and so on were investigated systematically. The experimental results showed that the microwave-assisted Fenton-like process using H2O2/CuFe2O4 was the most effective treatment process compared with other methods. Unlike the conventional Fenton reactions, which are catalyzed by homogeneous catalysts/promoters, the nanopowder CuFe2O4 catalyst is easily collected by an external magnetic field and remains efficient in reuse. The results showed that under the given conditions (80°C, pH = 4, Rhodamine B initial concentration = 100mg/L, CuFe2O4 dose = 0.375g/L, H2O2 dose = 2.5mL/L, Reaction time = 2min), the removal rate of Rhodamine B could reach nearly 100%. Moreover, the COD determination results showed that under above conditions, the COD value could reach zero.

Kinetic of C.I. Reactive Black 5 by Fenton-Like Oxidation

The decolorization kinetic of C.I. Reactive Black 5 was studied using Fenton-like oxidation. The effect of the major system parameters, such as initial pH of the solution, concentration of H2O2, concentration of Fe3+ and reaction temperature on the kinetics was determined. The results indicate that the operating parameters, such as initial pH of dye solution, initial concentration of Fe2+ and H2O2, reaction temperature, have strong influences on the degradation of C.I. Reactive Black 5 by Fenton-like oxidation process. In addition, it was also found that the decolorization of C.I. Reactive Black 5 followed the first-order kinetics well.

Use of pipe deposits from water networks as novel catalysts in paraquat peroxidation

The present work intends to evaluate the possibility of using real pipe deposits as peroxidation catalysts (i.e., in the heterogeneous Fenton-like oxidation process) to degrade the pesticide paraquat in water. The valorisation of these loosely or firmly attached materials, often discarded after networks cleaning or maintenance, respectively, is envisaged in off-line waste water treatment applications. They may however be also applicable in situ, for instance in case of a contamination event of water networks.Four iron-containing real deposits, herein called S1, S2, S3 and S4, were considered. The results revealed that two of them (samples S1 and S2) exhibit good catalytic performance in the pesticide degradation and mineralization. Another one (sample S3) has goethite and also some metals in its composition that can decompose the hydrogen peroxide, compromising the peroxidation process. The calcium rich deposit, S4, is only useful as catalyst when the medium pH is adjusted to the required acidic values of Fenton’s reaction. Even so, other deposits showed good performances even at neutral pH values, which is related with their low pHpzc values. It was found that depending on the solid nature, the catalytic performance can be predominantly due to the presence of the solid phase, but in some cases the homogenous process resulting from leached ions play an important role. With the deposit that exhibited the best performance, an exhaustive study of the pH effect was done, showing the stability of these materials at neutral conditions.

Treatment of Dye Wastewater by Nano-Ferrous Modified Bentonite Assisted Advanced Oxidation Processes

Degradation of dye wastewater was studied by using nanoferrous modified bentonite as the heterogeneous catalyst for a Fenton-like oxidation. By comparing the effect of homogeneous Fenton reactions as well as heterogeneous Fenton-like process for nanomodified bentonite, it is found that the advanced oxidation processes assisted by nanoferrous/bentonite complexes exhibit the stronger degradation capacity. And the removal rate of Fenton-like reaction increased from 23.6% to 75.5% when the ferrous concentration increasing from 20 to 100mmol/L. Being compared with homogeneous Fenton reactions, 20% increased degradation efficiencies is obtained by Fenton-like oxidation process for nanomodified bentonite under 6g nanoferrous/bentonite complexes in 100mL dye wastewater.

Fenton + Fenton-like Integrated Process for Carbamazepine Degradation: Optimizing the System

A factorial central composite orthogonal and rotatable design was employed to optimize the carbamazepine degradation using an integrated Fenton + Fenton-like oxidation process. The pH and the initi...

Remediation of TCE-contaminated groundwater using acid/BOF slag enhanced chemical oxidation

The objective of this study was to evaluate the potential of applying acid/H 2O 2/basic oxygen furnace slag (BOF slag) and acid/ S 2 O 8 2 - /BOF slag systems to enhance the chemical oxidation of trichloroethylene (TCE)-contaminated groundwater. Results from the bench-scale study indicate that TCE oxidation via the Fenton-like oxidation process can be enhanced with the addition of BOF slag at low pH (pH = 2–5.2) and neutral (pH = 7.1) conditions. Because the BOF slag has iron abundant properties (14% of FeO and 6% of Fe 2O 3), it can be sustainably reused for the supplement of iron minerals during the Fenton-like or persulfate oxidation processes. Results indicate that higher TCE removal efficiency (84%) was obtained with the addition of inorganic acid for the activation of Fenton-like reaction compared with the experiments with organic acids addition (with efficiency of 10–15% lower) (BOF slag = 10 g L −1; initial pH = 5.2). This could be due to the fact that organic acids would compete with TCE for available oxidants. Results also indicate that the pH value had a linear correlation with the observed first-order decay constant of TCE, and thus, lower pH caused a higher TCE oxidation rate.

Removal of Endocrine Disrupting Chemicals in Wastewater Treatment by Fenton-Like Oxidation

The presence of endocrine-disrupting chemicals (EDCs) in wastewater effluent is a major concern to the scientific community. This research effort was aimed at investigating Fenton-like degradation of two EDCs 17β-estradiol (E2) and 17α-ethinylestradiol (EE2). The results of the study showed that E2 and EE2 were effectively removed by the Fenton-like oxidation process. Removal efficiencies of 95% and 98% at ferric concentration of 1 × 10−3 M (58.6 mg l−1) were achieved for E2 and EE2, respectively. The kinetics of Fenton-like degradation of E2 and EE2 were adequately described by the pseudo second order kinetic model. Values of 27.8 and 22.5 kJ mol−1 were obtained for the activation energy for E2 and EE2, respectively, from the Arrhenius-type plot, showing that the process does not just involve radical reactions but also intermediate reaction steps involving radical–molecule or ion–molecule reactions. The presence of high dissolved organics in wastewater significantly reduced the removal efficiencies. The reaction by-products for E2 and EE2 were more stable to the oxidation process and more readily biodegradable. Fenton-like oxidations therefore offers a promising alternative for the removal of these EDCs in wastewater treatment applications at the tertiary treatment stage.

Fenton-like oxidation of reactive black 5 solution using iron–Montmorillonite K10 catalyst

Decolorization of reactive azo dye, reactive black 5 (RB5), was conducted using Fe(III) immobilized on Montmorillonite K10 (MK10) as a catalyst in the presence of H 2O 2 using Fenton-like oxidation process. The effect of different parameters such as iron ions loading on supported catalyst, catalyst dosage, initial pH of dye solution, initial concentration of H 2O 2 and dye and reaction temperature on the decolorization efficiency of the process were studied. The results indicated that by using 12 mM of H 2O 2 and 3.50 g L −1 of the 0.11 wt.% Fe(III) oxide on MK10 catalyst at pH of 2.5, 99% of decolorization efficiency was achieved within 150 min in a batch process.

Treatment of Fuel-Oil Contaminated Soils by Biodegradable Surfactant Washing Followed by Fenton-Like Oxidation

Among petroleum-hydrocarbon pollutants, fuel-oil is more difficult to treat compared to gasoline and diesel fuel. The objectives of this bench-scale study were to: (1) develop a two-stage remedial system consisting of surfactant washing followed by Fenton-like oxidation process to remediate fuel-oil contaminated soils; (2) evaluate the effects of residual surfactant and soil organic matter (SOM) on the efficiency of Fenton-like oxidation; (3) evaluate the effect of potassium dihydrogen phosphate ( KH2 PO4 ) addition on the stability of H2 O2 and oxidation efficiency; and (4) evaluate the possible oxidation products after the oxidation process. In the surfactant washing stage, biodegradable surfactant, Simple Green (SG) ( 50 g L−1 ) , was applied to flush fuel-oil contaminated soils with initial total petroleum-hydrocarbons (TPHs) concentration of 50,000 mg kg−1 . Results show that approximately 90% of TPH could be removed after washing with 45 pore volumes (PVs) of SG followed by 25 PVs of deionized wat...

Azo-dye Orange II degradation by heterogeneous Fenton-like reaction using carbon-Fe catalysts

In this work, the degradation and mineralization of the non-biodegradable azo dye Orange II (OII) was studied, making use of a heterogeneous Fenton-like oxidation process. For that, hydrogen peroxide activation was achieved by means of two different carbon-based catalysts, which have been impregnated with 7wt% of iron. The carbon supports employed are quite different, one of them being an activated carbon prepared from agricultural by-products (olive stone), while the other one is a carbon aerogel, prepared by carbonization of an organic resorcinol–formaldehyde polymer. The solids have been characterized using several techniques, namely N2 and CO2 adsorption at −196 and 0°C, respectively, mercury porosimetry, scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), x-ray diffraction (XRD) and x-ray photoelectron spectroscopy (XPS). Then, the catalyst's performance in the Fenton-like oxidation of OII was compared, and the effects of the most relevant operating conditions (pH, catalyst concentration, H2O2 concentration and temperature) analyzed for the most promising one (the carbon aerogel based catalyst). In this catalyst, characterization data point for a very good iron dispersion on the carbon surface. This sample showed very good catalytic performances, with mineralization degrees as high as 90%. However, iron leaching from the support is also considerable leading to a progressive deactivation in consecutive reaction cycles.

Effect of voltage gradient on integrated electrochemical remediation of contaminant mixtures

This paper evaluates the effect of voltage gradient on the efficiency of integrated electrochemical remediation (IECR) of low permeability soils contaminated with both heavy metals and polycyclic aromatic hydrocarbons (PAHs). The IECR remediation process aims to oxidize organic contaminants within the soil by the electro-osmotic delivery of hydrogen peroxide (H2O2) and a Fenton-like oxidation process, as well as simultaneously removing heavy metals by electro-osmotic advection and electromigration. In Fenton-like oxidation, the native soil iron is utilized as a catalyst to decompose H2O2 to generate free hydroxyl radicals that oxidize PAHs into relatively benign products such as carbon dioxide, water and oxygen. A series of bench-scale experiments was performed on kaolin (a low permeability soil) spiked with nickel (a representative heavy metal) and phenanthrene (a representative PAH) each at a concentration of 500 mg per kg of dry soil under two voltage gradients, 1 and 2 VDC/cm. The H2O2 solution in two different concentrations at 5% and 10% was introduced at the anode, and each experiment was conducted for a total duration of four weeks. The results showed that increasing the voltage gradient from 1 VDC/cm to 2 VDC/cm did not increase the electro-osmotic delivery of H2O2 significantly. Phenanthrene removal from the soil was negligible in all the experiments; however, 28% and 34% of the phenanthrene were oxidized within the soil in the 5% and 10% H2O2 experiments, respectively, under 1 VDC/cm. The phenanthrene oxidation increased to about 32% and 42% under 5% and 10% H2O2 concentrations, respectively, under 2 VDC/cm. Nickel migrated towards the cathode and then precipitated close to the cathode, due to high pH conditions in all the experiments. Nickel migration was slightly higher in the case of 2 VDC/cm than in the case of 1 VDC/cm, due to greater migration of the acidic pH front towards the cathode under 2 VDC/cm. Overall, the results showed that an increase in the voltage gradient from 1 VDC/cm to 2 VDC/cm improved overall remedial performance slightly, and alternative strategies to increase H2O2 delivery and prevent precipitation of metals near the cathode are required for achieving significantly higher remedial efficiencies.